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