USB: usbtmc: TMC request code segregated from usbtmc_read
These patches implement a modification of the USBTMC
protocol to allow operation with Rigol equipment. The TMC request portion of
the code in function usbtmc_read is segregated to a function
send_request_dev_dep_msg_in as implemented by tommie in
https://github.com/tommie/linux/blob/usbtmc-rigol/drivers/usb/class/usbtmc.c
allowing the reuse later.
Signed-off-by: Alexandre Peixoto Ferreira <alexandref75@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index c450b04..9c37042 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -375,6 +375,59 @@
return rv;
}
+/*
+ * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
+ * @transfer_size: number of bytes to request from the device.
+ *
+ * See the USBTMC specification, Table 4.
+ *
+ * Also updates bTag_last_write.
+ */
+static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
+{
+ int retval;
+ u8 buffer[USBTMC_HEADER_SIZE];
+ int actual;
+
+ /* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
+ * Refer to class specs for details
+ */
+ buffer[0] = 2;
+ buffer[1] = data->bTag;
+ buffer[2] = ~(data->bTag);
+ buffer[3] = 0; /* Reserved */
+ buffer[4] = (transfer_size) & 255;
+ buffer[5] = ((transfer_size) >> 8) & 255;
+ buffer[6] = ((transfer_size) >> 16) & 255;
+ buffer[7] = ((transfer_size) >> 24) & 255;
+ buffer[8] = data->TermCharEnabled * 2;
+ /* Use term character? */
+ buffer[9] = data->TermChar;
+ buffer[10] = 0; /* Reserved */
+ buffer[11] = 0; /* Reserved */
+
+ /* Send bulk URB */
+ retval = usb_bulk_msg(data->usb_dev,
+ usb_sndbulkpipe(data->usb_dev,
+ data->bulk_out),
+ buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
+
+ /* Store bTag (in case we need to abort) */
+ data->bTag_last_write = data->bTag;
+
+ /* Increment bTag -- and increment again if zero */
+ data->bTag++;
+ if (!data->bTag)
+ (data->bTag)++;
+
+ if (retval < 0) {
+ dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
+ return retval;
+ }
+
+ return 0;
+}
+
static ssize_t usbtmc_read(struct file *filp, char __user *buf,
size_t count, loff_t *f_pos)
{
@@ -411,37 +464,7 @@
else
this_part = remaining;
- /* Setup IO buffer for DEV_DEP_MSG_IN message
- * Refer to class specs for details
- */
- buffer[0] = 2;
- buffer[1] = data->bTag;
- buffer[2] = ~(data->bTag);
- buffer[3] = 0; /* Reserved */
- buffer[4] = (this_part) & 255;
- buffer[5] = ((this_part) >> 8) & 255;
- buffer[6] = ((this_part) >> 16) & 255;
- buffer[7] = ((this_part) >> 24) & 255;
- buffer[8] = data->TermCharEnabled * 2;
- /* Use term character? */
- buffer[9] = data->TermChar;
- buffer[10] = 0; /* Reserved */
- buffer[11] = 0; /* Reserved */
-
- /* Send bulk URB */
- retval = usb_bulk_msg(data->usb_dev,
- usb_sndbulkpipe(data->usb_dev,
- data->bulk_out),
- buffer, 12, &actual, USBTMC_TIMEOUT);
-
- /* Store bTag (in case we need to abort) */
- data->bTag_last_write = data->bTag;
-
- /* Increment bTag -- and increment again if zero */
- data->bTag++;
- if (!data->bTag)
- (data->bTag)++;
-
+ retval = send_request_dev_dep_msg_in(data, this_part);
if (retval < 0) {
dev_err(dev, "usb_bulk_msg returned %d\n", retval);
if (data->auto_abort)