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         if (priv->io_reg) {
  57                 regulator_set_voltage(priv->io_reg, 1800000, 1800000);
  58                 regulator_enable(priv->io_reg);
  59         }
  60
  61         if (priv->core_reg) {
  62                 regulator_set_voltage(priv->core_reg, 2800000, 2800000);
  63                 regulator_enable(priv->core_reg);
  64         }
  65
  66         l4f00242t03_reset(pdata->reset_gpio);
  67
  68         gpio_set_value(pdata->data_enable_gpio, 1);
  69         msleep(60);
  70         spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
  71 }
  72
  73 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
  74 {
  75         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
  76         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
  77
  78         dev_dbg(&spi->dev, "Powering down LCD\n");
  79
  80         gpio_set_value(pdata->data_enable_gpio, 0);
  81
  82         if (priv->io_reg)
  83                 regulator_disable(priv->io_reg);
  84
  85         if (priv->core_reg)
  86                 regulator_disable(priv->core_reg);
  87 }
  88
  89 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
  90 {
  91         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  92
  93         return priv->lcd_state;
  94 }
  95
  96 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
  97 {
  98         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  99         struct spi_device *spi = priv->spi;
 100
 101         const u16 slpout = 0x11;
 102         const u16 dison = 0x29;
 103
 104         const u16 slpin = 0x10;
 105         const u16 disoff = 0x28;
 106
 107         if (power <= FB_BLANK_NORMAL) {
 108                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 109                         /* Do nothing, the LCD is running */
 110                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 111                         dev_dbg(&spi->dev, "Resuming LCD\n");
 112
 113                         spi_write(spi, (const u8 *)&slpout, sizeof(u16));
 114                         msleep(60);
 115                         spi_write(spi, (const u8 *)&dison, sizeof(u16));
 116                 } else {
 117                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 118                         l4f00242t03_lcd_init(spi);
 119                         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 120                         l4f00242t03_lcd_power_set(priv->ld, power);
 121                 }
 122         } else if (power < FB_BLANK_POWERDOWN) {
 123                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 124                         /* Send the display in standby */
 125                         dev_dbg(&spi->dev, "Standby the LCD\n");
 126
 127                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 128                         msleep(60);
 129                         spi_write(spi, (const u8 *)&slpin, sizeof(u16));
 130                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 131                         /* Do nothing, the LCD is already in standby */
 132                 } else {
 133                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 134                         l4f00242t03_lcd_init(spi);
 135                         priv->lcd_state = FB_BLANK_UNBLANK;
 136                         l4f00242t03_lcd_power_set(ld, power);
 137                 }
 138         } else {
 139                 /* power == FB_BLANK_POWERDOWN */
 140                 if (priv->lcd_state != FB_BLANK_POWERDOWN) {
 141                         /* Clear the screen before shutting down */
 142                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 143                         msleep(60);
 144                         l4f00242t03_lcd_powerdown(spi);
 145                 }
 146         }
 147
 148         priv->lcd_state = power;
 149
 150         return 0;
 151 }
 152
 153 static struct lcd_ops l4f_ops = {
 154         .set_power      = l4f00242t03_lcd_power_set,
 155         .get_power      = l4f00242t03_lcd_power_get,
 156 };
 157
 158 static int __devinit l4f00242t03_probe(struct spi_device *spi)
 159 {
 160         struct l4f00242t03_priv *priv;
 161         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
 162         int ret;
 163
 164         if (pdata == NULL) {
 165                 dev_err(&spi->dev, "Uninitialized platform data.\n");
 166                 return -EINVAL;
 167         }
 168
 169         priv = kzalloc(sizeof(struct l4f00242t03_priv), GFP_KERNEL);
 170
 171         if (priv == NULL) {
 172                 dev_err(&spi->dev, "No memory for this device.\n");
 173                 return -ENOMEM;
 174         }
 175
 176         dev_set_drvdata(&spi->dev, priv);
 177         spi->bits_per_word = 9;
 178         spi_setup(spi);
 179
 180         priv->spi = spi;
 181
 182         ret = gpio_request(pdata->reset_gpio, "lcd l4f00242t03 reset");
 183         if (ret) {
 184                 dev_err(&spi->dev,
 185                         "Unable to get the lcd l4f00242t03 reset gpio.\n");
 186                 goto err;
 187         }
 188
 189         ret = gpio_direction_output(pdata->reset_gpio, 1);
 190         if (ret)
 191                 goto err2;
 192
 193         ret = gpio_request(pdata->data_enable_gpio,
 194                                 "lcd l4f00242t03 data enable");
 195         if (ret) {
 196                 dev_err(&spi->dev,
 197                         "Unable to get the lcd l4f00242t03 data en gpio.\n");
 198                 goto err2;
 199         }
 200
 201         ret = gpio_direction_output(pdata->data_enable_gpio, 0);
 202         if (ret)
 203                 goto err3;
 204
 205         if (pdata->io_supply) {
 206                 priv->io_reg = regulator_get(NULL, pdata->io_supply);
 207
 208                 if (IS_ERR(priv->io_reg)) {
 209                         pr_err("%s: Unable to get the IO regulator\n",
 210                                                                 __func__);
 211                         goto err3;
 212                 }
 213         }
 214
 215         if (pdata->core_supply) {
 216                 priv->core_reg = regulator_get(NULL, pdata->core_supply);
 217
 218                 if (IS_ERR(priv->core_reg)) {
 219                         pr_err("%s: Unable to get the core regulator\n",
 220                                                                 __func__);
 221                         goto err4;
 222                 }
 223         }
 224
 225         priv->ld = lcd_device_register("l4f00242t03",
 226                                         &spi->dev, priv, &l4f_ops);
 227         if (IS_ERR(priv->ld)) {
 228                 ret = PTR_ERR(priv->ld);
 229                 goto err5;
 230         }
 231
 232         /* Init the LCD */
 233         l4f00242t03_lcd_init(spi);
 234         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 235         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
 236
 237         dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
 238
 239         return 0;
 240
 241 err5:
 242         if (priv->core_reg)
 243                 regulator_put(priv->core_reg);
 244 err4:
 245         if (priv->io_reg)
 246                 regulator_put(priv->io_reg);
 247 err3:
 248         gpio_free(pdata->data_enable_gpio);
 249 err2:
 250         gpio_free(pdata->reset_gpio);
 251 err:
 252         kfree(priv);
 253
 254         return ret;
 255 }
 256
 257 static int __devexit l4f00242t03_remove(struct spi_device *spi)
 258 {
 259         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 260         struct l4f00242t03_pdata *pdata = priv->spi->dev.platform_data;
 261
 262         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 263         lcd_device_unregister(priv->ld);
 264
 265         dev_set_drvdata(&spi->dev, NULL);
 266
 267         gpio_free(pdata->data_enable_gpio);
 268         gpio_free(pdata->reset_gpio);
 269
 270         if (priv->io_reg)
 271                 regulator_put(priv->io_reg);
 272         if (priv->core_reg)
 273                 regulator_put(priv->core_reg);
 274
 275         kfree(priv);
 276
 277         return 0;
 278 }
 279
 280 static void l4f00242t03_shutdown(struct spi_device *spi)
 281 {
 282         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 283
 284         if (priv)
 285                 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 286
 287 }
 288
 289 static struct spi_driver l4f00242t03_driver = {
 290         .driver = {
 291                 .name   = "l4f00242t03",
 292                 .owner  = THIS_MODULE,
 293         },
 294         .probe          = l4f00242t03_probe,
 295         .remove         = __devexit_p(l4f00242t03_remove),
 296         .shutdown       = l4f00242t03_shutdown,
 297 };
 298
 299 static __init int l4f00242t03_init(void)
 300 {
 301         return spi_register_driver(&l4f00242t03_driver);
 302 }
 303
 304 static __exit void l4f00242t03_exit(void)
 305 {
 306         spi_unregister_driver(&l4f00242t03_driver);
 307 }
 308
 309 module_init(l4f00242t03_init);
 310 module_exit(l4f00242t03_exit);
 311
 312 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
 313 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
 314 MODULE_LICENSE("GPL v2");