Commit 88d9b2b3 authored by Alexandre Peixoto Ferreira's avatar Alexandre Peixoto Ferreira Committed by Greg Kroah-Hartman
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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: default avatarAlexandre Peixoto Ferreira <alexandref75@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8402db5d

drivers/usb/class/usbtmc.c

+54 −31
Original line number Diff line number Diff line
@@ -375,6 +375,59 @@ exit: 
	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 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf, 
		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)

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