[PATCH 1/7] Support most Samsung SoCs in S3C serial driver
Sascha Hauer
s.hauer at pengutronix.de
Mon May 14 13:46:48 EDT 2012
On Mon, May 14, 2012 at 03:38:05PM +0600, Alexey Galakhov wrote:
> Ok, I assume this should go into separate series. It fits both S5PV210 and S3C6410.
>
> This adds support for S3C and S5P architectures (all of my knowledge) to the
> serial driver. Since the only difference between them is in clock handling,
> this is moved to an arch-dependent separate function.
>
> Most modern architectures should define S3C_UART_HAS_UBRDIVSLOT and S3C_UART_HAS_UINTM.
>
> This adds support for most
>
> Signed-off-by: Alexey Galakhov <agalakhov at gmail.com>
Applied, thanks
Sascha
> ---
> arch/arm/mach-samsung/include/mach/s3c-generic.h | 4 ++
> arch/arm/mach-samsung/s3c24xx-clocks.c | 17 +++++++
> drivers/serial/Kconfig | 2 +-
> drivers/serial/serial_s3c.c | 55 +++++++++++++++-------
> 4 files changed, 60 insertions(+), 18 deletions(-)
>
> diff --git a/arch/arm/mach-samsung/include/mach/s3c-generic.h b/arch/arm/mach-samsung/include/mach/s3c-generic.h
> index 4ea3dd7..5d3808e 100644
> --- a/arch/arm/mach-samsung/include/mach/s3c-generic.h
> +++ b/arch/arm/mach-samsung/include/mach/s3c-generic.h
> @@ -30,5 +30,9 @@ uint32_t s3c_get_fclk(void);
> uint32_t s3c_get_hclk(void);
> uint32_t s3c_get_pclk(void);
> uint32_t s3c_get_uclk(void);
> +
> +unsigned s3c_get_uart_clk(unsigned src);
> +
> uint32_t s3c24xx_get_memory_size(void);
> +
> void s3c24xx_disable_second_sdram_bank(void);
> diff --git a/arch/arm/mach-samsung/s3c24xx-clocks.c b/arch/arm/mach-samsung/s3c24xx-clocks.c
> index a99d1b9..38d8b75 100644
> --- a/arch/arm/mach-samsung/s3c24xx-clocks.c
> +++ b/arch/arm/mach-samsung/s3c24xx-clocks.c
> @@ -117,6 +117,23 @@ uint32_t s3c24_get_uclk(void)
> return s3c_get_upllclk();
> }
>
> +/**
> + * Return correct UART frequency based on the UCON register
> + */
> +unsigned s3c_get_uart_clk(unsigned src)
> +{
> + switch (src & 3) {
> + case 0:
> + case 2:
> + return s3c_get_pclk();
> + case 1:
> + return 0; /* TODO UEXTCLK */
> + case 3:
> + return 0; /* TODO FCLK/n */
> + }
> + return 0; /* not reached, to make compiler happy */
> +}
> +
> /**
> * Show the user the current clock settings
> */
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
> index 186b596..a9383da 100644
> --- a/drivers/serial/Kconfig
> +++ b/drivers/serial/Kconfig
> @@ -80,7 +80,7 @@ config DRIVER_SERIAL_PL010
>
> config DRIVER_SERIAL_S3C
> bool "Samsung S3C serial driver"
> - depends on ARCH_S3C24xx
> + depends on ARCH_SAMSUNG
> default y
> help
> Say Y here if you want to use the CONS on a Samsung S3C CPU
> diff --git a/drivers/serial/serial_s3c.c b/drivers/serial/serial_s3c.c
> index 2bdc1df..7a9b355 100644
> --- a/drivers/serial/serial_s3c.c
> +++ b/drivers/serial/serial_s3c.c
> @@ -40,6 +40,17 @@
> #define UTXH 0x20 /* transmitt */
> #define URXH 0x24 /* receive */
> #define UBRDIV 0x28 /* baudrate generator */
> +#ifdef S3C_UART_HAS_UBRDIVSLOT
> +# define UBRDIVSLOT 0x2c /* baudrate slot generator */
> +#endif
> +#ifdef S3C_UART_HAS_UINTM
> +# define UINTM 0x38 /* interrupt mask register */
> +#endif
> +
> +#ifndef S3C_UART_CLKSEL
> +/* Use pclk */
> +# define S3C_UART_CLKSEL 0
> +#endif
>
> struct s3c_uart {
> void __iomem *regs;
> @@ -51,26 +62,32 @@ struct s3c_uart {
> static unsigned s3c_get_arch_uart_input_clock(void __iomem *base)
> {
> unsigned reg = readw(base + UCON);
> -
> - switch (reg & 0xc00) {
> - case 0x000:
> - case 0x800:
> - return s3c_get_pclk();
> - case 0x400:
> - break; /* TODO UEXTCLK */
> - case 0xc00:
> - break; /* TODO FCLK/n */
> - }
> -
> - return 0; /* not nice, but we can't emit an error message! */
> + reg = (reg >> 10) & 0x3;
> + return s3c_get_uart_clk(reg);
> }
>
> +#ifdef S3C_UART_HAS_UBRDIVSLOT
> +/*
> + * This table takes the fractional value of the baud divisor and gives
> + * the recommended setting for the UDIVSLOT register. Refer the datasheet
> + * for further details
> + */
> +static const uint16_t udivslot_table[] __maybe_unused = {
> + 0x0000, 0x0080, 0x0808, 0x0888, 0x2222, 0x4924, 0x4A52, 0x54AA,
> + 0x5555, 0xD555, 0xD5D5, 0xDDD5, 0xDDDD, 0xDFDD, 0xDFDF, 0xFFDF,
> +};
> +#endif
> +
> static int s3c_serial_setbaudrate(struct console_device *cdev, int baudrate)
> {
> struct s3c_uart *priv = to_s3c_uart(cdev);
> void __iomem *base = priv->regs;
> unsigned val;
>
> +#ifdef S3C_UART_HAS_UBRDIVSLOT
> + val = s3c_get_arch_uart_input_clock(base) / baudrate;
> + writew(udivslot_table[val & 15], base + UBRDIVSLOT);
> +#endif
> val = s3c_get_arch_uart_input_clock(base) / (16 * baudrate) - 1;
> writew(val, base + UBRDIV);
>
> @@ -88,11 +105,15 @@ static int s3c_serial_init_port(struct console_device *cdev)
>
> /* Normal,No parity,1 stop,8 bit */
> writeb(0x03, base + ULCON);
> - /*
> - * tx=level,rx=edge,disable timeout int.,enable rx error int.,
> - * normal,interrupt or polling
> - */
> - writew(0x0245, base + UCON);
> +
> + /* tx=level,rx=edge,disable timeout int.,enable rx error int.,
> + * normal, interrupt or polling, no pre-divider */
> + writew(0x0245 | ((S3C_UART_CLKSEL) << 10), base + UCON);
> +
> +#ifdef S3C_UART_HAS_UINTM
> + /* 'interrupt or polling mode' for both directions */
> + writeb(0xf, base + UINTM);
> +#endif
>
> #ifdef CONFIG_DRIVER_SERIAL_S3C_AUTOSYNC
> writeb(0x10, base + UMCON); /* enable auto flow control */
> --
> 1.7.10
>
>
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