backlight: Add TLC59108 backlight control driver

This patch adds support for I2C configurable TLC59108 backlight
control driver.

Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 278aeaa925059673fdcefa7b1c243f5a92b41837..df9dac7048406b5eb4ed05f5d5675c3f99c4f2c6 100644 (file)
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -342,6 +342,14 @@ config BACKLIGHT_AAT2870
          If you have a AnalogicTech AAT2870 say Y to enable the
          backlight driver.
 
+config BACKLIGHT_TLC59108
+       tristate "TLC59108 LCD Backlight Driver"
+       depends on I2C && BACKLIGHT_CLASS_DEVICE
+       default n
+       help
+         If you have an LCD Panel with backlight control via TLC59108,
+         say Y to enable its LCD control driver.
+
 endif # BACKLIGHT_CLASS_DEVICE
 
 endif # BACKLIGHT_LCD_SUPPORT

diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index fdd1fc4b277062333846f4f9cd3ba75855d394a7..ba3147481f51d04c70d50f2f3e1e309e62d9fd32 100644 (file)
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -39,4 +39,5 @@ obj-$(CONFIG_BACKLIGHT_ADP8870)       += adp8870_bl.o
 obj-$(CONFIG_BACKLIGHT_88PM860X) += 88pm860x_bl.o
 obj-$(CONFIG_BACKLIGHT_PCF50633)       += pcf50633-backlight.o
 obj-$(CONFIG_BACKLIGHT_AAT2870) += aat2870_bl.o
+obj-$(CONFIG_BACKLIGHT_TLC59108)       += tlc59108.o
 

diff --git a/drivers/video/backlight/tlc59108.c b/drivers/video/backlight/tlc59108.c
new file mode 100755 (executable)
index 0000000..d7e9a4f
--- /dev/null
+++ b/drivers/video/backlight/tlc59108.c
@@ -0,0 +1,170 @@
+/*
+ * ti81xxhdmi_tlc59108.c
+ *
+ * Copyright (C) 2011 Texas Instruments
+ * Author: Senthil Natarajan
+ *
+ * tlc59108 HDMI Driver
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ * History:
+ *
+ * Senthil Natarajan<senthil.n@ti.com> July 2011 I2C driver for tlc59108
+ *                                              backlight control
+ */
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/backlight.h>
+#include <linux/fb.h>
+
+#define tlc59108_MODULE_NAME   "tlc59108"
+#define TLC59108_MODE1   0x00
+#define TLC59108_PWM2    0x04
+#define TLC59108_LEDOUT0 0x0c
+#define TLC59108_LEDOUT1 0x0d
+#define TLC59108_MAX_BRIGHTNESS 0xFF
+
+struct tlc59108_bl {
+       struct i2c_client *client;
+       struct backlight_device *bl;
+};
+
+static void tlc59108_bl_set_backlight(struct tlc59108_bl *data, int brightness)
+{
+       /* Set Mode1 Register */
+       i2c_smbus_write_byte_data(data->client, TLC59108_MODE1, 0x00);
+
+       /* Set LEDOUT0 Register */
+       i2c_smbus_write_byte_data(data->client, TLC59108_LEDOUT0, 0x21);
+
+       /* Set Backlight Duty Cycle*/
+       i2c_smbus_write_byte_data(data->client, TLC59108_PWM2,
+                                 brightness & 0xff);
+}
+
+static int tlc59108_bl_get_brightness(struct backlight_device *dev)
+{
+       struct backlight_properties *props = &dev->props;
+
+       return props->brightness;
+}
+
+static int tlc59108_bl_update_status(struct backlight_device *dev)
+{
+       struct backlight_properties *props = &dev->props;
+       struct tlc59108_bl *data = dev_get_drvdata(&dev->dev);
+       int brightness = props->brightness;
+
+       tlc59108_bl_set_backlight(data, brightness);
+
+       return 0;
+}
+
+static const struct backlight_ops bl_ops = {
+       .get_brightness         = tlc59108_bl_get_brightness,
+       .update_status          = tlc59108_bl_update_status,
+};
+
+static int tlc59108_probe(struct i2c_client *c, const struct i2c_device_id *id)
+{
+       struct backlight_properties props;
+       struct tlc59108_bl *data = kzalloc(sizeof(struct tlc59108_bl),
+                                          GFP_KERNEL);
+       int ret = 0;
+
+       if (!data)
+               return -ENOMEM;
+
+       i2c_set_clientdata(c, data);
+       data->client = c;
+
+       /* FIXME: This is definitely how it should be done.
+        * Someone more familiar with the framework needs to make it proper
+        */
+       if (cpu_is_am335x()) {
+               /* Set LED4 to always on in LEDOUT1 Register*/
+               ret = i2c_smbus_write_byte_data(data->client, TLC59108_LEDOUT1, 0x01);
+               if(ret < 0)
+                       pr_err("Could not set LED4 to fully on\n");
+       }
+
+       memset(&props, 0, sizeof(struct backlight_properties));
+       props.max_brightness = TLC59108_MAX_BRIGHTNESS;
+       props.type = BACKLIGHT_RAW;
+       data->bl = backlight_device_register("tlc59108-bl", &c->dev, data,
+                                            &bl_ops, &props);
+       if (IS_ERR(data->bl)) {
+               ret = PTR_ERR(data->bl);
+               goto err_reg;
+       }
+
+       data->bl->props.brightness = TLC59108_MAX_BRIGHTNESS;
+
+       backlight_update_status(data->bl);
+
+       return 0;
+
+err_reg:
+       data->bl = NULL;
+       kfree(data);
+       return ret;
+}
+
+static int tlc59108_remove(struct i2c_client *c)
+{
+       struct tlc59108_bl *data = i2c_get_clientdata(c);
+
+       backlight_device_unregister(data->bl);
+       data->bl = NULL;
+
+       kfree(data);
+
+       return 0;
+}
+
+/* I2C Device ID table */
+static const struct i2c_device_id tlc59108_id[] = {
+       { "tlc59108", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, tlc59108_id);
+
+/* I2C driver data */
+static struct i2c_driver tlc59108_driver = {
+       .driver = {
+               .owner = THIS_MODULE,
+               .name = tlc59108_MODULE_NAME,
+       },
+       .probe = tlc59108_probe,
+       .remove = tlc59108_remove,
+       .id_table = tlc59108_id,
+};
+
+static int __init tlc59108_init(void)
+{
+       return i2c_add_driver(&tlc59108_driver);
+}
+
+static void __exit tlc59108_exit(void)
+{
+       i2c_del_driver(&tlc59108_driver);
+}
+
+module_init(tlc59108_init);
+module_exit(tlc59108_exit);
+
+MODULE_DESCRIPTION("LCD/Backlight control for TLC59108");
+MODULE_AUTHOR("Senthil Natarajan <senthil.n@ti.com>");
+MODULE_LICENSE("GPL v2");