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/*

 * Power control for Samsung LTV350QV Quarter VGA LCD Panel

 *

 * Copyright (C) 2006, 2007 Atmel Corporation

 *

 * 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/delay.h>

#include <linux/err.h>

#include <linux/fb.h>

#include <linux/init.h>

#include <linux/lcd.h>

#include <linux/module.h>

#include <linux/spi/spi.h>

#include "ltv350qv.h"

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

struct ltv350qv {

        struct spi_device       *spi;

        u8                      *buffer;

        int                     power;

        struct lcd_device       *ld;

};

/*

 * The power-on and power-off sequences are taken from the

 * LTV350QV-F04 data sheet from Samsung. The register definitions are

 * taken from the S6F2002 command list also from Samsung. Both

 * documents are distributed with the AVR32 Linux BSP CD from Atmel.

 *

 * There's still some voodoo going on here, but it's a lot better than

 * in the first incarnation of the driver where all we had was the raw

 * numbers from the initialization sequence.

 */

static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)

{

        struct spi_message msg;

        struct spi_transfer index_xfer = {

                .len            = 3,

                .cs_change      = 1,

        };

        struct spi_transfer value_xfer = {

                .len            = 3,

        };

        spi_message_init(&msg);

        /* register index */

        lcd->buffer[0] = LTV_OPC_INDEX;

        lcd->buffer[1] = 0x00;

        lcd->buffer[2] = reg & 0x7f;

        index_xfer.tx_buf = lcd->buffer;

        spi_message_add_tail(&index_xfer, &msg);

        /* register value */

        lcd->buffer[4] = LTV_OPC_DATA;

        lcd->buffer[5] = val >> 8;

        lcd->buffer[6] = val;

        value_xfer.tx_buf = lcd->buffer + 4;

        spi_message_add_tail(&value_xfer, &msg);

        return spi_sync(lcd->spi, &msg);

}

/* The comments are taken straight from the data sheet */

static int ltv350qv_power_on(struct ltv350qv *lcd)

{

        int ret;

        /* Power On Reset Display off State */

        if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))

                goto err;

        msleep(15);

        /* Power Setting Function 1 */

        if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))

                goto err;

        if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))

                goto err_power1;

        /* Power Setting Function 2 */

        if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,

                               LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)

                               | LTV_SUPPLY_CURRENT(5)))

                goto err_power2;

        msleep(55);

        /* Instruction Setting */

        ret = ltv350qv_write_reg(lcd, LTV_IFCTL,

                                 LTV_NMD | LTV_REV | LTV_NL(0x1d));

        ret |= ltv350qv_write_reg(lcd, LTV_DATACTL,

                                  LTV_DS_SAME | LTV_CHS_480

                                  | LTV_DF_RGB | LTV_RGB_BGR);

        ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,

                                  LTV_VSPL_ACTIVE_LOW

                                  | LTV_HSPL_ACTIVE_LOW

                                  | LTV_DPL_SAMPLE_RISING

                                  | LTV_EPL_ACTIVE_LOW

                                  | LTV_SS_RIGHT_TO_LEFT);

        ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));

        ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,

                                  LTV_NW_INV_1LINE | LTV_FWI(3));

        ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);

        ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);

        ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0));

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);

        ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);

        if (ret)

                goto err_settings;

        /* Wait more than 2 frames */

        msleep(20);

        /* Display On Sequence */

        ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,

                                 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE

                                 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5)

                                 | LTV_SUPPLY_CURRENT(5));

        ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,

                                  LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3));

        if (ret)

                goto err_disp_on;

        /* Display should now be ON. Phew. */

        return 0;

err_disp_on:

        /*

         * Try to recover. Error handling probably isn't very useful

         * at this point, just make a best effort to switch the panel

         * off.

         */

        ltv350qv_write_reg(lcd, LTV_PWRCTL1,

                           LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)

                           | LTV_SUPPLY_CURRENT(5));

        ltv350qv_write_reg(lcd, LTV_GATECTL2,

                           LTV_NW_INV_1LINE | LTV_FWI(3));

err_settings:

err_power2:

err_power1:

        ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);

        msleep(1);

err:

        ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);

        return -EIO;

}

static int ltv350qv_power_off(struct ltv350qv *lcd)

{

        int ret;

        /* Display Off Sequence */

        ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,

                                 LTV_VCOM_DISABLE

                                 | LTV_DRIVE_CURRENT(5)

                                 | LTV_SUPPLY_CURRENT(5));

        ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,

                                  LTV_NW_INV_1LINE | LTV_FWI(3));

        /* Power down setting 1 */

        ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);

        /* Wait at least 1 ms */

        msleep(1);

        /* Power down setting 2 */

        ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);

        /*

         * No point in trying to recover here. If we can't switch the

         * panel off, what are we supposed to do other than inform the

         * user about the failure?

         */

        if (ret)

                return -EIO;

        /* Display power should now be OFF */

        return 0;

}

static int ltv350qv_power(struct ltv350qv *lcd, int power)

{

        int ret = 0;

        if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))

                ret = ltv350qv_power_on(lcd);

        else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))

                ret = ltv350qv_power_off(lcd);

        if (!ret)

                lcd->power = power;

        return ret;

}

static int ltv350qv_set_power(struct lcd_device *ld, int power)

{

        struct ltv350qv *lcd = lcd_get_data(ld);

        return ltv350qv_power(lcd, power);

}

static int ltv350qv_get_power(struct lcd_device *ld)

{

        struct ltv350qv *lcd = lcd_get_data(ld);

        return lcd->power;

}

static struct lcd_ops ltv_ops = {

        .get_power      = ltv350qv_get_power,

        .set_power      = ltv350qv_set_power,

};

static int __devinit ltv350qv_probe(struct spi_device *spi)

{

        struct ltv350qv *lcd;

        struct lcd_device *ld;

        int ret;

        lcd = kzalloc(sizeof(struct ltv350qv), GFP_KERNEL);

        if (!lcd)

                return -ENOMEM;

        lcd->spi = spi;

        lcd->power = FB_BLANK_POWERDOWN;

        lcd->buffer = kzalloc(8, GFP_KERNEL);

        ld = lcd_device_register("ltv350qv", &spi->dev, lcd, &ltv_ops);

        if (IS_ERR(ld)) {

                ret = PTR_ERR(ld);

                goto out_free_lcd;

        }

        lcd->ld = ld;

        ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);

        if (ret)

                goto out_unregister;

        dev_set_drvdata(&spi->dev, lcd);

        return 0;

out_unregister:

        lcd_device_unregister(ld);

out_free_lcd:

        kfree(lcd);

        return ret;

}

static int __devexit ltv350qv_remove(struct spi_device *spi)

{

        struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);

        ltv350qv_power(lcd, FB_BLANK_POWERDOWN);

        lcd_device_unregister(lcd->ld);

        kfree(lcd);

        return 0;

}

#ifdef CONFIG_PM

static int ltv350qv_suspend(struct spi_device *spi, pm_message_t state)

{

        struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);

        return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);

}

static int ltv350qv_resume(struct spi_device *spi)

{

        struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);

        return ltv350qv_power(lcd, FB_BLANK_UNBLANK);

}

#else

#define ltv350qv_suspend        NULL

#define ltv350qv_resume         NULL

#endif

/* Power down all displays on reboot, poweroff or halt */

static void ltv350qv_shutdown(struct spi_device *spi)

{

        struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);

        ltv350qv_power(lcd, FB_BLANK_POWERDOWN);

}

static struct spi_driver ltv350qv_driver = {

        .driver = {

                .name           = "ltv350qv",

                .bus            = &spi_bus_type,

                .owner          = THIS_MODULE,

        },

        .probe          = ltv350qv_probe,

        .remove         = __devexit_p(ltv350qv_remove),

        .shutdown       = ltv350qv_shutdown,

        .suspend        = ltv350qv_suspend,

        .resume         = ltv350qv_resume,

};

static int __init ltv350qv_init(void)

{

        return spi_register_driver(&ltv350qv_driver);

}

static void __exit ltv350qv_exit(void)

{

        spi_unregister_driver(&ltv350qv_driver);

}

module_init(ltv350qv_init);

module_exit(ltv350qv_exit);

MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");

MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");

MODULE_LICENSE("GPL");