drivers/video/backlight/tosa_bl.c

   1 /*
   2  *  LCD / Backlight control code for Sharp SL-6000x (tosa)
   3  *
   4  *  Copyright (c) 2005          Dirk Opfer
   5  *  Copyright (c) 2007,2008     Dmitry Baryshkov
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 as
   9  *  published by the Free Software Foundation.
  10  *
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/device.h>
  16 #include <linux/spi/spi.h>
  17 #include <linux/i2c.h>
  18 #include <linux/gpio.h>
  19 #include <linux/fb.h>
  20 #include <linux/backlight.h>
  21
  22 #include <asm/mach/sharpsl_param.h>
  23
  24 #include <mach/tosa.h>
  25
  26 #define COMADJ_DEFAULT  97
  27
  28 #define DAC_CH1         0
  29 #define DAC_CH2         1
  30
  31 struct tosa_bl_data {
  32         struct i2c_client *i2c;
  33         struct backlight_device *bl;
  34
  35         int comadj;
  36 };
  37
  38 static void tosa_bl_set_backlight(struct tosa_bl_data *data, int brightness)
  39 {
  40         struct spi_device *spi = data->i2c->dev.platform_data;
  41
  42         i2c_smbus_write_byte_data(data->i2c, DAC_CH1, data->comadj);
  43
  44         /* SetBacklightDuty */
  45         i2c_smbus_write_byte_data(data->i2c, DAC_CH2, (u8)(brightness & 0xff));
  46
  47         /* SetBacklightVR */
  48         gpio_set_value(TOSA_GPIO_BL_C20MA, brightness & 0x100);
  49
  50         tosa_bl_enable(spi, brightness);
  51 }
  52
  53 static int tosa_bl_update_status(struct backlight_device *dev)
  54 {
  55         struct backlight_properties *props = &dev->props;
  56         struct tosa_bl_data *data = dev_get_drvdata(&dev->dev);
  57         int power = max(props->power, props->fb_blank);
  58         int brightness = props->brightness;
  59
  60         if (power)
  61                 brightness = 0;
  62
  63         tosa_bl_set_backlight(data, brightness);
  64
  65         return 0;
  66 }
  67
  68 static int tosa_bl_get_brightness(struct backlight_device *dev)
  69 {
  70         struct backlight_properties *props = &dev->props;
  71
  72         return props->brightness;
  73 }
  74
  75 static struct backlight_ops bl_ops = {
  76         .get_brightness         = tosa_bl_get_brightness,
  77         .update_status          = tosa_bl_update_status,
  78 };
  79
  80 static int __devinit tosa_bl_probe(struct i2c_client *client,
  81                 const struct i2c_device_id *id)
  82 {
  83         struct tosa_bl_data *data = kzalloc(sizeof(struct tosa_bl_data), GFP_KERNEL);
  84         int ret = 0;
  85         if (!data)
  86                 return -ENOMEM;
  87
  88         data->comadj = sharpsl_param.comadj == -1 ? COMADJ_DEFAULT : sharpsl_param.comadj;
  89
  90         ret = gpio_request(TOSA_GPIO_BL_C20MA, "backlight");
  91         if (ret) {
  92                 dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
  93                 goto err_gpio_bl;
  94         }
  95         ret = gpio_direction_output(TOSA_GPIO_BL_C20MA, 0);
  96         if (ret)
  97                 goto err_gpio_dir;
  98
  99         i2c_set_clientdata(client, data);
 100         data->i2c = client;
 101
 102         data->bl = backlight_device_register("tosa-bl", &client->dev,
 103                         data, &bl_ops);
 104         if (IS_ERR(data->bl)) {
 105                 ret = PTR_ERR(data->bl);
 106                 goto err_reg;
 107         }
 108
 109         data->bl->props.brightness = 69;
 110         data->bl->props.max_brightness = 512 - 1;
 111         data->bl->props.power = FB_BLANK_UNBLANK;
 112
 113         backlight_update_status(data->bl);
 114
 115         return 0;
 116
 117 err_reg:
 118         data->bl = NULL;
 119         i2c_set_clientdata(client, NULL);
 120 err_gpio_dir:
 121         gpio_free(TOSA_GPIO_BL_C20MA);
 122 err_gpio_bl:
 123         kfree(data);
 124         return ret;
 125 }
 126
 127 static int __devexit tosa_bl_remove(struct i2c_client *client)
 128 {
 129         struct tosa_bl_data *data = i2c_get_clientdata(client);
 130
 131         backlight_device_unregister(data->bl);
 132         data->bl = NULL;
 133         i2c_set_clientdata(client, NULL);
 134
 135         gpio_free(TOSA_GPIO_BL_C20MA);
 136
 137         kfree(data);
 138
 139         return 0;
 140 }
 141
 142 #ifdef CONFIG_PM
 143 static int tosa_bl_suspend(struct i2c_client *client, pm_message_t pm)
 144 {
 145         struct tosa_bl_data *data = i2c_get_clientdata(client);
 146
 147         tosa_bl_set_backlight(data, 0);
 148
 149         return 0;
 150 }
 151
 152 static int tosa_bl_resume(struct i2c_client *client)
 153 {
 154         struct tosa_bl_data *data = i2c_get_clientdata(client);
 155
 156         backlight_update_status(data->bl);
 157         return 0;
 158 }
 159 #else
 160 #define tosa_bl_suspend NULL
 161 #define tosa_bl_resume NULL
 162 #endif
 163
 164 static const struct i2c_device_id tosa_bl_id[] = {
 165         { "tosa-bl", 0 },
 166         { },
 167 };
 168
 169
 170 static struct i2c_driver tosa_bl_driver = {
 171         .driver = {
 172                 .name           = "tosa-bl",
 173                 .owner          = THIS_MODULE,
 174         },
 175         .probe          = tosa_bl_probe,
 176         .remove         = __devexit_p(tosa_bl_remove),
 177         .suspend        = tosa_bl_suspend,
 178         .resume         = tosa_bl_resume,
 179         .id_table       = tosa_bl_id,
 180 };
 181
 182 static int __init tosa_bl_init(void)
 183 {
 184         return i2c_add_driver(&tosa_bl_driver);
 185 }
 186
 187 static void __exit tosa_bl_exit(void)
 188 {
 189         i2c_del_driver(&tosa_bl_driver);
 190 }
 191
 192 module_init(tosa_bl_init);
 193 module_exit(tosa_bl_exit);
 194
 195 MODULE_AUTHOR("Dmitry Baryshkov");
 196 MODULE_LICENSE("GPL v2");
 197 MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
 198