[PATCH v2 1/3] mtd: atmel_nand: add NFC status error check

@@ -1572,6 +1572,25 @@ static int atmel_hw_nand_init_params(struct platform_device *pdev,
 	return 0;
 }
 
+static inline u32 nfc_read_status(struct atmel_nand_host *host)
+{
+	u32 err_flags = NFC_SR_DTOE | NFC_SR_UNDEF | NFC_SR_AWB | NFC_SR_ASE;
+	u32 nfc_status = nfc_readl(host->nfc->hsmc_regs, SR);
+
+	if (unlikely(nfc_status & err_flags)) {
+		if (nfc_status & NFC_SR_DTOE)
+			dev_err(host->dev, "NFC: Waiting Nand R/B Timeout Error\n");
+		else if (nfc_status & NFC_SR_UNDEF)
+			dev_err(host->dev, "NFC: Access Undefined Area Error\n");
+		else if (nfc_status & NFC_SR_AWB)
+			dev_err(host->dev, "NFC: Access memory While NFC is busy\n");
+		else if (nfc_status & NFC_SR_ASE)
+			dev_err(host->dev, "NFC: Access memory Size Error\n");
+	}
+
+	return nfc_status;
+}
+
 /* SMC interrupt service routine */
 static irqreturn_t hsmc_interrupt(int irq, void *dev_id)
 {

@@ -1579,7 +1598,7 @@ static irqreturn_t hsmc_interrupt(int irq, void *dev_id)
 	u32 status, mask, pending;
 	irqreturn_t ret = IRQ_HANDLED;
 
-	status = nfc_readl(host->nfc->hsmc_regs, SR);
+	status = nfc_read_status(host);
 	mask = nfc_readl(host->nfc->hsmc_regs, IMR);
 	pending = status & mask;
 

@@ -2210,6 +2229,9 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
 		}
 	}
 
+	nfc_writel(nfc->hsmc_regs, IDR, 0xffffffff);
+	nfc_readl(nfc->hsmc_regs, SR);	/* clear the NFC_SR */
+
 	nfc->is_initialized = true;
 	dev_info(&pdev->dev, "NFC is probed.\n");
 	return 0;

@@ -37,6 +37,10 @@
 #define ATMEL_HSMC_NFC_SR	0x08		/* NFC Status Register */
 #define		NFC_SR_XFR_DONE		(1 << 16)
 #define		NFC_SR_CMD_DONE		(1 << 17)
+#define		NFC_SR_DTOE		(1 << 20)
+#define		NFC_SR_UNDEF		(1 << 21)
+#define		NFC_SR_AWB		(1 << 22)
+#define		NFC_SR_ASE		(1 << 23)
 #define		NFC_SR_RB_EDGE		(1 << 24)
 
 #define ATMEL_HSMC_NFC_IER	0x0c

@@ -1661,11 +1661,19 @@ static int nfc_send_command(struct atmel_nand_host *host,
 
 static int nfc_device_ready(struct mtd_info *mtd)
 {
+	u32 status, mask;
 	struct nand_chip *nand_chip = mtd->priv;
 	struct atmel_nand_host *host = nand_chip->priv;
-	if (!nfc_wait_interrupt(host, NFC_SR_RB_EDGE))
-		return 1;
-	return 0;
+
+	status = nfc_read_status(host);
+	mask = nfc_readl(host->nfc->hsmc_regs, IMR);
+
+	/* The mask should be 0. If not we may lost interrupts */
+	if (unlikely(mask & status))
+		dev_err(host->dev, "Lost the interrupt flags: 0x%08x\n",
+				mask & status);
+
+	return status & NFC_SR_RB_EDGE;
 }
 
 static void nfc_select_chip(struct mtd_info *mtd, int chip)

@@ -97,7 +97,9 @@ struct atmel_nfc {
 	bool			write_by_sram;
 
 	bool			is_initialized;
-	struct completion	comp_nfc;
+	struct completion	comp_ready;
+	struct completion	comp_cmd_done;
+	struct completion	comp_xfer_done;
 
 	/* Point to the sram bank which include readed data via NFC */
 	void __iomem		*data_in_sram;

@@ -1596,44 +1598,80 @@ static irqreturn_t hsmc_interrupt(int irq, void *dev_id)
 {
 	struct atmel_nand_host *host = dev_id;
 	u32 status, mask, pending;
-	irqreturn_t ret = IRQ_HANDLED;
+	irqreturn_t ret = IRQ_NONE;
 
 	status = nfc_read_status(host);
 	mask = nfc_readl(host->nfc->hsmc_regs, IMR);
 	pending = status & mask;
 
 	if (pending & NFC_SR_XFR_DONE) {
-		complete(&host->nfc->comp_nfc);
+		complete(&host->nfc->comp_xfer_done);
 		nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_XFR_DONE);
-	} else if (pending & NFC_SR_RB_EDGE) {
-		complete(&host->nfc->comp_nfc);
+		ret = IRQ_HANDLED;
+	}
+	if (pending & NFC_SR_RB_EDGE) {
+		complete(&host->nfc->comp_ready);
 		nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_RB_EDGE);
-	} else if (pending & NFC_SR_CMD_DONE) {
-		complete(&host->nfc->comp_nfc);
+		ret = IRQ_HANDLED;
+	}
+	if (pending & NFC_SR_CMD_DONE) {
+		complete(&host->nfc->comp_cmd_done);
 		nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_CMD_DONE);
-	} else {
-		ret = IRQ_NONE;
+		ret = IRQ_HANDLED;
 	}
 
 	return ret;
 }
 
 /* NFC(Nand Flash Controller) related functions */
-static int nfc_wait_interrupt(struct atmel_nand_host *host, u32 flag)
+static void nfc_prepare_interrupt(struct atmel_nand_host *host, u32 flag)
 {
-	unsigned long timeout;
-	init_completion(&host->nfc->comp_nfc);
+	if (flag & NFC_SR_XFR_DONE)
+		init_completion(&host->nfc->comp_xfer_done);
+
+	if (flag & NFC_SR_RB_EDGE)
+		init_completion(&host->nfc->comp_ready);
+
+	if (flag & NFC_SR_CMD_DONE)
+		init_completion(&host->nfc->comp_cmd_done);
 
 	/* Enable interrupt that need to wait for */
 	nfc_writel(host->nfc->hsmc_regs, IER, flag);
+}
 
-	timeout = wait_for_completion_timeout(&host->nfc->comp_nfc,
-			msecs_to_jiffies(NFC_TIME_OUT_MS));
-	if (timeout)
-		return 0;
+static int nfc_wait_interrupt(struct atmel_nand_host *host, u32 flag)
+{
+	int i, index = 0;
+	struct completion *comp[3];	/* Support 3 interrupt completion */
+
+	if (flag & NFC_SR_XFR_DONE)
+		comp[index++] = &host->nfc->comp_xfer_done;
+
+	if (flag & NFC_SR_RB_EDGE)
+		comp[index++] = &host->nfc->comp_ready;
 
-	/* Time out to wait for the interrupt */
+	if (flag & NFC_SR_CMD_DONE)
+		comp[index++] = &host->nfc->comp_cmd_done;
+
+	if (index == 0) {
+		dev_err(host->dev, "Unkown interrupt flag: 0x%08x\n", flag);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < index; i++) {
+		if (wait_for_completion_timeout(comp[i],
+				msecs_to_jiffies(NFC_TIME_OUT_MS)))
+			continue;	/* wait for next completion */
+		else
+			goto err_timeout;
+	}
+
+	return 0;
+
+err_timeout:
 	dev_err(host->dev, "Time out to wait for interrupt: 0x%08x\n", flag);
+	/* Disable the interrupt as it is not handled by interrupt handler */
+	nfc_writel(host->nfc->hsmc_regs, IDR, flag);
 	return -ETIMEDOUT;
 }
 

@@ -1641,6 +1679,9 @@ static int nfc_send_command(struct atmel_nand_host *host,
 	unsigned int cmd, unsigned int addr, unsigned char cycle0)
 {
 	unsigned long timeout;
+	u32 flag = NFC_SR_CMD_DONE;
+	flag |= cmd & NFCADDR_CMD_DATAEN ? NFC_SR_XFR_DONE : 0;
+
 	dev_dbg(host->dev,
 		"nfc_cmd: 0x%08x, addr1234: 0x%08x, cycle0: 0x%02x\n",
 		cmd, addr, cycle0);

@@ -1654,9 +1695,11 @@ static int nfc_send_command(struct atmel_nand_host *host,
 			return -ETIMEDOUT;
 		}
 	}
+
+	nfc_prepare_interrupt(host, flag);
 	nfc_writel(host->nfc->hsmc_regs, CYCLE0, cycle0);
 	nfc_cmd_addr1234_writel(cmd, addr, host->nfc->base_cmd_regs);
-	return nfc_wait_interrupt(host, NFC_SR_CMD_DONE);
+	return nfc_wait_interrupt(host, flag);
 }
 
 static int nfc_device_ready(struct mtd_info *mtd)

@@ -1822,10 +1865,6 @@ static void nfc_nand_command(struct mtd_info *mtd, unsigned int command,
 	nfc_addr_cmd = cmd1 | cmd2 | vcmd2 | acycle | csid | dataen | nfcwr;
 	nfc_send_command(host, nfc_addr_cmd, addr1234, cycle0);
 
-	if (dataen == NFCADDR_CMD_DATAEN)
-		if (nfc_wait_interrupt(host, NFC_SR_XFR_DONE))
-			dev_err(host->dev, "something wrong, No XFR_DONE interrupt comes.\n");
-
 	/*
 	 * Program and erase have their own busy handlers status, sequential
 	 * in, and deplete1 need no delay.

@@ -1850,6 +1889,7 @@ static void nfc_nand_command(struct mtd_info *mtd, unsigned int command,
 		}
 		/* fall through */
 	default:
+		nfc_prepare_interrupt(host, NFC_SR_RB_EDGE);
 		nfc_wait_interrupt(host, NFC_SR_RB_EDGE);
 	}
 }