zephyr/drivers/led_strip/tlc5971.c

362 lines
12 KiB
C

/*
* Copyright (c) 2022 Esco Medical ApS
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT ti_tlc5971
#include <zephyr/kernel.h>
#include <zephyr/drivers/spi.h>
#include <zephyr/drivers/led_strip.h>
#include <zephyr/drivers/led_strip/tlc5971.h>
#include <zephyr/dt-bindings/led/led.h>
#include <zephyr/sys/util.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(tlc5971, CONFIG_LED_STRIP_LOG_LEVEL);
struct tlc5971_config {
struct spi_dt_spec bus;
const uint8_t *color_mapping;
uint8_t num_pixels;
uint8_t num_colors;
};
struct tlc5971_data {
uint8_t *data_buffer;
uint8_t gbc_color_1;
uint8_t gbc_color_2;
uint8_t gbc_color_3;
uint8_t control_data;
};
/** SPI operation word constant, SPI mode 0, CPOL = 0, CPHA = 0 */
#define TLC5971_SPI_OPERATION (SPI_OP_MODE_MASTER | SPI_TRANSFER_MSB | SPI_WORD_SET(8))
/** Number of supported colors */
#define TLC5971_NUMBER_OF_COLORS 3
/**
* @brief Number of RGB pixels per TLC5791 device
*
* The TLC5971 has 4x RGB outputs per device, where each RGB group constitues a pixel from this
* drivers point of view.
*/
#define TLC5971_PIXELS_PER_DEVICE 4
/** Length in bytes of data packet per TLC5791 device */
#define TLC5971_PACKET_LEN 28
/** write command for writing control data and GS data to internal registers */
#define TLC5971_WRITE_COMMAND 0x25
/** GS reference clock select bit in FC data (0 = internal oscillator clock, 1 = SCKI clock). */
#define TLC5971_BYTE27_CTRL_BIT_EXTGCK BIT(0)
/** GS reference clock edge select bit for OUTXn on-off timing control in FC data */
#define TLC5971_BYTE27_CTRL_BIT_OUTTMG BIT(1)
/** Constant-current output enable bit in FC data (0 = output control enabled, 1 = blank). */
#define TLC5971_BYTE26_CTRL_BIT_BLANK BIT(5)
/** Auto display repeat mode enable bit in FC data (0 = disabled, 1 = enabled). */
#define TLC5971_BYTE26_CTRL_BIT_DSPRPT BIT(6)
/** Display timing reset mode enable bit in FC data (0 = disabled, 1 = enabled). */
#define TLC5971_BYTE26_CTRL_BIT_TMGRST BIT(7)
/** Bit mask for write cmd in data byte 27 */
#define TLC5971_BYTE27_WRITE_CMD_MASK GENMASK(7, 2)
/** Bit mask for control bits in data byte 27 */
#define TLC5971_BYTE27_CTRL_MASK GENMASK(1, 0)
/** Bit mask for control bits in data byte 26 */
#define TLC5971_BYTE26_CTRL_MASK GENMASK(7, 5)
/** Bit mask for global brightness control for color 1 in data byte 26, upper 5 bits of GBC */
#define TLC5971_BYTE26_GBC1_MASK GENMASK(4, 0)
/** Bit mask for global brightness control for color 1 in data byte 25, lower 2 bits of GBC */
#define TLC5971_BYTE25_GBC1_MASK GENMASK(7, 6)
/** Bit mask for global brightness control for color 2 in data byte 25, upper 6 bits of GBC */
#define TLC5971_BYTE25_GBC2_MASK GENMASK(5, 0)
/** Bit mask for global brightness control for color 2 in data byte 24, lower 1 bits of GBC */
#define TLC5971_BYTE24_GBC2_MASK BIT(7)
/** Bit mask for global brightness control for color 3 in data byte 24, all 7 bits of GBC */
#define TLC5971_BYTE24_GBC3_MASK GENMASK(6, 0)
/**
* @brief create data byte 27 from control data
*
* @param control_data control bits
* @return uint8_t the serialized data byte 27
*/
static inline uint8_t tlc5971_data_byte27(uint8_t control_data)
{
return FIELD_PREP(TLC5971_BYTE27_WRITE_CMD_MASK, TLC5971_WRITE_COMMAND) |
FIELD_PREP(TLC5971_BYTE27_CTRL_MASK, control_data);
}
/**
* @brief create data byte 26 from control data and color 1 GBC
*
* @param control_data control bits
* @param gbc_color_1 global brightness control for color 1 LEDs
* @return uint8_t the serialized data byte 26
*/
static inline uint8_t tlc5971_data_byte26(uint8_t control_data, uint8_t gbc_color_1)
{
return FIELD_PREP(TLC5971_BYTE26_CTRL_MASK, control_data) |
FIELD_PREP(TLC5971_BYTE26_GBC1_MASK, (gbc_color_1 >> 2));
}
/**
* @brief create data byte 25 from color 1 and 2 GBC
*
* @param gbc_color_1 global brightness control for color 1 LEDs
* @param gbc_color_2 global brightness control for color 2 LEDs
* @return uint8_t the serialized data byte 25
*/
static inline uint8_t tlc5971_data_byte25(uint8_t gbc_color_1, uint8_t gbc_color_2)
{
return FIELD_PREP(TLC5971_BYTE25_GBC1_MASK, gbc_color_1) |
FIELD_PREP(TLC5971_BYTE25_GBC2_MASK, (gbc_color_2 >> 1));
}
/**
* @brief create data byte 24 from color 2 and 3 GBC
*
* @param gbc_color_2 global brightness control for color 2 LEDs
* @param gbc_color_3 global brightness control for color 3 LEDs
* @return uint8_t the serialized data byte 24
*/
static inline uint8_t tlc5971_data_byte24(uint8_t gbc_color_2, uint8_t gbc_color_3)
{
return FIELD_PREP(TLC5971_BYTE24_GBC2_MASK, gbc_color_2) |
FIELD_PREP(TLC5971_BYTE24_GBC3_MASK, gbc_color_3);
}
/**
* @brief map user colors to tlc5971 color order
*
* @param color_id color id from color mapping
* @param pixel_data rgb data to be mapped
* @return the mapped color value
*/
static uint8_t tlc5971_map_color(int color_id, const struct led_rgb *pixel_data)
{
uint8_t temp = 0;
switch (color_id) {
case LED_COLOR_ID_RED:
temp = pixel_data->r;
break;
case LED_COLOR_ID_GREEN:
temp = pixel_data->g;
break;
case LED_COLOR_ID_BLUE:
temp = pixel_data->b;
break;
default:
temp = 0;
break;
}
return temp;
}
/**
* @brief serialize control data and pixel data for device daisy chain
*
* the serializer only supports "full" devices, meaning each device is expected
* to be mounted with all 4 LEDs.
*
* @param dev device pointer
* @param pixels pixel RGB data for daisy chain
* @param num_pixels number of pixels in daisy chain
*/
static void tlc5971_fill_data_buffer(const struct device *dev, struct led_rgb *pixels,
size_t num_pixels)
{
const struct tlc5971_config *cfg = dev->config;
struct tlc5971_data *data = dev->data;
uint8_t *data_buffer = data->data_buffer;
int count = 0;
/*
* tlc5971 device order is reversed as the rgb data for the last device in the daisy chain
* should be transmitted first.
*/
for (int device = (num_pixels / TLC5971_PIXELS_PER_DEVICE) - 1; device >= 0; device--) {
/*
* The SPI frame format expects a BGR color order for the global brightness control
* values, but since the led_strip API allows custom color mappings, we simply use
* color_x terms to keep things generic.
*/
data_buffer[count++] = tlc5971_data_byte27(data->control_data);
data_buffer[count++] = tlc5971_data_byte26(data->control_data, data->gbc_color_1);
data_buffer[count++] = tlc5971_data_byte25(data->gbc_color_1, data->gbc_color_2);
data_buffer[count++] = tlc5971_data_byte24(data->gbc_color_2, data->gbc_color_3);
for (int pixel = (TLC5971_PIXELS_PER_DEVICE - 1); pixel >= 0; pixel--) {
/* data is "reversed" so RGB0 comes last, i.e at byte 0 */
const struct led_rgb *pixel_data =
&pixels[(device * TLC5971_PIXELS_PER_DEVICE) + pixel];
/*
* Convert pixel data into SPI frames, mapping user colors to tlc5971
* data frame color order (BGR).
*/
for (int color = 0; color < cfg->num_colors; color++) {
uint8_t temp =
tlc5971_map_color(cfg->color_mapping[color], pixel_data);
/*
* The tlc5971 rgb values are 16 bit but zephyr's rgb values are
* 8 bit. Simply upscale to 16 bit by using the 8 bit value for both
* LSB and MSB of the 16 bit word.
*/
data_buffer[count++] = temp;
data_buffer[count++] = temp;
}
}
}
}
static int tlc5971_transmit_data(const struct device *dev, size_t num_pixels)
{
const struct tlc5971_config *cfg = dev->config;
struct tlc5971_data *data = dev->data;
struct spi_buf buf = {
.buf = data->data_buffer,
.len = (num_pixels / TLC5971_PIXELS_PER_DEVICE) * TLC5971_PACKET_LEN,
};
const struct spi_buf_set tx = {
.buffers = &buf,
.count = 1,
};
return spi_write_dt(&cfg->bus, &tx);
}
static int tlc5971_update_rgb(const struct device *dev, struct led_rgb *pixels, size_t num_pixels)
{
const struct tlc5971_config *cfg = dev->config;
if (num_pixels > cfg->num_pixels) {
LOG_ERR("invalid number of pixels, %zu vs actual %i", num_pixels, cfg->num_pixels);
return -EINVAL;
}
tlc5971_fill_data_buffer(dev, pixels, num_pixels);
return tlc5971_transmit_data(dev, num_pixels);
}
static int tlc5971_update_channels(const struct device *dev, uint8_t *channels, size_t num_channels)
{
ARG_UNUSED(dev);
ARG_UNUSED(channels);
ARG_UNUSED(num_channels);
return -ENOTSUP;
}
int tlc5971_set_global_brightness(const struct device *dev, struct led_rgb pixel)
{
const struct tlc5971_config *cfg = dev->config;
struct tlc5971_data *data = dev->data;
int res = -EINVAL;
if ((pixel.r <= TLC5971_GLOBAL_BRIGHTNESS_CONTROL_MAX) &&
(pixel.g <= TLC5971_GLOBAL_BRIGHTNESS_CONTROL_MAX) &&
(pixel.b <= TLC5971_GLOBAL_BRIGHTNESS_CONTROL_MAX)) {
data->gbc_color_1 = tlc5971_map_color(cfg->color_mapping[0], &pixel);
data->gbc_color_2 = tlc5971_map_color(cfg->color_mapping[1], &pixel);
data->gbc_color_3 = tlc5971_map_color(cfg->color_mapping[2], &pixel);
res = 0;
}
return res;
}
static int tlc5971_init(const struct device *dev)
{
const struct tlc5971_config *cfg = dev->config;
struct tlc5971_data *data = dev->data;
if (!spi_is_ready_dt(&cfg->bus)) {
LOG_ERR("%s: SPI device %s not ready", dev->name, cfg->bus.bus->name);
return -ENODEV;
}
if ((cfg->num_pixels % TLC5971_PIXELS_PER_DEVICE) != 0) {
LOG_ERR("%s: chain length must be multiple of 4", dev->name);
return -EINVAL;
}
if (cfg->num_colors != TLC5971_NUMBER_OF_COLORS) {
LOG_ERR("%s: the tlc5971 only supports %i colors", dev->name,
TLC5971_NUMBER_OF_COLORS);
return -EINVAL;
}
for (int i = 0; i < cfg->num_colors; i++) {
switch (cfg->color_mapping[i]) {
case LED_COLOR_ID_RED:
case LED_COLOR_ID_GREEN:
case LED_COLOR_ID_BLUE:
break;
default:
LOG_ERR("%s: invalid color mapping", dev->name);
return -EINVAL;
}
}
/*
* set up sane defaults for control data.
* unblanks leds, enables auto display repeat, enables timing resetm uses internal clock for
* PWM generation and sets the GS reference clock edge select to rising edge
*/
data->control_data = TLC5971_BYTE27_CTRL_BIT_OUTTMG | TLC5971_BYTE26_CTRL_BIT_DSPRPT |
TLC5971_BYTE26_CTRL_BIT_TMGRST;
return 0;
}
static const struct led_strip_driver_api tlc5971_api = {
.update_rgb = tlc5971_update_rgb,
.update_channels = tlc5971_update_channels,
};
#define TLC5971_DATA_BUFFER_LENGTH(inst) \
(DT_INST_PROP(inst, chain_length) / TLC5971_PIXELS_PER_DEVICE) * TLC5971_PACKET_LEN
#define TLC5971_DEVICE(inst) \
static const uint8_t tlc5971_##inst##_color_mapping[] = DT_INST_PROP(inst, color_mapping); \
static const struct tlc5971_config tlc5971_##inst##_config = { \
.bus = SPI_DT_SPEC_INST_GET(inst, TLC5971_SPI_OPERATION, 0), \
.num_pixels = DT_INST_PROP(inst, chain_length), \
.num_colors = DT_INST_PROP_LEN(inst, color_mapping), \
.color_mapping = tlc5971_##inst##_color_mapping, \
}; \
static uint8_t tlc5971_##inst##_data_buffer[TLC5971_DATA_BUFFER_LENGTH(inst)]; \
static struct tlc5971_data tlc5971_##inst##_data = { \
.data_buffer = tlc5971_##inst##_data_buffer, \
.gbc_color_1 = TLC5971_GLOBAL_BRIGHTNESS_CONTROL_MAX, \
.gbc_color_2 = TLC5971_GLOBAL_BRIGHTNESS_CONTROL_MAX, \
.gbc_color_3 = TLC5971_GLOBAL_BRIGHTNESS_CONTROL_MAX, \
}; \
DEVICE_DT_INST_DEFINE(inst, tlc5971_init, NULL, &tlc5971_##inst##_data, \
&tlc5971_##inst##_config, POST_KERNEL, \
CONFIG_LED_STRIP_INIT_PRIORITY, &tlc5971_api);
DT_INST_FOREACH_STATUS_OKAY(TLC5971_DEVICE)