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 = spi_get_drvdata(spi);
  53         const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
  54         int ret;
  55
  56         dev_dbg(&spi->dev, "initializing LCD\n");
  57
  58         ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
  59         if (ret) {
  60                 dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
  61                 return;
  62         }
  63         ret = regulator_enable(priv->io_reg);
  64         if (ret) {
  65                 dev_err(&spi->dev, "failed to enable the IO regulator.\n");
  66                 return;
  67         }
  68
  69         ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
  70         if (ret) {
  71                 dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
  72                 regulator_disable(priv->io_reg);
  73                 return;
  74         }
  75         ret = regulator_enable(priv->core_reg);
  76         if (ret) {
  77                 dev_err(&spi->dev, "failed to enable the core regulator.\n");
  78                 regulator_disable(priv->io_reg);
  79                 return;
  80         }
  81
  82         l4f00242t03_reset(pdata->reset_gpio);
  83
  84         gpio_set_value(pdata->data_enable_gpio, 1);
  85         msleep(60);
  86         spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
  87 }
  88
  89 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
  90 {
  91         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
  92         struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
  93
  94         dev_dbg(&spi->dev, "Powering down LCD\n");
  95
  96         gpio_set_value(pdata->data_enable_gpio, 0);
  97
  98         regulator_disable(priv->io_reg);
  99         regulator_disable(priv->core_reg);
 100 }
 101
 102 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
 103 {
 104         struct l4f00242t03_priv *priv = lcd_get_data(ld);
 105
 106         return priv->lcd_state;
 107 }
 108
 109 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
 110 {
 111         struct l4f00242t03_priv *priv = lcd_get_data(ld);
 112         struct spi_device *spi = priv->spi;
 113
 114         const u16 slpout = 0x11;
 115         const u16 dison = 0x29;
 116
 117         const u16 slpin = 0x10;
 118         const u16 disoff = 0x28;
 119
 120         if (power <= FB_BLANK_NORMAL) {
 121                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 122                         /* Do nothing, the LCD is running */
 123                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 124                         dev_dbg(&spi->dev, "Resuming LCD\n");
 125
 126                         spi_write(spi, (const u8 *)&slpout, sizeof(u16));
 127                         msleep(60);
 128                         spi_write(spi, (const u8 *)&dison, sizeof(u16));
 129                 } else {
 130                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 131                         l4f00242t03_lcd_init(spi);
 132                         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 133                         l4f00242t03_lcd_power_set(priv->ld, power);
 134                 }
 135         } else if (power < FB_BLANK_POWERDOWN) {
 136                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 137                         /* Send the display in standby */
 138                         dev_dbg(&spi->dev, "Standby the LCD\n");
 139
 140                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 141                         msleep(60);
 142                         spi_write(spi, (const u8 *)&slpin, sizeof(u16));
 143                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 144                         /* Do nothing, the LCD is already in standby */
 145                 } else {
 146                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 147                         l4f00242t03_lcd_init(spi);
 148                         priv->lcd_state = FB_BLANK_UNBLANK;
 149                         l4f00242t03_lcd_power_set(ld, power);
 150                 }
 151         } else {
 152                 /* power == FB_BLANK_POWERDOWN */
 153                 if (priv->lcd_state != FB_BLANK_POWERDOWN) {
 154                         /* Clear the screen before shutting down */
 155                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 156                         msleep(60);
 157                         l4f00242t03_lcd_powerdown(spi);
 158                 }
 159         }
 160
 161         priv->lcd_state = power;
 162
 163         return 0;
 164 }
 165
 166 static struct lcd_ops l4f_ops = {
 167         .set_power      = l4f00242t03_lcd_power_set,
 168         .get_power      = l4f00242t03_lcd_power_get,
 169 };
 170
 171 static int l4f00242t03_probe(struct spi_device *spi)
 172 {
 173         struct l4f00242t03_priv *priv;
 174         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
 175         int ret;
 176
 177         if (pdata == NULL) {
 178                 dev_err(&spi->dev, "Uninitialized platform data.\n");
 179                 return -EINVAL;
 180         }
 181
 182         priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
 183                                 GFP_KERNEL);
 184
 185         if (priv == NULL) {
 186                 dev_err(&spi->dev, "No memory for this device.\n");
 187                 return -ENOMEM;
 188         }
 189
 190         spi_set_drvdata(spi, priv);
 191         spi->bits_per_word = 9;
 192         spi_setup(spi);
 193
 194         priv->spi = spi;
 195
 196         ret = devm_gpio_request_one(&spi->dev, pdata->reset_gpio,
 197                         GPIOF_OUT_INIT_HIGH, "lcd l4f00242t03 reset");
 198         if (ret) {
 199                 dev_err(&spi->dev,
 200                         "Unable to get the lcd l4f00242t03 reset gpio.\n");
 201                 return ret;
 202         }
 203
 204         ret = devm_gpio_request_one(&spi->dev, pdata->data_enable_gpio,
 205                         GPIOF_OUT_INIT_LOW, "lcd l4f00242t03 data enable");
 206         if (ret) {
 207                 dev_err(&spi->dev,
 208                         "Unable to get the lcd l4f00242t03 data en gpio.\n");
 209                 return ret;
 210         }
 211
 212         priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
 213         if (IS_ERR(priv->io_reg)) {
 214                 dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
 215                        __func__);
 216                 return PTR_ERR(priv->io_reg);
 217         }
 218
 219         priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
 220         if (IS_ERR(priv->core_reg)) {
 221                 dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
 222                        __func__);
 223                 return PTR_ERR(priv->core_reg);
 224         }
 225
 226         priv->ld = lcd_device_register("l4f00242t03",
 227                                         &spi->dev, priv, &l4f_ops);
 228         if (IS_ERR(priv->ld))
 229                 return PTR_ERR(priv->ld);
 230
 231         /* Init the LCD */
 232         l4f00242t03_lcd_init(spi);
 233         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 234         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
 235
 236         dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
 237
 238         return 0;
 239 }
 240
 241 static int l4f00242t03_remove(struct spi_device *spi)
 242 {
 243         struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
 244
 245         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 246         lcd_device_unregister(priv->ld);
 247         spi_set_drvdata(spi, NULL);
 248
 249         return 0;
 250 }
 251
 252 static void l4f00242t03_shutdown(struct spi_device *spi)
 253 {
 254         struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
 255
 256         if (priv)
 257                 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 258
 259 }
 260
 261 static struct spi_driver l4f00242t03_driver = {
 262         .driver = {
 263                 .name   = "l4f00242t03",
 264                 .owner  = THIS_MODULE,
 265         },
 266         .probe          = l4f00242t03_probe,
 267         .remove         = l4f00242t03_remove,
 268         .shutdown       = l4f00242t03_shutdown,
 269 };
 270
 271 module_spi_driver(l4f00242t03_driver);
 272
 273 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
 274 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
 275 MODULE_LICENSE("GPL v2");