1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * l4f00242t03.c -- support for Epson L4F00242T03 LCD
4 *
5 * Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved.
6 *
7 * Copyright (c) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
8 * Inspired by Marek Vasut work in l4f00242t03.c
9 */
10
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13 #include <linux/device.h>
14 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/module.h>
17 #include <linux/gpio/consumer.h>
18 #include <linux/lcd.h>
19 #include <linux/slab.h>
20 #include <linux/regulator/consumer.h>
21 #include <linux/spi/spi.h>
22
23 struct l4f00242t03_priv {
24 struct spi_device *spi;
25 struct lcd_device *ld;
26 int lcd_state;
27 struct regulator *io_reg;
28 struct regulator *core_reg;
29 struct gpio_desc *reset;
30 struct gpio_desc *enable;
31 };
32
l4f00242t03_reset(struct gpio_desc * gpiod)33 static void l4f00242t03_reset(struct gpio_desc *gpiod)
34 {
35 pr_debug("l4f00242t03_reset.\n");
36 gpiod_set_value(gpiod, 1);
37 mdelay(100);
38 gpiod_set_value(gpiod, 0);
39 mdelay(10); /* tRES >= 100us */
40 gpiod_set_value(gpiod, 1);
41 mdelay(20);
42 }
43
44 #define param(x) ((x) | 0x100)
45
l4f00242t03_lcd_init(struct spi_device * spi)46 static void l4f00242t03_lcd_init(struct spi_device *spi)
47 {
48 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
49 const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
50 int ret;
51
52 dev_dbg(&spi->dev, "initializing LCD\n");
53
54 ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
55 if (ret) {
56 dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
57 return;
58 }
59 ret = regulator_enable(priv->io_reg);
60 if (ret) {
61 dev_err(&spi->dev, "failed to enable the IO regulator.\n");
62 return;
63 }
64
65 ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
66 if (ret) {
67 dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
68 regulator_disable(priv->io_reg);
69 return;
70 }
71 ret = regulator_enable(priv->core_reg);
72 if (ret) {
73 dev_err(&spi->dev, "failed to enable the core regulator.\n");
74 regulator_disable(priv->io_reg);
75 return;
76 }
77
78 l4f00242t03_reset(priv->reset);
79
80 gpiod_set_value(priv->enable, 1);
81 msleep(60);
82 spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
83 }
84
l4f00242t03_lcd_powerdown(struct spi_device * spi)85 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
86 {
87 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
88
89 dev_dbg(&spi->dev, "Powering down LCD\n");
90
91 gpiod_set_value(priv->enable, 0);
92
93 regulator_disable(priv->io_reg);
94 regulator_disable(priv->core_reg);
95 }
96
l4f00242t03_lcd_power_get(struct lcd_device * ld)97 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
98 {
99 struct l4f00242t03_priv *priv = lcd_get_data(ld);
100
101 return priv->lcd_state;
102 }
103
l4f00242t03_lcd_power_set(struct lcd_device * ld,int power)104 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
105 {
106 struct l4f00242t03_priv *priv = lcd_get_data(ld);
107 struct spi_device *spi = priv->spi;
108
109 const u16 slpout = 0x11;
110 const u16 dison = 0x29;
111
112 const u16 slpin = 0x10;
113 const u16 disoff = 0x28;
114
115 if (power <= FB_BLANK_NORMAL) {
116 if (priv->lcd_state <= FB_BLANK_NORMAL) {
117 /* Do nothing, the LCD is running */
118 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
119 dev_dbg(&spi->dev, "Resuming LCD\n");
120
121 spi_write(spi, (const u8 *)&slpout, sizeof(u16));
122 msleep(60);
123 spi_write(spi, (const u8 *)&dison, sizeof(u16));
124 } else {
125 /* priv->lcd_state == FB_BLANK_POWERDOWN */
126 l4f00242t03_lcd_init(spi);
127 priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
128 l4f00242t03_lcd_power_set(priv->ld, power);
129 }
130 } else if (power < FB_BLANK_POWERDOWN) {
131 if (priv->lcd_state <= FB_BLANK_NORMAL) {
132 /* Send the display in standby */
133 dev_dbg(&spi->dev, "Standby the LCD\n");
134
135 spi_write(spi, (const u8 *)&disoff, sizeof(u16));
136 msleep(60);
137 spi_write(spi, (const u8 *)&slpin, sizeof(u16));
138 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
139 /* Do nothing, the LCD is already in standby */
140 } else {
141 /* priv->lcd_state == FB_BLANK_POWERDOWN */
142 l4f00242t03_lcd_init(spi);
143 priv->lcd_state = FB_BLANK_UNBLANK;
144 l4f00242t03_lcd_power_set(ld, power);
145 }
146 } else {
147 /* power == FB_BLANK_POWERDOWN */
148 if (priv->lcd_state != FB_BLANK_POWERDOWN) {
149 /* Clear the screen before shutting down */
150 spi_write(spi, (const u8 *)&disoff, sizeof(u16));
151 msleep(60);
152 l4f00242t03_lcd_powerdown(spi);
153 }
154 }
155
156 priv->lcd_state = power;
157
158 return 0;
159 }
160
161 static struct lcd_ops l4f_ops = {
162 .set_power = l4f00242t03_lcd_power_set,
163 .get_power = l4f00242t03_lcd_power_get,
164 };
165
l4f00242t03_probe(struct spi_device * spi)166 static int l4f00242t03_probe(struct spi_device *spi)
167 {
168 struct l4f00242t03_priv *priv;
169
170 priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
171 GFP_KERNEL);
172 if (priv == NULL)
173 return -ENOMEM;
174
175 spi_set_drvdata(spi, priv);
176 spi->bits_per_word = 9;
177 spi_setup(spi);
178
179 priv->spi = spi;
180
181 priv->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
182 if (IS_ERR(priv->reset)) {
183 dev_err(&spi->dev,
184 "Unable to get the lcd l4f00242t03 reset gpio.\n");
185 return PTR_ERR(priv->reset);
186 }
187 gpiod_set_consumer_name(priv->reset, "lcd l4f00242t03 reset");
188
189 priv->enable = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
190 if (IS_ERR(priv->enable)) {
191 dev_err(&spi->dev,
192 "Unable to get the lcd l4f00242t03 data en gpio.\n");
193 return PTR_ERR(priv->enable);
194 }
195 gpiod_set_consumer_name(priv->enable, "lcd l4f00242t03 data enable");
196
197 priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
198 if (IS_ERR(priv->io_reg)) {
199 dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
200 __func__);
201 return PTR_ERR(priv->io_reg);
202 }
203
204 priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
205 if (IS_ERR(priv->core_reg)) {
206 dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
207 __func__);
208 return PTR_ERR(priv->core_reg);
209 }
210
211 priv->ld = devm_lcd_device_register(&spi->dev, "l4f00242t03", &spi->dev,
212 priv, &l4f_ops);
213 if (IS_ERR(priv->ld))
214 return PTR_ERR(priv->ld);
215
216 /* Init the LCD */
217 l4f00242t03_lcd_init(spi);
218 priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
219 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
220
221 dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
222
223 return 0;
224 }
225
l4f00242t03_remove(struct spi_device * spi)226 static void l4f00242t03_remove(struct spi_device *spi)
227 {
228 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
229
230 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
231 }
232
l4f00242t03_shutdown(struct spi_device * spi)233 static void l4f00242t03_shutdown(struct spi_device *spi)
234 {
235 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
236
237 if (priv)
238 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
239
240 }
241
242 static struct spi_driver l4f00242t03_driver = {
243 .driver = {
244 .name = "l4f00242t03",
245 },
246 .probe = l4f00242t03_probe,
247 .remove = l4f00242t03_remove,
248 .shutdown = l4f00242t03_shutdown,
249 };
250
251 module_spi_driver(l4f00242t03_driver);
252
253 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
254 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
255 MODULE_LICENSE("GPL v2");
256