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         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         if (priv->io_reg)
  80                 regulator_disable(priv->io_reg);
  81
  82         if (priv->core_reg)
  83                 regulator_disable(priv->core_reg);
  84 }
  85
  86 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
  87 {
  88         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  89
  90         return priv->lcd_state;
  91 }
  92
  93 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
  94 {
  95         struct l4f00242t03_priv *priv = lcd_get_data(ld);
  96         struct spi_device *spi = priv->spi;
  97
  98         const u16 slpout = 0x11;
  99         const u16 dison = 0x29;
 100
 101         const u16 slpin = 0x10;
 102         const u16 disoff = 0x28;
 103
 104         if (power <= FB_BLANK_NORMAL) {
 105                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 106                         /* Do nothing, the LCD is running */
 107                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 108                         dev_dbg(&spi->dev, "Resuming LCD\n");
 109
 110                         spi_write(spi, (const u8 *)&slpout, sizeof(u16));
 111                         msleep(60);
 112                         spi_write(spi, (const u8 *)&dison, sizeof(u16));
 113                 } else {
 114                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 115                         l4f00242t03_lcd_init(spi);
 116                         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 117                         l4f00242t03_lcd_power_set(priv->ld, power);
 118                 }
 119         } else if (power < FB_BLANK_POWERDOWN) {
 120                 if (priv->lcd_state <= FB_BLANK_NORMAL) {
 121                         /* Send the display in standby */
 122                         dev_dbg(&spi->dev, "Standby the LCD\n");
 123
 124                         spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 125                         msleep(60);
 126                         spi_write(spi, (const u8 *)&slpin, sizeof(u16));
 127                 } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 128                         /* Do nothing, the LCD is already in standby */
 129                 } else {
 130                         /* priv->lcd_state == FB_BLANK_POWERDOWN */
 131                         l4f00242t03_lcd_init(spi);
 132                         priv->lcd_state = FB_BLANK_UNBLANK;
 133                         l4f00242t03_lcd_power_set(ld, power);
 134                 }
 135         } else {
 136                 /* power == FB_BLANK_POWERDOWN */
 137                 /* Clear the screen before shutting down */
 138                 spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 139                 msleep(60);
 140                 l4f00242t03_lcd_powerdown(spi);
 141         }
 142
 143         priv->lcd_state = power;
 144
 145         return 0;
 146 }
 147
 148 static struct lcd_ops l4f_ops = {
 149         .set_power      = l4f00242t03_lcd_power_set,
 150         .get_power      = l4f00242t03_lcd_power_get,
 151 };
 152
 153 static int __devinit l4f00242t03_probe(struct spi_device *spi)
 154 {
 155         struct l4f00242t03_priv *priv;
 156         struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
 157         int ret;
 158
 159         if (pdata == NULL) {
 160                 dev_err(&spi->dev, "Uninitialized platform data.\n");
 161                 return -EINVAL;
 162         }
 163
 164         priv = kzalloc(sizeof(struct l4f00242t03_priv), 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 = gpio_request(pdata->reset_gpio, "lcd l4f00242t03 reset");
 178         if (ret) {
 179                 dev_err(&spi->dev,
 180                         "Unable to get the lcd l4f00242t03 reset gpio.\n");
 181                 goto err;
 182         }
 183
 184         ret = gpio_direction_output(pdata->reset_gpio, 1);
 185         if (ret)
 186                 goto err2;
 187
 188         ret = gpio_request(pdata->data_enable_gpio,
 189                                 "lcd l4f00242t03 data enable");
 190         if (ret) {
 191                 dev_err(&spi->dev,
 192                         "Unable to get the lcd l4f00242t03 data en gpio.\n");
 193                 goto err2;
 194         }
 195
 196         ret = gpio_direction_output(pdata->data_enable_gpio, 0);
 197         if (ret)
 198                 goto err3;
 199
 200         if (pdata->io_supply) {
 201                 priv->io_reg = regulator_get(NULL, pdata->io_supply);
 202
 203                 if (IS_ERR(priv->io_reg)) {
 204                         pr_err("%s: Unable to get the IO regulator\n",
 205                                                                 __func__);
 206                         goto err3;
 207                 }
 208         }
 209
 210         if (pdata->core_supply) {
 211                 priv->core_reg = regulator_get(NULL, pdata->core_supply);
 212
 213                 if (IS_ERR(priv->core_reg)) {
 214                         pr_err("%s: Unable to get the core regulator\n",
 215                                                                 __func__);
 216                         goto err4;
 217                 }
 218         }
 219
 220         priv->ld = lcd_device_register("l4f00242t03",
 221                                         &spi->dev, priv, &l4f_ops);
 222         if (IS_ERR(priv->ld)) {
 223                 ret = PTR_ERR(priv->ld);
 224                 goto err5;
 225         }
 226
 227         /* Init the LCD */
 228         l4f00242t03_reset(pdata->reset_gpio);
 229         l4f00242t03_lcd_init(spi);
 230         priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 231         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
 232
 233         dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
 234
 235         return 0;
 236
 237 err5:
 238         if (priv->core_reg)
 239                 regulator_put(priv->core_reg);
 240 err4:
 241         if (priv->io_reg)
 242                 regulator_put(priv->io_reg);
 243 err3:
 244         gpio_free(pdata->data_enable_gpio);
 245 err2:
 246         gpio_free(pdata->reset_gpio);
 247 err:
 248         kfree(priv);
 249
 250         return ret;
 251 }
 252
 253 static int __devexit l4f00242t03_remove(struct spi_device *spi)
 254 {
 255         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 256         struct l4f00242t03_pdata *pdata = priv->spi->dev.platform_data;
 257
 258         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 259         lcd_device_unregister(priv->ld);
 260
 261         dev_set_drvdata(&spi->dev, NULL);
 262
 263         gpio_free(pdata->data_enable_gpio);
 264         gpio_free(pdata->reset_gpio);
 265
 266         if (priv->io_reg)
 267                 regulator_put(priv->io_reg);
 268         if (priv->core_reg)
 269                 regulator_put(priv->core_reg);
 270
 271         kfree(priv);
 272
 273         return 0;
 274 }
 275
 276 static void l4f00242t03_shutdown(struct spi_device *spi)
 277 {
 278         struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
 279
 280         if (priv)
 281                 l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 282
 283 }
 284
 285 static struct spi_driver l4f00242t03_driver = {
 286         .driver = {
 287                 .name   = "l4f00242t03",
 288                 .owner  = THIS_MODULE,
 289         },
 290         .probe          = l4f00242t03_probe,
 291         .remove         = __devexit_p(l4f00242t03_remove),
 292         .shutdown       = l4f00242t03_shutdown,
 293 };
 294
 295 static __init int l4f00242t03_init(void)
 296 {
 297         return spi_register_driver(&l4f00242t03_driver);
 298 }
 299
 300 static __exit void l4f00242t03_exit(void)
 301 {
 302         spi_unregister_driver(&l4f00242t03_driver);
 303 }
 304
 305 module_init(l4f00242t03_init);
 306 module_exit(l4f00242t03_exit);
 307
 308 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
 309 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
 310 MODULE_LICENSE("GPL v2");