Quelle  l4f00242t03.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * l4f00242t03.c -- support for Epson L4F00242T03 LCD
 *
 * Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved.
 *
 * Copyright (c) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
 * Inspired by Marek Vasut work in l4f00242t03.c
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/gpio/consumer.h>
#include <linux/lcd.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>

struct l4f00242t03_priv {
 struct spi_device *spi;
 struct lcd_device *ld;
 int lcd_state;
 struct regulator *io_reg;
 struct regulator *core_reg;
 struct gpio_desc *reset;
 struct gpio_desc *enable;
};

static void l4f00242t03_reset(struct gpio_desc *gpiod)
{
 pr_debug("l4f00242t03_reset.\n");
 gpiod_set_value(gpiod, 1);
 mdelay(100);
 gpiod_set_value(gpiod, 0);
 mdelay(10); /* tRES >= 100us */
 gpiod_set_value(gpiod, 1);
 mdelay(20);
}

#define param(x) ((x) | 0x100)

static void l4f00242t03_lcd_init(struct spi_device *spi)
{
 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
 const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
 int ret;

 dev_dbg(&spi->dev, "initializing LCD\n");

 ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
 if (ret) {
  dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
  return;
 }
 ret = regulator_enable(priv->io_reg);
 if (ret) {
  dev_err(&spi->dev, "failed to enable the IO regulator.\n");
  return;
 }

 ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
 if (ret) {
  dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
  regulator_disable(priv->io_reg);
  return;
 }
 ret = regulator_enable(priv->core_reg);
 if (ret) {
  dev_err(&spi->dev, "failed to enable the core regulator.\n");
  regulator_disable(priv->io_reg);
  return;
 }

 l4f00242t03_reset(priv->reset);

 gpiod_set_value(priv->enable, 1);
 msleep(60);
 spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
}

static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
{
 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);

 dev_dbg(&spi->dev, "Powering down LCD\n");

 gpiod_set_value(priv->enable, 0);

 regulator_disable(priv->io_reg);
 regulator_disable(priv->core_reg);
}

static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
{
 struct l4f00242t03_priv *priv = lcd_get_data(ld);

 return priv->lcd_state;
}

static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
{
 struct l4f00242t03_priv *priv = lcd_get_data(ld);
 struct spi_device *spi = priv->spi;

 const u16 slpout = 0x11;
 const u16 dison = 0x29;

 const u16 slpin = 0x10;
 const u16 disoff = 0x28;

 if (power <= LCD_POWER_REDUCED) {
  if (priv->lcd_state <= LCD_POWER_REDUCED) {
   /* Do nothing, the LCD is running */
  } else if (priv->lcd_state < LCD_POWER_OFF) {
   dev_dbg(&spi->dev, "Resuming LCD\n");

   spi_write(spi, (const u8 *)&slpout, sizeof(u16));
   msleep(60);
   spi_write(spi, (const u8 *)&dison, sizeof(u16));
  } else {
   /* priv->lcd_state == LCD_POWER_OFF */
   l4f00242t03_lcd_init(spi);
   priv->lcd_state = LCD_POWER_REDUCED_VSYNC_SUSPEND;
   l4f00242t03_lcd_power_set(priv->ld, power);
  }
 } else if (power < LCD_POWER_OFF) {
  if (priv->lcd_state <= LCD_POWER_REDUCED) {
   /* Send the display in standby */
   dev_dbg(&spi->dev, "Standby the LCD\n");

   spi_write(spi, (const u8 *)&disoff, sizeof(u16));
   msleep(60);
   spi_write(spi, (const u8 *)&slpin, sizeof(u16));
  } else if (priv->lcd_state < LCD_POWER_OFF) {
   /* Do nothing, the LCD is already in standby */
  } else {
   /* priv->lcd_state == LCD_POWER_OFF */
   l4f00242t03_lcd_init(spi);
   priv->lcd_state = LCD_POWER_ON;
   l4f00242t03_lcd_power_set(ld, power);
  }
 } else {
  /* power == LCD_POWER_OFF */
  if (priv->lcd_state != LCD_POWER_OFF) {
   /* Clear the screen before shutting down */
   spi_write(spi, (const u8 *)&disoff, sizeof(u16));
   msleep(60);
   l4f00242t03_lcd_powerdown(spi);
  }
 }

 priv->lcd_state = power;

 return 0;
}

static const struct lcd_ops l4f_ops = {
 .set_power = l4f00242t03_lcd_power_set,
 .get_power = l4f00242t03_lcd_power_get,
};

static int l4f00242t03_probe(struct spi_device *spi)
{
 struct l4f00242t03_priv *priv;
 int ret;

 priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
    GFP_KERNEL);
 if (priv == NULL)
  return -ENOMEM;

 spi_set_drvdata(spi, priv);
 spi->bits_per_word = 9;
 ret = spi_setup(spi);
 if (ret < 0)
  return dev_err_probe(&spi->dev, ret, "Unable to setup spi.\n");

 priv->spi = spi;

 priv->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
 if (IS_ERR(priv->reset))
  return dev_err_probe(&spi->dev, PTR_ERR(priv->reset),
         "Unable to get the lcd l4f00242t03 reset gpio.\n");
 gpiod_set_consumer_name(priv->reset, "lcd l4f00242t03 reset");

 priv->enable = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
 if (IS_ERR(priv->enable))
  return dev_err_probe(&spi->dev, PTR_ERR(priv->enable),
         "Unable to get the lcd l4f00242t03 data en gpio.\n");
 gpiod_set_consumer_name(priv->enable, "lcd l4f00242t03 data enable");

 priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
 if (IS_ERR(priv->io_reg))
  return dev_err_probe(&spi->dev, PTR_ERR(priv->io_reg),
         "%s: Unable to get the IO regulator\n",
         __func__);

 priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
 if (IS_ERR(priv->core_reg))
  return dev_err_probe(&spi->dev, PTR_ERR(priv->core_reg),
         "%s: Unable to get the core regulator\n",
         __func__);

 priv->ld = devm_lcd_device_register(&spi->dev, "l4f00242t03", &spi->dev,
     priv, &l4f_ops);
 if (IS_ERR(priv->ld))
  return PTR_ERR(priv->ld);

 /* Init the LCD */
 l4f00242t03_lcd_init(spi);
 priv->lcd_state = LCD_POWER_REDUCED_VSYNC_SUSPEND;
 l4f00242t03_lcd_power_set(priv->ld, LCD_POWER_ON);

 dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");

 return 0;
}

static void l4f00242t03_remove(struct spi_device *spi)
{
 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);

 l4f00242t03_lcd_power_set(priv->ld, LCD_POWER_OFF);
}

static void l4f00242t03_shutdown(struct spi_device *spi)
{
 struct l4f00242t03_priv *priv = spi_get_drvdata(spi);

 if (priv)
  l4f00242t03_lcd_power_set(priv->ld, LCD_POWER_OFF);

}

static struct spi_driver l4f00242t03_driver = {
 .driver = {
  .name = "l4f00242t03",
 },
 .probe  = l4f00242t03_probe,
 .remove  = l4f00242t03_remove,
 .shutdown = l4f00242t03_shutdown,
};

module_spi_driver(l4f00242t03_driver);

MODULE_AUTHOR("Alberto Panizzo ");
MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
MODULE_LICENSE("GPL v2");