From 230e822ef5530322f20f591c1933e7be0d2f9954 Mon Sep 17 00:00:00 2001
From: Shuai Li <shuai.li@amlogic.com>
Date: Thu, 8 Aug 2019 16:17:32 +0800
Subject: [PATCH] audio: add enable count for PDM module [1/1]

PD#IPTV-3723

Problem:
One use case is PDM module is sendig data
to both PDM device and LOOPBACK device.
Close one will make another useless.

Solution:
Add management of the PDM module by
a enable count.

Verify:
SM1.

Change-Id: Iceeb756c02671b16dbc3c49a9b793a50e6e559b5
Signed-off-by: Shuai Li <shuai.li@amlogic.com>
---
 sound/soc/amlogic/auge/pdm_hw.c | 35 ++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/sound/soc/amlogic/auge/pdm_hw.c b/sound/soc/amlogic/auge/pdm_hw.c
index 4a861ac107fb..fd5116b9c194 100644
--- a/sound/soc/amlogic/auge/pdm_hw.c
+++ b/sound/soc/amlogic/auge/pdm_hw.c
@@ -19,28 +19,39 @@
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/string.h>
-/*#include <linux/delay.h>*/
+#include <linux/spinlock.h>
 
 #include "pdm_hw.h"
 #include "regs.h"
 #include "iomap.h"
 #include "pdm_hw_coeff.c"
 
+static DEFINE_SPINLOCK(pdm_lock);
+static unsigned long pdm_enable_cnt;
 void pdm_enable(int is_enable)
 {
-	if (is_enable) {
-		aml_pdm_update_bits(
-			PDM_CTRL,
-			0x1 << 31,
-			is_enable << 31);
-	} else {
-		aml_pdm_update_bits(
-			PDM_CTRL,
-			0x1 << 31 | 0x1 << 16,
-			0 << 31 | 0 << 16);
+	unsigned long flags;
 
-		/*udelay(1000);*/
+	spin_lock_irqsave(&pdm_lock, flags);
+	if (is_enable) {
+		if (pdm_enable_cnt == 0)
+			aml_pdm_update_bits(
+				PDM_CTRL,
+				0x1 << 31,
+				is_enable << 31);
+		pdm_enable_cnt++;
+	} else {
+		if (WARN_ON(pdm_enable_cnt == 0))
+			goto exit;
+		if (--pdm_enable_cnt == 0)
+			aml_pdm_update_bits(
+				PDM_CTRL,
+				0x1 << 31 | 0x1 << 16,
+				0 << 31 | 0 << 16);
 	}
+
+exit:
+	spin_unlock_irqrestore(&pdm_lock, flags);
 }
 
 void pdm_fifo_reset(void)