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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-id: <5729A4AB.5080901@samsung.com>
Date:	Wed, 04 May 2016 09:28:43 +0200
From:	Jacek Anaszewski <j.anaszewski@...sung.com>
To:	Anders Darander <anders@...rgestorm.se>
Cc:	rpurdie@...ys.net, robh+dt@...nel.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-leds@...r.kernel.org,
	pawel.moll@....com, mark.rutland@....com,
	ijc+devicetree@...lion.org.uk, galak@...eaurora.org,
	Olliver Schinagl <oliver@...inagl.nl>,
	Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
Subject: Re: [PATCH] leds-pca963x: add bindings to invert polarity

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

On 05/02/2016 11:41 AM, Anders Darander wrote:
> Add a new DT property, nxp,inverted, to invert the polarity of the output.
>
> Tested on PCA9634.
>
> Signed-off-by: Anders Darander <anders@...rgestorm.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*/
>