Re: [RFC][PATCH 1/1] serial: OMAP driver

[Tony Lindgren <tony@atomide.com>]

Hi,

Some comments below.

* Girish. S. G. <girishsg@ti.com> [080731 14:26]:
> Serial driver for OMAP Uart controllers
> 
> Signed-off-by: Girish S G <girishsg@ti.com>
> ---
>  arch/arm/configs/omap_3430sdp_defconfig |   12
>  arch/arm/mach-omap2/serial.c            |  166 ++---
>  drivers/serial/Kconfig                  |   23
>  drivers/serial/Makefile                 |    1
>  drivers/serial/omap-serial.c            |  887 ++++++++++++++++++++++++++++++++
>  include/linux/serial_core.h             |    3
>  6 files changed, 974 insertions(+), 118 deletions(-)
> 
> Index: linux-omap-2.6/arch/arm/configs/omap_3430sdp_defconfig
> ===================================================================
> --- linux-omap-2.6.orig/arch/arm/configs/omap_3430sdp_defconfig	2008-07-31
> 11:15:29.000000000 +0530
> +++ linux-omap-2.6/arch/arm/configs/omap_3430sdp_defconfig	2008-07-31
> 11:25:24.000000000 +0530
> @@ -683,19 +683,13 @@
>  #
>  # Serial drivers
>  #
> -CONFIG_SERIAL_8250=y
> -CONFIG_SERIAL_8250_CONSOLE=y
> -CONFIG_SERIAL_8250_NR_UARTS=32
> -CONFIG_SERIAL_8250_RUNTIME_UARTS=4
> -CONFIG_SERIAL_8250_EXTENDED=y
> -CONFIG_SERIAL_8250_MANY_PORTS=y
> -CONFIG_SERIAL_8250_SHARE_IRQ=y
> -CONFIG_SERIAL_8250_DETECT_IRQ=y
> -CONFIG_SERIAL_8250_RSA=y
> +# CONFIG_SERIAL_8250 is not set
> 
>  #
>  # Non-8250 serial port support
>  #
> +CONFIG_SERIAL_OMAP=y
> +CONFIG_SERIAL_OMAP_CONSOLE=y
>  CONFIG_SERIAL_CORE=y
>  CONFIG_SERIAL_CORE_CONSOLE=y
>  CONFIG_UNIX98_PTYS=y
> Index: linux-omap-2.6/arch/arm/mach-omap2/serial.c
> ===================================================================
> --- linux-omap-2.6.orig/arch/arm/mach-omap2/serial.c	2008-07-31
> 11:15:29.000000000 +0530
> +++ linux-omap-2.6/arch/arm/mach-omap2/serial.c	2008-07-31 16:33:53.000000000
> +0530
> @@ -14,94 +14,75 @@
>   */
>  #include <linux/kernel.h>
>  #include <linux/init.h>
> -#include <linux/serial_8250.h>
>  #include <linux/serial_reg.h>
> +#include <linux/platform_device.h>
> +#include <linux/serial.h>
>  #include <linux/clk.h>
> 
>  #include <linux/io.h>
> 
> -#include <asm/arch/common.h>
>  #include <asm/arch/board.h>
> 
> -static struct clk *uart_ick[OMAP_MAX_NR_PORTS];
> -static struct clk *uart_fck[OMAP_MAX_NR_PORTS];
> -
> -static struct plat_serial8250_port serial_platform_data[] = {
> +static struct resource omap2_uart1_resources[] = {
>  	{
> -		.membase	= (__force void __iomem *)IO_ADDRESS(OMAP_UART1_BASE),
> -		.mapbase	= (unsigned long)OMAP_UART1_BASE,
> -		.irq		= 72,
> -		.flags		= UPF_BOOT_AUTOCONF,
> -		.iotype		= UPIO_MEM,
> -		.regshift	= 2,
> -		.uartclk	= OMAP24XX_BASE_BAUD * 16,
> -	}, {
> -		.membase	= (__force void __iomem *)IO_ADDRESS(OMAP_UART2_BASE),
> -		.mapbase	= (unsigned long)OMAP_UART2_BASE,
> -		.irq		= 73,
> -		.flags		= UPF_BOOT_AUTOCONF,
> -		.iotype		= UPIO_MEM,
> -		.regshift	= 2,
> -		.uartclk	= OMAP24XX_BASE_BAUD * 16,
> -	}, {
> -		.membase	= (__force void __iomem *)IO_ADDRESS(OMAP_UART3_BASE),
> -		.mapbase	= (unsigned long)OMAP_UART3_BASE,
> -		.irq		= 74,
> -		.flags		= UPF_BOOT_AUTOCONF,
> -		.iotype		= UPIO_MEM,
> -		.regshift	= 2,
> -		.uartclk	= OMAP24XX_BASE_BAUD * 16,
> +		.start		= OMAP_UART1_BASE,
> +		.end		= OMAP_UART1_BASE + 0x3ff,
> +		.flags		= IORESOURCE_MEM,
>  	}, {
> -		.flags		= 0
> +		.start		= 72,
> +		.flags		= IORESOURCE_IRQ,
>  	}
>  };
> 
> -static inline unsigned int serial_read_reg(struct plat_serial8250_port *up,
> -					   int offset)
> -{
> -	offset <<= up->regshift;
> -	return (unsigned int)__raw_readb(up->membase + offset);
> -}
> -
> -static inline void serial_write_reg(struct plat_serial8250_port *p, int offset,
> -				    int value)
> -{
> -	offset <<= p->regshift;
> -	__raw_writeb(value, p->membase + offset);
> -}
> -
> -/*
> - * Internal UARTs need to be initialized for the 8250 autoconfig to work
> - * properly. Note that the TX watermark initialization may not be needed
> - * once the 8250.c watermark handling code is merged.
> - */
> -static inline void __init omap_serial_reset(struct plat_serial8250_port *p)
> -{
> -	serial_write_reg(p, UART_OMAP_MDR1, 0x07);
> -	serial_write_reg(p, UART_OMAP_SCR, 0x08);
> -	serial_write_reg(p, UART_OMAP_MDR1, 0x00);
> -	serial_write_reg(p, UART_OMAP_SYSC, (0x02 << 3) | (1 << 2) | (1 << 0));
> -}
> +static struct resource omap2_uart2_resources[] = {
> +	{
> +		.start		= OMAP_UART2_BASE,
> +		.end		= OMAP_UART2_BASE + 0x3ff,
> +		.flags		= IORESOURCE_MEM,
> +	}, {
> +		.start		= 73,
> +		.flags		= IORESOURCE_IRQ,
> +	}
> +};
> 
> -void omap_serial_enable_clocks(int enable)
> -{
> -	int i;
> -	for (i = 0; i < OMAP_MAX_NR_PORTS; i++) {
> -		if (uart_ick[i] && uart_fck[i]) {
> -			if (enable) {
> -				clk_enable(uart_ick[i]);
> -				clk_enable(uart_fck[i]);
> -			} else {
> -				clk_disable(uart_ick[i]);
> -				clk_disable(uart_fck[i]);
> -			}
> -		}
> +static struct resource omap2_uart3_resources[] = {
> +	{
> +		.start		= OMAP_UART3_BASE,
> +		.end		= OMAP_UART3_BASE + 0x3ff,
> +		.flags		= IORESOURCE_MEM,
> +	}, {
> +		.start		= 74,
> +		.flags		= IORESOURCE_IRQ,
>  	}
> -}
> +};
> +static struct platform_device uart1_device = {
> +	.name			= "omap-uart",
> +	.id			= 1,
> +	.num_resources		= ARRAY_SIZE(omap2_uart1_resources),
> +	.resource		= omap2_uart1_resources,
> +};
> +static struct platform_device uart2_device = {
> +	.name			= "omap-uart",
> +	.id			= 2,
> +	.num_resources		= ARRAY_SIZE(omap2_uart2_resources),
> +	.resource		= omap2_uart2_resources,
> +};
> +static struct platform_device uart3_device = {
> +	.name			= "omap-uart",
> +	.id			= 3,
> +	.num_resources		= ARRAY_SIZE(omap2_uart3_resources),
> +	.resource		= omap2_uart3_resources,
> +};
> +
> +static struct platform_device *uart_devices[] = {
> +	&uart1_device,
> +	&uart2_device,
> +	&uart3_device
> +};
> 
>  void __init omap_serial_init(void)
>  {
> -	int i;
> +	int i, r;
>  	const struct omap_uart_config *info;
>  	char name[16];
> 
> @@ -116,45 +97,12 @@
>  	if (info == NULL)
>  		return;
> 
> -	for (i = 0; i < OMAP_MAX_NR_PORTS; i++) {
> -		struct plat_serial8250_port *p = serial_platform_data + i;
> -
> -		if (!(info->enabled_uarts & (1 << i))) {
> -			p->membase = NULL;
> -			p->mapbase = 0;
> +	for (i = 0; i < ARRAY_SIZE(uart_devices); i++) {
> +		if (!(info->enabled_uarts & (1 << i)))
>  			continue;
> -		}
> -
> -		sprintf(name, "uart%d_ick", i+1);
> -		uart_ick[i] = clk_get(NULL, name);
> -		if (IS_ERR(uart_ick[i])) {
> -			printk(KERN_ERR "Could not get uart%d_ick\n", i+1);
> -			uart_ick[i] = NULL;
> -		} else
> -			clk_enable(uart_ick[i]);
> -
> -		sprintf(name, "uart%d_fck", i+1);
> -		uart_fck[i] = clk_get(NULL, name);
> -		if (IS_ERR(uart_fck[i])) {
> -			printk(KERN_ERR "Could not get uart%d_fck\n", i+1);
> -			uart_fck[i] = NULL;
> -		} else
> -			clk_enable(uart_fck[i]);
> -
> -		omap_serial_reset(p);
> +		r = platform_device_register(uart_devices[i]);
> +		if (r < 0)
> +			printk(KERN_ERR "Failed to register UART%d\n", i + 1);
>  	}
> -}
> -
> -static struct platform_device serial_device = {
> -	.name			= "serial8250",
> -	.id			= PLAT8250_DEV_PLATFORM,
> -	.dev			= {
> -		.platform_data	= serial_platform_data,
> -	},
> -};

What about powering UART on/off? I suggest you provide set_power()
function in platform_data. That way the UART power function can be
generic on later omaps, or external like the FPGA on omap1510.


> 
> -static int __init omap_init(void)
> -{
> -	return platform_device_register(&serial_device);
>  }
> -arch_initcall(omap_init);
> Index: linux-omap-2.6/drivers/serial/Kconfig
> ===================================================================
> --- linux-omap-2.6.orig/drivers/serial/Kconfig	2008-07-31 11:16:07.000000000 +0530
> +++ linux-omap-2.6/drivers/serial/Kconfig	2008-07-31 11:25:24.000000000 +0530
> @@ -592,6 +592,29 @@
>  	  your boot loader (lilo or loadlin) about how to pass options to the
>  	  kernel at boot time.)
> 
> +config SERIAL_OMAP
> +	bool "OMAP serial port support"
> +	depends on ARM && ARCH_OMAP
> +	select SERIAL_CORE
> +	help
> +	  If you have a machine based on an Texas Instruments OMAP CPU you
> +	  can enable its onboard serial ports by enabling this option.
> +
> +config SERIAL_OMAP_CONSOLE
> +	bool "Console on OMAP serial port"
> +	depends on SERIAL_OMAP
> +	select SERIAL_CORE_CONSOLE
> +	help
> +	  If you have enabled the serial port on the Texas Instruments OMAP
> +	  CPU you can make it the console by answering Y to this option.
> +
> +	  Even if you say Y here, the currently visible virtual console
> +	  (/dev/tty0) will still be used as the system console by default, but
> +	  you can alter that using a kernel command line option such as
> +	  "console=ttyS0". (Try "man bootparam" or see the documentation of
> +	  your boot loader (lilo or loadlin) about how to pass options to the
> +	  kernel at boot time.)
> +
>  config SERIAL_SA1100
>  	bool "SA1100 serial port support"
>  	depends on ARM && ARCH_SA1100
> Index: linux-omap-2.6/drivers/serial/Makefile
> ===================================================================
> --- linux-omap-2.6.orig/drivers/serial/Makefile	2008-07-31 11:16:07.000000000
> +0530
> +++ linux-omap-2.6/drivers/serial/Makefile	2008-07-31 11:25:24.000000000 +0530
> @@ -24,6 +24,7 @@
>  obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o
>  obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o
>  obj-$(CONFIG_SERIAL_PXA) += pxa.o
> +obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
>  obj-$(CONFIG_SERIAL_PNX8XXX) += pnx8xxx_uart.o
>  obj-$(CONFIG_SERIAL_SA1100) += sa1100.o
>  obj-$(CONFIG_SERIAL_BFIN) += bfin_5xx.o
> Index: linux-omap-2.6/drivers/serial/omap-serial.c
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-omap-2.6/drivers/serial/omap-serial.c	2008-07-31 16:34:16.000000000
> +0530
> @@ -0,0 +1,887 @@
> +/*
> + *  linux/drivers/serial/omap-serial.c
> + *
> + *
> + *  Modified: Girish S G
> + *  Copyright (C) 2008 Texas Instrument Inc.
> + *
> + *  Initial driver: Juha Yrjola
> + *  Copyright (C) 2007 Nokia Corporation
> + *
> + *  Based on drivers/serial/pxa.c by Nicolas Pitre.
> + *  Copyright (C) 2003 Monta Vista Software, Inc.
> + *
> + * 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.
> + *
> + */
> +
> +#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
> +#define SUPPORT_SYSRQ
> +#endif
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/console.h>
> +#include <linux/sysrq.h>
> +#include <linux/serial_reg.h>
> +#include <linux/circ_buf.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +#include <linux/serial_core.h>
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +
> +#include <asm/hardware.h>
> +#include <asm/irq.h>
> +
> +struct uart_omap_port {
> +	struct uart_port	port;
> +	int			shift;
> +	struct clk		*iclk, *fclk;
> +
> +	struct platform_device	*pdev;
> +
> +	unsigned char		ier;
> +	unsigned char		lcr;
> +	unsigned char		mcr;
> +	unsigned int		lsr_break_flag;
> +	char			name[12];
> +};
> +
> +static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
> +{
> +	offset <<= up->shift;
> +	return readb(up->port.membase + offset);
> +}
> +
> +static inline void serial_out(struct uart_omap_port *up, int offset, int value)
> +{
> +	offset <<= up->shift;
> +	writeb(value, up->port.membase + offset);
> +}
> +
> +static void enable_uart_clocks(struct uart_omap_port *up)
> +{
> +	clk_enable(up->fclk);
> +	if (up->iclk != NULL)
> +		clk_enable(up->iclk);
> +}
> +
> +static void disable_uart_clocks(struct uart_omap_port *up)
> +{
> +	clk_disable(up->fclk);
> +	if (up->iclk != NULL)
> +		clk_disable(up->iclk);
> +}
> +
> +static void serial_omap_enable_ms(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +
> +	up->ier |= UART_IER_MSI;
> +	serial_out(up, UART_IER, up->ier);
> +}
> +
> +static void serial_omap_stop_tx(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +
> +	if (up->ier & UART_IER_THRI) {
> +		up->ier &= ~UART_IER_THRI;
> +		serial_out(up, UART_IER, up->ier);
> +	}
> +}
> +
> +static void serial_omap_stop_rx(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +
> +	up->ier &= ~UART_IER_RLSI;
> +	up->port.read_status_mask &= ~UART_LSR_DR;
> +	serial_out(up, UART_IER, up->ier);
> +}
> +
> +static inline void receive_chars(struct uart_omap_port *up, int *status)
> +{
> +	struct tty_struct *tty = up->port.info->tty;
> +	unsigned int ch, flag;
> +	int max_count = 256;
> +
> +	do {
> +		ch = serial_in(up, UART_RX);
> +		flag = TTY_NORMAL;
> +		up->port.icount.rx++;
> +
> +		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
> +				       UART_LSR_FE | UART_LSR_OE))) {
> +			/*
> +			 * For statistics only
> +			 */
> +			if (*status & UART_LSR_BI) {
> +				*status &= ~(UART_LSR_FE | UART_LSR_PE);
> +				up->port.icount.brk++;
> +				/*
> +				 * We do the SysRQ and SAK checking
> +				 * here because otherwise the break
> +				 * may get masked by ignore_status_mask
> +				 * or read_status_mask.
> +				 */
> +				if (uart_handle_break(&up->port))
> +					goto ignore_char;
> +			} else if (*status & UART_LSR_PE)
> +				up->port.icount.parity++;
> +			else if (*status & UART_LSR_FE)
> +				up->port.icount.frame++;
> +			if (*status & UART_LSR_OE)
> +				up->port.icount.overrun++;
> +
> +			/*
> +			 * Mask off conditions which should be ignored.
> +			 */
> +			*status &= up->port.read_status_mask;
> +
> +#ifdef CONFIG_SERIAL_OMAP_CONSOLE
> +			if (up->port.line == up->port.cons->index) {
> +				/* Recover the break flag from console xmit */
> +				*status |= up->lsr_break_flag;
> +				up->lsr_break_flag = 0;
> +			}
> +#endif
> +			if (*status & UART_LSR_BI)
> +				flag = TTY_BREAK;
> +			else if (*status & UART_LSR_PE)
> +				flag = TTY_PARITY;
> +			else if (*status & UART_LSR_FE)
> +				flag = TTY_FRAME;
> +		}
> +
> +		if (uart_handle_sysrq_char(&up->port, ch))
> +			goto ignore_char;
> +
> +		uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
> +
> +ignore_char:
> +		*status = serial_in(up, UART_LSR);
> +	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
> +	tty_flip_buffer_push(tty);
> +}
> +
> +static void transmit_chars(struct uart_omap_port *up)
> +{
> +	struct circ_buf *xmit = &up->port.info->xmit;
> +	int count;
> +
> +	if (up->port.x_char) {
> +		serial_out(up, UART_TX, up->port.x_char);
> +		up->port.icount.tx++;
> +		up->port.x_char = 0;
> +		return;
> +	}
> +	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
> +		serial_omap_stop_tx(&up->port);
> +		return;
> +	}
> +
> +	count = 16;
> +	do {
> +		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
> +		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
> +		up->port.icount.tx++;
> +		if (uart_circ_empty(xmit))
> +			break;
> +	} while (--count > 0);
> +
> +	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
> +		uart_write_wakeup(&up->port);
> +
> +	if (uart_circ_empty(xmit))
> +		serial_omap_stop_tx(&up->port);
> +}
> +
> +static void serial_omap_start_tx(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +
> +	if (!(up->ier & UART_IER_THRI)) {
> +		up->ier |= UART_IER_THRI;
> +		serial_out(up, UART_IER, up->ier);
> +	}
> +}
> +
> +static inline void check_modem_status(struct uart_omap_port *up)
> +{
> +	int status;
> +
> +	status = serial_in(up, UART_MSR);
> +
> +	if ((status & UART_MSR_ANY_DELTA) == 0)
> +		return;
> +
> +	if (status & UART_MSR_TERI)
> +		up->port.icount.rng++;
> +	if (status & UART_MSR_DDSR)
> +		up->port.icount.dsr++;
> +	if (status & UART_MSR_DDCD)
> +		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
> +	if (status & UART_MSR_DCTS)
> +		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
> +
> +	wake_up_interruptible(&up->port.info->delta_msr_wait);
> +}
> +
> +/*
> + * This handles the interrupt from one port.
> + */
> +static inline irqreturn_t serial_omap_irq(int irq, void *dev_id)
> +{
> +	struct uart_omap_port *up = dev_id;
> +	unsigned int iir, lsr;
> +
> +	iir = serial_in(up, UART_IIR);
> +	if (iir & UART_IIR_NO_INT)
> +		return IRQ_NONE;
> +	lsr = serial_in(up, UART_LSR);
> +	if (lsr & UART_LSR_DR)
> +		receive_chars(up, &lsr);
> +	check_modem_status(up);
> +	if (lsr & UART_LSR_THRE)
> +		transmit_chars(up);
> +	return IRQ_HANDLED;
> +}
> +
> +static unsigned int serial_omap_tx_empty(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	unsigned long flags;
> +	unsigned int ret;
> +
> +	spin_lock_irqsave(&up->port.lock, flags);
> +	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
> +	spin_unlock_irqrestore(&up->port.lock, flags);
> +
> +	return ret;
> +}
> +
> +static unsigned int serial_omap_get_mctrl(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	unsigned char status;
> +	unsigned int ret;
> +
> +	status = serial_in(up, UART_MSR);
> +
> +	ret = 0;
> +	if (status & UART_MSR_DCD)
> +		ret |= TIOCM_CAR;
> +	if (status & UART_MSR_RI)
> +		ret |= TIOCM_RNG;
> +	if (status & UART_MSR_DSR)
> +		ret |= TIOCM_DSR;
> +	if (status & UART_MSR_CTS)
> +		ret |= TIOCM_CTS;
> +	return ret;
> +}
> +
> +static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	unsigned char mcr = 0;
> +
> +	if (mctrl & TIOCM_RTS)
> +		mcr |= UART_MCR_RTS;
> +	if (mctrl & TIOCM_DTR)
> +		mcr |= UART_MCR_DTR;
> +	if (mctrl & TIOCM_OUT1)
> +		mcr |= UART_MCR_OUT1;
> +	if (mctrl & TIOCM_OUT2)
> +		mcr |= UART_MCR_OUT2;
> +	if (mctrl & TIOCM_LOOP)
> +		mcr |= UART_MCR_LOOP;
> +
> +	mcr |= up->mcr;
> +
> +	serial_out(up, UART_MCR, mcr);
> +}
> +
> +static void serial_omap_break_ctl(struct uart_port *port, int break_state)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&up->port.lock, flags);
> +	if (break_state == -1)
> +		up->lcr |= UART_LCR_SBC;
> +	else
> +		up->lcr &= ~UART_LCR_SBC;
> +	serial_out(up, UART_LCR, up->lcr);
> +	spin_unlock_irqrestore(&up->port.lock, flags);
> +}
> +
> +static int serial_omap_startup(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	unsigned long flags;
> +	int retval;
> +
> +	enable_uart_clocks(up);
> +
> +	/*
> +	 * Allocate the IRQ
> +	 */
> +	retval = request_irq(up->port.irq, serial_omap_irq, 0, up->name, up);
> +	if (retval) {
> +		disable_uart_clocks(up);
> +		return retval;
> +	}
> +
> +	/* Stop the baud clock */
> +	serial_out(up, UART_LCR, 1 << 7);
> +	serial_out(up, UART_DLL, 0);
> +	serial_out(up, UART_DLM, 0);
> +	serial_out(up, UART_LCR, 0);
> +
> +	/* Reset the UART */
> +	serial_out(up, UART_OMAP_MDR1, 0x07);
> +	serial_out(up, UART_OMAP_SCR, 0x08);
> +	serial_out(up, UART_OMAP_MDR1, 0x00);
> +	serial_out(up, UART_OMAP_SYSC, (0x02 << 3) | (1 << 2) | (1 << 0));
> +
> +
> +	/* Enable access to EFR */
> +	serial_out(up, UART_LCR, 0xbf);
> +	/* Enable access to extra features */
> +	serial_out(up, UART_EFR, 1 << 4);
> +	/* Enable sleep mode */
> +	serial_out(up, UART_IER, 1 << 4);
> +
> +	/* Set FIFO triggering */
> +	serial_out(up, UART_SCR, 0x00);
> +	serial_out(up, UART_FCR, (0x01 << 6) | (0x01 << 4) |
> +		   UART_FCR_ENABLE_FIFO);
> +	serial_out(up, UART_FCR, (0x01 << 6) | (0x01 << 4) |
> +		   UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT |
> +		   UART_FCR_ENABLE_FIFO);
> +	udelay(50);
> +
> +	/* Disable access to extra features */
> +	serial_out(up, UART_EFR, 0);
> +
> +	serial_out(up, UART_FCR, 0);
> +	serial_out(up, UART_LCR, 0x00);
> +
> +	/*
> +	 * Clear the interrupt registers.
> +	 */
> +	(void) serial_in(up, UART_LSR);
> +	(void) serial_in(up, UART_RX);
> +	(void) serial_in(up, UART_IIR);
> +	(void) serial_in(up, UART_MSR);
> +
> +	/*
> +	 * Now, initialize the UART
> +	 */
> +	serial_out(up, UART_LCR, UART_LCR_WLEN8);
> +
> +	spin_lock_irqsave(&up->port.lock, flags);
> +	up->port.mctrl |= TIOCM_OUT2;
> +	serial_omap_set_mctrl(&up->port, up->port.mctrl);
> +	spin_unlock_irqrestore(&up->port.lock, flags);
> +
> +	/*
> +	 * Finally, enable interrupts.  Note: Modem status interrupts
> +	 * are set via set_termios(), which will be occurring imminently
> +	 * anyway, so we don't enable them here.
> +	 */
> +	up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE;
> +	serial_out(up, UART_IER, up->ier);
> +
> +	/*
> +	 * And clear the interrupt registers again for luck.
> +	 */
> +	(void) serial_in(up, UART_LSR);
> +	(void) serial_in(up, UART_RX);
> +	(void) serial_in(up, UART_IIR);
> +	(void) serial_in(up, UART_MSR);
> +
> +	return 0;
> +}
> +
> +static void serial_omap_shutdown(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	unsigned long flags;
> +
> +	free_irq(up->port.irq, up);
> +
> +	/*
> +	 * Disable interrupts from this port
> +	 */
> +	up->ier = 0;
> +	serial_out(up, UART_IER, 0);
> +
> +	spin_lock_irqsave(&up->port.lock, flags);
> +	up->port.mctrl &= ~TIOCM_OUT2;
> +	serial_omap_set_mctrl(&up->port, up->port.mctrl);
> +	spin_unlock_irqrestore(&up->port.lock, flags);
> +
> +	/*
> +	 * Disable break condition and FIFOs
> +	 */
> +	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
> +	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
> +				  UART_FCR_CLEAR_RCVR |
> +				  UART_FCR_CLEAR_XMIT);
> +	serial_out(up, UART_FCR, 0);
> +
> +	disable_uart_clocks(up);
> +
> +	clk_put(up->fclk);
> +	if (up->iclk != NULL)
> +		clk_put(up->iclk);
> +}
> +
> +static void
> +serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
> +			struct ktermios *old)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	unsigned char cval, fcr = 0;
> +	unsigned long flags;
> +	unsigned int baud, quot;
> +
> +	switch (termios->c_cflag & CSIZE) {
> +	case CS5:
> +		cval = UART_LCR_WLEN5;
> +		break;
> +	case CS6:
> +		cval = UART_LCR_WLEN6;
> +		break;
> +	case CS7:
> +		cval = UART_LCR_WLEN7;
> +		break;
> +	default:
> +	case CS8:
> +		cval = UART_LCR_WLEN8;
> +		break;
> +	}
> +
> +	if (termios->c_cflag & CSTOPB)
> +		cval |= UART_LCR_STOP;
> +	if (termios->c_cflag & PARENB)
> +		cval |= UART_LCR_PARITY;
> +	if (!(termios->c_cflag & PARODD))
> +		cval |= UART_LCR_EPAR;
> +
> +	/*
> +	 * 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);
> +
> +	fcr = (0x01 << 6) | (0x01 << 4) | UART_FCR_ENABLE_FIFO;
> +
> +	/*
> +	 * Ok, we're now changing the port state.  Do it with
> +	 * interrupts disabled.
> +	 */
> +	spin_lock_irqsave(&up->port.lock, flags);
> +
> +	/*
> +	 * Update the per-port timeout.
> +	 */
> +	uart_update_timeout(port, termios->c_cflag, baud);
> +
> +	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
> +	if (termios->c_iflag & INPCK)
> +		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
> +	if (termios->c_iflag & (BRKINT | PARMRK))
> +		up->port.read_status_mask |= UART_LSR_BI;
> +
> +	/*
> +	 * Characters to ignore
> +	 */
> +	up->port.ignore_status_mask = 0;
> +	if (termios->c_iflag & IGNPAR)
> +		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
> +	if (termios->c_iflag & IGNBRK) {
> +		up->port.ignore_status_mask |= UART_LSR_BI;
> +		/*
> +		 * If we're ignoring parity and break indicators,
> +		 * ignore overruns too (for real raw support).
> +		 */
> +		if (termios->c_iflag & IGNPAR)
> +			up->port.ignore_status_mask |= UART_LSR_OE;
> +	}
> +
> +	/*
> +	 * ignore all characters if CREAD is not set
> +	 */
> +	if ((termios->c_cflag & CREAD) == 0)
> +		up->port.ignore_status_mask |= UART_LSR_DR;
> +
> +	/*
> +	 * CTS flow control flag and modem status interrupts
> +	 */
> +	up->ier &= ~UART_IER_MSI;
> +	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
> +		up->ier |= UART_IER_MSI;
> +
> +	serial_out(up, UART_IER, up->ier);
> +
> +	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
> +	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
> +	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
> +	serial_out(up, UART_LCR, cval);		/* reset DLAB */
> +	up->lcr = cval;					/* Save LCR */
> +	serial_omap_set_mctrl(&up->port, up->port.mctrl);
> +	serial_out(up, UART_FCR, fcr);
> +	spin_unlock_irqrestore(&up->port.lock, flags);
> +}
> +
> +static void
> +serial_omap_pm(struct uart_port *port, unsigned int state,
> +	       unsigned int oldstate)
> +{
> +	/* TODO: can move enable/disable_uart_clock here and
> +	 * other pm related changes
> +	 */
> +}
> +
> +static void serial_omap_release_port(struct uart_port *port)
> +{
> +}
> +
> +static int serial_omap_request_port(struct uart_port *port)
> +{
> +	return 0;
> +}
> +
> +static void serial_omap_config_port(struct uart_port *port, int flags)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	up->port.type = PORT_OMAP;
> +}
> +
> +static int
> +serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser)
> +{
> +	/* we don't want the core code to modify any port params */
> +	return -EINVAL;
> +}
> +
> +static const char *
> +serial_omap_type(struct uart_port *port)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +	return up->name;
> +}
> +
> +#ifdef CONFIG_SERIAL_OMAP_CONSOLE
> +
> +static struct uart_omap_port *serial_omap_console_ports[3];
> +
> +static struct uart_driver serial_omap_reg;
> +
> +#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
> +
> +/*
> + *	Wait for transmitter & holding register to empty
> + */
> +static inline void wait_for_xmitr(struct uart_omap_port *up)
> +{
> +	unsigned int status, tmout = 10000;
> +
> +	/* Wait up to 10ms for the character(s) to be sent. */
> +	do {
> +		status = serial_in(up, UART_LSR);
> +
> +		if (status & UART_LSR_BI)
> +			up->lsr_break_flag = UART_LSR_BI;
> +
> +		if (--tmout == 0)
> +			break;
> +		udelay(1);
> +	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
> +
> +	/* Wait up to 1s for flow control if necessary */
> +	if (up->port.flags & UPF_CONS_FLOW) {
> +		tmout = 1000000;
> +		while (--tmout &&
> +		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
> +			udelay(1);
> +	}
> +}
> +
> +static void serial_omap_console_putchar(struct uart_port *port, int ch)
> +{
> +	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +
> +	wait_for_xmitr(up);
> +	serial_out(up, UART_TX, ch);
> +}
> +
> +/*
> + * Print a string to the serial port trying not to disturb
> + * any possible real use of the port...
> + *
> + *	The console_lock must be held when we get here.
> + */
> +static void
> +serial_omap_console_write(struct console *co, const char *s, unsigned int
> +count)
> +{
> +	struct uart_omap_port *up = serial_omap_console_ports[co->index];
> +	unsigned int ier;
> +
> +	/*
> +	 *	First save the IER then disable the interrupts
> +	 */
> +	ier = serial_in(up, UART_IER);
> +	serial_out(up, UART_IER, 0);
> +
> +	uart_console_write(&up->port, s, count, serial_omap_console_putchar);
> +
> +	/*
> +	 *	Finally, wait for transmitter to become empty
> +	 *	and restore the IER
> +	 */
> +	wait_for_xmitr(up);
> +	serial_out(up, UART_IER, ier);
> +}
> +
> +static int __init
> +serial_omap_console_setup(struct console *co, char *options)
> +{
> +	struct uart_omap_port *up;
> +	int baud = 9600;
> +	int bits = 8;
> +	int parity = 'n';
> +	int flow = 'n';
> +	int r;
> +
> +	if (serial_omap_console_ports[co->index] == NULL)
> +		return -ENODEV;
> +	up = serial_omap_console_ports[co->index];
> +
> +	enable_uart_clocks(up);
> +
> +	if (options)
> +		uart_parse_options(options, &baud, &parity, &bits, &flow);
> +
> +	r = uart_set_options(&up->port, co, baud, parity, bits, flow);
> +
> +	return r;
> +}
> +
> +static struct console serial_omap_console = {
> +	.name		= "ttyS",
> +	.write		= serial_omap_console_write,
> +	.device		= uart_console_device,
> +	.setup		= serial_omap_console_setup,
> +	.flags		= CON_PRINTBUFFER,
> +	.index		= -1,
> +	.data		= &serial_omap_reg,
> +};
> +

AFAIK using ttyS name will break hot-plug 8250 ports, such as CF ports.
How about using ttyO or something similar? I guess the minor number also
needs to be different then.

In general, will this driver also work on DaVinci? Maybe use name like
serial_ti or similar?


> +static void serial_omap_add_console_port(struct uart_omap_port *up)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(serial_omap_console_ports); i++)
> +		if (serial_omap_console_ports[i] == NULL) {
> +			serial_omap_console_ports[i] = up;
> +			break;
> +		}
> +}
> +
> +#define OMAP_CONSOLE	(&serial_omap_console)
> +
> +#else
> +
> +#define OMAP_CONSOLE	NULL
> +
> +static inline void serial_omap_add_console_port(struct uart_omap_port *up) {}
> +
> +#endif
> +
> +struct uart_ops serial_omap_pops = {
> +	.tx_empty	= serial_omap_tx_empty,
> +	.set_mctrl	= serial_omap_set_mctrl,
> +	.get_mctrl	= serial_omap_get_mctrl,
> +	.stop_tx	= serial_omap_stop_tx,
> +	.start_tx	= serial_omap_start_tx,
> +	.stop_rx	= serial_omap_stop_rx,
> +	.enable_ms	= serial_omap_enable_ms,
> +	.break_ctl	= serial_omap_break_ctl,
> +	.startup	= serial_omap_startup,
> +	.shutdown	= serial_omap_shutdown,
> +	.set_termios	= serial_omap_set_termios,
> +	.pm		= serial_omap_pm,
> +	.type		= serial_omap_type,
> +	.release_port	= serial_omap_release_port,
> +	.request_port	= serial_omap_request_port,
> +	.config_port	= serial_omap_config_port,
> +	.verify_port	= serial_omap_verify_port,
> +};
> +
> +static struct uart_driver serial_omap_reg = {
> +	.owner		= THIS_MODULE,
> +	.driver_name	= "OMAP-SERIAL",
> +	.dev_name	= "ttyS",
> +	.major		= TTY_MAJOR,
> +	.minor		= 64,
> +	.nr		= 3,
> +	.cons		= OMAP_CONSOLE,
> +};
> +
> +static int serial_omap_suspend(struct platform_device *dev, pm_message_t state)
> +{
> +	struct uart_omap_port *sport = platform_get_drvdata(dev);
> +
> +	if (sport)
> +		uart_suspend_port(&serial_omap_reg, &sport->port);
> +
> +	return 0;
> +}
> +
> +static int serial_omap_resume(struct platform_device *dev)
> +{
> +	struct uart_omap_port *sport = platform_get_drvdata(dev);
> +
> +	if (sport)
> +		uart_resume_port(&serial_omap_reg, &sport->port);
> +
> +	return 0;
> +}
> +
> +static int line;
> +
> +static int serial_omap_probe(struct platform_device *pdev)
> +{
> +	struct uart_omap_port	*up;
> +	struct resource		*mem, *irq;
> +	char			buf[16];
> +	int r;
> +
> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!mem) {
> +		dev_err(&pdev->dev, "no mem resource?\n");
> +		return -ENODEV;
> +	}
> +	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> +	if (!irq) {
> +		dev_err(&pdev->dev, "no irq resource?\n");
> +		return -ENODEV;
> +	}
> +
> +	r = (int) request_mem_region(mem->start, (mem->end - mem->start) + 1,
> +				     pdev->dev.driver->name);
> +	if (!r) {
> +		dev_err(&pdev->dev, "memory region already claimed\n");
> +		return -EBUSY;
> +	}
> +
> +	up = kzalloc(sizeof(*up), GFP_KERNEL);
> +	if (up == NULL) {
> +		r = -ENOMEM;
> +		goto do_release_region;
> +	}
> +	sprintf(up->name, "OMAP UART%d", pdev->id);
> +
> +	platform_set_drvdata(pdev, up);
> +	up->pdev = pdev;
> +
> +	if (!cpu_class_is_omap1()) {
> +		sprintf(buf, "uart%d_fck", pdev->id);
> +		up->fclk = clk_get(&pdev->dev, buf);
> +		if (IS_ERR(up->fclk)) {
> +			dev_err(&pdev->dev, "could not get fclk\n");
> +			return PTR_ERR(up->fclk);
> +		}
> +		sprintf(buf, "uart%d_ick", pdev->id);
> +		up->iclk = clk_get(&pdev->dev, buf);
> +		if (IS_ERR(up->iclk)) {
> +			dev_err(&pdev->dev, "could not get iclk\n");
> +			clk_put(up->fclk);
> +			return PTR_ERR(up->iclk);
> +		}
> +	}
> +
> +	up->port.type = PORT_OMAP;
> +	up->port.iotype = UPIO_MEM;
> +	up->port.membase = (void *) io_p2v(mem->start);
> +	up->port.mapbase = mem->start;
> +	up->port.irq = irq->start;
> +	up->port.fifosize = 64;
> +	up->port.ops = &serial_omap_pops;
> +	up->port.line = line++;
> +
> +	up->port.uartclk = 2995200 * 16;
> +	up->shift = 2;
> +
> +	serial_omap_add_console_port(up);
> +
> +	uart_add_one_port(&serial_omap_reg, &up->port);
> +	platform_set_drvdata(pdev, up);
> +
> +	return 0;
> +
> +do_release_region:
> +	release_mem_region(mem->start, (mem->end - mem->start) + 1);
> +	return r;
> +}
> +
> +static int serial_omap_remove(struct platform_device *dev)
> +{
> +	struct uart_omap_port *sport = platform_get_drvdata(dev);
> +
> +	platform_set_drvdata(dev, NULL);
> +
> +	if (sport)
> +		uart_remove_one_port(&serial_omap_reg, &sport->port);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver serial_omap_driver = {
> +	.probe          = serial_omap_probe,
> +	.remove         = serial_omap_remove,
> +
> +	.suspend	= serial_omap_suspend,
> +	.resume		= serial_omap_resume,
> +	.driver		= {
> +		.name	= "omap-uart",
> +	},
> +};
> +
> +int __init serial_omap_init(void)
> +{
> +	int ret;
> +
> +	ret = uart_register_driver(&serial_omap_reg);
> +	if (ret != 0)
> +		return ret;
> +
> +	ret = platform_driver_register(&serial_omap_driver);
> +	if (ret != 0)
> +		uart_unregister_driver(&serial_omap_reg);
> +
> +	return ret;
> +}
> +
> +void __exit serial_omap_exit(void)
> +{
> +	platform_driver_unregister(&serial_omap_driver);
> +	uart_unregister_driver(&serial_omap_reg);
> +}
> +
> +subsys_initcall(serial_omap_init);
> +module_exit(serial_omap_exit);
> +
> +MODULE_LICENSE("GPL");
> Index: linux-omap-2.6/include/linux/serial_core.h
> ===================================================================
> --- linux-omap-2.6.orig/include/linux/serial_core.h	2008-07-31
> 11:15:55.000000000 +0530
> +++ linux-omap-2.6/include/linux/serial_core.h	2008-07-31 11:25:24.000000000 +0530
> @@ -158,6 +158,9 @@
> 
>  #define PORT_SC26XX	82
> 
> +/* OMAP serial */
> +#define PORT_OMAP	83
> +
>  #ifdef __KERNEL__
> 
>  #include <linux/compiler.h>
> 
> --
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