[PATCH] leds-pca963x: add bindings to invert polarity

[Anders Darander]

Add a new DT property, nxp,inverted, to invert the polarity of the output.

Tested on PCA9634.

Signed-off-by: Anders Darander <and...@chargestorm.se>
---
Documentation/devicetree/bindings/leds/pca963x.txt | 1 +
drivers/leds/leds-pca963x.c | 17 +++++++++++++++--
include/linux/platform_data/leds-pca963x.h | 6 ++++++
3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/leds/pca963x.txt b/Documentation/devicetree/bindings/leds/pca963x.txt
index dafbe99..68579c5 100644
--- a/Documentation/devicetree/bindings/leds/pca963x.txt
+++ b/Documentation/devicetree/bindings/leds/pca963x.txt
@@ -7,6 +7,7 @@ Optional properties:
- nxp,totem-pole : use totem pole (push-pull) instead of open-drain (pca9632 defaults
to open-drain, newer chips to totem pole)
- nxp,hw-blink : use hardware blinking instead of software blinking
+- nxp,inverted: invert the polarity of the generated PWM

Each led is represented as a sub-node of the nxp,pca963x device.

diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
index 407eba1..41b7648 100644
--- a/drivers/leds/leds-pca963x.c
+++ b/drivers/leds/leds-pca963x.c
@@ -294,6 +294,12 @@ pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
else
pdata->blink_type = PCA963X_SW_BLINK;

+ /* default to non-inverted output, unless inverted is specified */
+ if (of_property_read_bool(np, "nxp,inverted"))
+ pdata->dir = PCA963X_INVERTED;
+ else
+ pdata->dir = PCA963X_NORMAL;
+
return pdata;
}

@@ -395,11 +401,18 @@ static int pca963x_probe(struct i2c_client *client,
i2c_smbus_write_byte_data(client, PCA963X_MODE1, 0x00);

if (pdata) {
+ u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
+ PCA963X_MODE2);
/* Configure output: open-drain or totem pole (push-pull) */
if (pdata->outdrv == PCA963X_OPEN_DRAIN)
- i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x01);
+ mode2 |= 0x01;
else
- i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x05);
+ mode2 |= 0x05;
+ /* Configure direction: normal or inverted */
+ if (pdata->dir == PCA963X_INVERTED)
+ mode2 |= 0x10;
+ i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
+ mode2);
}

return 0;
diff --git a/include/linux/platform_data/leds-pca963x.h b/include/linux/platform_data/leds-pca963x.h
index e731f00..54e845f 100644
--- a/include/linux/platform_data/leds-pca963x.h
+++ b/include/linux/platform_data/leds-pca963x.h
@@ -33,10 +33,16 @@ enum pca963x_blink_type {
PCA963X_HW_BLINK,
};

+enum pca963x_direction {
+ PCA963X_NORMAL,
+ PCA963X_INVERTED,
+};
+
struct pca963x_platform_data {
struct led_platform_data leds;
enum pca963x_outdrv outdrv;
enum pca963x_blink_type blink_type;
+ enum pca963x_direction dir;
};

#endif /* __LINUX_PCA963X_H*/
--
2.8.1

[Jacek Anaszewski]

Hi Anders,

Thanks for the patch.
Please note that there has already been an attempt to add
the support for inverted output polarity to this driver and related
discussion [1]. This thread remains quiet for around two weeks.

Cc Olliver and Ricardo.

[1] https://lkml.org/lkml/2016/4/19/95

Best regards,
Jacek Anaszewski

[Anders Darander]

Hi,

Thanks for the info.

* Jacek Anaszewski <j.anas...@samsung.com> [160504 09:28]:

> Please note that there has already been an attempt to add
> the support for inverted output polarity to this driver and related
> discussion [1]. This thread remains quiet for around two weeks.

Ah, nice coincidence! Unfortunately, I made the work earlier than his
posting, otherwise I could have spent the time on somethinge else. ;)

Well, then I hope v2 of his patches comes along.

Cheers,
Anders

--
Anders Darander, Senior System Architect
ChargeStorm AB / eStorm AB

[Olliver Schinagl]

Hey Jacek,

On 04-05-16 09:55, Anders Darander wrote:
> Hi,
>
> Thanks for the info.
>
> * Jacek Anaszewski <j.anas...@samsung.com> [160504 09:28]:
>> Please note that there has already been an attempt to add
>> the support for inverted output polarity to this driver and related
>> discussion [1]. This thread remains quiet for around two weeks.
> Ah, nice coincidence! Unfortunately, I made the work earlier than his
> posting, otherwise I could have spent the time on somethinge else. ;)

Sorry to be so slacking with submitting this, I've been sitting on it
for 6 months now :) I just kept postponing in submitting it. But as they
say, great minds, and all that.

[Anders Darander]

Hi,

* Olliver Schinagl <oli...@schinagl.nl> [160504 10:10]:

Any news on a v2?

Otherwise, could we agree on a dt binding for the inverted output, and
look into merging that prior to the rest of the series? I'd like to get
rid of my local patch...

Cheers,
Anders

[Olliver Schinagl]

Hi Anders,

I almost forgotten about this bit, I'll read back on the mails and
check/verify my results/discussions from back then.

Thanks for bringing it up again!

Olliver

>
> Cheers,
> Anders