Hi, On 17/11/2020 0.20, Viorel Suman (OSS) wrote: > From: Viorel Suman <viorel.suman@xxxxxxx> > > Using GPIO API seems not a way to go for the case > when the same reset GPIO is used to control several codecs. > For a such case we can use the "gpio-reset" driver > and the "shared" reset API to manage the reset GPIO - > to deassert the reset when the first codec is powered up > and assert it when there is no codec in use. > DTS is supposed to look as follows: > > / { > ak4458_reset: gpio-reset { > compatible = "gpio-reset"; > reset-gpios = <&pca6416 4 GPIO_ACTIVE_LOW>; > #reset-cells = <0>; > initially-in-reset; I can not find anything resembling to this in next-20201119. Where is the implementation and documentation for this gpio-reset? > }; > }; > > &i2c3 { > pca6416: gpio@20 { > compatible = "ti,tca6416"; > reg = <0x20>; > gpio-controller; > #gpio-cells = <2>; > }; > > ak4458_1: ak4458@10 { > compatible = "asahi-kasei,ak4458"; > reg = <0x10>; > resets = <&ak4458_reset>; > }; > > ak4458_2: ak4458@11 { > compatible = "asahi-kasei,ak4458"; > reg = <0x11>; > resets = <&ak4458_reset>; > }; > > ak4458_3: ak4458@12 { > compatible = "asahi-kasei,ak4458"; > reg = <0x12>; > resets = <&ak4458_reset>; > }; > }; > > Signed-off-by: Viorel Suman <viorel.suman@xxxxxxx> > --- > sound/soc/codecs/ak4458.c | 23 +++++++++++------------ > 1 file changed, 11 insertions(+), 12 deletions(-) > > diff --git a/sound/soc/codecs/ak4458.c b/sound/soc/codecs/ak4458.c > index 1010c9ee2e83..f27727cb1382 100644 > --- a/sound/soc/codecs/ak4458.c > +++ b/sound/soc/codecs/ak4458.c > @@ -13,6 +13,7 @@ > #include <linux/of_gpio.h> > #include <linux/pm_runtime.h> > #include <linux/regulator/consumer.h> > +#include <linux/reset.h> > #include <linux/slab.h> > #include <sound/initval.h> > #include <sound/pcm_params.h> > @@ -45,7 +46,7 @@ struct ak4458_priv { > const struct ak4458_drvdata *drvdata; > struct device *dev; > struct regmap *regmap; > - struct gpio_desc *reset_gpiod; > + struct reset_control *reset; > struct gpio_desc *mute_gpiod; > int digfil; /* SSLOW, SD, SLOW bits */ > int fs; /* sampling rate */ > @@ -597,17 +598,17 @@ static struct snd_soc_dai_driver ak4497_dai = { > > static void ak4458_power_off(struct ak4458_priv *ak4458) > { > - if (ak4458->reset_gpiod) { > - gpiod_set_value_cansleep(ak4458->reset_gpiod, 0); > - usleep_range(1000, 2000); > + if (ak4458->reset) { > + reset_control_assert(ak4458->reset); > + msleep(20); > } > } > > static void ak4458_power_on(struct ak4458_priv *ak4458) > { > - if (ak4458->reset_gpiod) { > - gpiod_set_value_cansleep(ak4458->reset_gpiod, 1); > - usleep_range(1000, 2000); > + if (ak4458->reset) { > + reset_control_deassert(ak4458->reset); > + msleep(20); > } > } > > @@ -685,7 +686,6 @@ static int __maybe_unused ak4458_runtime_resume(struct device *dev) > if (ak4458->mute_gpiod) > gpiod_set_value_cansleep(ak4458->mute_gpiod, 1); > > - ak4458_power_off(ak4458); > ak4458_power_on(ak4458); > > regcache_cache_only(ak4458->regmap, false); > @@ -771,10 +771,9 @@ static int ak4458_i2c_probe(struct i2c_client *i2c) > > ak4458->drvdata = of_device_get_match_data(&i2c->dev); > > - ak4458->reset_gpiod = devm_gpiod_get_optional(ak4458->dev, "reset", > - GPIOD_OUT_LOW); > - if (IS_ERR(ak4458->reset_gpiod)) > - return PTR_ERR(ak4458->reset_gpiod); > + ak4458->reset = devm_reset_control_get_optional_shared(ak4458->dev, NULL); > + if (IS_ERR(ak4458->reset)) > + return PTR_ERR(ak4458->reset); The binding documentation must be updated and you must support the gpio way as well. When I had this discussion around using the reset framework for shared enable and/or reset pins it was suggested that _if_ such a driver makes sense then it should internally handle (by using magic strings) the fallback and work with pre-reset binding. > > ak4458->mute_gpiod = devm_gpiod_get_optional(ak4458->dev, "mute", > GPIOD_OUT_LOW); > - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki