Re: [PATCH v2 10/10] ARM: S5PV210: Add serial port support

[Ben Dooks <ben-linux@fluff.org>]

On Thu, Jan 21, 2010 at 08:57:58AM +0900, Kukjin Kim wrote:
> This patch adds UART serial port support for S5PV210.
> 
> Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
> ---
>  arch/arm/plat-s3c/include/plat/regs-serial.h |   30 +++++
>  drivers/serial/Kconfig                       |    9 ++-
>  drivers/serial/Makefile                      |    1 +
>  drivers/serial/s5pv210.c                     |  149 ++++++++++++++++++++++++++
>  4 files changed, 188 insertions(+), 1 deletions(-)
>  create mode 100644 drivers/serial/s5pv210.c
> 
> diff --git a/arch/arm/plat-s3c/include/plat/regs-serial.h b/arch/arm/plat-s3c/include/plat/regs-serial.h
> index 85d8904..60d6604 100644
> --- a/arch/arm/plat-s3c/include/plat/regs-serial.h
> +++ b/arch/arm/plat-s3c/include/plat/regs-serial.h
> @@ -194,6 +194,36 @@
>  #define S3C64XX_UINTSP		0x34
>  #define S3C64XX_UINTM		0x38
>  
> +/* Following are specific to S5PV210 and S5P6442 */
> +#define S5PV210_UCON_CLKMASK	(1<<10)
> +#define S5PV210_UCON_PCLK	(0<<10)
> +#define S5PV210_UCON_UCLK	(1<<10)
> +
> +#define S5PV210_UFCON_TXTRIG0	(0<<8)
> +#define S5PV210_UFCON_TXTRIG4	(1<<8)
> +#define S5PV210_UFCON_TXTRIG8	(2<<8)
> +#define S5PV210_UFCON_TXTRIG16	(3<<8)
> +#define S5PV210_UFCON_TXTRIG32	(4<<8)
> +#define S5PV210_UFCON_TXTRIG64	(5<<8)
> +#define S5PV210_UFCON_TXTRIG128 (6<<8)
> +#define S5PV210_UFCON_TXTRIG256 (7<<8)
> +
> +#define S5PV210_UFCON_RXTRIG1	(0<<4)
> +#define S5PV210_UFCON_RXTRIG4	(1<<4)
> +#define S5PV210_UFCON_RXTRIG8	(2<<4)
> +#define S5PV210_UFCON_RXTRIG16	(3<<4)
> +#define S5PV210_UFCON_RXTRIG32	(4<<4)
> +#define S5PV210_UFCON_RXTRIG64	(5<<4)
> +#define S5PV210_UFCON_RXTRIG128	(6<<4)
> +#define S5PV210_UFCON_RXTRIG256	(7<<4)
> +
> +#define S5PV210_UFSTAT_TXFULL	(1<<24)
> +#define S5PV210_UFSTAT_RXFULL	(1<<8)
> +#define S5PV210_UFSTAT_TXMASK	(255<<16)
> +#define S5PV210_UFSTAT_TXSHIFT	(16)
> +#define S5PV210_UFSTAT_RXMASK	(255<<0)
> +#define S5PV210_UFSTAT_RXSHIFT	(0)
> +
>  #ifndef __ASSEMBLY__
>  
>  /* struct s3c24xx_uart_clksrc
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
> index d7d687f..ebdd2b9 100644
> --- a/drivers/serial/Kconfig
> +++ b/drivers/serial/Kconfig
> @@ -459,7 +459,7 @@ config SERIAL_SAMSUNG_UARTS
>  	int
>  	depends on ARM && PLAT_S3C
>  	default 2 if ARCH_S3C2400
> -	default 4 if ARCH_S5P6440 || ARCH_S5PC1XX || ARCH_S3C64XX || CPU_S3C2443
> +	default 4 if ARCH_S5P6440 || ARCH_S5PC1XX || ARCH_S5PV210 || ARCH_S3C64XX || CPU_S3C2443
>  	default 3

I think we can tidy this up with an intermediate configuration for the
case wherer we have 4 UARTS, although this doesn't need to be done now,
example being:

config SERIAL_SAMSUNG_4UARTS
        bool
        depends on ARM && PLAT_S3C
	help
	  Internal node to say we have 4 YARTS

config SERIAL_SAMSUNG_UARTS
       depends on ARM && PLAT_S3C
       default 2 if ARCH_S3C2400
       default 4 if SERIAL_SAMSUNG_4UARTS
       default 3
       ...

and then select SERIAL_SAMSUNG_4UARTS as necessary.

>  	help
>  	  Select the number of available UART ports for the Samsung S3C
> @@ -540,6 +540,13 @@ config SERIAL_S5PC100
>  	help
>  	  Serial port support for the Samsung S5PC100 SoCs
>  
> +config SERIAL_S5PV210
> +	tristate "Samsung S5PV210 Serial port support"
> +	depends on SERIAL_SAMSUNG && CPU_S5PV210
> +	default y
> +	help
> +	  Serial port support for Samsung's S5P Family of SoC's
> +
>  config SERIAL_MAX3100
>  	tristate "MAX3100 support"
>  	depends on SPI
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index 5548fe7..6aa4723 100644
> --- a/drivers/serial/Makefile
> +++ b/drivers/serial/Makefile
> @@ -45,6 +45,7 @@ obj-$(CONFIG_SERIAL_S3C2440) += s3c2440.o
>  obj-$(CONFIG_SERIAL_S3C24A0) += s3c24a0.o
>  obj-$(CONFIG_SERIAL_S3C6400) += s3c6400.o
>  obj-$(CONFIG_SERIAL_S5PC100) += s3c6400.o
> +obj-$(CONFIG_SERIAL_S5PV210) += s5pv210.o
>  obj-$(CONFIG_SERIAL_MAX3100) += max3100.o
>  obj-$(CONFIG_SERIAL_IP22_ZILOG) += ip22zilog.o
>  obj-$(CONFIG_SERIAL_MUX) += mux.o
> diff --git a/drivers/serial/s5pv210.c b/drivers/serial/s5pv210.c
> new file mode 100644
> index 0000000..0064a77
> --- /dev/null
> +++ b/drivers/serial/s5pv210.c
> @@ -0,0 +1,149 @@
> +/* linux/drivers/serial/s5pv210.c
> + *
> + * Copyright (c) 2010 Samsung Electronics Co., Ltd.
> + *		http://www.samsung.com/
> + *
> + * Based on drivers/serial/s3c6400.c
> + *
> + * Driver for Samsung S5PV210 SoC UARTs.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> +*/
> +
> +#include <linux/module.h>
> +#include <linux/ioport.h>
> +#include <linux/io.h>
> +#include <linux/platform_device.h>
> +#include <linux/init.h>
> +#include <linux/serial_core.h>
> +#include <linux/serial.h>
> +
> +#include <asm/irq.h>
> +#include <mach/hardware.h>
> +#include <plat/regs-serial.h>
> +#include "samsung.h"
> +
> +static int s5pv210_serial_setsource(struct uart_port *port,
> +					struct s3c24xx_uart_clksrc *clk)
> +{
> +	unsigned long ucon = rd_regl(port, S3C2410_UCON);
> +
> +	if (strcmp(clk->name, "pclk") == 0)
> +		ucon &= ~S5PV210_UCON_CLKMASK;
> +	else if (strcmp(clk->name, "uclk1") == 0)
> +		ucon |= S5PV210_UCON_CLKMASK;
> +	else {
> +		printk(KERN_ERR "unknown clock source %s\n", clk->name);
> +		return -EINVAL;
> +	}
> +
> +	wr_regl(port, S3C2410_UCON, ucon);
> +	return 0;
> +}
> +
> +
> +static int s5pv210_serial_getsource(struct uart_port *port,
> +					struct s3c24xx_uart_clksrc *clk)
> +{
> +	u32 ucon = rd_regl(port, S3C2410_UCON);
> +
> +	clk->divisor = 1;
> +
> +	switch (ucon & S5PV210_UCON_CLKMASK) {
> +	case S5PV210_UCON_PCLK:
> +		clk->name = "pclk";
> +		break;
> +	case S5PV210_UCON_UCLK:
> +		clk->name = "uclk1";
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int s5pv210_serial_resetport(struct uart_port *port,
> +					struct s3c2410_uartcfg *cfg)
> +{
> +	unsigned long ucon = rd_regl(port, S3C2410_UCON);
> +
> +	ucon &= S5PV210_UCON_CLKMASK;
> +	wr_regl(port, S3C2410_UCON,  ucon | cfg->ucon);
> +	wr_regl(port, S3C2410_ULCON, cfg->ulcon);
> +
> +	/* reset both fifos */
> +	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
> +	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
> +
> +	return 0;
> +}
> +
> +#define S5PV210_UART_DEFAULT_INFO(FIFO_SIZE) 	{		\
> +		.name		= "Samsung S5PV210 UART0",	\
> +		.type		= PORT_S3C6400,			\
> +		.fifosize	= FIFO_SIZE,			\
> +		.has_divslot	= 1,				\
> +		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
> +		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
> +		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
> +		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
> +		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
> +		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
> +		.get_clksrc	= s5pv210_serial_getsource,	\
> +		.set_clksrc	= s5pv210_serial_setsource,	\
> +		.reset_port	= s5pv210_serial_resetport,	\
> +	}
> +
> +static struct s3c24xx_uart_info s5p_uart_inf[] = {
> +	[0] = S5PV210_UART_DEFAULT_INFO(256),
> +	[1] = S5PV210_UART_DEFAULT_INFO(64),
> +	[2] = S5PV210_UART_DEFAULT_INFO(16),
> +	[3] = S5PV210_UART_DEFAULT_INFO(16),
> +};
> +
> +/* device management */
> +static int s5p_serial_probe(struct platform_device *pdev)
> +{
> +	return s3c24xx_serial_probe(pdev, &s5p_uart_inf[pdev->id]);
> +}

I'll check if this is correct, can't remember if pdev->id is a 1:1 mapping
to the uart port or not.

> +static struct platform_driver s5p_serial_drv = {
> +	.probe		= s5p_serial_probe,
> +	.remove		= s3c24xx_serial_remove,
> +	.driver		= {
> +		.name	= "s5pv210-uart",
> +		.owner	= THIS_MODULE,
> +	},
> +};
> +
> +static int __init s5pv210_serial_console_init(void)
> +{
> +	struct s3c24xx_uart_info *uinfo[CONFIG_SERIAL_SAMSUNG_UARTS];
> +	int i;
> +
> +	for (i = 0; i < CONFIG_SERIAL_SAMSUNG_UARTS; i++)
> +		uinfo[i] = &s5p_uart_inf[i];

surely you don't need to copy here, just do
       return s3c24xx_serial_initconsole(&s5p_serial_drv, s5p_uart_inf);

> +	return s3c24xx_serial_initconsole(&s5p_serial_drv, uinfo);
> +}
> +
> +console_initcall(s5pv210_serial_console_init);
> +
> +static int __init s5p_serial_init(void)
> +{
> +	return s3c24xx_serial_init(&s5p_serial_drv, s5p_uart_inf);
> +}
> +
> +static void __exit s5p_serial_exit(void)
> +{
> +	platform_driver_unregister(&s5p_serial_drv);
> +}
> +
> +module_init(s5p_serial_init);
> +module_exit(s5p_serial_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:s5pv210-uart");
> +MODULE_DESCRIPTION("Samsung S5PV210 UART Driver support");
> +MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com>");
> -- 
> 1.6.2.5

-- 
Ben

Q:      What's a light-year?
A:      One-third less calories than a regular year.