Add driver for APA102 LED controller. These LEDs are used on LED Strips and are controlled over SPI.

include/nuttx/leds/apa102.h

@@ -0,0 +1,114 @@
+/****************************************************************************
+ * include/nuttx/leds/apa102.h
+ *
+ *   Copyright (C) 2017 Alan Carvalho de Assis.
+ *   Author: Alan Carvalho de Assis <acassis@gmail.com>
+ *
+ * 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 NuttX 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.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_LEDS_APA102_H
+#define __INCLUDE_NUTTX_LEDS_APA102_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+/* Configuration
+ * CONFIG_SPI         - Enables support for SPI drivers
+ * CONFIG_LEDS_APA102 - Enables support for the APA102 driver
+ */
+
+#if defined(CONFIG_SPI) && defined(CONFIG_LEDS_APA102)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* SPI definitions */
+
+#define APA102_SPI_MAXFREQUENCY    (100000) /* Default 4MHz */
+
+/* APA102 register addresses */
+
+#define APA102_START_FRAME         0x00000000
+#define APA102_HEADER_FRAME        0xe1
+#define APA102_END_FRAME           0x00
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+struct apa102_ledstrip_s
+{
+  uint8_t bright;
+  uint8_t blue;
+  uint8_t green;
+  uint8_t red;
+};
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: apa102_register
+ *
+ * Description:
+ *   Register the APA102 device as 'devpath'
+ *
+ * Input Parameters:
+ *   devpath - The full path to the driver to register. E.g., "/dev/leddrv0".
+ *   spi     - An instance of the SPI interface to use to communicate
+ *             with the APA102.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int apa102_register(FAR const char *devpath, FAR struct spi_dev_s *spi);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CONFIG_SPI && CONFIG_LEDS_APA102 */
+#endif /* __INCLUDE_NUTTX_LEDS_APA102_H */