u-boot/drivers/serial/serial_s5p.c
Inha Song e6252fab2d serial: s5p: set automatically clears after resetting Rx FIFO
This patch fix the u-boot shell problem on TRATS2 board.
 - If hold the key while booting is in progress,
   white spaces are written in u-boot shell.

Set Automatically clears after resetting Rx FIFO.

Signed-off-by: Inha Song <ideal.song@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
2014-02-05 16:26:09 +09:00

301 lines
7 KiB
C

/*
* (C) Copyright 2009 SAMSUNG Electronics
* Minkyu Kang <mk7.kang@samsung.com>
* Heungjun Kim <riverful.kim@samsung.com>
*
* based on drivers/serial/s3c64xx.c
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <fdtdec.h>
#include <linux/compiler.h>
#include <asm/io.h>
#include <asm/arch/uart.h>
#include <asm/arch/clk.h>
#include <serial.h>
DECLARE_GLOBAL_DATA_PTR;
#define RX_FIFO_COUNT_MASK 0xff
#define RX_FIFO_FULL_MASK (1 << 8)
#define TX_FIFO_FULL_MASK (1 << 24)
/* Information about a serial port */
struct fdt_serial {
u32 base_addr; /* address of registers in physical memory */
u8 port_id; /* uart port number */
u8 enabled; /* 1 if enabled, 0 if disabled */
} config __attribute__ ((section(".data")));
static inline struct s5p_uart *s5p_get_base_uart(int dev_index)
{
#ifdef CONFIG_OF_CONTROL
return (struct s5p_uart *)(config.base_addr);
#else
u32 offset = dev_index * sizeof(struct s5p_uart);
return (struct s5p_uart *)(samsung_get_base_uart() + offset);
#endif
}
/*
* The coefficient, used to calculate the baudrate on S5P 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:
*/
static const int udivslot[] = {
0,
0x0080,
0x0808,
0x0888,
0x2222,
0x4924,
0x4a52,
0x54aa,
0x5555,
0xd555,
0xd5d5,
0xddd5,
0xdddd,
0xdfdd,
0xdfdf,
0xffdf,
};
static void serial_setbrg_dev(const int dev_index)
{
struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
u32 uclk = get_uart_clk(dev_index);
u32 baudrate = gd->baudrate;
u32 val;
#if defined(CONFIG_SILENT_CONSOLE) && \
defined(CONFIG_OF_CONTROL) && \
!defined(CONFIG_SPL_BUILD)
if (fdtdec_get_config_int(gd->fdt_blob, "silent_console", 0))
gd->flags |= GD_FLG_SILENT;
#endif
if (!config.enabled)
return;
val = uclk / baudrate;
writel(val / 16 - 1, &uart->ubrdiv);
if (s5p_uart_divslot())
writew(udivslot[val % 16], &uart->rest.slot);
else
writeb(val % 16, &uart->rest.value);
}
/*
* Initialise the serial port with the given baudrate. The settings
* are always 8 data bits, no parity, 1 stop bit, no start bits.
*/
static int serial_init_dev(const int dev_index)
{
struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
/* enable FIFOs, auto clear Rx FIFO */
writel(0x3, &uart->ufcon);
writel(0, &uart->umcon);
/* 8N1 */
writel(0x3, &uart->ulcon);
/* No interrupts, no DMA, pure polling */
writel(0x245, &uart->ucon);
serial_setbrg_dev(dev_index);
return 0;
}
static int serial_err_check(const int dev_index, int op)
{
struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
unsigned int mask;
/*
* UERSTAT
* Break Detect [3]
* Frame Err [2] : receive operation
* Parity Err [1] : receive operation
* Overrun Err [0] : receive operation
*/
if (op)
mask = 0x8;
else
mask = 0xf;
return readl(&uart->uerstat) & mask;
}
/*
* 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.
*/
static int serial_getc_dev(const int dev_index)
{
struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
if (!config.enabled)
return 0;
/* wait for character to arrive */
while (!(readl(&uart->ufstat) & (RX_FIFO_COUNT_MASK |
RX_FIFO_FULL_MASK))) {
if (serial_err_check(dev_index, 0))
return 0;
}
return (int)(readb(&uart->urxh) & 0xff);
}
/*
* Output a single byte to the serial port.
*/
static void serial_putc_dev(const char c, const int dev_index)
{
struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
if (!config.enabled)
return;
/* wait for room in the tx FIFO */
while ((readl(&uart->ufstat) & TX_FIFO_FULL_MASK)) {
if (serial_err_check(dev_index, 1))
return;
}
writeb(c, &uart->utxh);
/* If \n, also do \r */
if (c == '\n')
serial_putc('\r');
}
/*
* Test whether a character is in the RX buffer
*/
static int serial_tstc_dev(const int dev_index)
{
struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
if (!config.enabled)
return 0;
return (int)(readl(&uart->utrstat) & 0x1);
}
static void serial_puts_dev(const char *s, const int dev_index)
{
while (*s)
serial_putc_dev(*s++, dev_index);
}
/* Multi serial device functions */
#define DECLARE_S5P_SERIAL_FUNCTIONS(port) \
static int s5p_serial##port##_init(void) { return serial_init_dev(port); } \
static void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \
static int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \
static int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \
static void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \
static void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); }
#define INIT_S5P_SERIAL_STRUCTURE(port, __name) { \
.name = __name, \
.start = s5p_serial##port##_init, \
.stop = NULL, \
.setbrg = s5p_serial##port##_setbrg, \
.getc = s5p_serial##port##_getc, \
.tstc = s5p_serial##port##_tstc, \
.putc = s5p_serial##port##_putc, \
.puts = s5p_serial##port##_puts, \
}
DECLARE_S5P_SERIAL_FUNCTIONS(0);
struct serial_device s5p_serial0_device =
INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0");
DECLARE_S5P_SERIAL_FUNCTIONS(1);
struct serial_device s5p_serial1_device =
INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1");
DECLARE_S5P_SERIAL_FUNCTIONS(2);
struct serial_device s5p_serial2_device =
INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2");
DECLARE_S5P_SERIAL_FUNCTIONS(3);
struct serial_device s5p_serial3_device =
INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3");
#ifdef CONFIG_OF_CONTROL
int fdtdec_decode_console(int *index, struct fdt_serial *uart)
{
const void *blob = gd->fdt_blob;
int node;
node = fdt_path_offset(blob, "console");
if (node < 0)
return node;
uart->base_addr = fdtdec_get_addr(blob, node, "reg");
if (uart->base_addr == FDT_ADDR_T_NONE)
return -FDT_ERR_NOTFOUND;
uart->port_id = fdtdec_get_int(blob, node, "id", -1);
uart->enabled = fdtdec_get_is_enabled(blob, node);
return 0;
}
#endif
__weak struct serial_device *default_serial_console(void)
{
#ifdef CONFIG_OF_CONTROL
int index = 0;
if ((!config.base_addr) && (fdtdec_decode_console(&index, &config))) {
debug("Cannot decode default console node\n");
return NULL;
}
switch (config.port_id) {
case 0:
return &s5p_serial0_device;
case 1:
return &s5p_serial1_device;
case 2:
return &s5p_serial2_device;
case 3:
return &s5p_serial3_device;
default:
debug("Unknown config.port_id: %d", config.port_id);
break;
}
return NULL;
#else
config.enabled = 1;
#if defined(CONFIG_SERIAL0)
return &s5p_serial0_device;
#elif defined(CONFIG_SERIAL1)
return &s5p_serial1_device;
#elif defined(CONFIG_SERIAL2)
return &s5p_serial2_device;
#elif defined(CONFIG_SERIAL3)
return &s5p_serial3_device;
#else
#error "CONFIG_SERIAL? missing."
#endif
#endif
}
void s5p_serial_initialize(void)
{
serial_register(&s5p_serial0_device);
serial_register(&s5p_serial1_device);
serial_register(&s5p_serial2_device);
serial_register(&s5p_serial3_device);
}