audio-kernel: Synchronize hw vote and unvote requests

HW vote and unvote is currently called from multiple
clients leading to synchronization issues
during SSR/PDR scenarios. Synchronize all the vote requests
by using digital codec resource manager.

Change-Id: I7e63f69ab5d761a3bb4c7ce70bbef2e8bfd76cfb
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>

dsp/digital-cdc-rsc-mgr.c

@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2019-2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/ratelimit.h>
+#include <dsp/digital-cdc-rsc-mgr.h>
+
+struct mutex hw_vote_lock;
+static bool is_init_done;
+
+/**
+ * digital_cdc_rsc_mgr_hw_vote_enable - Enables hw vote in DSP
+ *
+ * @vote_handle: vote handle for which voting needs to be done
+ *
+ * Returns 0 on success or -EINVAL/error code on failure
+ */
+int digital_cdc_rsc_mgr_hw_vote_enable(struct clk* vote_handle)
+{
+	int ret = 0;
+
+	if (!is_init_done || vote_handle == NULL) {
+		pr_err_ratelimited("%s: init failed or vote handle NULL\n",
+				   __func__);
+		return -EINVAL;
+	}
+
+	mutex_lock(&hw_vote_lock);
+	ret = clk_prepare_enable(vote_handle);
+	mutex_unlock(&hw_vote_lock);
+
+	pr_debug("%s: return %d\n", __func__, ret);
+	trace_printk("%s: return %d\n", __func__, ret);
+	return ret;
+}
+EXPORT_SYMBOL(digital_cdc_rsc_mgr_hw_vote_enable);
+
+/**
+ * digital_cdc_rsc_mgr_hw_vote_disable - Disables hw vote in DSP
+ *
+ * @vote_handle: vote handle for which voting needs to be disabled
+ *
+ */
+void digital_cdc_rsc_mgr_hw_vote_disable(struct clk* vote_handle)
+{
+	if (!is_init_done || vote_handle == NULL) {
+		pr_err_ratelimited("%s: init failed or vote handle NULL\n",
+				   __func__);
+		return;
+	}
+
+	mutex_lock(&hw_vote_lock);
+	clk_disable_unprepare(vote_handle);
+	mutex_unlock(&hw_vote_lock);
+	trace_printk("%s\n", __func__);
+}
+EXPORT_SYMBOL(digital_cdc_rsc_mgr_hw_vote_disable);
+
+/**
+ * digital_cdc_rsc_mgr_hw_vote_reset - Resets hw vote count
+ *
+ */
+void digital_cdc_rsc_mgr_hw_vote_reset(struct clk* vote_handle)
+{
+	int count = 0;
+
+	if (!is_init_done || vote_handle == NULL) {
+		pr_err_ratelimited("%s: init failed or vote handle NULL\n",
+				   __func__);
+		return;
+	}
+
+	mutex_lock(&hw_vote_lock);
+	while (__clk_is_enabled(vote_handle)) {
+		clk_disable_unprepare(vote_handle);
+		count++;
+	}
+	pr_debug("%s: Vote count after SSR: %d\n", __func__, count);
+	trace_printk("%s: Vote count after SSR: %d\n", __func__, count);
+
+	while (count--)
+		clk_prepare_enable(vote_handle);
+	mutex_unlock(&hw_vote_lock);
+}
+EXPORT_SYMBOL(digital_cdc_rsc_mgr_hw_vote_reset);
+
+void digital_cdc_rsc_mgr_init()
+{
+	mutex_init(&hw_vote_lock);
+	is_init_done = true;
+}
+
+void digital_cdc_rsc_mgr_exit()
+{
+	mutex_destroy(&hw_vote_lock);
+	is_init_done = false;
+}