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linux/drivers/tty/serial/imx.c
Uwe Kleine-König 58362d5be3 serial: imx: implement handshaking using gpios with the mctrl_gpio helper 
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-13 20:01:47 -08:00

2231 lines
58 KiB
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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>
#include "serial_mctrl_gpio.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_AGTIM (1<<8) /* Ageing timer interrupt 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_RIDELT (1<<10) /* Ring Interrupt Delta */
#define USR2_RIIN (1<<9) /* Ring Indicator Input */
#define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
#define USR2_WAKE (1<<7) /* Wake */
#define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
#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;
struct mctrl_gpios *gpios;
/* 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;
unsigned int saved_reg[10];
bool context_saved;
};
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 const 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
static void imx_port_rts_active(struct imx_port *sport, unsigned long *ucr2)
{
*ucr2 &= ~UCR2_CTSC;
*ucr2 |= UCR2_CTS;
mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
}
static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2)
{
*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
}
static void imx_port_rts_auto(struct imx_port *sport, unsigned long *ucr2)
{
*ucr2 |= UCR2_CTSC;
}
/*
* 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)
imx_port_rts_inactive(sport, &temp);
else
imx_port_rts_active(sport, &temp);
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);
mctrl_gpio_enable_ms(sport->gpios);
}
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) {
temp = readl(port->membase + UCR2);
if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
imx_port_rts_inactive(sport, &temp);
else
imx_port_rts_active(sport, &temp);
writel(temp, port->membase + UCR2);
/* enable transmitter and shifter empty irq */
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;
if (tty_insert_flip_char(port, rx, flg) == 0)
sport->port.icount.buf_overrun++;
}
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 receiver ready and aging timer interrupts */
temp = readl(sport->port.membase + UCR1);
temp &= ~(UCR1_RRDYEN);
writel(temp, sport->port.membase + UCR1);
temp = readl(sport->port.membase + UCR2);
temp &= ~(UCR2_ATEN);
writel(temp, sport->port.membase + UCR2);
/* 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 | USR1_AGTIM)) {
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) {
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_hwmctrl(struct imx_port *sport)
{
unsigned int tmp = TIOCM_DSR;
unsigned usr1 = readl(sport->port.membase + USR1);
if (usr1 & USR1_RTSS)
tmp |= TIOCM_CTS;
/* in DCE mode DCDIN is always 0 */
if (!(usr1 & USR2_DCDIN))
tmp |= TIOCM_CAR;
/* in DCE mode RIIN is always 0 */
if (readl(sport->port.membase + USR2) & USR2_RIIN)
tmp |= TIOCM_RI;
return tmp;
}
static unsigned int imx_get_mctrl(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned int ret = imx_get_hwmctrl(sport);
mctrl_gpio_get(sport->gpios, &ret);
return ret;
}
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 + UCR3) & ~UCR3_DSR;
if (!(mctrl & TIOCM_DTR))
temp |= UCR3_DSR;
writel(temp, sport->port.membase + UCR3);
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));
mctrl_gpio_set(sport->gpios, mctrl);
}
/*
* 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);
}
/*
* 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 = imx_get_hwmctrl(sport);
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);
}
}
#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);
/* re-enable interrupts to get notified when new symbols are incoming */
temp = readl(sport->port.membase + UCR1);
temp |= UCR1_RRDYEN;
writel(temp, sport->port.membase + UCR1);
temp = readl(sport->port.membase + UCR2);
temp |= UCR2_ATEN;
writel(temp, sport->port.membase + UCR2);
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 two kinds of RX DMA interrupts(such as in the MX6Q):
* [1] the RX DMA buffer is full.
* [2] the aging timer expires
*
* Condition [2] is triggered when a character has been sitting in the FIFO
* for at least 8 byte durations.
*/
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;
dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
if (count) {
if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
int bytes = tty_insert_flip_string(port, sport->rx_buf,
count);
if (bytes != count)
sport->port.icount.buf_overrun++;
}
tty_flip_buffer_push(port);
sport->port.icount.rx += count;
}
/*
* Restart RX DMA directly if more data is available in order to skip
* the roundtrip through the IRQ handler. If there is some data already
* in the FIFO, DMA needs to be restarted soon anyways.
*
* Otherwise stop the DMA and reactivate FIFO IRQs to restart DMA once
* data starts to arrive again.
*/
if (readl(sport->port.membase + USR2) & USR2_RDR)
start_rx_dma(sport);
else
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;
}
#define TXTL_DEFAULT 2 /* reset default */
#define RXTL_DEFAULT 1 /* reset default */
#define TXTL_DMA 8 /* DMA burst setting */
#define RXTL_DMA 9 /* DMA burst setting */
static void imx_setup_ufcr(struct imx_port *sport,
unsigned char txwl, unsigned char rxwl)
{
unsigned int val;
/* set receiver / transmitter trigger level */
val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
val |= txwl << UFCR_TXTL_SHF | rxwl;
writel(val, sport->port.membase + UFCR);
}
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;
/* one byte less than the watermark level to enable the aging timer */
slave_config.src_maxburst = RXTL_DMA - 1;
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_DMA;
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;
writel(temp, sport->port.membase + UCR1);
temp = readl(sport->port.membase + UCR2);
temp |= UCR2_ATEN;
writel(temp, sport->port.membase + UCR2);
imx_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
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 | UCR2_ATEN);
writel(temp, sport->port.membase + UCR2);
imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
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, TXTL_DEFAULT, RXTL_DEFAULT);
/* 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);
/* 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);
/* 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);
/*
* 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);
}
mctrl_gpio_disable_ms(sport->gpios);
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 long ucr2, old_ucr1, old_ucr2;
unsigned int baud, quot;
unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
unsigned long 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)
imx_port_rts_inactive(sport, &ucr2);
else
imx_port_rts_active(sport, &ucr2);
} else {
imx_port_rts_auto(sport, &ucr2);
}
} else {
termios->c_cflag &= ~CRTSCTS;
}
} else if (port->rs485.flags & SER_RS485_ENABLED) {
/* disable transmitter */
if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
imx_port_rts_inactive(sport, &ucr2);
else
imx_port_rts_active(sport, &ucr2);
}
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_ucr2 = readl(sport->port.membase + UCR2);
writel(old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN),
sport->port.membase + UCR2);
old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
/* 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_ucr2, 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, TXTL_DEFAULT, RXTL_DEFAULT);
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);
if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
imx_port_rts_inactive(sport, &temp);
else
imx_port_rts_active(sport, &temp);
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, TXTL_DEFAULT, RXTL_DEFAULT);
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
#ifdef CONFIG_OF
static void imx_console_early_putchar(struct uart_port *port, int ch)
{
while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL)
cpu_relax();
writel_relaxed(ch, port->membase + URTX0);
}
static void imx_console_early_write(struct console *con, const char *s,
unsigned count)
{
struct earlycon_device *dev = con->data;
uart_console_write(&dev->port, s, count, imx_console_early_putchar);
}
static int __init
imx_console_early_setup(struct earlycon_device *dev, const char *opt)
{
if (!dev->port.membase)
return -ENODEV;
dev->con->write = imx_console_early_write;
return 0;
}
OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
#endif
#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,
};
#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;
int ret;
sport->devdata = of_device_get_match_data(&pdev->dev);
if (!sport->devdata)
/* 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;
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, reg;
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->gpios = mctrl_gpio_init(&sport->port, 0);
if (IS_ERR(sport->gpios))
return PTR_ERR(sport->gpios);
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);
/* For register access, we only need to enable the ipg clock. */
ret = clk_prepare_enable(sport->clk_ipg);
if (ret)
return ret;
/* Disable interrupts before requesting them */
reg = readl_relaxed(sport->port.membase + UCR1);
reg &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
UCR1_TXMPTYEN | UCR1_RTSDEN);
writel_relaxed(reg, sport->port.membase + UCR1);
clk_disable_unprepare(sport->clk_ipg);
/*
* 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 void serial_imx_restore_context(struct imx_port *sport)
{
if (!sport->context_saved)
return;
writel(sport->saved_reg[4], sport->port.membase + UFCR);
writel(sport->saved_reg[5], sport->port.membase + UESC);
writel(sport->saved_reg[6], sport->port.membase + UTIM);
writel(sport->saved_reg[7], sport->port.membase + UBIR);
writel(sport->saved_reg[8], sport->port.membase + UBMR);
writel(sport->saved_reg[9], sport->port.membase + IMX21_UTS);
writel(sport->saved_reg[0], sport->port.membase + UCR1);
writel(sport->saved_reg[1] | UCR2_SRST, sport->port.membase + UCR2);
writel(sport->saved_reg[2], sport->port.membase + UCR3);
writel(sport->saved_reg[3], sport->port.membase + UCR4);
sport->context_saved = false;
}
static void serial_imx_save_context(struct imx_port *sport)
{
/* Save necessary regs */
sport->saved_reg[0] = readl(sport->port.membase + UCR1);
sport->saved_reg[1] = readl(sport->port.membase + UCR2);
sport->saved_reg[2] = readl(sport->port.membase + UCR3);
sport->saved_reg[3] = readl(sport->port.membase + UCR4);
sport->saved_reg[4] = readl(sport->port.membase + UFCR);
sport->saved_reg[5] = readl(sport->port.membase + UESC);
sport->saved_reg[6] = readl(sport->port.membase + UTIM);
sport->saved_reg[7] = readl(sport->port.membase + UBIR);
sport->saved_reg[8] = readl(sport->port.membase + UBMR);
sport->saved_reg[9] = readl(sport->port.membase + IMX21_UTS);
sport->context_saved = true;
}
static void serial_imx_enable_wakeup(struct imx_port *sport, bool on)
{
unsigned int val;
val = readl(sport->port.membase + UCR3);
if (on)
val |= UCR3_AWAKEN;
else
val &= ~UCR3_AWAKEN;
writel(val, sport->port.membase + UCR3);
val = readl(sport->port.membase + UCR1);
if (on)
val |= UCR1_RTSDEN;
else
val &= ~UCR1_RTSDEN;
writel(val, sport->port.membase + UCR1);
}
static int imx_serial_port_suspend_noirq(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct imx_port *sport = platform_get_drvdata(pdev);
int ret;
ret = clk_enable(sport->clk_ipg);
if (ret)
return ret;
serial_imx_save_context(sport);
clk_disable(sport->clk_ipg);
return 0;
}
static int imx_serial_port_resume_noirq(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct imx_port *sport = platform_get_drvdata(pdev);
int ret;
ret = clk_enable(sport->clk_ipg);
if (ret)
return ret;
serial_imx_restore_context(sport);
clk_disable(sport->clk_ipg);
return 0;
}
static int imx_serial_port_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct imx_port *sport = platform_get_drvdata(pdev);
/* enable wakeup from i.MX UART */
serial_imx_enable_wakeup(sport, true);
uart_suspend_port(&imx_reg, &sport->port);
return 0;
}
static int imx_serial_port_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct imx_port *sport = platform_get_drvdata(pdev);
/* disable wakeup from i.MX UART */
serial_imx_enable_wakeup(sport, false);
uart_resume_port(&imx_reg, &sport->port);
return 0;
}
static const struct dev_pm_ops imx_serial_port_pm_ops = {
.suspend_noirq = imx_serial_port_suspend_noirq,
.resume_noirq = imx_serial_port_resume_noirq,
.suspend = imx_serial_port_suspend,
.resume = imx_serial_port_resume,
};
static struct platform_driver serial_imx_driver = {
.probe = serial_imx_probe,
.remove = serial_imx_remove,
.id_table = imx_uart_devtype,
.driver = {
.name = "imx-uart",
.of_match_table = imx_uart_dt_ids,
.pm = &imx_serial_port_pm_ops,
},
};
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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