[U-Boot] [PATCH 3/4 v3] s5pc1xx: support serial driver

[Tom <Tom.Rix@windriver.com>]

Minkyu Kang wrote:
> This patch includes the serial driver for s5pc1xx
> 
> Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

Add a better commit log.
Explain why a special serial driver is needed instead
of using the generic serial driver.

> ---
> Changes since v1:
> - use serial multi API
> - use writel/readl function
> - remove duplicate code
> 
> Changes since v2:
> - use sizeof() instead of the constant
> 
>  common/serial.c                 |   18 +++
>  drivers/serial/Makefile         |    1 +
>  drivers/serial/serial_s5pc1xx.c |  307 +++++++++++++++++++++++++++++++++++++++
>  include/serial.h                |    7 +
>  4 files changed, 333 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/serial/serial_s5pc1xx.c
> 
> diff --git a/common/serial.c b/common/serial.c
> index 41a24c2..e5ce9fd 100644
> --- a/common/serial.c
> +++ b/common/serial.c
> @@ -69,6 +69,18 @@ struct serial_device *__default_serial_console (void)
>  #else
>  #error "CONFIG_SERIAL? missing."
>  #endif
> +#elif defined(CONFIG_S5PC1XX)
> +#if defined(CONFIG_SERIAL0)
> +	return &s5pc1xx_serial0_device;
> +#elif defined(CONFIG_SERIAL1)
> +	return &s5pc1xx_serial1_device;
> +#elif defined(CONFIG_SERIAL2)
> +	return &s5pc1xx_serial2_device;
> +#elif defined(CONFIG_SERIAL3)
> +	return &s5pc1xx_serial3_device;

This can be condensed down to

return S5PC1XX_DEFAULT_SERIAL_DEVICE

S5PC1XX_DEFAULT_SERIAL_DEVICE to be defined the board file.



> +#else
> +#error "CONFIG_SERIAL? missing."
> +#endif
>  #elif defined(CONFIG_OMAP3_ZOOM2)
>  		return ZOOM2_DEFAULT_SERIAL_DEVICE;
>  #else
> @@ -139,6 +151,12 @@ void serial_initialize (void)
>  	serial_register(&s3c24xx_serial1_device);
>  	serial_register(&s3c24xx_serial2_device);
>  #endif
> +#if defined(CONFIG_S5PC1XX)
> +	serial_register(&s5pc1xx_serial0_device);
> +	serial_register(&s5pc1xx_serial1_device);
> +	serial_register(&s5pc1xx_serial2_device);
> +	serial_register(&s5pc1xx_serial3_device);
> +#endif
>  	serial_assign (default_serial_console ()->name);
>  }
>  
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index 64882a2..3c77a7c 100644
> --- a/drivers/serial/Makefile
> +++ b/drivers/serial/Makefile
> @@ -33,6 +33,7 @@ COBJS-$(CONFIG_NS9750_UART) += ns9750_serial.o
>  COBJS-$(CONFIG_SYS_NS16550) += ns16550.o
>  COBJS-$(CONFIG_DRIVER_S3C4510_UART) += s3c4510b_uart.o
>  COBJS-$(CONFIG_S3C64XX) += s3c64xx.o
> +COBJS-$(CONFIG_S5PC1XX) += serial_s5pc1xx.o
>  COBJS-$(CONFIG_SYS_NS16550_SERIAL) += serial.o
>  COBJS-$(CONFIG_CLPS7111_SERIAL) += serial_clps7111.o
>  COBJS-$(CONFIG_IMX_SERIAL) += serial_imx.o
> diff --git a/drivers/serial/serial_s5pc1xx.c b/drivers/serial/serial_s5pc1xx.c
> new file mode 100644
> index 0000000..48feb4e
> --- /dev/null
> +++ b/drivers/serial/serial_s5pc1xx.c
> @@ -0,0 +1,307 @@
> +/*
> + * (C) Copyright 2009 SAMSUNG Electronics
> + * Minkyu Kang <mk7.kang@samsung.com>
> + * Heungjun Kim <riverful.kim@samsung.com>
> + *
> + * based on drivers/serial/s3c64xx.c
> + *
> + * 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 <asm/io.h>
> +#include <asm/arch/uart.h>
> +#include <asm/arch/clk.h>
> +
> +#if defined(CONFIG_SERIAL_MULTI)
> +#include <serial.h>
> +
> +/* Multi serial device functions */
> +#define DECLARE_S5P_SERIAL_FUNCTIONS(port) \
> +    int  s5p_serial##port##_init(void) { \
> +	return serial_init_dev(port); } \
> +    void s5p_serial##port##_setbrg(void) { \
> +	serial_setbrg_dev(port); } \
> +    int  s5p_serial##port##_getc(void) { \
> +	return serial_getc_dev(port); } \
> +    int  s5p_serial##port##_tstc(void) { \
> +	return serial_tstc_dev(port); } \
> +    void s5p_serial##port##_putc(const char c) { \
> +	serial_putc_dev(port, c); } \
> +    void s5p_serial##port##_puts(const char *s) { \
> +	serial_puts_dev(port, s); }

Mixing whitespace blanks and tabs.
Please convert to tabs.

> +
> +#define INIT_S5P_SERIAL_STRUCTURE(port, name, bus) { \
> +	name, \
> +	bus, \
> +	s5p_serial##port##_init, \
> +	s5p_serial##port##_setbrg, \
> +	s5p_serial##port##_getc, \
> +	s5p_serial##port##_tstc, \
> +	s5p_serial##port##_putc, \
> +	s5p_serial##port##_puts, }
> +#else
> +
> +#ifdef CONFIG_SERIAL0
> +#define UART_NR	S5PC1XX_UART0
> +#elif defined(CONFIG_SERIAL1)
> +#define UART_NR	S5PC1XX_UART1
> +#elif defined(CONFIG_SERIAL2)
> +#define UART_NR	S5PC1XX_UART2
> +#elif defined(CONFIG_SERIAL3)
> +#define UART_NR	S5PC1XX_UART3
> +#else
> +#error "Bad: you didn't configure serial ..."
> +#endif
> +
> +#endif /* CONFIG_SERIAL_MULTI */

Why do you need support two types of serial?

> +
> +static inline struct s5pc1xx_uart *s5pc1xx_get_base_uart(int dev_index)
> +{
> +	u32 offset = dev_index * sizeof(struct s5pc1xx_uart);
> +
> +	if (cpu_is_s5pc100())
> +		return (struct s5pc1xx_uart *)(S5PC100_UART_BASE + offset);
> +	else
> +		return (struct s5pc1xx_uart *)(S5PC110_UART_BASE + offset);
> +}
> +
> +/*
> + * The coefficient, used to calculate the baudrate on S5PC1XX UARTs is
> + * calculated as
> + * C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT
> + * however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1,
> + * 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants:
> + */
Good comment

> +static const int udivslot[] = {
> +	0,
> +	0x0080,
> +	0x0808,
> +	0x0888,
> +	0x2222,
> +	0x4924,
> +	0x4a52,
> +	0x54aa,
> +	0x5555,
> +	0xd555,
> +	0xd5d5,
> +	0xddd5,
> +	0xdddd,
> +	0xdfdd,
> +	0xdfdf,
> +	0xffdf,
> +};
> +
> +void _serial_setbrg(const int dev_index)
> +{
> +	DECLARE_GLOBAL_DATA_PTR;
> +	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
> +	u32 pclk = get_pclk();
> +	u32 baudrate = gd->baudrate;
> +	u32 val;
> +
> +	val = pclk / baudrate;
> +
> +	writel(val / 16 - 1, &uart->ubrdiv);
> +	writel(udivslot[val % 16], &uart->udivslot);
> +}
> +
> +#if defined(CONFIG_SERIAL_MULTI)
> +static inline void serial_setbrg_dev(unsigned int dev_index)
> +{
> +	_serial_setbrg(dev_index);
> +}
> +#else
> +void serial_setbrg(void)
> +{
> +	_serial_setbrg(UART_NR);
> +}
> +#endif
> +
> +/*
> + * 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_dev(const int dev_index)
> +{
> +	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
> +
> +	/* reset and enable FIFOs, set triggers to the maximum */
> +	writel(0, &uart->ufcon);
> +	writel(0, &uart->umcon);
> +	/* 8N1 */
> +	writel(0x3, &uart->ulcon);
> +	/* No interrupts, no DMA, pure polling */
> +	writel(0x245, &uart->ucon);
> +
> +	_serial_setbrg(dev_index);
> +
> +	return 0;
> +}
> +
> +#if !defined(CONFIG_SERIAL_MULTI)
> +int serial_init(void)
> +{
> +	return serial_init_dev(UART_NR);
> +}
> +#endif
> +
> +/*
> + * 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(const int dev_index)
> +{
> +	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
> +
> +	/* wait for character to arrive */
> +	while (!(readl(&uart->utrstat) & 0x1))
> +		;

Will this block ?

> +
> +	return (int)(readl(&uart->urxh) & 0xff);
> +}
> +
> +#if defined(CONFIG_SERIAL_MULTI)
> +static inline int serial_getc_dev(unsigned int dev_index)
> +{
> +	return _serial_getc(dev_index);
> +}
> +#else
> +int serial_getc(void)
> +{
> +	return _serial_getc(UART_NR);
> +}
> +#endif
> +
> +#ifdef CONFIG_MODEM_SUPPORT
> +static int be_quiet;
> +void disable_putc(void)
> +{
> +	be_quiet = 1;
> +}
> +
> +void enable_putc(void)
> +{
> +	be_quiet = 0;
> +}
> +#endif

Where is CONFIG_MODEM_SUPPORT used ?
There should be #define stubs for the non-modem case if these are to 
exported.
Also externals should be in a H file.

> +
> +/*
> + * Output a single byte to the serial port.
> + */
> +void _serial_putc(const char c, const int dev_index)
> +{
> +	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
> +
> +#ifdef CONFIG_MODEM_SUPPORT
> +	if (be_quiet)
> +		return;
> +#endif

The CONFIG_MODEM_SUPPORT is not needed.
The non-modem case does not change the state of the be_quiet.

> +
> +	/* wait for room in the tx FIFO */
> +	while (!(readl(&uart->utrstat) & 0x2))
> +		;
> +
> +	writel(c, &uart->utxh);
> +
> +	/* If \n, also do \r */
> +	if (c == '\n')
> +		serial_putc('\r');
> +}
> +
> +#if defined(CONFIG_SERIAL_MULTI)
> +static inline void serial_putc_dev(unsigned int dev_index, const char c)
> +{
> +	_serial_putc(c, dev_index);
> +}
> +#else
> +void serial_putc(const char c)
> +{
> +	_serial_putc(c, UART_NR);
> +}
> +#endif
> +
> +/*
> + * Test whether a character is in the RX buffer
> + */
> +int _serial_tstc(const int dev_index)
> +{
> +	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
> +
> +	return (int)(readl(&uart->utrstat) & 0x1);
> +}
> +
> +#if defined(CONFIG_SERIAL_MULTI)
> +static inline int serial_tstc_dev(unsigned int dev_index)
> +{
> +	return _serial_tstc(dev_index);
> +}
> +#else
> +int serial_tstc(void)
> +{
> +	return _serial_tstc(UART_NR);
> +}
> +#endif
> +
> +void _serial_puts(const char *s, const int dev_index)
> +{
> +	while (*s)
> +		_serial_putc(*s++, dev_index);
> +}
> +
> +#if defined(CONFIG_SERIAL_MULTI)
> +static inline void serial_puts_dev(int dev_index, const char *s)
> +{
> +	_serial_puts(s, dev_index);
> +}
> +#else
> +void serial_puts(const char *s)
> +{
> +	_serial_puts(s, UART_NR);
> +}
> +#endif
> +
> +#ifdef CONFIG_HWFLOW
> +static int hwflow;             /* turned off by default */

tab before comment, here and other places.

> +int hwflow_onoff(int on)
> +{
> +	switch (on) {
> +	case 1:
> +		hwflow = 1;     /* turn on */
> +		break;
> +	case -1:
> +		hwflow = 0;     /* turn off */
> +		break;
> +	}
> +	return hwflow;
> +}
> +#endif

Similar to the CONFIG_MODEM_SUPPORT.
Add #define stubs for non-hwflow
Add decl to H file

Tom



> +
> +#if defined(CONFIG_SERIAL_MULTI)
> +DECLARE_S5P_SERIAL_FUNCTIONS(0);
> +struct serial_device s5pc1xx_serial0_device =
> +	INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0", "S5PUART0");
> +DECLARE_S5P_SERIAL_FUNCTIONS(1);
> +struct serial_device s5pc1xx_serial1_device =
> +	INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1", "S5PUART1");
> +DECLARE_S5P_SERIAL_FUNCTIONS(2);
> +struct serial_device s5pc1xx_serial2_device =
> +	INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2", "S5PUART2");
> +DECLARE_S5P_SERIAL_FUNCTIONS(3);
> +struct serial_device s5pc1xx_serial3_device =
> +	INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3", "S5PUART3");
> +#endif
> diff --git a/include/serial.h b/include/serial.h
> index 821b583..bbda3f0 100644
> --- a/include/serial.h
> +++ b/include/serial.h
> @@ -43,6 +43,13 @@ extern struct serial_device s3c24xx_serial1_device;
>  extern struct serial_device s3c24xx_serial2_device;
>  #endif
>  
> +#if defined(CONFIG_S5PC1XX)
> +extern struct serial_device s5pc1xx_serial0_device;
> +extern struct serial_device s5pc1xx_serial1_device;
> +extern struct serial_device s5pc1xx_serial2_device;
> +extern struct serial_device s5pc1xx_serial3_device;
> +#endif
> +
>  #if defined(CONFIG_OMAP3_ZOOM2)
>  extern struct serial_device zoom2_serial_device0;
>  extern struct serial_device zoom2_serial_device1;