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
  37 static void l4f00242t03_reset(unsigned int gpio)
  38 {
  39         pr_debug("l4f00242t03_reset.\n");
  40         gpio_set_value(gpio, 1);
  41         mdelay(100);
  42         gpio_set_value(gpio, 0);
  43         mdelay(10);     /* tRES >= 100us */
  44         gpio_set_value(gpio, 1);
  45         mdelay(20);
  46 }
  47
  48 #define param(x) ((x) | 0x100)
  49
  50 static void l4f00242t03_lcd_init(struct spi_device *spi)
  51 {
  52         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
  53         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
  54         const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
  55
  56         dev_dbg(&spi->dev, "initializing LCD\n");
  57
  58         regulator_set_voltage(priv->io_reg, 1800000, 1800000);
  59         regulator_enable(priv->io_reg);
  60
  61         regulator_set_voltage(priv->core_reg, 2800000, 2800000);
  62         regulator_enable(priv->core_reg);
  63
  64         l4f00242t03_reset(pdata->reset_gpio);
  65
  66         gpio_set_value(pdata->data_enable_gpio, 1);
  67         msleep(60);
  68         spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
  69 }
  70
  71 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
  72 {
  73         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
  74         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
  75
  76         dev_dbg(&spi->dev, "Powering down LCD\n");
  77
  78         gpio_set_value(pdata->data_enable_gpio, 0);
  79
  80         regulator_disable(priv->io_reg);
  81         regulator_disable(priv->core_reg);
  82 }
  83
  84 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
  85 {
  86         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  87
  88         return priv->lcd_state;
  89 }
  90
  91 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
  92 {
  93         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  94         struct spi_device *spi = priv->spi;
  95
  96         const u16 slpout = 0x11;
  97         const u16 dison = 0x29;
  98
  99         const u16 slpin = 0x10;
 100         const u16 disoff = 0x28;
 101
 102         if (power <= FB_BLANK_NORMAL) {
 103                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 104                         /* Do nothing, the LCD is running */
 105                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 106                         dev_dbg(&spi->dev, "Resuming LCD\n");
 107
 108                         spi_write(spi, (const u8 *)&slpout, sizeof(u16));
 109                         msleep(60);
 110                         spi_write(spi, (const u8 *)&dison, sizeof(u16));
 111                 } else {
 112                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 113                         l4f00242t03_lcd_init(spi);
 114                         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 115                         l4f00242t03_lcd_power_set(priv->ld, power);
 116                 }
 117         } else if (power < FB_BLANK_POWERDOWN) {
 118                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 119                         /* Send the display in standby */
 120                         dev_dbg(&spi->dev, "Standby the LCD\n");
 121
 122                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 123                         msleep(60);
 124                         spi_write(spi, (const u8 *)&slpin, sizeof(u16));
 125                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 126                         /* Do nothing, the LCD is already in standby */
 127                 } else {
 128                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 129                         l4f00242t03_lcd_init(spi);
 130                         priv->lcd_state = FB_BLANK_UNBLANK;
 131                         l4f00242t03_lcd_power_set(ld, power);
 132                 }
 133         } else {
 134                 /* power == FB_BLANK_POWERDOWN */
 135                 if (priv->lcd_state != FB_BLANK_POWERDOWN) {
 136                         /* Clear the screen before shutting down */
 137                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 138                         msleep(60);
 139                         l4f00242t03_lcd_powerdown(spi);
 140                 }
 141         }
 142
 143         priv->lcd_state = power;
 144
 145         return 0;
 146 }
 147
 148 static struct lcd_ops l4f_ops = {
 149         .set_power      = l4f00242t03_lcd_power_set,
 150         .get_power      = l4f00242t03_lcd_power_get,
 151 };
 152
 153 static int __devinit l4f00242t03_probe(struct spi_device *spi)
 154 {
 155         struct l4f00242t03_priv *priv;
 156         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
 157         int ret;
 158
 159         if (pdata == NULL) {
 160                 dev_err(&spi->dev, "Uninitialized platform data.\n");
 161                 return -EINVAL;
 162         }
 163
 164         priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
 165                                 GFP_KERNEL);
 166
 167         if (priv == NULL) {
 168                 dev_err(&spi->dev, "No memory for this device.\n");
 169                 return -ENOMEM;
 170         }
 171
 172         dev_set_drvdata(&spi->dev, priv);
 173         spi->bits_per_word = 9;
 174         spi_setup(spi);
 175
 176         priv->spi = spi;
 177
 178         ret = devm_gpio_request_one(&spi->dev, pdata->reset_gpio,
 179                         GPIOF_OUT_INIT_HIGH, "lcd l4f00242t03 reset");
 180         if (ret) {
 181                 dev_err(&spi->dev,
 182                         "Unable to get the lcd l4f00242t03 reset gpio.\n");
 183                 return ret;
 184         }
 185
 186         ret = devm_gpio_request_one(&spi->dev, pdata->data_enable_gpio,
 187                         GPIOF_OUT_INIT_LOW, "lcd l4f00242t03 data enable");
 188         if (ret) {
 189                 dev_err(&spi->dev,
 190                         "Unable to get the lcd l4f00242t03 data en gpio.\n");
 191                 return ret;
 192         }
 193
 194         priv->io_reg = regulator_get(&spi->dev, "vdd");
 195         if (IS_ERR(priv->io_reg)) {
 196                 dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
 197                        __func__);
 198                 return PTR_ERR(priv->io_reg);
 199         }
 200
 201         priv->core_reg = regulator_get(&spi->dev, "vcore");
 202         if (IS_ERR(priv->core_reg)) {
 203                 ret = PTR_ERR(priv->core_reg);
 204                 dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
 205                        __func__);
 206                 goto err1;
 207         }
 208
 209         priv->ld = lcd_device_register("l4f00242t03",
 210                                         &spi->dev, priv, &l4f_ops);
 211         if (IS_ERR(priv->ld)) {
 212                 ret = PTR_ERR(priv->ld);
 213                 goto err2;
 214         }
 215
 216         /* Init the LCD */
 217         l4f00242t03_lcd_init(spi);
 218         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 219         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
 220
 221         dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
 222
 223         return 0;
 224
 225 err2:
 226         regulator_put(priv->core_reg);
 227 err1:
 228         regulator_put(priv->io_reg);
 229
 230         return ret;
 231 }
 232
 233 static int __devexit l4f00242t03_remove(struct spi_device *spi)
 234 {
 235         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 236
 237         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 238         lcd_device_unregister(priv->ld);
 239
 240         dev_set_drvdata(&spi->dev, NULL);
 241
 242         regulator_put(priv->io_reg);
 243         regulator_put(priv->core_reg);
 244
 245         return 0;
 246 }
 247
 248 static void l4f00242t03_shutdown(struct spi_device *spi)
 249 {
 250         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 251
 252         if (priv)
 253                 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 254
 255 }
 256
 257 static struct spi_driver l4f00242t03_driver = {
 258         .driver = {
 259                 .name   = "l4f00242t03",
 260                 .owner  = THIS_MODULE,
 261         },
 262         .probe          = l4f00242t03_probe,
 263         .remove         = __devexit_p(l4f00242t03_remove),
 264         .shutdown       = l4f00242t03_shutdown,
 265 };
 266
 267 module_spi_driver(l4f00242t03_driver);
 268
 269 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
 270 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
 271 MODULE_LICENSE("GPL v2");