drivers/video/backlight/tosa_bl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  LCD / Backlight control code for Sharp SL-6000x (tosa)
   4  *
   5  *  Copyright (c) 2005          Dirk Opfer
   6  *  Copyright (c) 2007,2008     Dmitry Baryshkov
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/device.h>
  12 #include <linux/spi/spi.h>
  13 #include <linux/i2c.h>
  14 #include <linux/gpio.h>
  15 #include <linux/fb.h>
  16 #include <linux/backlight.h>
  17 #include <linux/slab.h>
  18
  19 #include <asm/mach/sharpsl_param.h>
  20
  21 #include "tosa_bl.h"
  22
  23 #define COMADJ_DEFAULT  97
  24
  25 #define DAC_CH1         0
  26 #define DAC_CH2         1
  27
  28 struct tosa_bl_data {
  29         struct i2c_client *i2c;
  30         struct backlight_device *bl;
  31         struct gpio_desc *gpio;
  32
  33         int comadj;
  34 };
  35
  36 static void tosa_bl_set_backlight(struct tosa_bl_data *data, int brightness)
  37 {
  38         struct spi_device *spi = dev_get_platdata(&data->i2c->dev);
  39
  40         i2c_smbus_write_byte_data(data->i2c, DAC_CH1, data->comadj);
  41
  42         /* SetBacklightDuty */
  43         i2c_smbus_write_byte_data(data->i2c, DAC_CH2, (u8)(brightness & 0xff));
  44
  45         /* SetBacklightVR */
  46         gpiod_set_value(data->gpio, brightness & 0x100);
  47
  48         tosa_bl_enable(spi, brightness);
  49 }
  50
  51 static int tosa_bl_update_status(struct backlight_device *dev)
  52 {
  53         struct backlight_properties *props = &dev->props;
  54         struct tosa_bl_data *data = bl_get_data(dev);
  55         int power = max(props->power, props->fb_blank);
  56         int brightness = props->brightness;
  57
  58         if (power)
  59                 brightness = 0;
  60
  61         tosa_bl_set_backlight(data, brightness);
  62
  63         return 0;
  64 }
  65
  66 static int tosa_bl_get_brightness(struct backlight_device *dev)
  67 {
  68         struct backlight_properties *props = &dev->props;
  69
  70         return props->brightness;
  71 }
  72
  73 static const struct backlight_ops bl_ops = {
  74         .get_brightness         = tosa_bl_get_brightness,
  75         .update_status          = tosa_bl_update_status,
  76 };
  77
  78 static int tosa_bl_probe(struct i2c_client *client,
  79                 const struct i2c_device_id *id)
  80 {
  81         struct backlight_properties props;
  82         struct tosa_bl_data *data;
  83         int ret = 0;
  84
  85         data = devm_kzalloc(&client->dev, sizeof(struct tosa_bl_data),
  86                                 GFP_KERNEL);
  87         if (!data)
  88                 return -ENOMEM;
  89
  90         data->comadj = sharpsl_param.comadj == -1 ? COMADJ_DEFAULT : sharpsl_param.comadj;
  91         data->gpio = devm_gpiod_get(&client->dev, "backlight", GPIOD_OUT_LOW);
  92         ret = PTR_ERR_OR_ZERO(data->gpio);
  93         if (ret) {
  94                 dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
  95                 return ret;
  96         }
  97
  98         i2c_set_clientdata(client, data);
  99         data->i2c = client;
 100
 101         memset(&props, 0, sizeof(struct backlight_properties));
 102         props.type = BACKLIGHT_RAW;
 103         props.max_brightness = 512 - 1;
 104         data->bl = devm_backlight_device_register(&client->dev, "tosa-bl",
 105                                                 &client->dev, data, &bl_ops,
 106                                                 &props);
 107         if (IS_ERR(data->bl)) {
 108                 ret = PTR_ERR(data->bl);
 109                 goto err_reg;
 110         }
 111
 112         data->bl->props.brightness = 69;
 113         data->bl->props.power = FB_BLANK_UNBLANK;
 114
 115         backlight_update_status(data->bl);
 116
 117         return 0;
 118
 119 err_reg:
 120         data->bl = NULL;
 121         return ret;
 122 }
 123
 124 static int tosa_bl_remove(struct i2c_client *client)
 125 {
 126         struct tosa_bl_data *data = i2c_get_clientdata(client);
 127
 128         data->bl = NULL;
 129         return 0;
 130 }
 131
 132 #ifdef CONFIG_PM_SLEEP
 133 static int tosa_bl_suspend(struct device *dev)
 134 {
 135         struct tosa_bl_data *data = dev_get_drvdata(dev);
 136
 137         tosa_bl_set_backlight(data, 0);
 138
 139         return 0;
 140 }
 141
 142 static int tosa_bl_resume(struct device *dev)
 143 {
 144         struct tosa_bl_data *data = dev_get_drvdata(dev);
 145
 146         backlight_update_status(data->bl);
 147         return 0;
 148 }
 149 #endif
 150
 151 static SIMPLE_DEV_PM_OPS(tosa_bl_pm_ops, tosa_bl_suspend, tosa_bl_resume);
 152
 153 static const struct i2c_device_id tosa_bl_id[] = {
 154         { "tosa-bl", 0 },
 155         { },
 156 };
 157 MODULE_DEVICE_TABLE(i2c, tosa_bl_id);
 158
 159 static struct i2c_driver tosa_bl_driver = {
 160         .driver = {
 161                 .name           = "tosa-bl",
 162                 .pm             = &tosa_bl_pm_ops,
 163         },
 164         .probe          = tosa_bl_probe,
 165         .remove         = tosa_bl_remove,
 166         .id_table       = tosa_bl_id,
 167 };
 168
 169 module_i2c_driver(tosa_bl_driver);
 170
 171 MODULE_AUTHOR("Dmitry Baryshkov");
 172 MODULE_LICENSE("GPL v2");
 173 MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
 174