l4f00242t03.c

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/*
 * l4f00242t03.c -- support for Epson L4F00242T03 LCD
 *
 * Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved.
 *
 * Copyright (c) 2009 Alberto Panizzo <[email protected]>
 *  Inspired by Marek Vasut work in l4f00242t03.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#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.h>
#include <linux/lcd.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>

#include <linux/spi/spi.h>
#include <linux/spi/l4f00242t03.h>

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


static void l4f00242t03_reset(unsigned int gpio)
{
    pr_debug("l4f00242t03_reset.\n");
    gpio_set_value(gpio, 1);
    mdelay(100);
    gpio_set_value(gpio, 0);
    mdelay(10); /* tRES >= 100us */
    gpio_set_value(gpio, 1);
    mdelay(20);
}

#define param(x) ((x) | 0x100)

static void l4f00242t03_lcd_init(struct spi_device *spi)
{
    struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
    struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
    const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };

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

    regulator_set_voltage(priv->io_reg, 1800000, 1800000);
    regulator_enable(priv->io_reg);

    regulator_set_voltage(priv->core_reg, 2800000, 2800000);
    regulator_enable(priv->core_reg);

    l4f00242t03_reset(pdata->reset_gpio);

    gpio_set_value(pdata->data_enable_gpio, 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_pdata *pdata = spi->dev.platform_data;
    struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);

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

    gpio_set_value(pdata->data_enable_gpio, 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 <= FB_BLANK_NORMAL) {
        if (priv->lcd_state <= FB_BLANK_NORMAL) {
            /* Do nothing, the LCD is running */
        } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
            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 == FB_BLANK_POWERDOWN */
            l4f00242t03_lcd_init(spi);
            priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
            l4f00242t03_lcd_power_set(priv->ld, power);
        }
    } else if (power < FB_BLANK_POWERDOWN) {
        if (priv->lcd_state <= FB_BLANK_NORMAL) {
            /* 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 < FB_BLANK_POWERDOWN) {
            /* Do nothing, the LCD is already in standby */
        } else {
            /* priv->lcd_state == FB_BLANK_POWERDOWN */
            l4f00242t03_lcd_init(spi);
            priv->lcd_state = FB_BLANK_UNBLANK;
            l4f00242t03_lcd_power_set(ld, power);
        }
    } else {
        /* power == FB_BLANK_POWERDOWN */
        if (priv->lcd_state != FB_BLANK_POWERDOWN) {
            /* 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 struct lcd_ops l4f_ops = {
    .set_power  = l4f00242t03_lcd_power_set,
    .get_power  = l4f00242t03_lcd_power_get,
};

static int __devinit l4f00242t03_probe(struct spi_device *spi)
{
    struct l4f00242t03_priv *priv;
    struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
    int ret;

    if (pdata == NULL) {
        dev_err(&spi->dev, "Uninitialized platform data.\n");
        return -EINVAL;
    }

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

    if (priv == NULL) {
        dev_err(&spi->dev, "No memory for this device.\n");
        return -ENOMEM;
    }

    dev_set_drvdata(&spi->dev, priv);
    spi->bits_per_word = 9;
    spi_setup(spi);

    priv->spi = spi;

    ret = devm_gpio_request_one(&spi->dev, pdata->reset_gpio,
            GPIOF_OUT_INIT_HIGH, "lcd l4f00242t03 reset");
    if (ret) {
        dev_err(&spi->dev,
            "Unable to get the lcd l4f00242t03 reset gpio.\n");
        return ret;
    }

    ret = devm_gpio_request_one(&spi->dev, pdata->data_enable_gpio,
            GPIOF_OUT_INIT_LOW, "lcd l4f00242t03 data enable");
    if (ret) {
        dev_err(&spi->dev,
            "Unable to get the lcd l4f00242t03 data en gpio.\n");
        return ret;
    }

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

    priv->core_reg = regulator_get(&spi->dev, "vcore");
    if (IS_ERR(priv->core_reg)) {
        ret = PTR_ERR(priv->core_reg);
        dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
               __func__);
        goto err1;
    }

    priv->ld = lcd_device_register("l4f00242t03",
                    &spi->dev, priv, &l4f_ops);
    if (IS_ERR(priv->ld)) {
        ret = PTR_ERR(priv->ld);
        goto err2;
    }

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

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

    return 0;

err2:
    regulator_put(priv->core_reg);
err1:
    regulator_put(priv->io_reg);

    return ret;
}

static int __devexit l4f00242t03_remove(struct spi_device *spi)
{
    struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);

    l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
    lcd_device_unregister(priv->ld);

    dev_set_drvdata(&spi->dev, NULL);

    regulator_put(priv->io_reg);
    regulator_put(priv->core_reg);

    return 0;
}

static void l4f00242t03_shutdown(struct spi_device *spi)
{
    struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);

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

}

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

module_spi_driver(l4f00242t03_driver);

MODULE_AUTHOR("Alberto Panizzo <[email protected]>");
MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
MODULE_LICENSE("GPL v2");