p9813: Chainable LEDS

Initial commit of the p9813 chainable LED controller.
Added C, C++, python, java, and node examples.

Signed-off-by: Sergey Kiselev <sergey.kiselev@intel.com>
Signed-off-by: Noel Eck <noel.eck@intel.com>

src/p9813/p9813.c

@@ -0,0 +1,149 @@
+/*
+ * Author: Sergey Kiselev <sergey.kiselev@intel.com>
+ * Copyright (c) 2017 Sergey Kiselev
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <assert.h>
+
+#include "p9813.h"
+
+p9813_context p9813_init(int ledcount, int clk, int data) {
+
+    p9813_context dev = (p9813_context)malloc(sizeof(struct _p9813_context));
+
+    if(!dev)
+        return NULL;
+
+    memset(dev, 0, sizeof(struct _p9813_context));
+    dev->leds = ledcount;
+
+    // Try to allocate and zero out buffer
+    if ((dev->buffer = (uint8_t*)malloc(dev->leds * 3))) {
+        memset(dev->buffer, 0x00, dev->leds * 3);
+    } else {
+        printf("%s: Failed to allocate LED buffer.\n", __FUNCTION__);
+        p9813_close(dev);
+        return NULL;
+    }
+
+    dev->clk = NULL;
+    dev->data = NULL;
+
+    if (!(dev->clk = mraa_gpio_init(clk))) {
+        printf("%s: mraa_gpio_init(clk) failed.\n", __FUNCTION__);
+        p9813_close(dev);
+        return NULL;
+    }
+    mraa_gpio_dir(dev->clk, MRAA_GPIO_OUT);
+
+    if (!(dev->data = mraa_gpio_init(data))) {
+        printf("%s: mraa_gpio_init(data) failed.\n", __FUNCTION__);
+        p9813_close(dev);
+        return NULL;
+    }
+
+    return dev;
+}
+
+void p9813_close(p9813_context dev) {
+    assert(dev != NULL);
+
+    if (dev->clk)
+        mraa_gpio_close(dev->clk);
+    if (dev->data)
+        mraa_gpio_close(dev->data);
+    if(dev->buffer)
+        free(dev->buffer);
+    free(dev);
+}
+
+upm_result_t p9813_set_led(p9813_context dev, uint16_t index, uint8_t r, uint8_t g, uint8_t b) {
+    return p9813_set_leds(dev, index, index, r, g, b);
+}
+
+upm_result_t p9813_set_leds(p9813_context dev, uint16_t s_index, uint16_t e_index, uint8_t r, uint8_t g, uint8_t b) {
+    assert(dev != NULL);
+    int i;
+
+    for (i = s_index; i <= e_index; i++) {
+        dev->buffer[i * 3] = r;
+        dev->buffer[i * 3 + 1] = g;
+        dev->buffer[i * 3 + 2] = b;
+    }
+    return UPM_SUCCESS;
+}
+
+upm_result_t p9813_send_byte(p9813_context dev, uint8_t data)
+{
+    for (uint16_t i = 0; i < 8; i++) {
+        // Write the data bit
+        mraa_gpio_write(dev->data, (data & 0x80) >> 7);
+        // Pulse the clock
+        mraa_gpio_write(dev->clk, 1);
+        usleep(20);
+        mraa_gpio_write(dev->clk, 0);
+        usleep(20);
+
+        // Shift to the next data bit
+        data <<= 1;
+    }
+
+    return UPM_SUCCESS;
+}
+
+
+upm_result_t p9813_refresh(p9813_context dev) {
+    uint16_t i;
+    uint8_t byte0, red, green, blue;
+
+    assert(dev != NULL);
+
+    // Begin data frame
+    p9813_send_byte(dev, 0x00);
+    p9813_send_byte(dev, 0x00);
+    p9813_send_byte(dev, 0x00);
+    p9813_send_byte(dev, 0x00);
+
+    for (i = 0; i <= dev->leds; i++) {
+        red = dev->buffer[i * 3];
+        green = dev->buffer[i * 3 + 1];
+        blue = dev->buffer[i * 3 + 2];
+        // The first byte is 11 followed by inverted bits 7 and 6 of blue, green, and red
+        byte0 = 0xFF;
+        byte0 ^= (blue >> 2) & 0x30; // XOR bits 4-5
+        byte0 ^= (green >> 4) & 0xC0; // XOR bits 2-3
+        byte0 ^= (red >> 6) & 0x03; // XOR bits 0-1
+        p9813_send_byte(dev, byte0);
+        p9813_send_byte(dev, blue);
+        p9813_send_byte(dev, green);
+        p9813_send_byte(dev, red);
+    }
+
+    // End data frame
+    p9813_send_byte(dev, 0x00);
+    p9813_send_byte(dev, 0x00);
+    p9813_send_byte(dev, 0x00);
+    p9813_send_byte(dev, 0x00);
+
+    return UPM_SUCCESS;
+}