drivers/video/backlight/88pm860x_bl.c

   1 /*
   2  * Backlight driver for Marvell Semiconductor 88PM8606
   3  *
   4  * Copyright (C) 2009 Marvell International Ltd.
   5  *      Haojian Zhuang <haojian.zhuang@marvell.com>
   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 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/slab.h>
  16 #include <linux/fb.h>
  17 #include <linux/i2c.h>
  18 #include <linux/backlight.h>
  19 #include <linux/mfd/88pm860x.h>
  20 #include <linux/module.h>
  21
  22 #define MAX_BRIGHTNESS          (0xFF)
  23 #define MIN_BRIGHTNESS          (0)
  24
  25 #define CURRENT_BITMASK         (0x1F << 1)
  26
  27 struct pm860x_backlight_data {
  28         struct pm860x_chip *chip;
  29         struct i2c_client *i2c;
  30         int     current_brightness;
  31         int     port;
  32         int     pwm;
  33         int     iset;
  34         int     reg_duty_cycle;
  35         int     reg_always_on;
  36         int     reg_current;
  37 };
  38
  39 static int backlight_power_set(struct pm860x_chip *chip, int port,
  40                 int on)
  41 {
  42         int ret = -EINVAL;
  43
  44         switch (port) {
  45         case 0:
  46                 ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
  47                         pm8606_osc_disable(chip, WLED1_DUTY);
  48                 break;
  49         case 1:
  50                 ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
  51                         pm8606_osc_disable(chip, WLED2_DUTY);
  52                 break;
  53         case 2:
  54                 ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
  55                         pm8606_osc_disable(chip, WLED3_DUTY);
  56                 break;
  57         }
  58         return ret;
  59 }
  60
  61 static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
  62 {
  63         struct pm860x_backlight_data *data = bl_get_data(bl);
  64         struct pm860x_chip *chip = data->chip;
  65         unsigned char value;
  66         int ret;
  67
  68         if (brightness > MAX_BRIGHTNESS)
  69                 value = MAX_BRIGHTNESS;
  70         else
  71                 value = brightness;
  72
  73         if (brightness)
  74                 backlight_power_set(chip, data->port, 1);
  75
  76         ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
  77         if (ret < 0)
  78                 goto out;
  79
  80         if ((data->current_brightness == 0) && brightness) {
  81                 if (data->iset) {
  82                         ret = pm860x_set_bits(data->i2c, data->reg_current,
  83                                               CURRENT_BITMASK, data->iset);
  84                         if (ret < 0)
  85                                 goto out;
  86                 }
  87                 if (data->pwm) {
  88                         ret = pm860x_set_bits(data->i2c, PM8606_PWM,
  89                                               PM8606_PWM_FREQ_MASK, data->pwm);
  90                         if (ret < 0)
  91                                 goto out;
  92                 }
  93                 if (brightness == MAX_BRIGHTNESS) {
  94                         /* set WLED_ON bit as 100% */
  95                         ret = pm860x_set_bits(data->i2c, data->reg_always_on,
  96                                               PM8606_WLED_ON, PM8606_WLED_ON);
  97                 }
  98         } else {
  99                 if (brightness == MAX_BRIGHTNESS) {
 100                         /* set WLED_ON bit as 100% */
 101                         ret = pm860x_set_bits(data->i2c, data->reg_always_on,
 102                                               PM8606_WLED_ON, PM8606_WLED_ON);
 103                 } else {
 104                         /* clear WLED_ON bit since it's not 100% */
 105                         ret = pm860x_set_bits(data->i2c, data->reg_always_on,
 106                                               PM8606_WLED_ON, 0);
 107                 }
 108         }
 109         if (ret < 0)
 110                 goto out;
 111
 112         if (brightness == 0)
 113                 backlight_power_set(chip, data->port, 0);
 114
 115         dev_dbg(chip->dev, "set brightness %d\n", value);
 116         data->current_brightness = value;
 117         return 0;
 118 out:
 119         dev_dbg(chip->dev, "set brightness %d failure with return "
 120                 "value:%d\n", value, ret);
 121         return ret;
 122 }
 123
 124 static int pm860x_backlight_update_status(struct backlight_device *bl)
 125 {
 126         int brightness = bl->props.brightness;
 127
 128         if (bl->props.power != FB_BLANK_UNBLANK)
 129                 brightness = 0;
 130
 131         if (bl->props.fb_blank != FB_BLANK_UNBLANK)
 132                 brightness = 0;
 133
 134         if (bl->props.state & BL_CORE_SUSPENDED)
 135                 brightness = 0;
 136
 137         return pm860x_backlight_set(bl, brightness);
 138 }
 139
 140 static int pm860x_backlight_get_brightness(struct backlight_device *bl)
 141 {
 142         struct pm860x_backlight_data *data = bl_get_data(bl);
 143         struct pm860x_chip *chip = data->chip;
 144         int ret;
 145
 146         ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);
 147         if (ret < 0)
 148                 goto out;
 149         data->current_brightness = ret;
 150         dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
 151         return data->current_brightness;
 152 out:
 153         return -EINVAL;
 154 }
 155
 156 static const struct backlight_ops pm860x_backlight_ops = {
 157         .options        = BL_CORE_SUSPENDRESUME,
 158         .update_status  = pm860x_backlight_update_status,
 159         .get_brightness = pm860x_backlight_get_brightness,
 160 };
 161
 162 static int pm860x_backlight_probe(struct platform_device *pdev)
 163 {
 164         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 165         struct pm860x_backlight_pdata *pdata = pdev->dev.platform_data;
 166         struct pm860x_backlight_data *data;
 167         struct backlight_device *bl;
 168         struct resource *res;
 169         struct backlight_properties props;
 170         char name[MFD_NAME_SIZE];
 171         int ret = 0;
 172
 173         data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
 174                             GFP_KERNEL);
 175         if (data == NULL)
 176                 return -ENOMEM;
 177         res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
 178         if (!res) {
 179                 dev_err(&pdev->dev, "No REG resource for duty cycle\n");
 180                 ret = -ENXIO;
 181                 goto out;
 182         }
 183         data->reg_duty_cycle = res->start;
 184         res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
 185         if (!res) {
 186                 dev_err(&pdev->dev, "No REG resorce for always on\n");
 187                 ret = -ENXIO;
 188                 goto out;
 189         }
 190         data->reg_always_on = res->start;
 191         res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
 192         if (!res) {
 193                 dev_err(&pdev->dev, "No REG resource for current\n");
 194                 ret = -ENXIO;
 195                 goto out;
 196         }
 197         data->reg_current = res->start;
 198
 199         memset(name, 0, MFD_NAME_SIZE);
 200         sprintf(name, "backlight-%d", pdev->id);
 201         data->port = pdev->id;
 202         data->chip = chip;
 203         data->i2c = (chip->id == CHIP_PM8606) ? chip->client    \
 204                         : chip->companion;
 205         data->current_brightness = MAX_BRIGHTNESS;
 206         if (pdata) {
 207                 data->pwm = pdata->pwm;
 208                 data->iset = pdata->iset;
 209         }
 210
 211         memset(&props, 0, sizeof(struct backlight_properties));
 212         props.type = BACKLIGHT_RAW;
 213         props.max_brightness = MAX_BRIGHTNESS;
 214         bl = backlight_device_register(name, &pdev->dev, data,
 215                                         &pm860x_backlight_ops, &props);
 216         if (IS_ERR(bl)) {
 217                 dev_err(&pdev->dev, "failed to register backlight\n");
 218                 return PTR_ERR(bl);
 219         }
 220         bl->props.brightness = MAX_BRIGHTNESS;
 221
 222         platform_set_drvdata(pdev, bl);
 223
 224         /* read current backlight */
 225         ret = pm860x_backlight_get_brightness(bl);
 226         if (ret < 0)
 227                 goto out_brt;
 228
 229         backlight_update_status(bl);
 230         return 0;
 231 out_brt:
 232         backlight_device_unregister(bl);
 233 out:
 234         devm_kfree(&pdev->dev, data);
 235         return ret;
 236 }
 237
 238 static int pm860x_backlight_remove(struct platform_device *pdev)
 239 {
 240         struct backlight_device *bl = platform_get_drvdata(pdev);
 241
 242         backlight_device_unregister(bl);
 243         return 0;
 244 }
 245
 246 static struct platform_driver pm860x_backlight_driver = {
 247         .driver         = {
 248                 .name   = "88pm860x-backlight",
 249                 .owner  = THIS_MODULE,
 250         },
 251         .probe          = pm860x_backlight_probe,
 252         .remove         = pm860x_backlight_remove,
 253 };
 254
 255 module_platform_driver(pm860x_backlight_driver);
 256
 257 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
 258 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 259 MODULE_LICENSE("GPL");
 260 MODULE_ALIAS("platform:88pm860x-backlight");