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@xxxxxxxxx> --- drivers/usb/class/usbtmc.c | 85 +++++++++++++++++++++++++++++----------------- 1 file changed, 54 insertions(+), 31 deletions(-) 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 @@ 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) -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
