drivers/serial/sandbox.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2011 The Chromium OS Authors.
   4  */
   5
   6 /*
   7  * This provide a test serial port. It provides an emulated serial port where
   8  * a test program and read out the serial output and inject serial input for
   9  * U-Boot.
  10  */
  11
  12 #include <common.h>
  13 #include <console.h>
  14 #include <dm.h>
  15 #include <fdtdec.h>
  16 #include <lcd.h>
  17 #include <os.h>
  18 #include <serial.h>
  19 #include <video.h>
  20 #include <linux/compiler.h>
  21 #include <asm/state.h>
  22
  23 DECLARE_GLOBAL_DATA_PTR;
  24
  25 /*
  26  *
  27  *   serial_buf: A buffer that holds keyboard characters for the
  28  *               Sandbox U-Boot.
  29  *
  30  * invariants:
  31  *   serial_buf_write            == serial_buf_read -> empty buffer
  32  *   (serial_buf_write + 1) % 16 == serial_buf_read -> full buffer
  33  */
  34 static char serial_buf[16];
  35 static unsigned int serial_buf_write;
  36 static unsigned int serial_buf_read;
  37
  38 struct sandbox_serial_platdata {
  39         int colour;     /* Text colour to use for output, -1 for none */
  40 };
  41
  42 struct sandbox_serial_priv {
  43         bool start_of_line;
  44 };
  45
  46 /**
  47  * output_ansi_colour() - Output an ANSI colour code
  48  *
  49  * @colour: Colour to output (0-7)
  50  */
  51 static void output_ansi_colour(int colour)
  52 {
  53         char ansi_code[] = "\x1b[1;3Xm";
  54
  55         ansi_code[5] = '0' + colour;
  56         os_write(1, ansi_code, sizeof(ansi_code) - 1);
  57 }
  58
  59 static void output_ansi_reset(void)
  60 {
  61         os_write(1, "\x1b[0m", 4);
  62 }
  63
  64 static int sandbox_serial_probe(struct udevice *dev)
  65 {
  66         struct sandbox_state *state = state_get_current();
  67         struct sandbox_serial_priv *priv = dev_get_priv(dev);
  68
  69         if (state->term_raw != STATE_TERM_COOKED)
  70                 os_tty_raw(0, state->term_raw == STATE_TERM_RAW_WITH_SIGS);
  71         priv->start_of_line = 0;
  72
  73         if (state->term_raw != STATE_TERM_RAW)
  74                 disable_ctrlc(1);
  75
  76         return 0;
  77 }
  78
  79 static int sandbox_serial_remove(struct udevice *dev)
  80 {
  81         struct sandbox_serial_platdata *plat = dev->platdata;
  82
  83         if (plat->colour != -1)
  84                 output_ansi_reset();
  85
  86         return 0;
  87 }
  88
  89 static int sandbox_serial_putc(struct udevice *dev, const char ch)
  90 {
  91         struct sandbox_serial_priv *priv = dev_get_priv(dev);
  92         struct sandbox_serial_platdata *plat = dev->platdata;
  93
  94         if (priv->start_of_line && plat->colour != -1) {
  95                 priv->start_of_line = false;
  96                 output_ansi_colour(plat->colour);
  97         }
  98
  99         os_write(1, &ch, 1);
 100         if (ch == '\n')
 101                 priv->start_of_line = true;
 102
 103         return 0;
 104 }
 105
 106 static unsigned int increment_buffer_index(unsigned int index)
 107 {
 108         return (index + 1) % ARRAY_SIZE(serial_buf);
 109 }
 110
 111 static int sandbox_serial_pending(struct udevice *dev, bool input)
 112 {
 113         const unsigned int next_index =
 114                 increment_buffer_index(serial_buf_write);
 115         ssize_t count;
 116
 117         if (!input)
 118                 return 0;
 119
 120         os_usleep(100);
 121 #ifndef CONFIG_SPL_BUILD
 122         video_sync_all();
 123 #endif
 124         if (next_index == serial_buf_read)
 125                 return 1;       /* buffer full */
 126
 127         count = os_read_no_block(0, &serial_buf[serial_buf_write], 1);
 128         if (count == 1)
 129                 serial_buf_write = next_index;
 130
 131         return serial_buf_write != serial_buf_read;
 132 }
 133
 134 static int sandbox_serial_getc(struct udevice *dev)
 135 {
 136         int result;
 137
 138         if (!sandbox_serial_pending(dev, true))
 139                 return -EAGAIN; /* buffer empty */
 140
 141         result = serial_buf[serial_buf_read];
 142         serial_buf_read = increment_buffer_index(serial_buf_read);
 143         return result;
 144 }
 145
 146 static const char * const ansi_colour[] = {
 147         "black", "red", "green", "yellow", "blue", "megenta", "cyan",
 148         "white",
 149 };
 150
 151 static int sandbox_serial_ofdata_to_platdata(struct udevice *dev)
 152 {
 153         struct sandbox_serial_platdata *plat = dev->platdata;
 154         const char *colour;
 155         int i;
 156
 157         plat->colour = -1;
 158         colour = fdt_getprop(gd->fdt_blob, dev_of_offset(dev),
 159                              "sandbox,text-colour", NULL);
 160         if (colour) {
 161                 for (i = 0; i < ARRAY_SIZE(ansi_colour); i++) {
 162                         if (!strcmp(colour, ansi_colour[i])) {
 163                                 plat->colour = i;
 164                                 break;
 165                         }
 166                 }
 167         }
 168
 169         return 0;
 170 }
 171
 172 static const struct dm_serial_ops sandbox_serial_ops = {
 173         .putc = sandbox_serial_putc,
 174         .pending = sandbox_serial_pending,
 175         .getc = sandbox_serial_getc,
 176 };
 177
 178 static const struct udevice_id sandbox_serial_ids[] = {
 179         { .compatible = "sandbox,serial" },
 180         { }
 181 };
 182
 183 U_BOOT_DRIVER(serial_sandbox) = {
 184         .name   = "serial_sandbox",
 185         .id     = UCLASS_SERIAL,
 186         .of_match = sandbox_serial_ids,
 187         .ofdata_to_platdata = sandbox_serial_ofdata_to_platdata,
 188         .platdata_auto_alloc_size = sizeof(struct sandbox_serial_platdata),
 189         .priv_auto_alloc_size = sizeof(struct sandbox_serial_priv),
 190         .probe = sandbox_serial_probe,
 191         .remove = sandbox_serial_remove,
 192         .ops    = &sandbox_serial_ops,
 193         .flags = DM_FLAG_PRE_RELOC,
 194 };
 195
 196 static const struct sandbox_serial_platdata platdata_non_fdt = {
 197         .colour = -1,
 198 };
 199
 200 U_BOOT_DEVICE(serial_sandbox_non_fdt) = {
 201         .name = "serial_sandbox",
 202         .platdata = &platdata_non_fdt,
 203 };