[PATCH] wm97xx-core: Report a phys for WM97xx touchscreens

[PATCH] wm97xx-core: Report a phys for WM97xx touchscreens

[Mark Brown]

phys is displayed in various diagnostic output so ensure that it is set
to something sensible.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
---
It'd be nice to get this merged into 2.6.26 since this is rather user visible
and given that this is a new driver there's no risk of regressions.

 drivers/input/touchscreen/wm97xx-core.c |    2 ++
 include/linux/wm97xx.h                  |    1 +
 2 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/input/touchscreen/wm97xx-core.c b/drivers/input/touchscreen/wm97xx-core.c
index e9c7ea4..12ae1ba 100644
--- a/drivers/input/touchscreen/wm97xx-core.c
+++ b/drivers/input/touchscreen/wm97xx-core.c
@@ -616,6 +616,8 @@ static int wm97xx_probe(struct device *dev)
 
 	/* set up touch configuration */
 	wm->input_dev->name = "wm97xx touchscreen";
+	snprintf(wm->phys, sizeof(wm->phys), "%s/input0", dev->bus_id);
+	wm->input_dev->phys = wm->phys;
 	wm->input_dev->open = wm97xx_ts_input_open;
 	wm->input_dev->close = wm97xx_ts_input_close;
 	set_bit(EV_ABS, wm->input_dev->evbit);
diff --git a/include/linux/wm97xx.h b/include/linux/wm97xx.h
index 4d13732..1f38fc4 100644
--- a/include/linux/wm97xx.h
+++ b/include/linux/wm97xx.h
@@ -261,6 +261,7 @@ struct wm97xx_mach_ops {
 };
 
 struct wm97xx {
+	char phys[32];			/* Device name */
 	u16 dig[3], id, gpio[6], misc;	/* Cached codec registers */
 	u16 dig_save[3];		/* saved during aux reading */
 	struct wm97xx_codec_drv *codec;	/* attached codec driver*/
-- 
1.5.3.2

Re: [PATCH] wm97xx-core: Report a phys for WM97xx touchscreens

[Dmitry Torokhov]

Hi Mark,

On Thu, May 22, 2008 at 12:35:06PM +0100, Mark Brown wrote:
> phys is displayed in various diagnostic output so ensure that it is set
> to something sensible.
>

Phys is used to describe the physical connection of a device that is
ideally not changing between reboots so having it set up based on
device's bus_id is not a best option I think.

What tools besides evbug use phys? They probably should display both
phys and sysfs paths (I will be changing evbug soon).

-- 
Dmitry

Re: [PATCH] wm97xx-core: Report a phys for WM97xx touchscreens

[Mark Brown]

On Thu, May 22, 2008 at 09:41:48AM -0400, Dmitry Torokhov wrote:
> On Thu, May 22, 2008 at 12:35:06PM +0100, Mark Brown wrote:

> > phys is displayed in various diagnostic output so ensure that it is set
> > to something sensible.

> Phys is used to describe the physical connection of a device that is
> ideally not changing between reboots so having it set up based on
> device's bus_id is not a best option I think.

It didn't seem terribly wonderful to me either but I saw that some other
drivers were doing the same thing so I assumed it was idiomatic.  A
quick survey of devices on my laptop suggets that it's getting filled in
with USB bus IDs for some devices.

For a WM97xx device it should actually be OK almost all the time - AC97
bus identifiers are fixed in hardware, there would only be a problem if
additional AC97 buses are added which is relatively unlikely, especially
in the embedded applications where the WM97xx devices get used.
However, if it's supposed to be OK to leave this null then that would be
better.

> What tools besides evbug use phys? They probably should display both
> phys and sysfs paths (I will be changing evbug soon).

It was actually evbug that prompted this - it prints a rather alarming
'Connected device: "foo", NULL' when phys is left empty.