backlight: l4f00242t03: fix checkpatch warning
[~shefty/rdma-dev.git] / drivers / video / backlight / l4f00242t03.c
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
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
49 static void l4f00242t03_lcd_init(struct spi_device *spi)
50 {
51         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
52         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
53         const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
54
55         dev_dbg(&spi->dev, "initializing LCD\n");
56
57         regulator_set_voltage(priv->io_reg, 1800000, 1800000);
58         regulator_enable(priv->io_reg);
59
60         regulator_set_voltage(priv->core_reg, 2800000, 2800000);
61         regulator_enable(priv->core_reg);
62
63         l4f00242t03_reset(pdata->reset_gpio);
64
65         gpio_set_value(pdata->data_enable_gpio, 1);
66         msleep(60);
67         spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
68 }
69
70 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
71 {
72         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
73         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
74
75         dev_dbg(&spi->dev, "Powering down LCD\n");
76
77         gpio_set_value(pdata->data_enable_gpio, 0);
78
79         regulator_disable(priv->io_reg);
80         regulator_disable(priv->core_reg);
81 }
82
83 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
84 {
85         struct l4f00242t03_priv *priv = lcd_get_data(ld);
86
87         return priv->lcd_state;
88 }
89
90 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
91 {
92         struct l4f00242t03_priv *priv = lcd_get_data(ld);
93         struct spi_device *spi = priv->spi;
94
95         const u16 slpout = 0x11;
96         const u16 dison = 0x29;
97
98         const u16 slpin = 0x10;
99         const u16 disoff = 0x28;
100
101         if (power <= FB_BLANK_NORMAL) {
102                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
103                         /* Do nothing, the LCD is running */
104                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
105                         dev_dbg(&spi->dev, "Resuming LCD\n");
106
107                         spi_write(spi, (const u8 *)&slpout, sizeof(u16));
108                         msleep(60);
109                         spi_write(spi, (const u8 *)&dison, sizeof(u16));
110                 } else {
111                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
112                         l4f00242t03_lcd_init(spi);
113                         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
114                         l4f00242t03_lcd_power_set(priv->ld, power);
115                 }
116         } else if (power < FB_BLANK_POWERDOWN) {
117                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
118                         /* Send the display in standby */
119                         dev_dbg(&spi->dev, "Standby the LCD\n");
120
121                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
122                         msleep(60);
123                         spi_write(spi, (const u8 *)&slpin, sizeof(u16));
124                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
125                         /* Do nothing, the LCD is already in standby */
126                 } else {
127                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
128                         l4f00242t03_lcd_init(spi);
129                         priv->lcd_state = FB_BLANK_UNBLANK;
130                         l4f00242t03_lcd_power_set(ld, power);
131                 }
132         } else {
133                 /* power == FB_BLANK_POWERDOWN */
134                 if (priv->lcd_state != FB_BLANK_POWERDOWN) {
135                         /* Clear the screen before shutting down */
136                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
137                         msleep(60);
138                         l4f00242t03_lcd_powerdown(spi);
139                 }
140         }
141
142         priv->lcd_state = power;
143
144         return 0;
145 }
146
147 static struct lcd_ops l4f_ops = {
148         .set_power      = l4f00242t03_lcd_power_set,
149         .get_power      = l4f00242t03_lcd_power_get,
150 };
151
152 static int l4f00242t03_probe(struct spi_device *spi)
153 {
154         struct l4f00242t03_priv *priv;
155         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
156         int ret;
157
158         if (pdata == NULL) {
159                 dev_err(&spi->dev, "Uninitialized platform data.\n");
160                 return -EINVAL;
161         }
162
163         priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
164                                 GFP_KERNEL);
165
166         if (priv == NULL) {
167                 dev_err(&spi->dev, "No memory for this device.\n");
168                 return -ENOMEM;
169         }
170
171         dev_set_drvdata(&spi->dev, priv);
172         spi->bits_per_word = 9;
173         spi_setup(spi);
174
175         priv->spi = spi;
176
177         ret = devm_gpio_request_one(&spi->dev, pdata->reset_gpio,
178                         GPIOF_OUT_INIT_HIGH, "lcd l4f00242t03 reset");
179         if (ret) {
180                 dev_err(&spi->dev,
181                         "Unable to get the lcd l4f00242t03 reset gpio.\n");
182                 return ret;
183         }
184
185         ret = devm_gpio_request_one(&spi->dev, pdata->data_enable_gpio,
186                         GPIOF_OUT_INIT_LOW, "lcd l4f00242t03 data enable");
187         if (ret) {
188                 dev_err(&spi->dev,
189                         "Unable to get the lcd l4f00242t03 data en gpio.\n");
190                 return ret;
191         }
192
193         priv->io_reg = regulator_get(&spi->dev, "vdd");
194         if (IS_ERR(priv->io_reg)) {
195                 dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
196                        __func__);
197                 return PTR_ERR(priv->io_reg);
198         }
199
200         priv->core_reg = regulator_get(&spi->dev, "vcore");
201         if (IS_ERR(priv->core_reg)) {
202                 ret = PTR_ERR(priv->core_reg);
203                 dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
204                        __func__);
205                 goto err1;
206         }
207
208         priv->ld = lcd_device_register("l4f00242t03",
209                                         &spi->dev, priv, &l4f_ops);
210         if (IS_ERR(priv->ld)) {
211                 ret = PTR_ERR(priv->ld);
212                 goto err2;
213         }
214
215         /* Init the LCD */
216         l4f00242t03_lcd_init(spi);
217         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
218         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
219
220         dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
221
222         return 0;
223
224 err2:
225         regulator_put(priv->core_reg);
226 err1:
227         regulator_put(priv->io_reg);
228
229         return ret;
230 }
231
232 static int l4f00242t03_remove(struct spi_device *spi)
233 {
234         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
235
236         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
237         lcd_device_unregister(priv->ld);
238
239         dev_set_drvdata(&spi->dev, NULL);
240
241         regulator_put(priv->io_reg);
242         regulator_put(priv->core_reg);
243
244         return 0;
245 }
246
247 static void l4f00242t03_shutdown(struct spi_device *spi)
248 {
249         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
250
251         if (priv)
252                 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
253
254 }
255
256 static struct spi_driver l4f00242t03_driver = {
257         .driver = {
258                 .name   = "l4f00242t03",
259                 .owner  = THIS_MODULE,
260         },
261         .probe          = l4f00242t03_probe,
262         .remove         = l4f00242t03_remove,
263         .shutdown       = l4f00242t03_shutdown,
264 };
265
266 module_spi_driver(l4f00242t03_driver);
267
268 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
269 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
270 MODULE_LICENSE("GPL v2");