diff options
author | Alexandre Peixoto Ferreira <alexandref75@gmail.com> | 2013-04-30 00:51:51 -0500 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-05-16 17:50:50 -0700 |
commit | 88d9b2b38c99d7d7f5eb557a56b6aaeaa392df86 (patch) | |
tree | 746e33f9d4f26ed73bc76ba42a836a238faa5ba3 /drivers | |
parent | 8402db5dda3ac167014c143a633efff340aaff5b (diff) | |
download | linux-88d9b2b38c99d7d7f5eb557a56b6aaeaa392df86.tar.bz2 |
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>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/usb/class/usbtmc.c | 85 |
1 files changed, 54 insertions, 31 deletions
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index c450b047e365..9c370427d2ef 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) |