Hi Dmitry,
On 30.06.2015 02:08, Dmitry Torokhov wrote:
On Wed, Jun 24, 2015 at 07:18:38AM +0200, Dirk Behme wrote:
On 17.06.2015 01:57, Dmitry Torokhov wrote:
On Mon, Jun 15, 2015 at 07:54:25AM +0200, Dirk Behme wrote:
From: Knut Wohlrab <Knut.Wohlrab@xxxxxxxxxxxx>
According to
Documentation/devicetree/bindings/input/touchscreen/zforce_ts.txt
the RST GPIO is supposed to provide a polarity flag parameter
gpios = <&GPIO_BANK GPIO_NUMBER GPIO_POLARITY>
with GPIO_POLARITY
reset active low = 1 (GPIO_ACTIVE_LOW)
reset active high = 0 (GPIO_ACTIVE_HIGH)
Example for GPIO_ACTIVE_LOW (1) reset GPIO:
zforce_ts@50 { /* Neonode zForce I2C */
compatible = "neonode,zforce-ts";
...
gpios = <&gpio6 14 GPIO_ACTIVE_HIGH>, /* INT */
<&gpio1 29 GPIO_ACTIVE_LOW>; /* RST */
...
};
Add the missing polarity flag evaluation to the driver.
Signed-off-by: Knut Wohlrab <Knut.Wohlrab@xxxxxxxxxxxx>
Signed-off-by: Oleksij Rempel <external.Oleksij.Rempel@xxxxxxxxxxxx>
Signed-off-by: Dirk Behme <dirk.behme@xxxxxxxxxxxx>
---
drivers/input/touchscreen/zforce_ts.c | 27 +++++++++++++++++++++++----
include/linux/platform_data/zforce_ts.h | 3 +++
2 files changed, 26 insertions(+), 4 deletions(-)
diff --git a/drivers/input/touchscreen/zforce_ts.c b/drivers/input/touchscreen/zforce_ts.c
index 19880c7..125311d 100644
--- a/drivers/input/touchscreen/zforce_ts.c
+++ b/drivers/input/touchscreen/zforce_ts.c
@@ -162,6 +162,20 @@ static int zforce_command(struct zforce_ts *ts, u8 cmd)
return 0;
}
+static void zforce_reset_assert(struct zforce_ts *ts)
+{
+ const struct zforce_ts_platdata *pdata = ts->pdata;
+
+ gpio_set_value(pdata->gpio_rst, pdata->reset_active_low ? 0 : 1);
Instead of doing this I'd rather we converted the driver to use gpiod
that handles polarity automatically.
Thanks, we'll look into that.
Just to understand correctly: Converting this driver to gpiod will
be an additional patch on top of this patch as it doesn't change any
functionality provided by this patch, but does some clean up.
Correct?
No, gpiod understands annotations on gpio descriptions and converts the
logical "active"/"inactive" value into appropriate output depending on
the polarity specified for gpio. So zforce_reset_assert() woudl only
need to do
gpiod_set_value[_cansleep](ts->gpio_rst, 1);
Yes, this is understood. But my question has been a different one ;) Let
me rephrase it:
Based on the existing driver this patch adds support for the (missing)
GPIO polarity on the reset pin. Based on the existing GPIO framework
used by the driver. Not talking about gpiod for the moment, I hope this
is fine (?).
Then, you've asked to convert the driver to gpiod. That's fine, too. And
will make the driver cleaner. And yes, it will handle the polarity, too.
With this, my proposal is to have two patches:
1) the existing one adding the polarity based on the existing GPIO
framework (handling the polarity 'manually')
2) converting the driver to gpiod, handling the polarity implicitly, then.
I'd propose to have 2 patches as described above as it would separate
the additional functionality (patch #1) and the gpiod framework change
(patch #2).
So my question is about the structuring of the patches, not about
details of gpiod_xxx().
Best regards
Dirk
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