Messages in this thread | | | Subject | Re: [PATCH v1 3/4] ASoC: tda7802: Add enable device attribute | From | Cezary Rojewski <> | Date | Wed, 12 Jun 2019 19:14:57 +0200 |
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On 2019-06-11 19:49, Thomas Preston wrote: > Add a device attribute to control the enable regulator. Write 1 to > enable, 0 to disable (ref-count minus one), or -1 to force disable the > physical pin. > > To disable a set of amplifiers wired to the same enable gpio, each > device must be disabled. For example: > > echo 0 > /sys/devices/.../device:00/enable > echo 0 > /sys/devices/.../device:01/enable > > In an emergency, we can force disable from any device: > > echo -1 > /sys/devices/.../device:00/enable > > Signed-off-by: Thomas Preston <thomas.preston@codethink.co.uk> > Cc: Patrick Glaser <pglaser@tesla.com> > Cc: Rob Duncan <rduncan@tesla.com> > Cc: Nate Case <ncase@tesla.com> > --- > sound/soc/codecs/tda7802.c | 65 +++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 64 insertions(+), 1 deletion(-) > > diff --git a/sound/soc/codecs/tda7802.c b/sound/soc/codecs/tda7802.c > index 38ca52de85f0..62aae011d9f1 100644 > --- a/sound/soc/codecs/tda7802.c > +++ b/sound/soc/codecs/tda7802.c > @@ -458,6 +458,42 @@ static struct snd_soc_dai_driver tda7802_dai_driver = { > .ops = &tda7802_dai_ops, > }; > > +static ssize_t enable_show(struct device *dev, struct device_attribute *attr, > + char *buf) > +{ > + struct tda7802_priv *tda7802 = dev_get_drvdata(dev); > + int enabled = regulator_is_enabled(tda7802->enable_reg) ? 1 : 0; > + > + return scnprintf(buf, PAGE_SIZE, "%d\n", enabled); > +} > + > +static ssize_t enable_store(struct device *dev, struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct tda7802_priv *tda7802 = dev_get_drvdata(dev); > + int err; > + > + if (sysfs_streq(buf, "1")) { > + err = regulator_enable(tda7802->enable_reg); > + if (err < 0) > + dev_err(dev, "Could not enable (sysfs)\n"); > + } else if (sysfs_streq(buf, "0")) { > + err = regulator_disable(tda7802->enable_reg); > + if (err < 0) > + dev_err(dev, "Could not disable (sysfs)\n"); > + } else if (sysfs_streq(buf, "-1")) { > + err = regulator_force_disable(tda7802->enable_reg); > + if (err < 0) > + dev_err(dev, "Could not force disable (sysfs)\n"); > + } else { > + return -EINVAL; > + } > + > + return count; > +} > + > +static DEVICE_ATTR_RW(enable); > + > /* read device tree or ACPI properties from device */ > static int tda7802_read_properties(struct tda7802_priv *tda7802) > { > @@ -493,7 +529,34 @@ static int tda7802_read_properties(struct tda7802_priv *tda7802) > return err; > } > > -static const struct snd_soc_component_driver tda7802_component_driver; > +static int tda7802_probe(struct snd_soc_component *component) > +{ > + struct tda7802_priv *tda7802 = snd_soc_component_get_drvdata(component); > + struct device *dev = &tda7802->i2c->dev; > + int err; > + > + dev_dbg(dev, "%s\n", __func__);
Function name alone ain't very informational. Is this intended?
> + > + err = device_create_file(dev, &dev_attr_enable); > + if (err < 0) { > + dev_err(dev, "Could not create enable attr\n"); > + return err; > + }
Regardless of outcome, you'll be returning err here. Consider leaving error message alone within if-statement. Remove redundant brackets if you decide to do so.
> + > + return err; > +} > + > +static void tda7802_remove(struct snd_soc_component *component) > +{ > + struct tda7802_priv *tda7802 = snd_soc_component_get_drvdata(component); > + > + device_remove_file(&tda7802->i2c->dev, &dev_attr_enable); > +} > + > +static const struct snd_soc_component_driver tda7802_component_driver = { > + .probe = tda7802_probe, > + .remove = tda7802_remove, > +}; > > static int tda7802_i2c_probe(struct i2c_client *i2c, > const struct i2c_device_id *id) >
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