[PATCH v2 09/17] ASoC: simple-amplifier: Introduce support for gpio-audio-amp

Herve Codina
2026-04-29T07:44:35Z

Improve the simple-amplifier introducing preliminary support for
gpio-audio-amp.

Those amplifiers are amplifiers driven by gpios.

This support introduction doesn't handle any GPIO yet but introduces
the compatible strings and the related DAPM table.

Two gpio-audio-amp are available: A mono and a stereo version.

The mono version has only one audio channel and gpio settings impact
features such as the gain or mute of this sole channel.

The stereo version has two channels (left and right). Gpio settings
impact both channels in the same manner and at the same time. For
instance, the gain setting set the gain of both channels as well as
the mute setting mutes both channels.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
sound/soc/codecs/simple-amplifier.c | 54 +++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)

diff --git a/sound/soc/codecs/simple-amplifier.c b/sound/soc/codecs/simple-amplifier.c
index a70f70566340..ab4fa074603e 100644
--- a/sound/soc/codecs/simple-amplifier.c
+++ b/sound/soc/codecs/simple-amplifier.c
@@ -4,6 +4,7 @@
* Author: Jerome Brunet <jbrunet@baylibre.com>
*/

+#include <linux/bits.h>
#include <linux/gpio/consumer.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
@@ -12,6 +13,9 @@
#include <sound/soc.h>

struct simple_amp_data {
+ unsigned int supports;
+#define SIMPLE_AUDIO_SUPPORT_PGA BIT(0)
+
const struct snd_soc_dapm_widget *dapm_widgets;
unsigned int num_dapm_widgets;
const struct snd_soc_dapm_route *dapm_routes;
@@ -66,6 +70,38 @@ static const struct snd_soc_dapm_route simple_amp_dapm_routes[] = {
{ "OUTR", NULL, "DRV" },
};

+static const struct snd_soc_dapm_widget simple_amp_mono_pga_dapm_widgets[] = {
+ SND_SOC_DAPM_INPUT("IN"),
+ SND_SOC_DAPM_OUTPUT("OUT"),
+ SND_SOC_DAPM_PGA_E("PGA", SND_SOC_NOPM, 0, 0, NULL, 0, simple_amp_power_event,
+ (SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD)),
+ SND_SOC_DAPM_REGULATOR_SUPPLY("vdd", 0, 0),
+};
+
+static const struct snd_soc_dapm_route simple_amp_mono_pga_dapm_routes[] = {
+ { "PGA", NULL, "IN" },
+ { "PGA", NULL, "vdd" },
+ { "OUT", NULL, "PGA" },
+};
+
+static const struct snd_soc_dapm_widget simple_amp_stereo_pga_dapm_widgets[] = {
+ SND_SOC_DAPM_INPUT("INL"),
+ SND_SOC_DAPM_INPUT("INR"),
+ SND_SOC_DAPM_OUTPUT("OUTL"),
+ SND_SOC_DAPM_OUTPUT("OUTR"),
+ SND_SOC_DAPM_PGA_E("PGA", SND_SOC_NOPM, 0, 0, NULL, 0, simple_amp_power_event,
+ (SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD)),
+ SND_SOC_DAPM_REGULATOR_SUPPLY("vdd", 0, 0),
+};
+
+static const struct snd_soc_dapm_route simple_amp_stereo_pga_dapm_routes[] = {
+ { "PGA", NULL, "INL" },
+ { "PGA", NULL, "INR" },
+ { "PGA", NULL, "vdd" },
+ { "OUTL", NULL, "PGA" },
+ { "OUTR", NULL, "PGA" },
+};
+
static int simple_amp_add_basic_dapm(struct snd_soc_component *component)
{
struct snd_soc_dapm_context *dapm = snd_soc_component_to_dapm(component);
@@ -133,9 +169,27 @@ static const struct simple_amp_data simple_audio_amplifier_data = {
.num_dapm_routes = ARRAY_SIZE(simple_amp_dapm_routes),
};

+static const struct simple_amp_data simple_audio_mono_pga_data = {
+ .supports = SIMPLE_AUDIO_SUPPORT_PGA,
+ .dapm_widgets = simple_amp_mono_pga_dapm_widgets,
+ .num_dapm_widgets = ARRAY_SIZE(simple_amp_mono_pga_dapm_widgets),
+ .dapm_routes = simple_amp_mono_pga_dapm_routes,
+ .num_dapm_routes = ARRAY_SIZE(simple_amp_mono_pga_dapm_routes),
+};
+
+static const struct simple_amp_data simple_audio_stereo_pga_data = {
+ .supports = SIMPLE_AUDIO_SUPPORT_PGA,
+ .dapm_widgets = simple_amp_stereo_pga_dapm_widgets,
+ .num_dapm_widgets = ARRAY_SIZE(simple_amp_stereo_pga_dapm_widgets),
+ .dapm_routes = simple_amp_stereo_pga_dapm_routes,
+ .num_dapm_routes = ARRAY_SIZE(simple_amp_stereo_pga_dapm_routes),
+};
+
static const struct of_device_id simple_amp_ids[] = {
{ .compatible = "dioo,dio2125", .data = &simple_audio_amplifier_data},
{ .compatible = "simple-audio-amplifier", .data = &simple_audio_amplifier_data},
+ { .compatible = "gpio-audio-amp-mono", .data = &simple_audio_mono_pga_data},
+ { .compatible = "gpio-audio-amp-stereo", .data = &simple_audio_stereo_pga_data},
{ }
};
MODULE_DEVICE_TABLE(of, simple_amp_ids);
--
2.53.0