[U-Boot] [PATCH v1 1/4] arm, imx6: add mxc_iomux_set_gpr_register function

Heiko Schocher hs at denx.de
Fri Jul 11 15:00:04 CEST 2014


Hello Stefano,

Am 11.07.2014 13:10, schrieb Stefano Babic:
> Hi Heiko,
>
> On 28/05/2014 12:16, Heiko Schocher wrote:
>> add mxc_iomux_set_gpr_register fucntion
>>
>> Signed-off-by: Heiko Schocher<hs at denx.de>
>> Cc: Stefano Babic<sbabic at denx.de>
>> ---
>>   arch/arm/imx-common/iomux-v3.c             | 15 +++++++++++++++
>>   arch/arm/include/asm/imx-common/iomux-v3.h |  2 ++
>>   2 files changed, 17 insertions(+)
>>
>> diff --git a/arch/arm/imx-common/iomux-v3.c b/arch/arm/imx-common/iomux-v3.c
>> index 6e46ea8..8739b4c 100644
>> --- a/arch/arm/imx-common/iomux-v3.c
>> +++ b/arch/arm/imx-common/iomux-v3.c
>> @@ -63,3 +63,18 @@ void imx_iomux_v3_setup_multiple_pads(iomux_v3_cfg_t const *pad_list,
>>   	for (i = 0; i<  count; i++)
>>   		imx_iomux_v3_setup_pad(*p++);
>>   }
>> +
>> +void mxc_iomux_set_gpr_register(int group, int start_bit, int num_bits,
>> +				int value)
>> +{
>> +	int i = 0;
>> +	u32 reg;
>> +	reg = __raw_readl(base + group * 4);
>> +	while (num_bits) {
>> +		reg&= ~(1<<(start_bit + i));
>> +		i++;
>> +		num_bits--;
>> +	}
>> +	reg |= (value<<  start_bit);
>> +	__raw_writel(reg, base + group * 4);
>> +}
>
> It is not clear to me why we need to add this or better, I want to avoid
> having twice quite the same code doing the same ;-).
>
> We have already a field for gpr:
> struct iomuxc {
>          u32 gpr[14];
>          u32 omux[5];
>          /* mux and pad registers */
> };

Ah!

> +	reg = __raw_readl(base + group * 4);
>
> this could not work when Freescale introduce a new variant with a slight
> different layout. Thanks to Fabio, we know this is already reality:
>
> 	http://patchwork.ozlabs.org/patch/368336/
>
> Your code *does* not work with the solox.
>
> Generally, we access register and we use setbits_ and clrsetbits_ to
> modify single bits. What is the advantage here ?

None, patch not longer needed. I remove it from the next patchserie.

Thanks!

bye,
Heiko
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany


More information about the U-Boot mailing list