Re: Please revert 3eea8b5d68c801fec788b411582b803463834752 as it breaks touchscreen on n900.

Dmitry Torokhov
2015-06-02T18:09:08Z

On Tue, Jun 02, 2015 at 10:58:45AM -0700, Dmitry Torokhov wrote:
> On Tue, Jun 02, 2015 at 11:44:47AM +0200, Maxime Ripard wrote:
> > On Mon, Jun 01, 2015 at 02:32:13PM -0700, Dmitry Torokhov wrote:
> > > On Mon, Jun 01, 2015 at 11:22:26PM +0200, Maxime Ripard wrote:
> > > > Hi Dmitry,
> > > >
> > > > On Mon, Jun 01, 2015 at 10:47:30AM -0700, Dmitry Torokhov wrote:
> > > > > -static u32 of_get_optional_u32(struct device_node *np,
> > > > > - const char *property)
> > > > > +static bool touchscreen_get_property_u32(struct device_node *np,
> > > > > + const char *property,
> > > > > + unsigned int default_value,
> > > > > + unsigned int *value)
> > > > > {
> > > > > u32 val = 0;
> > > > > + int error;
> > > > >
> > > > > - of_property_read_u32(np, property, &val);
> > > > > + error = of_property_read_u32(np, property, &val);
> > > > > + if (error) {
> > > > > + *value = default_value;
> > > > > + return false;
> > > > > + }
> > > > >
> > > > > - return val;
> > > > > + *value = val;
> > > > > + return true;
> > > >
> > > > This looks good.
> > > >
> > > > However, of_property_read_u32 already does the right thing here by not
> > > > update val if the property is not found.
> > >
> > > I know but it is not documented anywhere (as far as I know) so I'd
> > > rather not rely on the implementation detail that might change in the
> > > future. This is not a hot path so extra assignment should not hurt.
> >
> > It is actually: http://lxr.free-electrons.com/source/drivers/of/base.c#L1231
>
> OK, fair enough. But not for ACPI properties (and I think we should
> convert the parser to device_property_read_xxx() so it is usable
> everywhere).

By the way, the previous version was busted, this one should compile.

--
Dmitry

Input: improve parsing OF parameters for touchscreens

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

When applying touchscreen parameters specified in device tree let's make
sure we keep whatever setup was done by the driver and not reset the
missing values to zero.

Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
drivers/input/touchscreen/edt-ft5x06.c | 2 -
drivers/input/touchscreen/of_touchscreen.c | 69 ++++++++++++++++++----------
drivers/input/touchscreen/tsc2005.c | 2 -
include/linux/input/touchscreen.h | 5 +-
4 files changed, 49 insertions(+), 29 deletions(-)

diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index 29d179a..394b1de 100644
--- a/drivers/input/touchscreen/edt-ft5x06.c
+++ b/drivers/input/touchscreen/edt-ft5x06.c
@@ -1041,7 +1041,7 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
0, tsdata->num_y * 64 - 1, 0, 0);

if (!pdata)
- touchscreen_parse_of_params(input);
+ touchscreen_parse_of_params(input, true);

error = input_mt_init_slots(input, MAX_SUPPORT_POINTS, INPUT_MT_DIRECT);
if (error) {
diff --git a/drivers/input/touchscreen/of_touchscreen.c b/drivers/input/touchscreen/of_touchscreen.c
index b82b520..806cd0a 100644
--- a/drivers/input/touchscreen/of_touchscreen.c
+++ b/drivers/input/touchscreen/of_touchscreen.c
@@ -14,14 +14,22 @@
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>

-static u32 of_get_optional_u32(struct device_node *np,
- const char *property)
+static bool touchscreen_get_prop_u32(struct device_node *np,
+ const char *property,
+ unsigned int default_value,
+ unsigned int *value)
{
- u32 val = 0;
+ u32 val;
+ int error;

- of_property_read_u32(np, property, &val);
+ error = of_property_read_u32(np, property, &val);
+ if (error) {
+ *value = default_value;
+ return false;
+ }

- return val;
+ *value = val;
+ return true;
}

static void touchscreen_set_params(struct input_dev *dev,
@@ -54,34 +62,45 @@ static void touchscreen_set_params(struct input_dev *dev,
* input device accordingly. The function keeps previously setuped default
* values if no value is specified via DT.
*/
-void touchscreen_parse_of_params(struct input_dev *dev)
+void touchscreen_parse_of_params(struct input_dev *dev, bool multitouch)
{
struct device_node *np = dev->dev.parent->of_node;
- u32 maximum, fuzz;
+ unsigned int axis;
+ unsigned int maximum, fuzz;
+ bool data_present;

input_alloc_absinfo(dev);
if (!dev->absinfo)
return;

- maximum = of_get_optional_u32(np, "touchscreen-size-x");
- fuzz = of_get_optional_u32(np, "touchscreen-fuzz-x");
- if (maximum || fuzz) {
- touchscreen_set_params(dev, ABS_X, maximum, fuzz);
- touchscreen_set_params(dev, ABS_MT_POSITION_X, maximum, fuzz);
- }
+ axis = multitouch ? ABS_MT_POSITION_X : ABS_X;
+ data_present = touchscreen_get_prop_u32(np, "touchscreen-size-x",
+ input_abs_get_max(dev, axis),
+ &maximum) |
+ touchscreen_get_prop_u32(np, "touchscreen-fuzz-x",
+ input_abs_get_fuzz(dev, axis),
+ &fuzz);
+ if (data_present)
+ touchscreen_set_params(dev, axis, maximum, fuzz);

- maximum = of_get_optional_u32(np, "touchscreen-size-y");
- fuzz = of_get_optional_u32(np, "touchscreen-fuzz-y");
- if (maximum || fuzz) {
- touchscreen_set_params(dev, ABS_Y, maximum, fuzz);
- touchscreen_set_params(dev, ABS_MT_POSITION_Y, maximum, fuzz);
- }
+ axis = multitouch ? ABS_MT_POSITION_Y : ABS_Y;
+ data_present = touchscreen_get_prop_u32(np, "touchscreen-size-y",
+ input_abs_get_max(dev, axis),
+ &maximum) |
+ touchscreen_get_prop_u32(np, "touchscreen-fuzz-y",
+ input_abs_get_fuzz(dev, axis),
+ &fuzz);
+ if (data_present)
+ touchscreen_set_params(dev, axis, maximum, fuzz);

- maximum = of_get_optional_u32(np, "touchscreen-max-pressure");
- fuzz = of_get_optional_u32(np, "touchscreen-fuzz-pressure");
- if (maximum || fuzz) {
- touchscreen_set_params(dev, ABS_PRESSURE, maximum, fuzz);
- touchscreen_set_params(dev, ABS_MT_PRESSURE, maximum, fuzz);
- }
+ axis = multitouch ? ABS_MT_PRESSURE : ABS_PRESSURE;
+ data_present = touchscreen_get_prop_u32(np, "touchscreen-max-pressure",
+ input_abs_get_max(dev, axis),
+ &maximum) |
+ touchscreen_get_prop_u32(np, "touchscreen-fuzz-pressure",
+ input_abs_get_fuzz(dev, axis),
+ &fuzz);
+ if (data_present)
+ touchscreen_set_params(dev, axis, maximum, fuzz);
}
EXPORT_SYMBOL(touchscreen_parse_of_params);
diff --git a/drivers/input/touchscreen/tsc2005.c b/drivers/input/touchscreen/tsc2005.c
index 72657c5..d8c025b 100644
--- a/drivers/input/touchscreen/tsc2005.c
+++ b/drivers/input/touchscreen/tsc2005.c
@@ -709,7 +709,7 @@ static int tsc2005_probe(struct spi_device *spi)
input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);

if (np)
- touchscreen_parse_of_params(input_dev);
+ touchscreen_parse_of_params(input_dev, false);

input_dev->open = tsc2005_open;
input_dev->close = tsc2005_close;
diff --git a/include/linux/input/touchscreen.h b/include/linux/input/touchscreen.h
index 08a5ef6..eecc9ea 100644
--- a/include/linux/input/touchscreen.h
+++ b/include/linux/input/touchscreen.h
@@ -12,9 +12,10 @@
#include <linux/input.h>

#ifdef CONFIG_OF
-void touchscreen_parse_of_params(struct input_dev *dev);
+void touchscreen_parse_of_params(struct input_dev *dev, bool multitouch);
#else
-static inline void touchscreen_parse_of_params(struct input_dev *dev)
+static inline void touchscreen_parse_of_params(struct input_dev *dev,
+ bool multitouch)
{
}
#endif