xref: /openbmc/u-boot/drivers/serial/sandbox.c (revision fea7f3aa)
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 };
200