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 * Failing that, get the device with sequence number 0, or in extremis 54 * just the first serial device we can find. But we insist on having 55 * a console (even if it is silent). 56 */ 57 if (uclass_get_device_by_seq(UCLASS_SERIAL, 0, &cur_dev) && 58 (uclass_first_device(UCLASS_SERIAL, &cur_dev) || !cur_dev)) 59 panic("No serial driver found"); 60 } 61 62 /* Called prior to relocation */ 63 int serial_init(void) 64 { 65 serial_find_console_or_panic(); 66 gd->flags |= GD_FLG_SERIAL_READY; 67 68 return 0; 69 } 70 71 /* Called after relocation */ 72 void serial_initialize(void) 73 { 74 serial_find_console_or_panic(); 75 } 76 77 static void serial_putc_dev(struct udevice *dev, char ch) 78 { 79 struct dm_serial_ops *ops = serial_get_ops(cur_dev); 80 int err; 81 82 do { 83 err = ops->putc(cur_dev, ch); 84 } while (err == -EAGAIN); 85 if (ch == '\n') 86 serial_putc('\r'); 87 } 88 89 void serial_putc(char ch) 90 { 91 serial_putc_dev(cur_dev, ch); 92 } 93 94 void serial_setbrg(void) 95 { 96 struct dm_serial_ops *ops = serial_get_ops(cur_dev); 97 98 if (ops->setbrg) 99 ops->setbrg(cur_dev, gd->baudrate); 100 } 101 102 void serial_puts(const char *str) 103 { 104 while (*str) 105 serial_putc(*str++); 106 } 107 108 int serial_tstc(void) 109 { 110 struct dm_serial_ops *ops = serial_get_ops(cur_dev); 111 112 if (ops->pending) 113 return ops->pending(cur_dev, true); 114 115 return 1; 116 } 117 118 static int serial_getc_dev(struct udevice *dev) 119 { 120 struct dm_serial_ops *ops = serial_get_ops(dev); 121 int err; 122 123 do { 124 err = ops->getc(dev); 125 if (err == -EAGAIN) 126 WATCHDOG_RESET(); 127 } while (err == -EAGAIN); 128 129 return err >= 0 ? err : 0; 130 } 131 132 int serial_getc(void) 133 { 134 return serial_getc_dev(cur_dev); 135 } 136 137 void serial_stdio_init(void) 138 { 139 } 140 141 static void serial_stub_putc(struct stdio_dev *sdev, const char ch) 142 { 143 struct udevice *dev = sdev->priv; 144 145 serial_putc_dev(dev, ch); 146 } 147 148 void serial_stub_puts(struct stdio_dev *sdev, const char *str) 149 { 150 while (*str) 151 serial_stub_putc(sdev, *str++); 152 } 153 154 int serial_stub_getc(struct stdio_dev *sdev) 155 { 156 struct udevice *dev = sdev->priv; 157 158 return serial_getc_dev(dev); 159 } 160 161 int serial_stub_tstc(struct stdio_dev *sdev) 162 { 163 struct udevice *dev = sdev->priv; 164 struct dm_serial_ops *ops = serial_get_ops(dev); 165 166 if (ops->pending) 167 return ops->pending(dev, true); 168 169 return 1; 170 } 171 172 static int serial_post_probe(struct udevice *dev) 173 { 174 struct stdio_dev sdev; 175 struct dm_serial_ops *ops = serial_get_ops(dev); 176 struct serial_dev_priv *upriv = dev->uclass_priv; 177 int ret; 178 179 /* Set the baud rate */ 180 if (ops->setbrg) { 181 ret = ops->setbrg(dev, gd->baudrate); 182 if (ret) 183 return ret; 184 } 185 186 if (!(gd->flags & GD_FLG_RELOC)) 187 return 0; 188 189 memset(&sdev, '\0', sizeof(sdev)); 190 191 strncpy(sdev.name, dev->name, sizeof(sdev.name)); 192 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT; 193 sdev.priv = dev; 194 sdev.putc = serial_stub_putc; 195 sdev.puts = serial_stub_puts; 196 sdev.getc = serial_stub_getc; 197 sdev.tstc = serial_stub_tstc; 198 stdio_register_dev(&sdev, &upriv->sdev); 199 200 return 0; 201 } 202 203 static int serial_pre_remove(struct udevice *dev) 204 { 205 #ifdef CONFIG_SYS_STDIO_DEREGISTER 206 struct serial_dev_priv *upriv = dev->uclass_priv; 207 208 if (stdio_deregister_dev(upriv->sdev, 0)) 209 return -EPERM; 210 #endif 211 212 return 0; 213 } 214 215 UCLASS_DRIVER(serial) = { 216 .id = UCLASS_SERIAL, 217 .name = "serial", 218 .post_probe = serial_post_probe, 219 .pre_remove = serial_pre_remove, 220 .per_device_auto_alloc_size = sizeof(struct serial_dev_priv), 221 }; 222