Add SK6812 Serial PWM LED Driver

platforms/nuttx/src/px4/common/CMakeLists.txt

@@ -64,3 +64,4 @@ endif()
 add_dependencies(px4_layer prebuild_targets)
 
 add_subdirectory(gpio)
+add_subdirectory(srgbled)

platforms/nuttx/src/px4/common/srgbled/CMakeLists.txt

@@ -0,0 +1,36 @@
+############################################################################
+#
+#   Copyright (c) 2021 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+px4_add_library(platform_srgbled
+	srgbled.cpp
+)

platforms/nuttx/src/px4/common/srgbled/srgbled.cpp

@@ -0,0 +1,128 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2021 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+* @file srgbled.cpp
+* Author: David.Sidrane@Nscdg.com*
+*  This is a driver for the the neopixel class of serial RGB LEDs.
+*
+*  It is arch dependent on ARM for the DWT and the GPIO is done in arch
+*  independent manner.
+*
+*  To use this driver the board must define:
+
+*  BOARD_HAS_N_S_RGB_LED  - the number of LEDs
+*  BOARD_SRGBLED_BIT      - the bit number it is connected to. 0-n (not a mask)
+        and
+*  BOARD_SRGBLED_PORT     - The address of the port's "data out" register
+*                           the LED is connected to.
+*       OR
+*  BOARD_SRGBLED_SET_PORT - for an arch with set/clear GPIO. The address of the
+*                           port's "SET Bit" register
+*  BOARD_SRGBLED_CLEAR    - for an arch with set/clear GPIO.  The address of the
+*                           port's "Clear Bit" register
+*
+*  N.B. This version is small but will disable interrupts for 30 us per LED!
+*  With an 8 LED's this is 240uS and not tolerable for systems with sensors.
+*  It is however useful in bootloaders.
+*
+*  The DMA version of this driver should be used for systems that can not have
+*  interrupts for long times.
+*
+*/
+
+#include <px4_platform_common/px4_config.h>
+#include <drivers/drv_neopixel.h>
+#include <board_config.h>
+#include <dwt.h>
+#include <nvic.h>
+
+#define REG(_addr)       (*(volatile uint32_t *)(_addr))
+#define rDEMCR           REG(NVIC_DEMCR)
+#define rDWT_CTRL        REG(DWT_CTRL)
+#define rDWT_CNT         REG(DWT_CYCCNT)
+
+#if defined(BOARD_SRGBLED_PORT) && defined(BOARD_SRGBLED_BIT)
+#  define PORT             REG(BOARD_SRGBLED_PORT)
+#  define D0               ((PORT) &= ~(1 << BOARD_SRGBLED_BIT));
+#  define D1               ((PORT) |= (1 << BOARD_SRGBLED_BIT));
+#elif defined(BOARD_SRGBLED_SET_PORT) && defined(BOARD_SRGBLED_CLEAR_PORT)  && defined(BOARD_SRGBLED_BIT)
+#  define PORT             REG(BOARD_SRGBLED_PORT)
+#  define D0               ((BOARD_SRGBLED_CLEAR_PORT) |= (1 << BOARD_SRGBLED_BIT));
+#  define D1               ((BOARD_SRGBLED_SET_PORT)   |= (1 << BOARD_SRGBLED_BIT));
+#else
+# error BOARD_SRGBLED_[]{SET|CLEAR}_]PORT and BOARD_SRGBLED_BIT needs to be defined.
+#endif
+
+#define DWT_DEADLINE(t)  rDWT_CNT + (t)
+#define DWT_WAIT(v, D)   while((rDWT_CNT - (v)) < (D)){}
+
+#define T0H              (STM32_SYSCLK_FREQUENCY/3333333)
+#define T1H              (STM32_SYSCLK_FREQUENCY/1666666)
+#define TW               (STM32_SYSCLK_FREQUENCY/850000)
+
+#define COLOR_PER_LED   3  // There is a R G B in each package.
+#define BITS_PER_COLOR  8  // Each LED has 8 bits of luminosity
+#define BITS_PER_PACKAGE (BITS_PER_COLOR * COLOR_PER_LED)
+
+#if defined(BOARD_HAS_N_S_RGB_LED) && !defined(S_RGB_LED_DMA)
+
+
+int neopixel_write_no_dma(uint8_t r, uint8_t g, uint8_t b, uint8_t led_count)
+{
+	register neopixel::NeoLEDData::led_data_t data;
+	data.grb[2] = g;
+	data.grb[1] = r;
+	data.grb[0] = b;
+	rDEMCR    |= NVIC_DEMCR_TRCENA;
+	rDWT_CTRL |= DWT_CTRL_CYCCNTENA_MASK;
+	irqstate_t state = px4_enter_critical_section();
+
+	while (led_count--) {
+		uint32_t  deadline = DWT_DEADLINE(TW);
+
+		for (uint32_t mask = 1 << (BITS_PER_PACKAGE - 1);  mask != 0;  mask >>= 1) {
+			DWT_WAIT(deadline, TW);
+			deadline = rDWT_CNT;
+			D1;
+			DWT_WAIT(deadline, data.l & mask ? T1H : T0H);
+			D0;
+		}
+
+		DWT_WAIT(deadline, TW);
+	}
+
+	px4_leave_critical_section(state);
+	return 0;
+}
+#endif // BOARD_HAS_SRGBLED

src/drivers/lights/rgbled_pwm/rgbled_pwm.cpp

@@ -72,6 +72,7 @@ private:
 };
 
 extern int led_pwm_servo_set(unsigned channel, uint8_t  value);
+extern int led_pwm_servo_set_ex(uint8_t r, uint8_t g, uint8_t b, uint8_t led_count);
 extern unsigned led_pwm_servo_get(unsigned channel);
 extern int led_pwm_servo_init(void);
 extern void led_pwm_servo_deinit(void);
@@ -208,7 +209,6 @@ RGBLED_PWM::send_led_rgb()
 	led_pwm_servo_set(4, _g);
 	led_pwm_servo_set(5, _b);
 #endif
-
 	return (OK);
 }