path: root/recipes/linux/linux-2.6.18/ltv350qv-lcd-driver.patch

From nobody Mon Sep 17 00:00:00 2001
From: Håvard Skinnemoen <hskinnemoen@atmel.com>
Date: Wed Dec 21 14:52:09 2005 +0100
Subject: [PATCH] LTV350QV LCD driver

This patch adds support for powering on and off the Samsung LTV350QV
LCD panel via SPI. The driver responds to framebuffer power management,
it powers off the panel on reboot/halt/poweroff, and it can also be
controlled through sysfs. The panel is powered up when the module is
loaded and off when the module is unloaded.

---
 drivers/video/backlight/Kconfig    |   12 +
 drivers/video/backlight/Makefile   |    1 
 drivers/video/backlight/ltv350qv.c |  301 +++++++++++++++++++++++++++++++++++++
 3 files changed, 314 insertions(+)

Index: linux-2.6.18-avr32/drivers/video/backlight/Kconfig
===================================================================
--- linux-2.6.18-avr32.orig/drivers/video/backlight/Kconfig	2006-09-11 20:30:16.000000000 +0200
+++ linux-2.6.18-avr32/drivers/video/backlight/Kconfig	2006-09-11 20:31:24.000000000 +0200
@@ -42,6 +42,18 @@ config LCD_DEVICE
 	depends on LCD_CLASS_DEVICE
 	default y
 
+config LCD_LTV350QV
+	tristate "Samsung LTV350QV LCD Panel"
+	depends on LCD_DEVICE && SPI
+	default n
+	help
+	  If you have a Samsung LTV350QV LCD panel, say y to include a
+	  power control driver for it.  The panel starts up in power
+	  off state, so you need this driver in order to see any
+	  output.
+
+	  The LTV350QV panel is present on most ATSTK1000 boards.
+
 config BACKLIGHT_CORGI
 	tristate "Sharp Corgi Backlight Driver (SL Series)"
 	depends on BACKLIGHT_DEVICE && PXA_SHARPSL
Index: linux-2.6.18-avr32/drivers/video/backlight/Makefile
===================================================================
--- linux-2.6.18-avr32.orig/drivers/video/backlight/Makefile	2006-09-11 20:30:23.000000000 +0200
+++ linux-2.6.18-avr32/drivers/video/backlight/Makefile	2006-09-11 20:31:24.000000000 +0200
@@ -5,3 +5,4 @@ obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE) += 
 obj-$(CONFIG_BACKLIGHT_CORGI)	+= corgi_bl.o
 obj-$(CONFIG_BACKLIGHT_HP680)	+= hp680_bl.o
 obj-$(CONFIG_BACKLIGHT_LOCOMO)	+= locomolcd.o
+obj-$(CONFIG_LCD_LTV350QV)	+= ltv350qv.o
Index: linux-2.6.18-avr32/drivers/video/backlight/ltv350qv.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.18-avr32/drivers/video/backlight/ltv350qv.c	2006-09-11 20:31:24.000000000 +0200
@@ -0,0 +1,301 @@
+/*
+ * Power control for Samsung LTV350QV Quarter VGA LCD Panel
+ *
+ * Copyright (C) 2006 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/config.h>
+#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/reboot.h>
+#include <linux/spi/spi.h>
+
+#define POWER_IS_ON(pwr)	((pwr) <= FB_BLANK_NORMAL)
+
+struct ltv350qv {
+	struct spi_device *spi;
+	u8 *buffer;
+	int power;
+	struct semaphore lock;
+	struct lcd_device *ld;
+	struct list_head list;
+	int halt_done;
+};
+
+static LIST_HEAD(lcd_list);
+
+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,
+		.cs_change	= 1,
+	};
+
+	spi_message_init(&msg);
+
+	/* register index */
+	lcd->buffer[0] = 0x74;
+	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] = 0x76;
+	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);
+}
+
+#define write_reg(_spi, reg, val)				\
+	do {							\
+		ret = ltv350qv_write_reg(_spi, reg, val);	\
+		if (ret)					\
+			goto out;				\
+	} while (0)
+
+static int ltv350qv_power_on(struct ltv350qv *lcd)
+{
+	int ret;
+
+	write_reg(lcd,  9, 0x0000);
+	msleep(15);
+	write_reg(lcd,  9, 0x4000);
+	write_reg(lcd, 10, 0x2000);
+	write_reg(lcd,  9, 0x4055);
+	msleep(55);
+	write_reg(lcd,  1, 0x409d);
+	write_reg(lcd,  2, 0x0204);
+	write_reg(lcd,  3, 0x0100);
+	write_reg(lcd,  4, 0x3000);
+	write_reg(lcd,  5, 0x4003);
+	write_reg(lcd,  6, 0x000a);
+	write_reg(lcd,  7, 0x0021);
+	write_reg(lcd,  8, 0x0c00);
+	write_reg(lcd, 10, 0x0103);
+	write_reg(lcd, 11, 0x0301);
+	write_reg(lcd, 12, 0x1f0f);
+	write_reg(lcd, 13, 0x1f0f);
+	write_reg(lcd, 14, 0x0707);
+	write_reg(lcd, 15, 0x0307);
+	write_reg(lcd, 16, 0x0707);
+	write_reg(lcd, 17, 0x0000);
+	write_reg(lcd, 18, 0x0004);
+	write_reg(lcd, 19, 0x0000);
+
+	msleep(20);
+	write_reg(lcd,  9, 0x4a55);
+	write_reg(lcd,  5, 0x5003);
+
+out:
+	return ret;
+}
+
+static int ltv350qv_power_off(struct ltv350qv *lcd)
+{
+	int ret;
+
+	/* GON -> 0, POC -> 0 */
+	write_reg(lcd,  9, 0x4055);
+	/* DSC -> 0 */
+	write_reg(lcd,  5, 0x4003);
+	/* VCOMG -> 0 */
+	write_reg(lcd, 10, 0x2103);
+
+	msleep(1);
+
+	/* AP[2:0] -> 000 */
+	write_reg(lcd,  9, 0x4050);
+
+out:
+	return ret;
+}
+
+static int ltv350qv_power(struct ltv350qv *lcd, int power)
+{
+	int ret = 0;
+
+	down(&lcd->lock);
+
+	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;
+
+	up(&lcd->lock);
+
+	return ret;
+}
+
+static int ltv350qv_set_power(struct lcd_device *ld, int power)
+{
+	struct ltv350qv *lcd;
+
+	lcd = class_get_devdata(&ld->class_dev);
+	return ltv350qv_power(lcd, power);
+}
+
+static int ltv350qv_get_power(struct lcd_device *ld)
+{
+	struct ltv350qv *lcd;
+
+	lcd = class_get_devdata(&ld->class_dev);
+	return lcd->power;
+}
+
+static struct lcd_properties lcd_properties = {
+	.owner		= THIS_MODULE,
+	.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;
+	init_MUTEX(&lcd->lock);
+	lcd->buffer = kzalloc(8, GFP_KERNEL);
+
+	spi->mode = SPI_MODE_3;
+	spi->bits_per_word = 8;
+	ret = spi_setup(spi);
+	if (ret)
+		goto out_free_lcd;
+
+	ld = lcd_device_register("ltv350qv", lcd, &lcd_properties);
+	if (IS_ERR(ld)) {
+		ret = PTR_ERR(ld);
+		goto out_free_lcd;
+	}
+	lcd->ld = ld;
+
+	list_add(&lcd->list, &lcd_list);
+
+	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);
+	list_del(&lcd->list);
+	lcd_device_unregister(lcd->ld);
+	kfree(lcd);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int ltv350qv_suspend(struct spi_device *spi,
+			    pm_message_t state, u32 level)
+{
+	struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
+
+	if (level == SUSPEND_POWER_DOWN)
+		return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
+
+	return 0;
+}
+
+static int ltv350qv_resume(struct spi_device *spi, u32 level)
+{
+	struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
+
+	if (level == RESUME_POWER_ON)
+		return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
+
+	return 0;
+}
+#else
+#define ltv350qv_suspend	NULL
+#define ltv350qv_resume		NULL
+#endif
+
+/* Power down all displays on reboot, poweroff or halt */
+static int ltv350qv_halt(struct notifier_block *nb, unsigned long event,
+			 void *p)
+{
+	struct ltv350qv *lcd;
+
+	list_for_each_entry(lcd, &lcd_list, list) {
+		if (!lcd->halt_done)
+			ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
+		lcd->halt_done = 1;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct spi_driver ltv350qv_driver = {
+	.driver = {
+		.name		= "ltv350qv",
+		.bus		= &spi_bus_type,
+		.owner		= THIS_MODULE,
+	},
+
+	.probe		= ltv350qv_probe,
+	.remove		= __devexit_p(ltv350qv_remove),
+	.suspend	= ltv350qv_suspend,
+	.resume		= ltv350qv_resume,
+};
+
+static struct notifier_block ltv350qv_notifier = {
+	.notifier_call	= ltv350qv_halt,
+};
+
+static int __init ltv350qv_init(void)
+{
+	register_reboot_notifier(&ltv350qv_notifier);
+	return spi_register_driver(&ltv350qv_driver);
+}
+
+static void __exit ltv350qv_exit(void)
+{
+	unregister_reboot_notifier(&ltv350qv_notifier);
+	spi_unregister_driver(&ltv350qv_driver);
+}
+module_init(ltv350qv_init);
+module_exit(ltv350qv_exit);
+
+MODULE_AUTHOR("Atmel Norway");
+MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
+MODULE_LICENSE("GPL");