led_strip.h

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/*
 * Copyright (c) 2017 Linaro Limited
 * Copyright (c) 2024 Jamie McCrae
 *
 * SPDX-License-Identifier: Apache-2.0
 */

 
#ifndef ZEPHYR_INCLUDE_DRIVERS_LED_STRIP_H_
#define ZEPHYR_INCLUDE_DRIVERS_LED_STRIP_H_

 
#include <errno.h>
#include <zephyr/types.h>
#include <zephyr/device.h>
 
#ifdef __cplusplus
extern "C" {
#endif

struct led_rgb {
#ifdef CONFIG_LED_STRIP_RGB_SCRATCH
        /*
         * Pad/scratch space needed by some drivers. Users should
         * ignore.
         */
        uint8_t scratch;
#endif
        uint8_t r;
        uint8_t g;
        uint8_t b;
};

typedef int (*led_api_update_rgb)(const struct device *dev,
                                  struct led_rgb *pixels,
                                  size_t num_pixels);

typedef int (*led_api_update_channels)(const struct device *dev,
                                       uint8_t *channels,
                                       size_t num_channels);

typedef size_t (*led_api_length)(const struct device *dev);

__subsystem struct led_strip_driver_api {
        led_api_update_rgb update_rgb;
        led_api_update_channels update_channels;
        led_api_length length;
};

static inline int led_strip_update_rgb(const struct device *dev,
                                       struct led_rgb *pixels,
                                       size_t num_pixels)
{
        const struct led_strip_driver_api *api =
                (const struct led_strip_driver_api *)dev->api;
 
        /* Allow for out-of-tree drivers that do not have this function for 2 Zephyr releases
         * until making it mandatory, function added after Zephyr 3.6
         */
        if (api->length != NULL) {
                /* Ensure supplied pixel size is valid for this device */
                if (api->length(dev) < num_pixels) {
                        return -ERANGE;
                }
        }
 
        return api->update_rgb(dev, pixels, num_pixels);
}

static inline int led_strip_update_channels(const struct device *dev,
                                            uint8_t *channels,
                                            size_t num_channels)
{
        const struct led_strip_driver_api *api =
                (const struct led_strip_driver_api *)dev->api;
 
        if (api->update_channels == NULL) {
                return -ENOSYS;
        }
 
        return api->update_channels(dev, channels, num_channels);
}

static inline size_t led_strip_length(const struct device *dev)
{
        const struct led_strip_driver_api *api =
                (const struct led_strip_driver_api *)dev->api;
 
        return api->length(dev);
}
 
#ifdef __cplusplus
}
#endif

 
#endif  /* ZEPHYR_INCLUDE_DRIVERS_LED_STRIP_H_ */