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 #include <linux/device.h>
  15 #include <linux/kernel.h>
  16 #include <linux/delay.h>
  17 #include <linux/gpio.h>
  18 #include <linux/lcd.h>
  19 #include <linux/regulator/consumer.h>
  20
  21 #include <linux/spi/spi.h>
  22 #include <linux/spi/l4f00242t03.h>
  23
  24 struct l4f00242t03_priv {
  25         struct spi_device       *spi;
  26         struct lcd_device       *ld;
  27         int lcd_on:1;
  28         struct regulator *io_reg;
  29         struct regulator *core_reg;
  30 };
  31
  32
  33 static void l4f00242t03_reset(unsigned int gpio)
  34 {
  35         pr_debug("l4f00242t03_reset.\n");
  36         gpio_set_value(gpio, 1);
  37         mdelay(100);
  38         gpio_set_value(gpio, 0);
  39         mdelay(10);     /* tRES >= 100us */
  40         gpio_set_value(gpio, 1);
  41         mdelay(20);
  42 }
  43
  44 #define param(x) ((x) | 0x100)
  45
  46 static void l4f00242t03_lcd_init(struct spi_device *spi)
  47 {
  48         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
  49         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
  50         const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
  51
  52         dev_dbg(&spi->dev, "initializing LCD\n");
  53
  54         if (priv->io_reg) {
  55                 regulator_set_voltage(priv->io_reg, 1800000, 1800000);
  56                 regulator_enable(priv->io_reg);
  57         }
  58
  59         if (priv->core_reg) {
  60                 regulator_set_voltage(priv->core_reg, 2800000, 2800000);
  61                 regulator_enable(priv->core_reg);
  62         }
  63
  64         gpio_set_value(pdata->data_enable_gpio, 1);
  65         msleep(60);
  66         spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
  67 }
  68
  69 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
  70 {
  71         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  72         struct spi_device *spi = priv->spi;
  73
  74         const u16 slpout = 0x11;
  75         const u16 dison = 0x29;
  76
  77         const u16 slpin = 0x10;
  78         const u16 disoff = 0x28;
  79
  80         if (power) {
  81                 if (priv->lcd_on)
  82                         return 0;
  83
  84                 dev_dbg(&spi->dev, "turning on LCD\n");
  85
  86                 spi_write(spi, (const u8 *)&slpout, sizeof(u16));
  87                 msleep(60);
  88                 spi_write(spi, (const u8 *)&dison, sizeof(u16));
  89
  90                 priv->lcd_on = 1;
  91         } else {
  92                 if (!priv->lcd_on)
  93                         return 0;
  94
  95                 dev_dbg(&spi->dev, "turning off LCD\n");
  96
  97                 spi_write(spi, (const u8 *)&disoff, sizeof(u16));
  98                 msleep(60);
  99                 spi_write(spi, (const u8 *)&slpin, sizeof(u16));
 100
 101                 priv->lcd_on = 0;
 102         }
 103
 104         return 0;
 105 }
 106
 107 static struct lcd_ops l4f_ops = {
 108         .set_power      = l4f00242t03_lcd_power_set,
 109         .get_power      = NULL,
 110 };
 111
 112 static int __devinit l4f00242t03_probe(struct spi_device *spi)
 113 {
 114         struct l4f00242t03_priv *priv;
 115         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
 116         int ret;
 117
 118         if (pdata == NULL) {
 119                 dev_err(&spi->dev, "Uninitialized platform data.\n");
 120                 return -EINVAL;
 121         }
 122
 123         priv = kzalloc(sizeof(struct l4f00242t03_priv), GFP_KERNEL);
 124
 125         if (priv == NULL) {
 126                 dev_err(&spi->dev, "No memory for this device.\n");
 127                 ret = -ENOMEM;
 128                 goto err;
 129         }
 130
 131         dev_set_drvdata(&spi->dev, priv);
 132         spi->bits_per_word = 9;
 133         spi_setup(spi);
 134
 135         priv->spi = spi;
 136
 137         ret = gpio_request(pdata->reset_gpio, "lcd l4f00242t03 reset");
 138         if (ret) {
 139                 dev_err(&spi->dev,
 140                         "Unable to get the lcd l4f00242t03 reset gpio.\n");
 141                 return ret;
 142         }
 143
 144         ret = gpio_direction_output(pdata->reset_gpio, 1);
 145         if (ret)
 146                 goto err2;
 147
 148         ret = gpio_request(pdata->data_enable_gpio,
 149                                 "lcd l4f00242t03 data enable");
 150         if (ret) {
 151                 dev_err(&spi->dev,
 152                         "Unable to get the lcd l4f00242t03 data en gpio.\n");
 153                 return ret;
 154         }
 155
 156         ret = gpio_direction_output(pdata->data_enable_gpio, 0);
 157         if (ret)
 158                 goto err3;
 159
 160         if (pdata->io_supply) {
 161                 priv->io_reg = regulator_get(NULL, pdata->io_supply);
 162
 163                 if (IS_ERR(priv->io_reg)) {
 164                         pr_err("%s: Unable to get the IO regulator\n",
 165                                                                 __func__);
 166                         goto err3;
 167                 }
 168         }
 169
 170         if (pdata->core_supply) {
 171                 priv->core_reg = regulator_get(NULL, pdata->core_supply);
 172
 173                 if (IS_ERR(priv->core_reg)) {
 174                         pr_err("%s: Unable to get the core regulator\n",
 175                                                                 __func__);
 176                         goto err4;
 177                 }
 178         }
 179
 180         priv->ld = lcd_device_register("l4f00242t03",
 181                                         &spi->dev, priv, &l4f_ops);
 182         if (IS_ERR(priv->ld)) {
 183                 ret = PTR_ERR(priv->ld);
 184                 goto err5;
 185         }
 186
 187         /* Init the LCD */
 188         l4f00242t03_reset(pdata->reset_gpio);
 189         l4f00242t03_lcd_init(spi);
 190         l4f00242t03_lcd_power_set(priv->ld, 1);
 191
 192         dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
 193
 194         return 0;
 195
 196 err5:
 197         if (priv->core_reg)
 198                 regulator_put(priv->core_reg);
 199 err4:
 200         if (priv->io_reg)
 201                 regulator_put(priv->io_reg);
 202 err3:
 203         gpio_free(pdata->data_enable_gpio);
 204 err2:
 205         gpio_free(pdata->reset_gpio);
 206 err:
 207         kfree(priv);
 208
 209         return ret;
 210 }
 211
 212 static int __devexit l4f00242t03_remove(struct spi_device *spi)
 213 {
 214         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 215         struct l4f00242t03_pdata *pdata = priv->spi->dev.platform_data;
 216
 217         l4f00242t03_lcd_power_set(priv->ld, 0);
 218         lcd_device_unregister(priv->ld);
 219
 220         gpio_free(pdata->data_enable_gpio);
 221         gpio_free(pdata->reset_gpio);
 222
 223         if (priv->io_reg)
 224                 regulator_put(priv->core_reg);
 225         if (priv->core_reg)
 226                 regulator_put(priv->io_reg);
 227
 228         kfree(priv);
 229
 230         return 0;
 231 }
 232
 233 static struct spi_driver l4f00242t03_driver = {
 234         .driver = {
 235                 .name   = "l4f00242t03",
 236                 .owner  = THIS_MODULE,
 237         },
 238         .probe          = l4f00242t03_probe,
 239         .remove         = __devexit_p(l4f00242t03_remove),
 240 };
 241
 242 static __init int l4f00242t03_init(void)
 243 {
 244         return spi_register_driver(&l4f00242t03_driver);
 245 }
 246
 247 static __exit void l4f00242t03_exit(void)
 248 {
 249         spi_unregister_driver(&l4f00242t03_driver);
 250 }
 251
 252 module_init(l4f00242t03_init);
 253 module_exit(l4f00242t03_exit);
 254
 255 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
 256 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
 257 MODULE_LICENSE("GPL v2");