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392bceedb1
linux/drivers/tty/serial/imx.c
Philipp Zabel 392bceedb1 serial: imx: Fix DMA handling for IDLE condition aborts 
The driver configures the IDLE condition to interrupt the SDMA engine.
Since the SDMA UART ROM script doesn't clear the IDLE bit itself, this
caused repeated 1-byte DMA transfers, regardless of available data in the
RX FIFO. Also, when returning due to the IDLE condition, the UART ROM
script already increased its counter, causing residue to be off by one.

This patch clears the IDLE condition to avoid repeated 1-byte DMA transfers
and decreases count by when the DMA transfer was aborted due to the IDLE
condition, fixing serial transfers using DMA on i.MX6Q.

Reported-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:43:29 -07:00

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/*
* Driver for Motorola/Freescale IMX serial ports
*
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
*
* Author: Sascha Hauer <sascha@saschahauer.de>
* Copyright (C) 2004 Pengutronix
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/rational.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <asm/irq.h>
#include <linux/platform_data/serial-imx.h>
#include <linux/platform_data/dma-imx.h>
/* Register definitions */
#define URXD0 0x0 /* Receiver Register */
#define URTX0 0x40 /* Transmitter Register */
#define UCR1 0x80 /* Control Register 1 */
#define UCR2 0x84 /* Control Register 2 */
#define UCR3 0x88 /* Control Register 3 */
#define UCR4 0x8c /* Control Register 4 */
#define UFCR 0x90 /* FIFO Control Register */
#define USR1 0x94 /* Status Register 1 */
#define USR2 0x98 /* Status Register 2 */
#define UESC 0x9c /* Escape Character Register */
#define UTIM 0xa0 /* Escape Timer Register */
#define UBIR 0xa4 /* BRM Incremental Register */
#define UBMR 0xa8 /* BRM Modulator Register */
#define UBRC 0xac /* Baud Rate Count Register */
#define IMX21_ONEMS 0xb0 /* One Millisecond register */
#define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
/* UART Control Register Bit Fields.*/
#define URXD_DUMMY_READ (1<<16)
#define URXD_CHARRDY (1<<15)
#define URXD_ERR (1<<14)
#define URXD_OVRRUN (1<<13)
#define URXD_FRMERR (1<<12)
#define URXD_BRK (1<<11)
#define URXD_PRERR (1<<10)
#define URXD_RX_DATA (0xFF<<0)
#define UCR1_ADEN (1<<15) /* Auto detect interrupt */
#define UCR1_ADBR (1<<14) /* Auto detect baud rate */
#define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
#define UCR1_IDEN (1<<12) /* Idle condition interrupt */
#define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
#define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
#define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */
#define UCR1_IREN (1<<7) /* Infrared interface enable */
#define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
#define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
#define UCR1_SNDBRK (1<<4) /* Send break */
#define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */
#define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
#define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
#define UCR1_DOZE (1<<1) /* Doze */
#define UCR1_UARTEN (1<<0) /* UART enabled */
#define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
#define UCR2_IRTS (1<<14) /* Ignore RTS pin */
#define UCR2_CTSC (1<<13) /* CTS pin control */
#define UCR2_CTS (1<<12) /* Clear to send */
#define UCR2_ESCEN (1<<11) /* Escape enable */
#define UCR2_PREN (1<<8) /* Parity enable */
#define UCR2_PROE (1<<7) /* Parity odd/even */
#define UCR2_STPB (1<<6) /* Stop */
#define UCR2_WS (1<<5) /* Word size */
#define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
#define UCR2_ATEN (1<<3) /* Aging Timer Enable */
#define UCR2_TXEN (1<<2) /* Transmitter enabled */
#define UCR2_RXEN (1<<1) /* Receiver enabled */
#define UCR2_SRST (1<<0) /* SW reset */
#define UCR3_DTREN (1<<13) /* DTR interrupt enable */
#define UCR3_PARERREN (1<<12) /* Parity enable */
#define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
#define UCR3_DSR (1<<10) /* Data set ready */
#define UCR3_DCD (1<<9) /* Data carrier detect */
#define UCR3_RI (1<<8) /* Ring indicator */
#define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
#define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
#define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
#define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
#define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
#define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
#define UCR3_BPEN (1<<0) /* Preset registers enable */
#define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
#define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
#define UCR4_INVR (1<<9) /* Inverted infrared reception */
#define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
#define UCR4_WKEN (1<<7) /* Wake interrupt enable */
#define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
#define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
#define UCR4_IRSC (1<<5) /* IR special case */
#define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
#define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
#define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
#define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
#define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
#define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
#define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
#define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
#define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
#define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
#define USR1_RTSS (1<<14) /* RTS pin status */
#define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
#define USR1_RTSD (1<<12) /* RTS delta */
#define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
#define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
#define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
#define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */
#define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
#define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
#define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
#define USR2_ADET (1<<15) /* Auto baud rate detect complete */
#define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
#define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
#define USR2_IDLE (1<<12) /* Idle condition */
#define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
#define USR2_WAKE (1<<7) /* Wake */
#define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
#define USR2_TXDC (1<<3) /* Transmitter complete */
#define USR2_BRCD (1<<2) /* Break condition */
#define USR2_ORE (1<<1) /* Overrun error */
#define USR2_RDR (1<<0) /* Recv data ready */
#define UTS_FRCPERR (1<<13) /* Force parity error */
#define UTS_LOOP (1<<12) /* Loop tx and rx */
#define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
#define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
#define UTS_TXFULL (1<<4) /* TxFIFO full */
#define UTS_RXFULL (1<<3) /* RxFIFO full */
#define UTS_SOFTRST (1<<0) /* Software reset */
/* We've been assigned a range on the "Low-density serial ports" major */
#define SERIAL_IMX_MAJOR 207
#define MINOR_START 16
#define DEV_NAME "ttymxc"
/*
* This determines how often we check the modem status signals
* for any change. They generally aren't connected to an IRQ
* so we have to poll them. We also check immediately before
* filling the TX fifo incase CTS has been dropped.
*/
#define MCTRL_TIMEOUT (250*HZ/1000)
#define DRIVER_NAME "IMX-uart"
#define UART_NR 8
/* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
enum imx_uart_type {
IMX1_UART,
IMX21_UART,
IMX6Q_UART,
};
/* device type dependent stuff */
struct imx_uart_data {
unsigned uts_reg;
enum imx_uart_type devtype;
};
struct imx_port {
struct uart_port port;
struct timer_list timer;
unsigned int old_status;
unsigned int have_rtscts:1;
unsigned int dte_mode:1;
unsigned int irda_inv_rx:1;
unsigned int irda_inv_tx:1;
unsigned short trcv_delay; /* transceiver delay */
struct clk *clk_ipg;
struct clk *clk_per;
const struct imx_uart_data *devdata;
/* DMA fields */
unsigned int dma_is_inited:1;
unsigned int dma_is_enabled:1;
unsigned int dma_is_rxing:1;
unsigned int dma_is_txing:1;
struct dma_chan *dma_chan_rx, *dma_chan_tx;
struct scatterlist rx_sgl, tx_sgl[2];
void *rx_buf;
unsigned int tx_bytes;
unsigned int dma_tx_nents;
wait_queue_head_t dma_wait;
};
struct imx_port_ucrs {
unsigned int ucr1;
unsigned int ucr2;
unsigned int ucr3;
};
static struct imx_uart_data imx_uart_devdata[] = {
[IMX1_UART] = {
.uts_reg = IMX1_UTS,
.devtype = IMX1_UART,
},
[IMX21_UART] = {
.uts_reg = IMX21_UTS,
.devtype = IMX21_UART,
},
[IMX6Q_UART] = {
.uts_reg = IMX21_UTS,
.devtype = IMX6Q_UART,
},
};
static struct platform_device_id imx_uart_devtype[] = {
{
.name = "imx1-uart",
.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
}, {
.name = "imx21-uart",
.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
}, {
.name = "imx6q-uart",
.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
static const struct of_device_id imx_uart_dt_ids[] = {
{ .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
static inline unsigned uts_reg(struct imx_port *sport)
{
return sport->devdata->uts_reg;
}
static inline int is_imx1_uart(struct imx_port *sport)
{
return sport->devdata->devtype == IMX1_UART;
}
static inline int is_imx21_uart(struct imx_port *sport)
{
return sport->devdata->devtype == IMX21_UART;
}
static inline int is_imx6q_uart(struct imx_port *sport)
{
return sport->devdata->devtype == IMX6Q_UART;
}
/*
* Save and restore functions for UCR1, UCR2 and UCR3 registers
*/
#if defined(CONFIG_SERIAL_IMX_CONSOLE)
static void imx_port_ucrs_save(struct uart_port *port,
struct imx_port_ucrs *ucr)
{
/* save control registers */
ucr->ucr1 = readl(port->membase + UCR1);
ucr->ucr2 = readl(port->membase + UCR2);
ucr->ucr3 = readl(port->membase + UCR3);
}
static void imx_port_ucrs_restore(struct uart_port *port,
struct imx_port_ucrs *ucr)
{
/* restore control registers */
writel(ucr->ucr1, port->membase + UCR1);
writel(ucr->ucr2, port->membase + UCR2);
writel(ucr->ucr3, port->membase + UCR3);
}
#endif
/*
* Handle any change of modem status signal since we were last called.
*/
static void imx_mctrl_check(struct imx_port *sport)
{
unsigned int status, changed;
status = sport->port.ops->get_mctrl(&sport->port);
changed = status ^ sport->old_status;
if (changed == 0)
return;
sport->old_status = status;
if (changed & TIOCM_RI)
sport->port.icount.rng++;
if (changed & TIOCM_DSR)
sport->port.icount.dsr++;
if (changed & TIOCM_CAR)
uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
if (changed & TIOCM_CTS)
uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
}
/*
* This is our per-port timeout handler, for checking the
* modem status signals.
*/
static void imx_timeout(unsigned long data)
{
struct imx_port *sport = (struct imx_port *)data;
unsigned long flags;
if (sport->port.state) {
spin_lock_irqsave(&sport->port.lock, flags);
imx_mctrl_check(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
}
}
/*
* interrupts disabled on entry
*/
static void imx_stop_tx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
/*
* We are maybe in the SMP context, so if the DMA TX thread is running
* on other cpu, we have to wait for it to finish.
*/
if (sport->dma_is_enabled && sport->dma_is_txing)
return;
temp = readl(port->membase + UCR1);
writel(temp & ~UCR1_TXMPTYEN, port->membase + UCR1);
/* in rs485 mode disable transmitter if shifter is empty */
if (port->rs485.flags & SER_RS485_ENABLED &&
readl(port->membase + USR2) & USR2_TXDC) {
temp = readl(port->membase + UCR2);
if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
temp &= ~UCR2_CTS;
else
temp |= UCR2_CTS;
writel(temp, port->membase + UCR2);
temp = readl(port->membase + UCR4);
temp &= ~UCR4_TCEN;
writel(temp, port->membase + UCR4);
}
}
/*
* interrupts disabled on entry
*/
static void imx_stop_rx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
if (sport->dma_is_enabled && sport->dma_is_rxing) {
if (sport->port.suspended) {
dmaengine_terminate_all(sport->dma_chan_rx);
sport->dma_is_rxing = 0;
} else {
return;
}
}
temp = readl(sport->port.membase + UCR2);
writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
/* disable the `Receiver Ready Interrrupt` */
temp = readl(sport->port.membase + UCR1);
writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
}
/*
* Set the modem control timer to fire immediately.
*/
static void imx_enable_ms(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
mod_timer(&sport->timer, jiffies);
}
static void imx_dma_tx(struct imx_port *sport);
static inline void imx_transmit_buffer(struct imx_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
unsigned long temp;
if (sport->port.x_char) {
/* Send next char */
writel(sport->port.x_char, sport->port.membase + URTX0);
sport->port.icount.tx++;
sport->port.x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
imx_stop_tx(&sport->port);
return;
}
if (sport->dma_is_enabled) {
/*
* We've just sent a X-char Ensure the TX DMA is enabled
* and the TX IRQ is disabled.
**/
temp = readl(sport->port.membase + UCR1);
temp &= ~UCR1_TXMPTYEN;
if (sport->dma_is_txing) {
temp |= UCR1_TDMAEN;
writel(temp, sport->port.membase + UCR1);
} else {
writel(temp, sport->port.membase + UCR1);
imx_dma_tx(sport);
}
}
while (!uart_circ_empty(xmit) &&
!(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) {
/* send xmit->buf[xmit->tail]
* out the port here */
writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx++;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (uart_circ_empty(xmit))
imx_stop_tx(&sport->port);
}
static void dma_tx_callback(void *data)
{
struct imx_port *sport = data;
struct scatterlist *sgl = &sport->tx_sgl[0];
struct circ_buf *xmit = &sport->port.state->xmit;
unsigned long flags;
unsigned long temp;
spin_lock_irqsave(&sport->port.lock, flags);
dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
temp = readl(sport->port.membase + UCR1);
temp &= ~UCR1_TDMAEN;
writel(temp, sport->port.membase + UCR1);
/* update the stat */
xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx += sport->tx_bytes;
dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
sport->dma_is_txing = 0;
spin_unlock_irqrestore(&sport->port.lock, flags);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (waitqueue_active(&sport->dma_wait)) {
wake_up(&sport->dma_wait);
dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
return;
}
spin_lock_irqsave(&sport->port.lock, flags);
if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
imx_dma_tx(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static void imx_dma_tx(struct imx_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
struct scatterlist *sgl = sport->tx_sgl;
struct dma_async_tx_descriptor *desc;
struct dma_chan *chan = sport->dma_chan_tx;
struct device *dev = sport->port.dev;
unsigned long temp;
int ret;
if (sport->dma_is_txing)
return;
sport->tx_bytes = uart_circ_chars_pending(xmit);
if (xmit->tail < xmit->head) {
sport->dma_tx_nents = 1;
sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
} else {
sport->dma_tx_nents = 2;
sg_init_table(sgl, 2);
sg_set_buf(sgl, xmit->buf + xmit->tail,
UART_XMIT_SIZE - xmit->tail);
sg_set_buf(sgl + 1, xmit->buf, xmit->head);
}
ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
if (ret == 0) {
dev_err(dev, "DMA mapping error for TX.\n");
return;
}
desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
if (!desc) {
dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
dev_err(dev, "We cannot prepare for the TX slave dma!\n");
return;
}
desc->callback = dma_tx_callback;
desc->callback_param = sport;
dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
uart_circ_chars_pending(xmit));
temp = readl(sport->port.membase + UCR1);
temp |= UCR1_TDMAEN;
writel(temp, sport->port.membase + UCR1);
/* fire it */
sport->dma_is_txing = 1;
dmaengine_submit(desc);
dma_async_issue_pending(chan);
return;
}
/*
* interrupts disabled on entry
*/
static void imx_start_tx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
if (port->rs485.flags & SER_RS485_ENABLED) {
/* enable transmitter and shifter empty irq */
temp = readl(port->membase + UCR2);
if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
temp &= ~UCR2_CTS;
else
temp |= UCR2_CTS;
writel(temp, port->membase + UCR2);
temp = readl(port->membase + UCR4);
temp |= UCR4_TCEN;
writel(temp, port->membase + UCR4);
}
if (!sport->dma_is_enabled) {
temp = readl(sport->port.membase + UCR1);
writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
}
if (sport->dma_is_enabled) {
if (sport->port.x_char) {
/* We have X-char to send, so enable TX IRQ and
* disable TX DMA to let TX interrupt to send X-char */
temp = readl(sport->port.membase + UCR1);
temp &= ~UCR1_TDMAEN;
temp |= UCR1_TXMPTYEN;
writel(temp, sport->port.membase + UCR1);
return;
}
if (!uart_circ_empty(&port->state->xmit) &&
!uart_tx_stopped(port))
imx_dma_tx(sport);
return;
}
}
static irqreturn_t imx_rtsint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
unsigned int val;
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
writel(USR1_RTSD, sport->port.membase + USR1);
val = readl(sport->port.membase + USR1) & USR1_RTSS;
uart_handle_cts_change(&sport->port, !!val);
wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
spin_unlock_irqrestore(&sport->port.lock, flags);
return IRQ_HANDLED;
}
static irqreturn_t imx_txint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
imx_transmit_buffer(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
return IRQ_HANDLED;
}
static irqreturn_t imx_rxint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
unsigned int rx, flg, ignored = 0;
struct tty_port *port = &sport->port.state->port;
unsigned long flags, temp;
spin_lock_irqsave(&sport->port.lock, flags);
while (readl(sport->port.membase + USR2) & USR2_RDR) {
flg = TTY_NORMAL;
sport->port.icount.rx++;
rx = readl(sport->port.membase + URXD0);
temp = readl(sport->port.membase + USR2);
if (temp & USR2_BRCD) {
writel(USR2_BRCD, sport->port.membase + USR2);
if (uart_handle_break(&sport->port))
continue;
}
if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
continue;
if (unlikely(rx & URXD_ERR)) {
if (rx & URXD_BRK)
sport->port.icount.brk++;
else if (rx & URXD_PRERR)
sport->port.icount.parity++;
else if (rx & URXD_FRMERR)
sport->port.icount.frame++;
if (rx & URXD_OVRRUN)
sport->port.icount.overrun++;
if (rx & sport->port.ignore_status_mask) {
if (++ignored > 100)
goto out;
continue;
}
rx &= (sport->port.read_status_mask | 0xFF);
if (rx & URXD_BRK)
flg = TTY_BREAK;
else if (rx & URXD_PRERR)
flg = TTY_PARITY;
else if (rx & URXD_FRMERR)
flg = TTY_FRAME;
if (rx & URXD_OVRRUN)
flg = TTY_OVERRUN;
#ifdef SUPPORT_SYSRQ
sport->port.sysrq = 0;
#endif
}
if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
goto out;
tty_insert_flip_char(port, rx, flg);
}
out:
spin_unlock_irqrestore(&sport->port.lock, flags);
tty_flip_buffer_push(port);
return IRQ_HANDLED;
}
static int start_rx_dma(struct imx_port *sport);
/*
* If the RXFIFO is filled with some data, and then we
* arise a DMA operation to receive them.
*/
static void imx_dma_rxint(struct imx_port *sport)
{
unsigned long temp;
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
temp = readl(sport->port.membase + USR2);
if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
sport->dma_is_rxing = 1;
/* disable the `Recerver Ready Interrrupt` */
temp = readl(sport->port.membase + UCR1);
temp &= ~(UCR1_RRDYEN);
writel(temp, sport->port.membase + UCR1);
/* tell the DMA to receive the data. */
start_rx_dma(sport);
}
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static irqreturn_t imx_int(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
unsigned int sts;
unsigned int sts2;
sts = readl(sport->port.membase + USR1);
sts2 = readl(sport->port.membase + USR2);
if (sts & USR1_RRDY) {
if (sport->dma_is_enabled)
imx_dma_rxint(sport);
else
imx_rxint(irq, dev_id);
}
if ((sts & USR1_TRDY &&
readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN) ||
(sts2 & USR2_TXDC &&
readl(sport->port.membase + UCR4) & UCR4_TCEN))
imx_txint(irq, dev_id);
if (sts & USR1_RTSD)
imx_rtsint(irq, dev_id);
if (sts & USR1_AWAKE)
writel(USR1_AWAKE, sport->port.membase + USR1);
if (sts2 & USR2_ORE) {
dev_err(sport->port.dev, "Rx FIFO overrun\n");
sport->port.icount.overrun++;
writel(USR2_ORE, sport->port.membase + USR2);
}
return IRQ_HANDLED;
}
/*
* Return TIOCSER_TEMT when transmitter is not busy.
*/
static unsigned int imx_tx_empty(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned int ret;
ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
/* If the TX DMA is working, return 0. */
if (sport->dma_is_enabled && sport->dma_is_txing)
ret = 0;
return ret;
}
/*
* We have a modem side uart, so the meanings of RTS and CTS are inverted.
*/
static unsigned int imx_get_mctrl(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
if (readl(sport->port.membase + USR1) & USR1_RTSS)
tmp |= TIOCM_CTS;
if (readl(sport->port.membase + UCR2) & UCR2_CTS)
tmp |= TIOCM_RTS;
if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
tmp |= TIOCM_LOOP;
return tmp;
}
static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
if (!(port->rs485.flags & SER_RS485_ENABLED)) {
temp = readl(sport->port.membase + UCR2);
temp &= ~(UCR2_CTS | UCR2_CTSC);
if (mctrl & TIOCM_RTS)
temp |= UCR2_CTS | UCR2_CTSC;
writel(temp, sport->port.membase + UCR2);
}
temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
if (mctrl & TIOCM_LOOP)
temp |= UTS_LOOP;
writel(temp, sport->port.membase + uts_reg(sport));
}
/*
* Interrupts always disabled.
*/
static void imx_break_ctl(struct uart_port *port, int break_state)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long flags, temp;
spin_lock_irqsave(&sport->port.lock, flags);
temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
if (break_state != 0)
temp |= UCR1_SNDBRK;
writel(temp, sport->port.membase + UCR1);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
#define TXTL 2 /* reset default */
#define RXTL 1 /* reset default */
static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
{
unsigned int val;
/* set receiver / transmitter trigger level */
val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
val |= TXTL << UFCR_TXTL_SHF | RXTL;
writel(val, sport->port.membase + UFCR);
return 0;
}
#define RX_BUF_SIZE (PAGE_SIZE)
static void imx_rx_dma_done(struct imx_port *sport)
{
unsigned long temp;
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
/* Enable this interrupt when the RXFIFO is empty. */
temp = readl(sport->port.membase + UCR1);
temp |= UCR1_RRDYEN;
writel(temp, sport->port.membase + UCR1);
sport->dma_is_rxing = 0;
/* Is the shutdown waiting for us? */
if (waitqueue_active(&sport->dma_wait))
wake_up(&sport->dma_wait);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
/*
* There are three kinds of RX DMA interrupts(such as in the MX6Q):
* [1] the RX DMA buffer is full.
* [2] the Aging timer expires(wait for 8 bytes long)
* [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
*
* The [2] is trigger when a character was been sitting in the FIFO
* meanwhile [3] can wait for 32 bytes long when the RX line is
* on IDLE state and RxFIFO is empty.
*/
static void dma_rx_callback(void *data)
{
struct imx_port *sport = data;
struct dma_chan *chan = sport->dma_chan_rx;
struct scatterlist *sgl = &sport->rx_sgl;
struct tty_port *port = &sport->port.state->port;
struct dma_tx_state state;
enum dma_status status;
unsigned int count;
/* unmap it first */
dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
count = RX_BUF_SIZE - state.residue;
if (readl(sport->port.membase + USR2) & USR2_IDLE) {
/* In condition [3] the SDMA counted up too early */
count--;
writel(USR2_IDLE, sport->port.membase + USR2);
}
dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
if (count) {
if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ))
tty_insert_flip_string(port, sport->rx_buf, count);
tty_flip_buffer_push(port);
start_rx_dma(sport);
} else if (readl(sport->port.membase + USR2) & USR2_RDR) {
/*
* start rx_dma directly once data in RXFIFO, more efficient
* than before:
* 1. call imx_rx_dma_done to stop dma if no data received
* 2. wait next RDR interrupt to start dma transfer.
*/
start_rx_dma(sport);
} else {
/*
* stop dma to prevent too many IDLE event trigged if no data
* in RXFIFO
*/
imx_rx_dma_done(sport);
}
}
static int start_rx_dma(struct imx_port *sport)
{
struct scatterlist *sgl = &sport->rx_sgl;
struct dma_chan *chan = sport->dma_chan_rx;
struct device *dev = sport->port.dev;
struct dma_async_tx_descriptor *desc;
int ret;
sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
if (ret == 0) {
dev_err(dev, "DMA mapping error for RX.\n");
return -EINVAL;
}
desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
if (!desc) {
dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
dev_err(dev, "We cannot prepare for the RX slave dma!\n");
return -EINVAL;
}
desc->callback = dma_rx_callback;
desc->callback_param = sport;
dev_dbg(dev, "RX: prepare for the DMA.\n");
dmaengine_submit(desc);
dma_async_issue_pending(chan);
return 0;
}
static void imx_uart_dma_exit(struct imx_port *sport)
{
if (sport->dma_chan_rx) {
dma_release_channel(sport->dma_chan_rx);
sport->dma_chan_rx = NULL;
kfree(sport->rx_buf);
sport->rx_buf = NULL;
}
if (sport->dma_chan_tx) {
dma_release_channel(sport->dma_chan_tx);
sport->dma_chan_tx = NULL;
}
sport->dma_is_inited = 0;
}
static int imx_uart_dma_init(struct imx_port *sport)
{
struct dma_slave_config slave_config = {};
struct device *dev = sport->port.dev;
int ret;
/* Prepare for RX : */
sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
if (!sport->dma_chan_rx) {
dev_dbg(dev, "cannot get the DMA channel.\n");
ret = -EINVAL;
goto err;
}
slave_config.direction = DMA_DEV_TO_MEM;
slave_config.src_addr = sport->port.mapbase + URXD0;
slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
slave_config.src_maxburst = RXTL;
ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
if (ret) {
dev_err(dev, "error in RX dma configuration.\n");
goto err;
}
sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!sport->rx_buf) {
ret = -ENOMEM;
goto err;
}
/* Prepare for TX : */
sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
if (!sport->dma_chan_tx) {
dev_err(dev, "cannot get the TX DMA channel!\n");
ret = -EINVAL;
goto err;
}
slave_config.direction = DMA_MEM_TO_DEV;
slave_config.dst_addr = sport->port.mapbase + URTX0;
slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
slave_config.dst_maxburst = TXTL;
ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
if (ret) {
dev_err(dev, "error in TX dma configuration.");
goto err;
}
sport->dma_is_inited = 1;
return 0;
err:
imx_uart_dma_exit(sport);
return ret;
}
static void imx_enable_dma(struct imx_port *sport)
{
unsigned long temp;
init_waitqueue_head(&sport->dma_wait);
/* set UCR1 */
temp = readl(sport->port.membase + UCR1);
temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
/* wait for 32 idle frames for IDDMA interrupt */
UCR1_ICD_REG(3);
writel(temp, sport->port.membase + UCR1);
/* set UCR4 */
temp = readl(sport->port.membase + UCR4);
temp |= UCR4_IDDMAEN;
writel(temp, sport->port.membase + UCR4);
sport->dma_is_enabled = 1;
}
static void imx_disable_dma(struct imx_port *sport)
{
unsigned long temp;
/* clear UCR1 */
temp = readl(sport->port.membase + UCR1);
temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
writel(temp, sport->port.membase + UCR1);
/* clear UCR2 */
temp = readl(sport->port.membase + UCR2);
temp &= ~(UCR2_CTSC | UCR2_CTS);
writel(temp, sport->port.membase + UCR2);
/* clear UCR4 */
temp = readl(sport->port.membase + UCR4);
temp &= ~UCR4_IDDMAEN;
writel(temp, sport->port.membase + UCR4);
sport->dma_is_enabled = 0;
}
/* half the RX buffer size */
#define CTSTL 16
static int imx_startup(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
int retval, i;
unsigned long flags, temp;
retval = clk_prepare_enable(sport->clk_per);
if (retval)
return retval;
retval = clk_prepare_enable(sport->clk_ipg);
if (retval) {
clk_disable_unprepare(sport->clk_per);
return retval;
}
imx_setup_ufcr(sport, 0);
/* disable the DREN bit (Data Ready interrupt enable) before
* requesting IRQs
*/
temp = readl(sport->port.membase + UCR4);
/* set the trigger level for CTS */
temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
temp |= CTSTL << UCR4_CTSTL_SHF;
writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
/* Reset fifo's and state machines */
i = 100;
temp = readl(sport->port.membase + UCR2);
temp &= ~UCR2_SRST;
writel(temp, sport->port.membase + UCR2);
while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
udelay(1);
/* Can we enable the DMA support? */
if (is_imx6q_uart(sport) && !uart_console(port) &&
!sport->dma_is_inited)
imx_uart_dma_init(sport);
spin_lock_irqsave(&sport->port.lock, flags);
/*
* Finally, clear and enable interrupts
*/
writel(USR1_RTSD, sport->port.membase + USR1);
writel(USR2_ORE, sport->port.membase + USR2);
if (sport->dma_is_inited && !sport->dma_is_enabled)
imx_enable_dma(sport);
temp = readl(sport->port.membase + UCR1);
temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
writel(temp, sport->port.membase + UCR1);
temp = readl(sport->port.membase + UCR4);
temp |= UCR4_OREN;
writel(temp, sport->port.membase + UCR4);
temp = readl(sport->port.membase + UCR2);
temp |= (UCR2_RXEN | UCR2_TXEN);
if (!sport->have_rtscts)
temp |= UCR2_IRTS;
writel(temp, sport->port.membase + UCR2);
if (!is_imx1_uart(sport)) {
temp = readl(sport->port.membase + UCR3);
temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
writel(temp, sport->port.membase + UCR3);
}
/*
* Enable modem status interrupts
*/
imx_enable_ms(&sport->port);
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static void imx_shutdown(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
unsigned long flags;
if (sport->dma_is_enabled) {
int ret;
/* We have to wait for the DMA to finish. */
ret = wait_event_interruptible(sport->dma_wait,
!sport->dma_is_rxing && !sport->dma_is_txing);
if (ret != 0) {
sport->dma_is_rxing = 0;
sport->dma_is_txing = 0;
dmaengine_terminate_all(sport->dma_chan_tx);
dmaengine_terminate_all(sport->dma_chan_rx);
}
spin_lock_irqsave(&sport->port.lock, flags);
imx_stop_tx(port);
imx_stop_rx(port);
imx_disable_dma(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
imx_uart_dma_exit(sport);
}
spin_lock_irqsave(&sport->port.lock, flags);
temp = readl(sport->port.membase + UCR2);
temp &= ~(UCR2_TXEN);
writel(temp, sport->port.membase + UCR2);
spin_unlock_irqrestore(&sport->port.lock, flags);
/*
* Stop our timer.
*/
del_timer_sync(&sport->timer);
/*
* Disable all interrupts, port and break condition.
*/
spin_lock_irqsave(&sport->port.lock, flags);
temp = readl(sport->port.membase + UCR1);
temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
writel(temp, sport->port.membase + UCR1);
spin_unlock_irqrestore(&sport->port.lock, flags);
clk_disable_unprepare(sport->clk_per);
clk_disable_unprepare(sport->clk_ipg);
}
static void imx_flush_buffer(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
struct scatterlist *sgl = &sport->tx_sgl[0];
unsigned long temp;
int i = 100, ubir, ubmr, uts;
if (!sport->dma_chan_tx)
return;
sport->tx_bytes = 0;
dmaengine_terminate_all(sport->dma_chan_tx);
if (sport->dma_is_txing) {
dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
temp = readl(sport->port.membase + UCR1);
temp &= ~UCR1_TDMAEN;
writel(temp, sport->port.membase + UCR1);
sport->dma_is_txing = false;
}
/*
* According to the Reference Manual description of the UART SRST bit:
* "Reset the transmit and receive state machines,
* all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
* and UTS[6-3]". As we don't need to restore the old values from
* USR1, USR2, URXD, UTXD, only save/restore the other four registers
*/
ubir = readl(sport->port.membase + UBIR);
ubmr = readl(sport->port.membase + UBMR);
uts = readl(sport->port.membase + IMX21_UTS);
temp = readl(sport->port.membase + UCR2);
temp &= ~UCR2_SRST;
writel(temp, sport->port.membase + UCR2);
while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
udelay(1);
/* Restore the registers */
writel(ubir, sport->port.membase + UBIR);
writel(ubmr, sport->port.membase + UBMR);
writel(uts, sport->port.membase + IMX21_UTS);
}
static void
imx_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long flags;
unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
unsigned int div, ufcr;
unsigned long num, denom;
uint64_t tdiv64;
/*
* We only support CS7 and CS8.
*/
while ((termios->c_cflag & CSIZE) != CS7 &&
(termios->c_cflag & CSIZE) != CS8) {
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= old_csize;
old_csize = CS8;
}
if ((termios->c_cflag & CSIZE) == CS8)
ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
else
ucr2 = UCR2_SRST | UCR2_IRTS;
if (termios->c_cflag & CRTSCTS) {
if (sport->have_rtscts) {
ucr2 &= ~UCR2_IRTS;
if (port->rs485.flags & SER_RS485_ENABLED) {
/*
* RTS is mandatory for rs485 operation, so keep
* it under manual control and keep transmitter
* disabled.
*/
if (!(port->rs485.flags &
SER_RS485_RTS_AFTER_SEND))
ucr2 |= UCR2_CTS;
} else {
ucr2 |= UCR2_CTSC;
}
} else {
termios->c_cflag &= ~CRTSCTS;
}
} else if (port->rs485.flags & SER_RS485_ENABLED)
/* disable transmitter */
if (!(port->rs485.flags & SER_RS485_RTS_AFTER_SEND))
ucr2 |= UCR2_CTS;
if (termios->c_cflag & CSTOPB)
ucr2 |= UCR2_STPB;
if (termios->c_cflag & PARENB) {
ucr2 |= UCR2_PREN;
if (termios->c_cflag & PARODD)
ucr2 |= UCR2_PROE;
}
del_timer_sync(&sport->timer);
/*
* Ask the core to calculate the divisor for us.
*/
baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
quot = uart_get_divisor(port, baud);
spin_lock_irqsave(&sport->port.lock, flags);
sport->port.read_status_mask = 0;
if (termios->c_iflag & INPCK)
sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
if (termios->c_iflag & (BRKINT | PARMRK))
sport->port.read_status_mask |= URXD_BRK;
/*
* Characters to ignore
*/
sport->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
if (termios->c_iflag & IGNBRK) {
sport->port.ignore_status_mask |= URXD_BRK;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |= URXD_OVRRUN;
}
if ((termios->c_cflag & CREAD) == 0)
sport->port.ignore_status_mask |= URXD_DUMMY_READ;
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
/*
* disable interrupts and drain transmitter
*/
old_ucr1 = readl(sport->port.membase + UCR1);
writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
sport->port.membase + UCR1);
while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
barrier();
/* then, disable everything */
old_txrxen = readl(sport->port.membase + UCR2);
writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
sport->port.membase + UCR2);
old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
/* custom-baudrate handling */
div = sport->port.uartclk / (baud * 16);
if (baud == 38400 && quot != div)
baud = sport->port.uartclk / (quot * 16);
div = sport->port.uartclk / (baud * 16);
if (div > 7)
div = 7;
if (!div)
div = 1;
rational_best_approximation(16 * div * baud, sport->port.uartclk,
1 << 16, 1 << 16, &num, &denom);
tdiv64 = sport->port.uartclk;
tdiv64 *= num;
do_div(tdiv64, denom * 16 * div);
tty_termios_encode_baud_rate(termios,
(speed_t)tdiv64, (speed_t)tdiv64);
num -= 1;
denom -= 1;
ufcr = readl(sport->port.membase + UFCR);
ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
if (sport->dte_mode)
ufcr |= UFCR_DCEDTE;
writel(ufcr, sport->port.membase + UFCR);
writel(num, sport->port.membase + UBIR);
writel(denom, sport->port.membase + UBMR);
if (!is_imx1_uart(sport))
writel(sport->port.uartclk / div / 1000,
sport->port.membase + IMX21_ONEMS);
writel(old_ucr1, sport->port.membase + UCR1);
/* set the parity, stop bits and data size */
writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
imx_enable_ms(&sport->port);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static const char *imx_type(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
return sport->port.type == PORT_IMX ? "IMX" : NULL;
}
/*
* Configure/autoconfigure the port.
*/
static void imx_config_port(struct uart_port *port, int flags)
{
struct imx_port *sport = (struct imx_port *)port;
if (flags & UART_CONFIG_TYPE)
sport->port.type = PORT_IMX;
}
/*
* Verify the new serial_struct (for TIOCSSERIAL).
* The only change we allow are to the flags and type, and
* even then only between PORT_IMX and PORT_UNKNOWN
*/
static int
imx_verify_port(struct uart_port *port, struct serial_struct *ser)
{
struct imx_port *sport = (struct imx_port *)port;
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
ret = -EINVAL;
if (sport->port.irq != ser->irq)
ret = -EINVAL;
if (ser->io_type != UPIO_MEM)
ret = -EINVAL;
if (sport->port.uartclk / 16 != ser->baud_base)
ret = -EINVAL;
if (sport->port.mapbase != (unsigned long)ser->iomem_base)
ret = -EINVAL;
if (sport->port.iobase != ser->port)
ret = -EINVAL;
if (ser->hub6 != 0)
ret = -EINVAL;
return ret;
}
#if defined(CONFIG_CONSOLE_POLL)
static int imx_poll_init(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long flags;
unsigned long temp;
int retval;
retval = clk_prepare_enable(sport->clk_ipg);
if (retval)
return retval;
retval = clk_prepare_enable(sport->clk_per);
if (retval)
clk_disable_unprepare(sport->clk_ipg);
imx_setup_ufcr(sport, 0);
spin_lock_irqsave(&sport->port.lock, flags);
temp = readl(sport->port.membase + UCR1);
if (is_imx1_uart(sport))
temp |= IMX1_UCR1_UARTCLKEN;
temp |= UCR1_UARTEN | UCR1_RRDYEN;
temp &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN);
writel(temp, sport->port.membase + UCR1);
temp = readl(sport->port.membase + UCR2);
temp |= UCR2_RXEN;
writel(temp, sport->port.membase + UCR2);
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static int imx_poll_get_char(struct uart_port *port)
{
if (!(readl_relaxed(port->membase + USR2) & USR2_RDR))
return NO_POLL_CHAR;
return readl_relaxed(port->membase + URXD0) & URXD_RX_DATA;
}
static void imx_poll_put_char(struct uart_port *port, unsigned char c)
{
unsigned int status;
/* drain */
do {
status = readl_relaxed(port->membase + USR1);
} while (~status & USR1_TRDY);
/* write */
writel_relaxed(c, port->membase + URTX0);
/* flush */
do {
status = readl_relaxed(port->membase + USR2);
} while (~status & USR2_TXDC);
}
#endif
static int imx_rs485_config(struct uart_port *port,
struct serial_rs485 *rs485conf)
{
struct imx_port *sport = (struct imx_port *)port;
/* unimplemented */
rs485conf->delay_rts_before_send = 0;
rs485conf->delay_rts_after_send = 0;
rs485conf->flags |= SER_RS485_RX_DURING_TX;
/* RTS is required to control the transmitter */
if (!sport->have_rtscts)
rs485conf->flags &= ~SER_RS485_ENABLED;
if (rs485conf->flags & SER_RS485_ENABLED) {
unsigned long temp;
/* disable transmitter */
temp = readl(sport->port.membase + UCR2);
temp &= ~UCR2_CTSC;
if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
temp &= ~UCR2_CTS;
else
temp |= UCR2_CTS;
writel(temp, sport->port.membase + UCR2);
}
port->rs485 = *rs485conf;
return 0;
}
static struct uart_ops imx_pops = {
.tx_empty = imx_tx_empty,
.set_mctrl = imx_set_mctrl,
.get_mctrl = imx_get_mctrl,
.stop_tx = imx_stop_tx,
.start_tx = imx_start_tx,
.stop_rx = imx_stop_rx,
.enable_ms = imx_enable_ms,
.break_ctl = imx_break_ctl,
.startup = imx_startup,
.shutdown = imx_shutdown,
.flush_buffer = imx_flush_buffer,
.set_termios = imx_set_termios,
.type = imx_type,
.config_port = imx_config_port,
.verify_port = imx_verify_port,
#if defined(CONFIG_CONSOLE_POLL)
.poll_init = imx_poll_init,
.poll_get_char = imx_poll_get_char,
.poll_put_char = imx_poll_put_char,
#endif
};
static struct imx_port *imx_ports[UART_NR];
#ifdef CONFIG_SERIAL_IMX_CONSOLE
static void imx_console_putchar(struct uart_port *port, int ch)
{
struct imx_port *sport = (struct imx_port *)port;
while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
barrier();
writel(ch, sport->port.membase + URTX0);
}
/*
* Interrupts are disabled on entering
*/
static void
imx_console_write(struct console *co, const char *s, unsigned int count)
{
struct imx_port *sport = imx_ports[co->index];
struct imx_port_ucrs old_ucr;
unsigned int ucr1;
unsigned long flags = 0;
int locked = 1;
int retval;
retval = clk_enable(sport->clk_per);
if (retval)
return;
retval = clk_enable(sport->clk_ipg);
if (retval) {
clk_disable(sport->clk_per);
return;
}
if (sport->port.sysrq)
locked = 0;
else if (oops_in_progress)
locked = spin_trylock_irqsave(&sport->port.lock, flags);
else
spin_lock_irqsave(&sport->port.lock, flags);
/*
* First, save UCR1/2/3 and then disable interrupts
*/
imx_port_ucrs_save(&sport->port, &old_ucr);
ucr1 = old_ucr.ucr1;
if (is_imx1_uart(sport))
ucr1 |= IMX1_UCR1_UARTCLKEN;
ucr1 |= UCR1_UARTEN;
ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
writel(ucr1, sport->port.membase + UCR1);
writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
uart_console_write(&sport->port, s, count, imx_console_putchar);
/*
* Finally, wait for transmitter to become empty
* and restore UCR1/2/3
*/
while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
imx_port_ucrs_restore(&sport->port, &old_ucr);
if (locked)
spin_unlock_irqrestore(&sport->port.lock, flags);
clk_disable(sport->clk_ipg);
clk_disable(sport->clk_per);
}
/*
* If the port was already initialised (eg, by a boot loader),
* try to determine the current setup.
*/
static void __init
imx_console_get_options(struct imx_port *sport, int *baud,
int *parity, int *bits)
{
if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
/* ok, the port was enabled */
unsigned int ucr2, ubir, ubmr, uartclk;
unsigned int baud_raw;
unsigned int ucfr_rfdiv;
ucr2 = readl(sport->port.membase + UCR2);
*parity = 'n';
if (ucr2 & UCR2_PREN) {
if (ucr2 & UCR2_PROE)
*parity = 'o';
else
*parity = 'e';
}
if (ucr2 & UCR2_WS)
*bits = 8;
else
*bits = 7;
ubir = readl(sport->port.membase + UBIR) & 0xffff;
ubmr = readl(sport->port.membase + UBMR) & 0xffff;
ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
if (ucfr_rfdiv == 6)
ucfr_rfdiv = 7;
else
ucfr_rfdiv = 6 - ucfr_rfdiv;
uartclk = clk_get_rate(sport->clk_per);
uartclk /= ucfr_rfdiv;
{ /*
* The next code provides exact computation of
* baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
* without need of float support or long long division,
* which would be required to prevent 32bit arithmetic overflow
*/
unsigned int mul = ubir + 1;
unsigned int div = 16 * (ubmr + 1);
unsigned int rem = uartclk % div;
baud_raw = (uartclk / div) * mul;
baud_raw += (rem * mul + div / 2) / div;
*baud = (baud_raw + 50) / 100 * 100;
}
if (*baud != baud_raw)
pr_info("Console IMX rounded baud rate from %d to %d\n",
baud_raw, *baud);
}
}
static int __init
imx_console_setup(struct console *co, char *options)
{
struct imx_port *sport;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
int retval;
/*
* Check whether an invalid uart number has been specified, and
* if so, search for the first available port that does have
* console support.
*/
if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
co->index = 0;
sport = imx_ports[co->index];
if (sport == NULL)
return -ENODEV;
/* For setting the registers, we only need to enable the ipg clock. */
retval = clk_prepare_enable(sport->clk_ipg);
if (retval)
goto error_console;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
imx_console_get_options(sport, &baud, &parity, &bits);
imx_setup_ufcr(sport, 0);
retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
clk_disable(sport->clk_ipg);
if (retval) {
clk_unprepare(sport->clk_ipg);
goto error_console;
}
retval = clk_prepare(sport->clk_per);
if (retval)
clk_disable_unprepare(sport->clk_ipg);
error_console:
return retval;
}
static struct uart_driver imx_reg;
static struct console imx_console = {
.name = DEV_NAME,
.write = imx_console_write,
.device = uart_console_device,
.setup = imx_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &imx_reg,
};
#define IMX_CONSOLE &imx_console
#else
#define IMX_CONSOLE NULL
#endif
static struct uart_driver imx_reg = {
.owner = THIS_MODULE,
.driver_name = DRIVER_NAME,
.dev_name = DEV_NAME,
.major = SERIAL_IMX_MAJOR,
.minor = MINOR_START,
.nr = ARRAY_SIZE(imx_ports),
.cons = IMX_CONSOLE,
};
static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
{
struct imx_port *sport = platform_get_drvdata(dev);
unsigned int val;
/* enable wakeup from i.MX UART */
val = readl(sport->port.membase + UCR3);
val |= UCR3_AWAKEN;
writel(val, sport->port.membase + UCR3);
uart_suspend_port(&imx_reg, &sport->port);
return 0;
}
static int serial_imx_resume(struct platform_device *dev)
{
struct imx_port *sport = platform_get_drvdata(dev);
unsigned int val;
/* disable wakeup from i.MX UART */
val = readl(sport->port.membase + UCR3);
val &= ~UCR3_AWAKEN;
writel(val, sport->port.membase + UCR3);
uart_resume_port(&imx_reg, &sport->port);
return 0;
}
#ifdef CONFIG_OF
/*
* This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
* could successfully get all information from dt or a negative errno.
*/
static int serial_imx_probe_dt(struct imx_port *sport,
struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_id =
of_match_device(imx_uart_dt_ids, &pdev->dev);
int ret;
if (!np)
/* no device tree device */
return 1;
ret = of_alias_get_id(np, "serial");
if (ret < 0) {
dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
return ret;
}
sport->port.line = ret;
if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
sport->have_rtscts = 1;
if (of_get_property(np, "fsl,dte-mode", NULL))
sport->dte_mode = 1;
sport->devdata = of_id->data;
return 0;
}
#else
static inline int serial_imx_probe_dt(struct imx_port *sport,
struct platform_device *pdev)
{
return 1;
}
#endif
static void serial_imx_probe_pdata(struct imx_port *sport,
struct platform_device *pdev)
{
struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
sport->port.line = pdev->id;
sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
if (!pdata)
return;
if (pdata->flags & IMXUART_HAVE_RTSCTS)
sport->have_rtscts = 1;
}
static int serial_imx_probe(struct platform_device *pdev)
{
struct imx_port *sport;
void __iomem *base;
int ret = 0;
struct resource *res;
int txirq, rxirq, rtsirq;
sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
if (!sport)
return -ENOMEM;
ret = serial_imx_probe_dt(sport, pdev);
if (ret > 0)
serial_imx_probe_pdata(sport, pdev);
else if (ret < 0)
return ret;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
rxirq = platform_get_irq(pdev, 0);
txirq = platform_get_irq(pdev, 1);
rtsirq = platform_get_irq(pdev, 2);
sport->port.dev = &pdev->dev;
sport->port.mapbase = res->start;
sport->port.membase = base;
sport->port.type = PORT_IMX,
sport->port.iotype = UPIO_MEM;
sport->port.irq = rxirq;
sport->port.fifosize = 32;
sport->port.ops = &imx_pops;
sport->port.rs485_config = imx_rs485_config;
sport->port.rs485.flags =
SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX;
sport->port.flags = UPF_BOOT_AUTOCONF;
init_timer(&sport->timer);
sport->timer.function = imx_timeout;
sport->timer.data = (unsigned long)sport;
sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(sport->clk_ipg)) {
ret = PTR_ERR(sport->clk_ipg);
dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
return ret;
}
sport->clk_per = devm_clk_get(&pdev->dev, "per");
if (IS_ERR(sport->clk_per)) {
ret = PTR_ERR(sport->clk_per);
dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
return ret;
}
sport->port.uartclk = clk_get_rate(sport->clk_per);
/*
* Allocate the IRQ(s) i.MX1 has three interrupts whereas later
* chips only have one interrupt.
*/
if (txirq > 0) {
ret = devm_request_irq(&pdev->dev, rxirq, imx_rxint, 0,
dev_name(&pdev->dev), sport);
if (ret)
return ret;
ret = devm_request_irq(&pdev->dev, txirq, imx_txint, 0,
dev_name(&pdev->dev), sport);
if (ret)
return ret;
} else {
ret = devm_request_irq(&pdev->dev, rxirq, imx_int, 0,
dev_name(&pdev->dev), sport);
if (ret)
return ret;
}
imx_ports[sport->port.line] = sport;
platform_set_drvdata(pdev, sport);
return uart_add_one_port(&imx_reg, &sport->port);
}
static int serial_imx_remove(struct platform_device *pdev)
{
struct imx_port *sport = platform_get_drvdata(pdev);
return uart_remove_one_port(&imx_reg, &sport->port);
}
static struct platform_driver serial_imx_driver = {
.probe = serial_imx_probe,
.remove = serial_imx_remove,
.suspend = serial_imx_suspend,
.resume = serial_imx_resume,
.id_table = imx_uart_devtype,
.driver = {
.name = "imx-uart",
.of_match_table = imx_uart_dt_ids,
},
};
static int __init imx_serial_init(void)
{
int ret = uart_register_driver(&imx_reg);
if (ret)
return ret;
ret = platform_driver_register(&serial_imx_driver);
if (ret != 0)
uart_unregister_driver(&imx_reg);
return ret;
}
static void __exit imx_serial_exit(void)
{
platform_driver_unregister(&serial_imx_driver);
uart_unregister_driver(&imx_reg);
}
module_init(imx_serial_init);
module_exit(imx_serial_exit);
MODULE_AUTHOR("Sascha Hauer");
MODULE_DESCRIPTION("IMX generic serial port driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:imx-uart");
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