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 <errno.h> 10 #include <fdtdec.h> 11 #include <os.h> 12 #include <serial.h> 13 #include <stdio_dev.h> 14 #include <watchdog.h> 15 #include <dm/lists.h> 16 #include <dm/device-internal.h> 17 18 #include <ns16550.h> 19 20 DECLARE_GLOBAL_DATA_PTR; 21 22 /* The currently-selected console serial device */ 23 struct udevice *cur_dev __attribute__ ((section(".data"))); 24 25 #ifndef CONFIG_SYS_MALLOC_F_LEN 26 #error "Serial is required before relocation - define CONFIG_SYS_MALLOC_F_LEN to make this work" 27 #endif 28 29 static void serial_find_console_or_panic(void) 30 { 31 #ifdef CONFIG_OF_CONTROL 32 int node; 33 34 /* Check for a chosen console */ 35 node = fdtdec_get_chosen_node(gd->fdt_blob, "stdout-path"); 36 if (node < 0) 37 node = fdtdec_get_alias_node(gd->fdt_blob, "console"); 38 if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, &cur_dev)) 39 return; 40 41 /* 42 * If the console is not marked to be bound before relocation, bind 43 * it anyway. 44 */ 45 if (node > 0 && 46 !lists_bind_fdt(gd->dm_root, gd->fdt_blob, node, &cur_dev)) { 47 if (!device_probe(cur_dev)) 48 return; 49 cur_dev = NULL; 50 } 51 #endif 52 /* 53 * Try to use CONFIG_CONS_INDEX if available (it is numbered from 1!). 54 * 55 * Failing that, get the device with sequence number 0, or in extremis 56 * just the first serial device we can find. But we insist on having 57 * a console (even if it is silent). 58 */ 59 #ifdef CONFIG_CONS_INDEX 60 #define INDEX (CONFIG_CONS_INDEX - 1) 61 #else 62 #define INDEX 0 63 #endif 64 if (uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &cur_dev) && 65 uclass_get_device(UCLASS_SERIAL, INDEX, &cur_dev) && 66 (uclass_first_device(UCLASS_SERIAL, &cur_dev) || !cur_dev)) 67 panic("No serial driver found"); 68 #undef INDEX 69 } 70 71 /* Called prior to relocation */ 72 int serial_init(void) 73 { 74 serial_find_console_or_panic(); 75 gd->flags |= GD_FLG_SERIAL_READY; 76 77 return 0; 78 } 79 80 /* Called after relocation */ 81 void serial_initialize(void) 82 { 83 serial_find_console_or_panic(); 84 } 85 86 static void _serial_putc(struct udevice *dev, char ch) 87 { 88 struct dm_serial_ops *ops = serial_get_ops(dev); 89 int err; 90 91 do { 92 err = ops->putc(dev, ch); 93 } while (err == -EAGAIN); 94 if (ch == '\n') 95 _serial_putc(dev, '\r'); 96 } 97 98 static void _serial_puts(struct udevice *dev, const char *str) 99 { 100 while (*str) 101 _serial_putc(dev, *str++); 102 } 103 104 static int _serial_getc(struct udevice *dev) 105 { 106 struct dm_serial_ops *ops = serial_get_ops(dev); 107 int err; 108 109 do { 110 err = ops->getc(dev); 111 if (err == -EAGAIN) 112 WATCHDOG_RESET(); 113 } while (err == -EAGAIN); 114 115 return err >= 0 ? err : 0; 116 } 117 118 static int _serial_tstc(struct udevice *dev) 119 { 120 struct dm_serial_ops *ops = serial_get_ops(dev); 121 122 if (ops->pending) 123 return ops->pending(dev, true); 124 125 return 1; 126 } 127 128 void serial_putc(char ch) 129 { 130 _serial_putc(cur_dev, ch); 131 } 132 133 void serial_puts(const char *str) 134 { 135 _serial_puts(cur_dev, str); 136 } 137 138 int serial_getc(void) 139 { 140 return _serial_getc(cur_dev); 141 } 142 143 int serial_tstc(void) 144 { 145 return _serial_tstc(cur_dev); 146 } 147 148 void serial_setbrg(void) 149 { 150 struct dm_serial_ops *ops = serial_get_ops(cur_dev); 151 152 if (ops->setbrg) 153 ops->setbrg(cur_dev, gd->baudrate); 154 } 155 156 void serial_stdio_init(void) 157 { 158 } 159 160 static void serial_stub_putc(struct stdio_dev *sdev, const char ch) 161 { 162 _serial_putc(sdev->priv, ch); 163 } 164 165 void serial_stub_puts(struct stdio_dev *sdev, const char *str) 166 { 167 _serial_puts(sdev->priv, str); 168 } 169 170 int serial_stub_getc(struct stdio_dev *sdev) 171 { 172 return _serial_getc(sdev->priv); 173 } 174 175 int serial_stub_tstc(struct stdio_dev *sdev) 176 { 177 return _serial_tstc(sdev->priv); 178 } 179 180 static int serial_post_probe(struct udevice *dev) 181 { 182 struct stdio_dev sdev; 183 struct dm_serial_ops *ops = serial_get_ops(dev); 184 struct serial_dev_priv *upriv = dev->uclass_priv; 185 int ret; 186 187 /* Set the baud rate */ 188 if (ops->setbrg) { 189 ret = ops->setbrg(dev, gd->baudrate); 190 if (ret) 191 return ret; 192 } 193 194 if (!(gd->flags & GD_FLG_RELOC)) 195 return 0; 196 197 memset(&sdev, '\0', sizeof(sdev)); 198 199 strncpy(sdev.name, dev->name, sizeof(sdev.name)); 200 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT; 201 sdev.priv = dev; 202 sdev.putc = serial_stub_putc; 203 sdev.puts = serial_stub_puts; 204 sdev.getc = serial_stub_getc; 205 sdev.tstc = serial_stub_tstc; 206 stdio_register_dev(&sdev, &upriv->sdev); 207 208 return 0; 209 } 210 211 static int serial_pre_remove(struct udevice *dev) 212 { 213 #ifdef CONFIG_SYS_STDIO_DEREGISTER 214 struct serial_dev_priv *upriv = dev->uclass_priv; 215 216 if (stdio_deregister_dev(upriv->sdev, 0)) 217 return -EPERM; 218 #endif 219 220 return 0; 221 } 222 223 UCLASS_DRIVER(serial) = { 224 .id = UCLASS_SERIAL, 225 .name = "serial", 226 .post_probe = serial_post_probe, 227 .pre_remove = serial_pre_remove, 228 .per_device_auto_alloc_size = sizeof(struct serial_dev_priv), 229 }; 230