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authorJoel Challis <git@zvecr.com>2019-12-31 17:26:40 +0000
committerGitHub <noreply@github.com>2019-12-31 17:26:40 +0000
commit680ebef0869b7860017a80bd601faac61227cd28 (patch)
tree4915395331bac5952a17d9e8a2912433f4c5b916
parent7ba6456c0b2e041bb9f97dbed265c5b8b4b12192 (diff)
SPI DMA based RGB Underglow for STM32 (#7674)
* Initial stash of ws2812 spi driver * Update comment, add sync backup plan * Add testing notes to spi ws2812 driver * Align RGBW error messages
-rw-r--r--docs/ws2812_driver.md29
-rw-r--r--drivers/arm/ws2812_spi.c91
2 files changed, 118 insertions, 2 deletions
diff --git a/docs/ws2812_driver.md b/docs/ws2812_driver.md
index 67481c458d..80b6948586 100644
--- a/docs/ws2812_driver.md
+++ b/docs/ws2812_driver.md
@@ -14,7 +14,7 @@ These LEDs are called "addressable" because instead of using a wire per color, e
|----------|--------------------|--------------------|
| bit bang | :heavy_check_mark: | :heavy_check_mark: |
| I2C | :heavy_check_mark: | |
-| SPI | | Soon™ |
+| SPI | | :heavy_check_mark: |
| PWM | | Soon™ |
## Driver configuration
@@ -40,3 +40,30 @@ Configure the hardware via your config.h:
#define WS2812_ADDRESS 0xb0 // default: 0xb0
#define WS2812_TIMEOUT 100 // default: 100
```
+
+### SPI
+Targeting STM32 boards where WS2812 support is offloaded to an SPI hardware device. The advantage is that the use of DMA offloads processing of the WS2812 protocol from the MCU. `RGB_DI_PIN` for this driver is the configured SPI MOSI pin. Due to the nature of repurposing SPI to drive the LEDs, the other SPI pins, MISO and SCK, **must** remain unused. To configure it, add this to your rules.mk:
+
+```make
+WS2812_DRIVER = spi
+```
+
+Configure the hardware via your config.h:
+```c
+#define WS2812_SPI SPID1 // default: SPID1
+#define WS2812_SPI_MOSI_PAL_MODE 5 // Pin "alternate function", see the respective datasheet for the appropriate values for your MCU. default: 5
+```
+
+You must also turn on the SPI feature in your halconf.h and mcuconf.h
+
+#### Testing Notes
+
+While not an exhaustive list, the following table provides the scenarios that have been partially validated:
+
+| | SPI1 | SPI2 | SPI3 |
+|-|-|-|-|
+| f072 | ? | B15 :heavy_check_mark: | N/A |
+| f103 | A7 :heavy_check_mark: | B15 :heavy_check_mark: | N/A |
+| f303 | A7 :heavy_check_mark: B5 :heavy_check_mark: | B15 :heavy_check_mark: | B5 :heavy_check_mark: |
+
+*Other supported ChibiOS boards and/or pins may function, it will be highly chip and configuration dependent.* \ No newline at end of file
diff --git a/drivers/arm/ws2812_spi.c b/drivers/arm/ws2812_spi.c
index 2094e50098..0e954ec506 100644
--- a/drivers/arm/ws2812_spi.c
+++ b/drivers/arm/ws2812_spi.c
@@ -1 +1,90 @@
-#error("NOT SUPPORTED") \ No newline at end of file
+#include "quantum.h"
+#include "ws2812.h"
+
+/* Adapted from https://github.com/gamazeps/ws2812b-chibios-SPIDMA/ */
+
+#ifdef RGBW
+# error "RGBW not supported"
+#endif
+
+// Define the spi your LEDs are plugged to here
+#ifndef WS2812_SPI
+# define WS2812_SPI SPID1
+#endif
+
+#ifndef WS2812_SPI_MOSI_PAL_MODE
+# define WS2812_SPI_MOSI_PAL_MODE 5
+#endif
+
+#define BYTES_FOR_LED_BYTE 4
+#define NB_COLORS 3
+#define BYTES_FOR_LED (BYTES_FOR_LED_BYTE * NB_COLORS)
+#define DATA_SIZE (BYTES_FOR_LED * RGBLED_NUM)
+#define RESET_SIZE 200
+#define PREAMBLE_SIZE 4
+
+static uint8_t txbuf[PREAMBLE_SIZE + DATA_SIZE + RESET_SIZE] = {0};
+
+/*
+ * As the trick here is to use the SPI to send a huge pattern of 0 and 1 to
+ * the ws2812b protocol, we use this helper function to translate bytes into
+ * 0s and 1s for the LED (with the appropriate timing).
+ */
+static uint8_t get_protocol_eq(uint8_t data, int pos) {
+ uint8_t eq = 0;
+ if (data & (1 << (2 * (3 - pos))))
+ eq = 0b1110;
+ else
+ eq = 0b1000;
+ if (data & (2 << (2 * (3 - pos))))
+ eq += 0b11100000;
+ else
+ eq += 0b10000000;
+ return eq;
+}
+
+static void set_led_color_rgb(LED_TYPE color, int pos) {
+ uint8_t* tx_start = &txbuf[PREAMBLE_SIZE];
+
+ for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + j] = get_protocol_eq(color.g, j);
+ for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE + j] = get_protocol_eq(color.r, j);
+ for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE * 2 + j] = get_protocol_eq(color.b, j);
+}
+
+void ws2812_init(void) {
+#if defined(USE_GPIOV1)
+ palSetLineMode(RGB_DI_PIN, PAL_MODE_STM32_ALTERNATE_PUSHPULL);
+#else
+ palSetLineMode(RGB_DI_PIN, PAL_MODE_ALTERNATE(WS2812_SPI_MOSI_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL);
+#endif
+
+ // TODO: more dynamic baudrate
+ static const SPIConfig spicfg = {
+ NULL, PAL_PORT(RGB_DI_PIN), PAL_PAD(RGB_DI_PIN),
+ SPI_CR1_BR_1 | SPI_CR1_BR_0 // baudrate : fpclk / 8 => 1tick is 0.32us (2.25 MHz)
+ };
+
+ spiAcquireBus(&WS2812_SPI); /* Acquire ownership of the bus. */
+ spiStart(&WS2812_SPI, &spicfg); /* Setup transfer parameters. */
+ spiSelect(&WS2812_SPI); /* Slave Select assertion. */
+}
+
+void ws2812_setleds(LED_TYPE* ledarray, uint16_t leds) {
+ static bool s_init = false;
+ if (!s_init) {
+ ws2812_init();
+ s_init = true;
+ }
+
+ for (uint8_t i = 0; i < leds; i++) {
+ set_led_color_rgb(ledarray[i], i);
+ }
+
+ // Send async - each led takes ~0.03ms, 50 leds ~1.5ms, animations flushing faster than send will cause issues.
+ // Instead spiSend can be used to send synchronously (or the thread logic can be added back).
+#ifdef WS2812_SPI_SYNC
+ spiSend(&WS2812_SPI, sizeof(txbuf) / sizeof(txbuf[0]), txbuf);
+#else
+ spiStartSend(&WS2812_SPI, sizeof(txbuf) / sizeof(txbuf[0]), txbuf);
+#endif
+}