linux/drivers/video/backlight/l4f00242t03.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * l4f00242t03.c -- support for Epson L4F00242T03 LCD
   4 *
   5 * Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved.
   6 *
   7 * Copyright (c) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
   8 *      Inspired by Marek Vasut work in l4f00242t03.c
   9 */
  10
  11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13#include <linux/device.h>
  14#include <linux/kernel.h>
  15#include <linux/delay.h>
  16#include <linux/module.h>
  17#include <linux/gpio/consumer.h>
  18#include <linux/lcd.h>
  19#include <linux/slab.h>
  20#include <linux/regulator/consumer.h>
  21#include <linux/spi/spi.h>
  22
  23struct l4f00242t03_priv {
  24        struct spi_device       *spi;
  25        struct lcd_device       *ld;
  26        int lcd_state;
  27        struct regulator *io_reg;
  28        struct regulator *core_reg;
  29        struct gpio_desc *reset;
  30        struct gpio_desc *enable;
  31};
  32
  33static void l4f00242t03_reset(struct gpio_desc *gpiod)
  34{
  35        pr_debug("l4f00242t03_reset.\n");
  36        gpiod_set_value(gpiod, 1);
  37        mdelay(100);
  38        gpiod_set_value(gpiod, 0);
  39        mdelay(10);     /* tRES >= 100us */
  40        gpiod_set_value(gpiod, 1);
  41        mdelay(20);
  42}
  43
  44#define param(x) ((x) | 0x100)
  45
  46static void l4f00242t03_lcd_init(struct spi_device *spi)
  47{
  48        struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
  49        const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
  50        int ret;
  51
  52        dev_dbg(&spi->dev, "initializing LCD\n");
  53
  54        ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
  55        if (ret) {
  56                dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
  57                return;
  58        }
  59        ret = regulator_enable(priv->io_reg);
  60        if (ret) {
  61                dev_err(&spi->dev, "failed to enable the IO regulator.\n");
  62                return;
  63        }
  64
  65        ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
  66        if (ret) {
  67                dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
  68                regulator_disable(priv->io_reg);
  69                return;
  70        }
  71        ret = regulator_enable(priv->core_reg);
  72        if (ret) {
  73                dev_err(&spi->dev, "failed to enable the core regulator.\n");
  74                regulator_disable(priv->io_reg);
  75                return;
  76        }
  77
  78        l4f00242t03_reset(priv->reset);
  79
  80        gpiod_set_value(priv->enable, 1);
  81        msleep(60);
  82        spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
  83}
  84
  85static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
  86{
  87        struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
  88
  89        dev_dbg(&spi->dev, "Powering down LCD\n");
  90
  91        gpiod_set_value(priv->enable, 0);
  92
  93        regulator_disable(priv->io_reg);
  94        regulator_disable(priv->core_reg);
  95}
  96
  97static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
  98{
  99        struct l4f00242t03_priv *priv = lcd_get_data(ld);
 100
 101        return priv->lcd_state;
 102}
 103
 104static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
 105{
 106        struct l4f00242t03_priv *priv = lcd_get_data(ld);
 107        struct spi_device *spi = priv->spi;
 108
 109        const u16 slpout = 0x11;
 110        const u16 dison = 0x29;
 111
 112        const u16 slpin = 0x10;
 113        const u16 disoff = 0x28;
 114
 115        if (power <= FB_BLANK_NORMAL) {
 116                if (priv->lcd_state <= FB_BLANK_NORMAL) {
 117                        /* Do nothing, the LCD is running */
 118                } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 119                        dev_dbg(&spi->dev, "Resuming LCD\n");
 120
 121                        spi_write(spi, (const u8 *)&slpout, sizeof(u16));
 122                        msleep(60);
 123                        spi_write(spi, (const u8 *)&dison, sizeof(u16));
 124                } else {
 125                        /* priv->lcd_state == FB_BLANK_POWERDOWN */
 126                        l4f00242t03_lcd_init(spi);
 127                        priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 128                        l4f00242t03_lcd_power_set(priv->ld, power);
 129                }
 130        } else if (power < FB_BLANK_POWERDOWN) {
 131                if (priv->lcd_state <= FB_BLANK_NORMAL) {
 132                        /* Send the display in standby */
 133                        dev_dbg(&spi->dev, "Standby the LCD\n");
 134
 135                        spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 136                        msleep(60);
 137                        spi_write(spi, (const u8 *)&slpin, sizeof(u16));
 138                } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
 139                        /* Do nothing, the LCD is already in standby */
 140                } else {
 141                        /* priv->lcd_state == FB_BLANK_POWERDOWN */
 142                        l4f00242t03_lcd_init(spi);
 143                        priv->lcd_state = FB_BLANK_UNBLANK;
 144                        l4f00242t03_lcd_power_set(ld, power);
 145                }
 146        } else {
 147                /* power == FB_BLANK_POWERDOWN */
 148                if (priv->lcd_state != FB_BLANK_POWERDOWN) {
 149                        /* Clear the screen before shutting down */
 150                        spi_write(spi, (const u8 *)&disoff, sizeof(u16));
 151                        msleep(60);
 152                        l4f00242t03_lcd_powerdown(spi);
 153                }
 154        }
 155
 156        priv->lcd_state = power;
 157
 158        return 0;
 159}
 160
 161static struct lcd_ops l4f_ops = {
 162        .set_power      = l4f00242t03_lcd_power_set,
 163        .get_power      = l4f00242t03_lcd_power_get,
 164};
 165
 166static int l4f00242t03_probe(struct spi_device *spi)
 167{
 168        struct l4f00242t03_priv *priv;
 169
 170        priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
 171                                GFP_KERNEL);
 172        if (priv == NULL)
 173                return -ENOMEM;
 174
 175        spi_set_drvdata(spi, priv);
 176        spi->bits_per_word = 9;
 177        spi_setup(spi);
 178
 179        priv->spi = spi;
 180
 181        priv->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
 182        if (IS_ERR(priv->reset)) {
 183                dev_err(&spi->dev,
 184                        "Unable to get the lcd l4f00242t03 reset gpio.\n");
 185                return PTR_ERR(priv->reset);
 186        }
 187        gpiod_set_consumer_name(priv->reset, "lcd l4f00242t03 reset");
 188
 189        priv->enable = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
 190        if (IS_ERR(priv->enable)) {
 191                dev_err(&spi->dev,
 192                        "Unable to get the lcd l4f00242t03 data en gpio.\n");
 193                return PTR_ERR(priv->enable);
 194        }
 195        gpiod_set_consumer_name(priv->enable, "lcd l4f00242t03 data enable");
 196
 197        priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
 198        if (IS_ERR(priv->io_reg)) {
 199                dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
 200                       __func__);
 201                return PTR_ERR(priv->io_reg);
 202        }
 203
 204        priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
 205        if (IS_ERR(priv->core_reg)) {
 206                dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
 207                       __func__);
 208                return PTR_ERR(priv->core_reg);
 209        }
 210
 211        priv->ld = devm_lcd_device_register(&spi->dev, "l4f00242t03", &spi->dev,
 212                                        priv, &l4f_ops);
 213        if (IS_ERR(priv->ld))
 214                return PTR_ERR(priv->ld);
 215
 216        /* Init the LCD */
 217        l4f00242t03_lcd_init(spi);
 218        priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
 219        l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
 220
 221        dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
 222
 223        return 0;
 224}
 225
 226static int l4f00242t03_remove(struct spi_device *spi)
 227{
 228        struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
 229
 230        l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 231        return 0;
 232}
 233
 234static void l4f00242t03_shutdown(struct spi_device *spi)
 235{
 236        struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
 237
 238        if (priv)
 239                l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
 240
 241}
 242
 243static struct spi_driver l4f00242t03_driver = {
 244        .driver = {
 245                .name   = "l4f00242t03",
 246        },
 247        .probe          = l4f00242t03_probe,
 248        .remove         = l4f00242t03_remove,
 249        .shutdown       = l4f00242t03_shutdown,
 250};
 251
 252module_spi_driver(l4f00242t03_driver);
 253
 254MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
 255MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
 256MODULE_LICENSE("GPL v2");
 257