From c769f85e2740ebe7e4c726632fed52818640faba Mon Sep 17 00:00:00 2001
From: H Hartley Sweeten <hsweeten@visionengravers.com>
Date: Thu, 25 Jul 2013 16:10:25 -0700
Subject: [PATCH] staging: comedi: usbdux: simplify initializing the ao urb
transfer_buffer
Remove the ugly casting of datap to the ao urb->transfer_buffer. The format
of the data in the buffer is simply.
[0] = # of channels to update (s->async->cmd.chanlist.len)
[1] = lsb of value for 1st channel to update
[2] = msb of value for 1st channel to update
[3] = 1st channel to update (depvriv->dac_commands[0])
If more than 1 channel is to be updated they are simply added to the buffer:
[4] = lsb of value for 2st channel to update
[5] = msb of value for 2st channel to update
[6] = 1st channel to update (depvriv->dac_commands[1])
etc.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/staging/comedi/drivers/usbdux.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/drivers/staging/comedi/drivers/usbdux.c b/drivers/staging/comedi/drivers/usbdux.c
index 1399305d739f..cb94964cc9ba 100644
--- a/drivers/staging/comedi/drivers/usbdux.c
+++ b/drivers/staging/comedi/drivers/usbdux.c
@@ -425,8 +425,10 @@ static void usbduxsub_ao_isoc_irq(struct urb *urb)
struct comedi_device *dev = urb->context;
struct comedi_subdevice *s = dev->write_subdev;
struct usbdux_private *devpriv = dev->private;
- int i, ret;
int8_t *datap;
+ int len;
+ int ret;
+ int i;
switch (urb->status) {
case 0:
@@ -484,9 +486,11 @@ static void usbduxsub_ao_isoc_irq(struct urb *urb)
return;
}
}
+
/* transmit data to the USB bus */
- ((uint8_t *) (urb->transfer_buffer))[0] =
- s->async->cmd.chanlist_len;
+ datap = urb->transfer_buffer;
+ len = s->async->cmd.chanlist_len;
+ *datap++ = len;
for (i = 0; i < s->async->cmd.chanlist_len; i++) {
unsigned int chan = devpriv->dac_commands[i];
short val;
@@ -498,12 +502,9 @@ static void usbduxsub_ao_isoc_irq(struct urb *urb)
COMEDI_CB_OVERFLOW);
}
/* pointer to the DA */
- datap =
- (&(((int8_t *) urb->transfer_buffer)[i * 3 + 1]));
- /* get the data from comedi */
- datap[0] = val;
- datap[1] = val >> 8;
- datap[2] = chan;
+ *datap++ = val & 0xff;
+ *datap++ = (val >> 8) & 0xff;
+ *datap++ = chan;
devpriv->ao_readback[chan] = val;
s->async->events |= COMEDI_CB_BLOCK;
--
2.34.1