drivers/video/backlight/88pm860x_bl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Backlight driver for Marvell Semiconductor 88PM8606
   4  *
   5  * Copyright (C) 2009 Marvell International Ltd.
   6  *      Haojian Zhuang <haojian.zhuang@marvell.com>
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/of.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/slab.h>
  14 #include <linux/fb.h>
  15 #include <linux/i2c.h>
  16 #include <linux/backlight.h>
  17 #include <linux/mfd/88pm860x.h>
  18 #include <linux/module.h>
  19
  20 #define MAX_BRIGHTNESS          (0xFF)
  21 #define MIN_BRIGHTNESS          (0)
  22
  23 #define CURRENT_BITMASK         (0x1F << 1)
  24
  25 struct pm860x_backlight_data {
  26         struct pm860x_chip *chip;
  27         struct i2c_client *i2c;
  28         int     current_brightness;
  29         int     port;
  30         int     pwm;
  31         int     iset;
  32         int     reg_duty_cycle;
  33         int     reg_always_on;
  34         int     reg_current;
  35 };
  36
  37 static int backlight_power_set(struct pm860x_chip *chip, int port,
  38                 int on)
  39 {
  40         int ret = -EINVAL;
  41
  42         switch (port) {
  43         case 0:
  44                 ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
  45                         pm8606_osc_disable(chip, WLED1_DUTY);
  46                 break;
  47         case 1:
  48                 ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
  49                         pm8606_osc_disable(chip, WLED2_DUTY);
  50                 break;
  51         case 2:
  52                 ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
  53                         pm8606_osc_disable(chip, WLED3_DUTY);
  54                 break;
  55         }
  56         return ret;
  57 }
  58
  59 static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
  60 {
  61         struct pm860x_backlight_data *data = bl_get_data(bl);
  62         struct pm860x_chip *chip = data->chip;
  63         unsigned char value;
  64         int ret;
  65
  66         if (brightness > MAX_BRIGHTNESS)
  67                 value = MAX_BRIGHTNESS;
  68         else
  69                 value = brightness;
  70
  71         if (brightness)
  72                 backlight_power_set(chip, data->port, 1);
  73
  74         ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
  75         if (ret < 0)
  76                 goto out;
  77
  78         if ((data->current_brightness == 0) && brightness) {
  79                 if (data->iset) {
  80                         ret = pm860x_set_bits(data->i2c, data->reg_current,
  81                                               CURRENT_BITMASK, data->iset);
  82                         if (ret < 0)
  83                                 goto out;
  84                 }
  85                 if (data->pwm) {
  86                         ret = pm860x_set_bits(data->i2c, PM8606_PWM,
  87                                               PM8606_PWM_FREQ_MASK, data->pwm);
  88                         if (ret < 0)
  89                                 goto out;
  90                 }
  91                 if (brightness == MAX_BRIGHTNESS) {
  92                         /* set WLED_ON bit as 100% */
  93                         ret = pm860x_set_bits(data->i2c, data->reg_always_on,
  94                                               PM8606_WLED_ON, PM8606_WLED_ON);
  95                 }
  96         } else {
  97                 if (brightness == MAX_BRIGHTNESS) {
  98                         /* set WLED_ON bit as 100% */
  99                         ret = pm860x_set_bits(data->i2c, data->reg_always_on,
 100                                               PM8606_WLED_ON, PM8606_WLED_ON);
 101                 } else {
 102                         /* clear WLED_ON bit since it's not 100% */
 103                         ret = pm860x_set_bits(data->i2c, data->reg_always_on,
 104                                               PM8606_WLED_ON, 0);
 105                 }
 106         }
 107         if (ret < 0)
 108                 goto out;
 109
 110         if (brightness == 0)
 111                 backlight_power_set(chip, data->port, 0);
 112
 113         dev_dbg(chip->dev, "set brightness %d\n", value);
 114         data->current_brightness = value;
 115         return 0;
 116 out:
 117         dev_dbg(chip->dev, "set brightness %d failure with return value: %d\n",
 118                 value, ret);
 119         return ret;
 120 }
 121
 122 static int pm860x_backlight_update_status(struct backlight_device *bl)
 123 {
 124         int brightness = bl->props.brightness;
 125
 126         if (bl->props.power != FB_BLANK_UNBLANK)
 127                 brightness = 0;
 128
 129         if (bl->props.fb_blank != FB_BLANK_UNBLANK)
 130                 brightness = 0;
 131
 132         if (bl->props.state & BL_CORE_SUSPENDED)
 133                 brightness = 0;
 134
 135         return pm860x_backlight_set(bl, brightness);
 136 }
 137
 138 static int pm860x_backlight_get_brightness(struct backlight_device *bl)
 139 {
 140         struct pm860x_backlight_data *data = bl_get_data(bl);
 141         struct pm860x_chip *chip = data->chip;
 142         int ret;
 143
 144         ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);
 145         if (ret < 0)
 146                 goto out;
 147         data->current_brightness = ret;
 148         dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
 149         return data->current_brightness;
 150 out:
 151         return -EINVAL;
 152 }
 153
 154 static const struct backlight_ops pm860x_backlight_ops = {
 155         .options        = BL_CORE_SUSPENDRESUME,
 156         .update_status  = pm860x_backlight_update_status,
 157         .get_brightness = pm860x_backlight_get_brightness,
 158 };
 159
 160 #ifdef CONFIG_OF
 161 static int pm860x_backlight_dt_init(struct platform_device *pdev,
 162                                     struct pm860x_backlight_data *data,
 163                                     char *name)
 164 {
 165         struct device_node *nproot, *np;
 166         int iset = 0;
 167
 168         nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights");
 169         if (!nproot) {
 170                 dev_err(&pdev->dev, "failed to find backlights node\n");
 171                 return -ENODEV;
 172         }
 173         for_each_child_of_node(nproot, np) {
 174                 if (of_node_name_eq(np, name)) {
 175                         of_property_read_u32(np, "marvell,88pm860x-iset",
 176                                              &iset);
 177                         data->iset = PM8606_WLED_CURRENT(iset);
 178                         of_property_read_u32(np, "marvell,88pm860x-pwm",
 179                                              &data->pwm);
 180                         of_node_put(np);
 181                         break;
 182                 }
 183         }
 184         of_node_put(nproot);
 185         return 0;
 186 }
 187 #else
 188 #define pm860x_backlight_dt_init(x, y, z)       (-1)
 189 #endif
 190
 191 static int pm860x_backlight_probe(struct platform_device *pdev)
 192 {
 193         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 194         struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
 195         struct pm860x_backlight_data *data;
 196         struct backlight_device *bl;
 197         struct resource *res;
 198         struct backlight_properties props;
 199         char name[MFD_NAME_SIZE];
 200         int ret = 0;
 201
 202         data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
 203                             GFP_KERNEL);
 204         if (data == NULL)
 205                 return -ENOMEM;
 206         res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
 207         if (!res) {
 208                 dev_err(&pdev->dev, "No REG resource for duty cycle\n");
 209                 return -ENXIO;
 210         }
 211         data->reg_duty_cycle = res->start;
 212         res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
 213         if (!res) {
 214                 dev_err(&pdev->dev, "No REG resource for always on\n");
 215                 return -ENXIO;
 216         }
 217         data->reg_always_on = res->start;
 218         res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
 219         if (!res) {
 220                 dev_err(&pdev->dev, "No REG resource for current\n");
 221                 return -ENXIO;
 222         }
 223         data->reg_current = res->start;
 224
 225         memset(name, 0, MFD_NAME_SIZE);
 226         sprintf(name, "backlight-%d", pdev->id);
 227         data->port = pdev->id;
 228         data->chip = chip;
 229         data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
 230         data->current_brightness = MAX_BRIGHTNESS;
 231         if (pm860x_backlight_dt_init(pdev, data, name)) {
 232                 if (pdata) {
 233                         data->pwm = pdata->pwm;
 234                         data->iset = pdata->iset;
 235                 }
 236         }
 237
 238         memset(&props, 0, sizeof(struct backlight_properties));
 239         props.type = BACKLIGHT_RAW;
 240         props.max_brightness = MAX_BRIGHTNESS;
 241         bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,
 242                                         &pm860x_backlight_ops, &props);
 243         if (IS_ERR(bl)) {
 244                 dev_err(&pdev->dev, "failed to register backlight\n");
 245                 return PTR_ERR(bl);
 246         }
 247         bl->props.brightness = MAX_BRIGHTNESS;
 248
 249         platform_set_drvdata(pdev, bl);
 250
 251         /* read current backlight */
 252         ret = pm860x_backlight_get_brightness(bl);
 253         if (ret < 0)
 254                 return ret;
 255
 256         backlight_update_status(bl);
 257         return 0;
 258 }
 259
 260 static struct platform_driver pm860x_backlight_driver = {
 261         .driver         = {
 262                 .name   = "88pm860x-backlight",
 263         },
 264         .probe          = pm860x_backlight_probe,
 265 };
 266
 267 module_platform_driver(pm860x_backlight_driver);
 268
 269 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
 270 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 271 MODULE_LICENSE("GPL");
 272 MODULE_ALIAS("platform:88pm860x-backlight");