From: Joel Holdsworth <redacted>
Date: Sun, 4 Mar 2012 14:10:44 +0000 (+0000)
Subject: fx2lafw: Implemented control of sample rates
X-Git-Tag: libsigrok-0.1.0~56
X-Git-Url: http://sigrok.org/gitweb/?a=commitdiff_plain;h=dba024420f934ff10f18eebbaad1f4e97c739259;p=libsigrok.git

fx2lafw: Implemented control of sample rates
---

diff --git a/hardware/fx2lafw/command.c b/hardware/fx2lafw/command.c
index 0e60c9aa..b3d3b6b6 100644
--- a/hardware/fx2lafw/command.c
+++ b/hardware/fx2lafw/command.c
@@ -23,12 +23,37 @@
 #include "sigrok.h"
 #include "sigrok-internal.h"
 
-int command_start_acquisition(libusb_device_handle *devhdl)
+int command_start_acquisition(libusb_device_handle *devhdl,
+	uint64_t samplerate)
 {
+	struct cmd_start_acquisition cmd;
+	int delay = 0;
+
+	/* Compute the sample rate */
+	if((SR_MHZ(48) % samplerate) == 0)
+	{
+		cmd.flags = CMD_START_FLAGS_CLK_48MHZ;
+		delay = SR_MHZ(48) / samplerate - 1;
+	} else if((SR_MHZ(30) % samplerate) == 0) {
+		cmd.flags = CMD_START_FLAGS_CLK_30MHZ;
+		delay = SR_MHZ(30) / samplerate - 1;
+	}
+
+	/* Note that sample_delay=0 is treated as sample_delay=256 */
+	if (delay <= 0 || delay > 256) {
+		sr_err("fx2lafw: Unable to sample at %dHz",
+			samplerate);
+		return SR_ERR;
+	}
+
+	cmd.sample_delay = delay;
+
+	/* Send the control message */
 	const int res = libusb_control_transfer(devhdl,
 				LIBUSB_REQUEST_TYPE_VENDOR |
 				LIBUSB_ENDPOINT_OUT, CMD_START, 0x0000,
-				0x0000, NULL, 0, 100);
+				0x0000, (unsigned char*)&cmd,
+				sizeof(cmd), 100);
 	if (res < 0) {
 		sr_err("fx2lafw: Unable to send start command: %d",
 			res);
diff --git a/hardware/fx2lafw/command.h b/hardware/fx2lafw/command.h
index cbb76d7f..929118a0 100644
--- a/hardware/fx2lafw/command.h
+++ b/hardware/fx2lafw/command.h
@@ -21,4 +21,20 @@
 #define CMD_GET_FW_VERSION	0xb0
 #define CMD_START		0xb1
 
-int command_start_acquisition(libusb_device_handle *devhdl);
+#define CMD_START_FLAGS_CLK_SRC_POS	6
+
+#define CMD_START_FLAGS_CLK_30MHZ	(0 << CMD_START_FLAGS_CLK_SRC_POS)
+#define CMD_START_FLAGS_CLK_48MHZ	(1 << CMD_START_FLAGS_CLK_SRC_POS)
+
+#pragma pack(push, 1)
+
+struct cmd_start_acquisition
+{
+	uint8_t flags;
+	uint8_t sample_delay;
+};
+
+#pragma pack(pop)
+
+int command_start_acquisition(libusb_device_handle *devhdl,
+	uint64_t samplerate);
diff --git a/hardware/fx2lafw/fx2lafw.c b/hardware/fx2lafw/fx2lafw.c
index e213df9c..cb9963f5 100644
--- a/hardware/fx2lafw/fx2lafw.c
+++ b/hardware/fx2lafw/fx2lafw.c
@@ -625,7 +625,8 @@ static int hw_dev_acquisition_start(int dev_index, void *cb_data)
 		return SR_ERR_MALLOC;
 	}
 
-	if ((err = command_start_acquisition (ctx->usb->devhdl)) != SR_OK) {
+	if ((err = command_start_acquisition (ctx->usb->devhdl,
+		ctx->cur_samplerate)) != SR_OK) {
 		return err;
 	}