drivers/video/backlight/ltv350qv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Power control for Samsung LTV350QV Quarter VGA LCD Panel
   4  *
   5  * Copyright (C) 2006, 2007 Atmel Corporation
   6  */
   7 #include <linux/delay.h>
   8 #include <linux/err.h>
   9 #include <linux/fb.h>
  10 #include <linux/init.h>
  11 #include <linux/lcd.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/spi/spi.h>
  15
  16 #include "ltv350qv.h"
  17
  18 #define POWER_IS_ON(pwr)        ((pwr) <= FB_BLANK_NORMAL)
  19
  20 struct ltv350qv {
  21         struct spi_device       *spi;
  22         u8                      *buffer;
  23         int                     power;
  24         struct lcd_device       *ld;
  25 };
  26
  27 /*
  28  * The power-on and power-off sequences are taken from the
  29  * LTV350QV-F04 data sheet from Samsung. The register definitions are
  30  * taken from the S6F2002 command list also from Samsung. Both
  31  * documents are distributed with the AVR32 Linux BSP CD from Atmel.
  32  *
  33  * There's still some voodoo going on here, but it's a lot better than
  34  * in the first incarnation of the driver where all we had was the raw
  35  * numbers from the initialization sequence.
  36  */
  37 static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)
  38 {
  39         struct spi_message msg;
  40         struct spi_transfer index_xfer = {
  41                 .len            = 3,
  42                 .cs_change      = 1,
  43         };
  44         struct spi_transfer value_xfer = {
  45                 .len            = 3,
  46         };
  47
  48         spi_message_init(&msg);
  49
  50         /* register index */
  51         lcd->buffer[0] = LTV_OPC_INDEX;
  52         lcd->buffer[1] = 0x00;
  53         lcd->buffer[2] = reg & 0x7f;
  54         index_xfer.tx_buf = lcd->buffer;
  55         spi_message_add_tail(&index_xfer, &msg);
  56
  57         /* register value */
  58         lcd->buffer[4] = LTV_OPC_DATA;
  59         lcd->buffer[5] = val >> 8;
  60         lcd->buffer[6] = val;
  61         value_xfer.tx_buf = lcd->buffer + 4;
  62         spi_message_add_tail(&value_xfer, &msg);
  63
  64         return spi_sync(lcd->spi, &msg);
  65 }
  66
  67 /* The comments are taken straight from the data sheet */
  68 static int ltv350qv_power_on(struct ltv350qv *lcd)
  69 {
  70         int ret;
  71
  72         /* Power On Reset Display off State */
  73         if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))
  74                 goto err;
  75         usleep_range(15000, 16000);
  76
  77         /* Power Setting Function 1 */
  78         if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))
  79                 goto err;
  80         if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))
  81                 goto err_power1;
  82
  83         /* Power Setting Function 2 */
  84         if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,
  85                                LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
  86                                | LTV_SUPPLY_CURRENT(5)))
  87                 goto err_power2;
  88
  89         msleep(55);
  90
  91         /* Instruction Setting */
  92         ret = ltv350qv_write_reg(lcd, LTV_IFCTL,
  93                                  LTV_NMD | LTV_REV | LTV_NL(0x1d));
  94         ret |= ltv350qv_write_reg(lcd, LTV_DATACTL,
  95                                   LTV_DS_SAME | LTV_CHS_480
  96                                   | LTV_DF_RGB | LTV_RGB_BGR);
  97         ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,
  98                                   LTV_VSPL_ACTIVE_LOW
  99                                   | LTV_HSPL_ACTIVE_LOW
 100                                   | LTV_DPL_SAMPLE_RISING
 101                                   | LTV_EPL_ACTIVE_LOW
 102                                   | LTV_SS_RIGHT_TO_LEFT);
 103         ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));
 104         ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
 105                                   LTV_NW_INV_1LINE | LTV_FWI(3));
 106         ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);
 107         ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);
 108         ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0));
 109         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);
 110         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);
 111         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);
 112         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);
 113         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);
 114         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);
 115         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);
 116         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);
 117         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);
 118         ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);
 119         if (ret)
 120                 goto err_settings;
 121
 122         /* Wait more than 2 frames */
 123         msleep(20);
 124
 125         /* Display On Sequence */
 126         ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 127                                  LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE
 128                                  | LTV_POWER_ON | LTV_DRIVE_CURRENT(5)
 129                                  | LTV_SUPPLY_CURRENT(5));
 130         ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
 131                                   LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3));
 132         if (ret)
 133                 goto err_disp_on;
 134
 135         /* Display should now be ON. Phew. */
 136         return 0;
 137
 138 err_disp_on:
 139         /*
 140          * Try to recover. Error handling probably isn't very useful
 141          * at this point, just make a best effort to switch the panel
 142          * off.
 143          */
 144         ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 145                            LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
 146                            | LTV_SUPPLY_CURRENT(5));
 147         ltv350qv_write_reg(lcd, LTV_GATECTL2,
 148                            LTV_NW_INV_1LINE | LTV_FWI(3));
 149 err_settings:
 150 err_power2:
 151 err_power1:
 152         ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
 153         usleep_range(1000, 1100);
 154 err:
 155         ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
 156         return -EIO;
 157 }
 158
 159 static int ltv350qv_power_off(struct ltv350qv *lcd)
 160 {
 161         int ret;
 162
 163         /* Display Off Sequence */
 164         ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 165                                  LTV_VCOM_DISABLE
 166                                  | LTV_DRIVE_CURRENT(5)
 167                                  | LTV_SUPPLY_CURRENT(5));
 168         ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
 169                                   LTV_NW_INV_1LINE | LTV_FWI(3));
 170
 171         /* Power down setting 1 */
 172         ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
 173
 174         /* Wait at least 1 ms */
 175         usleep_range(1000, 1100);
 176
 177         /* Power down setting 2 */
 178         ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
 179
 180         /*
 181          * No point in trying to recover here. If we can't switch the
 182          * panel off, what are we supposed to do other than inform the
 183          * user about the failure?
 184          */
 185         if (ret)
 186                 return -EIO;
 187
 188         /* Display power should now be OFF */
 189         return 0;
 190 }
 191
 192 static int ltv350qv_power(struct ltv350qv *lcd, int power)
 193 {
 194         int ret = 0;
 195
 196         if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
 197                 ret = ltv350qv_power_on(lcd);
 198         else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
 199                 ret = ltv350qv_power_off(lcd);
 200
 201         if (!ret)
 202                 lcd->power = power;
 203
 204         return ret;
 205 }
 206
 207 static int ltv350qv_set_power(struct lcd_device *ld, int power)
 208 {
 209         struct ltv350qv *lcd = lcd_get_data(ld);
 210
 211         return ltv350qv_power(lcd, power);
 212 }
 213
 214 static int ltv350qv_get_power(struct lcd_device *ld)
 215 {
 216         struct ltv350qv *lcd = lcd_get_data(ld);
 217
 218         return lcd->power;
 219 }
 220
 221 static struct lcd_ops ltv_ops = {
 222         .get_power      = ltv350qv_get_power,
 223         .set_power      = ltv350qv_set_power,
 224 };
 225
 226 static int ltv350qv_probe(struct spi_device *spi)
 227 {
 228         struct ltv350qv *lcd;
 229         struct lcd_device *ld;
 230         int ret;
 231
 232         lcd = devm_kzalloc(&spi->dev, sizeof(struct ltv350qv), GFP_KERNEL);
 233         if (!lcd)
 234                 return -ENOMEM;
 235
 236         lcd->spi = spi;
 237         lcd->power = FB_BLANK_POWERDOWN;
 238         lcd->buffer = devm_kzalloc(&spi->dev, 8, GFP_KERNEL);
 239         if (!lcd->buffer)
 240                 return -ENOMEM;
 241
 242         ld = devm_lcd_device_register(&spi->dev, "ltv350qv", &spi->dev, lcd,
 243                                         &ltv_ops);
 244         if (IS_ERR(ld))
 245                 return PTR_ERR(ld);
 246
 247         lcd->ld = ld;
 248
 249         ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
 250         if (ret)
 251                 return ret;
 252
 253         spi_set_drvdata(spi, lcd);
 254
 255         return 0;
 256 }
 257
 258 static int ltv350qv_remove(struct spi_device *spi)
 259 {
 260         struct ltv350qv *lcd = spi_get_drvdata(spi);
 261
 262         ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
 263         return 0;
 264 }
 265
 266 #ifdef CONFIG_PM_SLEEP
 267 static int ltv350qv_suspend(struct device *dev)
 268 {
 269         struct ltv350qv *lcd = dev_get_drvdata(dev);
 270
 271         return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
 272 }
 273
 274 static int ltv350qv_resume(struct device *dev)
 275 {
 276         struct ltv350qv *lcd = dev_get_drvdata(dev);
 277
 278         return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
 279 }
 280 #endif
 281
 282 static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume);
 283
 284 /* Power down all displays on reboot, poweroff or halt */
 285 static void ltv350qv_shutdown(struct spi_device *spi)
 286 {
 287         struct ltv350qv *lcd = spi_get_drvdata(spi);
 288
 289         ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
 290 }
 291
 292 static struct spi_driver ltv350qv_driver = {
 293         .driver = {
 294                 .name           = "ltv350qv",
 295                 .pm             = &ltv350qv_pm_ops,
 296         },
 297
 298         .probe          = ltv350qv_probe,
 299         .remove         = ltv350qv_remove,
 300         .shutdown       = ltv350qv_shutdown,
 301 };
 302
 303 module_spi_driver(ltv350qv_driver);
 304
 305 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
 306 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
 307 MODULE_LICENSE("GPL");
 308 MODULE_ALIAS("spi:ltv350qv");