[PATCH v2 4/7] ASoC: samsung: midas_wm1811: Add GPIO-based headset jack detection
Artur Weber
aweber.kernel at gmail.com
Wed May 8 03:58:52 PDT 2024
Some Samsung devices that use the midas_wm1811 driver use a GPIO-based
method for detecting whether the headset jack is plugged in, as well as
detecting which headset buttons are pressed. There are two GPIOs:
a "headset detect" GPIO responsible for detecting jack insertion, and
a "headset key" GPIO which triggers when a button on the headset is
pressed. The plug type and the button pressed are determined based
on information from an ADC channel. The headset mic is enabled by a
headset mic bias regulator.
Add support for the GPIO-based headset jack detection mechanism,
and make it configurable from the device tree.
This implementation borrows somewhat from the aries_wm8994.c driver,
though there are a few changes to make the code cleaner, and to add
support for DT-based configuration.
Notably, a dependency on IIO is introduced, to accommodate the ADC
reading requirement.
Signed-off-by: Artur Weber <aweber.kernel at gmail.com>
---
Changes in v2:
- Added separate headset mic bias regulator
- Added samsung preset to threshold properties
- Replaced dev_err+return with return dev_err_probe where needed
---
sound/soc/samsung/Kconfig | 2 +-
sound/soc/samsung/midas_wm1811.c | 286 +++++++++++++++++++++++++++++++++++++--
2 files changed, 277 insertions(+), 11 deletions(-)
diff --git a/sound/soc/samsung/Kconfig b/sound/soc/samsung/Kconfig
index 93c2b1b08d0a..4b1ea7b2c796 100644
--- a/sound/soc/samsung/Kconfig
+++ b/sound/soc/samsung/Kconfig
@@ -140,7 +140,7 @@ config SND_SOC_SAMSUNG_ARIES_WM8994
config SND_SOC_SAMSUNG_MIDAS_WM1811
tristate "SoC I2S Audio support for Midas boards"
- depends on SND_SOC_SAMSUNG
+ depends on SND_SOC_SAMSUNG && IIO
select SND_SAMSUNG_I2S
select SND_SOC_WM8994
help
diff --git a/sound/soc/samsung/midas_wm1811.c b/sound/soc/samsung/midas_wm1811.c
index ab0a4804b45e..ce94550ee32e 100644
--- a/sound/soc/samsung/midas_wm1811.c
+++ b/sound/soc/samsung/midas_wm1811.c
@@ -7,7 +7,9 @@
#include <linux/clk.h>
#include <linux/gpio/consumer.h>
+#include <linux/iio/consumer.h>
#include <linux/mfd/wm8994/registers.h>
+#include <linux/input-event-codes.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>
@@ -32,6 +34,9 @@ struct midas_priv {
struct regulator *reg_headset_mic_bias;
struct gpio_desc *gpio_fm_sel;
struct gpio_desc *gpio_lineout_sel;
+ struct gpio_desc *gpio_headset_detect;
+ struct gpio_desc *gpio_headset_key;
+ struct iio_channel *adc_headset_detect;
unsigned int fll1_rate;
struct snd_soc_jack headset_jack;
@@ -48,6 +53,131 @@ static struct snd_soc_jack_pin headset_jack_pins[] = {
},
};
+/*
+ * min_mv/max_mv values in this struct are set up based on DT values.
+ */
+static struct snd_soc_jack_zone headset_jack_zones[] = {
+ { .jack_type = SND_JACK_HEADPHONE, },
+ { .jack_type = SND_JACK_HEADSET, },
+ { .jack_type = SND_JACK_HEADPHONE, },
+};
+
+/*
+ * This is used for manual detection in headset_key_check, we reuse the
+ * structure since it's convenient.
+ *
+ * min_mv/max_mv values in this struct are set up based on DT values.
+ */
+static struct snd_soc_jack_zone headset_key_zones[] = {
+ { .jack_type = SND_JACK_BTN_0, }, /* Media */
+ { .jack_type = SND_JACK_BTN_1, }, /* Volume Up */
+ { .jack_type = SND_JACK_BTN_2, }, /* Volume Down */
+};
+
+static int headset_jack_check(void *data)
+{
+ struct midas_priv *priv = (struct midas_priv *) data;
+ int adc, jack_type, ret;
+ int bias_already_on = 0;
+
+ if (!gpiod_get_value_cansleep(priv->gpio_headset_detect))
+ return 0;
+
+ if (priv->reg_headset_mic_bias) {
+ /*
+ * Get state of Headset Mic switch by checking the headset mic
+ * bias regulator
+ */
+ bias_already_on = \
+ regulator_is_enabled(priv->reg_headset_mic_bias);
+
+ /*
+ * If it's not enabled yet, temporarily enable headset mic bias
+ * for ADC measurement
+ */
+ if (bias_already_on < 0)
+ pr_err("%s: Failed to get headset mic bias state: %d",
+ __func__, ret);
+ else if (!bias_already_on) {
+ ret = regulator_enable(priv->reg_headset_mic_bias);
+ if (ret)
+ pr_err("%s: Failed to enable micbias: %d\n",
+ __func__, ret);
+ }
+ }
+
+ /* Sleep for a small amount of time to get the value to stabilize */
+ msleep(20);
+
+ ret = iio_read_channel_processed(priv->adc_headset_detect, &adc);
+ if (ret) {
+ pr_err("%s: Failed to read ADC (%d), assuming headphones\n",
+ __func__, ret);
+ return SND_JACK_HEADPHONE;
+ }
+ pr_debug("%s: ADC value is %d\n", __func__, adc);
+
+ jack_type = snd_soc_jack_get_type(&priv->headset_jack, adc);
+
+ /*
+ * Revert the headset mic bias supply to its previous state
+ * (i.e. if it was disabled before the check, disable it again)
+ */
+ if (priv->reg_headset_mic_bias && bias_already_on == 0) {
+ ret = regulator_disable(priv->reg_headset_mic_bias);
+ if (ret)
+ pr_err("%s: Failed to disable micbias: %d\n",
+ __func__, ret);
+ }
+
+ return jack_type;
+}
+
+static int headset_key_check(void *data)
+{
+ struct midas_priv *priv = (struct midas_priv *) data;
+ int adc, i, ret;
+
+ if (!gpiod_get_value_cansleep(priv->gpio_headset_key))
+ return 0;
+
+ /* Filter out keypresses when 4 pole jack not detected */
+ if (!(priv->headset_jack.status & SND_JACK_MICROPHONE))
+ return 0;
+
+ ret = iio_read_channel_processed(priv->adc_headset_detect, &adc);
+ if (ret) {
+ pr_err("%s: Failed to read ADC (%d), can't detect key type\n",
+ __func__, ret);
+ return 0;
+ }
+ pr_debug("%s: ADC value is %d\n", __func__, adc);
+
+ for (i = 0; i < ARRAY_SIZE(headset_key_zones); i++) {
+ if (adc >= headset_key_zones[i].min_mv &&
+ adc <= headset_key_zones[i].max_mv) {
+ return headset_key_zones[i].jack_type;
+ }
+ }
+
+ return 0;
+}
+
+static struct snd_soc_jack_gpio headset_gpio[] = {
+ {
+ .name = "Headset Jack",
+ .report = SND_JACK_HEADSET,
+ .debounce_time = 150,
+ .jack_status_check = headset_jack_check,
+ },
+ {
+ .name = "Headset Key",
+ .report = SND_JACK_BTN_0 | SND_JACK_BTN_1 | SND_JACK_BTN_2,
+ .debounce_time = 30,
+ .jack_status_check = headset_key_check,
+ },
+};
+
static int midas_start_fll1(struct snd_soc_pcm_runtime *rtd, unsigned int rate)
{
struct snd_soc_card *card = rtd->card;
@@ -335,18 +465,67 @@ static int midas_late_probe(struct snd_soc_card *card)
return ret;
}
- ret = snd_soc_card_jack_new_pins(card, "Headset",
- SND_JACK_HEADSET | SND_JACK_MECHANICAL |
- SND_JACK_BTN_0 | SND_JACK_BTN_1 | SND_JACK_BTN_2 |
- SND_JACK_BTN_3 | SND_JACK_BTN_4 | SND_JACK_BTN_5,
- &priv->headset_jack,
- headset_jack_pins,
- ARRAY_SIZE(headset_jack_pins));
- if (ret)
+ if (!priv->gpio_headset_detect) {
+ ret = snd_soc_card_jack_new_pins(card, "Headset",
+ SND_JACK_HEADSET | SND_JACK_MECHANICAL |
+ SND_JACK_BTN_0 | SND_JACK_BTN_1 |
+ SND_JACK_BTN_2 | SND_JACK_BTN_3 |
+ SND_JACK_BTN_4 | SND_JACK_BTN_5,
+ &priv->headset_jack,
+ headset_jack_pins,
+ ARRAY_SIZE(headset_jack_pins));
+ if (ret)
+ return ret;
+
+ wm8958_mic_detect(aif1_dai->component, &priv->headset_jack,
+ NULL, NULL, NULL, NULL);
+ } else {
+ /* Some devices (n8000, t310) use a GPIO to detect the jack. */
+ ret = snd_soc_card_jack_new_pins(card, "Headset",
+ SND_JACK_HEADSET | SND_JACK_BTN_0 |
+ SND_JACK_BTN_1 | SND_JACK_BTN_2,
+ &priv->headset_jack,
+ headset_jack_pins,
+ ARRAY_SIZE(headset_jack_pins));
+ if (ret) {
+ dev_err(card->dev,
+ "Failed to set up headset pins: %d\n", ret);
+ return ret;
+ }
+
+ ret = snd_soc_jack_add_zones(&priv->headset_jack,
+ ARRAY_SIZE(headset_jack_zones),
+ headset_jack_zones);
+ if (ret) {
+ dev_err(card->dev,
+ "Failed to set up headset zones: %d\n", ret);
+ return ret;
+ }
+
+ headset_gpio[0].data = priv;
+ headset_gpio[0].desc = priv->gpio_headset_detect;
+
+ headset_gpio[1].data = priv;
+ headset_gpio[1].desc = priv->gpio_headset_key;
+
+ snd_jack_set_key(priv->headset_jack.jack,
+ SND_JACK_BTN_0, KEY_MEDIA);
+ snd_jack_set_key(priv->headset_jack.jack,
+ SND_JACK_BTN_1, KEY_VOLUMEUP);
+ snd_jack_set_key(priv->headset_jack.jack,
+ SND_JACK_BTN_2, KEY_VOLUMEDOWN);
+
+ ret = snd_soc_jack_add_gpios(&priv->headset_jack,
+ ARRAY_SIZE(headset_gpio),
+ headset_gpio);
+ if (ret)
+ dev_err(card->dev,
+ "Failed to set up headset jack GPIOs: %d\n",
+ ret);
+
return ret;
+ }
- wm8958_mic_detect(aif1_dai->component, &priv->headset_jack,
- NULL, NULL, NULL, NULL);
return 0;
}
@@ -453,6 +632,9 @@ static int midas_probe(struct platform_device *pdev)
struct snd_soc_card *card = &midas_card;
struct device *dev = &pdev->dev;
static struct snd_soc_dai_link *dai_link;
+ enum iio_chan_type channel_type;
+ u32 fourpole_threshold[2];
+ u32 button_threshold[3];
struct midas_priv *priv;
int ret, i;
@@ -499,6 +681,90 @@ static int midas_probe(struct platform_device *pdev)
return PTR_ERR(priv->gpio_lineout_sel);
}
+ priv->gpio_headset_detect = devm_gpiod_get_optional(dev,
+ "headset-detect", GPIOD_IN);
+ if (IS_ERR(priv->gpio_headset_detect))
+ return dev_err_probe(dev, PTR_ERR(priv->gpio_headset_detect),
+ "Failed to get headset jack detect GPIO\n");
+
+ if (priv->gpio_headset_detect) {
+ priv->adc_headset_detect = devm_iio_channel_get(dev,
+ "headset-detect");
+ if (IS_ERR(priv->adc_headset_detect))
+ return dev_err_probe(dev,
+ PTR_ERR(priv->adc_headset_detect),
+ "Failed to get ADC channel\n");
+
+ ret = iio_get_channel_type(priv->adc_headset_detect,
+ &channel_type);
+ if (ret) {
+ dev_err(dev, "Failed to get ADC channel type\n");
+ return ret;
+ }
+
+ if (channel_type != IIO_VOLTAGE) {
+ dev_err(dev, "ADC channel is not voltage\n");
+ return ret;
+ }
+
+ priv->gpio_headset_key = devm_gpiod_get(dev, "headset-key",
+ GPIOD_IN);
+ if (IS_ERR(priv->gpio_headset_key))
+ return dev_err_probe(dev,
+ PTR_ERR(priv->gpio_headset_key),
+ "Failed to get headset key GPIO\n");
+
+ ret = of_property_read_u32_array(dev->of_node,
+ "samsung,headset-4pole-threshold-microvolt",
+ fourpole_threshold,
+ ARRAY_SIZE(fourpole_threshold));
+ if (ret) {
+ dev_err(dev, "Failed to get 4-pole jack detection threshold\n");
+ return ret;
+ }
+
+ if (fourpole_threshold[0] > fourpole_threshold[1]) {
+ dev_err(dev, "Invalid 4-pole jack detection threshold value\n");
+ return -EINVAL;
+ }
+
+ headset_jack_zones[0].max_mv = (fourpole_threshold[0]);
+ headset_jack_zones[1].min_mv = (fourpole_threshold[0] + 1);
+
+ headset_jack_zones[1].max_mv = (fourpole_threshold[1]);
+ headset_jack_zones[2].min_mv = (fourpole_threshold[1] + 1);
+
+ ret = of_property_read_u32_array(dev->of_node,
+ "samsung,headset-button-threshold-microvolt",
+ button_threshold,
+ ARRAY_SIZE(button_threshold));
+ if (ret) {
+ dev_err(dev, "Failed to get headset button detection threshold\n");
+ return ret;
+ }
+
+ if (button_threshold[0] > button_threshold[1] ||
+ button_threshold[1] > button_threshold[2]) {
+ dev_err(dev, "Invalid headset button detection threshold value\n");
+ return -EINVAL;
+ }
+
+ for (i = 0; i < 3; i++) {
+ if (i != 0 && button_threshold[i] <= 0) {
+ dev_err(dev, "Invalid headset button detection threshold value\n");
+ return -EINVAL;
+ }
+
+ headset_key_zones[i].min_mv = button_threshold[i];
+
+ if (i == 2)
+ headset_key_zones[i].max_mv = UINT_MAX;
+ else
+ headset_key_zones[i].max_mv = \
+ (button_threshold[i+1] - 1);
+ }
+ }
+
ret = snd_soc_of_parse_card_name(card, "model");
if (ret < 0) {
dev_err(dev, "Card name is not specified\n");
--
2.45.0
More information about the linux-arm-kernel
mailing list