Factor out sample_rate_set() from cpu_clock_init().

Implement switching between several supported sampling rates for Jellybean and Jawbreaker.
Commit bits of the Si5351C USB request support that I apparently missed in a prior commit.

firmware/common/hackrf_core.c

@@ -36,6 +36,96 @@ void delay(uint32_t duration)
 		__asm__("nop");
 }
 
+bool sample_rate_set(const uint32_t sample_rate_hz) {
+#ifdef JELLYBEAN
+	/* Due to design issues, Jellybean/Lemondrop frequency plan is limited.
+	 * Long version of the story: The MAX2837 reference frequency
+	 * originates from the same PLL as the sample clocks, and in order to
+	 * keep the sample clocks in phase and keep jitter noise down, the MAX2837
+	 * and sample clocks must be integer-related.
+	 */
+	uint32_t r_div_sample = 2;
+	uint32_t r_div_sgpio = 1;
+	
+	switch( sample_rate_hz ) {
+	case 5000000:
+		r_div_sample = 3;	/* 800 MHz / 20 / 8 =  5 MHz */
+		r_div_sgpio = 2;	/* 800 MHz / 20 / 4 = 10 MHz */
+		break;
+		
+	case 10000000:
+		r_div_sample = 2;	/* 800 MHz / 20 / 4 = 10 MHz */
+		r_div_sgpio = 1;	/* 800 MHz / 20 / 2 = 20 MHz */
+		break;
+		
+	case 20000000:
+		r_div_sample = 1;	/* 800 MHz / 20 / 2 = 20 MHz */
+		r_div_sgpio = 0;	/* 800 MHz / 20 / 1 = 40 MHz */
+		break;
+		
+	default:
+		return false;
+	}
+	
+	/* NOTE: Because MS1, 2, 3 outputs are slaved to PLLA, the p1, p2, p3
+	 * values are irrelevant. */
+	
+	/* MS0/CLK1 is the source for the MAX5864 codec. */
+	si5351c_configure_multisynth(1, 4608, 0, 1, r_div_sample);
+
+	/* MS0/CLK2 is the source for the CPLD codec clock (same as CLK1). */
+	si5351c_configure_multisynth(2, 4608, 0, 1, r_div_sample);
+
+	/* MS0/CLK3 is the source for the SGPIO clock. */
+	si5351c_configure_multisynth(3, 4608, 0, 1, r_div_sgpio);
+	
+	return true;
+#endif
+	
+#ifdef JAWBREAKER
+	uint32_t p1 = 4608;
+	
+	switch(sample_rate_hz) {
+	case 5000000:
+		p1 = 9728;	// 800MHz / 80 = 10 MHz (SGPIO), 5 MHz (codec)
+		break;
+	
+	case 10000000:
+		p1 = 4608;	// 800MHz / 40 = 20 MHz (SGPIO), 10 MHz (codec)
+		break;
+
+	case 12500000:
+		p1 = 3584;	// 800MHz / 32 = 25 MHz (SGPIO), 12.5 MHz (codec)
+		break;
+
+	case 16000000:
+		p1 = 2688;	// 800MHz / 25 = 32 MHz (SGPIO), 16 MHz (codec)
+		break;
+	
+	case 20000000:
+		p1 = 2048;	// 800MHz / 20 = 40 MHz (SGPIO), 20 MHz (codec)
+		break;
+	
+	default:
+		return false;
+	}
+	
+	/* MS0/CLK0 is the source for the MAX5864/CPLD (CODEC_CLK). */
+	si5351c_configure_multisynth(0, p1, 0, 1, 1);
+
+	/* MS0/CLK1 is the source for the CPLD (CODEC_X2_CLK). */
+	si5351c_configure_multisynth(1, p1, 0, 1, 0);
+
+	/* MS0/CLK2 is the source for SGPIO (CODEC_X2_CLK) */
+	si5351c_configure_multisynth(2, p1, 0, 1, 0);
+
+	/* MS0/CLK3 is the source for the external clock output. */
+	si5351c_configure_multisynth(3, p1, 0, 1, 0);
+
+	return true;
+#endif
+}
+
 /* clock startup for Jellybean with Lemondrop attached */ 
 void cpu_clock_init(void)
 {
@@ -68,15 +158,6 @@ void cpu_clock_init(void)
 	/* MS0/CLK0 is the source for the MAX2837 clock input. */
 	si5351c_configure_multisynth(0, 2048, 0, 1, 0); /* 40MHz */
 
-	/* MS0/CLK1 is the source for the MAX5864 codec. */
-	si5351c_configure_multisynth(1, 4608, 0, 1, 2); /* 10MHz */
-
-	/* MS0/CLK2 is the source for the CPLD codec clock (same as CLK1). */
-	si5351c_configure_multisynth(2, 4608, 0, 1, 2); /* 10MHz */
-
-	/* MS0/CLK3 is the source for the SGPIO clock. */
-	si5351c_configure_multisynth(3, 4608, 0, 1, 1); /* 20MHz */
-
 	/* MS4/CLK4 is the source for the LPC43xx microcontroller. */
 	si5351c_configure_multisynth(4, 8021, 0, 3, 0); /* 12MHz */
 
@@ -97,18 +178,6 @@ void cpu_clock_init(void)
 	 *   CLK7 -> LPC4330 (but LPC4330 starts up on its own crystal)
 	 */
 
-	/* MS0/CLK0 is the source for the MAX5864/CPLD (CODEC_CLK). */
-	si5351c_configure_multisynth(0, 4608, 0, 1, 1); /* 10MHz */
-
-	/* MS0/CLK1 is the source for the CPLD (CODEC_X2_CLK). */
-	si5351c_configure_multisynth(1, 4608, 0, 1, 0); /* 20MHz */
-
-	/* MS0/CLK2 is the source for SGPIO (CODEC_X2_CLK) */
-	si5351c_configure_multisynth(2, 4608, 0, 1, 0); /* 20MHz */
-
-	/* MS0/CLK3 is the source for the external clock output. */
-	si5351c_configure_multisynth(3, 4608, 0, 1, 0); /* 20MHz */
-
 	/* MS4/CLK4 is the source for the RFFC5071 mixer. */
 	si5351c_configure_multisynth(4, 1536, 0, 1, 0); /* 50MHz */
 
@@ -119,6 +188,9 @@ void cpu_clock_init(void)
 	//si5351c_configure_multisynth(7, 8021, 0, 3, 0); /* 12MHz */
 #endif
 
+	/* Set to 10 MHz, the common rate between Jellybean and Jawbreaker. */
+	sample_rate_set(10000000);
+
 	si5351c_configure_clock_control();
 	si5351c_enable_clock_outputs();
 

firmware/common/hackrf_core.h

@@ -30,6 +30,7 @@ extern "C"
 #endif
 
 #include <stdint.h>
+#include <stdbool.h>
 
 /* hardware identification number */
 #define BOARD_ID_JELLYBEAN  0
@@ -216,6 +217,8 @@ void pin_setup(void);
 
 void enable_1v8_power(void);
 
+bool sample_rate_set(const uint32_t sampling_rate_hz);
+
 #ifdef __cplusplus
 }
 #endif

firmware/usb_performance/usb_performance.c

@@ -293,6 +293,22 @@ bool usb_vendor_request_read_si5351c(
 	}
 }
 
+bool usb_vendor_request_set_sample_rate(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage
+) {
+	if( stage == USB_TRANSFER_STAGE_SETUP ) {
+		const uint32_t sample_rate = (endpoint->setup.index << 16) | endpoint->setup.value;
+		if( sample_rate_set(sample_rate) ) {
+			usb_endpoint_schedule_ack(endpoint->in);
+			return true;
+		}
+		return false;
+	} else {
+		return true;
+	}
+}
+
 void usb_vendor_request(
 	usb_endpoint_t* const endpoint,
 	const usb_transfer_stage_t stage
@@ -312,6 +328,18 @@ void usb_vendor_request(
 		success = usb_vendor_request_read_max2837(endpoint, stage);
 		break;
 		
+	case 4:
+		success = usb_vendor_request_write_si5351c(endpoint, stage);
+		break;
+		
+	case 5:
+		success = usb_vendor_request_read_si5351c(endpoint, stage);
+		break;
+	
+	case 6:
+		success = usb_vendor_request_set_sample_rate(endpoint, stage);
+		break;
+
 	default:
 		break;
 	}

host/libhackrf/examples/hackrf_transfer.c

@@ -165,6 +165,12 @@ int main(int argc, char** argv) {
 
 	signal(SIGINT, sigint_callback_handler);
 	
+	result = hackrf_sample_rate_set(device, 10000000);
+	if( result != HACKRF_SUCCESS ) {
+		printf("hackrf_sample_rate_set() failed: %s (%d)\n", hackrf_error_name(result), result);
+		return -1;
+	}
+	
 	if( transceiver_mode == TRANSCEIVER_MODE_RX ) {
 		result = hackrf_start_rx(device, rx_callback);
 	} else {

host/libhackrf/src/hackrf.c

@@ -34,6 +34,7 @@ typedef enum {
 	HACKRF_VENDOR_REQUEST_MAX2837_READ = 3,
 	HACKRF_VENDOR_REQUEST_SI5351C_WRITE = 4,
 	HACKRF_VENDOR_REQUEST_SI5351C_READ = 5,
+	HACKRF_VENDOR_REQUEST_SAMPLE_RATE_SET = 6,
 } hackrf_vendor_request;
 
 typedef enum {
@@ -333,6 +334,25 @@ int hackrf_si5351c_write(hackrf_device* device, uint16_t register_number, uint16
 	}
 }
 
+int hackrf_sample_rate_set(hackrf_device* device, const uint32_t sampling_rate_hz) {
+	int result = libusb_control_transfer(
+		device->usb_device,
+		LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE,
+		HACKRF_VENDOR_REQUEST_SAMPLE_RATE_SET,
+		sampling_rate_hz & 0xffff,
+		sampling_rate_hz >> 16,
+		NULL,
+		0,
+		0
+	);
+	
+	if( result != 0 ) {
+		return HACKRF_ERROR_LIBUSB;
+	} else {
+		return HACKRF_SUCCESS;
+	}
+}
+
 static void* transfer_threadproc(void* arg) {
 	hackrf_device* device = (hackrf_device*)arg;
 	

host/libhackrf/src/hackrf.h

@@ -53,8 +53,6 @@ int hackrf_exit();
 int hackrf_open(hackrf_device** device);
 int hackrf_close(hackrf_device* device);
 
-//int hackrf_set_sampling_rate(float sampling_rate_hz);
-
 int hackrf_start_rx(hackrf_device* device, hackrf_sample_block_cb_fn callback);
 int hackrf_stop_rx(hackrf_device* device);
 
@@ -69,6 +67,8 @@ int hackrf_max2837_write(hackrf_device* device, uint8_t register_number, uint16_
 int hackrf_si5351c_read(hackrf_device* device, uint16_t register_number, uint16_t* value);
 int hackrf_si5351c_write(hackrf_device* device, uint16_t register_number, uint16_t value);
 
+int hackrf_sample_rate_set(hackrf_device* device, const uint32_t sampling_rate_hz);
+
 const char* hackrf_error_name(enum hackrf_error errcode);
 
 #endif//__HACKRF_H__