diff options
Diffstat (limited to 'drivers/chibios/ws2812_pwm.c')
| -rw-r--r-- | drivers/chibios/ws2812_pwm.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/chibios/ws2812_pwm.c b/drivers/chibios/ws2812_pwm.c new file mode 100644 index 0000000000..1a17210298 --- /dev/null +++ b/drivers/chibios/ws2812_pwm.c @@ -0,0 +1,207 @@ +#include "ws2812.h" +#include "quantum.h" +#include "hal.h" + +/* Adapted from https://github.com/joewa/WS2812-LED-Driver_ChibiOS/ */ + +#ifdef RGBW +# error "RGBW not supported" +#endif + +#ifndef WS2812_PWM_DRIVER +# define WS2812_PWM_DRIVER PWMD2 // TIMx +#endif +#ifndef WS2812_PWM_CHANNEL +# define WS2812_PWM_CHANNEL 2 // Channel +#endif +#ifndef WS2812_PWM_PAL_MODE +# define WS2812_PWM_PAL_MODE 2 // DI Pin's alternate function value +#endif +#ifndef WS2812_DMA_STREAM +# define WS2812_DMA_STREAM STM32_DMA1_STREAM2 // DMA Stream for TIMx_UP +#endif +#ifndef WS2812_DMA_CHANNEL +# define WS2812_DMA_CHANNEL 2 // DMA Channel for TIMx_UP +#endif + +#ifndef WS2812_PWM_TARGET_PERIOD +//# define WS2812_PWM_TARGET_PERIOD 800000 // Original code is 800k...? +# define WS2812_PWM_TARGET_PERIOD 80000 // TODO: work out why 10x less on f303/f4x1 +#endif + +/* --- PRIVATE CONSTANTS ---------------------------------------------------- */ + +#define WS2812_PWM_FREQUENCY (STM32_SYSCLK / 2) /**< Clock frequency of PWM, must be valid with respect to system clock! */ +#define WS2812_PWM_PERIOD (WS2812_PWM_FREQUENCY / WS2812_PWM_TARGET_PERIOD) /**< Clock period in ticks. 1 / 800kHz = 1.25 uS (as per datasheet) */ + +/** + * @brief Number of bit-periods to hold the data line low at the end of a frame + * + * The reset period for each frame must be at least 50 uS; so we add in 50 bit-times + * of zeroes at the end. (50 bits)*(1.25 uS/bit) = 62.5 uS, which gives us some + * slack in the timing requirements + */ +#define WS2812_RESET_BIT_N (50) +#define WS2812_COLOR_BIT_N (RGBLED_NUM * 24) /**< Number of data bits */ +#define WS2812_BIT_N (WS2812_COLOR_BIT_N + WS2812_RESET_BIT_N) /**< Total number of bits in a frame */ + +/** + * @brief High period for a zero, in ticks + * + * Per the datasheet: + * WS2812: + * - T0H: 200 nS to 500 nS, inclusive + * - T0L: 650 nS to 950 nS, inclusive + * WS2812B: + * - T0H: 200 nS to 500 nS, inclusive + * - T0L: 750 nS to 1050 nS, inclusive + * + * The duty cycle is calculated for a high period of 350 nS. + */ +#define WS2812_DUTYCYCLE_0 (WS2812_PWM_FREQUENCY / (1000000000 / 350)) + +/** + * @brief High period for a one, in ticks + * + * Per the datasheet: + * WS2812: + * - T1H: 550 nS to 850 nS, inclusive + * - T1L: 450 nS to 750 nS, inclusive + * WS2812B: + * - T1H: 750 nS to 1050 nS, inclusive + * - T1L: 200 nS to 500 nS, inclusive + * + * The duty cycle is calculated for a high period of 800 nS. + * This is in the middle of the specifications of the WS2812 and WS2812B. + */ +#define WS2812_DUTYCYCLE_1 (WS2812_PWM_FREQUENCY / (1000000000 / 800)) + +/* --- PRIVATE MACROS ------------------------------------------------------- */ + +/** + * @brief Determine the index in @ref ws2812_frame_buffer "the frame buffer" of a given bit + * + * @param[in] led: The led index [0, @ref RGBLED_NUM) + * @param[in] byte: The byte number [0, 2] + * @param[in] bit: The bit number [0, 7] + * + * @return The bit index + */ +#define WS2812_BIT(led, byte, bit) (24 * (led) + 8 * (byte) + (7 - (bit))) + +/** + * @brief Determine the index in @ref ws2812_frame_buffer "the frame buffer" of a given red bit + * + * @note The red byte is the middle byte in the color packet + * + * @param[in] led: The led index [0, @ref RGBLED_NUM) + * @param[in] bit: The bit number [0, 7] + * + * @return The bit index + */ +#define WS2812_RED_BIT(led, bit) WS2812_BIT((led), 1, (bit)) + +/** + * @brief Determine the index in @ref ws2812_frame_buffer "the frame buffer" of a given green bit + * + * @note The red byte is the first byte in the color packet + * + * @param[in] led: The led index [0, @ref RGBLED_NUM) + * @param[in] bit: The bit number [0, 7] + * + * @return The bit index + */ +#define WS2812_GREEN_BIT(led, bit) WS2812_BIT((led), 0, (bit)) + +/** + * @brief Determine the index in @ref ws2812_frame_buffer "the frame buffer" of a given blue bit + * + * @note The red byte is the last byte in the color packet + * + * @param[in] led: The led index [0, @ref RGBLED_NUM) + * @param[in] bit: The bit index [0, 7] + * + * @return The bit index + */ +#define WS2812_BLUE_BIT(led, bit) WS2812_BIT((led), 2, (bit)) + +/* --- PRIVATE VARIABLES ---------------------------------------------------- */ + +static uint32_t ws2812_frame_buffer[WS2812_BIT_N + 1]; /**< Buffer for a frame */ + +/* --- PUBLIC FUNCTIONS ----------------------------------------------------- */ +/* + * Gedanke: Double-buffer type transactions: double buffer transfers using two memory pointers for +the memory (while the DMA is reading/writing from/to a buffer, the application can +write/read to/from the other buffer). + */ + +void ws2812_init(void) { + // Initialize led frame buffer + uint32_t i; + for (i = 0; i < WS2812_COLOR_BIT_N; i++) ws2812_frame_buffer[i] = WS2812_DUTYCYCLE_0; // All color bits are zero duty cycle + for (i = 0; i < WS2812_RESET_BIT_N; i++) ws2812_frame_buffer[i + WS2812_COLOR_BIT_N] = 0; // All reset bits are zero + +#if defined(USE_GPIOV1) + palSetLineMode(RGB_DI_PIN, PAL_MODE_STM32_ALTERNATE_PUSHPULL); +#else + palSetLineMode(RGB_DI_PIN, PAL_MODE_ALTERNATE(WS2812_PWM_PAL_MODE) | PAL_STM32_OSPEED_HIGHEST | PAL_STM32_PUPDR_FLOATING); +#endif + + // PWM Configuration + //#pragma GCC diagnostic ignored "-Woverride-init" // Turn off override-init warning for this struct. We use the overriding ability to set a "default" channel config + static const PWMConfig ws2812_pwm_config = { + .frequency = WS2812_PWM_FREQUENCY, + .period = WS2812_PWM_PERIOD, // Mit dieser Periode wird UDE-Event erzeugt und ein neuer Wert (Länge WS2812_BIT_N) vom DMA ins CCR geschrieben + .callback = NULL, + .channels = + { + [0 ... 3] = {.mode = PWM_OUTPUT_DISABLED, .callback = NULL}, // Channels default to disabled + [WS2812_PWM_CHANNEL - 1] = {.mode = PWM_OUTPUT_ACTIVE_HIGH, .callback = NULL}, // Turn on the channel we care about + }, + .cr2 = 0, + .dier = TIM_DIER_UDE, // DMA on update event for next period + }; + //#pragma GCC diagnostic pop // Restore command-line warning options + + // Configure DMA + // dmaInit(); // Joe added this + dmaStreamAlloc(WS2812_DMA_STREAM - STM32_DMA1_STREAM1, 10, NULL, NULL); + dmaStreamSetPeripheral(WS2812_DMA_STREAM, &(WS2812_PWM_DRIVER.tim->CCR[WS2812_PWM_CHANNEL - 1])); // Ziel ist der An-Zeit im Cap-Comp-Register + dmaStreamSetMemory0(WS2812_DMA_STREAM, ws2812_frame_buffer); + dmaStreamSetTransactionSize(WS2812_DMA_STREAM, WS2812_BIT_N); + dmaStreamSetMode(WS2812_DMA_STREAM, STM32_DMA_CR_CHSEL(WS2812_DMA_CHANNEL) | STM32_DMA_CR_DIR_M2P | STM32_DMA_CR_PSIZE_WORD | STM32_DMA_CR_MSIZE_WORD | STM32_DMA_CR_MINC | STM32_DMA_CR_CIRC | STM32_DMA_CR_PL(3)); + // M2P: Memory 2 Periph; PL: Priority Level + + // Start DMA + dmaStreamEnable(WS2812_DMA_STREAM); + + // Configure PWM + // NOTE: It's required that preload be enabled on the timer channel CCR register. This is currently enabled in the + // ChibiOS driver code, so we don't have to do anything special to the timer. If we did, we'd have to start the timer, + // disable counting, enable the channel, and then make whatever configuration changes we need. + pwmStart(&WS2812_PWM_DRIVER, &ws2812_pwm_config); + pwmEnableChannel(&WS2812_PWM_DRIVER, WS2812_PWM_CHANNEL - 1, 0); // Initial period is 0; output will be low until first duty cycle is DMA'd in +} + +void ws2812_write_led(uint16_t led_number, uint8_t r, uint8_t g, uint8_t b) { + // Write color to frame buffer + for (uint8_t bit = 0; bit < 8; bit++) { + ws2812_frame_buffer[WS2812_RED_BIT(led_number, bit)] = ((r >> bit) & 0x01) ? WS2812_DUTYCYCLE_1 : WS2812_DUTYCYCLE_0; + ws2812_frame_buffer[WS2812_GREEN_BIT(led_number, bit)] = ((g >> bit) & 0x01) ? WS2812_DUTYCYCLE_1 : WS2812_DUTYCYCLE_0; + ws2812_frame_buffer[WS2812_BLUE_BIT(led_number, bit)] = ((b >> bit) & 0x01) ? WS2812_DUTYCYCLE_1 : WS2812_DUTYCYCLE_0; + } +} + +// Setleds for standard RGB +void ws2812_setleds(LED_TYPE* ledarray, uint16_t leds) { + static bool s_init = false; + if (!s_init) { + ws2812_init(); + s_init = true; + } + + for (uint16_t i = 0; i < leds; i++) { + ws2812_write_led(i, ledarray[i].r, ledarray[i].g, ledarray[i].b); + } +} |