Messages in this thread | | | From | Linus Walleij <> | Date | Fri, 30 Dec 2016 14:17:38 +0100 | Subject | Re: [PATCH 10/20] gpio: pca953x: Add optional reset gpio control |
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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.
> @@ -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.
> + /* 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()?
Yours, Linus Walleij
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