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_dev(struct udevice *dev, char ch) 87 { 88 struct dm_serial_ops *ops = serial_get_ops(cur_dev); 89 int err; 90 91 do { 92 err = ops->putc(cur_dev, ch); 93 } while (err == -EAGAIN); 94 if (ch == '\n') 95 serial_putc('\r'); 96 } 97 98 void serial_putc(char ch) 99 { 100 serial_putc_dev(cur_dev, ch); 101 } 102 103 void serial_setbrg(void) 104 { 105 struct dm_serial_ops *ops = serial_get_ops(cur_dev); 106 107 if (ops->setbrg) 108 ops->setbrg(cur_dev, gd->baudrate); 109 } 110 111 void serial_puts(const char *str) 112 { 113 while (*str) 114 serial_putc(*str++); 115 } 116 117 int serial_tstc(void) 118 { 119 struct dm_serial_ops *ops = serial_get_ops(cur_dev); 120 121 if (ops->pending) 122 return ops->pending(cur_dev, true); 123 124 return 1; 125 } 126 127 static int serial_getc_dev(struct udevice *dev) 128 { 129 struct dm_serial_ops *ops = serial_get_ops(dev); 130 int err; 131 132 do { 133 err = ops->getc(dev); 134 if (err == -EAGAIN) 135 WATCHDOG_RESET(); 136 } while (err == -EAGAIN); 137 138 return err >= 0 ? err : 0; 139 } 140 141 int serial_getc(void) 142 { 143 return serial_getc_dev(cur_dev); 144 } 145 146 void serial_stdio_init(void) 147 { 148 } 149 150 static void serial_stub_putc(struct stdio_dev *sdev, const char ch) 151 { 152 struct udevice *dev = sdev->priv; 153 154 serial_putc_dev(dev, ch); 155 } 156 157 void serial_stub_puts(struct stdio_dev *sdev, const char *str) 158 { 159 while (*str) 160 serial_stub_putc(sdev, *str++); 161 } 162 163 int serial_stub_getc(struct stdio_dev *sdev) 164 { 165 struct udevice *dev = sdev->priv; 166 167 return serial_getc_dev(dev); 168 } 169 170 int serial_stub_tstc(struct stdio_dev *sdev) 171 { 172 struct udevice *dev = sdev->priv; 173 struct dm_serial_ops *ops = serial_get_ops(dev); 174 175 if (ops->pending) 176 return ops->pending(dev, true); 177 178 return 1; 179 } 180 181 static int serial_post_probe(struct udevice *dev) 182 { 183 struct stdio_dev sdev; 184 struct dm_serial_ops *ops = serial_get_ops(dev); 185 struct serial_dev_priv *upriv = dev->uclass_priv; 186 int ret; 187 188 /* Set the baud rate */ 189 if (ops->setbrg) { 190 ret = ops->setbrg(dev, gd->baudrate); 191 if (ret) 192 return ret; 193 } 194 195 if (!(gd->flags & GD_FLG_RELOC)) 196 return 0; 197 198 memset(&sdev, '\0', sizeof(sdev)); 199 200 strncpy(sdev.name, dev->name, sizeof(sdev.name)); 201 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT; 202 sdev.priv = dev; 203 sdev.putc = serial_stub_putc; 204 sdev.puts = serial_stub_puts; 205 sdev.getc = serial_stub_getc; 206 sdev.tstc = serial_stub_tstc; 207 stdio_register_dev(&sdev, &upriv->sdev); 208 209 return 0; 210 } 211 212 static int serial_pre_remove(struct udevice *dev) 213 { 214 #ifdef CONFIG_SYS_STDIO_DEREGISTER 215 struct serial_dev_priv *upriv = dev->uclass_priv; 216 217 if (stdio_deregister_dev(upriv->sdev, 0)) 218 return -EPERM; 219 #endif 220 221 return 0; 222 } 223 224 UCLASS_DRIVER(serial) = { 225 .id = UCLASS_SERIAL, 226 .name = "serial", 227 .post_probe = serial_post_probe, 228 .pre_remove = serial_pre_remove, 229 .per_device_auto_alloc_size = sizeof(struct serial_dev_priv), 230 }; 231