diff options
Diffstat (limited to 'u-boot/drivers/serial/serial_s5p.c')
| -rw-r--r-- | u-boot/drivers/serial/serial_s5p.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/u-boot/drivers/serial/serial_s5p.c b/u-boot/drivers/serial/serial_s5p.c new file mode 100644 index 0000000..f1ffa29 --- /dev/null +++ b/u-boot/drivers/serial/serial_s5p.c @@ -0,0 +1,207 @@ +/* + * (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> +#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, bus) { \ + name, \ + bus, \ + 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", "S5PUART0"); +DECLARE_S5P_SERIAL_FUNCTIONS(1); +struct serial_device s5p_serial1_device = + INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1", "S5PUART1"); +DECLARE_S5P_SERIAL_FUNCTIONS(2); +struct serial_device s5p_serial2_device = + INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2", "S5PUART2"); +DECLARE_S5P_SERIAL_FUNCTIONS(3); +struct serial_device s5p_serial3_device = + INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3", "S5PUART3"); |