- 根目录:
- drivers
- video
- backlight
- ltv350qv.c
/*
* 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/slab.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);
if (!lcd->buffer) {
ret = -ENOMEM;
goto out_free_lcd;
}
ld = lcd_device_register("ltv350qv", &spi->dev, lcd, <v_ops);
if (IS_ERR(ld)) {
ret = PTR_ERR(ld);
goto out_free_buffer;
}
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_buffer:
kfree(lcd->buffer);
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->buffer);
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(<v350qv_driver);
}
static void __exit ltv350qv_exit(void)
{
spi_unregister_driver(<v350qv_driver);
}
module_init(ltv350qv_init);
module_exit(ltv350qv_exit);
MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:ltv350qv");