Added WS2801 support

app/include/user_modules.h

@@ -29,6 +29,7 @@
 #define LUA_USE_MODULES_MQTT
 #define LUA_USE_MODULES_COAP
 #define LUA_USE_MODULES_U8G
+#define LUA_USE_MODULES_WS2801
 #define LUA_USE_MODULES_WS2812
 #define LUA_USE_MODULES_CJSON
 #define LUA_USE_MODULES_CRYPTO

app/modules/modules.h

@@ -133,6 +133,14 @@
 #define ROM_MODULES_BIT
 #endif
 
+#if defined(LUA_USE_MODULES_WS2801)
+#define MODULES_WS2801      "ws2801"
+#define ROM_MODULES_WS2801  \
+    _ROM(MODULES_WS2801, luaopen_ws2801, ws2801_map)
+#else
+#define ROM_MODULES_WS2801
+#endif
+
 #if defined(LUA_USE_MODULES_WS2812)
 #define MODULES_WS2812      "ws2812"
 #define ROM_MODULES_WS2812  \
@@ -190,6 +198,7 @@
         ROM_MODULES_UART    \
         ROM_MODULES_OW      \
         ROM_MODULES_BIT     \
+        ROM_MODULES_WS2801  \
         ROM_MODULES_WS2812  \
         ROM_MODULES_CJSON   \
         ROM_MODULES_CRYPTO  \

app/modules/ws2801.c

@@ -0,0 +1,140 @@
+#include "lualib.h"
+#include "lauxlib.h"
+#include "platform.h"
+#include "auxmods.h"
+#include "lrotable.h"
+#include "c_stdlib.h"
+#include "c_string.h"
+
+/**
+ * Code is based on https://github.com/CHERTS/esp8266-devkit/blob/master/Espressif/examples/EspLightNode/user/ws2801.c
+ * and provides a similar api as the ws2812 module.
+ * The current implementation allows the caller to use
+ * any combination of GPIO0, GPIO2, GPIO4, GPIO5 as clock and data.
+ */
+
+#define PIN_CLK_DEFAULT         0
+#define PIN_DATA_DEFAULT        2
+
+static uint32_t ws2801_bit_clk;
+static uint32_t ws2801_bit_data;
+
+static void ws2801_byte(uint8_t n) {
+    uint8_t bitmask;
+    for (bitmask = 0x80; bitmask !=0 ; bitmask >>= 1) {
+        if (n & bitmask) {
+            GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, ws2801_bit_data);
+        } else {
+            GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, ws2801_bit_data);
+        }
+        GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, ws2801_bit_clk);
+        GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, ws2801_bit_clk);
+    }
+}
+
+static void ws2801_color(uint8_t r, uint8_t g, uint8_t b) {
+    ws2801_byte(r);
+    ws2801_byte(g);
+    ws2801_byte(b);
+}
+
+static void ws2801_strip(uint8_t const * data, uint16_t len) {
+    while (len--) {
+        ws2801_byte(*(data++));
+    }
+    GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, ws2801_bit_data);
+}
+
+static void enable_pin_mux(pin) {
+    // The API only supports setting PERIPHS_IO_MUX on GPIO 0, 2, 4, 5
+    switch (pin) {
+    case 0:
+        PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO0_U, FUNC_GPIO0);
+        break;
+    case 2:
+        PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO2_U, FUNC_GPIO2);
+        break;
+    case 4:
+        PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO4_U, FUNC_GPIO4);
+        break;
+    case 5:
+        PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO5_U, FUNC_GPIO5);
+        break;
+    default:
+        break;
+    }
+}
+
+/* Lua: ws2801.init(pin_clk, pin_data)
+ * Sets up the GPIO pins
+ * 
+ * ws2801.init(0, 2) uses GPIO0 as clock and GPIO2 as data.
+ * This is the default behavior.
+ */
+static int ICACHE_FLASH_ATTR ws2801_init_lua(lua_State* L) {
+    uint32_t pin_clk;
+    uint32_t pin_data;
+    uint32_t func_gpio_clk;
+    uint32_t func_gpio_data;
+
+    if (!lua_isnumber(L, 1) || !lua_isnumber(L, 2)) {
+        // Use default pins if the input is omitted
+        pin_clk = PIN_CLK_DEFAULT;
+        pin_data = PIN_DATA_DEFAULT;
+    } else {
+        pin_clk = luaL_checkinteger(L, 1);
+        pin_data = luaL_checkinteger(L, 2);
+    }
+
+    ws2801_bit_clk = 1 << pin_clk;
+    ws2801_bit_data = 1 << pin_data;
+
+    os_delay_us(10);
+
+    //Set GPIO pins to output mode
+    enable_pin_mux(pin_clk);
+    enable_pin_mux(pin_data);
+
+    //Set both GPIOs low low
+    gpio_output_set(0, ws2801_bit_clk | ws2801_bit_data, ws2801_bit_clk | ws2801_bit_data, 0);
+
+    os_delay_us(10);
+}
+
+/* Lua: ws2801.write(pin, "string")
+ * Byte triples in the string are interpreted as R G B values.
+ * This function does not corrupt your buffer.
+ *
+ * ws2801.write(string.char(255, 0, 0)) sets the first LED red.
+ * ws2801.write(string.char(0, 0, 255):rep(10)) sets ten LEDs blue.
+ * ws2801.write(string.char(0, 255, 0, 255, 255, 255)) first LED green, second LED white.
+ */
+static int ICACHE_FLASH_ATTR ws2801_writergb(lua_State* L) {
+    size_t length;
+    const char *buffer = luaL_checklstring(L, 1, &length);
+
+    os_delay_us(10);
+
+    os_intr_lock();
+
+    ws2801_strip(buffer, length);
+
+    os_intr_unlock();
+
+    return 0;
+}
+
+#define MIN_OPT_LEVEL 2
+#include "lrodefs.h"
+const LUA_REG_TYPE ws2801_map[] =
+{
+    { LSTRKEY( "write" ), LFUNCVAL( ws2801_writergb )},
+    { LSTRKEY( "init" ), LFUNCVAL( ws2801_init_lua )},
+    { LNILKEY, LNILVAL}
+};
+
+LUALIB_API int luaopen_ws2801(lua_State *L) {
+    LREGISTER(L, "ws2801", ws2801_map);
+    return 1;
+}
+