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Commit a47bfd2e authored by Ivo Clarysse's avatar Ivo Clarysse Committed by David Woodhouse
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mtd: mxc_nand: support i.MX21 



On i.MX21 SoCs, if the NFC_CONFIG1:NFC_INT_MASK bit is set,
NFC_CONFIG2:NFC_INT always reads out zero, even if an
operation is completed.  This patch uses enable_irq and
disable_irq_nosync instead of NFC_CONFIG1:NFC_INT_MASK to
mask NFC interrupts.  This allows NFC_CONFIG2:NFC_INT to also
be used to detect operation completion on i.MX21.

The i.MX21 NFC does not signal reset completion using
NFC_CONFIG1:NFC_INT_MASK, so instead reset completion is
tested by checking if NFC_CONFIG2 becomes 0.

Signed-off-by: default avatarIvo Clarysse <ivo.clarysse@gmail.com>
Acked-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent d4840180

drivers/mtd/nand/mxc_nand.c

+25 −16
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ 
#define DRIVER_NAME "mxc_nand"



#define nfc_is_v21()		(cpu_is_mx25() || cpu_is_mx35())

#define nfc_is_v1()		(cpu_is_mx31() || cpu_is_mx27())

#define nfc_is_v1()		(cpu_is_mx31() || cpu_is_mx27() || cpu_is_mx21())



/* Addresses for NFC registers */

#define NFC_BUF_SIZE		0xE00
@@ -168,11 +168,7 @@ static irqreturn_t mxc_nfc_irq(int irq, void *dev_id) 
{

	struct mxc_nand_host *host = dev_id;



	uint16_t tmp;



	tmp = readw(host->regs + NFC_CONFIG1);

	tmp |= NFC_INT_MSK; /* Disable interrupt */

	writew(tmp, host->regs + NFC_CONFIG1);

	disable_irq_nosync(irq);



	wake_up(&host->irq_waitq);
@@ -184,15 +180,13 @@ static irqreturn_t mxc_nfc_irq(int irq, void *dev_id) 
 */

static void wait_op_done(struct mxc_nand_host *host, int useirq)

{

	uint32_t tmp;

	int max_retries = 2000;

	uint16_t tmp;

	int max_retries = 8000;



	if (useirq) {

		if ((readw(host->regs + NFC_CONFIG2) & NFC_INT) == 0) {



			tmp = readw(host->regs + NFC_CONFIG1);

			tmp  &= ~NFC_INT_MSK;	/* Enable interrupt */

			writew(tmp, host->regs + NFC_CONFIG1);

			enable_irq(host->irq);



			wait_event(host->irq_waitq,

				readw(host->regs + NFC_CONFIG2) & NFC_INT);
@@ -226,9 +220,24 @@ static void send_cmd(struct mxc_nand_host *host, uint16_t cmd, int useirq) 
	writew(cmd, host->regs + NFC_FLASH_CMD);

	writew(NFC_CMD, host->regs + NFC_CONFIG2);



	if (cpu_is_mx21() && (cmd == NAND_CMD_RESET)) {

		int max_retries = 100;

		/* Reset completion is indicated by NFC_CONFIG2 */

		/* being set to 0 */

		while (max_retries-- > 0) {

			if (readw(host->regs + NFC_CONFIG2) == 0) {

				break;

			}

			udelay(1);

		}

		if (max_retries < 0)

			DEBUG(MTD_DEBUG_LEVEL0, "%s: RESET failed\n",

			      __func__);

	} else {

		/* Wait for operation to complete */

		wait_op_done(host, useirq);

	}

}



/* This function sends an address (or partial address) to the

 * NAND device. The address is used to select the source/destination for
@@ -548,9 +557,9 @@ static void preset(struct mtd_info *mtd) 
	struct mxc_nand_host *host = nand_chip->priv;

	uint16_t tmp;



	/* disable interrupt, disable spare enable */

	/* enable interrupt, disable spare enable */

	tmp = readw(host->regs + NFC_CONFIG1);

	tmp |= NFC_INT_MSK;

	tmp &= ~NFC_INT_MSK;

	tmp &= ~NFC_SP_EN;

	if (nand_chip->ecc.mode == NAND_ECC_HW) {

		tmp |= NFC_ECC_EN;
@@ -820,7 +829,7 @@ static int __init mxcnd_probe(struct platform_device *pdev) 


	host->irq = platform_get_irq(pdev, 0);



	err = request_irq(host->irq, mxc_nfc_irq, 0, DRIVER_NAME, host);

	err = request_irq(host->irq, mxc_nfc_irq, IRQF_DISABLED, DRIVER_NAME, host);

	if (err)

		goto eirq;