Subject: [Linux-kernel] [PATCH 12/13] mmc: atmel-mci: use endian agnostic IO

From: [email-masked] (Ben Dooks)
Date: Tue, 24 Mar 2015 12:53:41 +0000

On 19/03/15 14:22, Ben Hutchings wrote:
> On Wed, 2015-03-18 at 15:53 +0000, Ben Dooks wrote:
>> Change the __raw IO functions to endian agnostic relaxed ones to allow
>> the driver to function on big endian ARM systems.
>>
>> Signed-off-by: Ben Dooks <[email-masked]>
>> --
>> CC: Ludovic Desroches <[email-masked]>
>> CC: Chris Ball <[email-masked]>
>> CC: Ulf Hansson <[email-masked]>
>> CC: linux-mmc at vger.kernel.org
>> ---
>>  drivers/mmc/host/atmel-mci-regs.h | 9 ++++++++-
>>  1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h
>> index c97001e..711bb53 100644
>> --- a/drivers/mmc/host/atmel-mci-regs.h
>> +++ b/drivers/mmc/host/atmel-mci-regs.h
>> @@ -135,10 +135,17 @@
>>  #define ATMCI_REGS_SIZE		0x100
>>  
>>  /* Register access macros */
>> -#define atmci_readl(port,reg)				\
>> +#ifdef CONFIG_AVR32
>> +#define atmci_readl(port,reg)			\
>>  	__raw_readl((port)->regs + reg)
>>  #define atmci_writel(port,reg,value)			\
>>  	__raw_writel((value), (port)->regs + reg)
>> +#else
>> +#define atmci_readl(port,reg)			\
>> +	readl_relaxed((port)->regs + reg)
>> +#define atmci_writel(port,reg,value)			\
>> +	writel_relaxed((value), (port)->regs + reg)
>> +#endif
> 
> This pattern is repeated in a lot of drivers; is it worth defining
> atmel_{read,write}l_relaxed() in a common header?
> 
> #ifdef CONFIG_AVR32
> 
> /* CPU and peripherals are both big-endian, so don't byte-swap */
> #define atmel_readl_relaxed(addr)		__raw_readl(addr)
> #define atmel_writel_relaxed(value, addr)	__raw_writel(value, addr)
> 
> #else
> 
> /* Peripherals are little-endian, so byte-swap if CPU isn't */
> #define atmel_readl_relaxed(addr)		readl_relaxed(addr)
> #define atmel_writel_relaxed(value, addr)	writel_relaxed(value, addr)
> 
> #endif
> 
> Ben.

Hi, I think it will probably be a good idea to have an avr32/at91
read/write functions however I will put this forward as a separate
series as it will require both avr32 and at91 maintainers as well
as driver updates.

how about:
	atmel_readl_onchip{b,w,l}
	atmel_writel_onchip{b,w,l}

-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius