From dfc92d8f7b669af403c5be0121bbb678e5be8611 Mon Sep 17 00:00:00 2001 From: yiancar Date: Sun, 14 Aug 2022 02:36:34 +0100 Subject: [PATCH] Fix buffer size for WS2812 PWM driver (#17046) Co-authored-by: Drashna Jaelre Co-authored-by: Sergey Vlasov Co-authored-by: yiancar --- platforms/chibios/drivers/ws2812_pwm.c | 52 ++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 4 deletions(-) diff --git a/platforms/chibios/drivers/ws2812_pwm.c b/platforms/chibios/drivers/ws2812_pwm.c index 37c613049f4..8c0259fb91a 100644 --- a/platforms/chibios/drivers/ws2812_pwm.c +++ b/platforms/chibios/drivers/ws2812_pwm.c @@ -41,6 +41,22 @@ # error "please consult your MCU's datasheet and specify in your config.h: #define WS2812_DMAMUX_ID STM32_DMAMUX1_TIM?_UP" #endif +/* Summarize https://www.st.com/resource/en/application_note/an4013-stm32-crossseries-timer-overview-stmicroelectronics.pdf to + * figure out if we are using a 32bit timer. This is needed to setup the DMA controller correctly. + * Ignore STM32H7XX and STM32U5XX as they are not supported by ChibiOS. + */ +#if !defined(STM32F1XX) && !defined(STM32L0XX) && !defined(STM32L1XX) +# define WS2812_PWM_TIMER_32BIT_PWMD2 1 +#endif +#if !defined(STM32F1XX) +# define WS2812_PWM_TIMER_32BIT_PWMD5 1 +#endif +#define WS2812_CONCAT1(a, b) a##b +#define WS2812_CONCAT(a, b) WS2812_CONCAT1(a, b) +#if WS2812_CONCAT(WS2812_PWM_TIMER_32BIT_, WS2812_PWM_DRIVER) +# define WS2812_PWM_TIMER_32BIT +#endif + #ifndef WS2812_PWM_COMPLEMENTARY_OUTPUT # define WS2812_PWM_OUTPUT_MODE PWM_OUTPUT_ACTIVE_HIGH #else @@ -101,6 +117,9 @@ * The duty cycle is calculated for a high period of 350 nS. */ #define WS2812_DUTYCYCLE_0 (WS2812_PWM_FREQUENCY / (1000000000 / 350)) +#if (WS2812_DUTYCYCLE_0 > 255) +# error WS2812 PWM driver: High period for a 0 is more than a byte +#endif /** * @brief High period for a one, in ticks @@ -117,6 +136,9 @@ * This is in the middle of the specifications of the WS2812 and WS2812B. */ #define WS2812_DUTYCYCLE_1 (WS2812_PWM_FREQUENCY / (1000000000 / 800)) +#if (WS2812_DUTYCYCLE_1 > 255) +# error WS2812 PWM driver: High period for a 1 is more than a byte +#endif /* --- PRIVATE MACROS ------------------------------------------------------- */ @@ -259,13 +281,35 @@ /* --- PRIVATE VARIABLES ---------------------------------------------------- */ -static uint32_t ws2812_frame_buffer[WS2812_BIT_N + 1]; /**< Buffer for a frame */ +// STM32F2XX, STM32F4XX and STM32F7XX do NOT zero pad DMA transfers of unequal data width. Buffer width must match TIMx CCR. +// For all other STM32 DMA transfer will automatically zero pad. We only need to set the right peripheral width. +#if defined(STM32F2XX) || defined(STM32F4XX) || defined(STM32F7XX) +# if defined(WS2812_PWM_TIMER_32BIT) +# define WS2812_DMA_MEMORY_WIDTH STM32_DMA_CR_MSIZE_WORD +# define WS2812_DMA_PERIPHERAL_WIDTH STM32_DMA_CR_PSIZE_WORD +typedef uint32_t ws2812_buffer_t; +# else +# define WS2812_DMA_MEMORY_WIDTH STM32_DMA_CR_MSIZE_HWORD +# define WS2812_DMA_PERIPHERAL_WIDTH STM32_DMA_CR_PSIZE_HWORD +typedef uint16_t ws2812_buffer_t; +# endif +#else +# define WS2812_DMA_MEMORY_WIDTH STM32_DMA_CR_MSIZE_BYTE +# if defined(WS2812_PWM_TIMER_32BIT) +# define WS2812_DMA_PERIPHERAL_WIDTH STM32_DMA_CR_PSIZE_WORD +# else +# define WS2812_DMA_PERIPHERAL_WIDTH STM32_DMA_CR_PSIZE_HWORD +# endif +typedef uint8_t ws2812_buffer_t; +#endif + +static ws2812_buffer_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). + * 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) { @@ -305,7 +349,7 @@ void ws2812_init(void) { dmaStreamAlloc(WS2812_DMA_STREAM - STM32_DMA_STREAM(0), 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); - 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)); + dmaStreamSetMode(WS2812_DMA_STREAM, STM32_DMA_CR_CHSEL(WS2812_DMA_CHANNEL) | STM32_DMA_CR_DIR_M2P | WS2812_DMA_PERIPHERAL_WIDTH | WS2812_DMA_MEMORY_WIDTH | STM32_DMA_CR_MINC | STM32_DMA_CR_CIRC | STM32_DMA_CR_PL(3)); #endif dmaStreamSetTransactionSize(WS2812_DMA_STREAM, WS2812_BIT_N); // M2P: Memory 2 Periph; PL: Priority Level