[PATCH v6 2/2] ASoC: rt715:add micmute led state control supports

[Perry Yuan]

From: Perry Yuan <perry_yuan@xxxxxxxx>

Some new Dell system is going to support audio internal micphone
privacy setting from hardware level with micmute led state changing
When micmute hotkey pressed by user, soft mute will need to be enabled
firstly in case of pop noise, and codec driver need to react to mic
mute event to EC(embedded controller) notifying that SW mute is completed
Then EC will do the hardware mute physically within the timeout reached

This patch allow codec rt715 and rt715 sdca driver to change the local micmute
led state. Dell privacy led trigger driver will ack EC when micmute key pressed
through this micphone led control interface like hda_generic provided
ACPI method defined in dell-privacy micmute led trigger will be called
for notifying the EC that software mute has been completed, then hardware
audio circuit solution controlled by EC will switch the audio input source off/on

Signed-off-by: Perry Yuan <perry_yuan@xxxxxxxx>

--------
v5 -> v6:
* addresed review comments from Jaroslav
* add quirks for micmute led control as short term solution to control
  micmute led state change
v4 -> v5:
* rebase to latest 5.12 rc4 upstream kernel
v3 -> v4:
* remove unused debug log
* remove compile flag of DELL privacy
* move the micmute_led to local from rt715_priv
* when Jaroslav upstream his gerneric LED trigger driver,I will rebase
  this patch,please consider merge this at first
  https://lore.kernel.org/alsa-devel/20210211111400.1131020-1-perex@xxxxxxxx/
v2 -> v3:
* simplify the patch to reuse some val value
* add more detail to the commit info
v1 -> v2:
* fix some format issue
--------
---
 sound/soc/codecs/rt715-sdca.c | 41 ++++++++++++++++++++++++++++++++++-
 sound/soc/codecs/rt715.c      | 41 +++++++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/rt715-sdca.c b/sound/soc/codecs/rt715-sdca.c
index 20528afbdc57..7bd7ad0ba7d7 100644
--- a/sound/soc/codecs/rt715-sdca.c
+++ b/sound/soc/codecs/rt715-sdca.c
@@ -11,12 +11,14 @@
 #include <linux/moduleparam.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/leds.h>
 #include <linux/pm_runtime.h>
 #include <linux/pm.h>
 #include <linux/soundwire/sdw.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
+#include <linux/dmi.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
@@ -344,6 +346,34 @@ static int rt715_sdca_get_volsw(struct snd_kcontrol *kcontrol,
 	return 0;
 }
 
+static bool micmute_led_set;
+static int  dmi_matched(const struct dmi_system_id *dmi)
+{
+	micmute_led_set = 1;
+	return 1;
+}
+
+/* Some systems will need to use this to trigger mic mute LED state changed */
+static const struct dmi_system_id micmute_led_dmi_table[] = {
+	{
+		.callback = dmi_matched,
+		.ident = "Dell Latitude 9420",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude 9420"),
+		},
+	},
+	{
+		.callback = dmi_matched,
+		.ident = "Dell Latitude 9520",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude 9520"),
+		},
+	},
+	{},
+};
+
 static int rt715_sdca_put_volsw(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol)
 {
@@ -358,6 +388,7 @@ static int rt715_sdca_put_volsw(struct snd_kcontrol *kcontrol,
 	unsigned int mask = (1 << fls(max)) - 1;
 	unsigned int invert = p->invert;
 	int err;
+	bool micmute_led;
 
 	for (i = 0; i < 4; i++) {
 		if (ucontrol->value.integer.value[i] != rt715->kctl_switch_orig[i]) {
@@ -393,7 +424,15 @@ static int rt715_sdca_put_volsw(struct snd_kcontrol *kcontrol,
 		if (err < 0)
 			return err;
 	}
-
+	/* Micmute LED state changed by muted/unmute switch */
+	dmi_check_system(micmute_led_dmi_table);
+	if (invert && micmute_led_set) {
+		if (ucontrol->value.integer.value[0] || ucontrol->value.integer.value[1])
+			micmute_led = LED_OFF;
+		else
+			micmute_led = LED_ON;
+		ledtrig_audio_set(LED_AUDIO_MICMUTE, micmute_led);
+	}
 	return k_changed;
 }
 
diff --git a/sound/soc/codecs/rt715.c b/sound/soc/codecs/rt715.c
index 34c3357e943b..490cf9e63c2d 100644
--- a/sound/soc/codecs/rt715.c
+++ b/sound/soc/codecs/rt715.c
@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
+#include <linux/leds.h>
 #include <linux/pm_runtime.h>
 #include <linux/pm.h>
 #include <linux/soundwire/sdw.h>
@@ -25,6 +26,7 @@
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/of_device.h>
+#include <linux/dmi.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
@@ -70,6 +72,34 @@ static void rt715_get_gain(struct rt715_priv *rt715, unsigned int addr_h,
 		pr_err("Failed to get L channel gain.\n");
 }
 
+static bool micmute_led_set;
+static int  dmi_matched(const struct dmi_system_id *dmi)
+{
+	micmute_led_set = 1;
+	return 1;
+}
+
+/* Some systems will need to use this to trigger mic mute LED state changed */
+static const struct dmi_system_id micmute_led_dmi_table[] = {
+	{
+		.callback = dmi_matched,
+		.ident = "Dell Latitude 9420",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude 9420"),
+		},
+	},
+	{
+		.callback = dmi_matched,
+		.ident = "Dell Latitude 9520",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude 9520"),
+		},
+	},
+	{},
+};
+
 /* For Verb-Set Amplifier Gain (Verb ID = 3h) */
 static int rt715_set_amp_gain_put(struct snd_kcontrol *kcontrol,
 					struct snd_ctl_elem_value *ucontrol)
@@ -88,6 +118,7 @@ static int rt715_set_amp_gain_put(struct snd_kcontrol *kcontrol,
 		RT715_SET_GAIN_MIX_ADC2_L};
 	unsigned int addr_h, addr_l, val_h, val_ll, val_lr;
 	unsigned int read_ll, read_rl, i, j, loop_cnt;
+	bool micmute_led;
 
 	if (strstr(ucontrol->id.name, "Main Capture Switch") ||
 		strstr(ucontrol->id.name, "Main Capture Volume"))
@@ -185,6 +216,16 @@ static int rt715_set_amp_gain_put(struct snd_kcontrol *kcontrol,
 	if (dapm->bias_level <= SND_SOC_BIAS_STANDBY)
 		regmap_write(rt715->regmap,
 				RT715_SET_AUDIO_POWER_STATE, AC_PWRST_D3);
+
+	/* Micmute LED state changed by muted/unmute switch */
+	dmi_check_system(micmute_led_dmi_table);
+	if (mc->invert && micmute_led_set) {
+		if (ucontrol->value.integer.value[0] || ucontrol->value.integer.value[1])
+			micmute_led = LED_OFF;
+		else
+			micmute_led = LED_ON;
+		ledtrig_audio_set(LED_AUDIO_MICMUTE, micmute_led);
+	}
 	return 0;
 }
 
-- 
2.25.1