drivers/video/backlight/ltv350qv.c

   1 /*
   2  * Power control for Samsung LTV350QV Quarter VGA LCD Panel
   3  *
   4  * Copyright (C) 2006, 2007 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/delay.h>
  11 #include <linux/err.h>
  12 #include <linux/fb.h>
  13 #include <linux/init.h>
  14 #include <linux/lcd.h>
  15 #include <linux/module.h>
  16 #include <linux/spi/spi.h>
  17
  18 #include "ltv350qv.h"
  19
  20 #define POWER_IS_ON(pwr)        ((pwr) <= FB_BLANK_NORMAL)
  21
  22 struct ltv350qv {
  23         struct spi_device       *spi;
  24         u8                      *buffer;
  25         int                     power;
  26         struct lcd_device       *ld;
  27 };
  28
  29 /*
  30  * The power-on and power-off sequences are taken from the
  31  * LTV350QV-F04 data sheet from Samsung. The register definitions are
  32  * taken from the S6F2002 command list also from Samsung. Both
  33  * documents are distributed with the AVR32 Linux BSP CD from Atmel.
  34  *
  35  * There's still some voodoo going on here, but it's a lot better than
  36  * in the first incarnation of the driver where all we had was the raw
  37  * numbers from the initialization sequence.
  38  */
  39 static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)
  40 {
  41         struct spi_message msg;
  42         struct spi_transfer index_xfer = {
  43                 .len            = 3,
  44                 .cs_change      = 1,
  45         };
  46         struct spi_transfer value_xfer = {
  47                 .len            = 3,
  48         };
  49
  50         spi_message_init(&msg);
  51
  52         /* register index */
  53         lcd->buffer[0] = LTV_OPC_INDEX;
  54         lcd->buffer[1] = 0x00;
  55         lcd->buffer[2] = reg & 0x7f;
  56         index_xfer.tx_buf = lcd->buffer;
  57         spi_message_add_tail(&index_xfer, &msg);
  58
  59         /* register value */
  60         lcd->buffer[4] = LTV_OPC_DATA;
  61         lcd->buffer[5] = val >> 8;
  62         lcd->buffer[6] = val;
  63         value_xfer.tx_buf = lcd->buffer + 4;
  64         spi_message_add_tail(&value_xfer, &msg);
  65
  66         return spi_sync(lcd->spi, &msg);
  67 }
  68
  69 /* The comments are taken straight from the data sheet */
  70 static int ltv350qv_power_on(struct ltv350qv *lcd)
  71 {
  72         int ret;
  73
  74         /* Power On Reset Display off State */
  75         if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))
  76                 goto err;
  77         msleep(15);
  78
  79         /* Power Setting Function 1 */
  80         if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))
  81                 goto err;
  82         if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))
  83                 goto err_power1;
  84
  85         /* Power Setting Function 2 */
  86         if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,
  87                                LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
  88                                | LTV_SUPPLY_CURRENT(5)))
  89                 goto err_power2;
  90
  91         msleep(55);
  92
  93         /* Instruction Setting */
  94         ret = ltv350qv_write_reg(lcd, LTV_IFCTL,
  95                                  LTV_NMD | LTV_REV | LTV_NL(0x1d));
  96         ret |= ltv350qv_write_reg(lcd, LTV_DATACTL,
  97                                   LTV_DS_SAME | LTV_CHS_480
  98                                   | LTV_DF_RGB | LTV_RGB_BGR);
  99         ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,
 100                                   LTV_VSPL_ACTIVE_LOW
 101                                   | LTV_HSPL_ACTIVE_LOW
 102                                   | LTV_DPL_SAMPLE_RISING
 103                                   | LTV_EPL_ACTIVE_LOW
 104                                   | LTV_SS_RIGHT_TO_LEFT);
 105         ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));
 106         ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
 107                                   LTV_NW_INV_1LINE | LTV_FWI(3));
 108         ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);
 109         ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);
 110         ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0));
 111         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);
 112         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);
 113         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);
 114         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);
 115         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);
 116         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);
 117         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);
 118         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);
 119         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);
 120         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);
 121         if (ret)
 122                 goto err_settings;
 123
 124         /* Wait more than 2 frames */
 125         msleep(20);
 126
 127         /* Display On Sequence */
 128         ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 129                                  LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE
 130                                  | LTV_POWER_ON | LTV_DRIVE_CURRENT(5)
 131                                  | LTV_SUPPLY_CURRENT(5));
 132         ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
 133                                   LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3));
 134         if (ret)
 135                 goto err_disp_on;
 136
 137         /* Display should now be ON. Phew. */
 138         return 0;
 139
 140 err_disp_on:
 141         /*
 142          * Try to recover. Error handling probably isn't very useful
 143          * at this point, just make a best effort to switch the panel
 144          * off.
 145          */
 146         ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 147                            LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
 148                            | LTV_SUPPLY_CURRENT(5));
 149         ltv350qv_write_reg(lcd, LTV_GATECTL2,
 150                            LTV_NW_INV_1LINE | LTV_FWI(3));
 151 err_settings:
 152 err_power2:
 153 err_power1:
 154         ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
 155         msleep(1);
 156 err:
 157         ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
 158         return -EIO;
 159 }
 160
 161 static int ltv350qv_power_off(struct ltv350qv *lcd)
 162 {
 163         int ret;
 164
 165         /* Display Off Sequence */
 166         ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 167                                  LTV_VCOM_DISABLE
 168                                  | LTV_DRIVE_CURRENT(5)
 169                                  | LTV_SUPPLY_CURRENT(5));
 170         ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
 171                                   LTV_NW_INV_1LINE | LTV_FWI(3));
 172
 173         /* Power down setting 1 */
 174         ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
 175
 176         /* Wait at least 1 ms */
 177         msleep(1);
 178
 179         /* Power down setting 2 */
 180         ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
 181
 182         /*
 183          * No point in trying to recover here. If we can't switch the
 184          * panel off, what are we supposed to do other than inform the
 185          * user about the failure?
 186          */
 187         if (ret)
 188                 return -EIO;
 189
 190         /* Display power should now be OFF */
 191         return 0;
 192 }
 193
 194 static int ltv350qv_power(struct ltv350qv *lcd, int power)
 195 {
 196         int ret = 0;
 197
 198         if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
 199                 ret = ltv350qv_power_on(lcd);
 200         else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
 201                 ret = ltv350qv_power_off(lcd);
 202
 203         if (!ret)
 204                 lcd->power = power;
 205
 206         return ret;
 207 }
 208
 209 static int ltv350qv_set_power(struct lcd_device *ld, int power)
 210 {
 211         struct ltv350qv *lcd = lcd_get_data(ld);
 212
 213         return ltv350qv_power(lcd, power);
 214 }
 215
 216 static int ltv350qv_get_power(struct lcd_device *ld)
 217 {
 218         struct ltv350qv *lcd = lcd_get_data(ld);
 219
 220         return lcd->power;
 221 }
 222
 223 static struct lcd_ops ltv_ops = {
 224         .get_power      = ltv350qv_get_power,
 225         .set_power      = ltv350qv_set_power,
 226 };
 227
 228 static int __devinit ltv350qv_probe(struct spi_device *spi)
 229 {
 230         struct ltv350qv *lcd;
 231         struct lcd_device *ld;
 232         int ret;
 233
 234         lcd = kzalloc(sizeof(struct ltv350qv), GFP_KERNEL);
 235         if (!lcd)
 236                 return -ENOMEM;
 237
 238         lcd->spi = spi;
 239         lcd->power = FB_BLANK_POWERDOWN;
 240         lcd->buffer = kzalloc(8, GFP_KERNEL);
 241
 242         ld = lcd_device_register("ltv350qv", &spi->dev, lcd, &ltv_ops);
 243         if (IS_ERR(ld)) {
 244                 ret = PTR_ERR(ld);
 245                 goto out_free_lcd;
 246         }
 247         lcd->ld = ld;
 248
 249         ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
 250         if (ret)
 251                 goto out_unregister;
 252
 253         dev_set_drvdata(&spi->dev, lcd);
 254
 255         return 0;
 256
 257 out_unregister:
 258         lcd_device_unregister(ld);
 259 out_free_lcd:
 260         kfree(lcd);
 261         return ret;
 262 }
 263
 264 static int __devexit ltv350qv_remove(struct spi_device *spi)
 265 {
 266         struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
 267
 268         ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
 269         lcd_device_unregister(lcd->ld);
 270         kfree(lcd);
 271
 272         return 0;
 273 }
 274
 275 #ifdef CONFIG_PM
 276 static int ltv350qv_suspend(struct spi_device *spi, pm_message_t state)
 277 {
 278         struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
 279
 280         return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
 281 }
 282
 283 static int ltv350qv_resume(struct spi_device *spi)
 284 {
 285         struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
 286
 287         return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
 288 }
 289 #else
 290 #define ltv350qv_suspend        NULL
 291 #define ltv350qv_resume         NULL
 292 #endif
 293
 294 /* Power down all displays on reboot, poweroff or halt */
 295 static void ltv350qv_shutdown(struct spi_device *spi)
 296 {
 297         struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
 298
 299         ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
 300 }
 301
 302 static struct spi_driver ltv350qv_driver = {
 303         .driver = {
 304                 .name           = "ltv350qv",
 305                 .bus            = &spi_bus_type,
 306                 .owner          = THIS_MODULE,
 307         },
 308
 309         .probe          = ltv350qv_probe,
 310         .remove         = __devexit_p(ltv350qv_remove),
 311         .shutdown       = ltv350qv_shutdown,
 312         .suspend        = ltv350qv_suspend,
 313         .resume         = ltv350qv_resume,
 314 };
 315
 316 static int __init ltv350qv_init(void)
 317 {
 318         return spi_register_driver(&ltv350qv_driver);
 319 }
 320
 321 static void __exit ltv350qv_exit(void)
 322 {
 323         spi_unregister_driver(&ltv350qv_driver);
 324 }
 325 module_init(ltv350qv_init);
 326 module_exit(ltv350qv_exit);
 327
 328 MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
 329 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
 330 MODULE_LICENSE("GPL");
 331 MODULE_ALIAS("spi:ltv350qv");