Merge pull request #57 from xmos/release/v5.5.0

Release/v5.5.0

CHANGELOG.md

@@ -1,5 +1,9 @@
 # VocalFusion Raspberry Pi Setup Change Log
 
+## 5.5.0
+
+  * Add tool for setting arbitrary I2S clock
+
 ## 5.4.0
 
   * Add support for XVF3800

resources/clk_dac_setup/Makefile

@@ -1,11 +1,14 @@
-default: bclk mclk
+default: bclk mclk setup_arbitrary_i2s_rate
 
 bclk: setup_mclk_bclk.c
 	gcc -g -o setup_bclk setup_mclk_bclk.c
 
 mclk: setup_mclk_bclk.c
 	gcc -g -DMCLK -o setup_mclk setup_mclk_bclk.c
 
+setup_arbitrary_i2s_rate: setup_mclk_bclk.c
+	gcc -g -DARBITRARY_LRCLK -o setup_arbitrary_i2s_rate setup_mclk_bclk.c
+
 clean:
 	rm -f setup_mclk
 	rm -f setup_bclk

resources/clk_dac_setup/setup_mclk_bclk.c

@@ -99,6 +99,18 @@ void gpioSetMode(unsigned gpio, unsigned mode)
     gpioReg[reg] = (gpioReg[reg] & ~(7<<shift)) | (mode<<shift);
 }
 
+struct clk_reg_t {
+    int i;
+    int f;
+};
+
+struct clk_reg_t calc_register_values(double input_khz, double output_khz) {
+    int i = input_khz/output_khz;
+    return (struct clk_reg_t) {
+        .i = i,
+        .f = ((input_khz/output_khz) - i) * 4096
+    };
+}
 
 unsigned getGpioHardwareRevision(void)
 {
@@ -279,6 +291,31 @@ int main(int argc, char *argv[])
     printf("MCLK at %.3fkHz: using %s (I=%-4d F=%-4d MASH=%d)\n",
             (float)(source_clk_kHz / (clk_i + (float) clk_f/4096)),
             clocks[clk_source], clk_i, clk_f, clk_mash);
+#elif defined(ARBITRARY_LRCLK)
+    if(argc <= 1) {
+        return 1;
+    }
+
+    double desired = atof(argv[1]);
+    if(desired < 8000) {
+        printf("bad arg, expected valid clock rate in hz");
+        return 1;
+    }
+    printf("requested lrclk %f\n", desired);
+
+    int clk_index = 2;
+    int clk_source = 0;
+    int clk_mash = 1;
+    int clk_enable = 1;
+    double bclk_per_lrclk = 64;
+    struct clk_reg_t c = calc_register_values(source_clk_kHz, (desired*bclk_per_lrclk)/1000);
+    int clk_i = c.i;
+    int clk_f = c.f;
+
+    printf("BCLK at %.3fkHz: using %s (I=%-4d F=%-4d MASH=%d)\n",
+            (float)(source_clk_kHz / (clk_i + (float) clk_f/4096)),
+            clocks[clk_source], clk_i, clk_f, clk_mash);
+
 #else
     int i2s_16000 = 0;
     if (argc > 1){