source: src/linux/universal/linux-3.2/drivers/video/backlight/tosa_lcd.c @ 18879

/*
 *  LCD / Backlight control code for Sharp SL-6000x (tosa)
 *
 *  Copyright (c) 2005          Dirk Opfer
 *  Copyright (c) 2007,2008     Dmitry Baryshkov
 *
 *  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.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/lcd.h>
#include <linux/fb.h>

#include <asm/mach/sharpsl_param.h>

#include <mach/tosa.h>

#define POWER_IS_ON(pwr)        ((pwr) <= FB_BLANK_NORMAL)

#define TG_REG0_VQV     0x0001
#define TG_REG0_COLOR   0x0002
#define TG_REG0_UD      0x0004
#define TG_REG0_LR      0x0008

#define DAC_BASE        0x4e

struct tosa_lcd_data {
        struct spi_device *spi;
        struct lcd_device *lcd;
        struct i2c_client *i2c;

        int lcd_power;
        bool is_vga;
};

static int tosa_tg_send(struct spi_device *spi, int adrs, uint8_t data)
{
        u8 buf[1];
        struct spi_message msg;
        struct spi_transfer xfer = {
                .len            = 1,
                .cs_change      = 1,
                .tx_buf         = buf,
        };

        buf[0] = ((adrs & 0x07) << 5) | (data & 0x1f);
        spi_message_init(&msg);
        spi_message_add_tail(&xfer, &msg);

        return spi_sync(spi, &msg);
}

int tosa_bl_enable(struct spi_device *spi, int enable)
{
        /* bl_enable GP04=1 otherwise GP04=0*/
        return tosa_tg_send(spi, TG_GPODR2, enable? 0x01 : 0x00);
}
EXPORT_SYMBOL(tosa_bl_enable);

static void tosa_lcd_tg_init(struct tosa_lcd_data *data)
{
        /* TG on */
        gpio_set_value(TOSA_GPIO_TG_ON, 0);

        mdelay(60);

        /* delayed 0clk TCTL signal for VGA */
        tosa_tg_send(data->spi, TG_TPOSCTL, 0x00);
        /* GPOS0=powercontrol, GPOS1=GPIO, GPOS2=TCTL */
        tosa_tg_send(data->spi, TG_GPOSR, 0x02);
}

static void tosa_lcd_tg_on(struct tosa_lcd_data *data)
{
        struct spi_device *spi = data->spi;
        int value = TG_REG0_COLOR | TG_REG0_UD | TG_REG0_LR;

        if (data->is_vga)
                value |= TG_REG0_VQV;

        tosa_tg_send(spi, TG_PNLCTL, value);

        /* TG LCD pannel power up */
        tosa_tg_send(spi, TG_PINICTL,0x4);
        mdelay(50);

        /* TG LCD GVSS */
        tosa_tg_send(spi, TG_PINICTL,0x0);

        if (!data->i2c) {
                /* after the pannel is powered up the first time, we can access the i2c bus */
                /* so probe for the DAC */
                struct i2c_adapter *adap = i2c_get_adapter(0);
                struct i2c_board_info info = {
                        .type   = "tosa-bl",
                        .addr   = DAC_BASE,
                        .platform_data = data->spi,
                };
                data->i2c = i2c_new_device(adap, &info);
        }
}

static void tosa_lcd_tg_off(struct tosa_lcd_data *data)
{
        struct spi_device *spi = data->spi;

        /* TG LCD VHSA off */
        tosa_tg_send(spi, TG_PINICTL,0x4);
        mdelay(50);

        /* TG LCD signal off */
        tosa_tg_send(spi, TG_PINICTL,0x6);
        mdelay(50);

        /* TG Off */
        gpio_set_value(TOSA_GPIO_TG_ON, 1);
        mdelay(100);
}

int tosa_lcd_set_power(struct lcd_device *lcd, int power)
{
        struct tosa_lcd_data *data = lcd_get_data(lcd);

        if (POWER_IS_ON(power) && !POWER_IS_ON(data->lcd_power))
                tosa_lcd_tg_on(data);

        if (!POWER_IS_ON(power) && POWER_IS_ON(data->lcd_power))
                tosa_lcd_tg_off(data);

        data->lcd_power = power;
        return 0;
}

static int tosa_lcd_get_power(struct lcd_device *lcd)
{
        struct tosa_lcd_data *data = lcd_get_data(lcd);

        return data->lcd_power;
}

static int tosa_lcd_set_mode(struct lcd_device *lcd, struct fb_videomode *mode)
{
        struct tosa_lcd_data *data = lcd_get_data(lcd);

        if (mode->xres == 320 || mode->yres == 320)
                data->is_vga = false;
        else
                data->is_vga = true;

        if (POWER_IS_ON(data->lcd_power))
                tosa_lcd_tg_on(data);

        return 0;
}

static struct lcd_ops tosa_lcd_ops = {
        .set_power = tosa_lcd_set_power,
        .get_power = tosa_lcd_get_power,
        .set_mode = tosa_lcd_set_mode,
};

static int __devinit tosa_lcd_probe(struct spi_device *spi)
{
        int ret;
        struct tosa_lcd_data *data;

        data = kzalloc(sizeof(struct tosa_lcd_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->is_vga = true; /* default to VGA mode */

        /*
         * bits_per_word cannot be configured in platform data
         */
        spi->bits_per_word = 8;

        ret = spi_setup(spi);
        if (ret < 0)
                goto err_spi;

        data->spi = spi;
        dev_set_drvdata(&spi->dev, data);

        ret = gpio_request(TOSA_GPIO_TG_ON, "tg #pwr");
        if (ret < 0)
                goto err_gpio_tg;

        mdelay(60);

        ret = gpio_direction_output(TOSA_GPIO_TG_ON, 0);
        if (ret < 0)
                goto err_gpio_dir;

        mdelay(60);
        tosa_lcd_tg_init(data);

        tosa_lcd_tg_on(data);

        data->lcd = lcd_device_register("tosa-lcd", &spi->dev, data,
                        &tosa_lcd_ops);

        if (IS_ERR(data->lcd)) {
                ret = PTR_ERR(data->lcd);
                data->lcd = NULL;
                goto err_register;
        }

        return 0;

err_register:
        tosa_lcd_tg_off(data);
err_gpio_dir:
        gpio_free(TOSA_GPIO_TG_ON);
err_gpio_tg:
        dev_set_drvdata(&spi->dev, NULL);
err_spi:
        kfree(data);
        return ret;
}

static int __devexit tosa_lcd_remove(struct spi_device *spi)
{
        struct tosa_lcd_data *data = dev_get_drvdata(&spi->dev);

        lcd_device_unregister(data->lcd);

        if (data->i2c)
                i2c_unregister_device(data->i2c);

        tosa_lcd_tg_off(data);

        gpio_free(TOSA_GPIO_TG_ON);
        dev_set_drvdata(&spi->dev, NULL);
        kfree(data);

        return 0;
}

#ifdef CONFIG_PM
static int tosa_lcd_suspend(struct spi_device *spi, pm_message_t state)
{
        struct tosa_lcd_data *data = dev_get_drvdata(&spi->dev);

        tosa_lcd_tg_off(data);

        return 0;
}

static int tosa_lcd_resume(struct spi_device *spi)
{
        struct tosa_lcd_data *data = dev_get_drvdata(&spi->dev);

        tosa_lcd_tg_init(data);
        if (POWER_IS_ON(data->lcd_power))
                tosa_lcd_tg_on(data);
        else
                tosa_lcd_tg_off(data);

        return 0;
}
#else
#define tosa_lcd_suspend        NULL
#define tosa_lcd_resume NULL
#endif

static struct spi_driver tosa_lcd_driver = {
        .driver = {
                .name           = "tosa-lcd",
                .owner          = THIS_MODULE,
        },
        .probe          = tosa_lcd_probe,
        .remove         = __devexit_p(tosa_lcd_remove),
        .suspend        = tosa_lcd_suspend,
        .resume         = tosa_lcd_resume,
};

static int __init tosa_lcd_init(void)
{
        return spi_register_driver(&tosa_lcd_driver);
}

static void __exit tosa_lcd_exit(void)
{
        spi_unregister_driver(&tosa_lcd_driver);
}

module_init(tosa_lcd_init);
module_exit(tosa_lcd_exit);

MODULE_AUTHOR("Dmitry Baryshkov");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
MODULE_ALIAS("spi:tosa-lcd");