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         return pm860x_backlight_set(bl, backlight_get_brightness(bl));
 125 }
 126
 127 static int pm860x_backlight_get_brightness(struct backlight_device *bl)
 128 {
 129         struct pm860x_backlight_data *data = bl_get_data(bl);
 130         struct pm860x_chip *chip = data->chip;
 131         int ret;
 132
 133         ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);
 134         if (ret < 0)
 135                 goto out;
 136         data->current_brightness = ret;
 137         dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
 138         return data->current_brightness;
 139 out:
 140         return -EINVAL;
 141 }
 142
 143 static const struct backlight_ops pm860x_backlight_ops = {
 144         .options        = BL_CORE_SUSPENDRESUME,
 145         .update_status  = pm860x_backlight_update_status,
 146         .get_brightness = pm860x_backlight_get_brightness,
 147 };
 148
 149 #ifdef CONFIG_OF
 150 static int pm860x_backlight_dt_init(struct platform_device *pdev,
 151                                     struct pm860x_backlight_data *data,
 152                                     char *name)
 153 {
 154         struct device_node *nproot, *np;
 155         int iset = 0;
 156
 157         nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights");
 158         if (!nproot) {
 159                 dev_err(&pdev->dev, "failed to find backlights node\n");
 160                 return -ENODEV;
 161         }
 162         for_each_child_of_node(nproot, np) {
 163                 if (of_node_name_eq(np, name)) {
 164                         of_property_read_u32(np, "marvell,88pm860x-iset",
 165                                              &iset);
 166                         data->iset = PM8606_WLED_CURRENT(iset);
 167                         of_property_read_u32(np, "marvell,88pm860x-pwm",
 168                                              &data->pwm);
 169                         of_node_put(np);
 170                         break;
 171                 }
 172         }
 173         of_node_put(nproot);
 174         return 0;
 175 }
 176 #else
 177 #define pm860x_backlight_dt_init(x, y, z)       (-1)
 178 #endif
 179
 180 static int pm860x_backlight_probe(struct platform_device *pdev)
 181 {
 182         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 183         struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
 184         struct pm860x_backlight_data *data;
 185         struct backlight_device *bl;
 186         struct resource *res;
 187         struct backlight_properties props;
 188         char name[MFD_NAME_SIZE];
 189         int ret = 0;
 190
 191         data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
 192                             GFP_KERNEL);
 193         if (data == NULL)
 194                 return -ENOMEM;
 195         res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
 196         if (!res) {
 197                 dev_err(&pdev->dev, "No REG resource for duty cycle\n");
 198                 return -ENXIO;
 199         }
 200         data->reg_duty_cycle = res->start;
 201         res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
 202         if (!res) {
 203                 dev_err(&pdev->dev, "No REG resource for always on\n");
 204                 return -ENXIO;
 205         }
 206         data->reg_always_on = res->start;
 207         res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
 208         if (!res) {
 209                 dev_err(&pdev->dev, "No REG resource for current\n");
 210                 return -ENXIO;
 211         }
 212         data->reg_current = res->start;
 213
 214         memset(name, 0, MFD_NAME_SIZE);
 215         sprintf(name, "backlight-%d", pdev->id);
 216         data->port = pdev->id;
 217         data->chip = chip;
 218         data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
 219         data->current_brightness = MAX_BRIGHTNESS;
 220         if (pm860x_backlight_dt_init(pdev, data, name)) {
 221                 if (pdata) {
 222                         data->pwm = pdata->pwm;
 223                         data->iset = pdata->iset;
 224                 }
 225         }
 226
 227         memset(&props, 0, sizeof(struct backlight_properties));
 228         props.type = BACKLIGHT_RAW;
 229         props.max_brightness = MAX_BRIGHTNESS;
 230         bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,
 231                                         &pm860x_backlight_ops, &props);
 232         if (IS_ERR(bl)) {
 233                 dev_err(&pdev->dev, "failed to register backlight\n");
 234                 return PTR_ERR(bl);
 235         }
 236         bl->props.brightness = MAX_BRIGHTNESS;
 237
 238         platform_set_drvdata(pdev, bl);
 239
 240         /* read current backlight */
 241         ret = pm860x_backlight_get_brightness(bl);
 242         if (ret < 0)
 243                 return ret;
 244
 245         backlight_update_status(bl);
 246         return 0;
 247 }
 248
 249 static struct platform_driver pm860x_backlight_driver = {
 250         .driver         = {
 251                 .name   = "88pm860x-backlight",
 252         },
 253         .probe          = pm860x_backlight_probe,
 254 };
 255
 256 module_platform_driver(pm860x_backlight_driver);
 257
 258 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
 259 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 260 MODULE_LICENSE("GPL");
 261 MODULE_ALIAS("platform:88pm860x-backlight");