[PATCH v4] ASoC: ssm2305: Add amplifier driver

[PATCH v4] ASoC: ssm2305: Add amplifier driver

[Marco Felsch]

The ssm2305 is a simple Class-D audio amplifier. A application can
turn on/off the device by a gpio. It's also possible to hardwire the
shutdown pin.

Tested on a i.MX6 based custom board.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
---

Notes (changelog):
    v2:
    - fix copyright information
    - rename shutdown gpio and add some more documentation
    - mark shutdown gpio as required
    - rm registration information
    
    v3:
    - fix error handling
    
    v4:
    - fix  license header

 .../devicetree/bindings/sound/adi,ssm2305.txt |  14 +++
 sound/soc/codecs/Kconfig                      |   7 ++
 sound/soc/codecs/Makefile                     |   2 +
 sound/soc/codecs/ssm2305.c                    | 104 ++++++++++++++++++
 4 files changed, 127 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sound/adi,ssm2305.txt
 create mode 100644 sound/soc/codecs/ssm2305.c

diff --git a/Documentation/devicetree/bindings/sound/adi,ssm2305.txt b/Documentation/devicetree/bindings/sound/adi,ssm2305.txt
new file mode 100644
index 000000000000..a9c9d83c8a30
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/adi,ssm2305.txt
@@ -0,0 +1,14 @@
+Analog Devices SSM2305 Speaker Amplifier
+========================================
+
+Required properties:
+  - compatible : "adi,ssm2305"
+  - shutdown-gpios : The gpio connected to the shutdown pin.
+                     The gpio signal is ACTIVE_LOW.
+
+Example:
+
+ssm2305: analog-amplifier {
+	compatible = "adi,ssm2305";
+	shutdown-gpios = <&gpio3 20 GPIO_ACTIVE_LOW>;
+};
diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index 9548f63ca531..d81b0cb291a3 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -142,6 +142,7 @@ config SND_SOC_ALL_CODECS
 	select SND_SOC_SI476X if MFD_SI476X_CORE
 	select SND_SOC_SIRF_AUDIO_CODEC
 	select SND_SOC_SPDIF
+	select SND_SOC_SSM2305
 	select SND_SOC_SSM2518 if I2C
 	select SND_SOC_SSM2602_SPI if SPI_MASTER
 	select SND_SOC_SSM2602_I2C if I2C
@@ -883,6 +884,12 @@ config SND_SOC_SIRF_AUDIO_CODEC
 config SND_SOC_SPDIF
 	tristate "S/PDIF CODEC"
 
+config SND_SOC_SSM2305
+	tristate "Analog Devices SSM2305 Class-D Amplifier"
+	help
+	  Enable support for Analog Devices SSM2305 filterless
+	  high-efficiency mono Class-D audio power amplifiers.
+
 config SND_SOC_SSM2518
 	tristate
 
diff --git a/sound/soc/codecs/Makefile b/sound/soc/codecs/Makefile
index e849d1495308..7d75ac8f6716 100644
--- a/sound/soc/codecs/Makefile
+++ b/sound/soc/codecs/Makefile
@@ -153,6 +153,7 @@ snd-soc-si476x-objs := si476x.o
 snd-soc-sirf-audio-codec-objs := sirf-audio-codec.o
 snd-soc-spdif-tx-objs := spdif_transmitter.o
 snd-soc-spdif-rx-objs := spdif_receiver.o
+snd-soc-ssm2305-objs := ssm2305.o
 snd-soc-ssm2518-objs := ssm2518.o
 snd-soc-ssm2602-objs := ssm2602.o
 snd-soc-ssm2602-spi-objs := ssm2602-spi.o
@@ -404,6 +405,7 @@ obj-$(CONFIG_SND_SOC_SIGMADSP_REGMAP)	+= snd-soc-sigmadsp-regmap.o
 obj-$(CONFIG_SND_SOC_SI476X)	+= snd-soc-si476x.o
 obj-$(CONFIG_SND_SOC_SPDIF)	+= snd-soc-spdif-rx.o snd-soc-spdif-tx.o
 obj-$(CONFIG_SND_SOC_SIRF_AUDIO_CODEC) += sirf-audio-codec.o
+obj-$(CONFIG_SND_SOC_SSM2305)	+= snd-soc-ssm2305.o
 obj-$(CONFIG_SND_SOC_SSM2518)	+= snd-soc-ssm2518.o
 obj-$(CONFIG_SND_SOC_SSM2602)	+= snd-soc-ssm2602.o
 obj-$(CONFIG_SND_SOC_SSM2602_SPI)	+= snd-soc-ssm2602-spi.o
diff --git a/sound/soc/codecs/ssm2305.c b/sound/soc/codecs/ssm2305.c
new file mode 100644
index 000000000000..d17864c3e2a9
--- /dev/null
+++ b/sound/soc/codecs/ssm2305.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Analog Devices SSM2305 Amplifier Driver
+//
+// Copyright (C) 2018 Pengutronix, Marco Felsch <kernel@pengutronix.de>
+//
+
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <sound/soc.h>
+
+#define DRV_NAME "ssm2305"
+
+struct ssm2305 {
+	/* shutdown gpio */
+	struct gpio_desc *gpiod_shutdown;
+};
+
+static int ssm2305_power_event(struct snd_soc_dapm_widget *w,
+			       struct snd_kcontrol *kctrl, int event)
+{
+	struct snd_soc_component *c = snd_soc_dapm_to_component(w->dapm);
+	struct ssm2305 *data = snd_soc_component_get_drvdata(c);
+
+	gpiod_set_value_cansleep(data->gpiod_shutdown,
+				 SND_SOC_DAPM_EVENT_ON(event));
+
+	return 0;
+}
+
+static const struct snd_soc_dapm_widget ssm2305_dapm_widgets[] = {
+	/* Stereo input/output */
+	SND_SOC_DAPM_INPUT("L_IN"),
+	SND_SOC_DAPM_INPUT("R_IN"),
+	SND_SOC_DAPM_OUTPUT("L_OUT"),
+	SND_SOC_DAPM_OUTPUT("R_OUT"),
+
+	SND_SOC_DAPM_SUPPLY("Power", SND_SOC_NOPM, 0, 0, ssm2305_power_event,
+			    SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMD),
+};
+
+static const struct snd_soc_dapm_route ssm2305_dapm_routes[] = {
+	{ "L_OUT", NULL, "L_IN" },
+	{ "R_OUT", NULL, "R_IN" },
+	{ "L_IN", NULL, "Power" },
+	{ "R_IN", NULL, "Power" },
+};
+
+static const struct snd_soc_component_driver ssm2305_component_driver = {
+	.dapm_widgets		= ssm2305_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(ssm2305_dapm_widgets),
+	.dapm_routes		= ssm2305_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(ssm2305_dapm_routes),
+};
+
+static int ssm2305_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ssm2305 *priv;
+	int err;
+
+	/* Allocate the private data */
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	/* Get shutdown gpio */
+	priv->gpiod_shutdown = devm_gpiod_get(dev, "shutdown",
+					      GPIOD_OUT_LOW);
+	if (IS_ERR(priv->gpiod_shutdown)) {
+		err = PTR_ERR(priv->gpiod_shutdown);
+		if (err != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get 'shutdown' gpio: %d\n",
+				err);
+		return err;
+	}
+
+	return devm_snd_soc_register_component(dev, &ssm2305_component_driver,
+					       NULL, 0);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id ssm2305_of_match[] = {
+	{ .compatible = "adi,ssm2305", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ssm2305_of_match);
+#endif
+
+static struct platform_driver ssm2305_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = of_match_ptr(ssm2305_of_match),
+	},
+	.probe = ssm2305_probe,
+};
+
+module_platform_driver(ssm2305_driver);
+
+MODULE_DESCRIPTION("ASoC SSM2305 amplifier driver");
+MODULE_AUTHOR("Marco Felsch <m.felsch@pengutronix.de>");
+MODULE_LICENSE("GPL v2");
-- 
2.17.0

Re: [PATCH v4] ASoC: ssm2305: Add amplifier driver

[Mark Brown]

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On Fri, May 18, 2018 at 10:52:42AM +0200, Marco Felsch wrote:
> The ssm2305 is a simple Class-D audio amplifier. A application can
> turn on/off the device by a gpio. It's also possible to hardwire the
> shutdown pin.

Please don't resubmit patches that have already been applied, you should
submit patches against current code in the tree you're expecting things
to be applied to.  If any updates are needed to a patch that's already
been applied you should submit incremental patches which make those
updates.  This avoids having to change published git commits which could
cause problems for people working against git.

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