From baf3d1b4fcee7dafdbc2c26725def2c2f9580f95 Mon Sep 17 00:00:00 2001
From: Ravi Vembu <raviv@motorola.com>
Date: Thu, 21 Jun 2018 16:49:42 -0500
Subject: [PATCH] madera: Add ref clk for codec

Enable the ref clk when the codec is not in reset.

Mot-CRs-Fixed: (CR)
Change-Id: Ic6d0d3f869621b193747f7ba309c2fb18b6a2573
Signed-off-by: Ravi Vembu <raviv@motorola.com>
Reviewed-on: https://gerrit.mot.com/1197391
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Submit-Approved: Jira Key
---
 drivers/mfd/madera-core.c       | 54 ++++++++++++++++++++++++++++++++-
 include/linux/mfd/madera/core.h |  3 ++
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c
index a840f4ae5cc2..26a5a1f4f7c0 100644
--- a/drivers/mfd/madera-core.c
+++ b/drivers/mfd/madera-core.c
@@ -148,6 +148,53 @@ const struct of_device_id madera_of_match[] = {
 EXPORT_SYMBOL_GPL(madera_of_match);
 #endif
 
+/*
+ * Routine to enable clock.
+ * this routine can be extended to select from multiple
+ * sources based on clk_src_name.
+ */
+static int madera_clock_select(struct madera *madera)
+{
+	int r = 0;
+
+	madera->m_clk = clk_get(madera->dev, "cdc_mclk2");
+
+	if (madera->m_clk == NULL)
+		goto err_clk;
+
+	if (madera->clk_run == false)
+		r = clk_prepare_enable(madera->m_clk);
+
+	if (r)
+		goto err_clk;
+
+	madera->clk_run = true;
+
+	return r;
+
+err_clk:
+	dev_err(madera->dev, "Error enabling Ref Clock\n");
+	r = -1;
+	return r;
+}
+
+/*
+ * Routine to disable clocks
+ */
+static int madera_clock_deselect(struct madera *madera)
+{
+	int r = -1;
+
+	if (madera->m_clk != NULL) {
+		if (madera->clk_run == true) {
+			clk_disable_unprepare(madera->m_clk);
+			madera->clk_run = false;
+		}
+		return 0;
+	}
+	return r;
+}
+
 static int madera_poll_reg(struct madera *madera,
 			   int timeout, unsigned int reg,
 			   unsigned int mask, unsigned int target)
@@ -724,6 +771,8 @@ int madera_dev_init(struct madera *madera)
 		goto err_devs;
 	}
 
+	madera_clock_select(madera);
+
 	/**
 	 * Don't use devres here because the only device we have to get
 	 * against is the MFD device and DCVDD will likely be supplied by
@@ -734,7 +783,7 @@ int madera_dev_init(struct madera *madera)
 	if (IS_ERR(madera->dcvdd)) {
 		ret = PTR_ERR(madera->dcvdd);
 		dev_err(dev, "Failed to request DCVDD: %d\n", ret);
-		goto err_devs;
+		goto err_ref_clk;
 	}
 
 	madera->dcvdd_notifier.notifier_call = madera_dcvdd_notify;
@@ -931,6 +980,8 @@ err_notifier:
 	regulator_unregister_notifier(madera->dcvdd, &madera->dcvdd_notifier);
 err_dcvdd:
 	regulator_put(madera->dcvdd);
+err_ref_clk:
+	madera_clock_deselect(madera);
 err_devs:
 	mfd_remove_devices(dev);
 	return ret;
@@ -950,6 +1001,7 @@ int madera_dev_exit(struct madera *madera)
 
 	regulator_bulk_disable(madera->num_core_supplies,
 			       madera->core_supplies);
+	madera_clock_deselect(madera);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(madera_dev_exit);
diff --git a/include/linux/mfd/madera/core.h b/include/linux/mfd/madera/core.h
index 4c28b047c52f..33dae31768a4 100644
--- a/include/linux/mfd/madera/core.h
+++ b/include/linux/mfd/madera/core.h
@@ -17,6 +17,7 @@
 #include <linux/regulator/consumer.h>
 #include <linux/mfd/madera/pdata.h>
 #include <linux/irqchip/irq-madera.h>
+#include <linux/clk.h>
 
 enum madera_type {
 	CS47L35 = 1,
@@ -72,6 +73,8 @@ struct madera {
 	struct mutex reg_setting_lock;
 
 	struct blocking_notifier_head notifier;
+	struct  clk   *m_clk;
+	bool    clk_run;
 };
 
 extern int madera_of_read_uint_array(struct madera *madera, const char *prop,