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