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");