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 <fdtdec.h> 26 #include <linux/compiler.h> 27 #include <asm/io.h> 28 #include <asm/arch/uart.h> 29 #include <asm/arch/clk.h> 30 #include <serial.h> 31 32 DECLARE_GLOBAL_DATA_PTR; 33 34 #define RX_FIFO_COUNT_MASK 0xff 35 #define RX_FIFO_FULL_MASK (1 << 8) 36 #define TX_FIFO_FULL_MASK (1 << 24) 37 38 /* Information about a serial port */ 39 struct fdt_serial { 40 u32 base_addr; /* address of registers in physical memory */ 41 u8 port_id; /* uart port number */ 42 u8 enabled; /* 1 if enabled, 0 if disabled */ 43 } config __attribute__ ((section(".data"))); 44 45 static inline struct s5p_uart *s5p_get_base_uart(int dev_index) 46 { 47 #ifdef CONFIG_OF_CONTROL 48 return (struct s5p_uart *)(config.base_addr); 49 #else 50 u32 offset = dev_index * sizeof(struct s5p_uart); 51 return (struct s5p_uart *)(samsung_get_base_uart() + offset); 52 #endif 53 } 54 55 /* 56 * The coefficient, used to calculate the baudrate on S5P UARTs is 57 * calculated as 58 * C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT 59 * however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1, 60 * 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants: 61 */ 62 static const int udivslot[] = { 63 0, 64 0x0080, 65 0x0808, 66 0x0888, 67 0x2222, 68 0x4924, 69 0x4a52, 70 0x54aa, 71 0x5555, 72 0xd555, 73 0xd5d5, 74 0xddd5, 75 0xdddd, 76 0xdfdd, 77 0xdfdf, 78 0xffdf, 79 }; 80 81 void serial_setbrg_dev(const int dev_index) 82 { 83 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 84 u32 uclk = get_uart_clk(dev_index); 85 u32 baudrate = gd->baudrate; 86 u32 val; 87 88 #if defined(CONFIG_SILENT_CONSOLE) && \ 89 defined(CONFIG_OF_CONTROL) && \ 90 !defined(CONFIG_SPL_BUILD) 91 if (fdtdec_get_config_int(gd->fdt_blob, "silent_console", 0)) 92 gd->flags |= GD_FLG_SILENT; 93 #endif 94 95 if (!config.enabled) 96 return; 97 98 val = uclk / baudrate; 99 100 writel(val / 16 - 1, &uart->ubrdiv); 101 102 if (s5p_uart_divslot()) 103 writew(udivslot[val % 16], &uart->rest.slot); 104 else 105 writeb(val % 16, &uart->rest.value); 106 } 107 108 /* 109 * Initialise the serial port with the given baudrate. The settings 110 * are always 8 data bits, no parity, 1 stop bit, no start bits. 111 */ 112 int serial_init_dev(const int dev_index) 113 { 114 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 115 116 /* enable FIFOs */ 117 writel(0x1, &uart->ufcon); 118 writel(0, &uart->umcon); 119 /* 8N1 */ 120 writel(0x3, &uart->ulcon); 121 /* No interrupts, no DMA, pure polling */ 122 writel(0x245, &uart->ucon); 123 124 serial_setbrg_dev(dev_index); 125 126 return 0; 127 } 128 129 static int serial_err_check(const int dev_index, int op) 130 { 131 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 132 unsigned int mask; 133 134 /* 135 * UERSTAT 136 * Break Detect [3] 137 * Frame Err [2] : receive operation 138 * Parity Err [1] : receive operation 139 * Overrun Err [0] : receive operation 140 */ 141 if (op) 142 mask = 0x8; 143 else 144 mask = 0xf; 145 146 return readl(&uart->uerstat) & mask; 147 } 148 149 /* 150 * Read a single byte from the serial port. Returns 1 on success, 0 151 * otherwise. When the function is succesfull, the character read is 152 * written into its argument c. 153 */ 154 int serial_getc_dev(const int dev_index) 155 { 156 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 157 158 if (!config.enabled) 159 return 0; 160 161 /* wait for character to arrive */ 162 while (!(readl(&uart->ufstat) & (RX_FIFO_COUNT_MASK | 163 RX_FIFO_FULL_MASK))) { 164 if (serial_err_check(dev_index, 0)) 165 return 0; 166 } 167 168 return (int)(readb(&uart->urxh) & 0xff); 169 } 170 171 /* 172 * Output a single byte to the serial port. 173 */ 174 void serial_putc_dev(const char c, const int dev_index) 175 { 176 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 177 178 if (!config.enabled) 179 return; 180 181 /* wait for room in the tx FIFO */ 182 while ((readl(&uart->ufstat) & TX_FIFO_FULL_MASK)) { 183 if (serial_err_check(dev_index, 1)) 184 return; 185 } 186 187 writeb(c, &uart->utxh); 188 189 /* If \n, also do \r */ 190 if (c == '\n') 191 serial_putc('\r'); 192 } 193 194 /* 195 * Test whether a character is in the RX buffer 196 */ 197 int serial_tstc_dev(const int dev_index) 198 { 199 struct s5p_uart *const uart = s5p_get_base_uart(dev_index); 200 201 if (!config.enabled) 202 return 0; 203 204 return (int)(readl(&uart->utrstat) & 0x1); 205 } 206 207 void serial_puts_dev(const char *s, const int dev_index) 208 { 209 while (*s) 210 serial_putc_dev(*s++, dev_index); 211 } 212 213 /* Multi serial device functions */ 214 #define DECLARE_S5P_SERIAL_FUNCTIONS(port) \ 215 int s5p_serial##port##_init(void) { return serial_init_dev(port); } \ 216 void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \ 217 int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \ 218 int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \ 219 void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \ 220 void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); } 221 222 #define INIT_S5P_SERIAL_STRUCTURE(port, __name) { \ 223 .name = __name, \ 224 .start = s5p_serial##port##_init, \ 225 .stop = NULL, \ 226 .setbrg = s5p_serial##port##_setbrg, \ 227 .getc = s5p_serial##port##_getc, \ 228 .tstc = s5p_serial##port##_tstc, \ 229 .putc = s5p_serial##port##_putc, \ 230 .puts = s5p_serial##port##_puts, \ 231 } 232 233 DECLARE_S5P_SERIAL_FUNCTIONS(0); 234 struct serial_device s5p_serial0_device = 235 INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0"); 236 DECLARE_S5P_SERIAL_FUNCTIONS(1); 237 struct serial_device s5p_serial1_device = 238 INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1"); 239 DECLARE_S5P_SERIAL_FUNCTIONS(2); 240 struct serial_device s5p_serial2_device = 241 INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2"); 242 DECLARE_S5P_SERIAL_FUNCTIONS(3); 243 struct serial_device s5p_serial3_device = 244 INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3"); 245 246 #ifdef CONFIG_OF_CONTROL 247 int fdtdec_decode_console(int *index, struct fdt_serial *uart) 248 { 249 const void *blob = gd->fdt_blob; 250 int node; 251 252 node = fdt_path_offset(blob, "console"); 253 if (node < 0) 254 return node; 255 256 uart->base_addr = fdtdec_get_addr(blob, node, "reg"); 257 if (uart->base_addr == FDT_ADDR_T_NONE) 258 return -FDT_ERR_NOTFOUND; 259 260 uart->port_id = fdtdec_get_int(blob, node, "id", -1); 261 uart->enabled = fdtdec_get_is_enabled(blob, node); 262 263 return 0; 264 } 265 #endif 266 267 __weak struct serial_device *default_serial_console(void) 268 { 269 #ifdef CONFIG_OF_CONTROL 270 int index = 0; 271 272 if ((!config.base_addr) && (fdtdec_decode_console(&index, &config))) { 273 debug("Cannot decode default console node\n"); 274 return NULL; 275 } 276 277 switch (config.port_id) { 278 case 0: 279 return &s5p_serial0_device; 280 case 1: 281 return &s5p_serial1_device; 282 case 2: 283 return &s5p_serial2_device; 284 case 3: 285 return &s5p_serial3_device; 286 default: 287 debug("Unknown config.port_id: %d", config.port_id); 288 break; 289 } 290 291 return NULL; 292 #else 293 config.enabled = 1; 294 #if defined(CONFIG_SERIAL0) 295 return &s5p_serial0_device; 296 #elif defined(CONFIG_SERIAL1) 297 return &s5p_serial1_device; 298 #elif defined(CONFIG_SERIAL2) 299 return &s5p_serial2_device; 300 #elif defined(CONFIG_SERIAL3) 301 return &s5p_serial3_device; 302 #else 303 #error "CONFIG_SERIAL? missing." 304 #endif 305 #endif 306 } 307 308 void s5p_serial_initialize(void) 309 { 310 serial_register(&s5p_serial0_device); 311 serial_register(&s5p_serial1_device); 312 serial_register(&s5p_serial2_device); 313 serial_register(&s5p_serial3_device); 314 } 315