[alsa-devel] [PATCH v1 3/4] ASoC: codecs: pcm179x: Add reset gpio
Mylène Josserand
mylene.josserand at bootlin.com
Thu Mar 1 09:13:47 CET 2018
Hello Fabio,
Thank you for the review!
On Tue, 27 Feb 2018 19:30:11 -0300
Fabio Estevam <festevam at gmail.com> wrote:
> On Tue, Feb 27, 2018 at 6:24 PM, Mylène Josserand
> <mylene.josserand at bootlin.com> wrote:
>
> > + pcm179x->reset = of_get_named_gpio(np, "reset-gpios", 0);
> > + if (gpio_is_valid(pcm179x->reset)) {
> > + ret = devm_gpio_request_one(dev, pcm179x->reset,
> > + GPIOF_OUT_INIT_LOW,
> > + "pcm179x reset");
> > + if (ret) {
> > + dev_err(dev,
> > + "Failed to request GPIO %d as reset pin, error %d\n",
> > + pcm179x->reset, ret);
> > + return ret;
> > + }
> > +
> > + gpio_set_value(pcm179x->reset, 1);
>
> It would be better to use the gpiod API, which takes the GPIO polarity
> into account.
>
> There may be systems that have an inverter connected to this pin, and
> this can be changed in dts via GPIO_ACTIVE_HIGH.
Oh, true, I should have used gpiod. Thanks for pointing me out.
>
> Also, as the reset pin can be connected to an I2C expander, for
> example, so it is safer to use the cansleep variant:
>
> gpiod_set_value_cansleep(pcm179x->reset, 0);
Sure, I will update it.
Thanks,
Mylène
--
Mylène Josserand, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
http://bootlin.com
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