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Fix buffer size for WS2812 PWM driver #17046

Merged
merged 8 commits into from
Aug 14, 2022
Merged

Fix buffer size for WS2812 PWM driver #17046

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a751f22
Fix buffer size for WS2812 PWM driver
May 9, 2022
373fb68
Fix Formating
May 9, 2022
09f695a
Update platforms/chibios/drivers/ws2812_pwm.c
yiancar May 9, 2022
b094ded
Make driver DMA controler and Timer CCR size aware
May 10, 2022
e5df3f0
Merge
May 10, 2022
e06a6bb
Update platforms/chibios/drivers/ws2812_pwm.c
yiancar May 15, 2022
a8944ab
typedef buffer size
yiancar May 15, 2022
85c140a
Merge branch 'develop' into WS2812_PWM_Driver_buffer
drashna Aug 14, 2022
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52 changes: 48 additions & 4 deletions platforms/chibios/drivers/ws2812_pwm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand All @@ -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 ------------------------------------------------------- */

Expand Down Expand Up @@ -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) {
Expand Down Expand Up @@ -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
Expand Down