LXR linux/drivers/leds/leds-acer-a500.c

   1// SPDX-License-Identifier: GPL-2.0+
   2
   3#include <linux/leds.h>
   4#include <linux/module.h>
   5#include <linux/platform_device.h>
   6#include <linux/regmap.h>
   7
   8#define A500_EC_LED_DELAY_USEC  (100 * 1000)
   9
  10enum {
  11        REG_RESET_LEDS = 0x40,
  12        REG_POWER_LED_ON = 0x42,
  13        REG_CHARGE_LED_ON = 0x43,
  14        REG_ANDROID_LEDS_OFF = 0x5a,
  15};
  16
  17struct a500_led {
  18        struct led_classdev cdev;
  19        const struct reg_sequence *enable_seq;
  20        struct a500_led *other;
  21        struct regmap *rmap;
  22};
  23
  24static const struct reg_sequence a500_ec_leds_reset_seq[] = {
  25        REG_SEQ(REG_RESET_LEDS, 0x0, A500_EC_LED_DELAY_USEC),
  26        REG_SEQ(REG_ANDROID_LEDS_OFF, 0x0, A500_EC_LED_DELAY_USEC),
  27};
  28
  29static const struct reg_sequence a500_ec_white_led_enable_seq[] = {
  30        REG_SEQ(REG_POWER_LED_ON, 0x0, A500_EC_LED_DELAY_USEC),
  31};
  32
  33static const struct reg_sequence a500_ec_orange_led_enable_seq[] = {
  34        REG_SEQ(REG_CHARGE_LED_ON, 0x0, A500_EC_LED_DELAY_USEC),
  35};
  36
  37static int a500_ec_led_brightness_set(struct led_classdev *led_cdev,
  38                                      enum led_brightness value)
  39{
  40        struct a500_led *led = container_of(led_cdev, struct a500_led, cdev);
  41        struct reg_sequence control_seq[2];
  42        unsigned int num_regs = 1;
  43
  44        if (value) {
  45                control_seq[0] = led->enable_seq[0];
  46        } else {
  47                /*
  48                 * There is no separate controls which can disable LEDs
  49                 * individually, there is only RESET_LEDS command that turns
  50                 * off both LEDs.
  51                 *
  52                 * RESET_LEDS turns off both LEDs, thus restore other LED if
  53                 * it's turned ON.
  54                 */
  55                if (led->other->cdev.brightness)
  56                        num_regs = 2;
  57
  58                control_seq[0] = a500_ec_leds_reset_seq[0];
  59                control_seq[1] = led->other->enable_seq[0];
  60        }
  61
  62        return regmap_multi_reg_write(led->rmap, control_seq, num_regs);
  63}
  64
  65static int a500_ec_leds_probe(struct platform_device *pdev)
  66{
  67        struct a500_led *white_led, *orange_led;
  68        struct regmap *rmap;
  69        int err;
  70
  71        rmap = dev_get_regmap(pdev->dev.parent, "KB930");
  72        if (!rmap)
  73                return -EINVAL;
  74
  75        /* reset and turn off LEDs */
  76        regmap_multi_reg_write(rmap, a500_ec_leds_reset_seq, 2);
  77
  78        white_led = devm_kzalloc(&pdev->dev, sizeof(*white_led), GFP_KERNEL);
  79        if (!white_led)
  80                return -ENOMEM;
  81
  82        white_led->cdev.name = "power:white";
  83        white_led->cdev.brightness_set_blocking = a500_ec_led_brightness_set;
  84        white_led->cdev.flags = LED_CORE_SUSPENDRESUME;
  85        white_led->cdev.max_brightness = 1;
  86        white_led->enable_seq = a500_ec_white_led_enable_seq;
  87        white_led->rmap = rmap;
  88
  89        orange_led = devm_kzalloc(&pdev->dev, sizeof(*orange_led), GFP_KERNEL);
  90        if (!orange_led)
  91                return -ENOMEM;
  92
  93        orange_led->cdev.name = "power:orange";
  94        orange_led->cdev.brightness_set_blocking = a500_ec_led_brightness_set;
  95        orange_led->cdev.flags = LED_CORE_SUSPENDRESUME;
  96        orange_led->cdev.max_brightness = 1;
  97        orange_led->enable_seq = a500_ec_orange_led_enable_seq;
  98        orange_led->rmap = rmap;
  99
 100        white_led->other = orange_led;
 101        orange_led->other = white_led;
 102
 103        err = devm_led_classdev_register(&pdev->dev, &white_led->cdev);
 104        if (err) {
 105                dev_err(&pdev->dev, "failed to register white LED\n");
 106                return err;
 107        }
 108
 109        err = devm_led_classdev_register(&pdev->dev, &orange_led->cdev);
 110        if (err) {
 111                dev_err(&pdev->dev, "failed to register orange LED\n");
 112                return err;
 113        }
 114
 115        return 0;
 116}
 117
 118static struct platform_driver a500_ec_leds_driver = {
 119        .driver = {
 120                .name = "acer-a500-iconia-leds",
 121        },
 122        .probe = a500_ec_leds_probe,
 123};
 124module_platform_driver(a500_ec_leds_driver);
 125
 126MODULE_DESCRIPTION("LED driver for Acer Iconia Tab A500 Power Button");
 127MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
 128MODULE_ALIAS("platform:acer-a500-iconia-leds");
 129MODULE_LICENSE("GPL");
 130