[U-Boot-Users] [PATCH 5/7] serial: add s3c64xx serial driver

[Jean-Christophe PLAGNIOL-VILLARD]

On 12:54 Thu 31 Jul     , Guennadi Liakhovetski wrote:
> Ported from u-boot-1.1.6 driver by Samsung.
> 
> Signed-off-by: Guennadi Liakhovetski <lg at denx.de>
> ---
>  drivers/serial/Makefile  |    1 +
>  drivers/serial/s3c64xx.c |  189 ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 190 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/serial/s3c64xx.c
> 
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index c9e797e..70fe638 100644
> --- a/drivers/serial/Makefile
> +++ b/drivers/serial/Makefile
> @@ -36,6 +36,7 @@ COBJS-y += serial_pl010.o
>  COBJS-y += serial_pl011.o
>  COBJS-y += serial_xuartlite.o
>  COBJS-y += serial_sh.o
> +COBJS-$(CONFIG_S3C64XX) += s3c64xx.o
>  COBJS-y += usbtty.o
>  
>  COBJS	:= $(COBJS-y)
> diff --git a/drivers/serial/s3c64xx.c b/drivers/serial/s3c64xx.c
> new file mode 100644
> index 0000000..d7e9d01
> --- /dev/null
> +++ b/drivers/serial/s3c64xx.c
> @@ -0,0 +1,189 @@
> +/*
> + * (C) Copyright 2002
> + * Gary Jennejohn, DENX Software Engineering, <gj at denx.de>
> + *
> + * 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
> + *
> + */
> +
> +#include <common.h>
> +
> +#include <s3c6400.h>
> +
> +#ifdef CONFIG_SERIAL1
> +#define UART_NR	S3C64XX_UART0
> +
> +#elif defined(CONFIG_SERIAL2)
> +#define UART_NR	S3C64XX_UART1
> +
> +#elif defined(CONFIG_SERIAL3)
> +#define UART_NR	S3C64XX_UART2
> +
> +#else
> +#error "Bad: you didn't configure serial ..."
> +#endif
> +
> +#define barrier() asm volatile("" ::: "memory")
> +
> +/* See table in 31.6.11 */
> +static const int udivslot[] = {
> +	0,
> +	0x0080,
> +	0x0808,
> +	0x0888,
> +	0x2222,
> +	0x4924,
> +	0x4a52,
> +	0x54aa,
> +	0x5555,
> +	0xd555,
> +	0xd5d5,
> +	0xddd5,
> +	0xdddd,
> +	0xdfdd,
> +	0xdfdf,
> +	0xffdf,
> +};
> +
> +void serial_setbrg(void)
> +{
> +	DECLARE_GLOBAL_DATA_PTR;
> +	S3C64XX_UART *const uart = S3C64XX_GetBase_UART(UART_NR);
> +	u32 reg, pclk_ratio = get_PCLK() / gd->baudrate;
> +	int i;
> +
> +	/* PCLK / (16 * baudrate) - 1 */
> +	reg = pclk_ratio / 16 - 1;
> +	i = pclk_ratio - (reg + 1) * 16;
> +
> +	uart->UBRDIV = reg;
> +	uart->UDIVSLOT = udivslot[i];
> +
> +	for (i = 0; i < 100; i++)
> +		barrier();
> +}
> +
> +/*
> + * Initialise the serial port with the given baudrate. The settings
> + * are always 8 data bits, no parity, 1 stop bit, no start bits.
> + *
> + */
> +int serial_init(void)
> +{
> +	S3C64XX_UART *const uart = S3C64XX_GetBase_UART(UART_NR);
please do not use UPPERCASE var name and function & co
> +
> +	/* reset and enable FIFOs, set triggers to the maximum */
> +	uart->UFCON = 0xff;
> +	uart->UMCON = 0;
> +	/* 8N1 */
> +	uart->ULCON = 3;
> +	/* No interrupts, no DMA, pure polling */
> +	uart->UCON = 5;
> +
> +	serial_setbrg();
> +
> +	return 0;
> +}
> +
> +/*
> + * Read a single byte from the serial port. Returns 1 on success, 0
> + * otherwise. When the function is succesfull, the character read is
> + * written into its argument c.
> + */
> +int serial_getc(void)
> +{
> +	S3C64XX_UART *const uart = S3C64XX_GetBase_UART(UART_NR);
> +
> +	/* wait for character to arrive */
> +	while (!(uart->UTRSTAT & 0x1));
> +
> +	return uart->URXH & 0xff;
> +}
> +
> +#ifdef CONFIG_HWFLOW
> +static int hwflow = 0;		/* turned off by default */
> +int hwflow_onoff(int on)
> +{
> +	switch (on) {
> +	case 0:
> +	default:
> +		break;		/* return current */
IMHO it's weird to have the default at top
> +	case 1:
> +		hwflow = 1;	/* turn on */
> +		break;
> +	case -1:
> +		hwflow = 0;	/* turn off */
> +		break;
> +	}
> +	return hwflow;
> +}
> +#endif
> +

Best Regards,
J.