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linux/drivers/tty/serial/sh-sci.c
Wolfram Sang ae1b6b4c0a serial: sh-sci: simplify locking when re-issuing RXDMA fails 
Avoid a superfluous unlock/lock-pair by simply moving the printout to
the end of bailing out.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240506114016.30498-10-wsa+renesas@sang-engineering.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-10 11:48:33 +01:00

3568 lines
86 KiB
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Raw Blame History

// SPDX-License-Identifier: GPL-2.0
/*
* SuperH on-chip serial module support. (SCI with no FIFO / with FIFO)
*
* Copyright (C) 2002 - 2011 Paul Mundt
* Copyright (C) 2015 Glider bvba
* Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
*
* based off of the old drivers/char/sh-sci.c by:
*
* Copyright (C) 1999, 2000 Niibe Yutaka
* Copyright (C) 2000 Sugioka Toshinobu
* Modified to support multiple serial ports. Stuart Menefy (May 2000).
* Modified to support SecureEdge. David McCullough (2002)
* Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
* Removed SH7300 support (Jul 2007).
*/
#undef DEBUG
#include <linux/clk.h>
#include <linux/console.h>
#include <linux/ctype.h>
#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/ktime.h>
#include <linux/major.h>
#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/scatterlist.h>
#include <linux/serial.h>
#include <linux/serial_sci.h>
#include <linux/sh_dma.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sysrq.h>
#include <linux/timer.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#ifdef CONFIG_SUPERH
#include <asm/sh_bios.h>
#include <asm/platform_early.h>
#endif
#include "serial_mctrl_gpio.h"
#include "sh-sci.h"
/* Offsets into the sci_port->irqs array */
enum {
SCIx_ERI_IRQ,
SCIx_RXI_IRQ,
SCIx_TXI_IRQ,
SCIx_BRI_IRQ,
SCIx_DRI_IRQ,
SCIx_TEI_IRQ,
SCIx_NR_IRQS,
SCIx_MUX_IRQ = SCIx_NR_IRQS, /* special case */
};
#define SCIx_IRQ_IS_MUXED(port) \
((port)->irqs[SCIx_ERI_IRQ] == \
(port)->irqs[SCIx_RXI_IRQ]) || \
((port)->irqs[SCIx_ERI_IRQ] && \
((port)->irqs[SCIx_RXI_IRQ] < 0))
enum SCI_CLKS {
SCI_FCK, /* Functional Clock */
SCI_SCK, /* Optional External Clock */
SCI_BRG_INT, /* Optional BRG Internal Clock Source */
SCI_SCIF_CLK, /* Optional BRG External Clock Source */
SCI_NUM_CLKS
};
/* Bit x set means sampling rate x + 1 is supported */
#define SCI_SR(x) BIT((x) - 1)
#define SCI_SR_RANGE(x, y) GENMASK((y) - 1, (x) - 1)
#define SCI_SR_SCIFAB SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
SCI_SR(19) | SCI_SR(27)
#define min_sr(_port) ffs((_port)->sampling_rate_mask)
#define max_sr(_port) fls((_port)->sampling_rate_mask)
/* Iterate over all supported sampling rates, from high to low */
#define for_each_sr(_sr, _port) \
for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--) \
if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
struct plat_sci_reg {
u8 offset, size;
};
struct sci_port_params {
const struct plat_sci_reg regs[SCIx_NR_REGS];
unsigned int fifosize;
unsigned int overrun_reg;
unsigned int overrun_mask;
unsigned int sampling_rate_mask;
unsigned int error_mask;
unsigned int error_clear;
};
struct sci_port {
struct uart_port port;
/* Platform configuration */
const struct sci_port_params *params;
const struct plat_sci_port *cfg;
unsigned int sampling_rate_mask;
resource_size_t reg_size;
struct mctrl_gpios *gpios;
/* Clocks */
struct clk *clks[SCI_NUM_CLKS];
unsigned long clk_rates[SCI_NUM_CLKS];
int irqs[SCIx_NR_IRQS];
char *irqstr[SCIx_NR_IRQS];
struct dma_chan *chan_tx;
struct dma_chan *chan_rx;
#ifdef CONFIG_SERIAL_SH_SCI_DMA
struct dma_chan *chan_tx_saved;
struct dma_chan *chan_rx_saved;
dma_cookie_t cookie_tx;
dma_cookie_t cookie_rx[2];
dma_cookie_t active_rx;
dma_addr_t tx_dma_addr;
unsigned int tx_dma_len;
struct scatterlist sg_rx[2];
void *rx_buf[2];
size_t buf_len_rx;
struct work_struct work_tx;
struct hrtimer rx_timer;
unsigned int rx_timeout; /* microseconds */
#endif
unsigned int rx_frame;
int rx_trigger;
struct timer_list rx_fifo_timer;
int rx_fifo_timeout;
u16 hscif_tot;
bool has_rtscts;
bool autorts;
};
#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
static struct sci_port sci_ports[SCI_NPORTS];
static unsigned long sci_ports_in_use;
static struct uart_driver sci_uart_driver;
static inline struct sci_port *
to_sci_port(struct uart_port *uart)
{
return container_of(uart, struct sci_port, port);
}
static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
/*
* Common SCI definitions, dependent on the port's regshift
* value.
*/
[SCIx_SCI_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 8 },
[SCBRR] = { 0x01, 8 },
[SCSCR] = { 0x02, 8 },
[SCxTDR] = { 0x03, 8 },
[SCxSR] = { 0x04, 8 },
[SCxRDR] = { 0x05, 8 },
},
.fifosize = 1,
.overrun_reg = SCxSR,
.overrun_mask = SCI_ORER,
.sampling_rate_mask = SCI_SR(32),
.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
},
/*
* Common definitions for legacy IrDA ports.
*/
[SCIx_IRDA_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 8 },
[SCBRR] = { 0x02, 8 },
[SCSCR] = { 0x04, 8 },
[SCxTDR] = { 0x06, 8 },
[SCxSR] = { 0x08, 16 },
[SCxRDR] = { 0x0a, 8 },
[SCFCR] = { 0x0c, 8 },
[SCFDR] = { 0x0e, 16 },
},
.fifosize = 1,
.overrun_reg = SCxSR,
.overrun_mask = SCI_ORER,
.sampling_rate_mask = SCI_SR(32),
.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
},
/*
* Common SCIFA definitions.
*/
[SCIx_SCIFA_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x20, 8 },
[SCxSR] = { 0x14, 16 },
[SCxRDR] = { 0x24, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCPCR] = { 0x30, 16 },
[SCPDR] = { 0x34, 16 },
},
.fifosize = 64,
.overrun_reg = SCxSR,
.overrun_mask = SCIFA_ORER,
.sampling_rate_mask = SCI_SR_SCIFAB,
.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
},
/*
* Common SCIFB definitions.
*/
[SCIx_SCIFB_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x40, 8 },
[SCxSR] = { 0x14, 16 },
[SCxRDR] = { 0x60, 8 },
[SCFCR] = { 0x18, 16 },
[SCTFDR] = { 0x38, 16 },
[SCRFDR] = { 0x3c, 16 },
[SCPCR] = { 0x30, 16 },
[SCPDR] = { 0x34, 16 },
},
.fifosize = 256,
.overrun_reg = SCxSR,
.overrun_mask = SCIFA_ORER,
.sampling_rate_mask = SCI_SR_SCIFAB,
.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
},
/*
* Common SH-2(A) SCIF definitions for ports with FIFO data
* count registers.
*/
[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCSPTR] = { 0x20, 16 },
[SCLSR] = { 0x24, 16 },
},
.fifosize = 16,
.overrun_reg = SCLSR,
.overrun_mask = SCLSR_ORER,
.sampling_rate_mask = SCI_SR(32),
.error_mask = SCIF_DEFAULT_ERROR_MASK,
.error_clear = SCIF_ERROR_CLEAR,
},
/*
* The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
* It looks like a normal SCIF with FIFO data, but with a
* compressed address space. Also, the break out of interrupts
* are different: ERI/BRI, RXI, TXI, TEI, DRI.
*/
[SCIx_RZ_SCIFA_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x02, 8 },
[SCSCR] = { 0x04, 16 },
[SCxTDR] = { 0x06, 8 },
[SCxSR] = { 0x08, 16 },
[SCxRDR] = { 0x0A, 8 },
[SCFCR] = { 0x0C, 16 },
[SCFDR] = { 0x0E, 16 },
[SCSPTR] = { 0x10, 16 },
[SCLSR] = { 0x12, 16 },
[SEMR] = { 0x14, 8 },
},
.fifosize = 16,
.overrun_reg = SCLSR,
.overrun_mask = SCLSR_ORER,
.sampling_rate_mask = SCI_SR(32),
.error_mask = SCIF_DEFAULT_ERROR_MASK,
.error_clear = SCIF_ERROR_CLEAR,
},
/*
* Common SH-3 SCIF definitions.
*/
[SCIx_SH3_SCIF_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 8 },
[SCBRR] = { 0x02, 8 },
[SCSCR] = { 0x04, 8 },
[SCxTDR] = { 0x06, 8 },
[SCxSR] = { 0x08, 16 },
[SCxRDR] = { 0x0a, 8 },
[SCFCR] = { 0x0c, 8 },
[SCFDR] = { 0x0e, 16 },
},
.fifosize = 16,
.overrun_reg = SCLSR,
.overrun_mask = SCLSR_ORER,
.sampling_rate_mask = SCI_SR(32),
.error_mask = SCIF_DEFAULT_ERROR_MASK,
.error_clear = SCIF_ERROR_CLEAR,
},
/*
* Common SH-4(A) SCIF(B) definitions.
*/
[SCIx_SH4_SCIF_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCSPTR] = { 0x20, 16 },
[SCLSR] = { 0x24, 16 },
},
.fifosize = 16,
.overrun_reg = SCLSR,
.overrun_mask = SCLSR_ORER,
.sampling_rate_mask = SCI_SR(32),
.error_mask = SCIF_DEFAULT_ERROR_MASK,
.error_clear = SCIF_ERROR_CLEAR,
},
/*
* Common SCIF definitions for ports with a Baud Rate Generator for
* External Clock (BRG).
*/
[SCIx_SH4_SCIF_BRG_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCSPTR] = { 0x20, 16 },
[SCLSR] = { 0x24, 16 },
[SCDL] = { 0x30, 16 },
[SCCKS] = { 0x34, 16 },
},
.fifosize = 16,
.overrun_reg = SCLSR,
.overrun_mask = SCLSR_ORER,
.sampling_rate_mask = SCI_SR(32),
.error_mask = SCIF_DEFAULT_ERROR_MASK,
.error_clear = SCIF_ERROR_CLEAR,
},
/*
* Common HSCIF definitions.
*/
[SCIx_HSCIF_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCSPTR] = { 0x20, 16 },
[SCLSR] = { 0x24, 16 },
[HSSRR] = { 0x40, 16 },
[SCDL] = { 0x30, 16 },
[SCCKS] = { 0x34, 16 },
[HSRTRGR] = { 0x54, 16 },
[HSTTRGR] = { 0x58, 16 },
},
.fifosize = 128,
.overrun_reg = SCLSR,
.overrun_mask = SCLSR_ORER,
.sampling_rate_mask = SCI_SR_RANGE(8, 32),
.error_mask = SCIF_DEFAULT_ERROR_MASK,
.error_clear = SCIF_ERROR_CLEAR,
},
/*
* Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
* register.
*/
[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCLSR] = { 0x24, 16 },
},
.fifosize = 16,
.overrun_reg = SCLSR,
.overrun_mask = SCLSR_ORER,
.sampling_rate_mask = SCI_SR(32),
.error_mask = SCIF_DEFAULT_ERROR_MASK,
.error_clear = SCIF_ERROR_CLEAR,
},
/*
* Common SH-4(A) SCIF(B) definitions for ports with FIFO data
* count registers.
*/
[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x0c, 8 },
[SCxSR] = { 0x10, 16 },
[SCxRDR] = { 0x14, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
[SCTFDR] = { 0x1c, 16 }, /* aliased to SCFDR */
[SCRFDR] = { 0x20, 16 },
[SCSPTR] = { 0x24, 16 },
[SCLSR] = { 0x28, 16 },
},
.fifosize = 16,
.overrun_reg = SCLSR,
.overrun_mask = SCLSR_ORER,
.sampling_rate_mask = SCI_SR(32),
.error_mask = SCIF_DEFAULT_ERROR_MASK,
.error_clear = SCIF_ERROR_CLEAR,
},
/*
* SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
* registers.
*/
[SCIx_SH7705_SCIF_REGTYPE] = {
.regs = {
[SCSMR] = { 0x00, 16 },
[SCBRR] = { 0x04, 8 },
[SCSCR] = { 0x08, 16 },
[SCxTDR] = { 0x20, 8 },
[SCxSR] = { 0x14, 16 },
[SCxRDR] = { 0x24, 8 },
[SCFCR] = { 0x18, 16 },
[SCFDR] = { 0x1c, 16 },
},
.fifosize = 64,
.overrun_reg = SCxSR,
.overrun_mask = SCIFA_ORER,
.sampling_rate_mask = SCI_SR(16),
.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
},
};
#define sci_getreg(up, offset) (&to_sci_port(up)->params->regs[offset])
/*
* The "offset" here is rather misleading, in that it refers to an enum
* value relative to the port mapping rather than the fixed offset
* itself, which needs to be manually retrieved from the platform's
* register map for the given port.
*/
static unsigned int sci_serial_in(struct uart_port *p, int offset)
{
const struct plat_sci_reg *reg = sci_getreg(p, offset);
if (reg->size == 8)
return ioread8(p->membase + (reg->offset << p->regshift));
else if (reg->size == 16)
return ioread16(p->membase + (reg->offset << p->regshift));
else
WARN(1, "Invalid register access\n");
return 0;
}
static void sci_serial_out(struct uart_port *p, int offset, int value)
{
const struct plat_sci_reg *reg = sci_getreg(p, offset);
if (reg->size == 8)
iowrite8(value, p->membase + (reg->offset << p->regshift));
else if (reg->size == 16)
iowrite16(value, p->membase + (reg->offset << p->regshift));
else
WARN(1, "Invalid register access\n");
}
static void sci_port_enable(struct sci_port *sci_port)
{
unsigned int i;
if (!sci_port->port.dev)
return;
pm_runtime_get_sync(sci_port->port.dev);
for (i = 0; i < SCI_NUM_CLKS; i++) {
clk_prepare_enable(sci_port->clks[i]);
sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
}
sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
}
static void sci_port_disable(struct sci_port *sci_port)
{
unsigned int i;
if (!sci_port->port.dev)
return;
for (i = SCI_NUM_CLKS; i-- > 0; )
clk_disable_unprepare(sci_port->clks[i]);
pm_runtime_put_sync(sci_port->port.dev);
}
static inline unsigned long port_rx_irq_mask(struct uart_port *port)
{
/*
* Not all ports (such as SCIFA) will support REIE. Rather than
* special-casing the port type, we check the port initialization
* IRQ enable mask to see whether the IRQ is desired at all. If
* it's unset, it's logically inferred that there's no point in
* testing for it.
*/
return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
}
static void sci_start_tx(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
unsigned short ctrl;
#ifdef CONFIG_SERIAL_SH_SCI_DMA
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
u16 new, scr = sci_serial_in(port, SCSCR);
if (s->chan_tx)
new = scr | SCSCR_TDRQE;
else
new = scr & ~SCSCR_TDRQE;
if (new != scr)
sci_serial_out(port, SCSCR, new);
}
if (s->chan_tx && !kfifo_is_empty(&port->state->port.xmit_fifo) &&
dma_submit_error(s->cookie_tx)) {
if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
/* Switch irq from SCIF to DMA */
disable_irq_nosync(s->irqs[SCIx_TXI_IRQ]);
s->cookie_tx = 0;
schedule_work(&s->work_tx);
}
#endif
if (!s->chan_tx || s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE ||
port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
ctrl = sci_serial_in(port, SCSCR);
/*
* For SCI, TE (transmit enable) must be set after setting TIE
* (transmit interrupt enable) or in the same instruction to start
* the transmit process.
*/
if (port->type == PORT_SCI)
ctrl |= SCSCR_TE;
sci_serial_out(port, SCSCR, ctrl | SCSCR_TIE);
}
}
static void sci_stop_tx(struct uart_port *port)
{
unsigned short ctrl;
/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
ctrl = sci_serial_in(port, SCSCR);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
ctrl &= ~SCSCR_TDRQE;
ctrl &= ~SCSCR_TIE;
sci_serial_out(port, SCSCR, ctrl);
#ifdef CONFIG_SERIAL_SH_SCI_DMA
if (to_sci_port(port)->chan_tx &&
!dma_submit_error(to_sci_port(port)->cookie_tx)) {
dmaengine_terminate_async(to_sci_port(port)->chan_tx);
to_sci_port(port)->cookie_tx = -EINVAL;
}
#endif
}
static void sci_start_rx(struct uart_port *port)
{
unsigned short ctrl;
ctrl = sci_serial_in(port, SCSCR) | port_rx_irq_mask(port);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
ctrl &= ~SCSCR_RDRQE;
sci_serial_out(port, SCSCR, ctrl);
}
static void sci_stop_rx(struct uart_port *port)
{
unsigned short ctrl;
ctrl = sci_serial_in(port, SCSCR);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
ctrl &= ~SCSCR_RDRQE;
ctrl &= ~port_rx_irq_mask(port);
sci_serial_out(port, SCSCR, ctrl);
}
static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
{
if (port->type == PORT_SCI) {
/* Just store the mask */
sci_serial_out(port, SCxSR, mask);
} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
/* Only clear the status bits we want to clear */
sci_serial_out(port, SCxSR, sci_serial_in(port, SCxSR) & mask);
} else {
/* Store the mask, clear parity/framing errors */
sci_serial_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
}
}
#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
#ifdef CONFIG_CONSOLE_POLL
static int sci_poll_get_char(struct uart_port *port)
{
unsigned short status;
int c;
do {
status = sci_serial_in(port, SCxSR);
if (status & SCxSR_ERRORS(port)) {
sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
continue;
}
break;
} while (1);
if (!(status & SCxSR_RDxF(port)))
return NO_POLL_CHAR;
c = sci_serial_in(port, SCxRDR);
/* Dummy read */
sci_serial_in(port, SCxSR);
sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
return c;
}
#endif
static void sci_poll_put_char(struct uart_port *port, unsigned char c)
{
unsigned short status;
do {
status = sci_serial_in(port, SCxSR);
} while (!(status & SCxSR_TDxE(port)));
sci_serial_out(port, SCxTDR, c);
sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
}
#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
CONFIG_SERIAL_SH_SCI_EARLYCON */
static void sci_init_pins(struct uart_port *port, unsigned int cflag)
{
struct sci_port *s = to_sci_port(port);
/*
* Use port-specific handler if provided.
*/
if (s->cfg->ops && s->cfg->ops->init_pins) {
s->cfg->ops->init_pins(port, cflag);
return;
}
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
u16 data = sci_serial_in(port, SCPDR);
u16 ctrl = sci_serial_in(port, SCPCR);
/* Enable RXD and TXD pin functions */
ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
if (to_sci_port(port)->has_rtscts) {
/* RTS# is output, active low, unless autorts */
if (!(port->mctrl & TIOCM_RTS)) {
ctrl |= SCPCR_RTSC;
data |= SCPDR_RTSD;
} else if (!s->autorts) {
ctrl |= SCPCR_RTSC;
data &= ~SCPDR_RTSD;
} else {
/* Enable RTS# pin function */
ctrl &= ~SCPCR_RTSC;
}
/* Enable CTS# pin function */
ctrl &= ~SCPCR_CTSC;
}
sci_serial_out(port, SCPDR, data);
sci_serial_out(port, SCPCR, ctrl);
} else if (sci_getreg(port, SCSPTR)->size) {
u16 status = sci_serial_in(port, SCSPTR);
/* RTS# is always output; and active low, unless autorts */
status |= SCSPTR_RTSIO;
if (!(port->mctrl & TIOCM_RTS))
status |= SCSPTR_RTSDT;
else if (!s->autorts)
status &= ~SCSPTR_RTSDT;
/* CTS# and SCK are inputs */
status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
sci_serial_out(port, SCSPTR, status);
}
}
static int sci_txfill(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
const struct plat_sci_reg *reg;
reg = sci_getreg(port, SCTFDR);
if (reg->size)
return sci_serial_in(port, SCTFDR) & fifo_mask;
reg = sci_getreg(port, SCFDR);
if (reg->size)
return sci_serial_in(port, SCFDR) >> 8;
return !(sci_serial_in(port, SCxSR) & SCI_TDRE);
}
static int sci_txroom(struct uart_port *port)
{
return port->fifosize - sci_txfill(port);
}
static int sci_rxfill(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
const struct plat_sci_reg *reg;
reg = sci_getreg(port, SCRFDR);
if (reg->size)
return sci_serial_in(port, SCRFDR) & fifo_mask;
reg = sci_getreg(port, SCFDR);
if (reg->size)
return sci_serial_in(port, SCFDR) & fifo_mask;
return (sci_serial_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
}
/* ********************************************************************** *
* the interrupt related routines *
* ********************************************************************** */
static void sci_transmit_chars(struct uart_port *port)
{
struct tty_port *tport = &port->state->port;
unsigned int stopped = uart_tx_stopped(port);
unsigned short status;
unsigned short ctrl;
int count;
status = sci_serial_in(port, SCxSR);
if (!(status & SCxSR_TDxE(port))) {
ctrl = sci_serial_in(port, SCSCR);
if (kfifo_is_empty(&tport->xmit_fifo))
ctrl &= ~SCSCR_TIE;
else
ctrl |= SCSCR_TIE;
sci_serial_out(port, SCSCR, ctrl);
return;
}
count = sci_txroom(port);
do {
unsigned char c;
if (port->x_char) {
c = port->x_char;
port->x_char = 0;
} else if (stopped || !kfifo_get(&tport->xmit_fifo, &c)) {
if (port->type == PORT_SCI &&
kfifo_is_empty(&tport->xmit_fifo)) {
ctrl = sci_serial_in(port, SCSCR);
ctrl &= ~SCSCR_TE;
sci_serial_out(port, SCSCR, ctrl);
return;
}
break;
}
sci_serial_out(port, SCxTDR, c);
port->icount.tx++;
} while (--count > 0);
sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (kfifo_is_empty(&tport->xmit_fifo)) {
if (port->type == PORT_SCI) {
ctrl = sci_serial_in(port, SCSCR);
ctrl &= ~SCSCR_TIE;
ctrl |= SCSCR_TEIE;
sci_serial_out(port, SCSCR, ctrl);
}
sci_stop_tx(port);
}
}
static void sci_receive_chars(struct uart_port *port)
{
struct tty_port *tport = &port->state->port;
int i, count, copied = 0;
unsigned short status;
unsigned char flag;
status = sci_serial_in(port, SCxSR);
if (!(status & SCxSR_RDxF(port)))
return;
while (1) {
/* Don't copy more bytes than there is room for in the buffer */
count = tty_buffer_request_room(tport, sci_rxfill(port));
/* If for any reason we can't copy more data, we're done! */
if (count == 0)
break;
if (port->type == PORT_SCI) {
char c = sci_serial_in(port, SCxRDR);
if (uart_handle_sysrq_char(port, c))
count = 0;
else
tty_insert_flip_char(tport, c, TTY_NORMAL);
} else {
for (i = 0; i < count; i++) {
char c;
if (port->type == PORT_SCIF ||
port->type == PORT_HSCIF) {
status = sci_serial_in(port, SCxSR);
c = sci_serial_in(port, SCxRDR);
} else {
c = sci_serial_in(port, SCxRDR);
status = sci_serial_in(port, SCxSR);
}
if (uart_handle_sysrq_char(port, c)) {
count--; i--;
continue;
}
/* Store data and status */
if (status & SCxSR_FER(port)) {
flag = TTY_FRAME;
port->icount.frame++;
} else if (status & SCxSR_PER(port)) {
flag = TTY_PARITY;
port->icount.parity++;
} else
flag = TTY_NORMAL;
tty_insert_flip_char(tport, c, flag);
}
}
sci_serial_in(port, SCxSR); /* dummy read */
sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
copied += count;
port->icount.rx += count;
}
if (copied) {
/* Tell the rest of the system the news. New characters! */
tty_flip_buffer_push(tport);
} else {
/* TTY buffers full; read from RX reg to prevent lockup */
sci_serial_in(port, SCxRDR);
sci_serial_in(port, SCxSR); /* dummy read */
sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
}
}
static int sci_handle_errors(struct uart_port *port)
{
int copied = 0;
unsigned short status = sci_serial_in(port, SCxSR);
struct tty_port *tport = &port->state->port;
struct sci_port *s = to_sci_port(port);
/* Handle overruns */
if (status & s->params->overrun_mask) {
port->icount.overrun++;
/* overrun error */
if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
copied++;
}
if (status & SCxSR_FER(port)) {
/* frame error */
port->icount.frame++;
if (tty_insert_flip_char(tport, 0, TTY_FRAME))
copied++;
}
if (status & SCxSR_PER(port)) {
/* parity error */
port->icount.parity++;
if (tty_insert_flip_char(tport, 0, TTY_PARITY))
copied++;
}
if (copied)
tty_flip_buffer_push(tport);
return copied;
}
static int sci_handle_fifo_overrun(struct uart_port *port)
{
struct tty_port *tport = &port->state->port;
struct sci_port *s = to_sci_port(port);
const struct plat_sci_reg *reg;
int copied = 0;
u16 status;
reg = sci_getreg(port, s->params->overrun_reg);
if (!reg->size)
return 0;
status = sci_serial_in(port, s->params->overrun_reg);
if (status & s->params->overrun_mask) {
status &= ~s->params->overrun_mask;
sci_serial_out(port, s->params->overrun_reg, status);
port->icount.overrun++;
tty_insert_flip_char(tport, 0, TTY_OVERRUN);
tty_flip_buffer_push(tport);
copied++;
}
return copied;
}
static int sci_handle_breaks(struct uart_port *port)
{
int copied = 0;
unsigned short status = sci_serial_in(port, SCxSR);
struct tty_port *tport = &port->state->port;
if (uart_handle_break(port))
return 0;
if (status & SCxSR_BRK(port)) {
port->icount.brk++;
/* Notify of BREAK */
if (tty_insert_flip_char(tport, 0, TTY_BREAK))
copied++;
}
if (copied)
tty_flip_buffer_push(tport);
copied += sci_handle_fifo_overrun(port);
return copied;
}
static int scif_set_rtrg(struct uart_port *port, int rx_trig)
{
unsigned int bits;
if (rx_trig >= port->fifosize)
rx_trig = port->fifosize - 1;
if (rx_trig < 1)
rx_trig = 1;
/* HSCIF can be set to an arbitrary level. */
if (sci_getreg(port, HSRTRGR)->size) {
sci_serial_out(port, HSRTRGR, rx_trig);
return rx_trig;
}
switch (port->type) {
case PORT_SCIF:
if (rx_trig < 4) {
bits = 0;
rx_trig = 1;
} else if (rx_trig < 8) {
bits = SCFCR_RTRG0;
rx_trig = 4;
} else if (rx_trig < 14) {
bits = SCFCR_RTRG1;
rx_trig = 8;
} else {
bits = SCFCR_RTRG0 | SCFCR_RTRG1;
rx_trig = 14;
}
break;
case PORT_SCIFA:
case PORT_SCIFB:
if (rx_trig < 16) {
bits = 0;
rx_trig = 1;
} else if (rx_trig < 32) {
bits = SCFCR_RTRG0;
rx_trig = 16;
} else if (rx_trig < 48) {
bits = SCFCR_RTRG1;
rx_trig = 32;
} else {
bits = SCFCR_RTRG0 | SCFCR_RTRG1;
rx_trig = 48;
}
break;
default:
WARN(1, "unknown FIFO configuration");
return 1;
}
sci_serial_out(port, SCFCR,
(sci_serial_in(port, SCFCR) &
~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
return rx_trig;
}
static int scif_rtrg_enabled(struct uart_port *port)
{
if (sci_getreg(port, HSRTRGR)->size)
return sci_serial_in(port, HSRTRGR) != 0;
else
return (sci_serial_in(port, SCFCR) &
(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
}
static void rx_fifo_timer_fn(struct timer_list *t)
{
struct sci_port *s = from_timer(s, t, rx_fifo_timer);
struct uart_port *port = &s->port;
dev_dbg(port->dev, "Rx timed out\n");
scif_set_rtrg(port, 1);
}
static ssize_t rx_fifo_trigger_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct uart_port *port = dev_get_drvdata(dev);
struct sci_port *sci = to_sci_port(port);
return sprintf(buf, "%d\n", sci->rx_trigger);
}
static ssize_t rx_fifo_trigger_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct uart_port *port = dev_get_drvdata(dev);
struct sci_port *sci = to_sci_port(port);
int ret;
long r;
ret = kstrtol(buf, 0, &r);
if (ret)
return ret;
sci->rx_trigger = scif_set_rtrg(port, r);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
scif_set_rtrg(port, 1);
return count;
}
static DEVICE_ATTR_RW(rx_fifo_trigger);
static ssize_t rx_fifo_timeout_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct uart_port *port = dev_get_drvdata(dev);
struct sci_port *sci = to_sci_port(port);
int v;
if (port->type == PORT_HSCIF)
v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
else
v = sci->rx_fifo_timeout;
return sprintf(buf, "%d\n", v);
}
static ssize_t rx_fifo_timeout_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
struct uart_port *port = dev_get_drvdata(dev);
struct sci_port *sci = to_sci_port(port);
int ret;
long r;
ret = kstrtol(buf, 0, &r);
if (ret)
return ret;
if (port->type == PORT_HSCIF) {
if (r < 0 || r > 3)
return -EINVAL;
sci->hscif_tot = r << HSSCR_TOT_SHIFT;
} else {
sci->rx_fifo_timeout = r;
scif_set_rtrg(port, 1);
if (r > 0)
timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
}
return count;
}
static DEVICE_ATTR_RW(rx_fifo_timeout);
#ifdef CONFIG_SERIAL_SH_SCI_DMA
static void sci_dma_tx_complete(void *arg)
{
struct sci_port *s = arg;
struct uart_port *port = &s->port;
struct tty_port *tport = &port->state->port;
unsigned long flags;
dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
uart_port_lock_irqsave(port, &flags);
uart_xmit_advance(port, s->tx_dma_len);
if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (!kfifo_is_empty(&tport->xmit_fifo)) {
s->cookie_tx = 0;
schedule_work(&s->work_tx);
} else {
s->cookie_tx = -EINVAL;
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
u16 ctrl = sci_serial_in(port, SCSCR);
sci_serial_out(port, SCSCR, ctrl & ~SCSCR_TIE);
if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
/* Switch irq from DMA to SCIF */
dmaengine_pause(s->chan_tx_saved);
enable_irq(s->irqs[SCIx_TXI_IRQ]);
}
}
}
uart_port_unlock_irqrestore(port, flags);
}
/* Locking: called with port lock held */
static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
{
struct uart_port *port = &s->port;
struct tty_port *tport = &port->state->port;
int copied;
copied = tty_insert_flip_string(tport, buf, count);
if (copied < count)
port->icount.buf_overrun++;
port->icount.rx += copied;
return copied;
}
static int sci_dma_rx_find_active(struct sci_port *s)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
if (s->active_rx == s->cookie_rx[i])
return i;
return -1;
}
/* Must only be called with uart_port_lock taken */
static void sci_dma_rx_chan_invalidate(struct sci_port *s)
{
unsigned int i;
s->chan_rx = NULL;
for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
s->cookie_rx[i] = -EINVAL;
s->active_rx = 0;
}
static void sci_dma_rx_release(struct sci_port *s)
{
struct dma_chan *chan = s->chan_rx_saved;
struct uart_port *port = &s->port;
unsigned long flags;
uart_port_lock_irqsave(port, &flags);
s->chan_rx_saved = NULL;
sci_dma_rx_chan_invalidate(s);
uart_port_unlock_irqrestore(port, flags);
dmaengine_terminate_sync(chan);
dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
sg_dma_address(&s->sg_rx[0]));
dma_release_channel(chan);
}
static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
{
long sec = usec / 1000000;
long nsec = (usec % 1000000) * 1000;
ktime_t t = ktime_set(sec, nsec);
hrtimer_start(hrt, t, HRTIMER_MODE_REL);
}
static void sci_dma_rx_reenable_irq(struct sci_port *s)
{
struct uart_port *port = &s->port;
u16 scr;
/* Direct new serial port interrupts back to CPU */
scr = sci_serial_in(port, SCSCR);
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
enable_irq(s->irqs[SCIx_RXI_IRQ]);
if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
scif_set_rtrg(port, s->rx_trigger);
else
scr &= ~SCSCR_RDRQE;
}
sci_serial_out(port, SCSCR, scr | SCSCR_RIE);
}
static void sci_dma_rx_complete(void *arg)
{
struct sci_port *s = arg;
struct dma_chan *chan = s->chan_rx;
struct uart_port *port = &s->port;
struct dma_async_tx_descriptor *desc;
unsigned long flags;
int active, count = 0;
dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
s->active_rx);
hrtimer_cancel(&s->rx_timer);
uart_port_lock_irqsave(port, &flags);
active = sci_dma_rx_find_active(s);
if (active >= 0)
count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
if (count)
tty_flip_buffer_push(&port->state->port);
desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc)
goto fail;
desc->callback = sci_dma_rx_complete;
desc->callback_param = s;
s->cookie_rx[active] = dmaengine_submit(desc);
if (dma_submit_error(s->cookie_rx[active]))
goto fail;
s->active_rx = s->cookie_rx[!active];
dma_async_issue_pending(chan);
uart_port_unlock_irqrestore(port, flags);
dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
__func__, s->cookie_rx[active], active, s->active_rx);
start_hrtimer_us(&s->rx_timer, s->rx_timeout);
return;
fail:
/* Switch to PIO */
dmaengine_terminate_async(chan);
sci_dma_rx_chan_invalidate(s);
sci_dma_rx_reenable_irq(s);
uart_port_unlock_irqrestore(port, flags);
dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
}
static void sci_dma_tx_release(struct sci_port *s)
{
struct dma_chan *chan = s->chan_tx_saved;
cancel_work_sync(&s->work_tx);
s->chan_tx_saved = s->chan_tx = NULL;
s->cookie_tx = -EINVAL;
dmaengine_terminate_sync(chan);
dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
DMA_TO_DEVICE);
dma_release_channel(chan);
}
static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
{
struct dma_chan *chan = s->chan_rx;
struct uart_port *port = &s->port;
unsigned long flags;
int i;
for (i = 0; i < 2; i++) {
struct scatterlist *sg = &s->sg_rx[i];
struct dma_async_tx_descriptor *desc;
desc = dmaengine_prep_slave_sg(chan,
sg, 1, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc)
goto fail;
desc->callback = sci_dma_rx_complete;
desc->callback_param = s;
s->cookie_rx[i] = dmaengine_submit(desc);
if (dma_submit_error(s->cookie_rx[i]))
goto fail;
}
s->active_rx = s->cookie_rx[0];
dma_async_issue_pending(chan);
return 0;
fail:
/* Switch to PIO */
if (!port_lock_held)
uart_port_lock_irqsave(port, &flags);
if (i)
dmaengine_terminate_async(chan);
sci_dma_rx_chan_invalidate(s);
sci_start_rx(port);
if (!port_lock_held)
uart_port_unlock_irqrestore(port, flags);
return -EAGAIN;
}
static void sci_dma_tx_work_fn(struct work_struct *work)
{
struct sci_port *s = container_of(work, struct sci_port, work_tx);
struct dma_async_tx_descriptor *desc;
struct dma_chan *chan = s->chan_tx;
struct uart_port *port = &s->port;
struct tty_port *tport = &port->state->port;
unsigned long flags;
unsigned int tail;
dma_addr_t buf;
/*
* DMA is idle now.
* Port xmit buffer is already mapped, and it is one page... Just adjust
* offsets and lengths. Since it is a circular buffer, we have to
* transmit till the end, and then the rest. Take the port lock to get a
* consistent xmit buffer state.
*/
uart_port_lock_irq(port);
s->tx_dma_len = kfifo_out_linear(&tport->xmit_fifo, &tail,
UART_XMIT_SIZE);
buf = s->tx_dma_addr + tail;
if (!s->tx_dma_len) {
/* Transmit buffer has been flushed */
uart_port_unlock_irq(port);
return;
}
desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
uart_port_unlock_irq(port);
dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
goto switch_to_pio;
}
dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
DMA_TO_DEVICE);
desc->callback = sci_dma_tx_complete;
desc->callback_param = s;
s->cookie_tx = dmaengine_submit(desc);
if (dma_submit_error(s->cookie_tx)) {
uart_port_unlock_irq(port);
dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
goto switch_to_pio;
}
uart_port_unlock_irq(port);
dev_dbg(port->dev, "%s: %p: %u, cookie %d\n",
__func__, tport->xmit_buf, tail, s->cookie_tx);
dma_async_issue_pending(chan);
return;
switch_to_pio:
uart_port_lock_irqsave(port, &flags);
s->chan_tx = NULL;
sci_start_tx(port);
uart_port_unlock_irqrestore(port, flags);
return;
}
static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
{
struct sci_port *s = container_of(t, struct sci_port, rx_timer);
struct dma_chan *chan = s->chan_rx;
struct uart_port *port = &s->port;
struct dma_tx_state state;
enum dma_status status;
unsigned long flags;
unsigned int read;
int active, count;
dev_dbg(port->dev, "DMA Rx timed out\n");
uart_port_lock_irqsave(port, &flags);
active = sci_dma_rx_find_active(s);
if (active < 0) {
uart_port_unlock_irqrestore(port, flags);
return HRTIMER_NORESTART;
}
status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
if (status == DMA_COMPLETE) {
uart_port_unlock_irqrestore(port, flags);
dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
s->active_rx, active);
/* Let packet complete handler take care of the packet */
return HRTIMER_NORESTART;
}
dmaengine_pause(chan);
/*
* sometimes DMA transfer doesn't stop even if it is stopped and
* data keeps on coming until transaction is complete so check
* for DMA_COMPLETE again
* Let packet complete handler take care of the packet
*/
status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
if (status == DMA_COMPLETE) {
uart_port_unlock_irqrestore(port, flags);
dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
return HRTIMER_NORESTART;
}
/* Handle incomplete DMA receive */
dmaengine_terminate_async(s->chan_rx);
read = sg_dma_len(&s->sg_rx[active]) - state.residue;
if (read) {
count = sci_dma_rx_push(s, s->rx_buf[active], read);
if (count)
tty_flip_buffer_push(&port->state->port);
}
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
sci_dma_rx_submit(s, true);
sci_dma_rx_reenable_irq(s);
uart_port_unlock_irqrestore(port, flags);
return HRTIMER_NORESTART;
}
static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
enum dma_transfer_direction dir)
{
struct dma_chan *chan;
struct dma_slave_config cfg;
int ret;
chan = dma_request_chan(port->dev, dir == DMA_MEM_TO_DEV ? "tx" : "rx");
if (IS_ERR(chan)) {
dev_dbg(port->dev, "dma_request_chan failed\n");
return NULL;
}
memset(&cfg, 0, sizeof(cfg));
cfg.direction = dir;
cfg.dst_addr = port->mapbase +
(sci_getreg(port, SCxTDR)->offset << port->regshift);
cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
cfg.src_addr = port->mapbase +
(sci_getreg(port, SCxRDR)->offset << port->regshift);
cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
ret = dmaengine_slave_config(chan, &cfg);
if (ret) {
dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
dma_release_channel(chan);
return NULL;
}
return chan;
}
static void sci_request_dma(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
struct tty_port *tport = &port->state->port;
struct dma_chan *chan;
dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
/*
* DMA on console may interfere with Kernel log messages which use
* plain putchar(). So, simply don't use it with a console.
*/
if (uart_console(port))
return;
if (!port->dev->of_node)
return;
s->cookie_tx = -EINVAL;
/*
* Don't request a dma channel if no channel was specified
* in the device tree.
*/
if (!of_property_present(port->dev->of_node, "dmas"))
return;
chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
if (chan) {
/* UART circular tx buffer is an aligned page. */
s->tx_dma_addr = dma_map_single(chan->device->dev,
tport->xmit_buf,
UART_XMIT_SIZE,
DMA_TO_DEVICE);
if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
dma_release_channel(chan);
} else {
dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
__func__, UART_XMIT_SIZE,
tport->xmit_buf, &s->tx_dma_addr);
INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
s->chan_tx_saved = s->chan_tx = chan;
}
}
chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
if (chan) {
unsigned int i;
dma_addr_t dma;
void *buf;
s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
&dma, GFP_KERNEL);
if (!buf) {
dev_warn(port->dev,
"Failed to allocate Rx dma buffer, using PIO\n");
dma_release_channel(chan);
return;
}
for (i = 0; i < 2; i++) {
struct scatterlist *sg = &s->sg_rx[i];
sg_init_table(sg, 1);
s->rx_buf[i] = buf;
sg_dma_address(sg) = dma;
sg_dma_len(sg) = s->buf_len_rx;
buf += s->buf_len_rx;
dma += s->buf_len_rx;
}
hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
s->rx_timer.function = sci_dma_rx_timer_fn;
s->chan_rx_saved = s->chan_rx = chan;
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
sci_dma_rx_submit(s, false);
}
}
static void sci_free_dma(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
if (s->chan_tx_saved)
sci_dma_tx_release(s);
if (s->chan_rx_saved)
sci_dma_rx_release(s);
}
static void sci_flush_buffer(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
/*
* In uart_flush_buffer(), the xmit circular buffer has just been
* cleared, so we have to reset tx_dma_len accordingly, and stop any
* pending transfers
*/
s->tx_dma_len = 0;
if (s->chan_tx) {
dmaengine_terminate_async(s->chan_tx);
s->cookie_tx = -EINVAL;
}
}
#else /* !CONFIG_SERIAL_SH_SCI_DMA */
static inline void sci_request_dma(struct uart_port *port)
{
}
static inline void sci_free_dma(struct uart_port *port)
{
}
#define sci_flush_buffer NULL
#endif /* !CONFIG_SERIAL_SH_SCI_DMA */
static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
struct sci_port *s = to_sci_port(port);
#ifdef CONFIG_SERIAL_SH_SCI_DMA
if (s->chan_rx) {
u16 scr = sci_serial_in(port, SCSCR);
u16 ssr = sci_serial_in(port, SCxSR);
/* Disable future Rx interrupts */
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
disable_irq_nosync(s->irqs[SCIx_RXI_IRQ]);
if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
scif_set_rtrg(port, 1);
scr |= SCSCR_RIE;
} else {
scr |= SCSCR_RDRQE;
}
} else {
if (sci_dma_rx_submit(s, false) < 0)
goto handle_pio;
scr &= ~SCSCR_RIE;
}
sci_serial_out(port, SCSCR, scr);
/* Clear current interrupt */
sci_serial_out(port, SCxSR,
ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
jiffies, s->rx_timeout);
start_hrtimer_us(&s->rx_timer, s->rx_timeout);
return IRQ_HANDLED;
}
handle_pio:
#endif
if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
if (!scif_rtrg_enabled(port))
scif_set_rtrg(port, s->rx_trigger);
mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
}
/* I think sci_receive_chars has to be called irrespective
* of whether the I_IXOFF is set, otherwise, how is the interrupt
* to be disabled?
*/
sci_receive_chars(port);
return IRQ_HANDLED;
}
static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
unsigned long flags;
uart_port_lock_irqsave(port, &flags);
sci_transmit_chars(port);
uart_port_unlock_irqrestore(port, flags);
return IRQ_HANDLED;
}
static irqreturn_t sci_tx_end_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
unsigned long flags;
unsigned short ctrl;
if (port->type != PORT_SCI)
return sci_tx_interrupt(irq, ptr);
uart_port_lock_irqsave(port, &flags);
ctrl = sci_serial_in(port, SCSCR);
ctrl &= ~(SCSCR_TE | SCSCR_TEIE);
sci_serial_out(port, SCSCR, ctrl);
uart_port_unlock_irqrestore(port, flags);
return IRQ_HANDLED;
}
static irqreturn_t sci_br_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
/* Handle BREAKs */
sci_handle_breaks(port);
/* drop invalid character received before break was detected */
sci_serial_in(port, SCxRDR);
sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
return IRQ_HANDLED;
}
static irqreturn_t sci_er_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
struct sci_port *s = to_sci_port(port);
if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
/* Break and Error interrupts are muxed */
unsigned short ssr_status = sci_serial_in(port, SCxSR);
/* Break Interrupt */
if (ssr_status & SCxSR_BRK(port))
sci_br_interrupt(irq, ptr);
/* Break only? */
if (!(ssr_status & SCxSR_ERRORS(port)))
return IRQ_HANDLED;
}
/* Handle errors */
if (port->type == PORT_SCI) {
if (sci_handle_errors(port)) {
/* discard character in rx buffer */
sci_serial_in(port, SCxSR);
sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
}
} else {
sci_handle_fifo_overrun(port);
if (!s->chan_rx)
sci_receive_chars(port);
}
sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
/* Kick the transmission */
if (!s->chan_tx)
sci_tx_interrupt(irq, ptr);
return IRQ_HANDLED;
}
static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
{
unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
struct uart_port *port = ptr;
struct sci_port *s = to_sci_port(port);
irqreturn_t ret = IRQ_NONE;
ssr_status = sci_serial_in(port, SCxSR);
scr_status = sci_serial_in(port, SCSCR);
if (s->params->overrun_reg == SCxSR)
orer_status = ssr_status;
else if (sci_getreg(port, s->params->overrun_reg)->size)
orer_status = sci_serial_in(port, s->params->overrun_reg);
err_enabled = scr_status & port_rx_irq_mask(port);
/* Tx Interrupt */
if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
!s->chan_tx)
ret = sci_tx_interrupt(irq, ptr);
/*
* Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
* DR flags
*/
if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
(scr_status & SCSCR_RIE))
ret = sci_rx_interrupt(irq, ptr);
/* Error Interrupt */
if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
ret = sci_er_interrupt(irq, ptr);
/* Break Interrupt */
if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
(ssr_status & SCxSR_BRK(port)) && err_enabled)
ret = sci_br_interrupt(irq, ptr);
/* Overrun Interrupt */
if (orer_status & s->params->overrun_mask) {
sci_handle_fifo_overrun(port);
ret = IRQ_HANDLED;
}
return ret;
}
static const struct sci_irq_desc {
const char *desc;
irq_handler_t handler;
} sci_irq_desc[] = {
/*
* Split out handlers, the default case.
*/
[SCIx_ERI_IRQ] = {
.desc = "rx err",
.handler = sci_er_interrupt,
},
[SCIx_RXI_IRQ] = {
.desc = "rx full",
.handler = sci_rx_interrupt,
},
[SCIx_TXI_IRQ] = {
.desc = "tx empty",
.handler = sci_tx_interrupt,
},
[SCIx_BRI_IRQ] = {
.desc = "break",
.handler = sci_br_interrupt,
},
[SCIx_DRI_IRQ] = {
.desc = "rx ready",
.handler = sci_rx_interrupt,
},
[SCIx_TEI_IRQ] = {
.desc = "tx end",
.handler = sci_tx_end_interrupt,
},
/*
* Special muxed handler.
*/
[SCIx_MUX_IRQ] = {
.desc = "mux",
.handler = sci_mpxed_interrupt,
},
};
static int sci_request_irq(struct sci_port *port)
{
struct uart_port *up = &port->port;
int i, j, w, ret = 0;
for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
const struct sci_irq_desc *desc;
int irq;
/* Check if already registered (muxed) */
for (w = 0; w < i; w++)
if (port->irqs[w] == port->irqs[i])
w = i + 1;
if (w > i)
continue;
if (SCIx_IRQ_IS_MUXED(port)) {
i = SCIx_MUX_IRQ;
irq = up->irq;
} else {
irq = port->irqs[i];
/*
* Certain port types won't support all of the
* available interrupt sources.
*/
if (unlikely(irq < 0))
continue;
}
desc = sci_irq_desc + i;
port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
dev_name(up->dev), desc->desc);
if (!port->irqstr[j]) {
ret = -ENOMEM;
goto out_nomem;
}
ret = request_irq(irq, desc->handler, up->irqflags,
port->irqstr[j], port);
if (unlikely(ret)) {
dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
goto out_noirq;
}
}
return 0;
out_noirq:
while (--i >= 0)
free_irq(port->irqs[i], port);
out_nomem:
while (--j >= 0)
kfree(port->irqstr[j]);
return ret;
}
static void sci_free_irq(struct sci_port *port)
{
int i, j;
/*
* Intentionally in reverse order so we iterate over the muxed
* IRQ first.
*/
for (i = 0; i < SCIx_NR_IRQS; i++) {
int irq = port->irqs[i];
/*
* Certain port types won't support all of the available
* interrupt sources.
*/
if (unlikely(irq < 0))
continue;
/* Check if already freed (irq was muxed) */
for (j = 0; j < i; j++)
if (port->irqs[j] == irq)
j = i + 1;
if (j > i)
continue;
free_irq(port->irqs[i], port);
kfree(port->irqstr[i]);
if (SCIx_IRQ_IS_MUXED(port)) {
/* If there's only one IRQ, we're done. */
return;
}
}
}
static unsigned int sci_tx_empty(struct uart_port *port)
{
unsigned short status = sci_serial_in(port, SCxSR);
unsigned short in_tx_fifo = sci_txfill(port);
return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
}
static void sci_set_rts(struct uart_port *port, bool state)
{
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
u16 data = sci_serial_in(port, SCPDR);
/* Active low */
if (state)
data &= ~SCPDR_RTSD;
else
data |= SCPDR_RTSD;
sci_serial_out(port, SCPDR, data);
/* RTS# is output */
sci_serial_out(port, SCPCR,
sci_serial_in(port, SCPCR) | SCPCR_RTSC);
} else if (sci_getreg(port, SCSPTR)->size) {
u16 ctrl = sci_serial_in(port, SCSPTR);
/* Active low */
if (state)
ctrl &= ~SCSPTR_RTSDT;
else
ctrl |= SCSPTR_RTSDT;
sci_serial_out(port, SCSPTR, ctrl);
}
}
static bool sci_get_cts(struct uart_port *port)
{
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
/* Active low */
return !(sci_serial_in(port, SCPDR) & SCPDR_CTSD);
} else if (sci_getreg(port, SCSPTR)->size) {
/* Active low */
return !(sci_serial_in(port, SCSPTR) & SCSPTR_CTSDT);
}
return true;
}
/*
* Modem control is a bit of a mixed bag for SCI(F) ports. Generally
* CTS/RTS is supported in hardware by at least one port and controlled
* via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
* handled via the ->init_pins() op, which is a bit of a one-way street,
* lacking any ability to defer pin control -- this will later be
* converted over to the GPIO framework).
*
* Other modes (such as loopback) are supported generically on certain
* port types, but not others. For these it's sufficient to test for the
* existence of the support register and simply ignore the port type.
*/
static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct sci_port *s = to_sci_port(port);
if (mctrl & TIOCM_LOOP) {
const struct plat_sci_reg *reg;
/*
* Standard loopback mode for SCFCR ports.
*/
reg = sci_getreg(port, SCFCR);
if (reg->size)
sci_serial_out(port, SCFCR,
sci_serial_in(port, SCFCR) | SCFCR_LOOP);
}
mctrl_gpio_set(s->gpios, mctrl);
if (!s->has_rtscts)
return;
if (!(mctrl & TIOCM_RTS)) {
/* Disable Auto RTS */
sci_serial_out(port, SCFCR,
sci_serial_in(port, SCFCR) & ~SCFCR_MCE);
/* Clear RTS */
sci_set_rts(port, 0);
} else if (s->autorts) {
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
/* Enable RTS# pin function */
sci_serial_out(port, SCPCR,
sci_serial_in(port, SCPCR) & ~SCPCR_RTSC);
}
/* Enable Auto RTS */
sci_serial_out(port, SCFCR,
sci_serial_in(port, SCFCR) | SCFCR_MCE);
} else {
/* Set RTS */
sci_set_rts(port, 1);
}
}
static unsigned int sci_get_mctrl(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
struct mctrl_gpios *gpios = s->gpios;
unsigned int mctrl = 0;
mctrl_gpio_get(gpios, &mctrl);
/*
* CTS/RTS is handled in hardware when supported, while nothing
* else is wired up.
*/
if (s->autorts) {
if (sci_get_cts(port))
mctrl |= TIOCM_CTS;
} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
mctrl |= TIOCM_CTS;
}
if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
mctrl |= TIOCM_DSR;
if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
mctrl |= TIOCM_CAR;
return mctrl;
}
static void sci_enable_ms(struct uart_port *port)
{
mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
}
static void sci_break_ctl(struct uart_port *port, int break_state)
{
unsigned short scscr, scsptr;
unsigned long flags;
/* check whether the port has SCSPTR */
if (!sci_getreg(port, SCSPTR)->size) {
/*
* Not supported by hardware. Most parts couple break and rx
* interrupts together, with break detection always enabled.
*/
return;
}
uart_port_lock_irqsave(port, &flags);
scsptr = sci_serial_in(port, SCSPTR);
scscr = sci_serial_in(port, SCSCR);
if (break_state == -1) {
scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
scscr &= ~SCSCR_TE;
} else {
scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
scscr |= SCSCR_TE;
}
sci_serial_out(port, SCSPTR, scsptr);
sci_serial_out(port, SCSCR, scscr);
uart_port_unlock_irqrestore(port, flags);
}
static int sci_startup(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
int ret;
dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
sci_request_dma(port);
ret = sci_request_irq(s);
if (unlikely(ret < 0)) {
sci_free_dma(port);
return ret;
}
return 0;
}
static void sci_shutdown(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
unsigned long flags;
u16 scr;
dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
s->autorts = false;
mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
uart_port_lock_irqsave(port, &flags);
sci_stop_rx(port);
sci_stop_tx(port);
/*
* Stop RX and TX, disable related interrupts, keep clock source
* and HSCIF TOT bits
*/
scr = sci_serial_in(port, SCSCR);
sci_serial_out(port, SCSCR,
scr & (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
uart_port_unlock_irqrestore(port, flags);
#ifdef CONFIG_SERIAL_SH_SCI_DMA
if (s->chan_rx_saved) {
dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
port->line);
hrtimer_cancel(&s->rx_timer);
}
#endif
if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
del_timer_sync(&s->rx_fifo_timer);
sci_free_irq(s);
sci_free_dma(port);
}
static int sci_sck_calc(struct sci_port *s, unsigned int bps,
unsigned int *srr)
{
unsigned long freq = s->clk_rates[SCI_SCK];
int err, min_err = INT_MAX;
unsigned int sr;
if (s->port.type != PORT_HSCIF)
freq *= 2;
for_each_sr(sr, s) {
err = DIV_ROUND_CLOSEST(freq, sr) - bps;
if (abs(err) >= abs(min_err))
continue;
min_err = err;
*srr = sr - 1;
if (!err)
break;
}
dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
*srr + 1);
return min_err;
}
static int sci_brg_calc(struct sci_port *s, unsigned int bps,
unsigned long freq, unsigned int *dlr,
unsigned int *srr)
{
int err, min_err = INT_MAX;
unsigned int sr, dl;
if (s->port.type != PORT_HSCIF)
freq *= 2;
for_each_sr(sr, s) {
dl = DIV_ROUND_CLOSEST(freq, sr * bps);
dl = clamp(dl, 1U, 65535U);
err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
if (abs(err) >= abs(min_err))
continue;
min_err = err;
*dlr = dl;
*srr = sr - 1;
if (!err)
break;
}
dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
min_err, *dlr, *srr + 1);
return min_err;
}
/* calculate sample rate, BRR, and clock select */
static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
unsigned int *brr, unsigned int *srr,
unsigned int *cks)
{
unsigned long freq = s->clk_rates[SCI_FCK];
unsigned int sr, br, prediv, scrate, c;
int err, min_err = INT_MAX;
if (s->port.type != PORT_HSCIF)
freq *= 2;
/*
* Find the combination of sample rate and clock select with the
* smallest deviation from the desired baud rate.
* Prefer high sample rates to maximise the receive margin.
*
* M: Receive margin (%)
* N: Ratio of bit rate to clock (N = sampling rate)
* D: Clock duty (D = 0 to 1.0)
* L: Frame length (L = 9 to 12)
* F: Absolute value of clock frequency deviation
*
* M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
* (|D - 0.5| / N * (1 + F))|
* NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
*/
for_each_sr(sr, s) {
for (c = 0; c <= 3; c++) {
/* integerized formulas from HSCIF documentation */
prediv = sr << (2 * c + 1);
/*
* We need to calculate:
*
* br = freq / (prediv * bps) clamped to [1..256]
* err = freq / (br * prediv) - bps
*
* Watch out for overflow when calculating the desired
* sampling clock rate!
*/
if (bps > UINT_MAX / prediv)
break;
scrate = prediv * bps;
br = DIV_ROUND_CLOSEST(freq, scrate);
br = clamp(br, 1U, 256U);
err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
if (abs(err) >= abs(min_err))
continue;
min_err = err;
*brr = br - 1;
*srr = sr - 1;
*cks = c;
if (!err)
goto found;
}
}
found:
dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
min_err, *brr, *srr + 1, *cks);
return min_err;
}
static void sci_reset(struct uart_port *port)
{
const struct plat_sci_reg *reg;
unsigned int status;
struct sci_port *s = to_sci_port(port);
sci_serial_out(port, SCSCR, s->hscif_tot); /* TE=0, RE=0, CKE1=0 */
reg = sci_getreg(port, SCFCR);
if (reg->size)
sci_serial_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
sci_clear_SCxSR(port,
SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
SCxSR_BREAK_CLEAR(port));
if (sci_getreg(port, SCLSR)->size) {
status = sci_serial_in(port, SCLSR);
status &= ~(SCLSR_TO | SCLSR_ORER);
sci_serial_out(port, SCLSR, status);
}
if (s->rx_trigger > 1) {
if (s->rx_fifo_timeout) {
scif_set_rtrg(port, 1);
timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
} else {
if (port->type == PORT_SCIFA ||
port->type == PORT_SCIFB)
scif_set_rtrg(port, 1);
else
scif_set_rtrg(port, s->rx_trigger);
}
}
}
static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
const struct ktermios *old)
{
unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
struct sci_port *s = to_sci_port(port);
const struct plat_sci_reg *reg;
int min_err = INT_MAX, err;
unsigned long max_freq = 0;
int best_clk = -1;
unsigned long flags;
if ((termios->c_cflag & CSIZE) == CS7) {
smr_val |= SCSMR_CHR;
} else {
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= CS8;
}
if (termios->c_cflag & PARENB)
smr_val |= SCSMR_PE;
if (termios->c_cflag & PARODD)
smr_val |= SCSMR_PE | SCSMR_ODD;
if (termios->c_cflag & CSTOPB)
smr_val |= SCSMR_STOP;
/*
* earlyprintk comes here early on with port->uartclk set to zero.
* the clock framework is not up and running at this point so here
* we assume that 115200 is the maximum baud rate. please note that
* the baud rate is not programmed during earlyprintk - it is assumed
* that the previous boot loader has enabled required clocks and
* setup the baud rate generator hardware for us already.
*/
if (!port->uartclk) {
baud = uart_get_baud_rate(port, termios, old, 0, 115200);
goto done;
}
for (i = 0; i < SCI_NUM_CLKS; i++)
max_freq = max(max_freq, s->clk_rates[i]);
baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
if (!baud)
goto done;
/*
* There can be multiple sources for the sampling clock. Find the one
* that gives us the smallest deviation from the desired baud rate.
*/
/* Optional Undivided External Clock */
if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
port->type != PORT_SCIFB) {
err = sci_sck_calc(s, baud, &srr1);
if (abs(err) < abs(min_err)) {
best_clk = SCI_SCK;
scr_val = SCSCR_CKE1;
sccks = SCCKS_CKS;
min_err = err;
srr = srr1;
if (!err)
goto done;
}
}
/* Optional BRG Frequency Divided External Clock */
if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
&srr1);
if (abs(err) < abs(min_err)) {
best_clk = SCI_SCIF_CLK;
scr_val = SCSCR_CKE1;
sccks = 0;
min_err = err;
dl = dl1;
srr = srr1;
if (!err)
goto done;
}
}
/* Optional BRG Frequency Divided Internal Clock */
if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
&srr1);
if (abs(err) < abs(min_err)) {
best_clk = SCI_BRG_INT;
scr_val = SCSCR_CKE1;
sccks = SCCKS_XIN;
min_err = err;
dl = dl1;
srr = srr1;
if (!min_err)
goto done;
}
}
/* Divided Functional Clock using standard Bit Rate Register */
err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
if (abs(err) < abs(min_err)) {
best_clk = SCI_FCK;
scr_val = 0;
min_err = err;
brr = brr1;
srr = srr1;
cks = cks1;
}
done:
if (best_clk >= 0)
dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
s->clks[best_clk], baud, min_err);
sci_port_enable(s);
/*
* Program the optional External Baud Rate Generator (BRG) first.
* It controls the mux to select (H)SCK or frequency divided clock.
*/
if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
sci_serial_out(port, SCDL, dl);
sci_serial_out(port, SCCKS, sccks);
}
uart_port_lock_irqsave(port, &flags);
sci_reset(port);
uart_update_timeout(port, termios->c_cflag, baud);
/* byte size and parity */
bits = tty_get_frame_size(termios->c_cflag);
if (sci_getreg(port, SEMR)->size)
sci_serial_out(port, SEMR, 0);
if (best_clk >= 0) {
if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
switch (srr + 1) {
case 5: smr_val |= SCSMR_SRC_5; break;
case 7: smr_val |= SCSMR_SRC_7; break;
case 11: smr_val |= SCSMR_SRC_11; break;
case 13: smr_val |= SCSMR_SRC_13; break;
case 16: smr_val |= SCSMR_SRC_16; break;
case 17: smr_val |= SCSMR_SRC_17; break;
case 19: smr_val |= SCSMR_SRC_19; break;
case 27: smr_val |= SCSMR_SRC_27; break;
}
smr_val |= cks;
sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
sci_serial_out(port, SCSMR, smr_val);
sci_serial_out(port, SCBRR, brr);
if (sci_getreg(port, HSSRR)->size) {
unsigned int hssrr = srr | HSCIF_SRE;
/* Calculate deviation from intended rate at the
* center of the last stop bit in sampling clocks.
*/
int last_stop = bits * 2 - 1;
int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
(int)(srr + 1),
2 * (int)baud);
if (abs(deviation) >= 2) {
/* At least two sampling clocks off at the
* last stop bit; we can increase the error
* margin by shifting the sampling point.
*/
int shift = clamp(deviation / 2, -8, 7);
hssrr |= (shift << HSCIF_SRHP_SHIFT) &
HSCIF_SRHP_MASK;
hssrr |= HSCIF_SRDE;
}
sci_serial_out(port, HSSRR, hssrr);
}
/* Wait one bit interval */
udelay((1000000 + (baud - 1)) / baud);
} else {
/* Don't touch the bit rate configuration */
scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
smr_val |= sci_serial_in(port, SCSMR) &
(SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
sci_serial_out(port, SCSMR, smr_val);
}
sci_init_pins(port, termios->c_cflag);
port->status &= ~UPSTAT_AUTOCTS;
s->autorts = false;
reg = sci_getreg(port, SCFCR);
if (reg->size) {
unsigned short ctrl = sci_serial_in(port, SCFCR);
if ((port->flags & UPF_HARD_FLOW) &&
(termios->c_cflag & CRTSCTS)) {
/* There is no CTS interrupt to restart the hardware */
port->status |= UPSTAT_AUTOCTS;
/* MCE is enabled when RTS is raised */
s->autorts = true;
}
/*
* As we've done a sci_reset() above, ensure we don't
* interfere with the FIFOs while toggling MCE. As the
* reset values could still be set, simply mask them out.
*/
ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
sci_serial_out(port, SCFCR, ctrl);
}
if (port->flags & UPF_HARD_FLOW) {
/* Refresh (Auto) RTS */
sci_set_mctrl(port, port->mctrl);
}
/*
* For SCI, TE (transmit enable) must be set after setting TIE
* (transmit interrupt enable) or in the same instruction to
* start the transmitting process. So skip setting TE here for SCI.
*/
if (port->type != PORT_SCI)
scr_val |= SCSCR_TE;
scr_val |= SCSCR_RE | (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
sci_serial_out(port, SCSCR, scr_val | s->hscif_tot);
if ((srr + 1 == 5) &&
(port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
/*
* In asynchronous mode, when the sampling rate is 1/5, first
* received data may become invalid on some SCIFA and SCIFB.
* To avoid this problem wait more than 1 serial data time (1
* bit time x serial data number) after setting SCSCR.RE = 1.
*/
udelay(DIV_ROUND_UP(10 * 1000000, baud));
}
/* Calculate delay for 2 DMA buffers (4 FIFO). */
s->rx_frame = (10000 * bits) / (baud / 100);
#ifdef CONFIG_SERIAL_SH_SCI_DMA
s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
#endif
if ((termios->c_cflag & CREAD) != 0)
sci_start_rx(port);
uart_port_unlock_irqrestore(port, flags);
sci_port_disable(s);
if (UART_ENABLE_MS(port, termios->c_cflag))
sci_enable_ms(port);
}
static void sci_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
struct sci_port *sci_port = to_sci_port(port);
switch (state) {
case UART_PM_STATE_OFF:
sci_port_disable(sci_port);
break;
default:
sci_port_enable(sci_port);
break;
}
}
static const char *sci_type(struct uart_port *port)
{
switch (port->type) {
case PORT_IRDA:
return "irda";
case PORT_SCI:
return "sci";
case PORT_SCIF:
return "scif";
case PORT_SCIFA:
return "scifa";
case PORT_SCIFB:
return "scifb";
case PORT_HSCIF:
return "hscif";
}
return NULL;
}
static int sci_remap_port(struct uart_port *port)
{
struct sci_port *sport = to_sci_port(port);
/*
* Nothing to do if there's already an established membase.
*/
if (port->membase)
return 0;
if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
port->membase = ioremap(port->mapbase, sport->reg_size);
if (unlikely(!port->membase)) {
dev_err(port->dev, "can't remap port#%d\n", port->line);
return -ENXIO;
}
} else {
/*
* For the simple (and majority of) cases where we don't
* need to do any remapping, just cast the cookie
* directly.
*/
port->membase = (void __iomem *)(uintptr_t)port->mapbase;
}
return 0;
}
static void sci_release_port(struct uart_port *port)
{
struct sci_port *sport = to_sci_port(port);
if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
iounmap(port->membase);
port->membase = NULL;
}
release_mem_region(port->mapbase, sport->reg_size);
}
static int sci_request_port(struct uart_port *port)
{
struct resource *res;
struct sci_port *sport = to_sci_port(port);
int ret;
res = request_mem_region(port->mapbase, sport->reg_size,
dev_name(port->dev));
if (unlikely(res == NULL)) {
dev_err(port->dev, "request_mem_region failed.");
return -EBUSY;
}
ret = sci_remap_port(port);
if (unlikely(ret != 0)) {
release_resource(res);
return ret;
}
return 0;
}
static void sci_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE) {
struct sci_port *sport = to_sci_port(port);
port->type = sport->cfg->type;
sci_request_port(port);
}
}
static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
{
if (ser->baud_base < 2400)
/* No paper tape reader for Mitch.. */
return -EINVAL;
return 0;
}
static const struct uart_ops sci_uart_ops = {
.tx_empty = sci_tx_empty,
.set_mctrl = sci_set_mctrl,
.get_mctrl = sci_get_mctrl,
.start_tx = sci_start_tx,
.stop_tx = sci_stop_tx,
.stop_rx = sci_stop_rx,
.enable_ms = sci_enable_ms,
.break_ctl = sci_break_ctl,
.startup = sci_startup,
.shutdown = sci_shutdown,
.flush_buffer = sci_flush_buffer,
.set_termios = sci_set_termios,
.pm = sci_pm,
.type = sci_type,
.release_port = sci_release_port,
.request_port = sci_request_port,
.config_port = sci_config_port,
.verify_port = sci_verify_port,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = sci_poll_get_char,
.poll_put_char = sci_poll_put_char,
#endif
};
static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
{
const char *clk_names[] = {
[SCI_FCK] = "fck",
[SCI_SCK] = "sck",
[SCI_BRG_INT] = "brg_int",
[SCI_SCIF_CLK] = "scif_clk",
};
struct clk *clk;
unsigned int i;
if (sci_port->cfg->type == PORT_HSCIF)
clk_names[SCI_SCK] = "hsck";
for (i = 0; i < SCI_NUM_CLKS; i++) {
clk = devm_clk_get_optional(dev, clk_names[i]);
if (IS_ERR(clk))
return PTR_ERR(clk);
if (!clk && i == SCI_FCK) {
/*
* Not all SH platforms declare a clock lookup entry
* for SCI devices, in which case we need to get the
* global "peripheral_clk" clock.
*/
clk = devm_clk_get(dev, "peripheral_clk");
if (IS_ERR(clk))
return dev_err_probe(dev, PTR_ERR(clk),
"failed to get %s\n",
clk_names[i]);
}
if (!clk)
dev_dbg(dev, "failed to get %s\n", clk_names[i]);
else
dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
clk, clk_get_rate(clk));
sci_port->clks[i] = clk;
}
return 0;
}
static const struct sci_port_params *
sci_probe_regmap(const struct plat_sci_port *cfg)
{
unsigned int regtype;
if (cfg->regtype != SCIx_PROBE_REGTYPE)
return &sci_port_params[cfg->regtype];
switch (cfg->type) {
case PORT_SCI:
regtype = SCIx_SCI_REGTYPE;
break;
case PORT_IRDA:
regtype = SCIx_IRDA_REGTYPE;
break;
case PORT_SCIFA:
regtype = SCIx_SCIFA_REGTYPE;
break;
case PORT_SCIFB:
regtype = SCIx_SCIFB_REGTYPE;
break;
case PORT_SCIF:
/*
* The SH-4 is a bit of a misnomer here, although that's
* where this particular port layout originated. This
* configuration (or some slight variation thereof)
* remains the dominant model for all SCIFs.
*/
regtype = SCIx_SH4_SCIF_REGTYPE;
break;
case PORT_HSCIF:
regtype = SCIx_HSCIF_REGTYPE;
break;
default:
pr_err("Can't probe register map for given port\n");
return NULL;
}
return &sci_port_params[regtype];
}
static int sci_init_single(struct platform_device *dev,
struct sci_port *sci_port, unsigned int index,
const struct plat_sci_port *p, bool early)
{
struct uart_port *port = &sci_port->port;
const struct resource *res;
unsigned int i;
int ret;
sci_port->cfg = p;
port->ops = &sci_uart_ops;
port->iotype = UPIO_MEM;
port->line = index;
port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (res == NULL)
return -ENOMEM;
port->mapbase = res->start;
sci_port->reg_size = resource_size(res);
for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
if (i)
sci_port->irqs[i] = platform_get_irq_optional(dev, i);
else
sci_port->irqs[i] = platform_get_irq(dev, i);
}
/*
* The fourth interrupt on SCI port is transmit end interrupt, so
* shuffle the interrupts.
*/
if (p->type == PORT_SCI)
swap(sci_port->irqs[SCIx_BRI_IRQ], sci_port->irqs[SCIx_TEI_IRQ]);
/* The SCI generates several interrupts. They can be muxed together or
* connected to different interrupt lines. In the muxed case only one
* interrupt resource is specified as there is only one interrupt ID.
* In the non-muxed case, up to 6 interrupt signals might be generated
* from the SCI, however those signals might have their own individual
* interrupt ID numbers, or muxed together with another interrupt.
*/
if (sci_port->irqs[0] < 0)
return -ENXIO;
if (sci_port->irqs[1] < 0)
for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
sci_port->irqs[i] = sci_port->irqs[0];
sci_port->params = sci_probe_regmap(p);
if (unlikely(sci_port->params == NULL))
return -EINVAL;
switch (p->type) {
case PORT_SCIFB:
sci_port->rx_trigger = 48;
break;
case PORT_HSCIF:
sci_port->rx_trigger = 64;
break;
case PORT_SCIFA:
sci_port->rx_trigger = 32;
break;
case PORT_SCIF:
if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
/* RX triggering not implemented for this IP */
sci_port->rx_trigger = 1;
else
sci_port->rx_trigger = 8;
break;
default:
sci_port->rx_trigger = 1;
break;
}
sci_port->rx_fifo_timeout = 0;
sci_port->hscif_tot = 0;
/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
* match the SoC datasheet, this should be investigated. Let platform
* data override the sampling rate for now.
*/
sci_port->sampling_rate_mask = p->sampling_rate
? SCI_SR(p->sampling_rate)
: sci_port->params->sampling_rate_mask;
if (!early) {
ret = sci_init_clocks(sci_port, &dev->dev);
if (ret < 0)
return ret;
port->dev = &dev->dev;
pm_runtime_enable(&dev->dev);
}
port->type = p->type;
port->flags = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
port->fifosize = sci_port->params->fifosize;
if (port->type == PORT_SCI && !dev->dev.of_node) {
if (sci_port->reg_size >= 0x20)
port->regshift = 2;
else
port->regshift = 1;
}
/*
* The UART port needs an IRQ value, so we peg this to the RX IRQ
* for the multi-IRQ ports, which is where we are primarily
* concerned with the shutdown path synchronization.
*
* For the muxed case there's nothing more to do.
*/
port->irq = sci_port->irqs[SCIx_RXI_IRQ];
port->irqflags = 0;
return 0;
}
static void sci_cleanup_single(struct sci_port *port)
{
pm_runtime_disable(port->port.dev);
}
#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
static void serial_console_putchar(struct uart_port *port, unsigned char ch)
{
sci_poll_put_char(port, ch);
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*/
static void serial_console_write(struct console *co, const char *s,
unsigned count)
{
struct sci_port *sci_port = &sci_ports[co->index];
struct uart_port *port = &sci_port->port;
unsigned short bits, ctrl, ctrl_temp;
unsigned long flags;
int locked = 1;
if (port->sysrq)
locked = 0;
else if (oops_in_progress)
locked = uart_port_trylock_irqsave(port, &flags);
else
uart_port_lock_irqsave(port, &flags);
/* first save SCSCR then disable interrupts, keep clock source */
ctrl = sci_serial_in(port, SCSCR);
ctrl_temp = SCSCR_RE | SCSCR_TE |
(sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
(ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
sci_serial_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
uart_console_write(port, s, count, serial_console_putchar);
/* wait until fifo is empty and last bit has been transmitted */
bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
while ((sci_serial_in(port, SCxSR) & bits) != bits)
cpu_relax();
/* restore the SCSCR */
sci_serial_out(port, SCSCR, ctrl);
if (locked)
uart_port_unlock_irqrestore(port, flags);
}
static int serial_console_setup(struct console *co, char *options)
{
struct sci_port *sci_port;
struct uart_port *port;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
int ret;
/*
* Refuse to handle any bogus ports.
*/
if (co->index < 0 || co->index >= SCI_NPORTS)
return -ENODEV;
sci_port = &sci_ports[co->index];
port = &sci_port->port;
/*
* Refuse to handle uninitialized ports.
*/
if (!port->ops)
return -ENODEV;
ret = sci_remap_port(port);
if (unlikely(ret != 0))
return ret;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct console serial_console = {
.name = "ttySC",
.device = uart_console_device,
.write = serial_console_write,
.setup = serial_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &sci_uart_driver,
};
#ifdef CONFIG_SUPERH
static char early_serial_buf[32];
static int early_serial_console_setup(struct console *co, char *options)
{
/*
* This early console is always registered using the earlyprintk=
* parameter, which does not call add_preferred_console(). Thus
* @options is always NULL and the options for this early console
* are passed using a custom buffer.
*/
WARN_ON(options);
return serial_console_setup(co, early_serial_buf);
}
static struct console early_serial_console = {
.name = "early_ttySC",
.write = serial_console_write,
.setup = early_serial_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
static int sci_probe_earlyprintk(struct platform_device *pdev)
{
const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
if (early_serial_console.data)
return -EEXIST;
early_serial_console.index = pdev->id;
sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
if (!strstr(early_serial_buf, "keep"))
early_serial_console.flags |= CON_BOOT;
register_console(&early_serial_console);
return 0;
}
#endif
#define SCI_CONSOLE (&serial_console)
#else
static inline int sci_probe_earlyprintk(struct platform_device *pdev)
{
return -EINVAL;
}
#define SCI_CONSOLE NULL
#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
static DEFINE_MUTEX(sci_uart_registration_lock);
static struct uart_driver sci_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "sci",
.dev_name = "ttySC",
.major = SCI_MAJOR,
.minor = SCI_MINOR_START,
.nr = SCI_NPORTS,
.cons = SCI_CONSOLE,
};
static void sci_remove(struct platform_device *dev)
{
struct sci_port *port = platform_get_drvdata(dev);
unsigned int type = port->port.type; /* uart_remove_... clears it */
sci_ports_in_use &= ~BIT(port->port.line);
uart_remove_one_port(&sci_uart_driver, &port->port);
sci_cleanup_single(port);
if (port->port.fifosize > 1)
device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
}
#define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype))
#define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16)
#define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff)
static const struct of_device_id of_sci_match[] __maybe_unused = {
/* SoC-specific types */
{
.compatible = "renesas,scif-r7s72100",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
},
{
.compatible = "renesas,scif-r7s9210",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
},
{
.compatible = "renesas,scif-r9a07g044",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
},
/* Family-specific types */
{
.compatible = "renesas,rcar-gen1-scif",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
}, {
.compatible = "renesas,rcar-gen2-scif",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
}, {
.compatible = "renesas,rcar-gen3-scif",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
}, {
.compatible = "renesas,rcar-gen4-scif",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
},
/* Generic types */
{
.compatible = "renesas,scif",
.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
}, {
.compatible = "renesas,scifa",
.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
}, {
.compatible = "renesas,scifb",
.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
}, {
.compatible = "renesas,hscif",
.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
}, {
.compatible = "renesas,sci",
.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
}, {
/* Terminator */
},
};
MODULE_DEVICE_TABLE(of, of_sci_match);
static void sci_reset_control_assert(void *data)
{
reset_control_assert(data);
}
static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
unsigned int *dev_id)
{
struct device_node *np = pdev->dev.of_node;
struct reset_control *rstc;
struct plat_sci_port *p;
struct sci_port *sp;
const void *data;
int id, ret;
if (!IS_ENABLED(CONFIG_OF) || !np)
return ERR_PTR(-EINVAL);
data = of_device_get_match_data(&pdev->dev);
rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
if (IS_ERR(rstc))
return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
"failed to get reset ctrl\n"));
ret = reset_control_deassert(rstc);
if (ret) {
dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
return ERR_PTR(ret);
}
ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
if (ret) {
dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
ret);
return ERR_PTR(ret);
}
p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
if (!p)
return ERR_PTR(-ENOMEM);
/* Get the line number from the aliases node. */
id = of_alias_get_id(np, "serial");
if (id < 0 && ~sci_ports_in_use)
id = ffz(sci_ports_in_use);
if (id < 0) {
dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
return ERR_PTR(-EINVAL);
}
if (id >= ARRAY_SIZE(sci_ports)) {
dev_err(&pdev->dev, "serial%d out of range\n", id);
return ERR_PTR(-EINVAL);
}
sp = &sci_ports[id];
*dev_id = id;
p->type = SCI_OF_TYPE(data);
p->regtype = SCI_OF_REGTYPE(data);
sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
return p;
}
static int sci_probe_single(struct platform_device *dev,
unsigned int index,
struct plat_sci_port *p,
struct sci_port *sciport)
{
int ret;
/* Sanity check */
if (unlikely(index >= SCI_NPORTS)) {
dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
index+1, SCI_NPORTS);
dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
return -EINVAL;
}
BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
if (sci_ports_in_use & BIT(index))
return -EBUSY;
mutex_lock(&sci_uart_registration_lock);
if (!sci_uart_driver.state) {
ret = uart_register_driver(&sci_uart_driver);
if (ret) {
mutex_unlock(&sci_uart_registration_lock);
return ret;
}
}
mutex_unlock(&sci_uart_registration_lock);
ret = sci_init_single(dev, sciport, index, p, false);
if (ret)
return ret;
sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
if (IS_ERR(sciport->gpios))
return PTR_ERR(sciport->gpios);
if (sciport->has_rtscts) {
if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
return -EINVAL;
}
sciport->port.flags |= UPF_HARD_FLOW;
}
ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
if (ret) {
sci_cleanup_single(sciport);
return ret;
}
return 0;
}
static int sci_probe(struct platform_device *dev)
{
struct plat_sci_port *p;
struct sci_port *sp;
unsigned int dev_id;
int ret;
/*
* If we've come here via earlyprintk initialization, head off to
* the special early probe. We don't have sufficient device state
* to make it beyond this yet.
*/
#ifdef CONFIG_SUPERH
if (is_sh_early_platform_device(dev))
return sci_probe_earlyprintk(dev);
#endif
if (dev->dev.of_node) {
p = sci_parse_dt(dev, &dev_id);
if (IS_ERR(p))
return PTR_ERR(p);
} else {
p = dev->dev.platform_data;
if (p == NULL) {
dev_err(&dev->dev, "no platform data supplied\n");
return -EINVAL;
}
dev_id = dev->id;
}
sp = &sci_ports[dev_id];
platform_set_drvdata(dev, sp);
ret = sci_probe_single(dev, dev_id, p, sp);
if (ret)
return ret;
if (sp->port.fifosize > 1) {
ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
if (ret)
return ret;
}
if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
sp->port.type == PORT_HSCIF) {
ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
if (ret) {
if (sp->port.fifosize > 1) {
device_remove_file(&dev->dev,
&dev_attr_rx_fifo_trigger);
}
return ret;
}
}
#ifdef CONFIG_SH_STANDARD_BIOS
sh_bios_gdb_detach();
#endif
sci_ports_in_use |= BIT(dev_id);
return 0;
}
static __maybe_unused int sci_suspend(struct device *dev)
{
struct sci_port *sport = dev_get_drvdata(dev);
if (sport)
uart_suspend_port(&sci_uart_driver, &sport->port);
return 0;
}
static __maybe_unused int sci_resume(struct device *dev)
{
struct sci_port *sport = dev_get_drvdata(dev);
if (sport)
uart_resume_port(&sci_uart_driver, &sport->port);
return 0;
}
static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
static struct platform_driver sci_driver = {
.probe = sci_probe,
.remove_new = sci_remove,
.driver = {
.name = "sh-sci",
.pm = &sci_dev_pm_ops,
.of_match_table = of_match_ptr(of_sci_match),
},
};
static int __init sci_init(void)
{
pr_info("%s\n", banner);
return platform_driver_register(&sci_driver);
}
static void __exit sci_exit(void)
{
platform_driver_unregister(&sci_driver);
if (sci_uart_driver.state)
uart_unregister_driver(&sci_uart_driver);
}
#if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
sh_early_platform_init_buffer("earlyprintk", &sci_driver,
early_serial_buf, ARRAY_SIZE(early_serial_buf));
#endif
#ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
static struct plat_sci_port port_cfg __initdata;
static int __init early_console_setup(struct earlycon_device *device,
int type)
{
if (!device->port.membase)
return -ENODEV;
device->port.type = type;
memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
port_cfg.type = type;
sci_ports[0].cfg = &port_cfg;
sci_ports[0].params = sci_probe_regmap(&port_cfg);
port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
sci_serial_out(&sci_ports[0].port, SCSCR,
SCSCR_RE | SCSCR_TE | port_cfg.scscr);
device->con->write = serial_console_write;
return 0;
}
static int __init sci_early_console_setup(struct earlycon_device *device,
const char *opt)
{
return early_console_setup(device, PORT_SCI);
}
static int __init scif_early_console_setup(struct earlycon_device *device,
const char *opt)
{
return early_console_setup(device, PORT_SCIF);
}
static int __init rzscifa_early_console_setup(struct earlycon_device *device,
const char *opt)
{
port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
return early_console_setup(device, PORT_SCIF);
}
static int __init scifa_early_console_setup(struct earlycon_device *device,
const char *opt)
{
return early_console_setup(device, PORT_SCIFA);
}
static int __init scifb_early_console_setup(struct earlycon_device *device,
const char *opt)
{
return early_console_setup(device, PORT_SCIFB);
}
static int __init hscif_early_console_setup(struct earlycon_device *device,
const char *opt)
{
return early_console_setup(device, PORT_HSCIF);
}
OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
#endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
module_init(sci_init);
module_exit(sci_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:sh-sci");
MODULE_AUTHOR("Paul Mundt");
MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
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