LXR linux/drivers/video/backlight/tosa

   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
  32struct tosa_bl_data {
  33        struct i2c_client *i2c;
  34        struct backlight_device *bl;
  35
  36        int comadj;
  37};
  38
  39static 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
  54static int tosa_bl_update_status(struct backlight_device *dev)
  55{
  56        struct backlight_properties *props = &dev->props;
  57        struct tosa_bl_data *data = dev_get_drvdata(&dev->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
  69static int tosa_bl_get_brightness(struct backlight_device *dev)
  70{
  71        struct backlight_properties *props = &dev->props;
  72
  73        return props->brightness;
  74}
  75
  76static const struct backlight_ops bl_ops = {
  77        .get_brightness         = tosa_bl_get_brightness,
  78        .update_status          = tosa_bl_update_status,
  79};
  80
  81static int __devinit 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 = kzalloc(sizeof(struct tosa_bl_data), GFP_KERNEL);
  86        int ret = 0;
  87        if (!data)
  88                return -ENOMEM;
  89
  90        data->comadj = sharpsl_param.comadj == -1 ? COMADJ_DEFAULT : sharpsl_param.comadj;
  91
  92        ret = gpio_request(TOSA_GPIO_BL_C20MA, "backlight");
  93        if (ret) {
  94                dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
  95                goto err_gpio_bl;
  96        }
  97        ret = gpio_direction_output(TOSA_GPIO_BL_C20MA, 0);
  98        if (ret)
  99                goto err_gpio_dir;
 100
 101        i2c_set_clientdata(client, data);
 102        data->i2c = client;
 103
 104        memset(&props, 0, sizeof(struct backlight_properties));
 105        props.type = BACKLIGHT_RAW;
 106        props.max_brightness = 512 - 1;
 107        data->bl = backlight_device_register("tosa-bl", &client->dev, data,
 108                                             &bl_ops, &props);
 109        if (IS_ERR(data->bl)) {
 110                ret = PTR_ERR(data->bl);
 111                goto err_reg;
 112        }
 113
 114        data->bl->props.brightness = 69;
 115        data->bl->props.power = FB_BLANK_UNBLANK;
 116
 117        backlight_update_status(data->bl);
 118
 119        return 0;
 120
 121err_reg:
 122        data->bl = NULL;
 123err_gpio_dir:
 124        gpio_free(TOSA_GPIO_BL_C20MA);
 125err_gpio_bl:
 126        kfree(data);
 127        return ret;
 128}
 129
 130static int __devexit tosa_bl_remove(struct i2c_client *client)
 131{
 132        struct tosa_bl_data *data = i2c_get_clientdata(client);
 133
 134        backlight_device_unregister(data->bl);
 135        data->bl = NULL;
 136
 137        gpio_free(TOSA_GPIO_BL_C20MA);
 138
 139        kfree(data);
 140
 141        return 0;
 142}
 143
 144#ifdef CONFIG_PM
 145static int tosa_bl_suspend(struct i2c_client *client, pm_message_t pm)
 146{
 147        struct tosa_bl_data *data = i2c_get_clientdata(client);
 148
 149        tosa_bl_set_backlight(data, 0);
 150
 151        return 0;
 152}
 153
 154static int tosa_bl_resume(struct i2c_client *client)
 155{
 156        struct tosa_bl_data *data = i2c_get_clientdata(client);
 157
 158        backlight_update_status(data->bl);
 159        return 0;
 160}
 161#else
 162#define tosa_bl_suspend NULL
 163#define tosa_bl_resume NULL
 164#endif
 165
 166static const struct i2c_device_id tosa_bl_id[] = {
 167        { "tosa-bl", 0 },
 168        { },
 169};
 170
 171
 172static struct i2c_driver tosa_bl_driver = {
 173        .driver = {
 174                .name           = "tosa-bl",
 175                .owner          = THIS_MODULE,
 176        },
 177        .probe          = tosa_bl_probe,
 178        .remove         = __devexit_p(tosa_bl_remove),
 179        .suspend        = tosa_bl_suspend,
 180        .resume         = tosa_bl_resume,
 181        .id_table       = tosa_bl_id,
 182};
 183
 184static int __init tosa_bl_init(void)
 185{
 186        return i2c_add_driver(&tosa_bl_driver);
 187}
 188
 189static void __exit tosa_bl_exit(void)
 190{
 191        i2c_del_driver(&tosa_bl_driver);
 192}
 193
 194module_init(tosa_bl_init);
 195module_exit(tosa_bl_exit);
 196
 197MODULE_AUTHOR("Dmitry Baryshkov");
 198MODULE_LICENSE("GPL v2");
 199MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
 200
 201