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/*
* (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 <linux/compiler.h>
#include <asm/io.h>
#include <asm/arch/uart.h>
#include <asm/arch/clk.h>
#include <serial.h>
DECLARE_GLOBAL_DATA_PTR;
static inline struct s5p_uart *s5p_get_base_uart(int dev_index)
{
u32 offset = dev_index * sizeof(struct s5p_uart);
return (struct s5p_uart *)(samsung_get_base_uart() + offset);
}
/*
* 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,
};
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;
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.
*/
int serial_init_dev(const int dev_index)
{
struct s5p_uart *const uart = s5p_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(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.
*/
int serial_getc_dev(const int dev_index)
{
struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
/* wait for character to arrive */
while (!(readl(&uart->utrstat) & 0x1)) {
if (serial_err_check(dev_index, 0))
return 0;
}
return (int)(readb(&uart->urxh) & 0xff);
}
/*
* Output a single byte to the serial port.
*/
void serial_putc_dev(const char c, const int dev_index)
{
struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
/* wait for room in the tx FIFO */
while (!(readl(&uart->utrstat) & 0x2)) {
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
*/
int serial_tstc_dev(const int dev_index)
{
struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
return (int)(readl(&uart->utrstat) & 0x1);
}
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) \
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(c, port); } \
void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); }
#define INIT_S5P_SERIAL_STRUCTURE(port, name) { \
name, \
s5p_serial##port##_init, \
NULL, \
s5p_serial##port##_setbrg, \
s5p_serial##port##_getc, \
s5p_serial##port##_tstc, \
s5p_serial##port##_putc, \
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");
__weak struct serial_device *default_serial_console(void)
{
#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
}
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