From: Linus Walleij <linus.walleij@linaro.org>
To: Khouloud Touil <ktouil@baylibre.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
baylibre-upstreaming@groups.io,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
linux-i2c <linux-i2c@vger.kernel.org>
Subject: Re: [PATCH 2/4] nvmem: add support for the write-protect pin
Date: Fri, 22 Nov 2019 13:47:10 +0100 [thread overview]
Message-ID: <CACRpkdYwwHbjrSq7DRyCkD4jDXYoWFWNnUi-SkCZ5gUAkbxOZQ@mail.gmail.com> (raw)
In-Reply-To: <20191120142038.30746-3-ktouil@baylibre.com>
Hi Khouloud,
more comments!
On Wed, Nov 20, 2019 at 3:21 PM Khouloud Touil <ktouil@baylibre.com> wrote:
> + if (nvmem->reg_write) {
> + gpiod_set_value_cansleep(nvmem->wp_gpio, 0);
> + ret = nvmem->reg_write(nvmem->priv, offset, val, bytes);
> + gpiod_set_value_cansleep(nvmem->wp_gpio, 1);
> + return ret;
> + }
Since I requested that the GPIO line shall be flagged as
active low in the device tree, make sure to invert this
and toss in a comment:
/*
* We assert and deassert the write protection GPIO line.
* This line is often active low, but that semantic is handled
* in gpiolib in respons to flags in the machine description,
* such as the device tree or ACPI.
*/
gpiod_set_value_cansleep(nvmem->wp_gpio, 1);
ret = nvmem->reg_write(nvmem->priv, offset, val, bytes);
gpiod_set_value_cansleep(nvmem->wp_gpio, 0);
> @@ -365,6 +372,15 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
> kfree(nvmem);
> return ERR_PTR(rval);
> }
> + if (config->wp_gpio)
> + nvmem->wp_gpio = config->wp_gpio;
> + else
> + nvmem->wp_gpio = gpiod_get_optional(config->dev,
> + "wp",
> + GPIOD_OUT_HIGH);
GPIOD_OUT_LOW as it will be inverted.
Apart from this I like the idea in this patch!
Yours,
Linus Walleij
next prev parent reply other threads:[~2019-11-22 12:47 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-20 14:20 [PATCH 0/4] at24: move write-protect pin handling to nvmem core Khouloud Touil
2019-11-20 14:20 ` [PATCH 1/4] dt-bindings: nvmem: new optional property write-protect-gpios Khouloud Touil
2019-11-22 12:41 ` Linus Walleij
2019-11-22 12:47 ` Bartosz Golaszewski
2019-11-22 12:53 ` Linus Walleij
2019-11-22 13:04 ` Bartosz Golaszewski
2019-11-22 13:46 ` Linus Walleij
[not found] ` <CALL1Z1xpcGyh_f3ooRT+gGApoAnS7YBMd2hUKqnt+pTcAFoeAg@mail.gmail.com>
2019-11-28 13:44 ` Linus Walleij
2019-11-29 8:47 ` Bartosz Golaszewski
2019-12-04 15:14 ` Rob Herring
2019-11-22 13:10 ` Peter Rosin
2019-11-20 14:20 ` [PATCH 2/4] nvmem: add support for the write-protect pin Khouloud Touil
2019-11-22 12:47 ` Linus Walleij [this message]
2019-11-20 14:20 ` [PATCH 3/4] dt-bindings: at24: remove the optional property write-protect-gpios Khouloud Touil
2019-12-04 15:22 ` Rob Herring
2019-11-20 14:20 ` [PATCH 4/4] eeprom: at24: remove the write-protect pin support Khouloud Touil
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