1 /* 2 * Copyright (c) 2014 The Chromium OS Authors. 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <dm.h> 9 #include <environment.h> 10 #include <errno.h> 11 #include <fdtdec.h> 12 #include <os.h> 13 #include <serial.h> 14 #include <stdio_dev.h> 15 #include <watchdog.h> 16 #include <dm/lists.h> 17 #include <dm/device-internal.h> 18 19 DECLARE_GLOBAL_DATA_PTR; 20 21 /* 22 * Table with supported baudrates (defined in config_xyz.h) 23 */ 24 static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE; 25 26 #ifndef CONFIG_SYS_MALLOC_F_LEN 27 #error "Serial is required before relocation - define CONFIG_SYS_MALLOC_F_LEN to make this work" 28 #endif 29 30 static void serial_find_console_or_panic(void) 31 { 32 struct udevice *dev; 33 int node; 34 35 if (OF_CONTROL && gd->fdt_blob) { 36 /* Check for a chosen console */ 37 node = fdtdec_get_chosen_node(gd->fdt_blob, "stdout-path"); 38 if (node < 0) 39 node = fdt_path_offset(gd->fdt_blob, "console"); 40 if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, 41 &dev)) { 42 gd->cur_serial_dev = dev; 43 return; 44 } 45 46 /* 47 * If the console is not marked to be bound before relocation, 48 * bind it anyway. 49 */ 50 if (node > 0 && 51 !lists_bind_fdt(gd->dm_root, gd->fdt_blob, node, &dev)) { 52 if (!device_probe(dev)) { 53 gd->cur_serial_dev = dev; 54 return; 55 } 56 } 57 } 58 if (!SPL_BUILD || !OF_CONTROL || !gd->fdt_blob) { 59 /* 60 * Try to use CONFIG_CONS_INDEX if available (it is numbered 61 * from 1!). 62 * 63 * Failing that, get the device with sequence number 0, or in 64 * extremis just the first serial device we can find. But we 65 * insist on having a console (even if it is silent). 66 */ 67 #ifdef CONFIG_CONS_INDEX 68 #define INDEX (CONFIG_CONS_INDEX - 1) 69 #else 70 #define INDEX 0 71 #endif 72 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) || 73 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) || 74 (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) { 75 gd->cur_serial_dev = dev; 76 return; 77 } 78 #undef INDEX 79 } 80 81 panic_str("No serial driver found"); 82 } 83 84 /* Called prior to relocation */ 85 int serial_init(void) 86 { 87 serial_find_console_or_panic(); 88 gd->flags |= GD_FLG_SERIAL_READY; 89 90 return 0; 91 } 92 93 /* Called after relocation */ 94 void serial_initialize(void) 95 { 96 serial_find_console_or_panic(); 97 } 98 99 static void _serial_putc(struct udevice *dev, char ch) 100 { 101 struct dm_serial_ops *ops = serial_get_ops(dev); 102 int err; 103 104 do { 105 err = ops->putc(dev, ch); 106 } while (err == -EAGAIN); 107 if (ch == '\n') 108 _serial_putc(dev, '\r'); 109 } 110 111 static void _serial_puts(struct udevice *dev, const char *str) 112 { 113 while (*str) 114 _serial_putc(dev, *str++); 115 } 116 117 static int _serial_getc(struct udevice *dev) 118 { 119 struct dm_serial_ops *ops = serial_get_ops(dev); 120 int err; 121 122 do { 123 err = ops->getc(dev); 124 if (err == -EAGAIN) 125 WATCHDOG_RESET(); 126 } while (err == -EAGAIN); 127 128 return err >= 0 ? err : 0; 129 } 130 131 static int _serial_tstc(struct udevice *dev) 132 { 133 struct dm_serial_ops *ops = serial_get_ops(dev); 134 135 if (ops->pending) 136 return ops->pending(dev, true); 137 138 return 1; 139 } 140 141 void serial_putc(char ch) 142 { 143 _serial_putc(gd->cur_serial_dev, ch); 144 } 145 146 void serial_puts(const char *str) 147 { 148 _serial_puts(gd->cur_serial_dev, str); 149 } 150 151 int serial_getc(void) 152 { 153 return _serial_getc(gd->cur_serial_dev); 154 } 155 156 int serial_tstc(void) 157 { 158 return _serial_tstc(gd->cur_serial_dev); 159 } 160 161 void serial_setbrg(void) 162 { 163 struct dm_serial_ops *ops = serial_get_ops(gd->cur_serial_dev); 164 165 if (ops->setbrg) 166 ops->setbrg(gd->cur_serial_dev, gd->baudrate); 167 } 168 169 void serial_stdio_init(void) 170 { 171 } 172 173 #ifdef CONFIG_DM_STDIO 174 static void serial_stub_putc(struct stdio_dev *sdev, const char ch) 175 { 176 _serial_putc(sdev->priv, ch); 177 } 178 #endif 179 180 void serial_stub_puts(struct stdio_dev *sdev, const char *str) 181 { 182 _serial_puts(sdev->priv, str); 183 } 184 185 int serial_stub_getc(struct stdio_dev *sdev) 186 { 187 return _serial_getc(sdev->priv); 188 } 189 190 int serial_stub_tstc(struct stdio_dev *sdev) 191 { 192 return _serial_tstc(sdev->priv); 193 } 194 195 /** 196 * on_baudrate() - Update the actual baudrate when the env var changes 197 * 198 * This will check for a valid baudrate and only apply it if valid. 199 */ 200 static int on_baudrate(const char *name, const char *value, enum env_op op, 201 int flags) 202 { 203 int i; 204 int baudrate; 205 206 switch (op) { 207 case env_op_create: 208 case env_op_overwrite: 209 /* 210 * Switch to new baudrate if new baudrate is supported 211 */ 212 baudrate = simple_strtoul(value, NULL, 10); 213 214 /* Not actually changing */ 215 if (gd->baudrate == baudrate) 216 return 0; 217 218 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) { 219 if (baudrate == baudrate_table[i]) 220 break; 221 } 222 if (i == ARRAY_SIZE(baudrate_table)) { 223 if ((flags & H_FORCE) == 0) 224 printf("## Baudrate %d bps not supported\n", 225 baudrate); 226 return 1; 227 } 228 if ((flags & H_INTERACTIVE) != 0) { 229 printf("## Switch baudrate to %d bps and press ENTER ...\n", 230 baudrate); 231 udelay(50000); 232 } 233 234 gd->baudrate = baudrate; 235 236 serial_setbrg(); 237 238 udelay(50000); 239 240 if ((flags & H_INTERACTIVE) != 0) 241 while (1) { 242 if (getc() == '\r') 243 break; 244 } 245 246 return 0; 247 case env_op_delete: 248 printf("## Baudrate may not be deleted\n"); 249 return 1; 250 default: 251 return 0; 252 } 253 } 254 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate); 255 256 static int serial_post_probe(struct udevice *dev) 257 { 258 struct dm_serial_ops *ops = serial_get_ops(dev); 259 #ifdef CONFIG_DM_STDIO 260 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev); 261 struct stdio_dev sdev; 262 #endif 263 int ret; 264 265 #if defined(CONFIG_NEEDS_MANUAL_RELOC) 266 if (ops->setbrg) 267 ops->setbrg += gd->reloc_off; 268 if (ops->getc) 269 ops->getc += gd->reloc_off; 270 if (ops->putc) 271 ops->putc += gd->reloc_off; 272 if (ops->pending) 273 ops->pending += gd->reloc_off; 274 if (ops->clear) 275 ops->clear += gd->reloc_off; 276 #if CONFIG_POST & CONFIG_SYS_POST_UART 277 if (ops->loop) 278 ops->loop += gd->reloc_off 279 #endif 280 #endif 281 /* Set the baud rate */ 282 if (ops->setbrg) { 283 ret = ops->setbrg(dev, gd->baudrate); 284 if (ret) 285 return ret; 286 } 287 288 #ifdef CONFIG_DM_STDIO 289 if (!(gd->flags & GD_FLG_RELOC)) 290 return 0; 291 memset(&sdev, '\0', sizeof(sdev)); 292 293 strncpy(sdev.name, dev->name, sizeof(sdev.name)); 294 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT; 295 sdev.priv = dev; 296 sdev.putc = serial_stub_putc; 297 sdev.puts = serial_stub_puts; 298 sdev.getc = serial_stub_getc; 299 sdev.tstc = serial_stub_tstc; 300 stdio_register_dev(&sdev, &upriv->sdev); 301 #endif 302 return 0; 303 } 304 305 static int serial_pre_remove(struct udevice *dev) 306 { 307 #ifdef CONFIG_SYS_STDIO_DEREGISTER 308 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev); 309 310 if (stdio_deregister_dev(upriv->sdev, 0)) 311 return -EPERM; 312 #endif 313 314 return 0; 315 } 316 317 UCLASS_DRIVER(serial) = { 318 .id = UCLASS_SERIAL, 319 .name = "serial", 320 .flags = DM_UC_FLAG_SEQ_ALIAS, 321 .post_probe = serial_post_probe, 322 .pre_remove = serial_pre_remove, 323 .per_device_auto_alloc_size = sizeof(struct serial_dev_priv), 324 }; 325