/* * (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 }