summaryrefslogtreecommitdiffstats
path: root/drivers/video/backlight/l4f00242t03.c
blob: 923eae2f85f8fbcf6b542c16d9e1f673642274e2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
/*
 * l4f00242t03.c -- support for Epson L4F00242T03 LCD
 *
 * Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved.
 *
 * Copyright (c) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
 *	Inspired by Marek Vasut work in l4f00242t03.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/lcd.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>

#include <linux/spi/spi.h>
#include <linux/spi/l4f00242t03.h>

struct l4f00242t03_priv {
	struct spi_device	*spi;
	struct lcd_device	*ld;
	int lcd_state;
	struct regulator *io_reg;
	struct regulator *core_reg;
};

static void l4f00242t03_reset(unsigned int gpio)
{
	pr_debug("l4f00242t03_reset.\n");
	gpio_set_value(gpio, 1);
	mdelay(100);
	gpio_set_value(gpio, 0);
	mdelay(10);	/* tRES >= 100us */
	gpio_set_value(gpio, 1);
	mdelay(20);
}

#define param(x) ((x) | 0x100)

static void l4f00242t03_lcd_init(struct spi_device *spi)
{
	struct l4f00242t03_pdata *pdata = dev_get_platdata(&spi->dev);
	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
	const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
	int ret;

	dev_dbg(&spi->dev, "initializing LCD\n");

	ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
	if (ret) {
		dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
		return;
	}
	ret = regulator_enable(priv->io_reg);
	if (ret) {
		dev_err(&spi->dev, "failed to enable the IO regulator.\n");
		return;
	}

	ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
	if (ret) {
		dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
		regulator_disable(priv->io_reg);
		return;
	}
	ret = regulator_enable(priv->core_reg);
	if (ret) {
		dev_err(&spi->dev, "failed to enable the core regulator.\n");
		regulator_disable(priv->io_reg);
		return;
	}

	l4f00242t03_reset(pdata->reset_gpio);

	gpio_set_value(pdata->data_enable_gpio, 1);
	msleep(60);
	spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
}

static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
{
	struct l4f00242t03_pdata *pdata = dev_get_platdata(&spi->dev);
	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);

	dev_dbg(&spi->dev, "Powering down LCD\n");

	gpio_set_value(pdata->data_enable_gpio, 0);

	regulator_disable(priv->io_reg);
	regulator_disable(priv->core_reg);
}

static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
{
	struct l4f00242t03_priv *priv = lcd_get_data(ld);

	return priv->lcd_state;
}

static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
{
	struct l4f00242t03_priv *priv = lcd_get_data(ld);
	struct spi_device *spi = priv->spi;

	const u16 slpout = 0x11;
	const u16 dison = 0x29;

	const u16 slpin = 0x10;
	const u16 disoff = 0x28;

	if (power <= FB_BLANK_NORMAL) {
		if (priv->lcd_state <= FB_BLANK_NORMAL) {
			/* Do nothing, the LCD is running */
		} else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
			dev_dbg(&spi->dev, "Resuming LCD\n");

			spi_write(spi, (const u8 *)&slpout, sizeof(u16));
			msleep(60);
			spi_write(spi, (const u8 *)&dison, sizeof(u16));
		} else {
			/* priv->lcd_state == FB_BLANK_POWERDOWN */
			l4f00242t03_lcd_init(spi);
			priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
			l4f00242t03_lcd_power_set(priv->ld, power);
		}
	} else if (power < FB_BLANK_POWERDOWN) {
		if (priv->lcd_state <= FB_BLANK_NORMAL) {
			/* Send the display in standby */
			dev_dbg(&spi->dev, "Standby the LCD\n");

			spi_write(spi, (const u8 *)&disoff, sizeof(u16));
			msleep(60);
			spi_write(spi, (const u8 *)&slpin, sizeof(u16));
		} else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
			/* Do nothing, the LCD is already in standby */
		} else {
			/* priv->lcd_state == FB_BLANK_POWERDOWN */
			l4f00242t03_lcd_init(spi);
			priv->lcd_state = FB_BLANK_UNBLANK;
			l4f00242t03_lcd_power_set(ld, power);
		}
	} else {
		/* power == FB_BLANK_POWERDOWN */
		if (priv->lcd_state != FB_BLANK_POWERDOWN) {
			/* Clear the screen before shutting down */
			spi_write(spi, (const u8 *)&disoff, sizeof(u16));
			msleep(60);
			l4f00242t03_lcd_powerdown(spi);
		}
	}

	priv->lcd_state = power;

	return 0;
}

static struct lcd_ops l4f_ops = {
	.set_power	= l4f00242t03_lcd_power_set,
	.get_power	= l4f00242t03_lcd_power_get,
};

static int l4f00242t03_probe(struct spi_device *spi)
{
	struct l4f00242t03_priv *priv;
	struct l4f00242t03_pdata *pdata = dev_get_platdata(&spi->dev);
	int ret;

	if (pdata == NULL) {
		dev_err(&spi->dev, "Uninitialized platform data.\n");
		return -EINVAL;
	}

	priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
				GFP_KERNEL);

	if (priv == NULL) {
		dev_err(&spi->dev, "No memory for this device.\n");
		return -ENOMEM;
	}

	spi_set_drvdata(spi, priv);
	spi->bits_per_word = 9;
	spi_setup(spi);

	priv->spi = spi;

	ret = devm_gpio_request_one(&spi->dev, pdata->reset_gpio,
			GPIOF_OUT_INIT_HIGH, "lcd l4f00242t03 reset");
	if (ret) {
		dev_err(&spi->dev,
			"Unable to get the lcd l4f00242t03 reset gpio.\n");
		return ret;
	}

	ret = devm_gpio_request_one(&spi->dev, pdata->data_enable_gpio,
			GPIOF_OUT_INIT_LOW, "lcd l4f00242t03 data enable");
	if (ret) {
		dev_err(&spi->dev,
			"Unable to get the lcd l4f00242t03 data en gpio.\n");
		return ret;
	}

	priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
	if (IS_ERR(priv->io_reg)) {
		dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
		       __func__);
		return PTR_ERR(priv->io_reg);
	}

	priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
	if (IS_ERR(priv->core_reg)) {
		dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
		       __func__);
		return PTR_ERR(priv->core_reg);
	}

	priv->ld = lcd_device_register("l4f00242t03",
					&spi->dev, priv, &l4f_ops);
	if (IS_ERR(priv->ld))
		return PTR_ERR(priv->ld);

	/* Init the LCD */
	l4f00242t03_lcd_init(spi);
	priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
	l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);

	dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");

	return 0;
}

static int l4f00242t03_remove(struct spi_device *spi)
{
	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);

	l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
	lcd_device_unregister(priv->ld);
	spi_set_drvdata(spi, NULL);

	return 0;
}

static void l4f00242t03_shutdown(struct spi_device *spi)
{
	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);

	if (priv)
		l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);

}

static struct spi_driver l4f00242t03_driver = {
	.driver = {
		.name	= "l4f00242t03",
		.owner	= THIS_MODULE,
	},
	.probe		= l4f00242t03_probe,
	.remove		= l4f00242t03_remove,
	.shutdown	= l4f00242t03_shutdown,
};

module_spi_driver(l4f00242t03_driver);

MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
MODULE_LICENSE("GPL v2");
OpenPOWER on IntegriCloud