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 #include <linux/slab.h>
  22
  23 #include <asm/mach/sharpsl_param.h>
  24
  25 #include <mach/tosa.h>
  26
  27 #define COMADJ_DEFAULT  97
  28
  29 #define DAC_CH1         0
  30 #define DAC_CH2         1
  31
  32 struct tosa_bl_data {
  33         struct i2c_client *i2c;
  34         struct backlight_device *bl;
  35
  36         int comadj;
  37 };
  38
  39 static void tosa_bl_set_backlight(struct tosa_bl_data *data, int brightness)
  40 {
  41         struct spi_device *spi = data->i2c->dev.platform_data;
  42
  43         i2c_smbus_write_byte_data(data->i2c, DAC_CH1, data->comadj);
  44
  45         /* SetBacklightDuty */
  46         i2c_smbus_write_byte_data(data->i2c, DAC_CH2, (u8)(brightness & 0xff));
  47
  48         /* SetBacklightVR */
  49         gpio_set_value(TOSA_GPIO_BL_C20MA, brightness & 0x100);
  50
  51         tosa_bl_enable(spi, brightness);
  52 }
  53
  54 static int tosa_bl_update_status(struct backlight_device *dev)
  55 {
  56         struct backlight_properties *props = &dev->props;
  57         struct tosa_bl_data *data = bl_get_data(dev);
  58         int power = max(props->power, props->fb_blank);
  59         int brightness = props->brightness;
  60
  61         if (power)
  62                 brightness = 0;
  63
  64         tosa_bl_set_backlight(data, brightness);
  65
  66         return 0;
  67 }
  68
  69 static int tosa_bl_get_brightness(struct backlight_device *dev)
  70 {
  71         struct backlight_properties *props = &dev->props;
  72
  73         return props->brightness;
  74 }
  75
  76 static const struct backlight_ops bl_ops = {
  77         .get_brightness         = tosa_bl_get_brightness,
  78         .update_status          = tosa_bl_update_status,
  79 };
  80
  81 static int tosa_bl_probe(struct i2c_client *client,
  82                 const struct i2c_device_id *id)
  83 {
  84         struct backlight_properties props;
  85         struct tosa_bl_data *data;
  86         int ret = 0;
  87
  88         data = devm_kzalloc(&client->dev, sizeof(struct tosa_bl_data),
  89                                 GFP_KERNEL);
  90         if (!data)
  91                 return -ENOMEM;
  92
  93         data->comadj = sharpsl_param.comadj == -1 ? COMADJ_DEFAULT : sharpsl_param.comadj;
  94
  95         ret = devm_gpio_request_one(&client->dev, TOSA_GPIO_BL_C20MA,
  96                                 GPIOF_OUT_INIT_LOW, "backlight");
  97         if (ret) {
  98                 dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
  99                 return ret;
 100         }
 101
 102         i2c_set_clientdata(client, data);
 103         data->i2c = client;
 104
 105         memset(&props, 0, sizeof(struct backlight_properties));
 106         props.type = BACKLIGHT_RAW;
 107         props.max_brightness = 512 - 1;
 108         data->bl = backlight_device_register("tosa-bl", &client->dev, data,
 109                                              &bl_ops, &props);
 110         if (IS_ERR(data->bl)) {
 111                 ret = PTR_ERR(data->bl);
 112                 goto err_reg;
 113         }
 114
 115         data->bl->props.brightness = 69;
 116         data->bl->props.power = FB_BLANK_UNBLANK;
 117
 118         backlight_update_status(data->bl);
 119
 120         return 0;
 121
 122 err_reg:
 123         data->bl = NULL;
 124         return ret;
 125 }
 126
 127 static int 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
 134         return 0;
 135 }
 136
 137 #ifdef CONFIG_PM
 138 static int tosa_bl_suspend(struct i2c_client *client, pm_message_t pm)
 139 {
 140         struct tosa_bl_data *data = i2c_get_clientdata(client);
 141
 142         tosa_bl_set_backlight(data, 0);
 143
 144         return 0;
 145 }
 146
 147 static int tosa_bl_resume(struct i2c_client *client)
 148 {
 149         struct tosa_bl_data *data = i2c_get_clientdata(client);
 150
 151         backlight_update_status(data->bl);
 152         return 0;
 153 }
 154 #else
 155 #define tosa_bl_suspend NULL
 156 #define tosa_bl_resume NULL
 157 #endif
 158
 159 static const struct i2c_device_id tosa_bl_id[] = {
 160         { "tosa-bl", 0 },
 161         { },
 162 };
 163
 164 static struct i2c_driver tosa_bl_driver = {
 165         .driver = {
 166                 .name           = "tosa-bl",
 167                 .owner          = THIS_MODULE,
 168         },
 169         .probe          = tosa_bl_probe,
 170         .remove         = tosa_bl_remove,
 171         .suspend        = tosa_bl_suspend,
 172         .resume         = tosa_bl_resume,
 173         .id_table       = tosa_bl_id,
 174 };
 175
 176 module_i2c_driver(tosa_bl_driver);
 177
 178 MODULE_AUTHOR("Dmitry Baryshkov");
 179 MODULE_LICENSE("GPL v2");
 180 MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
 181