LXR linux/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
  20struct 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 */
  37static 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 */
  68static 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
 138err_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));
 149err_settings:
 150err_power2:
 151err_power1:
 152        ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
 153        usleep_range(1000, 1100);
 154err:
 155        ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
 156        return -EIO;
 157}
 158
 159static 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
 192static 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
 207static 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
 214static int ltv350qv_get_power(struct lcd_device *ld)
 215{
 216        struct ltv350qv *lcd = lcd_get_data(ld);
 217
 218        return lcd->power;
 219}
 220
 221static struct lcd_ops ltv_ops = {
 222        .get_power      = ltv350qv_get_power,
 223        .set_power      = ltv350qv_set_power,
 224};
 225
 226static 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
 258static 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
 267static 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
 274static 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
 282static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume);
 283
 284/* Power down all displays on reboot, poweroff or halt */
 285static 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
 292static 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
 303module_spi_driver(ltv350qv_driver);
 304
 305MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
 306MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
 307MODULE_LICENSE("GPL");
 308MODULE_ALIAS("spi:ltv350qv");
 309