From: Steve Longerbeam <slongerbeam@gmail.com>
To: Linus Walleij <linus.walleij@linaro.org>, LW@KARO-electronics.de
Cc: Shawn Guo <shawnguo@kernel.org>,
Sascha Hauer <kernel@pengutronix.de>,
Fabio Estevam <fabio.estevam@nxp.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Russell King <linux@armlinux.org.uk>,
Alexandre Courbot <gnurou@gmail.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Greg KH <gregkh@linuxfoundation.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
"devel@driverdev.osuosl.org" <devel@driverdev.osuosl.org>
Subject: Re: [PATCH 10/20] gpio: pca953x: Add optional reset gpio control
Date: Fri, 30 Dec 2016 10:03:53 -0800 [thread overview]
Message-ID: <9fa1db80-b0ea-68af-c122-49ea0b4315ec@gmail.com> (raw)
In-Reply-To: <CACRpkdZG2j4_LwP8KUVBTOtXma75YvYtC6CW1QqYwOm-MOZgHg@mail.gmail.com>
Hi Linus, Lothar,
On 12/30/2016 05:17 AM, Linus Walleij wrote:
> On Thu, Dec 29, 2016 at 11:27 PM, Steve Longerbeam
> <slongerbeam@gmail.com> wrote:
>
>> Add optional reset-gpios pin control. If present, de-assert the
>> specified reset gpio pin to bring the chip out of reset.
>>
>> Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
>> Cc: Linus Walleij <linus.walleij@linaro.org>
>> Cc: Alexandre Courbot <gnurou@gmail.com>
>> Cc: linux-gpio@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
> This seems like a separate patch from the other 19 patches so please send it
> separately so I can handle logistics easier in the future.
Ok, I'll send the next version separately.
>
>
>> @@ -133,6 +134,7 @@ struct pca953x_chip {
>> const char *const *names;
>> unsigned long driver_data;
>> struct regulator *regulator;
>> + struct gpio_desc *reset_gpio;
> Why do you even keep this around in the device state container?
>
> As you only use it in the probe() function, use a local variable.
>
> The descriptor will be free():ed by the devm infrastructure anyways.
I think my reasoning for putting the gpio handle into the device
struct was for possibly using it for run-time reset control at some
point. But that could be done later if needed, so I'll go ahead and
make it local.
>> + /* see if we need to de-assert a reset pin */
>> + chip->reset_gpio = devm_gpiod_get_optional(&client->dev,
>> + "reset",
>> + GPIOD_OUT_LOW);
>> + if (IS_ERR(chip->reset_gpio)) {
>> + dev_err(&client->dev, "request for reset pin failed\n");
>> + return PTR_ERR(chip->reset_gpio);
>> + }
> Nice.
>
>> + if (chip->reset_gpio) {
>> + /* bring chip out of reset */
>> + dev_info(&client->dev, "releasing reset\n");
>> + gpiod_set_value(chip->reset_gpio, 0);
>> + }
> Is this really needed given that you set it low in the
> devm_gpiod_get_optional()?
Yep, this is left over from a previous iteration, but it isn't needed now.
I'll remove it.
Steve
next prev parent reply other threads:[~2016-12-30 18:03 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-29 22:27 [PATCH 00/20] i.MX Media Driver Steve Longerbeam
2016-12-29 22:27 ` [PATCH 01/20] ARM: dts: imx6qdl: Add compatible, clocks, irqs to MIPI CSI-2 node Steve Longerbeam
2016-12-29 22:27 ` [PATCH 02/20] ARM: dts: imx6qdl: Add mipi_ipu1/2 multiplexers, mipi_csi, and their connections Steve Longerbeam
2016-12-29 22:27 ` [PATCH 03/20] ARM: dts: imx6qdl: add media device Steve Longerbeam
2016-12-29 22:27 ` [PATCH 04/20] ARM: dts: imx6-sabrelite: add OV5642 and OV5640 camera sensors Steve Longerbeam
2016-12-29 22:27 ` [PATCH 05/20] ARM: dts: imx6-sabresd: " Steve Longerbeam
2016-12-29 22:27 ` [PATCH 06/20] ARM: dts: imx6-sabreauto: create i2cmux for i2c3 Steve Longerbeam
2016-12-29 22:27 ` [PATCH 07/20] ARM: dts: imx6-sabreauto: add reset-gpios property for max7310_b Steve Longerbeam
2016-12-29 22:27 ` [PATCH 08/20] ARM: dts: imx6-sabreauto: add pinctrl for gpt input capture Steve Longerbeam
2016-12-29 22:27 ` [PATCH 09/20] ARM: dts: imx6-sabreauto: add the ADV7180 video decoder Steve Longerbeam
2016-12-29 22:27 ` [PATCH 10/20] gpio: pca953x: Add optional reset gpio control Steve Longerbeam
2016-12-30 7:06 ` Lothar Waßmann
2016-12-30 13:17 ` Linus Walleij
2016-12-30 18:03 ` Steve Longerbeam [this message]
2016-12-29 22:27 ` [PATCH 11/20] media: Add i.MX media core driver Steve Longerbeam
2017-01-03 21:17 ` Rob Herring
2016-12-29 22:27 ` [PATCH 12/20] media: imx: Add CSI subdev driver Steve Longerbeam
2016-12-29 22:27 ` [PATCH 13/20] media: imx: Add SMFC " Steve Longerbeam
2016-12-29 22:27 ` [PATCH 14/20] media: imx: Add IC subdev drivers Steve Longerbeam
2016-12-29 22:27 ` [PATCH 15/20] media: imx: Add Camera Interface subdev driver Steve Longerbeam
2016-12-29 22:27 ` [PATCH 16/20] media: imx: Add MIPI CSI-2 Receiver " Steve Longerbeam
2016-12-29 22:27 ` [PATCH 17/20] media: imx: Add video switch " Steve Longerbeam
2016-12-29 22:27 ` [PATCH 18/20] media: imx: Add MIPI CSI-2 OV5640 sensor " Steve Longerbeam
2016-12-29 22:27 ` [PATCH 19/20] media: imx: Add Parallel OV5642 " Steve Longerbeam
2016-12-29 22:27 ` [PATCH 20/20] ARM: imx_v6_v7_defconfig: Enable staging video4linux drivers Steve Longerbeam
2017-01-02 21:09 ` [PATCH 00/20] i.MX Media Driver Fabio Estevam
2017-01-03 20:50 ` Steve Longerbeam
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