drivers/serial/sandbox.c

   1 /*
   2  * Copyright (c) 2011 The Chromium OS Authors.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 /*
   8  * This provide a test serial port. It provides an emulated serial port where
   9  * a test program and read out the serial output and inject serial input for
  10  * U-Boot.
  11  */
  12
  13 #include <common.h>
  14 #include <dm.h>
  15 #include <fdtdec.h>
  16 #include <lcd.h>
  17 #include <os.h>
  18 #include <serial.h>
  19 #include <linux/compiler.h>
  20 #include <asm/state.h>
  21
  22 DECLARE_GLOBAL_DATA_PTR;
  23
  24 /*
  25  *
  26  *   serial_buf: A buffer that holds keyboard characters for the
  27  *               Sandbox U-boot.
  28  *
  29  * invariants:
  30  *   serial_buf_write            == serial_buf_read -> empty buffer
  31  *   (serial_buf_write + 1) % 16 == serial_buf_read -> full buffer
  32  */
  33 static char serial_buf[16];
  34 static unsigned int serial_buf_write;
  35 static unsigned int serial_buf_read;
  36
  37 struct sandbox_serial_platdata {
  38         int colour;     /* Text colour to use for output, -1 for none */
  39 };
  40
  41 struct sandbox_serial_priv {
  42         bool start_of_line;
  43 };
  44
  45 /**
  46  * output_ansi_colour() - Output an ANSI colour code
  47  *
  48  * @colour: Colour to output (0-7)
  49  */
  50 static void output_ansi_colour(int colour)
  51 {
  52         char ansi_code[] = "\x1b[1;3Xm";
  53
  54         ansi_code[5] = '0' + colour;
  55         os_write(1, ansi_code, sizeof(ansi_code) - 1);
  56 }
  57
  58 static void output_ansi_reset(void)
  59 {
  60         os_write(1, "\x1b[0m", 4);
  61 }
  62
  63 static int sandbox_serial_probe(struct udevice *dev)
  64 {
  65         struct sandbox_state *state = state_get_current();
  66         struct sandbox_serial_priv *priv = dev_get_priv(dev);
  67
  68         if (state->term_raw != STATE_TERM_COOKED)
  69                 os_tty_raw(0, state->term_raw == STATE_TERM_RAW_WITH_SIGS);
  70         priv->start_of_line = 0;
  71
  72         return 0;
  73 }
  74
  75 static int sandbox_serial_remove(struct udevice *dev)
  76 {
  77         struct sandbox_serial_platdata *plat = dev->platdata;
  78
  79         if (plat->colour != -1)
  80                 output_ansi_reset();
  81
  82         return 0;
  83 }
  84
  85 static int sandbox_serial_putc(struct udevice *dev, const char ch)
  86 {
  87         struct sandbox_serial_priv *priv = dev_get_priv(dev);
  88         struct sandbox_serial_platdata *plat = dev->platdata;
  89
  90         if (priv->start_of_line && plat->colour != -1) {
  91                 priv->start_of_line = false;
  92                 output_ansi_colour(plat->colour);
  93         }
  94
  95         os_write(1, &ch, 1);
  96         if (ch == '\n')
  97                 priv->start_of_line = true;
  98
  99         return 0;
 100 }
 101
 102 static unsigned int increment_buffer_index(unsigned int index)
 103 {
 104         return (index + 1) % ARRAY_SIZE(serial_buf);
 105 }
 106
 107 static int sandbox_serial_pending(struct udevice *dev, bool input)
 108 {
 109         const unsigned int next_index =
 110                 increment_buffer_index(serial_buf_write);
 111         ssize_t count;
 112
 113         if (!input)
 114                 return 0;
 115
 116         os_usleep(100);
 117 #ifdef CONFIG_LCD
 118         lcd_sync();
 119 #endif
 120         if (next_index == serial_buf_read)
 121                 return 1;       /* buffer full */
 122
 123         count = os_read_no_block(0, &serial_buf[serial_buf_write], 1);
 124         if (count == 1)
 125                 serial_buf_write = next_index;
 126
 127         return serial_buf_write != serial_buf_read;
 128 }
 129
 130 static int sandbox_serial_getc(struct udevice *dev)
 131 {
 132         int result;
 133
 134         if (!sandbox_serial_pending(dev, true))
 135                 return -EAGAIN; /* buffer empty */
 136
 137         result = serial_buf[serial_buf_read];
 138         serial_buf_read = increment_buffer_index(serial_buf_read);
 139         return result;
 140 }
 141
 142 static const char * const ansi_colour[] = {
 143         "black", "red", "green", "yellow", "blue", "megenta", "cyan",
 144         "white",
 145 };
 146
 147 static int sandbox_serial_ofdata_to_platdata(struct udevice *dev)
 148 {
 149         struct sandbox_serial_platdata *plat = dev->platdata;
 150         const char *colour;
 151         int i;
 152
 153         plat->colour = -1;
 154         colour = fdt_getprop(gd->fdt_blob, dev->of_offset,
 155                              "sandbox,text-colour", NULL);
 156         if (colour) {
 157                 for (i = 0; i < ARRAY_SIZE(ansi_colour); i++) {
 158                         if (!strcmp(colour, ansi_colour[i])) {
 159                                 plat->colour = i;
 160                                 break;
 161                         }
 162                 }
 163         }
 164
 165         return 0;
 166 }
 167
 168 static const struct dm_serial_ops sandbox_serial_ops = {
 169         .putc = sandbox_serial_putc,
 170         .pending = sandbox_serial_pending,
 171         .getc = sandbox_serial_getc,
 172 };
 173
 174 static const struct udevice_id sandbox_serial_ids[] = {
 175         { .compatible = "sandbox,serial" },
 176         { }
 177 };
 178
 179 U_BOOT_DRIVER(serial_sandbox) = {
 180         .name   = "serial_sandbox",
 181         .id     = UCLASS_SERIAL,
 182         .of_match = sandbox_serial_ids,
 183         .ofdata_to_platdata = sandbox_serial_ofdata_to_platdata,
 184         .platdata_auto_alloc_size = sizeof(struct sandbox_serial_platdata),
 185         .priv_auto_alloc_size = sizeof(struct sandbox_serial_priv),
 186         .probe = sandbox_serial_probe,
 187         .remove = sandbox_serial_remove,
 188         .ops    = &sandbox_serial_ops,
 189         .flags = DM_FLAG_PRE_RELOC,
 190 };
 191
 192 static const struct sandbox_serial_platdata platdata_non_fdt = {
 193         .colour = -1,
 194 };
 195
 196 U_BOOT_DEVICE(serial_sandbox_non_fdt) = {
 197         .name = "serial_sandbox",
 198         .platdata = &platdata_non_fdt,
 199 };