From: Daniel Elstner <redacted>
Date: Sun, 25 Oct 2015 02:44:55 +0000 (+0100)
Subject: sysclk-lwla: Read test word twice during initialization
X-Git-Tag: libsigrok-0.4.0~146
X-Git-Url: http://sigrok.org/gitweb/?a=commitdiff_plain;h=e1172cf847e522b07d063c36c3f54b0a5dc8429f;p=libsigrok.git

sysclk-lwla: Read test word twice during initialization

During initialization of the LWLA1034, read the 64-bit test word
twice and verify the result of the second read only. This better
matches what the original vendor software does.
---

diff --git a/src/hardware/sysclk-lwla/lwla.c b/src/hardware/sysclk-lwla/lwla.c
index 1934d617..aee9d060 100644
--- a/src/hardware/sysclk-lwla/lwla.c
+++ b/src/hardware/sysclk-lwla/lwla.c
@@ -191,6 +191,33 @@ SR_PRIV int lwla_read_reg(const struct sr_usb_dev_inst *usb,
 	return ret;
 }
 
+SR_PRIV int lwla_read_long_reg(const struct sr_usb_dev_inst *usb,
+			       uint32_t addr, uint64_t *value)
+{
+	uint32_t low, high, dummy;
+	int ret;
+
+	ret = lwla_write_reg(usb, REG_LONG_ADDR, addr);
+	if (ret != SR_OK)
+		return ret;
+
+	ret = lwla_read_reg(usb, REG_LONG_STROBE, &dummy);
+	if (ret != SR_OK)
+		return ret;
+
+	ret = lwla_read_reg(usb, REG_LONG_HIGH, &high);
+	if (ret != SR_OK)
+		return ret;
+
+	ret = lwla_read_reg(usb, REG_LONG_LOW, &low);
+	if (ret != SR_OK)
+		return ret;
+
+	*value = ((uint64_t)high << 32) | low;
+
+	return SR_OK;
+}
+
 SR_PRIV int lwla_write_reg(const struct sr_usb_dev_inst *usb,
 			   uint16_t reg, uint32_t value)
 {
diff --git a/src/hardware/sysclk-lwla/lwla.h b/src/hardware/sysclk-lwla/lwla.h
index 867ed6a4..3e145255 100644
--- a/src/hardware/sysclk-lwla/lwla.h
+++ b/src/hardware/sysclk-lwla/lwla.h
@@ -114,6 +114,9 @@ SR_PRIV int lwla_receive_reply(const struct sr_usb_dev_inst *usb,
 SR_PRIV int lwla_read_reg(const struct sr_usb_dev_inst *usb,
 			  uint16_t reg, uint32_t *value);
 
+SR_PRIV int lwla_read_long_reg(const struct sr_usb_dev_inst *usb,
+			       uint32_t addr, uint64_t *value);
+
 SR_PRIV int lwla_write_reg(const struct sr_usb_dev_inst *usb,
 			   uint16_t reg, uint32_t value);
 
diff --git a/src/hardware/sysclk-lwla/protocol.c b/src/hardware/sysclk-lwla/protocol.c
index 5a1522fc..ff61a8b3 100644
--- a/src/hardware/sysclk-lwla/protocol.c
+++ b/src/hardware/sysclk-lwla/protocol.c
@@ -700,9 +700,9 @@ static void LIBUSB_CALL receive_transfer_in(struct libusb_transfer *transfer)
  */
 SR_PRIV int lwla_init_device(const struct sr_dev_inst *sdi)
 {
+	uint64_t value;
 	struct dev_context *devc;
 	int ret;
-	uint32_t value;
 
 	devc = sdi->priv;
 
@@ -710,36 +710,23 @@ SR_PRIV int lwla_init_device(const struct sr_dev_inst *sdi)
 	devc->cur_clock_config = CONF_CLOCK_NONE;
 
 	ret = lwla_set_clock_config(sdi);
-
 	if (ret != SR_OK)
 		return ret;
 
-	ret = lwla_write_reg(sdi->conn, REG_LONG_ADDR, 100);
+	ret = lwla_read_long_reg(sdi->conn, 100, &value);
 	if (ret != SR_OK)
 		return ret;
 
-	ret = lwla_read_reg(sdi->conn, REG_LONG_STROBE, &value);
+	/* Ignore the value returned by the first read */
+	ret = lwla_read_long_reg(sdi->conn, 100, &value);
 	if (ret != SR_OK)
 		return ret;
-	sr_dbg("Received test word 0x%08X back.", value);
-	if (value != 0x12345678)
-		return SR_ERR;
 
-	ret = lwla_read_reg(sdi->conn, REG_LONG_HIGH, &value);
-	if (ret != SR_OK)
-		return ret;
-	sr_dbg("Received test word 0x%08X back.", value);
-	if (value != 0x12345678)
+	if (value != UINT64_C(0x1234567887654321)) {
+		sr_err("Received invalid test word 0x%16" PRIX64 ".", value);
 		return SR_ERR;
-
-	ret = lwla_read_reg(sdi->conn, REG_LONG_LOW, &value);
-	if (ret != SR_OK)
-		return ret;
-	sr_dbg("Received test word 0x%08X back.", value);
-	if (value != 0x87654321)
-		return SR_ERR;
-
-	return ret;
+	}
+	return SR_OK;
 }
 
 /* Select the LWLA clock configuration.  If the clock source changed from