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>

1 files changed, 198 insertions, 0 deletions

diff --git a/drivers/video/backlight/tosa_bl.c b/drivers/video/backlight/tosa_bl.c
new file mode 100644
index 00000000000..43edbada12d
--- /dev/null
+++ b/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");
+