1 /* 2 * (C) Copyright 2009 SAMSUNG Electronics 3 * Minkyu Kang <mk7.kang@samsung.com> 4 * Heungjun Kim <riverful.kim@samsung.com> 5 * 6 * based on drivers/serial/s3c64xx.c 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 */ 23 24 #include <common.h> 25 #include <asm/io.h> 26 #include <asm/arch/uart.h> 27 #include <asm/arch/clk.h> 28 #include <serial.h> 29 30 static inline struct s5p_uart *s5p_get_base_uart(int dev_index) 31 { 32 u32 offset = dev_index * sizeof(struct s5p_uart); 33 34 if (cpu_is_s5pc100()) 35 return (struct s5p_uart *)(S5PC100_UART_BASE + offset); 36 else 37 return (struct s5p_uart *)(S5PC110_UART_BASE + offset); 38 } 39 40 /* 41 * The coefficient, used to calculate the baudrate on S5P UARTs is 42 * calculated as 43 * C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT 44 * however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1, 45 * 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants: 46 */ 47 static const int udivslot[] = { 48 0, 49 0x0080, 50 0x0808, 51 0x0888, 52 0x2222, 53 0x4924, 54 0x4a52, 55 0x54aa, 56 0x5555, 57 0xd555, 58 0xd5d5, 59 0xddd5, 60 0xdddd, 61 0xdfdd, 62 0xdfdf, 63 0xffdf, 64 }; 65 66 void serial_setbrg_dev(const int dev_index) 67 { 68 DECLARE_GLOBAL_DATA_PTR; 69 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 70 u32 pclk = get_pclk(); 71 u32 baudrate = gd->baudrate; 72 u32 val; 73 74 val = pclk / baudrate; 75 76 writel(val / 16 - 1, &uart->ubrdiv); 77 writew(udivslot[val % 16], &uart->udivslot); 78 } 79 80 /* 81 * Initialise the serial port with the given baudrate. The settings 82 * are always 8 data bits, no parity, 1 stop bit, no start bits. 83 */ 84 int serial_init_dev(const int dev_index) 85 { 86 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 87 88 /* reset and enable FIFOs, set triggers to the maximum */ 89 writel(0, &uart->ufcon); 90 writel(0, &uart->umcon); 91 /* 8N1 */ 92 writel(0x3, &uart->ulcon); 93 /* No interrupts, no DMA, pure polling */ 94 writel(0x245, &uart->ucon); 95 96 serial_setbrg_dev(dev_index); 97 98 return 0; 99 } 100 101 static int serial_err_check(const int dev_index, int op) 102 { 103 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 104 unsigned int mask; 105 106 /* 107 * UERSTAT 108 * Break Detect [3] 109 * Frame Err [2] : receive operation 110 * Parity Err [1] : receive operation 111 * Overrun Err [0] : receive operation 112 */ 113 if (op) 114 mask = 0x8; 115 else 116 mask = 0xf; 117 118 return readl(&uart->uerstat) & mask; 119 } 120 121 /* 122 * Read a single byte from the serial port. Returns 1 on success, 0 123 * otherwise. When the function is succesfull, the character read is 124 * written into its argument c. 125 */ 126 int serial_getc_dev(const int dev_index) 127 { 128 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 129 130 /* wait for character to arrive */ 131 while (!(readl(&uart->utrstat) & 0x1)) { 132 if (serial_err_check(dev_index, 0)) 133 return 0; 134 } 135 136 return (int)(readl(&uart->urxh) & 0xff); 137 } 138 139 /* 140 * Output a single byte to the serial port. 141 */ 142 void serial_putc_dev(const char c, const int dev_index) 143 { 144 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 145 146 /* wait for room in the tx FIFO */ 147 while (!(readl(&uart->utrstat) & 0x2)) { 148 if (serial_err_check(dev_index, 1)) 149 return; 150 } 151 152 writel(c, &uart->utxh); 153 154 /* If \n, also do \r */ 155 if (c == '\n') 156 serial_putc('\r'); 157 } 158 159 /* 160 * Test whether a character is in the RX buffer 161 */ 162 int serial_tstc_dev(const int dev_index) 163 { 164 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 165 166 return (int)(readl(&uart->utrstat) & 0x1); 167 } 168 169 void serial_puts_dev(const char *s, const int dev_index) 170 { 171 while (*s) 172 serial_putc_dev(*s++, dev_index); 173 } 174 175 /* Multi serial device functions */ 176 #define DECLARE_S5P_SERIAL_FUNCTIONS(port) \ 177 int s5p_serial##port##_init(void) { return serial_init_dev(port); } \ 178 void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \ 179 int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \ 180 int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \ 181 void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \ 182 void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); } 183 184 #define INIT_S5P_SERIAL_STRUCTURE(port, name, bus) { \ 185 name, \ 186 bus, \ 187 s5p_serial##port##_init, \ 188 NULL, \ 189 s5p_serial##port##_setbrg, \ 190 s5p_serial##port##_getc, \ 191 s5p_serial##port##_tstc, \ 192 s5p_serial##port##_putc, \ 193 s5p_serial##port##_puts, } 194 195 DECLARE_S5P_SERIAL_FUNCTIONS(0); 196 struct serial_device s5p_serial0_device = 197 INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0", "S5PUART0"); 198 DECLARE_S5P_SERIAL_FUNCTIONS(1); 199 struct serial_device s5p_serial1_device = 200 INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1", "S5PUART1"); 201 DECLARE_S5P_SERIAL_FUNCTIONS(2); 202 struct serial_device s5p_serial2_device = 203 INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2", "S5PUART2"); 204 DECLARE_S5P_SERIAL_FUNCTIONS(3); 205 struct serial_device s5p_serial3_device = 206 INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3", "S5PUART3"); 207