Add TPS61163A driver using EasyScale Interface - V0 based on LK3.8

Signed-off-by: Daniel jeong <daniel.jeong@ti.com>

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 5ba2edf735760999c5490ec231c4fb6e2b9fb9d5..6963bcf34fda25f7dc76d91ab957b4b93cc42732 100644 (file)
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -432,6 +432,13 @@ config BACKLIGHT_TPS65217
          If you have a Texas Instruments TPS65217 say Y to enable the
          backlight driver.
 
+config BACKLIGHT_TPS61163A
+       tristate "TPS61163A Backlight"
+       depends on BACKLIGHT_CLASS_DEVICE
+       help
+         This supports TPS61163A Texas Instruments backlight driver
+         based on EasyScale Interface.
+
 config BACKLIGHT_AS3711
        tristate "AS3711 Backlight"
        depends on BACKLIGHT_CLASS_DEVICE && MFD_AS3711

diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 6ecab6863b994e839fec7d560e7609e52153c22e..c6abc3d7d13e2f2a96f3c6a33fb12667b17ce177 100644 (file)
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -54,4 +54,5 @@ obj-$(CONFIG_BACKLIGHT_PWM)           += pwm_bl.o
 obj-$(CONFIG_BACKLIGHT_SAHARA)         += kb3886_bl.o
 obj-$(CONFIG_BACKLIGHT_TOSA)           += tosa_bl.o
 obj-$(CONFIG_BACKLIGHT_TPS65217)       += tps65217_bl.o
+obj-$(CONFIG_BACKLIGHT_TPS61163A)      += tps61163a_bl.o
 obj-$(CONFIG_BACKLIGHT_WM831X)         += wm831x_bl.o

diff --git a/drivers/video/backlight/tps61163a_bl.c b/drivers/video/backlight/tps61163a_bl.c
new file mode 100644 (file)
index 0000000..4cd0a45
--- /dev/null
+++ b/drivers/video/backlight/tps61163a_bl.c
@@ -0,0 +1,245 @@
+/*
+ * Simple driver for Texas Instruments TPS61163A Backlight driver chip
+ *        using EasyScale Interface
+ *
+ * Copyright (C) 2014 Texas Instruments
+ * Author: Daniel Jeong  <gshark.jeong@gmail.com>
+ *            Ldd Mlp <ldd-mlp@list.ti.com>
+ *
+ * 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/backlight.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_data/tps61163a_bl.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define ADDRESS_TPS61163A      0x8F0000
+#define T_ES_DELAY_NS          100000
+#define T_ES_DETECTION_NS      260000
+#define T_START_NS                     2000
+#define T_EOS_NS                       2000
+#define T_RESET_MS                     3
+#define T_LOW_LOGIC_1_NS       3000
+#define T_LOW_LOGIC_0_NS       7000
+#define T_LOGIC_NS                     T_LOW_LOGIC_1_NS + T_LOW_LOGIC_0_NS
+
+#define BRIGHTNESS_MAX         0x1ff
+#define BRIGHTNESS_BMASK       0x1ff
+
+struct tps61163a_bl_data {
+       struct device *dev;
+       struct backlight_device *bled;
+       struct tps61163a_platform_data *pdata;
+
+       unsigned int en_gpio;
+};
+
+static int tps61163a_backlight_update_status(struct backlight_device *bl)
+{
+       struct tps61163a_bl_data *pchip = bl_get_data(bl);
+       unsigned int es_data, bmask;
+       
+       es_data = ADDRESS_TPS61163A | (bl->props.brightness & BRIGHTNESS_BMASK);
+
+       /* t_start : 2us high before data byte */
+       gpio_direction_output(pchip->en_gpio,1);
+       ndelay(T_START_NS);
+
+       for(bmask = 0x01; bmask < 0x1000000 ; bmask <<= 1){
+               int t_low;
+               if(es_data & bmask)
+                       t_low = T_LOW_LOGIC_1_NS;
+               else
+                       t_low = T_LOW_LOGIC_0_NS;
+
+               gpio_direction_output(pchip->en_gpio,0);
+               ndelay(t_low);
+               gpio_direction_output(pchip->en_gpio,1);
+               ndelay(T_LOGIC_NS - t_low);
+       }
+       gpio_direction_output(pchip->en_gpio,0);
+       /* t_eos : 2us low after address byte */
+       ndelay(T_EOS_NS);
+       gpio_direction_output(pchip->en_gpio,1);
+
+       
+       return bl->props.brightness;
+}
+
+static int tps61163a_backlight_get_brightness(struct backlight_device *bl)
+{
+       return bl->props.brightness;
+}
+
+static const struct backlight_ops tps61163a_bl_ops = {
+       .update_status  = tps61163a_backlight_update_status,
+       .get_brightness = tps61163a_backlight_get_brightness,
+};
+
+static ssize_t tps61163a_enable_store(struct device *dev,
+                                  struct device_attribute *devAttr,
+                                  const char *buf, size_t size)
+{
+       struct tps61163a_bl_data *pchip = dev_get_drvdata(dev);
+       unsigned int input;
+       int ret;
+
+       ret = kstrtouint(buf, 10, &input);
+       if (ret) 
+               return -EINVAL;
+
+       if(input == 0){
+               gpio_direction_output(pchip->en_gpio,0);
+               /* low more than 2.5 ms to reset */
+               mdelay(T_RESET_MS);
+       } else {
+               gpio_direction_output(pchip->en_gpio,1);
+               ndelay(T_ES_DELAY_NS);
+               gpio_direction_output(pchip->en_gpio,0);
+               ndelay(T_ES_DETECTION_NS);
+               gpio_direction_output(pchip->en_gpio,1);
+       }
+
+       return size;
+}
+static DEVICE_ATTR(enable, S_IWUSR, NULL, tps61163a_enable_store);
+
+#ifdef CONFIG_OF
+static int tps61163a_backlight_parse_dt(struct device *dev)
+{
+       struct device_node *node = dev->of_node;
+       u32 value;
+       int ret;
+
+       if (!node)
+               return -ENODEV;
+
+       ret = of_property_read_u32(node, "en_gpio_num",&value);
+       if (ret < 0)
+               return ret;     
+
+       return value;
+}
+
+static struct of_device_id tps61163a_backlight_of_match[] = {
+       { .compatible = TPS61163A_NAME },
+       { }
+};
+
+MODULE_DEVICE_TABLE(of, tps61163a_backlight_of_match);
+#else
+static int tps61163a_backlight_parse_dt(struct device *dev,
+                                 struct platform_tps61163a_backlight_data *data)
+{
+       return -ENODEV;
+}
+#endif
+
+static int tps61163a_backlight_probe(struct platform_device *pdev)
+{
+       struct tps61163a_bl_data *pchip;
+       struct backlight_properties props;
+       struct tps61163a_platform_data *pdata = dev_get_platdata(&pdev->dev);
+       int ret;
+       
+       pchip = devm_kzalloc(&pdev->dev,
+                            sizeof(struct tps61163a_bl_data), GFP_KERNEL);
+       if (pchip == NULL)
+               return -ENOMEM;
+       pchip->dev = &pdev->dev;
+
+       if(pdata == NULL){
+               pdata = devm_kzalloc(&pdev->dev,
+                            sizeof(struct tps61163a_platform_data), GFP_KERNEL);
+               if (pdata == NULL)
+                       return -ENOMEM;
+               pdata->en_gpio_num = tps61163a_backlight_parse_dt(&pdev->dev);
+               if(pdata->en_gpio_num < 0)
+                       return -EINVAL;
+       }
+
+       pchip->en_gpio = pdata->en_gpio_num;
+       pchip->pdata = pdata;
+
+       memset(&props, 0, sizeof(struct backlight_properties));
+       props.brightness = BRIGHTNESS_MAX;
+       props.max_brightness = BRIGHTNESS_MAX;
+       props.type = BACKLIGHT_RAW;
+       pchip->bled =
+               backlight_device_register(TPS61163A_NAME, pchip->dev, pchip,
+                                             &tps61163a_bl_ops, &props);
+               if (IS_ERR(pchip->bled))
+                       return PTR_ERR(pchip->bled);
+
+       /* for enable/disable */
+       ret = device_create_file(&(pchip->bled->dev),
+                                &dev_attr_enable);
+       if (ret < 0) {
+               dev_err(pchip->dev, "failed : add sysfs entries\n");
+               goto err_out;
+       }
+       platform_set_drvdata(pdev, pchip);
+
+       /* EasyScale init */
+       ret = gpio_request( pchip->en_gpio,"tps61163a");
+       if(ret ){
+               dev_err(pchip->dev, "failed : get gpio %d\n",pchip->en_gpio);
+               goto err_out;
+       }
+       /*
+        * ES Detection Window
+        *   - ES detect delay : 100us
+        *   - ES detect time  : 260us
+        * it should be finished in 1ms
+        */
+       gpio_direction_output(pchip->en_gpio,1);
+       ndelay(T_ES_DELAY_NS);
+       gpio_direction_output(pchip->en_gpio,0);
+       ndelay(T_ES_DETECTION_NS);
+       gpio_direction_output(pchip->en_gpio,1);
+
+       dev_info(pchip->dev,"tps61163a based on EasyScale is initialized\n");
+       return 0;
+
+err_out: 
+
+       backlight_device_unregister(pchip->bled);
+       return ret;
+}
+
+static int tps61163a_backlight_remove(struct platform_device *pdev)
+{
+       struct tps61163a_bl_data *pchip = platform_get_drvdata(pdev);
+
+       backlight_device_unregister(pchip->bled);
+       gpio_direction_output(pchip->en_gpio,0);
+       mdelay(T_RESET_MS);
+       return 0;
+}
+
+static struct platform_driver tps61163a_backlight_driver = {
+       .driver         = {
+               .name           = TPS61163A_NAME,
+               .owner          = THIS_MODULE,
+               .of_match_table = of_match_ptr(tps61163a_backlight_of_match),
+       },
+       .probe          = tps61163a_backlight_probe,
+       .remove         = tps61163a_backlight_remove,
+};
+
+module_platform_driver(tps61163a_backlight_driver);
+
+MODULE_DESCRIPTION("EasyScale based tps61163a Backlight Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:tps61163a_bl");

diff --git a/include/linux/platform_data/tps61163a_bl.h b/include/linux/platform_data/tps61163a_bl.h
new file mode 100644 (file)
index 0000000..3bf8724
--- /dev/null
+++ b/include/linux/platform_data/tps61163a_bl.h
@@ -0,0 +1,24 @@
+/*
+ * Simple driver for Texas Instruments TPS61163a Backlight driver chip
+ * Copyright (C) 2014 Texas Instruments
+ *
+ * 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.
+ *
+ */
+
+#ifndef __TPS61163A_H
+#define __TPS61163A_H
+
+#define TPS61163A_NAME "tps61163a_bl"
+
+/* struct tps61163a platform data
+ * @en_gpio_num : en pin gpio number
+ */
+struct tps61163a_platform_data {
+
+       unsigned int en_gpio_num;
+};
+
+#endif /* __TPS61163A_H */