First shot at SPI interface

CMakeLists.txt

@@ -14,11 +14,13 @@ set(sources
 	src/udpproto.c
 	src/utils.c
 	src/sk6812.c
+	src/hat_spi.c
 	src/fader.h
 	src/logger.h
 	src/udpproto.h
 	src/utils.h
 	src/sk6812.h
+	src/hat_spi.h
 	)
 
 include_directories(

src/hat_spi.c

@@ -0,0 +1,129 @@
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <linux/spi/spidev.h>
+
+#include <stdint.h>
+#include <errno.h>
+#include <string.h>
+
+#include "logger.h"
+
+#include "hat_spi.h"
+
+static const char    *spi_dev   = "/dev/spidev0.0";
+static const uint32_t spi_speed = 12000000; // clock freq in Hz
+static const uint16_t spi_delay = 0; // us
+static const uint8_t  spi_bits  = 8; // bits per word
+
+int hat_spi_init(struct hat_spi_ctx *ctx)
+{
+	// Initialize SPI
+	uint8_t spi_mode = 0;
+
+	ctx->spidev_fd = open(spi_dev, O_RDWR);
+	if(ctx->spidev_fd < 0) {
+		LOG(LVL_ERR, "hat_spi: cannot open %s: %s", spi_dev, strerror(errno));
+		return -1;
+	}
+
+	if(ioctl(ctx->spidev_fd, SPI_IOC_WR_MODE, &spi_mode) == -1) {
+		LOG(LVL_ERR, "hat_spi: cannot change SPI mode: %s", strerror(errno));
+		return -1;
+	}
+
+	if(ioctl(ctx->spidev_fd, SPI_IOC_WR_BITS_PER_WORD, &spi_bits) == -1) {
+		LOG(LVL_ERR, "hat_spi: cannot change SPI bits per word: %s", strerror(errno));
+		return -1;
+	}
+
+	if(ioctl(ctx->spidev_fd, SPI_IOC_WR_MAX_SPEED_HZ, &spi_speed) == -1) {
+		LOG(LVL_ERR, "hat_spi: cannot change SPI speed: %s", strerror(errno));
+		return -1;
+	}
+
+	return 0;
+}
+
+int hat_spi_set_data(struct hat_spi_ctx *ctx, uint8_t strip, size_t len, uint8_t *data)
+{
+	uint8_t message[4 + len];
+
+	message[0] = 0x02; // cmd
+	message[1] = strip; // buffer index
+	message[2] = 0x00;  // start offset (LSB)
+	message[3] = 0x00;  // start offset (MSB)
+
+	memcpy(message + 4, data, len);
+
+	struct spi_ioc_transfer tr = {
+		.tx_buf = (unsigned long)message,
+		.rx_buf = (unsigned long)NULL,
+		.len = sizeof(message),
+		.delay_usecs = spi_delay,
+		.speed_hz = spi_speed,
+		.bits_per_word = 8
+	};
+
+	int ret;
+	if((ret = ioctl(ctx->spidev_fd, SPI_IOC_MESSAGE(1), &tr)) < 0) {
+		LOG(LVL_ERR, "ws2801: set_data: could not send SPI message: %s", strerror(errno));
+	}
+
+	return ret;
+}
+
+int hat_spi_flush(struct hat_spi_ctx *ctx)
+{
+	uint8_t message[1];
+
+	message[0] = 0x80; // cmd
+
+	struct spi_ioc_transfer tr = {
+		.tx_buf = (unsigned long)message,
+		.rx_buf = (unsigned long)NULL,
+		.len = sizeof(message),
+		.delay_usecs = spi_delay,
+		.speed_hz = spi_speed,
+		.bits_per_word = 8
+	};
+
+	int ret;
+	if((ret = ioctl(ctx->spidev_fd, SPI_IOC_MESSAGE(1), &tr)) < 0) {
+		LOG(LVL_ERR, "ws2801: flush: could not send SPI message: %s", strerror(errno));
+	}
+
+	return ret;
+}
+
+int hat_spi_config(struct hat_spi_ctx *ctx, uint16_t data_len)
+{
+	uint8_t message[3];
+
+	message[0] = 0x01; // cmd
+	message[1] = data_len & 0xFF; // bytes per strip (LSB)
+	message[2] = (data_len >> 8) & 0xFF; // bytes per strip (MSB)
+
+	struct spi_ioc_transfer tr = {
+		.tx_buf = (unsigned long)message,
+		.rx_buf = (unsigned long)NULL,
+		.len = sizeof(message),
+		.delay_usecs = spi_delay,
+		.speed_hz = spi_speed,
+		.bits_per_word = 8
+	};
+
+	int ret;
+	if((ret = ioctl(ctx->spidev_fd, SPI_IOC_MESSAGE(1), &tr)) < 0) {
+		LOG(LVL_ERR, "ws2801: flush: could not send SPI message: %s", strerror(errno));
+	}
+
+	return ret;
+}
+
+void hat_spi_shutdown(struct hat_spi_ctx *ctx)
+{
+	close(ctx->spidev_fd);
+}
+

src/hat_spi.h

@@ -0,0 +1,14 @@
+#ifndef HAT_SPI_H
+#define HAT_SPI_H
+
+struct hat_spi_ctx {
+	int spidev_fd;
+};
+
+int hat_spi_init(struct hat_spi_ctx *ctx);
+int hat_spi_set_data(struct hat_spi_ctx *ctx, uint8_t strip, size_t len, uint8_t *data);
+int hat_spi_flush(struct hat_spi_ctx *ctx);
+int hat_spi_config(struct hat_spi_ctx *ctx, uint16_t data_len);
+void hat_spi_shutdown(struct hat_spi_ctx *ctx);
+
+#endif // HAT_SPI_H

src/main.c

@@ -11,6 +11,7 @@
 #include "logger.h"
 #include "fader.h"
 #include "udpproto.h"
+#include "hat_spi.h"
 #include "utils.h"
 
 #define PORT 2703
@@ -23,8 +24,6 @@
 
 struct CmdLineArgs {
 	uint16_t port;
-	void    *base_addr;
-	uint32_t gpio_idx;
 	uint32_t num_modules;
 };
 
@@ -52,15 +51,6 @@ int parse_args(int argc, char **argv, struct CmdLineArgs *args)
 				args->port = (uint16_t)tmp_ul;
 				break;
 
-			case 'a': // base address
-				tmp_ull = strtoull(optarg, NULL, 0);
-				args->base_addr = (void*)tmp_ull;
-				break;
-
-			case 'g': // gpio
-				args->gpio_idx = strtoul(optarg, NULL, 0);
-				break;
-
 			case 'n': // number of modules
 				args->num_modules = strtoul(optarg, NULL, 0);
 				break;
@@ -77,6 +67,7 @@ int main(int argc, char **argv)
 {
 	struct sk6812_ctx ctx;
 	struct fader_ctx fader_ctx;
+	struct hat_spi_ctx hat_ctx;
 
 	struct CmdLineArgs args;
 
@@ -87,8 +78,6 @@ int main(int argc, char **argv)
 
 	// default arguments
 	args.port = PORT;
-	args.base_addr = BASE_ADDR;
-	args.gpio_idx = GPIO_IDX;
 	args.num_modules = NUM_MODULES;
 
 	// parse command line arguments
@@ -98,8 +87,19 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	// initialize ws2801 library
+	// initialize SPI interface for hat
-	if(sk6812_init(&ctx, GPIO_IDX, BASE_ADDR, NUM_MODULES) == -1) {
+	if(hat_spi_init(&hat_ctx) == -1) {
+		LOG(LVL_FATAL, "Could not initialize SPI interface.");
+		return 1;
+	}
+
+	if(hat_spi_config(&hat_ctx, NUM_MODULES*4) == -1) {
+		LOG(LVL_FATAL, "Could not configure LED driver hat.");
+		return 1;
+	}
+
+	// initialize sk6812 library
+	if(sk6812_init(&ctx, &hat_ctx, 0, NUM_MODULES) == -1) {
 		LOG(LVL_FATAL, "Could not initialize SK6812 library.");
 		return 1;
 	}

src/sk6812.c

@@ -1,124 +1,42 @@
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <sys/mman.h>
-#include <errno.h>
-
-#include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
+#include <stdint.h>
 
 #include "logger.h"
+#include "hat_spi.h"
+
 #include "sk6812.h"
 
-int sk6812_init(struct sk6812_ctx *ctx, uint32_t gpio_idx, void *phys_baseptr, uint32_t num_modules)
+int sk6812_init(struct sk6812_ctx *ctx, struct hat_spi_ctx *hat_ctx, uint8_t strip_id, uint32_t num_modules)
 {
-	ctx->gpio_idx = gpio_idx;
+	ctx->hat_ctx = hat_ctx;
+	ctx->num_modules = num_modules;
+	ctx->strip_id = strip_id;
 
-	/*
+	ctx->pixeldata = malloc(4*num_modules * sizeof(ctx->pixeldata[0]));
-	 * Setup memory map for LED memory.
+	if(!ctx->pixeldata) {
-	 */
+		LOG(LVL_ERR, "sk6812: malloc for pixeldata failed.");
-	size_t mapsize = num_modules*sizeof(uint32_t);
-	size_t pagesize = (size_t)getpagesize();
-
-	if((mapsize % pagesize) != 0) {
-		mapsize = pagesize * (mapsize / pagesize + 1);
-	}
-
-	ctx->devmem_fd = open("/dev/mem", O_RDWR|O_SYNC);
-	if(ctx->devmem_fd == -1) {
-		LOG(LVL_ERR, "sk6812: open(/dev/mem) failed: %s.", strerror(errno));
 		return -1;
 	}
 
-	ctx->memptr = (struct sk6812_memory*)mmap(0, mapsize, PROT_READ|PROT_WRITE, MAP_SHARED, ctx->devmem_fd, (off_t)phys_baseptr);
-	if(ctx->memptr == MAP_FAILED) {
-		LOG(LVL_ERR, "sk6812: mmap(0x%08X) failed: %s.", phys_baseptr, strerror(errno));
-		close(ctx->devmem_fd);
-		return -1;
-	}
-
-	ctx->mapped_size = mapsize;
-
-	// write number of modules to mapped memory
-	ctx->memptr->num_leds = num_modules;
-
-	/*
-	 * set up GPIO
-	 */
-	char filename[256];
-	char data[32];
-	int dlen;
-
-	int fd = open("/sys/class/gpio/export", O_WRONLY);
-	if(ctx->devmem_fd == -1) {
-		LOG(LVL_ERR, "sk6812: open(/sys/class/gpio/export, WRONLY) failed: %s.", strerror(errno));
-		return -1;
-	}
-
-	dlen = snprintf(data, 32, "%d\n", ctx->gpio_idx);
-	write(fd, data, dlen);
-	close(fd);
-
-	snprintf(filename, 256, "/sys/class/gpio/gpio%u/direction", ctx->gpio_idx);
-
-	fd = open(filename, O_WRONLY);
-	if(ctx->devmem_fd == -1) {
-		LOG(LVL_ERR, "sk6812: open(%s, WRONLY) failed: %s.", filename, strerror(errno));
-		return -1;
-	}
-
-	write(fd, "out\n", 4);
-	close(fd);
-
 	return 0;
 }
 
 void sk6812_shutdown(struct sk6812_ctx *ctx)
 {
-	munmap(ctx->memptr, ctx->mapped_size);
+	free(ctx->pixeldata);
-	close(ctx->devmem_fd);
 }
 
 void sk6812_set_colour(struct sk6812_ctx *ctx, uint32_t module, uint8_t red, uint8_t green, uint8_t blue, uint8_t white)
 {
 	// despite the info in the datasheet, red and green are swapped :/
-	uint32_t value =
+	ctx->pixeldata[4*module + 0] = green;
-		((uint32_t)green << 24U) |
+	ctx->pixeldata[4*module + 1] = red;
-		((uint32_t)red << 16U) |
+	ctx->pixeldata[4*module + 2] = blue;
-		((uint32_t)blue << 8U) |
+	ctx->pixeldata[4*module + 3] = white;
-		(uint32_t)white;
-
-	ctx->memptr->led_data[module] = value;
 }
 
 int sk6812_send_update(struct sk6812_ctx *ctx)
 {
-	LOG(LVL_DEBUG, "Updating with LED count: %u", ctx->memptr->num_leds);
+	return hat_spi_set_data(ctx->hat_ctx, ctx->strip_id, ctx->num_modules*4, ctx->pixeldata);
-
-	char filename[256];
-
-	snprintf(filename, 256, "/sys/class/gpio/gpio%u/value", ctx->gpio_idx);
-
-	int fd = open(filename, O_WRONLY);
-	if(ctx->devmem_fd == -1) {
-		LOG(LVL_ERR, "sk6812: open(%s, WRONLY) failed: %s.", filename, strerror(errno));
-		return -1;
-	}
-
-	write(fd, "0\n", 2);
-	close(fd);
-
-	fd = open(filename, O_WRONLY);
-	if(ctx->devmem_fd == -1) {
-		LOG(LVL_ERR, "sk6812: open(%s, WRONLY) failed: %s.", filename, strerror(errno));
-		return -1;
-	}
-
-	write(fd, "1\n", 2);
-	close(fd);
-
-	return 0;
 }
 

src/sk6812.h

@@ -3,6 +3,8 @@
 
 #include <stdint.h>
 
+struct hat_spi_ctx;
+
 struct sk6812_memory
 {
 	uint32_t num_leds;
@@ -11,14 +13,14 @@ struct sk6812_memory
 
 struct sk6812_ctx
 {
-	struct sk6812_memory *memptr;
+	uint8_t *pixeldata;
-	char *gpio_value_path;
+	uint32_t num_modules;
-	int devmem_fd;
+	uint8_t strip_id;
-	size_t mapped_size;
+
-	uint32_t gpio_idx;
+	struct hat_spi_ctx *hat_ctx;
 };
 
-int sk6812_init(struct sk6812_ctx *ctx, uint32_t gpio_idx, void *phys_baseptr, uint32_t num_modules);
+int sk6812_init(struct sk6812_ctx *ctx, struct hat_spi_ctx *hat_ctx, uint8_t strip_id, uint32_t num_modules);
 void sk6812_shutdown(struct sk6812_ctx *ctx);
 void sk6812_set_colour(struct sk6812_ctx *ctx, uint32_t module, uint8_t red, uint8_t green, uint8_t blue, uint8_t white);
 int sk6812_send_update(struct sk6812_ctx *ctx);