[alsa-devel] [PATCH] ASoC: da7219: Allow pdata to specify a VDDIO

[Daniel Kurtz]

Some systems do not have software controllable regulators driving the
DA7219's supplies, nor can they use device tree to create "always-on fixed
regulators" to easily pretend like they do.

On these systems the call to devm_regulator_bulk_get() just creates
a set of dummy registers.  Calling regulator_get_voltage() on a dummy
regulator just returns -EINVAL, in which case the DA7219 is always set up
to use the default VDDIO voltage range of 2.5-3.6V.

Provide a new device property to let such systems specify a different
VDDIO if needed (e.g., 1.8V).

Signed-off-by: Daniel Kurtz <djkurtz at chromium.org>
---

This patch tries to solve the same problem as in the following patches,
but does so in a way that doesn't require registering fixed regulators in
the audio machine-driver:
  https://patchwork.kernel.org/patch/10531097 & 10531099
  https://patchwork.kernel.org/patch/10536023/

 include/sound/da7219.h    |  2 ++
 sound/soc/codecs/da7219.c | 19 +++++++++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/include/sound/da7219.h b/include/sound/da7219.h
index 1bfcb16f2d10ab..16ab125ad4adbf 100644
--- a/include/sound/da7219.h
+++ b/include/sound/da7219.h
@@ -38,6 +38,8 @@ struct da7219_pdata {
 
 	const char *dai_clks_name;
 
+	u32 vddio;
+
 	/* Mic */
 	enum da7219_micbias_voltage micbias_lvl;
 	enum da7219_mic_amp_in_sel mic_amp_in_sel;
diff --git a/sound/soc/codecs/da7219.c b/sound/soc/codecs/da7219.c
index 980a6a8bf56d38..d8f202c57f958d 100644
--- a/sound/soc/codecs/da7219.c
+++ b/sound/soc/codecs/da7219.c
@@ -1634,6 +1634,9 @@ static struct da7219_pdata *da7219_fw_to_pdata(struct snd_soc_component *compone
 	else
 		pdata->mic_amp_in_sel = DA7219_MIC_AMP_IN_SEL_DIFF;
 
+	if (!device_property_read_string(dev, "dlg,vddio", &of_val32))
+		pdata->vddio = of_val32;
+
 	return pdata;
 }
 
@@ -1717,8 +1720,12 @@ static int da7219_handle_supplies(struct snd_soc_component *component)
 	/* Determine VDDIO voltage provided */
 	vddio = da7219->supplies[DA7219_SUPPLY_VDDIO].consumer;
 	ret = regulator_get_voltage(vddio);
+	/* If regulator_get_voltage() fails, try to use vddio from pdata. */
+	if (ret < 0 && da7219->pdata)
+		ret = da7219->pdata->vddio;
 	if (ret < 1200000)
-		dev_warn(component->dev, "Invalid VDDIO voltage\n");
+		dev_warn(component->dev, "Invalid VDDIO voltage: %d mV\n",
+			 ret);
 	else if (ret < 2800000)
 		io_voltage_lvl = DA7219_IO_VOLTAGE_LEVEL_1_2V_2_8V;
 
@@ -1872,6 +1879,11 @@ static int da7219_probe(struct snd_soc_component *component)
 	mutex_init(&da7219->ctrl_lock);
 	mutex_init(&da7219->pll_lock);
 
+	/* Handle DT/ACPI/Platform data */
+	da7219->pdata = dev_get_platdata(component->dev);
+	if (!da7219->pdata)
+		da7219->pdata = da7219_fw_to_pdata(component);
+
 	/* Regulator configuration */
 	ret = da7219_handle_supplies(component);
 	if (ret)
@@ -1897,11 +1909,6 @@ static int da7219_probe(struct snd_soc_component *component)
 		break;
 	}
 
-	/* Handle DT/ACPI/Platform data */
-	da7219->pdata = dev_get_platdata(component->dev);
-	if (!da7219->pdata)
-		da7219->pdata = da7219_fw_to_pdata(component);
-
 	da7219_handle_pdata(component);
 
 	/* Check if MCLK provided */
-- 
2.18.0.233.g985f88cf7e-goog