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/module.h>
  18 #include <linux/gpio.h>
  19 #include <linux/lcd.h>
  20 #include <linux/slab.h>
  21 #include <linux/regulator/consumer.h>
  22
  23 #include <linux/spi/spi.h>
  24 #include <linux/spi/l4f00242t03.h>
  25
  26 struct l4f00242t03_priv {
  27         struct spi_device       *spi;
  28         struct lcd_device       *ld;
  29         int lcd_state;
  30         struct regulator *io_reg;
  31         struct regulator *core_reg;
  32 };
  33
  34
  35 static void l4f00242t03_reset(unsigned int gpio)
  36 {
  37         pr_debug("l4f00242t03_reset.\n");
  38         gpio_set_value(gpio, 1);
  39         mdelay(100);
  40         gpio_set_value(gpio, 0);
  41         mdelay(10);     /* tRES >= 100us */
  42         gpio_set_value(gpio, 1);
  43         mdelay(20);
  44 }
  45
  46 #define param(x) ((x) | 0x100)
  47
  48 static void l4f00242t03_lcd_init(struct spi_device *spi)
  49 {
  50         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
  51         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
  52         const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
  53
  54         dev_dbg(&spi->dev, "initializing LCD\n");
  55
  56         regulator_set_voltage(priv->io_reg, 1800000, 1800000);
  57         regulator_enable(priv->io_reg);
  58
  59         regulator_set_voltage(priv->core_reg, 2800000, 2800000);
  60         regulator_enable(priv->core_reg);
  61
  62         l4f00242t03_reset(pdata->reset_gpio);
  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 void l4f00242t03_lcd_powerdown(struct spi_device *spi)
  70 {
  71         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
  72         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
  73
  74         dev_dbg(&spi->dev, "Powering down LCD\n");
  75
  76         gpio_set_value(pdata->data_enable_gpio, 0);
  77
  78         regulator_disable(priv->io_reg);
  79         regulator_disable(priv->core_reg);
  80 }
  81
  82 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
  83 {
  84         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  85
  86         return priv->lcd_state;
  87 }
  88
  89 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
  90 {
  91         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  92         struct spi_device *spi = priv->spi;
  93
  94         const u16 slpout = 0x11;
  95         const u16 dison = 0x29;
  96
  97         const u16 slpin = 0x10;
  98         const u16 disoff = 0x28;
  99
 100         if (power <= FB_BLANK_NORMAL) {
 101                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 102                         /* Do nothing, the LCD is running */
 103                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 104                         dev_dbg(&spi->dev, "Resuming LCD\n");
 105
 106                         spi_write(spi, (const u8 *)&slpout, sizeof(u16));
 107                         msleep(60);
 108                         spi_write(spi, (const u8 *)&dison, sizeof(u16));
 109                 } else {
 110                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 111                         l4f00242t03_lcd_init(spi);
 112                         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 113                         l4f00242t03_lcd_power_set(priv->ld, power);
 114                 }
 115         } else if (power < FB_BLANK_POWERDOWN) {
 116                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 117                         /* Send the display in standby */
 118                         dev_dbg(&spi->dev, "Standby the LCD\n");
 119
 120                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 121                         msleep(60);
 122                         spi_write(spi, (const u8 *)&slpin, sizeof(u16));
 123                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 124                         /* Do nothing, the LCD is already in standby */
 125                 } else {
 126                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 127                         l4f00242t03_lcd_init(spi);
 128                         priv->lcd_state = FB_BLANK_UNBLANK;
 129                         l4f00242t03_lcd_power_set(ld, power);
 130                 }
 131         } else {
 132                 /* power == FB_BLANK_POWERDOWN */
 133                 if (priv->lcd_state != FB_BLANK_POWERDOWN) {
 134                         /* Clear the screen before shutting down */
 135                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 136                         msleep(60);
 137                         l4f00242t03_lcd_powerdown(spi);
 138                 }
 139         }
 140
 141         priv->lcd_state = power;
 142
 143         return 0;
 144 }
 145
 146 static struct lcd_ops l4f_ops = {
 147         .set_power      = l4f00242t03_lcd_power_set,
 148         .get_power      = l4f00242t03_lcd_power_get,
 149 };
 150
 151 static int __devinit l4f00242t03_probe(struct spi_device *spi)
 152 {
 153         struct l4f00242t03_priv *priv;
 154         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
 155         int ret;
 156
 157         if (pdata == NULL) {
 158                 dev_err(&spi->dev, "Uninitialized platform data.\n");
 159                 return -EINVAL;
 160         }
 161
 162         priv = kzalloc(sizeof(struct l4f00242t03_priv), GFP_KERNEL);
 163
 164         if (priv == NULL) {
 165                 dev_err(&spi->dev, "No memory for this device.\n");
 166                 return -ENOMEM;
 167         }
 168
 169         dev_set_drvdata(&spi->dev, priv);
 170         spi->bits_per_word = 9;
 171         spi_setup(spi);
 172
 173         priv->spi = spi;
 174
 175         ret = gpio_request_one(pdata->reset_gpio, GPIOF_OUT_INIT_HIGH,
 176                                                 "lcd l4f00242t03 reset");
 177         if (ret) {
 178                 dev_err(&spi->dev,
 179                         "Unable to get the lcd l4f00242t03 reset gpio.\n");
 180                 goto err;
 181         }
 182
 183         ret = gpio_request_one(pdata->data_enable_gpio, GPIOF_OUT_INIT_LOW,
 184                                                 "lcd l4f00242t03 data enable");
 185         if (ret) {
 186                 dev_err(&spi->dev,
 187                         "Unable to get the lcd l4f00242t03 data en gpio.\n");
 188                 goto err2;
 189         }
 190
 191         priv->io_reg = regulator_get(&spi->dev, "vdd");
 192         if (IS_ERR(priv->io_reg)) {
 193                 dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
 194                        __func__);
 195                 goto err3;
 196         }
 197
 198         priv->core_reg = regulator_get(&spi->dev, "vcore");
 199         if (IS_ERR(priv->core_reg)) {
 200                 dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
 201                        __func__);
 202                 goto err4;
 203         }
 204
 205         priv->ld = lcd_device_register("l4f00242t03",
 206                                         &spi->dev, priv, &l4f_ops);
 207         if (IS_ERR(priv->ld)) {
 208                 ret = PTR_ERR(priv->ld);
 209                 goto err5;
 210         }
 211
 212         /* Init the LCD */
 213         l4f00242t03_lcd_init(spi);
 214         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 215         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
 216
 217         dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
 218
 219         return 0;
 220
 221 err5:
 222         regulator_put(priv->core_reg);
 223 err4:
 224         regulator_put(priv->io_reg);
 225 err3:
 226         gpio_free(pdata->data_enable_gpio);
 227 err2:
 228         gpio_free(pdata->reset_gpio);
 229 err:
 230         kfree(priv);
 231
 232         return ret;
 233 }
 234
 235 static int __devexit l4f00242t03_remove(struct spi_device *spi)
 236 {
 237         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 238         struct l4f00242t03_pdata *pdata = priv->spi->dev.platform_data;
 239
 240         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 241         lcd_device_unregister(priv->ld);
 242
 243         dev_set_drvdata(&spi->dev, NULL);
 244
 245         gpio_free(pdata->data_enable_gpio);
 246         gpio_free(pdata->reset_gpio);
 247
 248         regulator_put(priv->io_reg);
 249         regulator_put(priv->core_reg);
 250
 251         kfree(priv);
 252
 253         return 0;
 254 }
 255
 256 static void l4f00242t03_shutdown(struct spi_device *spi)
 257 {
 258         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 259
 260         if (priv)
 261                 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 262
 263 }
 264
 265 static struct spi_driver l4f00242t03_driver = {
 266         .driver = {
 267                 .name   = "l4f00242t03",
 268                 .owner  = THIS_MODULE,
 269         },
 270         .probe          = l4f00242t03_probe,
 271         .remove         = __devexit_p(l4f00242t03_remove),
 272         .shutdown       = l4f00242t03_shutdown,
 273 };
 274
 275 static __init int l4f00242t03_init(void)
 276 {
 277         return spi_register_driver(&l4f00242t03_driver);
 278 }
 279
 280 static __exit void l4f00242t03_exit(void)
 281 {
 282         spi_unregister_driver(&l4f00242t03_driver);
 283 }
 284
 285 module_init(l4f00242t03_init);
 286 module_exit(l4f00242t03_exit);
 287
 288 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
 289 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
 290 MODULE_LICENSE("GPL v2");