asoc: Add support for sysfs based SSR

Create sysfs node for SSR.

Change-Id: Ia181a51ae969632b739676b4b95e2bf0f50ce432

asoc/msm_common.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 2020, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -25,6 +25,11 @@
 
 #include "msm_common.h"
 
+struct snd_card_pdata {
+	struct kobject snd_card_kobj;
+	int card_status;
+}*snd_card_pdata;
+
 #define to_asoc_mach_common_pdata(kobj) \
 	container_of((kobj), struct msm_common_pdata, aud_dev_kobj)
 
@@ -32,12 +37,19 @@
 #define DEVICE_DISABLE 0
 
 #define ARRAY_SZ 21
+#define BUF_SZ 32
+#define DIR_SZ 10
 
 static struct attribute device_state_attr = {
 	.name = "state",
 	.mode = 0660,
 };
 
+static struct attribute card_state_attr = {
+	.name = "card_state",
+	.mode = 0660,
+};
+
 #define MAX_PORT 20
 #define CODEC_CHMAP "Channel Map"
 
@@ -124,6 +136,65 @@ done:
 	return ret;
 }
 
+int snd_card_notify_user(int card_status)
+{
+	snd_card_pdata->card_status = card_status;
+	sysfs_notify(&snd_card_pdata->snd_card_kobj, NULL, "card_state");
+	return 0;
+}
+
+static ssize_t snd_card_sysfs_show(struct kobject *kobj,
+		struct attribute *attr, char *buf)
+{
+	return snprintf(buf, BUF_SZ, "%d", snd_card_pdata->card_status);
+}
+
+static ssize_t snd_card_sysfs_store(struct kobject *kobj,
+		struct attribute *attr, const char *buf, size_t count)
+{
+	sscanf(buf, "%d", &snd_card_pdata->card_status);
+	sysfs_notify(&snd_card_pdata->snd_card_kobj, NULL, "card_state");
+	return 0;
+}
+
+static const struct sysfs_ops snd_card_sysfs_ops = {
+	.show = snd_card_sysfs_show,
+	.store = snd_card_sysfs_store,
+};
+
+static struct kobj_type snd_card_ktype = {
+	.sysfs_ops = &snd_card_sysfs_ops,
+};
+
+int snd_card_sysfs_init(void)
+{
+	int ret = 0;
+	char dir[DIR_SZ] = "snd_card";
+
+	snd_card_pdata = kcalloc(1, sizeof(struct snd_card_pdata), GFP_KERNEL);
+	ret = kobject_init_and_add(&snd_card_pdata->snd_card_kobj, &snd_card_ktype,
+		kernel_kobj, dir);
+	if (ret < 0) {
+		pr_err("%s: Failed to add kobject %s, err = %d\n",
+			__func__, dir, ret);
+		goto done;
+	}
+
+	ret = sysfs_create_file(&snd_card_pdata->snd_card_kobj, &card_state_attr);
+	if (ret < 0) {
+		pr_err("%s: Failed to add snd_card sysfs entry to %s\n",
+			__func__, dir);
+		goto fail_create_file;
+	}
+
+	return ret;
+
+fail_create_file:
+	kobject_put(&snd_card_pdata->snd_card_kobj);
+done:
+	return ret;
+}
+
 static void check_userspace_service_state(struct snd_soc_pcm_runtime *rtd,
 						struct msm_common_pdata *pdata)
 {

asoc/msm_common.h

@@ -1,4 +1,4 @@
-/* Copyright (c) 2020, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -41,11 +41,14 @@ struct msm_common_pdata {
 	atomic_t mi2s_gpio_ref_cnt[MI2S_TDM_AUXPCM_MAX];
 };
 
+int snd_card_notify_user(int card_status);
 struct msm_common_pdata *msm_common_get_pdata(struct snd_soc_card *card);
 
 void msm_common_set_pdata(struct snd_soc_card *card,
 			  struct msm_common_pdata *pdata);
 
+int snd_card_sysfs_init(void);
+
 int msm_common_snd_startup(struct snd_pcm_substream *substream);
 
 void msm_common_snd_shutdown(struct snd_pcm_substream *substream);

asoc/waipio.c

@@ -1483,9 +1483,7 @@ static int waipio_ssr_enable(struct device *dev, void *data)
 		dev_dbg(dev, "%s: TODO \n", __func__);
 	}
 
-#if IS_ENABLED(CONFIG_AUDIO_QGKI)
-	snd_soc_card_change_online_state(card, 1);
-#endif /* CONFIG_AUDIO_QGKI */
+	snd_card_notify_user(1);
 	dev_dbg(dev, "%s: setting snd_card to ONLINE\n", __func__);
 
 err:
@@ -1503,9 +1501,7 @@ static void waipio_ssr_disable(struct device *dev, void *data)
 	}
 
 	dev_dbg(dev, "%s: setting snd_card to OFFLINE\n", __func__);
-#if IS_ENABLED(CONFIG_AUDIO_QGKI)
-	snd_soc_card_change_online_state(card, 0);
-#endif /* CONFIG_AUDIO_QGKI */
+	snd_card_notify_user(0);
 
 	if (!strcmp(card->name, "waipio-stub-snd-card")) {
 		/* TODO */
@@ -1736,7 +1732,19 @@ static struct platform_driver waipio_asoc_machine_driver = {
 	.probe = msm_asoc_machine_probe,
 	.remove = msm_asoc_machine_remove,
 };
-module_platform_driver(waipio_asoc_machine_driver);
+
+static int __init msm_asoc_machine_init(void)
+{
+	snd_card_sysfs_init();
+	return platform_driver_register(&waipio_asoc_machine_driver);
+}
+module_init(msm_asoc_machine_init);
+
+static void __exit msm_asoc_machine_exit(void)
+{
+	platform_driver_unregister(&waipio_asoc_machine_driver);
+}
+module_exit(msm_asoc_machine_exit);
 
 MODULE_SOFTDEP("pre: bt_fm_slim");
 MODULE_DESCRIPTION("ALSA SoC msm");