ENGR00126278 NAND:nfc_clk count not zero after multi-cs NAND scan

In fact, NAND driver always do clk_enable when use NAND
and clk_disable when not use. But there is one open issue
in nand_base.c community code for multiple NAND scan, it
call multiple chip->select_chip(mtd, i); but only call one
time for chip->select_chip(mtd, -1); which will cause the nfc
clock count not equal to zero after multiple cs NAND scan

Signed-off-by:Jason Liu <r64343@freescale.com>

1 files changed, 34 insertions, 7 deletions

diff --git a/drivers/mtd/nand/mxc_nd2.c b/drivers/mtd/nand/mxc_nd2.c
index 07eb120d0c24..18213448abf8 100644
--- a/drivers/mtd/nand/mxc_nd2.c
+++ b/drivers/mtd/nand/mxc_nd2.c
@@ -40,6 +40,7 @@ struct mxc_mtd_s {
 	struct mtd_partition *parts;
 	struct device *dev;
 	int disable_bi_swap; /* disable bi swap */
+	int clk_active;
 };
 
 static struct mxc_mtd_s *mxc_nand_data;
@@ -791,6 +792,30 @@ static int mxc_nand_verify_buf(struct mtd_info *mtd, const u_char * buf,
 }
 
 /*!
+ * This function will enable NFC clock
+ *
+ */
+static inline void mxc_nand_clk_enable(void)
+{
+	if (!mxc_nand_data->clk_active) {
+		clk_enable(nfc_clk);
+		mxc_nand_data->clk_active = 1;
+	}
+}
+
+/*!
+ * This function will disable NFC clock
+ *
+ */
+static inline void mxc_nand_clk_disable(void)
+{
+	if (mxc_nand_data->clk_active) {
+		clk_disable(nfc_clk);
+		mxc_nand_data->clk_active = 0;
+	}
+}
+
+/*!
  * This function is used by upper layer for select and deselect of the NAND
  * chip
  *
@@ -803,13 +828,14 @@ static void mxc_nand_select_chip(struct mtd_info *mtd, int chip)
 	switch (chip) {
 	case -1:
 		/* Disable the NFC clock */
-		clk_disable(nfc_clk);
+		mxc_nand_clk_disable();
+
 		break;
-	case 0 ... 7:
+	case 0 ... NFC_GET_MAXCHIP_SP():
 		/* Enable the NFC clock */
-		clk_enable(nfc_clk);
-
+		mxc_nand_clk_enable();
 		NFC_SET_NFC_ACTIVE_CS(chip);
+
 		break;
 
 	default:
@@ -1438,6 +1464,7 @@ static int __devinit mxcnd_probe(struct platform_device *pdev)
 
 	nfc_clk = clk_get(&pdev->dev, "nfc_clk");
 	clk_enable(nfc_clk);
+	mxc_nand_data->clk_active = 1;
 
 	if (hardware_ecc) {
 		this->ecc.read_page = mxc_nand_read_page;
@@ -1523,7 +1550,7 @@ static int __exit mxcnd_remove(struct platform_device *pdev)
 	manage_sysfs_files(false);
 	mxc_free_buf();
 
-	clk_disable(nfc_clk);
+	mxc_nand_clk_disable();
 	clk_put(nfc_clk);
 	platform_set_drvdata(pdev, NULL);
 
@@ -1554,7 +1581,7 @@ static int mxcnd_suspend(struct platform_device *pdev, pm_message_t state)
 	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND2 : NAND suspend\n");
 
 	/* Disable the NFC clock */
-	clk_disable(nfc_clk);
+	mxc_nand_clk_disable();
 
 	return 0;
 }
@@ -1573,7 +1600,7 @@ static int mxcnd_resume(struct platform_device *pdev)
 	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND2 : NAND resume\n");
 
 	/* Enable the NFC clock */
-	clk_enable(nfc_clk);
+	mxc_nand_clk_enable();
 
 	return 0;
 }