xref: /openbmc/u-boot/drivers/serial/sandbox.c (revision 8729d582)
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 <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 	return 0;
74 }
75 
76 static int sandbox_serial_remove(struct udevice *dev)
77 {
78 	struct sandbox_serial_platdata *plat = dev->platdata;
79 
80 	if (plat->colour != -1)
81 		output_ansi_reset();
82 
83 	return 0;
84 }
85 
86 static int sandbox_serial_putc(struct udevice *dev, const char ch)
87 {
88 	struct sandbox_serial_priv *priv = dev_get_priv(dev);
89 	struct sandbox_serial_platdata *plat = dev->platdata;
90 
91 	if (priv->start_of_line && plat->colour != -1) {
92 		priv->start_of_line = false;
93 		output_ansi_colour(plat->colour);
94 	}
95 
96 	os_write(1, &ch, 1);
97 	if (ch == '\n')
98 		priv->start_of_line = true;
99 
100 	return 0;
101 }
102 
103 static unsigned int increment_buffer_index(unsigned int index)
104 {
105 	return (index + 1) % ARRAY_SIZE(serial_buf);
106 }
107 
108 static int sandbox_serial_pending(struct udevice *dev, bool input)
109 {
110 	const unsigned int next_index =
111 		increment_buffer_index(serial_buf_write);
112 	ssize_t count;
113 
114 	if (!input)
115 		return 0;
116 
117 	os_usleep(100);
118 	video_sync_all();
119 	if (next_index == serial_buf_read)
120 		return 1;	/* buffer full */
121 
122 	count = os_read_no_block(0, &serial_buf[serial_buf_write], 1);
123 	if (count == 1)
124 		serial_buf_write = next_index;
125 
126 	return serial_buf_write != serial_buf_read;
127 }
128 
129 static int sandbox_serial_getc(struct udevice *dev)
130 {
131 	int result;
132 
133 	if (!sandbox_serial_pending(dev, true))
134 		return -EAGAIN;	/* buffer empty */
135 
136 	result = serial_buf[serial_buf_read];
137 	serial_buf_read = increment_buffer_index(serial_buf_read);
138 	return result;
139 }
140 
141 static const char * const ansi_colour[] = {
142 	"black", "red", "green", "yellow", "blue", "megenta", "cyan",
143 	"white",
144 };
145 
146 static int sandbox_serial_ofdata_to_platdata(struct udevice *dev)
147 {
148 	struct sandbox_serial_platdata *plat = dev->platdata;
149 	const char *colour;
150 	int i;
151 
152 	plat->colour = -1;
153 	colour = fdt_getprop(gd->fdt_blob, dev->of_offset,
154 			     "sandbox,text-colour", NULL);
155 	if (colour) {
156 		for (i = 0; i < ARRAY_SIZE(ansi_colour); i++) {
157 			if (!strcmp(colour, ansi_colour[i])) {
158 				plat->colour = i;
159 				break;
160 			}
161 		}
162 	}
163 
164 	return 0;
165 }
166 
167 static const struct dm_serial_ops sandbox_serial_ops = {
168 	.putc = sandbox_serial_putc,
169 	.pending = sandbox_serial_pending,
170 	.getc = sandbox_serial_getc,
171 };
172 
173 static const struct udevice_id sandbox_serial_ids[] = {
174 	{ .compatible = "sandbox,serial" },
175 	{ }
176 };
177 
178 U_BOOT_DRIVER(serial_sandbox) = {
179 	.name	= "serial_sandbox",
180 	.id	= UCLASS_SERIAL,
181 	.of_match = sandbox_serial_ids,
182 	.ofdata_to_platdata = sandbox_serial_ofdata_to_platdata,
183 	.platdata_auto_alloc_size = sizeof(struct sandbox_serial_platdata),
184 	.priv_auto_alloc_size = sizeof(struct sandbox_serial_priv),
185 	.probe = sandbox_serial_probe,
186 	.remove = sandbox_serial_remove,
187 	.ops	= &sandbox_serial_ops,
188 	.flags = DM_FLAG_PRE_RELOC,
189 };
190 
191 static const struct sandbox_serial_platdata platdata_non_fdt = {
192 	.colour = -1,
193 };
194 
195 U_BOOT_DEVICE(serial_sandbox_non_fdt) = {
196 	.name = "serial_sandbox",
197 	.platdata = &platdata_non_fdt,
198 };
199