ea2431f32f
tx_bufs/tx_count and rx_bufs/rx_count can be hold in another dedicated structure, thus reducing the number of parameters to transceive. This permits to avoid using the stack when calling transceive. Since we saved parameters, we can expose back the struct device pointer, to stay consistent with other device driver APIs. Fixes #5839 Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
106 lines
2.3 KiB
C
106 lines
2.3 KiB
C
/*
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* Copyright (c) 2018 Google LLC.
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <errno.h>
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#include <led_strip.h>
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#include <spi.h>
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struct apa102_data {
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struct device *spi;
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struct spi_config cfg;
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};
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static int apa102_update(struct device *dev, void *buf, size_t size)
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{
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struct apa102_data *data = dev->driver_data;
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static const u8_t zeros[] = {0, 0, 0, 0};
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static const u8_t ones[] = {0xFF, 0xFF, 0xFF, 0xFF};
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const struct spi_buf tx_bufs[] = {
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{
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/* Start frame: at least 32 zeros */
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.buf = (u8_t *)zeros,
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.len = sizeof(zeros),
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},
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{
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/* LED data itself */
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.buf = buf,
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.len = size,
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},
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{
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/* End frame: at least 32 ones to clock the
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* remaining bits to the LEDs at the end of
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* the strip.
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*/
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.buf = (u8_t *)ones,
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.len = sizeof(ones),
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},
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};
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const struct spi_buf_set tx = {
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.buffers = tx_bufs,
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.count = ARRAY_SIZE(tx)
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};
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return spi_write(data->spi, &data->cfg, &tx);
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}
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static int apa102_update_rgb(struct device *dev, struct led_rgb *pixels,
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size_t count)
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{
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u8_t *p = (u8_t *)pixels;
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size_t i;
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/* SOF (3 bits) followed by the 0 to 31 global dimming level */
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u8_t prefix = 0xE0 | 31;
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/* Rewrite to the on-wire format */
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for (i = 0; i < count; i++) {
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u8_t r = pixels[i].r;
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u8_t g = pixels[i].g;
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u8_t b = pixels[i].b;
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*p++ = prefix;
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*p++ = b;
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*p++ = g;
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*p++ = r;
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}
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BUILD_ASSERT(sizeof(struct led_rgb) == 4);
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return apa102_update(dev, pixels, sizeof(struct led_rgb) * count);
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}
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static int apa102_update_channels(struct device *dev, u8_t *channels,
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size_t num_channels)
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{
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/* Not implemented */
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return -EINVAL;
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}
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static int apa102_init(struct device *dev)
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{
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struct apa102_data *data = dev->driver_data;
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data->spi = device_get_binding(CONFIG_APA102_STRIP_BUS_NAME);
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if (!data->spi) {
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return -ENODEV;
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}
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data->cfg.frequency = CONFIG_APA102_STRIP_FREQUENCY;
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data->cfg.operation =
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SPI_OP_MODE_MASTER | SPI_TRANSFER_MSB | SPI_WORD_SET(8);
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return 0;
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}
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static struct apa102_data apa102_data_0;
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static const struct led_strip_driver_api apa102_api = {
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.update_rgb = apa102_update_rgb,
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.update_channels = apa102_update_channels,
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};
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DEVICE_AND_API_INIT(apa102_0, CONFIG_APA102_STRIP_NAME, apa102_init,
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&apa102_data_0, NULL, POST_KERNEL,
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CONFIG_LED_STRIP_INIT_PRIORITY, &apa102_api);
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