drivers/video/backlight/l4f00242t03.c

   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
  23 struct 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
  33 static 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
  46 static 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
  85 static 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
  97 static 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
 104 static 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 <= LCD_POWER_REDUCED) {
 116                 if (priv->lcd_state <= LCD_POWER_REDUCED) {
 117                         /* Do nothing, the LCD is running */
 118                 } else if (priv->lcd_state < LCD_POWER_OFF) {
 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 == LCD_POWER_OFF */
 126                         l4f00242t03_lcd_init(spi);
 127                         priv->lcd_state = LCD_POWER_REDUCED_VSYNC_SUSPEND;
 128                         l4f00242t03_lcd_power_set(priv->ld, power);
 129                 }
 130         } else if (power < LCD_POWER_OFF) {
 131                 if (priv->lcd_state <= LCD_POWER_REDUCED) {
 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 < LCD_POWER_OFF) {
 139                         /* Do nothing, the LCD is already in standby */
 140                 } else {
 141                         /* priv->lcd_state == LCD_POWER_OFF */
 142                         l4f00242t03_lcd_init(spi);
 143                         priv->lcd_state = LCD_POWER_ON;
 144                         l4f00242t03_lcd_power_set(ld, power);
 145                 }
 146         } else {
 147                 /* power == LCD_POWER_OFF */
 148                 if (priv->lcd_state != LCD_POWER_OFF) {
 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
 161 static const struct lcd_ops l4f_ops = {
 162         .set_power      = l4f00242t03_lcd_power_set,
 163         .get_power      = l4f00242t03_lcd_power_get,
 164 };
 165
 166 static int l4f00242t03_probe(struct spi_device *spi)
 167 {
 168         struct l4f00242t03_priv *priv;
 169         int ret;
 170
 171         priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
 172                                 GFP_KERNEL);
 173         if (priv == NULL)
 174                 return -ENOMEM;
 175
 176         spi_set_drvdata(spi, priv);
 177         spi->bits_per_word = 9;
 178         ret = spi_setup(spi);
 179         if (ret < 0)
 180                 return dev_err_probe(&spi->dev, ret, "Unable to setup spi.\n");
 181
 182         priv->spi = spi;
 183
 184         priv->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
 185         if (IS_ERR(priv->reset))
 186                 return dev_err_probe(&spi->dev, PTR_ERR(priv->reset),
 187                                      "Unable to get the lcd l4f00242t03 reset gpio.\n");
 188         gpiod_set_consumer_name(priv->reset, "lcd l4f00242t03 reset");
 189
 190         priv->enable = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
 191         if (IS_ERR(priv->enable))
 192                 return dev_err_probe(&spi->dev, PTR_ERR(priv->enable),
 193                                      "Unable to get the lcd l4f00242t03 data en gpio.\n");
 194         gpiod_set_consumer_name(priv->enable, "lcd l4f00242t03 data enable");
 195
 196         priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
 197         if (IS_ERR(priv->io_reg))
 198                 return dev_err_probe(&spi->dev, PTR_ERR(priv->io_reg),
 199                                      "%s: Unable to get the IO regulator\n",
 200                                      __func__);
 201
 202         priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
 203         if (IS_ERR(priv->core_reg))
 204                 return dev_err_probe(&spi->dev, PTR_ERR(priv->core_reg),
 205                                      "%s: Unable to get the core regulator\n",
 206                                      __func__);
 207
 208         priv->ld = devm_lcd_device_register(&spi->dev, "l4f00242t03", &spi->dev,
 209                                         priv, &l4f_ops);
 210         if (IS_ERR(priv->ld))
 211                 return PTR_ERR(priv->ld);
 212
 213         /* Init the LCD */
 214         l4f00242t03_lcd_init(spi);
 215         priv->lcd_state = LCD_POWER_REDUCED_VSYNC_SUSPEND;
 216         l4f00242t03_lcd_power_set(priv->ld, LCD_POWER_ON);
 217
 218         dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
 219
 220         return 0;
 221 }
 222
 223 static void l4f00242t03_remove(struct spi_device *spi)
 224 {
 225         struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
 226
 227         l4f00242t03_lcd_power_set(priv->ld, LCD_POWER_OFF);
 228 }
 229
 230 static void l4f00242t03_shutdown(struct spi_device *spi)
 231 {
 232         struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
 233
 234         if (priv)
 235                 l4f00242t03_lcd_power_set(priv->ld, LCD_POWER_OFF);
 236
 237 }
 238
 239 static struct spi_driver l4f00242t03_driver = {
 240         .driver = {
 241                 .name   = "l4f00242t03",
 242         },
 243         .probe          = l4f00242t03_probe,
 244         .remove         = l4f00242t03_remove,
 245         .shutdown       = l4f00242t03_shutdown,
 246 };
 247
 248 module_spi_driver(l4f00242t03_driver);
 249
 250 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
 251 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
 252 MODULE_LICENSE("GPL v2");