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linux-next/drivers/serial/imx.c
Marc Kleine-Budde 9fbe604456 imx serial: fix rts handling for non imx1 based hardware 
The interrupt handler for muxed interrupts (imx2/imx3) was calling
the rts handling subroutine if the RTSS bit was set.
(Which indicates the status of the RTS line), leading to an
interrupt flood on RTS bit low.

This patch fixes the problem by looking at the RTSD bit instead,
indicating a change in the RTS line.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2008-09-02 10:19:30 +02:00

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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 <linux/clk.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <mach/hardware.h>
#include <mach/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 */
#if defined CONFIG_ARCH_MX3 || defined CONFIG_ARCH_MX2
#define ONEMS 0xb0 /* One Millisecond register */
#define UTS 0xb4 /* UART Test Register */
#endif
#ifdef CONFIG_ARCH_IMX
#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 */
#endif
/* 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 */
#ifdef CONFIG_ARCH_IMX
#define UCR1_UARTCLKEN (1<<2) /* UART clock enabled */
#endif
#if defined CONFIG_ARCH_MX3 || defined CONFIG_ARCH_MX2
#define UCR1_UARTCLKEN (0) /* not present on mx2/mx3 */
#endif
#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 */
#ifdef CONFIG_ARCH_IMX
#define UCR3_REF25 (1<<3) /* Ref freq 25 MHz, only on mx1 */
#define UCR3_REF30 (1<<2) /* Ref Freq 30 MHz, only on mx1 */
#endif
#if defined CONFIG_ARCH_MX2 || defined CONFIG_ARCH_MX3
#define UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select, on mx2/mx3 */
#endif
#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 */
#ifdef CONFIG_ARCH_IMX
#define SERIAL_IMX_MAJOR 204
#define MINOR_START 41
#define DEV_NAME "ttySMX"
#define MAX_INTERNAL_IRQ IMX_IRQS
#endif
#if defined CONFIG_ARCH_MX3 || defined CONFIG_ARCH_MX2
#define SERIAL_IMX_MAJOR 207
#define MINOR_START 16
#define DEV_NAME "ttymxc"
#define MAX_INTERNAL_IRQ MXC_MAX_INT_LINES
#endif
/*
* 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
struct imx_port {
struct uart_port port;
struct timer_list timer;
unsigned int old_status;
int txirq,rxirq,rtsirq;
int have_rtscts:1;
struct clk *clk;
};
/*
* 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->port.tty;
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(temp | 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 (rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) ) {
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;
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
}
tty_insert_flip_char(tty, rx, flg);
}
out:
spin_unlock_irqrestore(&sport->port.lock,flags);
tty_flip_buffer_push(tty);
return IRQ_HANDLED;
}
static irqreturn_t imx_int(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
unsigned int sts;
sts = readl(sport->port.membase + USR1);
if (sts & USR1_RRDY)
imx_rxint(irq, dev_id);
if (sts & USR1_TRDY &&
readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
imx_txint(irq, dev_id);
if (sts & USR1_RTSD)
imx_rtsint(irq, dev_id);
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;
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 = (clk_get_rate(sport->clk) + 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(s) i.MX1 has three interrupts whereas later
* chips only have one interrupt.
*/
if (sport->txirq > 0) {
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 < MAX_INTERNAL_IRQ) ? 0 :
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
DRIVER_NAME, sport);
if (retval)
goto error_out3;
} else {
retval = request_irq(sport->port.irq, imx_int, 0,
DRIVER_NAME, sport);
if (retval) {
free_irq(sport->port.irq, sport);
goto error_out1;
}
}
/*
* Finally, clear and enable interrupts
*/
writel(USR1_RTSD, sport->port.membase + USR1);
temp = readl(sport->port.membase + UCR1);
temp |= 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);
#if defined CONFIG_ARCH_MX2 || defined CONFIG_ARCH_MX3
temp = readl(sport->port.membase + UCR3);
temp |= UCR3_RXDMUXSEL;
writel(temp, sport->port.membase + UCR3);
#endif
/*
* 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:
if (sport->txirq)
free_irq(sport->txirq, sport);
error_out2:
if (sport->rxirq)
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
*/
if (sport->txirq > 0) {
free_irq(sport->rtsirq, sport);
free_irq(sport->txirq, sport);
free_irq(sport->rxirq, sport);
} else
free_irq(sport->port.irq, 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;
unsigned int div, num, denom, ufcr;
/*
* 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, 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;
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);
div = sport->port.uartclk / (baud * 16);
if (div > 7)
div = 7;
if (!div)
div = 1;
num = baud;
denom = port->uartclk / div / 16;
/* shift num and denom right until they fit into 16 bits */
while (num > 0x10000 || denom > 0x10000) {
num >>= 1;
denom >>= 1;
}
if (num > 0)
num -= 1;
if (denom > 0)
denom -= 1;
writel(num, sport->port.membase + UBIR);
writel(denom, sport->port.membase + UBMR);
if (div == 7)
div = 6; /* 6 in RFDIV means divide by 7 */
else
div = 6 - div;
ufcr = readl(sport->port.membase + UFCR);
ufcr = (ufcr & (~UFCR_RFDIV)) |
(div << 7);
writel(ufcr, sport->port.membase + UFCR);
#ifdef ONEMS
writel(sport->port.uartclk / div / 1000, sport->port.membase + ONEMS);
#endif
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 platform_device *pdev = to_platform_device(port->dev);
struct resource *mmres;
mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(mmres->start, mmres->end - mmres->start + 1);
}
/*
* Request the memory region(s) being used by 'port'.
*/
static int imx_request_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
struct resource *mmres;
void *ret;
mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mmres)
return -ENODEV;
ret = request_mem_region(mmres->start, mmres->end - mmres->start + 1,
"imx-uart");
return ret ? 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[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) & 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 = clk_get_rate(sport->clk);
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 = 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);
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 *pdev)
{
struct imx_port *sport;
struct imxuart_platform_data *pdata;
void __iomem *base;
int ret = 0;
struct resource *res;
sport = kzalloc(sizeof(*sport), GFP_KERNEL);
if (!sport)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
ret = -ENODEV;
goto free;
}
base = ioremap(res->start, PAGE_SIZE);
if (!base) {
ret = -ENOMEM;
goto free;
}
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 = platform_get_irq(pdev, 0);
sport->rxirq = platform_get_irq(pdev, 0);
sport->txirq = platform_get_irq(pdev, 1);
sport->rtsirq = platform_get_irq(pdev, 2);
sport->port.fifosize = 32;
sport->port.ops = &imx_pops;
sport->port.flags = UPF_BOOT_AUTOCONF;
sport->port.line = pdev->id;
init_timer(&sport->timer);
sport->timer.function = imx_timeout;
sport->timer.data = (unsigned long)sport;
sport->clk = clk_get(&pdev->dev, "uart_clk");
if (IS_ERR(sport->clk)) {
ret = PTR_ERR(sport->clk);
goto unmap;
}
clk_enable(sport->clk);
sport->port.uartclk = clk_get_rate(sport->clk);
imx_ports[pdev->id] = sport;
pdata = pdev->dev.platform_data;
if(pdata && (pdata->flags & IMXUART_HAVE_RTSCTS))
sport->have_rtscts = 1;
if (pdata->init) {
ret = pdata->init(pdev);
if (ret)
goto clkput;
}
uart_add_one_port(&imx_reg, &sport->port);
platform_set_drvdata(pdev, &sport->port);
return 0;
clkput:
clk_put(sport->clk);
clk_disable(sport->clk);
unmap:
iounmap(sport->port.membase);
free:
kfree(sport);
return ret;
}
static int serial_imx_remove(struct platform_device *pdev)
{
struct imxuart_platform_data *pdata;
struct imx_port *sport = platform_get_drvdata(pdev);
pdata = pdev->dev.platform_data;
platform_set_drvdata(pdev, NULL);
if (sport) {
uart_remove_one_port(&imx_reg, &sport->port);
clk_put(sport->clk);
}
clk_disable(sport->clk);
if (pdata->exit)
pdata->exit(pdev);
iounmap(sport->port.membase);
kfree(sport);
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",
.owner = THIS_MODULE,
},
};
static int __init imx_serial_init(void)
{
int ret;
printk(KERN_INFO "Serial: IMX driver\n");
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");
MODULE_ALIAS("platform:imx-uart");
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