blob: cea394d79018bee415dc470a89b544465442695e [file] [log] [blame] [edit]
/*
* Copyright (c) 2018 Google LLC.
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT apa_apa102
#include <errno.h>
#include <zephyr/drivers/led_strip.h>
#include <zephyr/drivers/spi.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/sys/util.h>
struct apa102_config {
struct spi_dt_spec bus;
};
static int apa102_update(const struct device *dev, void *buf, size_t size)
{
const struct apa102_config *config = dev->config;
static const uint8_t zeros[] = { 0, 0, 0, 0 };
static const uint8_t ones[] = { 0xFF, 0xFF, 0xFF, 0xFF };
const struct spi_buf tx_bufs[] = {
{
/* Start frame: at least 32 zeros */
.buf = (uint8_t *)zeros,
.len = sizeof(zeros),
},
{
/* LED data itself */
.buf = buf,
.len = size,
},
{
/* End frame: at least 32 ones to clock the
* remaining bits to the LEDs at the end of
* the strip.
*/
.buf = (uint8_t *)ones,
.len = sizeof(ones),
},
};
const struct spi_buf_set tx = {
.buffers = tx_bufs,
.count = ARRAY_SIZE(tx_bufs)
};
return spi_write_dt(&config->bus, &tx);
}
static int apa102_update_rgb(const struct device *dev, struct led_rgb *pixels,
size_t count)
{
uint8_t *p = (uint8_t *)pixels;
size_t i;
/* SOF (3 bits) followed by the 0 to 31 global dimming level */
uint8_t prefix = 0xE0 | 31;
/* Rewrite to the on-wire format */
for (i = 0; i < count; i++) {
uint8_t r = pixels[i].r;
uint8_t g = pixels[i].g;
uint8_t b = pixels[i].b;
*p++ = prefix;
*p++ = b;
*p++ = g;
*p++ = r;
}
BUILD_ASSERT(sizeof(struct led_rgb) == 4);
return apa102_update(dev, pixels, sizeof(struct led_rgb) * count);
}
static int apa102_update_channels(const struct device *dev, uint8_t *channels,
size_t num_channels)
{
/* Not implemented */
return -EINVAL;
}
static int apa102_init(const struct device *dev)
{
const struct apa102_config *config = dev->config;
if (!spi_is_ready_dt(&config->bus)) {
return -ENODEV;
}
return 0;
}
static const struct led_strip_driver_api apa102_api = {
.update_rgb = apa102_update_rgb,
.update_channels = apa102_update_channels,
};
#define APA102_DEVICE(idx) \
static const struct apa102_config apa102_##idx##_config = { \
.bus = SPI_DT_SPEC_INST_GET( \
idx, \
SPI_OP_MODE_MASTER | SPI_TRANSFER_MSB | SPI_WORD_SET(8), \
0), \
}; \
\
DEVICE_DT_INST_DEFINE(idx, \
apa102_init, \
NULL, \
NULL, \
&apa102_##idx##_config, \
POST_KERNEL, \
CONFIG_LED_STRIP_INIT_PRIORITY, \
&apa102_api);
DT_INST_FOREACH_STATUS_OKAY(APA102_DEVICE)