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)