1 /*
2 * l4f00242t03.c -- support for Epson L4F00242T03 LCD
3 *
4 * Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved.
5 *
6 * Copyright (c) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
7 * Inspired by Marek Vasut work in l4f00242t03.c
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/device.h>
17 #include <linux/kernel.h>
18 #include <linux/delay.h>
19 #include <linux/module.h>
20 #include <linux/gpio.h>
21 #include <linux/lcd.h>
22 #include <linux/slab.h>
23 #include <linux/regulator/consumer.h>
24
25 #include <linux/spi/spi.h>
26 #include <linux/spi/l4f00242t03.h>
27
28 struct l4f00242t03_priv {
29 struct spi_device *spi;
30 struct lcd_device *ld;
31 int lcd_state;
32 struct regulator *io_reg;
33 struct regulator *core_reg;
34 };
35
l4f00242t03_reset(unsigned int gpio)36 static void l4f00242t03_reset(unsigned int gpio)
37 {
38 pr_debug("l4f00242t03_reset.\n");
39 gpio_set_value(gpio, 1);
40 mdelay(100);
41 gpio_set_value(gpio, 0);
42 mdelay(10); /* tRES >= 100us */
43 gpio_set_value(gpio, 1);
44 mdelay(20);
45 }
46
47 #define param(x) ((x) | 0x100)
48
l4f00242t03_lcd_init(struct spi_device * spi)49 static void l4f00242t03_lcd_init(struct spi_device *spi)
50 {
51 struct l4f00242t03_pdata *pdata = dev_get_platdata(&spi->dev);
52 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
53 const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
54 int ret;
55
56 dev_dbg(&spi->dev, "initializing LCD\n");
57
58 ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
59 if (ret) {
60 dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
61 return;
62 }
63 ret = regulator_enable(priv->io_reg);
64 if (ret) {
65 dev_err(&spi->dev, "failed to enable the IO regulator.\n");
66 return;
67 }
68
69 ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
70 if (ret) {
71 dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
72 regulator_disable(priv->io_reg);
73 return;
74 }
75 ret = regulator_enable(priv->core_reg);
76 if (ret) {
77 dev_err(&spi->dev, "failed to enable the core regulator.\n");
78 regulator_disable(priv->io_reg);
79 return;
80 }
81
82 l4f00242t03_reset(pdata->reset_gpio);
83
84 gpio_set_value(pdata->data_enable_gpio, 1);
85 msleep(60);
86 spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
87 }
88
l4f00242t03_lcd_powerdown(struct spi_device * spi)89 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
90 {
91 struct l4f00242t03_pdata *pdata = dev_get_platdata(&spi->dev);
92 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
93
94 dev_dbg(&spi->dev, "Powering down LCD\n");
95
96 gpio_set_value(pdata->data_enable_gpio, 0);
97
98 regulator_disable(priv->io_reg);
99 regulator_disable(priv->core_reg);
100 }
101
l4f00242t03_lcd_power_get(struct lcd_device * ld)102 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
103 {
104 struct l4f00242t03_priv *priv = lcd_get_data(ld);
105
106 return priv->lcd_state;
107 }
108
l4f00242t03_lcd_power_set(struct lcd_device * ld,int power)109 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
110 {
111 struct l4f00242t03_priv *priv = lcd_get_data(ld);
112 struct spi_device *spi = priv->spi;
113
114 const u16 slpout = 0x11;
115 const u16 dison = 0x29;
116
117 const u16 slpin = 0x10;
118 const u16 disoff = 0x28;
119
120 if (power <= FB_BLANK_NORMAL) {
121 if (priv->lcd_state <= FB_BLANK_NORMAL) {
122 /* Do nothing, the LCD is running */
123 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
124 dev_dbg(&spi->dev, "Resuming LCD\n");
125
126 spi_write(spi, (const u8 *)&slpout, sizeof(u16));
127 msleep(60);
128 spi_write(spi, (const u8 *)&dison, sizeof(u16));
129 } else {
130 /* priv->lcd_state == FB_BLANK_POWERDOWN */
131 l4f00242t03_lcd_init(spi);
132 priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
133 l4f00242t03_lcd_power_set(priv->ld, power);
134 }
135 } else if (power < FB_BLANK_POWERDOWN) {
136 if (priv->lcd_state <= FB_BLANK_NORMAL) {
137 /* Send the display in standby */
138 dev_dbg(&spi->dev, "Standby the LCD\n");
139
140 spi_write(spi, (const u8 *)&disoff, sizeof(u16));
141 msleep(60);
142 spi_write(spi, (const u8 *)&slpin, sizeof(u16));
143 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
144 /* Do nothing, the LCD is already in standby */
145 } else {
146 /* priv->lcd_state == FB_BLANK_POWERDOWN */
147 l4f00242t03_lcd_init(spi);
148 priv->lcd_state = FB_BLANK_UNBLANK;
149 l4f00242t03_lcd_power_set(ld, power);
150 }
151 } else {
152 /* power == FB_BLANK_POWERDOWN */
153 if (priv->lcd_state != FB_BLANK_POWERDOWN) {
154 /* Clear the screen before shutting down */
155 spi_write(spi, (const u8 *)&disoff, sizeof(u16));
156 msleep(60);
157 l4f00242t03_lcd_powerdown(spi);
158 }
159 }
160
161 priv->lcd_state = power;
162
163 return 0;
164 }
165
166 static struct lcd_ops l4f_ops = {
167 .set_power = l4f00242t03_lcd_power_set,
168 .get_power = l4f00242t03_lcd_power_get,
169 };
170
l4f00242t03_probe(struct spi_device * spi)171 static int l4f00242t03_probe(struct spi_device *spi)
172 {
173 struct l4f00242t03_priv *priv;
174 struct l4f00242t03_pdata *pdata = dev_get_platdata(&spi->dev);
175 int ret;
176
177 if (pdata == NULL) {
178 dev_err(&spi->dev, "Uninitialized platform data.\n");
179 return -EINVAL;
180 }
181
182 priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
183 GFP_KERNEL);
184 if (priv == NULL)
185 return -ENOMEM;
186
187 spi_set_drvdata(spi, priv);
188 spi->bits_per_word = 9;
189 spi_setup(spi);
190
191 priv->spi = spi;
192
193 ret = devm_gpio_request_one(&spi->dev, pdata->reset_gpio,
194 GPIOF_OUT_INIT_HIGH, "lcd l4f00242t03 reset");
195 if (ret) {
196 dev_err(&spi->dev,
197 "Unable to get the lcd l4f00242t03 reset gpio.\n");
198 return ret;
199 }
200
201 ret = devm_gpio_request_one(&spi->dev, pdata->data_enable_gpio,
202 GPIOF_OUT_INIT_LOW, "lcd l4f00242t03 data enable");
203 if (ret) {
204 dev_err(&spi->dev,
205 "Unable to get the lcd l4f00242t03 data en gpio.\n");
206 return ret;
207 }
208
209 priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
210 if (IS_ERR(priv->io_reg)) {
211 dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
212 __func__);
213 return PTR_ERR(priv->io_reg);
214 }
215
216 priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
217 if (IS_ERR(priv->core_reg)) {
218 dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
219 __func__);
220 return PTR_ERR(priv->core_reg);
221 }
222
223 priv->ld = devm_lcd_device_register(&spi->dev, "l4f00242t03", &spi->dev,
224 priv, &l4f_ops);
225 if (IS_ERR(priv->ld))
226 return PTR_ERR(priv->ld);
227
228 /* Init the LCD */
229 l4f00242t03_lcd_init(spi);
230 priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
231 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
232
233 dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
234
235 return 0;
236 }
237
l4f00242t03_remove(struct spi_device * spi)238 static int l4f00242t03_remove(struct spi_device *spi)
239 {
240 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
241
242 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
243 return 0;
244 }
245
l4f00242t03_shutdown(struct spi_device * spi)246 static void l4f00242t03_shutdown(struct spi_device *spi)
247 {
248 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
249
250 if (priv)
251 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
252
253 }
254
255 static struct spi_driver l4f00242t03_driver = {
256 .driver = {
257 .name = "l4f00242t03",
258 },
259 .probe = l4f00242t03_probe,
260 .remove = l4f00242t03_remove,
261 .shutdown = l4f00242t03_shutdown,
262 };
263
264 module_spi_driver(l4f00242t03_driver);
265
266 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
267 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
268 MODULE_LICENSE("GPL v2");
269
