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