invert I2S CLK output to clock out data on rising edge

rorosaurus · Sep 30, 2019 · ebf12e4 · ebf12e4
1 parent cb0f538
commit ebf12e4
Showing 1 changed file with 10 additions and 2 deletions.
diff --git a/src/esp32_i2s_parallel.c b/src/esp32_i2s_parallel.c
@@ -128,6 +128,13 @@ static void gpio_setup_out(int gpio, int sig) {
     gpio_matrix_out(gpio, sig, false, false);
 }
 
+static void gpio_setup_out_invert(int gpio, int sig) {
+    if (gpio==-1) return;
+    PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[gpio], PIN_FUNC_GPIO);
+    gpio_set_direction(gpio, GPIO_MODE_DEF_OUTPUT);
+    gpio_matrix_out(gpio, sig, true, false);
+}
+
 
 static void dma_reset(i2s_dev_t *dev) {
     dev->lc_conf.in_rst=1; dev->lc_conf.in_rst=0;
@@ -284,8 +291,9 @@ void i2s_parallel_setup_without_malloc(i2s_dev_t *dev, const i2s_parallel_config
     for (int x=0; x<cfg->bits; x++) {
         gpio_setup_out(cfg->gpio_bus[x], sig_data_base+x);
     }
-    //ToDo: Clk/WS may need inversion?
-    gpio_setup_out(cfg->gpio_clk, sig_clk);
+
+    // invert CLK output to clock out data on rising edge
+    gpio_setup_out_invert(cfg->gpio_clk, sig_clk);
 
     //Power on dev
     if (dev==&I2S0) {