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