* [PATCH] bw-qcam: use data_reverse instead of manually poking the control register
@ 2007-09-26 19:12 Brett Warden
2007-09-26 19:43 ` Ray Lee
2007-09-26 21:00 ` Randy Dunlap
0 siblings, 2 replies; 8+ messages in thread
From: Brett Warden @ 2007-09-26 19:12 UTC (permalink / raw)
To: linux-kernel; +Cc: trivial
Appeases the warning "parport0 (bw-qcam): use data_reverse for this!"
Signed-off-by: Brett T. Warden <brett.warden@gmail.com>
---
It seems to work fine with my Quickcam under 2.6.22.
diff --git a/drivers/media/video/bw-qcam.c b/drivers/media/video/bw-qcam.c
index 7d47cbe..01e47ed 100644
--- a/drivers/media/video/bw-qcam.c
+++ b/drivers/media/video/bw-qcam.c
@@ -107,6 +107,11 @@ static inline void write_lpcontrol(struct
qcam_device *q, int d)
parport_write_control(q->pport, d);
}
+static inline void reverse_port(struct qcam_device *q)
+{
+ parport_data_reverse(q->pport);
+}
+
static int qc_waithand(struct qcam_device *q, int val);
static int qc_command(struct qcam_device *q, int command);
static int qc_readparam(struct qcam_device *q);
@@ -369,7 +374,11 @@ static void qc_reset(struct qcam_device *q)
break;
case QC_ANY:
- write_lpcontrol(q, 0x20);
+ /*
+ * Replaced with reverse_port
+ * write_lpcontrol(q, 0x20);
+ */
+ reverse_port(q);
write_lpdata(q, 0x75);
if (read_lpdata(q) != 0x75) {
@@ -512,10 +521,12 @@ static inline int qc_readbytes(struct
qcam_device *q, char buffer[])
switch (q->port_mode & QC_MODE_MASK)
{
case QC_BIDIR: /* Bi-directional Port */
- write_lpcontrol(q, 0x26);
+ reverse_port(q);
+ write_lpcontrol(q, 0x6);
lo = (qc_waithand2(q, 1) >> 1);
hi = (read_lpstatus(q) >> 3) & 0x1f;
- write_lpcontrol(q, 0x2e);
+ reverse_port(q);
+ write_lpcontrol(q, 0xe);
lo2 = (qc_waithand2(q, 0) >> 1);
hi2 = (read_lpstatus(q) >> 3) & 0x1f;
switch (q->bpp)
@@ -613,10 +624,13 @@ static long qc_capture(struct qcam_device * q,
char __user *buf, unsigned long l
if ((q->port_mode & QC_MODE_MASK) == QC_BIDIR)
{
- write_lpcontrol(q, 0x2e); /* turn port around */
- write_lpcontrol(q, 0x26);
+ reverse_port(q); /* turn port around */
+ write_lpcontrol(q, 0xe);
+ reverse_port(q);
+ write_lpcontrol(q, 0x6);
(void) qc_waithand(q, 1);
- write_lpcontrol(q, 0x2e);
+ reverse_port(q);
+ write_lpcontrol(q, 0xe);
(void) qc_waithand(q, 0);
}
--
Brett Warden
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] bw-qcam: use data_reverse instead of manually poking the control register
2007-09-26 19:12 [PATCH] bw-qcam: use data_reverse instead of manually poking the control register Brett Warden
@ 2007-09-26 19:43 ` Ray Lee
2007-09-26 20:06 ` Brett Warden
2007-09-26 21:00 ` Randy Dunlap
1 sibling, 1 reply; 8+ messages in thread
From: Ray Lee @ 2007-09-26 19:43 UTC (permalink / raw)
To: Brett Warden; +Cc: linux-kernel, trivial
On 9/26/07, Brett Warden <brett.warden@gmail.com> wrote:
> Appeases the warning "parport0 (bw-qcam): use data_reverse for this!"
>
> Signed-off-by: Brett T. Warden <brett.warden@gmail.com>
>
> ---
>
> It seems to work fine with my Quickcam under 2.6.22.
> @@ -369,7 +374,11 @@ static void qc_reset(struct qcam_device *q)
> break;
>
> case QC_ANY:
> - write_lpcontrol(q, 0x20);
> + /*
> + * Replaced with reverse_port
> + * write_lpcontrol(q, 0x20);
> + */
> + reverse_port(q);
> write_lpdata(q, 0x75);
>
> if (read_lpdata(q) != 0x75) {
Just as an aside, if you've tested this and it works, then there's no
point to keep the write_lpcontrol even as a comment. Kill those four
lines, and if someone's interested in what happened they'll just look
at the file history.
Ray
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] bw-qcam: use data_reverse instead of manually poking the control register
2007-09-26 19:43 ` Ray Lee
@ 2007-09-26 20:06 ` Brett Warden
2007-09-26 21:00 ` Ray Lee
0 siblings, 1 reply; 8+ messages in thread
From: Brett Warden @ 2007-09-26 20:06 UTC (permalink / raw)
To: Ray Lee; +Cc: linux-kernel, trivial
On 9/26/07, Ray Lee <ray-lk@madrabbit.org> wrote:
> Just as an aside, if you've tested this and it works, then there's no
> point to keep the write_lpcontrol even as a comment. Kill those four
> lines, and if someone's interested in what happened they'll just look
> at the file history.
Point taken, thanks for the feedback.
---
diff --git a/drivers/media/video/bw-qcam.c b/drivers/media/video/bw-qcam.c
index 7d47cbe..0ba92e3 100644
--- a/drivers/media/video/bw-qcam.c
+++ b/drivers/media/video/bw-qcam.c
@@ -107,6 +107,11 @@ static inline void write_lpcontrol(struct
qcam_device *q, int d)
parport_write_control(q->pport, d);
}
+static inline void reverse_port(struct qcam_device *q)
+{
+ parport_data_reverse(q->pport);
+}
+
static int qc_waithand(struct qcam_device *q, int val);
static int qc_command(struct qcam_device *q, int command);
static int qc_readparam(struct qcam_device *q);
@@ -369,7 +374,7 @@ static void qc_reset(struct qcam_device *q)
break;
case QC_ANY:
- write_lpcontrol(q, 0x20);
+ reverse_port(q);
write_lpdata(q, 0x75);
if (read_lpdata(q) != 0x75) {
@@ -512,10 +517,12 @@ static inline int qc_readbytes(struct
qcam_device *q, char buffer[])
switch (q->port_mode & QC_MODE_MASK)
{
case QC_BIDIR: /* Bi-directional Port */
- write_lpcontrol(q, 0x26);
+ reverse_port(q);
+ write_lpcontrol(q, 0x6);
lo = (qc_waithand2(q, 1) >> 1);
hi = (read_lpstatus(q) >> 3) & 0x1f;
- write_lpcontrol(q, 0x2e);
+ reverse_port(q);
+ write_lpcontrol(q, 0xe);
lo2 = (qc_waithand2(q, 0) >> 1);
hi2 = (read_lpstatus(q) >> 3) & 0x1f;
switch (q->bpp)
@@ -613,10 +620,13 @@ static long qc_capture(struct qcam_device * q,
char __user *buf, unsigned long l
if ((q->port_mode & QC_MODE_MASK) == QC_BIDIR)
{
- write_lpcontrol(q, 0x2e); /* turn port around */
- write_lpcontrol(q, 0x26);
+ reverse_port(q); /* turn port around */
+ write_lpcontrol(q, 0xe);
+ reverse_port(q);
+ write_lpcontrol(q, 0x6);
(void) qc_waithand(q, 1);
- write_lpcontrol(q, 0x2e);
+ reverse_port(q);
+ write_lpcontrol(q, 0xe);
(void) qc_waithand(q, 0);
}
--
Brett Warden
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] bw-qcam: use data_reverse instead of manually poking the control register
2007-09-26 20:06 ` Brett Warden
@ 2007-09-26 21:00 ` Ray Lee
2007-09-26 21:43 ` Brett Warden
0 siblings, 1 reply; 8+ messages in thread
From: Ray Lee @ 2007-09-26 21:00 UTC (permalink / raw)
To: Brett Warden; +Cc: linux-kernel, trivial
On 9/26/07, Brett Warden <brett.warden@gmail.com> wrote:
> On 9/26/07, Ray Lee <ray-lk@madrabbit.org> wrote:
>
> > Just as an aside, if you've tested this and it works, then there's no
> > point to keep the write_lpcontrol even as a comment. Kill those four
> > lines, and if someone's interested in what happened they'll just look
> > at the file history.
>
> Point taken, thanks for the feedback.
>
> ---
>
> diff --git a/drivers/media/video/bw-qcam.c b/drivers/media/video/bw-qcam.c
> index 7d47cbe..0ba92e3 100644
> --- a/drivers/media/video/bw-qcam.c
> +++ b/drivers/media/video/bw-qcam.c
> @@ -107,6 +107,11 @@ static inline void write_lpcontrol(struct
> qcam_device *q, int d)
> parport_write_control(q->pport, d);
> }
>
> +static inline void reverse_port(struct qcam_device *q)
> +{
> + parport_data_reverse(q->pport);
> +}
> +
> static int qc_waithand(struct qcam_device *q, int val);
> static int qc_command(struct qcam_device *q, int command);
> static int qc_readparam(struct qcam_device *q);
> @@ -369,7 +374,7 @@ static void qc_reset(struct qcam_device *q)
> break;
>
> case QC_ANY:
> - write_lpcontrol(q, 0x20);
> + reverse_port(q);
> write_lpdata(q, 0x75);
>
> if (read_lpdata(q) != 0x75) {
> @@ -512,10 +517,12 @@ static inline int qc_readbytes(struct
> qcam_device *q, char buffer[])
> switch (q->port_mode & QC_MODE_MASK)
> {
> case QC_BIDIR: /* Bi-directional Port */
> - write_lpcontrol(q, 0x26);
> + reverse_port(q);
> + write_lpcontrol(q, 0x6);
> lo = (qc_waithand2(q, 1) >> 1);
> hi = (read_lpstatus(q) >> 3) & 0x1f;
> - write_lpcontrol(q, 0x2e);
> + reverse_port(q);
> + write_lpcontrol(q, 0xe);
> lo2 = (qc_waithand2(q, 0) >> 1);
> hi2 = (read_lpstatus(q) >> 3) & 0x1f;
> switch (q->bpp)
> @@ -613,10 +620,13 @@ static long qc_capture(struct qcam_device * q,
> char __user *buf, unsigned long l
>
> if ((q->port_mode & QC_MODE_MASK) == QC_BIDIR)
> {
> - write_lpcontrol(q, 0x2e); /* turn port around */
> - write_lpcontrol(q, 0x26);
> + reverse_port(q); /* turn port around */
> + write_lpcontrol(q, 0xe);
> + reverse_port(q);
> + write_lpcontrol(q, 0x6);
> (void) qc_waithand(q, 1);
> - write_lpcontrol(q, 0x2e);
> + reverse_port(q);
> + write_lpcontrol(q, 0xe);
> (void) qc_waithand(q, 0);
> }
Better, and do you have time for two (possibly stupid) questions? In
each of the last cases it looks like the transformation is from a
write_lpcontrol -> reverse_port and a write_lpcontrol (old address -
0x20). Except the first one, which merely has the reverse_port. One
would think that there should be a write_lpcontrol(q, 0x0); after that
one.
Also, is the reverse port sticky, or does it only apply to the next
write? If it's only the next, then maybe a different name would be
better. If it's sticky, then I think the code is wrong...
Ray
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] bw-qcam: use data_reverse instead of manually poking the control register
2007-09-26 19:12 [PATCH] bw-qcam: use data_reverse instead of manually poking the control register Brett Warden
2007-09-26 19:43 ` Ray Lee
@ 2007-09-26 21:00 ` Randy Dunlap
1 sibling, 0 replies; 8+ messages in thread
From: Randy Dunlap @ 2007-09-26 21:00 UTC (permalink / raw)
To: Brett Warden; +Cc: linux-kernel, trivial
On Wed, 26 Sep 2007 12:12:50 -0700 Brett Warden wrote:
> Appeases the warning "parport0 (bw-qcam): use data_reverse for this!"
>
> Signed-off-by: Brett T. Warden <brett.warden@gmail.com>
>
Where does the warning come from? (what software produces it?)
> ---
>
> It seems to work fine with my Quickcam under 2.6.22.
>
> diff --git a/drivers/media/video/bw-qcam.c b/drivers/media/video/bw-qcam.c
> index 7d47cbe..01e47ed 100644
> --- a/drivers/media/video/bw-qcam.c
> +++ b/drivers/media/video/bw-qcam.c
> @@ -107,6 +107,11 @@ static inline void write_lpcontrol(struct
> qcam_device *q, int d)
> parport_write_control(q->pport, d);
> }
>
> +static inline void reverse_port(struct qcam_device *q)
> +{
> + parport_data_reverse(q->pport);
> +}
> +
> static int qc_waithand(struct qcam_device *q, int val);
> static int qc_command(struct qcam_device *q, int command);
> static int qc_readparam(struct qcam_device *q);
> @@ -369,7 +374,11 @@ static void qc_reset(struct qcam_device *q)
> break;
>
> case QC_ANY:
> - write_lpcontrol(q, 0x20);
> + /*
> + * Replaced with reverse_port
> + * write_lpcontrol(q, 0x20);
> + */
> + reverse_port(q);
> write_lpdata(q, 0x75);
>
> if (read_lpdata(q) != 0x75) {
> @@ -512,10 +521,12 @@ static inline int qc_readbytes(struct
> qcam_device *q, char buffer[])
> switch (q->port_mode & QC_MODE_MASK)
> {
> case QC_BIDIR: /* Bi-directional Port */
> - write_lpcontrol(q, 0x26);
> + reverse_port(q);
> + write_lpcontrol(q, 0x6);
> lo = (qc_waithand2(q, 1) >> 1);
> hi = (read_lpstatus(q) >> 3) & 0x1f;
> - write_lpcontrol(q, 0x2e);
> + reverse_port(q);
> + write_lpcontrol(q, 0xe);
> lo2 = (qc_waithand2(q, 0) >> 1);
> hi2 = (read_lpstatus(q) >> 3) & 0x1f;
> switch (q->bpp)
> @@ -613,10 +624,13 @@ static long qc_capture(struct qcam_device * q,
> char __user *buf, unsigned long l
>
> if ((q->port_mode & QC_MODE_MASK) == QC_BIDIR)
> {
> - write_lpcontrol(q, 0x2e); /* turn port around */
> - write_lpcontrol(q, 0x26);
> + reverse_port(q); /* turn port around */
> + write_lpcontrol(q, 0xe);
> + reverse_port(q);
> + write_lpcontrol(q, 0x6);
> (void) qc_waithand(q, 1);
> - write_lpcontrol(q, 0x2e);
> + reverse_port(q);
> + write_lpcontrol(q, 0xe);
> (void) qc_waithand(q, 0);
> }
>
>
>
> --
---
~Randy
Phaedrus says that Quality is about caring.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] bw-qcam: use data_reverse instead of manually poking the control register
2007-09-26 21:00 ` Ray Lee
@ 2007-09-26 21:43 ` Brett Warden
2007-09-27 19:28 ` Brett Warden
0 siblings, 1 reply; 8+ messages in thread
From: Brett Warden @ 2007-09-26 21:43 UTC (permalink / raw)
To: Ray Lee, Randy Dunlap; +Cc: linux-kernel, trivial
On 9/26/07, Ray Lee <ray-lk@madrabbit.org> wrote:
> On 9/26/07, Brett Warden <brett.warden@gmail.com> wrote:
> > On 9/26/07, Ray Lee <ray-lk@madrabbit.org> wrote:
> >
> > > Just as an aside, if you've tested this and it works, then there's no
> > > point to keep the write_lpcontrol even as a comment. Kill those four
> > > lines, and if someone's interested in what happened they'll just look
> > > at the file history.
> >
> > Point taken, thanks for the feedback.
> >
> > ---
> >
> > diff --git a/drivers/media/video/bw-qcam.c b/drivers/media/video/bw-qcam.c
> > index 7d47cbe..0ba92e3 100644
> > --- a/drivers/media/video/bw-qcam.c
> > +++ b/drivers/media/video/bw-qcam.c
> > @@ -107,6 +107,11 @@ static inline void write_lpcontrol(struct
> > qcam_device *q, int d)
> > parport_write_control(q->pport, d);
> > }
> >
> > +static inline void reverse_port(struct qcam_device *q)
> > +{
> > + parport_data_reverse(q->pport);
> > +}
> > +
> > static int qc_waithand(struct qcam_device *q, int val);
> > static int qc_command(struct qcam_device *q, int command);
> > static int qc_readparam(struct qcam_device *q);
> > @@ -369,7 +374,7 @@ static void qc_reset(struct qcam_device *q)
> > break;
> >
> > case QC_ANY:
> > - write_lpcontrol(q, 0x20);
> > + reverse_port(q);
> > write_lpdata(q, 0x75);
> >
> > if (read_lpdata(q) != 0x75) {
> > @@ -512,10 +517,12 @@ static inline int qc_readbytes(struct
> > qcam_device *q, char buffer[])
> > switch (q->port_mode & QC_MODE_MASK)
> > {
> > case QC_BIDIR: /* Bi-directional Port */
> > - write_lpcontrol(q, 0x26);
> > + reverse_port(q);
> > + write_lpcontrol(q, 0x6);
> > lo = (qc_waithand2(q, 1) >> 1);
> > hi = (read_lpstatus(q) >> 3) & 0x1f;
> > - write_lpcontrol(q, 0x2e);
> > + reverse_port(q);
> > + write_lpcontrol(q, 0xe);
> > lo2 = (qc_waithand2(q, 0) >> 1);
> > hi2 = (read_lpstatus(q) >> 3) & 0x1f;
> > switch (q->bpp)
> > @@ -613,10 +620,13 @@ static long qc_capture(struct qcam_device * q,
> > char __user *buf, unsigned long l
> >
> > if ((q->port_mode & QC_MODE_MASK) == QC_BIDIR)
> > {
> > - write_lpcontrol(q, 0x2e); /* turn port around */
> > - write_lpcontrol(q, 0x26);
> > + reverse_port(q); /* turn port around */
> > + write_lpcontrol(q, 0xe);
> > + reverse_port(q);
> > + write_lpcontrol(q, 0x6);
> > (void) qc_waithand(q, 1);
> > - write_lpcontrol(q, 0x2e);
> > + reverse_port(q);
> > + write_lpcontrol(q, 0xe);
> > (void) qc_waithand(q, 0);
> > }
>
> Better, and do you have time for two (possibly stupid) questions? In
> each of the last cases it looks like the transformation is from a
> write_lpcontrol -> reverse_port and a write_lpcontrol (old address -
> 0x20). Except the first one, which merely has the reverse_port. One
> would think that there should be a write_lpcontrol(q, 0x0); after that
> one.
>
> Also, is the reverse port sticky, or does it only apply to the next
> write? If it's only the next, then maybe a different name would be
> better. If it's sticky, then I think the code is wrong...
In response to Randy's and your questions, here's what I understand:
The error message comes from parport_pc_write_control in
include/linux/parport_pc.h, which is called by bw-qcam's
write_lpcontrol():
static __inline__ void parport_pc_write_control (struct parport *p,
unsigned char d)
{
const unsigned char wm = (PARPORT_CONTROL_STROBE |
PARPORT_CONTROL_AUTOFD |
PARPORT_CONTROL_INIT |
PARPORT_CONTROL_SELECT);
/* Take this out when drivers have adapted to newer interface. */
if (d & 0x20) {
printk (KERN_DEBUG "%s (%s): use data_reverse for this!\n",
p->name, p->cad->name);
parport_pc_data_reverse (p);
}
__parport_pc_frob_control (p, wm, d & wm);
}
The mask wm works out to 0x0f, so first it calls
parport_pc_data_reverse(), then masks off the high nibble with the
reverse flag and makes the regular call.
Looking at that more carefully, I'm not sure whether I need to add the
write_lpcontrol(q, 0) after the first call. Other than that, I believe
I'm following the same procedure.
As for whether data_reverse is sticky, I don't know... I'll see what I
can find out.
--
Brett Warden
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] bw-qcam: use data_reverse instead of manually poking the control register
2007-09-26 21:43 ` Brett Warden
@ 2007-09-27 19:28 ` Brett Warden
2007-09-27 21:29 ` Alan Cox
0 siblings, 1 reply; 8+ messages in thread
From: Brett Warden @ 2007-09-27 19:28 UTC (permalink / raw)
To: Ray Lee, Randy Dunlap; +Cc: linux-kernel, trivial
Fixes use of parport_write_control() to match the newer interface that
requires explicit parport_data_reverse() and parport_data_forward()
calls. This eliminates the following error message and restores the
original intended behavior:
parport0 (bw-qcam): use data_reverse for this!
Also increases threshold in qc_detect() from 300 to 400, as my camera
often results in a count of approx 330. Added a kernel error message
to indicate detection failure.
Signed-off-by: Brett T. Warden <brett.warden@gmail.com>
---
Thanks Ray and Randy for your comments, and for pointing out that I
needed to reset the port to forward mode!
diff --git a/drivers/media/video/bw-qcam.c b/drivers/media/video/bw-qcam.c
index 7d47cbe..961e377 100644
--- a/drivers/media/video/bw-qcam.c
+++ b/drivers/media/video/bw-qcam.c
@@ -104,6 +104,17 @@ static inline void write_lpdata(struct
qcam_device *q, int d)
static inline void write_lpcontrol(struct qcam_device *q, int d)
{
+ if(0x20 & d) {
+ /* Set bidirectional mode to reverse (data in) */
+ parport_data_reverse(q->pport);
+ } else {
+ /* Set bidirectional mode to forward (data out) */
+ parport_data_forward(q->pport);
+ }
+
+ /* Now issue the regular port command, but strip out the
+ * direction flag */
+ d &= ~0x20;
parport_write_control(q->pport, d);
}
@@ -344,10 +355,13 @@ static int qc_detect(struct qcam_device *q)
/* Be (even more) liberal in what you accept... */
/* if (count > 30 && count < 200) */
- if (count > 20 && count < 300)
+ if (count > 20 && count < 400)
+ {
return 1; /* found */
- else
+ } else {
+ printk(KERN_ERR "No Quickcam found on port %s\n",
q->pport->name);
return 0; /* not found */
+ }
}
--
Brett Warden
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] bw-qcam: use data_reverse instead of manually poking the control register
2007-09-27 19:28 ` Brett Warden
@ 2007-09-27 21:29 ` Alan Cox
0 siblings, 0 replies; 8+ messages in thread
From: Alan Cox @ 2007-09-27 21:29 UTC (permalink / raw)
To: Brett Warden; +Cc: Ray Lee, Randy Dunlap, linux-kernel, trivial
On Thu, 27 Sep 2007 12:28:31 -0700
"Brett Warden" <brett.warden@gmail.com> wrote:
> Fixes use of parport_write_control() to match the newer interface that
> requires explicit parport_data_reverse() and parport_data_forward()
> calls. This eliminates the following error message and restores the
> original intended behavior:
Looks good
> parport0 (bw-qcam): use data_reverse for this!
>
> Also increases threshold in qc_detect() from 300 to 400, as my camera
> often results in a count of approx 330. Added a kernel error message
> to indicate detection failure.
Likewise
> Signed-off-by: Brett T. Warden <brett.warden@gmail.com>
Acked-by: Alan Cox <alan@redhat.com>
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2007-09-27 21:25 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2007-09-26 19:12 [PATCH] bw-qcam: use data_reverse instead of manually poking the control register Brett Warden
2007-09-26 19:43 ` Ray Lee
2007-09-26 20:06 ` Brett Warden
2007-09-26 21:00 ` Ray Lee
2007-09-26 21:43 ` Brett Warden
2007-09-27 19:28 ` Brett Warden
2007-09-27 21:29 ` Alan Cox
2007-09-26 21:00 ` Randy Dunlap
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