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_state;
  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         regulator_set_voltage(priv->io_reg, 1800000, 1800000);
  56         regulator_enable(priv->io_reg);
  57
  58         regulator_set_voltage(priv->core_reg, 2800000, 2800000);
  59         regulator_enable(priv->core_reg);
  60
  61         l4f00242t03_reset(pdata->reset_gpio);
  62
  63         gpio_set_value(pdata->data_enable_gpio, 1);
  64         msleep(60);
  65         spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
  66 }
  67
  68 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
  69 {
  70         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
  71         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
  72
  73         dev_dbg(&spi->dev, "Powering down LCD\n");
  74
  75         gpio_set_value(pdata->data_enable_gpio, 0);
  76
  77         regulator_disable(priv->io_reg);
  78         regulator_disable(priv->core_reg);
  79 }
  80
  81 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
  82 {
  83         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  84
  85         return priv->lcd_state;
  86 }
  87
  88 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
  89 {
  90         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  91         struct spi_device *spi = priv->spi;
  92
  93         const u16 slpout = 0x11;
  94         const u16 dison = 0x29;
  95
  96         const u16 slpin = 0x10;
  97         const u16 disoff = 0x28;
  98
  99         if (power <= FB_BLANK_NORMAL) {
 100                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 101                         /* Do nothing, the LCD is running */
 102                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 103                         dev_dbg(&spi->dev, "Resuming LCD\n");
 104
 105                         spi_write(spi, (const u8 *)&slpout, sizeof(u16));
 106                         msleep(60);
 107                         spi_write(spi, (const u8 *)&dison, sizeof(u16));
 108                 } else {
 109                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 110                         l4f00242t03_lcd_init(spi);
 111                         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 112                         l4f00242t03_lcd_power_set(priv->ld, power);
 113                 }
 114         } else if (power < FB_BLANK_POWERDOWN) {
 115                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 116                         /* Send the display in standby */
 117                         dev_dbg(&spi->dev, "Standby the LCD\n");
 118
 119                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 120                         msleep(60);
 121                         spi_write(spi, (const u8 *)&slpin, sizeof(u16));
 122                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 123                         /* Do nothing, the LCD is already in standby */
 124                 } else {
 125                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 126                         l4f00242t03_lcd_init(spi);
 127                         priv->lcd_state = FB_BLANK_UNBLANK;
 128                         l4f00242t03_lcd_power_set(ld, power);
 129                 }
 130         } else {
 131                 /* power == FB_BLANK_POWERDOWN */
 132                 if (priv->lcd_state != FB_BLANK_POWERDOWN) {
 133                         /* Clear the screen before shutting down */
 134                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 135                         msleep(60);
 136                         l4f00242t03_lcd_powerdown(spi);
 137                 }
 138         }
 139
 140         priv->lcd_state = power;
 141
 142         return 0;
 143 }
 144
 145 static struct lcd_ops l4f_ops = {
 146         .set_power      = l4f00242t03_lcd_power_set,
 147         .get_power      = l4f00242t03_lcd_power_get,
 148 };
 149
 150 static int __devinit l4f00242t03_probe(struct spi_device *spi)
 151 {
 152         struct l4f00242t03_priv *priv;
 153         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
 154         int ret;
 155
 156         if (pdata == NULL) {
 157                 dev_err(&spi->dev, "Uninitialized platform data.\n");
 158                 return -EINVAL;
 159         }
 160
 161         priv = kzalloc(sizeof(struct l4f00242t03_priv), GFP_KERNEL);
 162
 163         if (priv == NULL) {
 164                 dev_err(&spi->dev, "No memory for this device.\n");
 165                 return -ENOMEM;
 166         }
 167
 168         dev_set_drvdata(&spi->dev, priv);
 169         spi->bits_per_word = 9;
 170         spi_setup(spi);
 171
 172         priv->spi = spi;
 173
 174         ret = gpio_request_one(pdata->reset_gpio, GPIOF_OUT_INIT_HIGH,
 175                                                 "lcd l4f00242t03 reset");
 176         if (ret) {
 177                 dev_err(&spi->dev,
 178                         "Unable to get the lcd l4f00242t03 reset gpio.\n");
 179                 goto err;
 180         }
 181
 182         ret = gpio_request_one(pdata->data_enable_gpio, GPIOF_OUT_INIT_LOW,
 183                                                 "lcd l4f00242t03 data enable");
 184         if (ret) {
 185                 dev_err(&spi->dev,
 186                         "Unable to get the lcd l4f00242t03 data en gpio.\n");
 187                 goto err2;
 188         }
 189
 190         priv->io_reg = regulator_get(&spi->dev, "vdd");
 191         if (IS_ERR(priv->io_reg)) {
 192                 dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
 193                        __func__);
 194                 goto err3;
 195         }
 196
 197         priv->core_reg = regulator_get(&spi->dev, "vcore");
 198         if (IS_ERR(priv->core_reg)) {
 199                 dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
 200                        __func__);
 201                 goto err4;
 202         }
 203
 204         priv->ld = lcd_device_register("l4f00242t03",
 205                                         &spi->dev, priv, &l4f_ops);
 206         if (IS_ERR(priv->ld)) {
 207                 ret = PTR_ERR(priv->ld);
 208                 goto err5;
 209         }
 210
 211         /* Init the LCD */
 212         l4f00242t03_lcd_init(spi);
 213         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 214         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
 215
 216         dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
 217
 218         return 0;
 219
 220 err5:
 221         regulator_put(priv->core_reg);
 222 err4:
 223         regulator_put(priv->io_reg);
 224 err3:
 225         gpio_free(pdata->data_enable_gpio);
 226 err2:
 227         gpio_free(pdata->reset_gpio);
 228 err:
 229         kfree(priv);
 230
 231         return ret;
 232 }
 233
 234 static int __devexit l4f00242t03_remove(struct spi_device *spi)
 235 {
 236         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 237         struct l4f00242t03_pdata *pdata = priv->spi->dev.platform_data;
 238
 239         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 240         lcd_device_unregister(priv->ld);
 241
 242         dev_set_drvdata(&spi->dev, NULL);
 243
 244         gpio_free(pdata->data_enable_gpio);
 245         gpio_free(pdata->reset_gpio);
 246
 247         regulator_put(priv->io_reg);
 248         regulator_put(priv->core_reg);
 249
 250         kfree(priv);
 251
 252         return 0;
 253 }
 254
 255 static void l4f00242t03_shutdown(struct spi_device *spi)
 256 {
 257         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 258
 259         if (priv)
 260                 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 261
 262 }
 263
 264 static struct spi_driver l4f00242t03_driver = {
 265         .driver = {
 266                 .name   = "l4f00242t03",
 267                 .owner  = THIS_MODULE,
 268         },
 269         .probe          = l4f00242t03_probe,
 270         .remove         = __devexit_p(l4f00242t03_remove),
 271         .shutdown       = l4f00242t03_shutdown,
 272 };
 273
 274 static __init int l4f00242t03_init(void)
 275 {
 276         return spi_register_driver(&l4f00242t03_driver);
 277 }
 278
 279 static __exit void l4f00242t03_exit(void)
 280 {
 281         spi_unregister_driver(&l4f00242t03_driver);
 282 }
 283
 284 module_init(l4f00242t03_init);
 285 module_exit(l4f00242t03_exit);
 286
 287 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
 288 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
 289 MODULE_LICENSE("GPL v2");