backlight: add support for Sharp SL-6000 LCD and backlight drivers

On Sharp SL-6000 lcd/backlight is a bit complex, so add two drivers
one for lcd-driving chip, other one for dac regulating the backlight
LEDS.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>

arch/arm/mach-pxa/include/mach/tosa.h

@@ -193,4 +193,7 @@
 #define TOSA_KEY_MAIL		KEY_MAIL
 #endif
 
+struct spi_device;
+extern int tosa_bl_enable(struct spi_device *spi, int enable);
+
 #endif /* _ASM_ARCH_TOSA_H_ */

drivers/video/backlight/Kconfig

@@ -75,6 +75,15 @@ config LCD_PLATFORM
 	  This driver provides a platform-device registered LCD power
 	  control interface.
 
+config LCD_TOSA
+	tristate "Sharp SL-6000 LCD Driver"
+	depends on LCD_CLASS_DEVICE && SPI
+	depends on MACH_TOSA
+	default n
+	help
+	  If you have an Sharp SL-6000 Zaurus say Y to enable a driver
+	  for its LCD.
+
 #
 # Backlight
 #
@@ -179,3 +188,12 @@ config BACKLIGHT_MBP_NVIDIA
          If you have an Apple Macbook Pro with Nvidia graphics hardware say Y
 	 to enable a driver for its backlight
 
+config BACKLIGHT_TOSA
+	tristate "Sharp SL-6000 Backlight Driver"
+	depends on BACKLIGHT_CLASS_DEVICE && I2C
+	depends on MACH_TOSA && LCD_TOSA
+	default n
+	help
+	  If you have an Sharp SL-6000 Zaurus say Y to enable a driver
+	  for its backlight
+

drivers/video/backlight/Makefile

@@ -7,6 +7,7 @@ obj-$(CONFIG_LCD_ILI9320)	   += ili9320.o
 obj-$(CONFIG_LCD_PLATFORM)	   += platform_lcd.o
 obj-$(CONFIG_LCD_VGG2432A4)	   += vgg2432a4.o
 obj-$(CONFIG_LCD_TDO24M)	   += tdo24m.o
+obj-$(CONFIG_LCD_TOSA)		   += tosa_lcd.o
 
 obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE) += backlight.o
 obj-$(CONFIG_BACKLIGHT_ATMEL_PWM)    += atmel-pwm-bl.o
@@ -18,4 +19,6 @@ obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o
 obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o
 obj-$(CONFIG_BACKLIGHT_PWM)	+= pwm_bl.o
 obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o
+obj-$(CONFIG_BACKLIGHT_TOSA)	+= tosa_bl.o
+
 

drivers/video/backlight/tosa_bl.c

@@ -0,0 +1,198 @@
+/*
+ *  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/gpio.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+
+#include <asm/mach/sharpsl_param.h>
+
+#include <mach/tosa.h>
+
+#define COMADJ_DEFAULT	97
+
+#define DAC_CH1		0
+#define DAC_CH2		1
+
+struct tosa_bl_data {
+	struct i2c_client *i2c;
+	struct backlight_device *bl;
+
+	int comadj;
+};
+
+static void tosa_bl_set_backlight(struct tosa_bl_data *data, int brightness)
+{
+	struct spi_device *spi = data->i2c->dev.platform_data;
+
+	i2c_smbus_write_byte_data(data->i2c, DAC_CH1, data->comadj);
+
+	/* SetBacklightDuty */
+	i2c_smbus_write_byte_data(data->i2c, DAC_CH2, (u8)(brightness & 0xff));
+
+	/* SetBacklightVR */
+	gpio_set_value(TOSA_GPIO_BL_C20MA, brightness & 0x100);
+
+	tosa_bl_enable(spi, brightness);
+}
+
+static int tosa_bl_update_status(struct backlight_device *dev)
+{
+	struct backlight_properties *props = &dev->props;
+	struct tosa_bl_data *data = dev_get_drvdata(&dev->dev);
+	int power = max(props->power, props->fb_blank);
+	int brightness = props->brightness;
+
+	if (power)
+		brightness = 0;
+
+	tosa_bl_set_backlight(data, brightness);
+
+	return 0;
+}
+
+static int tosa_bl_get_brightness(struct backlight_device *dev)
+{
+	struct backlight_properties *props = &dev->props;
+
+	return props->brightness;
+}
+
+static struct backlight_ops bl_ops = {
+	.get_brightness		= tosa_bl_get_brightness,
+	.update_status		= tosa_bl_update_status,
+};
+
+static int __devinit tosa_bl_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	struct tosa_bl_data *data = kzalloc(sizeof(struct tosa_bl_data), GFP_KERNEL);
+	int ret = 0;
+	if (!data)
+		return -ENOMEM;
+
+	data->comadj = sharpsl_param.comadj == -1 ? COMADJ_DEFAULT : sharpsl_param.comadj;
+
+	ret = gpio_request(TOSA_GPIO_BL_C20MA, "backlight");
+	if (ret) {
+		dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
+		goto err_gpio_bl;
+	}
+	ret = gpio_direction_output(TOSA_GPIO_BL_C20MA, 0);
+	if (ret)
+		goto err_gpio_dir;
+
+	i2c_set_clientdata(client, data);
+	data->i2c = client;
+
+	data->bl = backlight_device_register("tosa-bl", &client->dev,
+			data, &bl_ops);
+	if (IS_ERR(data->bl)) {
+		ret = PTR_ERR(data->bl);
+		goto err_reg;
+	}
+
+	data->bl->props.brightness = 69;
+	data->bl->props.max_brightness = 512 - 1;
+	data->bl->props.power = FB_BLANK_UNBLANK;
+
+	backlight_update_status(data->bl);
+
+	return 0;
+
+err_reg:
+	data->bl = NULL;
+	i2c_set_clientdata(client, NULL);
+err_gpio_dir:
+	gpio_free(TOSA_GPIO_BL_C20MA);
+err_gpio_bl:
+	kfree(data);
+	return ret;
+}
+
+static int __devexit tosa_bl_remove(struct i2c_client *client)
+{
+	struct tosa_bl_data *data = i2c_get_clientdata(client);
+
+	backlight_device_unregister(data->bl);
+	data->bl = NULL;
+	i2c_set_clientdata(client, NULL);
+
+	gpio_free(TOSA_GPIO_BL_C20MA);
+
+	kfree(data);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int tosa_bl_suspend(struct i2c_client *client, pm_message_t pm)
+{
+	struct tosa_bl_data *data = i2c_get_clientdata(client);
+
+	tosa_bl_set_backlight(data, 0);
+
+	return 0;
+}
+
+static int tosa_bl_resume(struct i2c_client *client)
+{
+	struct tosa_bl_data *data = i2c_get_clientdata(client);
+
+	backlight_update_status(data->bl);
+	return 0;
+}
+#else
+#define tosa_bl_suspend NULL
+#define tosa_bl_resume NULL
+#endif
+
+static const struct i2c_device_id tosa_bl_id[] = {
+	{ "tosa-bl", 0 },
+	{ },
+};
+
+
+static struct i2c_driver tosa_bl_driver = {
+	.driver = {
+		.name		= "tosa-bl",
+		.owner		= THIS_MODULE,
+	},
+	.probe		= tosa_bl_probe,
+	.remove		= __devexit_p(tosa_bl_remove),
+	.suspend	= tosa_bl_suspend,
+	.resume		= tosa_bl_resume,
+	.id_table	= tosa_bl_id,
+};
+
+static int __init tosa_bl_init(void)
+{
+	return i2c_add_driver(&tosa_bl_driver);
+}
+
+static void __exit tosa_bl_exit(void)
+{
+	i2c_del_driver(&tosa_bl_driver);
+}
+
+module_init(tosa_bl_init);
+module_exit(tosa_bl_exit);
+
+MODULE_AUTHOR("Dmitry Baryshkov");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
+