[GIT PULL] mxc nand patch for -rc

[GIT PULL] mxc nand patch for -rc

[Sascha Hauer]

Hi David, Artem,

I originally wanted to delay this patch to the next merge window, but
now I realized that the mxc-nand driver is not working anymore, so please
pull the following to fix it.

Sascha

The following changes since commit 9c03f1622af051004416dd3e24d8a0fa31e34178:

  Merge ssh://master.kernel.org/home/hpa/tree/sec (2010-09-14 17:07:51 -0700)

are available in the git repository at:

  git://git.pengutronix.de/git/imx/linux-2.6.git mtd-imx-nand

Sascha Hauer (1):
      mtd: mxc_nand: do not depend on disabling the irq in the interrupt handler

 drivers/mtd/nand/mxc_nand.c |   92 ++++++++++++++++++++++++++++++++++++++----
 1 files changed, 83 insertions(+), 9 deletions(-)

[PATCH] mtd: mxc_nand: do not depend on disabling the irq in the interrupt handler

[Sascha Hauer]

This patch reverts the driver to enabling/disabling the NFC interrupt
mask rather than enabling/disabling the system interrupt. This cleans
up the driver so that it doesn't rely on interrupts being disabled
within the interrupt handler.
For i.MX21 we keep the current behaviour, that is calling
enable_irq/disable_irq_nosync to enable/disable interrupts.
This patch is based on earlier work by John Ogness.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: John Ogness <john.ogness@linutronix.de>
Tested-by: John Ogness <john.ogness@linutronix.de>
---
 drivers/mtd/nand/mxc_nand.c |   92 ++++++++++++++++++++++++++++++++++++++----
 1 files changed, 83 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index b2828e8..214b03a 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -30,6 +30,8 @@
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/completion.h>
 
 #include <asm/mach/flash.h>
 #include <mach/mxc_nand.h>
@@ -151,7 +153,7 @@ struct mxc_nand_host {
 	int			irq;
 	int			eccsize;
 
-	wait_queue_head_t	irq_waitq;
+	struct completion	op_completion;
 
 	uint8_t			*data_buf;
 	unsigned int		buf_start;
@@ -164,6 +166,7 @@ struct mxc_nand_host {
 	void			(*send_read_id)(struct mxc_nand_host *);
 	uint16_t		(*get_dev_status)(struct mxc_nand_host *);
 	int			(*check_int)(struct mxc_nand_host *);
+	void			(*irq_control)(struct mxc_nand_host *, int);
 };
 
 /* OOB placement block for use with hardware ecc generation */
@@ -216,9 +219,12 @@ static irqreturn_t mxc_nfc_irq(int irq, void *dev_id)
 {
 	struct mxc_nand_host *host = dev_id;
 
-	disable_irq_nosync(irq);
+	if (!host->check_int(host))
+		return IRQ_NONE;
 
-	wake_up(&host->irq_waitq);
+	host->irq_control(host, 0);
+
+	complete(&host->op_completion);
 
 	return IRQ_HANDLED;
 }
@@ -245,11 +251,54 @@ static int check_int_v1_v2(struct mxc_nand_host *host)
 	if (!(tmp & NFC_V1_V2_CONFIG2_INT))
 		return 0;
 
-	writew(tmp & ~NFC_V1_V2_CONFIG2_INT, NFC_V1_V2_CONFIG2);
+	if (!cpu_is_mx21())
+		writew(tmp & ~NFC_V1_V2_CONFIG2_INT, NFC_V1_V2_CONFIG2);
 
 	return 1;
 }
 
+/*
+ * It has been observed that the i.MX21 cannot read the CONFIG2:INT bit
+ * if interrupts are masked (CONFIG1:INT_MSK is set). To handle this, the
+ * driver can enable/disable the irq line rather than simply masking the
+ * interrupts.
+ */
+static void irq_control_mx21(struct mxc_nand_host *host, int activate)
+{
+	if (activate)
+		enable_irq(host->irq);
+	else
+		disable_irq_nosync(host->irq);
+}
+
+static void irq_control_v1_v2(struct mxc_nand_host *host, int activate)
+{
+	uint16_t tmp;
+
+	tmp = readw(NFC_V1_V2_CONFIG1);
+
+	if (activate)
+		tmp &= ~NFC_V1_V2_CONFIG1_INT_MSK;
+	else
+		tmp |= NFC_V1_V2_CONFIG1_INT_MSK;
+
+	writew(tmp, NFC_V1_V2_CONFIG1);
+}
+
+static void irq_control_v3(struct mxc_nand_host *host, int activate)
+{
+	uint32_t tmp;
+
+	tmp = readl(NFC_V3_CONFIG2);
+
+	if (activate)
+		tmp &= ~NFC_V3_CONFIG2_INT_MSK;
+	else
+		tmp |= NFC_V3_CONFIG2_INT_MSK;
+
+	writel(tmp, NFC_V3_CONFIG2);
+}
+
 /* This function polls the NANDFC to wait for the basic operation to
  * complete by checking the INT bit of config2 register.
  */
@@ -259,10 +308,9 @@ static void wait_op_done(struct mxc_nand_host *host, int useirq)
 
 	if (useirq) {
 		if (!host->check_int(host)) {
-
-			enable_irq(host->irq);
-
-			wait_event(host->irq_waitq, host->check_int(host));
+			INIT_COMPLETION(host->op_completion);
+			host->irq_control(host, 1);
+			wait_for_completion(&host->op_completion);
 		}
 	} else {
 		while (max_retries-- > 0) {
@@ -799,6 +847,7 @@ static void preset_v3(struct mtd_info *mtd)
 		NFC_V3_CONFIG2_2CMD_PHASES |
 		NFC_V3_CONFIG2_SPAS(mtd->oobsize >> 1) |
 		NFC_V3_CONFIG2_ST_CMD(0x70) |
+		NFC_V3_CONFIG2_INT_MSK |
 		NFC_V3_CONFIG2_NUM_ADDR_PHASE0;
 
 	if (chip->ecc.mode == NAND_ECC_HW)
@@ -1024,6 +1073,10 @@ static int __init mxcnd_probe(struct platform_device *pdev)
 		host->send_read_id = send_read_id_v1_v2;
 		host->get_dev_status = get_dev_status_v1_v2;
 		host->check_int = check_int_v1_v2;
+		if (cpu_is_mx21())
+			host->irq_control = irq_control_mx21;
+		else
+			host->irq_control = irq_control_v1_v2;
 	}
 
 	if (nfc_is_v21()) {
@@ -1062,6 +1115,7 @@ static int __init mxcnd_probe(struct platform_device *pdev)
 		host->send_read_id = send_read_id_v3;
 		host->check_int = check_int_v3;
 		host->get_dev_status = get_dev_status_v3;
+		host->irq_control = irq_control_v3;
 		oob_smallpage = &nandv2_hw_eccoob_smallpage;
 		oob_largepage = &nandv2_hw_eccoob_largepage;
 	} else
@@ -1093,14 +1147,34 @@ static int __init mxcnd_probe(struct platform_device *pdev)
 		this->options |= NAND_USE_FLASH_BBT;
 	}
 
-	init_waitqueue_head(&host->irq_waitq);
+	init_completion(&host->op_completion);
 
 	host->irq = platform_get_irq(pdev, 0);
 
+	/*
+	 * mask the interrupt. For i.MX21 explicitely call
+	 * irq_control_v1_v2 to use the mask bit. We can't call
+	 * disable_irq_nosync() for an interrupt we do not own yet.
+	 */
+	if (cpu_is_mx21())
+		irq_control_v1_v2(host, 0);
+	else
+		host->irq_control(host, 0);
+
 	err = request_irq(host->irq, mxc_nfc_irq, IRQF_DISABLED, DRIVER_NAME, host);
 	if (err)
 		goto eirq;
 
+	host->irq_control(host, 0);
+
+	/*
+	 * Now that the interrupt is disabled make sure the interrupt
+	 * mask bit is cleared on i.MX21. Otherwise we can't read
+	 * the interrupt status bit on this machine.
+	 */
+	if (cpu_is_mx21())
+		irq_control_v1_v2(host, 1);
+
 	/* first scan to find the device and get the page size */
 	if (nand_scan_ident(mtd, 1, NULL)) {
 		err = -ENXIO;
-- 
1.7.2.3

Re: [PATCH] mtd: mxc_nand: do not depend on disabling the irq in the interrupt handler

[Artem Bityutskiy]

On Tue, 2010-09-21 at 09:40 +0200, Sascha Hauer wrote:
> This patch reverts the driver to enabling/disabling the NFC interrupt
> mask rather than enabling/disabling the system interrupt. This cleans
> up the driver so that it doesn't rely on interrupts being disabled
> within the interrupt handler.
> For i.MX21 we keep the current behaviour, that is calling
> enable_irq/disable_irq_nosync to enable/disable interrupts.
> This patch is based on earlier work by John Ogness.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> Acked-by: John Ogness <john.ogness@linutronix.de>
> Tested-by: John Ogness <john.ogness@linutronix.de>

I've created l2-mtd-2.6.git/for-2.6.36 branch, pushed your patch there,
pinged dwmw2 for you. I do not give you any guarantees this will reach
2.6.36, you have to ping dwmw2.

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)

Re: [PATCH] mtd: mxc_nand: do not depend on disabling the irq in the interrupt handler

[Sascha Hauer]

David,

On Thu, Sep 23, 2010 at 02:16:52PM +0300, Artem Bityutskiy wrote:
> On Tue, 2010-09-21 at 09:40 +0200, Sascha Hauer wrote:
> > This patch reverts the driver to enabling/disabling the NFC interrupt
> > mask rather than enabling/disabling the system interrupt. This cleans
> > up the driver so that it doesn't rely on interrupts being disabled
> > within the interrupt handler.
> > For i.MX21 we keep the current behaviour, that is calling
> > enable_irq/disable_irq_nosync to enable/disable interrupts.
> > This patch is based on earlier work by John Ogness.
> > 
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > Acked-by: John Ogness <john.ogness@linutronix.de>
> > Tested-by: John Ogness <john.ogness@linutronix.de>
> 
> I've created l2-mtd-2.6.git/for-2.6.36 branch, pushed your patch there,
> pinged dwmw2 for you. I do not give you any guarantees this will reach
> 2.6.36, you have to ping dwmw2.

Any chance to get this in? The mxc-nand driver is nonfunctional at the
moment and 2.6.36 is getting closer.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
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Re: [PATCH] mtd: mxc_nand: do not depend on disabling the irq in the interrupt handler

[Eric Bénard]

Le 29/09/2010 09:28, Sascha Hauer a écrit :
> David,
>
> On Thu, Sep 23, 2010 at 02:16:52PM +0300, Artem Bityutskiy wrote:
>> On Tue, 2010-09-21 at 09:40 +0200, Sascha Hauer wrote:
>>> This patch reverts the driver to enabling/disabling the NFC interrupt
>>> mask rather than enabling/disabling the system interrupt. This cleans
>>> up the driver so that it doesn't rely on interrupts being disabled
>>> within the interrupt handler.
>>> For i.MX21 we keep the current behaviour, that is calling
>>> enable_irq/disable_irq_nosync to enable/disable interrupts.
>>> This patch is based on earlier work by John Ogness.
>>>
>>> Signed-off-by: Sascha Hauer<s.hauer@pengutronix.de>
>>> Acked-by: John Ogness<john.ogness@linutronix.de>
>>> Tested-by: John Ogness<john.ogness@linutronix.de>
>>
>> I've created l2-mtd-2.6.git/for-2.6.36 branch, pushed your patch there,
>> pinged dwmw2 for you. I do not give you any guarantees this will reach
>> 2.6.36, you have to ping dwmw2.
>
> Any chance to get this in? The mxc-nand driver is nonfunctional at the
> moment and 2.6.36 is getting closer.
>
Acked-by: Eric Bénard <eric@eukrea.com>
Tested-by: Eric B2nard <eric@eukrea.com>

Eric

Re: [PATCH] mtd: mxc_nand: do not depend on disabling the irq in the interrupt handler

[Uwe Kleine-König]

On Wed, Sep 29, 2010 at 09:28:43AM +0200, Sascha Hauer wrote:
> David,
> 
> On Thu, Sep 23, 2010 at 02:16:52PM +0300, Artem Bityutskiy wrote:
> > On Tue, 2010-09-21 at 09:40 +0200, Sascha Hauer wrote:
> > > This patch reverts the driver to enabling/disabling the NFC interrupt
> > > mask rather than enabling/disabling the system interrupt. This cleans
> > > up the driver so that it doesn't rely on interrupts being disabled
> > > within the interrupt handler.
> > > For i.MX21 we keep the current behaviour, that is calling
> > > enable_irq/disable_irq_nosync to enable/disable interrupts.
> > > This patch is based on earlier work by John Ogness.
> > > 
> > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > > Acked-by: John Ogness <john.ogness@linutronix.de>
> > > Tested-by: John Ogness <john.ogness@linutronix.de>
> > 
> > I've created l2-mtd-2.6.git/for-2.6.36 branch, pushed your patch there,
> > pinged dwmw2 for you. I do not give you any guarantees this will reach
> > 2.6.36, you have to ping dwmw2.
> 
> Any chance to get this in? The mxc-nand driver is nonfunctional at the
> moment and 2.6.36 is getting closer.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

(for the patch and the request to get it in before 2.6.36.)

Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

Re: [PATCH] mtd: mxc_nand: do not depend on disabling the irq in the interrupt handler

[Eric Bénard]

Hi David,

Le 23/09/2010 13:16, Artem Bityutskiy a écrit :
> On Tue, 2010-09-21 at 09:40 +0200, Sascha Hauer wrote:
>> This patch reverts the driver to enabling/disabling the NFC interrupt
>> mask rather than enabling/disabling the system interrupt. This cleans
>> up the driver so that it doesn't rely on interrupts being disabled
>> within the interrupt handler.
>> For i.MX21 we keep the current behaviour, that is calling
>> enable_irq/disable_irq_nosync to enable/disable interrupts.
>> This patch is based on earlier work by John Ogness.
>>
>> Signed-off-by: Sascha Hauer<s.hauer@pengutronix.de>
>> Acked-by: John Ogness<john.ogness@linutronix.de>
>> Tested-by: John Ogness<john.ogness@linutronix.de>
>
> I've created l2-mtd-2.6.git/for-2.6.36 branch, pushed your patch there,
> pinged dwmw2 for you. I do not give you any guarantees this will reach
> 2.6.36, you have to ping dwmw2.
>
Would that be possible to merge Artem's l2-mtd-2.6.git/for-2.6.36 branch for 
2.6.36 (or at least cherry-pick 34e15930f2c322389d4f946bf891601a2d1e4280 from 
this branch) ? Without it mxc-nand is broken in 2.6.36.

Many thanks
Eric