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linux/drivers/serial/imx.c

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/*
* linux/drivers/serial/imx.c
*
* Driver for Motorola 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* [29-Mar-2005] Mike Lee
* Added hardware handshake
*/
#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 <asm/io.h>
#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/arch/imx-uart.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 BIPR1 0xb0 /* Incremental Preset Register 1 */
#define BIPR2 0xb4 /* Incremental Preset Register 2 */
#define BIPR3 0xb8 /* Incremental Preset Register 3 */
#define BIPR4 0xbc /* Incremental Preset Register 4 */
#define BMPR1 0xc0 /* BRM Modulator Register 1 */
#define BMPR2 0xc4 /* BRM Modulator Register 2 */
#define BMPR3 0xc8 /* BRM Modulator Register 3 */
#define BMPR4 0xcc /* BRM Modulator Register 4 */
#define UTS 0xd0 /* UART Test Register */
/* UART Control Register Bit Fields.*/
#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 UCR1_ADEN (1<<15) /* Auto dectect 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_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 UCR1_UARTCLKEN (1<<2) /* UART clock enabled */
#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_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_TIMEOUTEN (1<<7) /* Timeout interrupt enable */
#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 UCR3_REF25 (1<<3) /* Ref freq 25 MHz */
#define UCR3_REF30 (1<<2) /* Ref Freq 30 MHz */
#define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
#define UCR3_BPEN (1<<0) /* Preset registers enable */
#define UCR4_CTSTL_32 (32<<10) /* CTS trigger level (32 chars) */
#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_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_RFDIV (7<<7) /* Reference freq divider mask */
#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 204
#define MINOR_START 41
#define NR_PORTS 2
#define IMX_ISR_PASS_LIMIT 256
/*
* This is the size of our serial port register set.
*/
#define UART_PORT_SIZE 0x100
/*
* 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"
struct imx_port {
struct uart_port port;
struct timer_list timer;
unsigned int old_status;
int txirq,rxirq,rtsirq;
int have_rtscts:1;
};
/*
* 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.info->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.info) {
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;
temp = readl(sport->port.membase + UCR1);
writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
}
/*
* interrupts disabled on entry
*/
static void imx_stop_rx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
temp = readl(sport->port.membase + UCR2);
writel(temp &~ UCR2_RXEN, sport->port.membase + UCR2);
}
/*
* 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 inline void imx_transmit_buffer(struct imx_port *sport)
{
struct circ_buf *xmit = &sport->port.info->xmit;
while (!(readl(sport->port.membase + UTS) & 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_empty(xmit))
break;
}
if (uart_circ_empty(xmit))
imx_stop_tx(&sport->port);
}
/*
* interrupts disabled on entry
*/
static void imx_start_tx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
temp = readl(sport->port.membase + UCR1);
writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
if (readl(sport->port.membase + UTS) & UTS_TXEMPTY)
imx_transmit_buffer(sport);
}
static irqreturn_t imx_rtsint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
unsigned int val = readl(sport->port.membase + USR1) & USR1_RTSS;
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
writel(USR1_RTSD, sport->port.membase + USR1);
uart_handle_cts_change(&sport->port, !!val);
wake_up_interruptible(&sport->port.info->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;
struct circ_buf *xmit = &sport->port.info->xmit;
unsigned long flags;
spin_lock_irqsave(&sport->port.lock,flags);
if (sport->port.x_char)
{
/* Send next char */
writel(sport->port.x_char, sport->port.membase + URTX0);
goto out;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
imx_stop_tx(&sport->port);
goto out;
}
imx_transmit_buffer(sport);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
out:
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_struct *tty = sport->port.info->tty;
unsigned long flags, temp;
rx = readl(sport->port.membase + URXD0);
spin_lock_irqsave(&sport->port.lock,flags);
do {
flg = TTY_NORMAL;
sport->port.icount.rx++;
temp = readl(sport->port.membase + USR2);
if( temp & USR2_BRCD ) {
writel(temp | USR2_BRCD, sport->port.membase + USR2);
if(uart_handle_break(&sport->port))
goto ignore_char;
}
if (uart_handle_sysrq_char
(&sport->port, (unsigned char)rx))
goto ignore_char;
if( rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) )
goto handle_error;
error_return:
tty_insert_flip_char(tty, rx, flg);
ignore_char:
rx = readl(sport->port.membase + URXD0);
} while(rx & URXD_CHARRDY);
out:
spin_unlock_irqrestore(&sport->port.lock,flags);
tty_flip_buffer_push(tty);
return IRQ_HANDLED;
handle_error:
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;
goto ignore_char;
}
rx &= sport->port.read_status_mask;
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
goto error_return;
}
/*
* 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;
return (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
}
/*
* 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;
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;
temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
if (mctrl & TIOCM_RTS)
temp |= UCR2_CTS;
writel(temp, sport->port.membase + UCR2);
}
/*
* 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;
unsigned int ufcr_rfdiv;
/* set receiver / transmitter trigger level.
* RFDIV is set such way to satisfy requested uartclk value
*/
val = TXTL << 10 | RXTL;
ufcr_rfdiv = (imx_get_perclk1() + sport->port.uartclk / 2) / sport->port.uartclk;
if(!ufcr_rfdiv)
ufcr_rfdiv = 1;
if(ufcr_rfdiv >= 7)
ufcr_rfdiv = 6;
else
ufcr_rfdiv = 6 - ufcr_rfdiv;
val |= UFCR_RFDIV & (ufcr_rfdiv << 7);
writel(val, sport->port.membase + UFCR);
return 0;
}
static int imx_startup(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
int retval;
unsigned long flags, temp;
imx_setup_ufcr(sport, 0);
/* disable the DREN bit (Data Ready interrupt enable) before
* requesting IRQs
*/
temp = readl(sport->port.membase + UCR4);
writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
/*
* Allocate the IRQ
*/
retval = request_irq(sport->rxirq, imx_rxint, 0,
DRIVER_NAME, sport);
if (retval) goto error_out1;
retval = request_irq(sport->txirq, imx_txint, 0,
DRIVER_NAME, sport);
if (retval) goto error_out2;
retval = request_irq(sport->rtsirq, imx_rtsint,
(sport->rtsirq < IMX_IRQS) ? 0 :
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
DRIVER_NAME, sport);
if (retval) goto error_out3;
/*
* Finally, clear and enable interrupts
*/
writel(USR1_RTSD, sport->port.membase + USR1);
temp = readl(sport->port.membase + UCR1);
temp |= (UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
writel(temp, sport->port.membase + UCR1);
temp = readl(sport->port.membase + UCR2);
temp |= (UCR2_RXEN | UCR2_TXEN);
writel(temp, sport->port.membase + UCR2);
/*
* Enable modem status interrupts
*/
spin_lock_irqsave(&sport->port.lock,flags);
imx_enable_ms(&sport->port);
spin_unlock_irqrestore(&sport->port.lock,flags);
return 0;
error_out3:
free_irq(sport->txirq, sport);
error_out2:
free_irq(sport->rxirq, sport);
error_out1:
return retval;
}
static void imx_shutdown(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long temp;
/*
* Stop our timer.
*/
del_timer_sync(&sport->timer);
/*
* Free the interrupts
*/
free_irq(sport->rtsirq, sport);
free_irq(sport->txirq, sport);
free_irq(sport->rxirq, sport);
/*
* Disable all interrupts, port and break condition.
*/
temp = readl(sport->port.membase + UCR1);
temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
writel(temp, sport->port.membase + UCR1);
}
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;
/*
* If we don't support modem control lines, don't allow
* these to be set.
*/
if (0) {
termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
termios->c_cflag |= CLOCAL;
}
/*
* 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;
ucr2 |= UCR2_CTSC;
} else {
termios->c_cflag &= ~CRTSCTS;
}
}
if (termios->c_cflag & CSTOPB)
ucr2 |= UCR2_STPB;
if (termios->c_cflag & PARENB) {
ucr2 |= UCR2_PREN;
if (termios->c_cflag & PARODD)
ucr2 |= UCR2_PROE;
}
/*
* Ask the core to calculate the divisor for us.
*/
baud = uart_get_baud_rate(port, termios, old, 0, 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;
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;
}
del_timer_sync(&sport->timer);
/*
* 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);
/* set the baud rate. We assume uartclk = 16 MHz
*
* baud * 16 UBIR - 1
* --------- = --------
* uartclk UBMR - 1
*/
writel((baud / 100) - 1, sport->port.membase + UBIR);
writel(10000 - 1, sport->port.membase + UBMR);
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;
}
/*
* Release the memory region(s) being used by 'port'.
*/
static void imx_release_port(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
release_mem_region(sport->port.mapbase, UART_PORT_SIZE);
}
/*
* Request the memory region(s) being used by 'port'.
*/
static int imx_request_port(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
"imx-uart") != NULL ? 0 : -EBUSY;
}
/*
* 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 &&
imx_request_port(&sport->port) == 0)
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 ((void *)sport->port.mapbase != ser->iomem_base)
ret = -EINVAL;
if (sport->port.iobase != ser->port)
ret = -EINVAL;
if (ser->hub6 != 0)
ret = -EINVAL;
return ret;
}
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,
.set_termios = imx_set_termios,
.type = imx_type,
.release_port = imx_release_port,
.request_port = imx_request_port,
.config_port = imx_config_port,
.verify_port = imx_verify_port,
};
static struct imx_port imx_ports[] = {
{
.txirq = UART1_MINT_TX,
.rxirq = UART1_MINT_RX,
.rtsirq = UART1_MINT_RTS,
.port = {
.type = PORT_IMX,
.iotype = UPIO_MEM,
.membase = (void *)IMX_UART1_BASE,
.mapbase = IMX_UART1_BASE, /* FIXME */
.irq = UART1_MINT_RX,
.uartclk = 16000000,
.fifosize = 32,
.flags = UPF_BOOT_AUTOCONF,
.ops = &imx_pops,
.line = 0,
},
}, {
.txirq = UART2_MINT_TX,
.rxirq = UART2_MINT_RX,
.rtsirq = UART2_MINT_RTS,
.port = {
.type = PORT_IMX,
.iotype = UPIO_MEM,
.membase = (void *)IMX_UART2_BASE,
.mapbase = IMX_UART2_BASE, /* FIXME */
.irq = UART2_MINT_RX,
.uartclk = 16000000,
.fifosize = 32,
.flags = UPF_BOOT_AUTOCONF,
.ops = &imx_pops,
.line = 1,
},
}
};
/*
* Setup the IMX serial ports.
* Note also that we support "console=ttySMXx" where "x" is either 0 or 1.
* Which serial port this ends up being depends on the machine you're
* running this kernel on. I'm not convinced that this is a good idea,
* but that's the way it traditionally works.
*
*/
static void __init imx_init_ports(void)
{
static int first = 1;
int i;
if (!first)
return;
first = 0;
for (i = 0; i < ARRAY_SIZE(imx_ports); i++) {
init_timer(&imx_ports[i].timer);
imx_ports[i].timer.function = imx_timeout;
imx_ports[i].timer.data = (unsigned long)&imx_ports[i];
}
}
#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) & 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];
unsigned int old_ucr1, old_ucr2;
/*
* First, save UCR1/2 and then disable interrupts
*/
old_ucr1 = readl(sport->port.membase + UCR1);
old_ucr2 = readl(sport->port.membase + UCR2);
writel((old_ucr1 | UCR1_UARTCLKEN | UCR1_UARTEN) &
~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
sport->port.membase + UCR1);
writel(old_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
*/
while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
writel(old_ucr1, sport->port.membase + UCR1);
writel(old_ucr2, sport->port.membase + UCR2);
}
/*
* 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 = imx_get_perclk1();
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)
printk(KERN_INFO "Serial: 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';
/*
* 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 (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
imx_console_get_options(sport, &baud, &parity, &bits);
imx_setup_ufcr(sport, 0);
return uart_set_options(&sport->port, co, baud, parity, bits, flow);
}
static struct uart_driver imx_reg;
static struct console imx_console = {
.name = "ttySMX",
.write = imx_console_write,
.device = uart_console_device,
.setup = imx_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &imx_reg,
};
static int __init imx_rs_console_init(void)
{
imx_init_ports();
register_console(&imx_console);
return 0;
}
console_initcall(imx_rs_console_init);
#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 = "ttySMX",
.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);
if (sport)
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);
if (sport)
uart_resume_port(&imx_reg, &sport->port);
return 0;
}
static int serial_imx_probe(struct platform_device *dev)
{
struct imxuart_platform_data *pdata;
imx_ports[dev->id].port.dev = &dev->dev;
pdata = (struct imxuart_platform_data *)dev->dev.platform_data;
if(pdata && (pdata->flags & IMXUART_HAVE_RTSCTS))
imx_ports[dev->id].have_rtscts = 1;
uart_add_one_port(&imx_reg, &imx_ports[dev->id].port);
platform_set_drvdata(dev, &imx_ports[dev->id]);
return 0;
}
static int serial_imx_remove(struct platform_device *dev)
{
struct imx_port *sport = platform_get_drvdata(dev);
platform_set_drvdata(dev, NULL);
if (sport)
uart_remove_one_port(&imx_reg, &sport->port);
return 0;
}
static struct platform_driver serial_imx_driver = {
.probe = serial_imx_probe,
.remove = serial_imx_remove,
.suspend = serial_imx_suspend,
.resume = serial_imx_resume,
.driver = {
.name = "imx-uart",
},
};
static int __init imx_serial_init(void)
{
int ret;
printk(KERN_INFO "Serial: IMX driver\n");
imx_init_ports();
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 0;
}
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");
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