leds-upboard.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * UP board LED driver.
  4 *
  5 * Copyright (c) AAEON. All rights reserved.
  6 * Copyright (C) 2024 Bootlin
  7 *
  8 * Author: Gary Wang <garywang@aaeon.com.tw>
  9 * Author: Thomas Richard <thomas.richard@bootlin.com>
 10 */
 11
 12#include <linux/device.h>
 13#include <linux/container_of.h>
 14#include <linux/leds.h>
 15#include <linux/mfd/upboard-fpga.h>
 16#include <linux/module.h>
 17#include <linux/platform_device.h>
 18#include <linux/regmap.h>
 19
 20#define led_cdev_to_led_upboard(c)	container_of(c, struct upboard_led, cdev)
 21
 22struct upboard_led {
 23	struct regmap_field *field;
 24	struct led_classdev cdev;
 25};
 26
 27struct upboard_led_profile {
 28	const char *name;
 29	unsigned int bit;
 30};
 31
 32static struct upboard_led_profile upboard_up_led_profile[] = {
 33	{ "upboard:yellow:" LED_FUNCTION_STATUS, 0 },
 34	{ "upboard:green:" LED_FUNCTION_STATUS, 1 },
 35	{ "upboard:red:" LED_FUNCTION_STATUS, 2 },
 36};
 37
 38static struct upboard_led_profile upboard_up2_led_profile[] = {
 39	{ "upboard:blue:" LED_FUNCTION_STATUS, 0 },
 40	{ "upboard:yellow:" LED_FUNCTION_STATUS, 1 },
 41	{ "upboard:green:" LED_FUNCTION_STATUS, 2 },
 42	{ "upboard:red:" LED_FUNCTION_STATUS, 3 },
 43};
 44
 45static enum led_brightness upboard_led_brightness_get(struct led_classdev *cdev)
 46{
 47	struct upboard_led *led = led_cdev_to_led_upboard(cdev);
 48	int brightness, ret;
 49
 50	ret = regmap_field_read(led->field, &brightness);
 51
 52	return ret ? LED_OFF : brightness;
 53};
 54
 55static int upboard_led_brightness_set(struct led_classdev *cdev, enum led_brightness brightness)
 56{
 57	struct upboard_led *led = led_cdev_to_led_upboard(cdev);
 58
 59	return regmap_field_write(led->field, brightness != LED_OFF);
 60};
 61
 62static int upboard_led_probe(struct platform_device *pdev)
 63{
 64	struct device *dev = &pdev->dev;
 65	struct upboard_fpga *fpga = dev_get_drvdata(dev->parent);
 66	struct upboard_led_profile *led_profile;
 67	struct upboard_led *led;
 68	int led_instances, ret, i;
 69
 70	switch (fpga->fpga_data->type) {
 71	case UPBOARD_UP_FPGA:
 72		led_profile = upboard_up_led_profile;
 73		led_instances = ARRAY_SIZE(upboard_up_led_profile);
 74		break;
 75	case UPBOARD_UP2_FPGA:
 76		led_profile = upboard_up2_led_profile;
 77		led_instances = ARRAY_SIZE(upboard_up2_led_profile);
 78		break;
 79	default:
 80		return dev_err_probe(dev, -EINVAL, "Unknown device type %d\n",
 81				     fpga->fpga_data->type);
 82	}
 83
 84	for (i = 0; i < led_instances; i++) {
 85		const struct reg_field fldconf = {
 86			.reg = UPBOARD_REG_FUNC_EN0,
 87			.lsb = led_profile[i].bit,
 88			.msb = led_profile[i].bit,
 89		};
 90
 91		led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
 92		if (!led)
 93			return -ENOMEM;
 94
 95		led->field = devm_regmap_field_alloc(&pdev->dev, fpga->regmap, fldconf);
 96		if (IS_ERR(led->field))
 97			return PTR_ERR(led->field);
 98
 99		led->cdev.brightness_get = upboard_led_brightness_get;
100		led->cdev.brightness_set_blocking = upboard_led_brightness_set;
101		led->cdev.max_brightness = LED_ON;
102
103		led->cdev.name = led_profile[i].name;
104
105		ret = devm_led_classdev_register(dev, &led->cdev);
106		if (ret)
107			return ret;
108	}
109
110	return 0;
111}
112
113static struct platform_driver upboard_led_driver = {
114	.driver = {
115		.name = "upboard-leds",
116	},
117	.probe = upboard_led_probe,
118};
119
120module_platform_driver(upboard_led_driver);
121
122MODULE_AUTHOR("Gary Wang <garywang@aaeon.com.tw>");
123MODULE_AUTHOR("Thomas Richard <thomas.richard@bootlin.com>");
124MODULE_DESCRIPTION("UP Board LED driver");
125MODULE_LICENSE("GPL");
126MODULE_ALIAS("platform:upboard-leds");