qmk-dactyl-manuform-a/keyboards/matrix/noah/ws2812_f4.c

273 lines
11 KiB
C
Raw Normal View History

/**
* @file ws2812.c
* @author Austin Glaser <austin.glaser@gmail.com>, Joerg Wangemann <joerg.wangemann@gmail.com>
* @brief WS2812 LED driver
*
* Copyright (C) 2016 Austin Glaser, 2017 Joerg Wangemann
*
* This software may be modified and distributed under the terms
* of the MIT license. See the LICENSE file for details.
*
* @todo Put in names and descriptions of variables which need to be defined to use this file
*
* @addtogroup WS2812
* @{
*/
/* --- PRIVATE DEPENDENCIES ------------------------------------------------- */
// This Driver
#include "ws2812_f4.h"
// Standard
#include <stdint.h>
// ChibiOS
#include "ch.h"
#include "hal.h"
#include "wait.h"
// Application
//#include "board.h"
// TODO: Add these #define's to the headers of your project.
// Pin, timer and dma are all connected, check them all if you change one.
// Tested with STM32F4, working at 144 or 168 MHz.
//#define WS2812_LED_N 2 // Number of LEDs
//#define PORT_WS2812 GPIOB
//#define PIN_WS2812 9
//#define WS2812_TIM_N 4 // timer, 1-11
//#define WS2812_TIM_CH 3 // timer channel, 0-3
//#define WS2812_DMA_STREAM STM32_DMA1_STREAM2 // DMA stream for TIMx_UP (look up in reference manual under DMA Channel selection)
//#define WS2812_DMA_CHANNEL 6 // DMA channel for TIMx_UP
// The WS2812 expects 5V signal level (or at least 0.7 * VDD). Sometimes it works
// with a 3V signal level, otherwise the easiest way to get the signal level to 5V
// is to add an external pullup resistor from the DI pin to 5V (10k will do) and
// configure the pin as open drain.
// (An SMD resistor is easily solders on the connections of a light strip)
// Uncomment the next line if an external pullup resistor is used.
//#define WS2812_EXTERNAL_PULLUP
/* --- CONFIGURATION CHECK -------------------------------------------------- */
#if !defined(WS2812_LED_N)
#error WS2812 LED chain length not specified
#elif WS2812_LED_N <= 0
#error WS2812 LED chain length set to invalid value
#endif
#if !defined(WS2812_TIM_N)
#error WS2812 timer not specified
#endif
#if defined(STM32F2XX) || defined(STM32F4XX) || defined(STM32F7XX)
#if WS2812_TIM_N <= 2
#define WS2812_AF 1
#elif WS2812_TIM_N <= 5
#define WS2812_AF 2
#elif WS2812_TIM_N <= 11
#define WS2812_AF 3
#endif
#elif !defined(WS2812_AF)
#error WS2812_AF timer alternate function not specified
#endif
#if !defined(WS2812_TIM_CH)
#error WS2812 timer channel not specified
#elif WS2812_TIM_CH >= 4
#error WS2812 timer channel set to invalid value
#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/800000) /**< 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 (WS2812_LED_N*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/(1000000000/450))
/**
* @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/(1000000000/900))
/* --- PRIVATE MACROS ------------------------------------------------------- */
/**
* @brief Generates a reference to a numbered PWM driver
*
* @param[in] n: The driver (timer) number
*
* @return A reference to the driver
*/
#define PWMD(n) CONCAT_EXPANDED_SYMBOLS(PWMD, n)
#define WS2812_PWMD PWMD(WS2812_TIM_N) /**< The PWM driver to use for the LED chain */
/**
* @brief Determine the index in @ref ws2812_frame_buffer "the frame buffer" of a given bit
*
* @param[in] led: The led index [0, @ref WS2812_LED_N)
* @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 WS2812_LED_N)
* @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 green byte is the first byte in the color packet
*
* @param[in] led: The led index [0, @ref WS2812_LED_N)
* @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 blue byte is the last byte in the color packet
*
* @param[in] led: The led index [0, @ref WS2812_LED_N)
* @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
// Configure pin as AF output. If there's an external pull up resistor the signal level is brought to 5V using open drain mode.
#ifdef WS2812_EXTERNAL_PULLUP
palSetPadMode(PORT_WS2812, PIN_WS2812, PAL_MODE_ALTERNATE(WS2812_AF) | PAL_STM32_OTYPE_OPENDRAIN);
#else
palSetPadMode(PORT_WS2812, PIN_WS2812, PAL_MODE_ALTERNATE(WS2812_AF) | PAL_STM32_OTYPE_PUSHPULL); //PAL_MODE_STM32_ALTERNATE_PUSHPULL);
#endif
//palClearPad(PORT_WS2812, PIN_WS2812);
//wait_ms(1);
// 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_TIM_CH] = {.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
dmaStreamAllocate(WS2812_DMA_STREAM, 10, NULL, NULL);
dmaStreamSetPeripheral(WS2812_DMA_STREAM, &(WS2812_PWMD.tim->CCR[WS2812_TIM_CH])); // 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_PWMD, &ws2812_pwm_config);
pwmEnableChannel(&WS2812_PWMD, WS2812_TIM_CH, 0); // Initial period is 0; output will be low until first duty cycle is DMA'd in
}
ws2812_err_t ws2812_write_led(uint32_t led_number, uint8_t r, uint8_t g, uint8_t b)
{
// Check for valid LED
if (led_number > WS2812_LED_N) return WS2812_LED_INVALID;
// Write color to frame buffer
for (uint32_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;
}
// Success
return WS2812_SUCCESS;
}
void ws2812_setleds(LED_TYPE *ledarray, uint16_t number_of_leds)
{
for(int i = 0; i < number_of_leds; i++) {
ws2812_write_led(i, ledarray[i].r, ledarray[i].g, ledarray[i].b);
}
}
/** @} addtogroup WS2812 */