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

[Guenter Roeck <linux@roeck-us.net>]

On 03/30/2014 09:18 PM, Li.Xiubo@freescale.com 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@freescale.com>
>>> Cc: Guenter Roeck <linux@roeck-us.net>
>>
>> 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
>
>
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>
>
>> 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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