ASoC: max9759: Add Amplifier Driver

The max9759 is a gpio controlled amplifier.
Tested on a Variscite Dart MX6 SoM based custom board.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/Kconfig

@@ -98,6 +98,7 @@ config SND_SOC_ALL_CODECS
 	select SND_SOC_MAX98373 if I2C
 	select SND_SOC_MAX9850 if I2C
 	select SND_SOC_MAX9860 if I2C
+	select SND_SOC_MAX9759
 	select SND_SOC_MAX9768 if I2C
 	select SND_SOC_MAX9877 if I2C
 	select SND_SOC_MC13783 if MFD_MC13XXX
@@ -1187,6 +1188,10 @@ config SND_SOC_ZX_AUD96P22
 config SND_SOC_LM4857
 	tristate
 
+config SND_SOC_MAX9759
+	tristate "Maxim MAX9759 speaker Amplifier"
+	select GPIOLIB
+
 config SND_SOC_MAX9768
 	tristate
 

sound/soc/codecs/Makefile

@@ -80,6 +80,7 @@ snd-soc-jz4740-codec-objs := jz4740.o
 snd-soc-l3-objs := l3.o
 snd-soc-lm4857-objs := lm4857.o
 snd-soc-lm49453-objs := lm49453.o
+snd-soc-max9759-objs := max9759.o
 snd-soc-max9768-objs := max9768.o
 snd-soc-max98088-objs := max98088.o
 snd-soc-max98090-objs := max98090.o
@@ -325,6 +326,7 @@ obj-$(CONFIG_SND_SOC_JZ4740_CODEC)	+= snd-soc-jz4740-codec.o
 obj-$(CONFIG_SND_SOC_L3)	+= snd-soc-l3.o
 obj-$(CONFIG_SND_SOC_LM4857)	+= snd-soc-lm4857.o
 obj-$(CONFIG_SND_SOC_LM49453)   += snd-soc-lm49453.o
+obj-$(CONFIG_SND_SOC_MAX9759)	+= snd-soc-max9759.o
 obj-$(CONFIG_SND_SOC_MAX9768)	+= snd-soc-max9768.o
 obj-$(CONFIG_SND_SOC_MAX98088)	+= snd-soc-max98088.o
 obj-$(CONFIG_SND_SOC_MAX98090)	+= snd-soc-max98090.o

sound/soc/codecs/max9759.c

@@ -0,0 +1,207 @@
+// SPDX-Licence-Identifier: GPL-2.0
+/*
+ * MAX9759 Amplifier Driver
+ *
+ * Copyright (c) 2017 BayLibre, SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <sound/soc.h>
+#include <sound/soc-dapm.h>
+#include <sound/tlv.h>
+
+#define DRV_NAME "max9759"
+
+struct max9759 {
+	struct gpio_desc *gpiod_shutdown;
+	struct gpio_desc *gpiod_mute;
+	struct gpio_descs *gpiod_gain;
+	bool is_mute;
+	unsigned int gain;
+};
+
+static int pga_event(struct snd_soc_dapm_widget *w,
+		     struct snd_kcontrol *control, int event)
+{
+	struct snd_soc_component *c = snd_soc_dapm_to_component(w->dapm);
+	struct max9759 *priv = snd_soc_component_get_drvdata(c);
+
+	if (SND_SOC_DAPM_EVENT_ON(event))
+		gpiod_set_value_cansleep(priv->gpiod_shutdown, 0);
+	else
+		gpiod_set_value_cansleep(priv->gpiod_shutdown, 1);
+
+	return 0;
+}
+
+/* From 6dB to 24dB in steps of 6dB */
+static const DECLARE_TLV_DB_SCALE(speaker_gain_tlv, 600, 600, 0);
+
+static int speaker_gain_control_get(struct snd_kcontrol *kcontrol,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *c = snd_soc_kcontrol_component(kcontrol);
+	struct max9759 *priv = snd_soc_component_get_drvdata(c);
+
+	ucontrol->value.integer.value[0] = priv->gain;
+
+	return 0;
+}
+
+static const bool speaker_gain_table[4][2] = {
+	/* G1, G2 */
+	{true, true},	/* +6dB */
+	{false, true},	/* +12dB */
+	{true, false},	/* +18dB */
+	{false, false},	/* +24dB */
+};
+
+static int speaker_gain_control_put(struct snd_kcontrol *kcontrol,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *c = snd_soc_kcontrol_component(kcontrol);
+	struct max9759 *priv = snd_soc_component_get_drvdata(c);
+
+	if (ucontrol->value.integer.value[0] > 3)
+		return -EINVAL;
+
+	priv->gain = ucontrol->value.integer.value[0];
+
+	/* G1 */
+	gpiod_set_value_cansleep(priv->gpiod_gain->desc[0],
+				 speaker_gain_table[priv->gain][0]);
+	/* G2 */
+	gpiod_set_value_cansleep(priv->gpiod_gain->desc[1],
+				 speaker_gain_table[priv->gain][1]);
+
+	return 1;
+}
+
+static int speaker_mute_get(struct snd_kcontrol *kcontrol,
+			    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *c = snd_soc_kcontrol_component(kcontrol);
+	struct max9759 *priv = snd_soc_component_get_drvdata(c);
+
+	ucontrol->value.integer.value[0] = !priv->is_mute;
+
+	return 0;
+}
+
+static int speaker_mute_put(struct snd_kcontrol *kcontrol,
+			    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *c = snd_soc_kcontrol_component(kcontrol);
+	struct max9759 *priv = snd_soc_component_get_drvdata(c);
+
+	priv->is_mute = !ucontrol->value.integer.value[0];
+
+	gpiod_set_value_cansleep(priv->gpiod_mute, priv->is_mute);
+
+	return 1;
+}
+
+static const struct snd_kcontrol_new max9759_dapm_controls[] = {
+	SOC_SINGLE_EXT_TLV("Speaker Gain Volume", 0, 0, 3, 0,
+			   speaker_gain_control_get, speaker_gain_control_put,
+			   speaker_gain_tlv),
+	SOC_SINGLE_BOOL_EXT("Playback Switch", 0,
+			    speaker_mute_get, speaker_mute_put),
+};
+
+static const struct snd_soc_dapm_widget max9759_dapm_widgets[] = {
+	SND_SOC_DAPM_INPUT("INL"),
+	SND_SOC_DAPM_INPUT("INR"),
+	SND_SOC_DAPM_PGA_E("PGA", SND_SOC_NOPM, 0, 0, NULL, 0, pga_event,
+			   (SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMD)),
+	SND_SOC_DAPM_OUTPUT("OUTL"),
+	SND_SOC_DAPM_OUTPUT("OUTR"),
+};
+
+static const struct snd_soc_dapm_route max9759_dapm_routes[] = {
+	{ "PGA", NULL, "INL" },
+	{ "PGA", NULL, "INR" },
+	{ "OUTL", NULL, "PGA" },
+	{ "OUTR", NULL, "PGA" },
+};
+
+static const struct snd_soc_component_driver max9759_component_driver = {
+	.controls		= max9759_dapm_controls,
+	.num_controls		= ARRAY_SIZE(max9759_dapm_controls),
+	.dapm_widgets		= max9759_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(max9759_dapm_widgets),
+	.dapm_routes		= max9759_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(max9759_dapm_routes),
+};
+
+static int max9759_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct max9759 *priv;
+	int err;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	priv->gpiod_shutdown = devm_gpiod_get(dev, "shutdown", GPIOD_OUT_HIGH);
+	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", err);
+		return err;
+	}
+
+	priv->gpiod_mute = devm_gpiod_get(dev, "mute", GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->gpiod_mute)) {
+		err = PTR_ERR(priv->gpiod_mute);
+		if (err != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get 'mute' gpio: %d", err);
+		return err;
+	}
+	priv->is_mute = true;
+
+	priv->gpiod_gain = devm_gpiod_get_array(dev, "gain", GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->gpiod_gain)) {
+		err = PTR_ERR(priv->gpiod_gain);
+		if (err != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get 'gain' gpios: %d", err);
+		return err;
+	}
+	priv->gain = 0;
+
+	if (priv->gpiod_gain->ndescs != 2) {
+		dev_err(dev, "Invalid 'gain' gpios count: %d",
+			priv->gpiod_gain->ndescs);
+		return -EINVAL;
+	}
+
+	return devm_snd_soc_register_component(dev, &max9759_component_driver,
+					       NULL, 0);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id max9759_ids[] = {
+	{ .compatible = "maxim,max9759", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max9759_ids);
+#endif
+
+static struct platform_driver max9759_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = of_match_ptr(max9759_ids),
+	},
+	.probe = max9759_probe,
+};
+
+module_platform_driver(max9759_driver);
+
+MODULE_DESCRIPTION("ASoC MAX9759 amplifier driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_LICENSE("GPL");