Re: [PATCHv2 2/2] watchdog: imx2_wdt: Add big-endian support

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On 03/30/2014 09:18 PM, Li.Xiubo@xxxxxxxxxxxxx wrote:


Subject: Re: [PATCHv2 2/2] watchdog: imx2_wdt: Add big-endian support

On 03/25/2014 07:21 PM, Xiubo Li wrote:
For the platforms that this IP driver now supports:
SoC        CPU        Watchdog     Need 'big-endian'?
------------------------------------------------------
Vybird     little     little       No
LS1        little     big          Yes
LS2        little     little       No
IMX+       little     little       No

So for the LS1 SoCs, we need to do the big endianness converting.

And this will also support the following case, for example:
SoC        CPU        Watchdog     Need 'big-endian'?
------------------------------------------------------
PowerPC    big        big          Yes

Signed-off-by: Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>

Is this patch intended to solve the problem generically ?

http://www.spinics.net/lists/kernel/msg1714375.html


It's actually the following ones first, which will support 16-bits
Values for regmap-mmio:

https://patchwork.kernel.org/patch/3896321/
https://patchwork.kernel.org/patch/3896331/
https://patchwork.kernel.org/patch/3901021/

And the then the following one, which will support the LE endian:
http://www.spinics.net/lists/kernel/msg1714375.html

So what is the plan for this patch ? Seems to me it would make more sense
to convert the driver to regmap.

Guenter


Thanks :)

BRs
Xiubo





Guenter

---
   drivers/watchdog/imx2_wdt.c | 40 +++++++++++++++++++++++++++++++---------
   1 file changed, 31 insertions(+), 9 deletions(-)

diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 1795922..32f8874 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -30,6 +30,7 @@
   #include <linux/miscdevice.h>
   #include <linux/module.h>
   #include <linux/moduleparam.h>
+#include <linux/of.h>
   #include <linux/platform_device.h>
   #include <linux/timer.h>
   #include <linux/uaccess.h>
@@ -64,9 +65,26 @@ static struct {
   	void __iomem *base;
   	unsigned timeout;
   	unsigned long status;
+	bool big_endian;
   	struct timer_list timer;	/* Pings the watchdog when closed */
   } imx2_wdt;

+static inline u16 imx2_wdt_readw(void __iomem *addr)
+{
+	if (imx2_wdt.big_endian)
+		return ioread16be(addr);
+	else
+		return ioread16(addr);
+}
+
+static inline void imx2_wdt_writew(u16 val, void __iomem *addr)
+{
+	if (imx2_wdt.big_endian)
+		iowrite16be(val, addr);
+	else
+		iowrite16(val, addr);
+}
+
   static struct miscdevice imx2_wdt_miscdev;

   static bool nowayout = WATCHDOG_NOWAYOUT;
@@ -87,7 +105,7 @@ static const struct watchdog_info imx2_wdt_info = {

   static inline void imx2_wdt_setup(void)
   {
-	u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);
+	u16 val = imx2_wdt_readw(imx2_wdt.base + IMX2_WDT_WCR);

   	/* Suspend timer in low power mode, write once-only */
   	val |= IMX2_WDT_WCR_WDZST;
@@ -100,17 +118,17 @@ static inline void imx2_wdt_setup(void)
   	/* Set the watchdog's Time-Out value */
   	val |= WDOG_SEC_TO_COUNT(imx2_wdt.timeout);

-	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
+	imx2_wdt_writew(val, imx2_wdt.base + IMX2_WDT_WCR);

   	/* enable the watchdog */
   	val |= IMX2_WDT_WCR_WDE;
-	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
+	imx2_wdt_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
   }

   static inline void imx2_wdt_ping(void)
   {
-	__raw_writew(IMX2_WDT_SEQ1, imx2_wdt.base + IMX2_WDT_WSR);
-	__raw_writew(IMX2_WDT_SEQ2, imx2_wdt.base + IMX2_WDT_WSR);
+	imx2_wdt_writew(IMX2_WDT_SEQ1, imx2_wdt.base + IMX2_WDT_WSR);
+	imx2_wdt_writew(IMX2_WDT_SEQ2, imx2_wdt.base + IMX2_WDT_WSR);
   }

   static void imx2_wdt_timer_ping(unsigned long arg)
@@ -143,12 +161,12 @@ static void imx2_wdt_stop(void)

   static void imx2_wdt_set_timeout(int new_timeout)
   {
-	u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);
+	u16 val = imx2_wdt_readw(imx2_wdt.base + IMX2_WDT_WCR);

   	/* set the new timeout value in the WSR */
   	val &= ~IMX2_WDT_WCR_WT;
   	val |= WDOG_SEC_TO_COUNT(new_timeout);
-	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
+	imx2_wdt_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
   }

   static int imx2_wdt_open(struct inode *inode, struct file *file)
@@ -192,7 +210,7 @@ static long imx2_wdt_ioctl(struct file *file, unsigned
int cmd,
   		return put_user(0, p);

   	case WDIOC_GETBOOTSTATUS:
-		val = __raw_readw(imx2_wdt.base + IMX2_WDT_WRSR);
+		val = imx2_wdt_readw(imx2_wdt.base + IMX2_WDT_WRSR);
   		new_value = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
   		return put_user(new_value, p);

@@ -257,8 +275,12 @@ static struct miscdevice imx2_wdt_miscdev = {

   static int __init imx2_wdt_probe(struct platform_device *pdev)
   {
-	int ret;
+	struct device_node *np = pdev->dev.of_node;
   	struct resource *res;
+	int ret;
+
+	if (np)
+		imx2_wdt.big_endian = of_property_read_bool(np, "big-endian");

   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
   	imx2_wdt.base = devm_ioremap_resource(&pdev->dev, res);







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