linux-kernel - Re: [PATCH v4 4/7] soc: mediatek: pwrap: update pwrap

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Date:   Fri, 13 Oct 2017 16:07:57 +0200
From:   Matthias Brugger <matthias.bgg@...il.com>
To:     Sean Wang <sean.wang@...iatek.com>
Cc:     robh+dt@...nel.org, mark.rutland@....com,
        devicetree@...r.kernel.org, linux-mediatek@...ts.infradead.org,
        chen.zhong@...iatek.com, chenglin.xu@...iatek.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 4/7] soc: mediatek: pwrap: update pwrap_init without
 slave programming



On 10/13/2017 11:41 AM, Sean Wang wrote:
> On Tue, 2017-10-10 at 20:00 +0200, Matthias Brugger wrote:
>>
>> On 09/21/2017 10:26 AM, sean.wang@...iatek.com wrote:
>>> From: Sean Wang <sean.wang@...iatek.com>
>>>
>>> pwrap initialization is highly associated with the base SoC, so
>>> update here for allowing pwrap_init without slave program which would be
>>> used to those PMICs without extra encryption on bus such as MT6380.
>>>
>>> Signed-off-by: Chenglin Xu <chenglin.xu@...iatek.com>
>>> Signed-off-by: Chen Zhong <chen.zhong@...iatek.com>
>>> Signed-off-by: Sean Wang <sean.wang@...iatek.com>
>>> ---
>>>    drivers/soc/mediatek/mtk-pmic-wrap.c | 91 +++++++++++++++++++++---------------
>>>    1 file changed, 54 insertions(+), 37 deletions(-)
>>>
>>> diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
>>> index 27d7ccc..9c6d855 100644
>>> --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
>>> +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
>>> @@ -531,6 +531,7 @@ struct pmic_wrapper_type {
>>>    	u32 spi_w;
>>>    	u32 wdt_src;
>>>    	int has_bridge:1;
>>> +	int slv_program:1;
>>>    	int (*init_reg_clock)(struct pmic_wrapper *wrp);
>>>    	int (*init_soc_specific)(struct pmic_wrapper *wrp);
>>>    };
>>> @@ -999,9 +1000,12 @@ static int pwrap_init(struct pmic_wrapper *wrp)
>>>    	}
>>>    
>>>    	/* Reset SPI slave */
>>> -	ret = pwrap_reset_spislave(wrp);
>>> -	if (ret)
>>> -		return ret;
>>> +
>>> +	if (wrp->master->slv_program) {
>>> +		ret = pwrap_reset_spislave(wrp);
>>> +		if (ret)
>>> +			return ret;
>>> +	}
>>>    
>>>    	pwrap_writel(wrp, 1, PWRAP_WRAP_EN);
>>>    
>>> @@ -1013,45 +1017,52 @@ static int pwrap_init(struct pmic_wrapper *wrp)
>>>    	if (ret)
>>>    		return ret;
>>>    
>>> -	/* Setup serial input delay */
>>> -	ret = pwrap_init_sidly(wrp);
>>> -	if (ret)
>>> -		return ret;
>>> +	if (wrp->master->slv_program) {
>>
>> This if branch is really long and complex enough to put it into function apart.
>>
>> Thanks,
>> Matthias
>>
>> PD please take into account the comments I made on v3 of the series.
>>
> 
> I'll try to breakdown the long logic into the short one and use a flag
> indicating the slave capability decides whether the functions is
> required being enabled for the slave instead of slv_program which is
> less meaningful. In this way, pmic_init will be more extensible when
> more different SoCs and target slaves with various flavors into the
> driver. And also take into accounts those suggestions you made in v3 in
> the next version.
> 
> 	Sean
> 

I totally agree, but I wanted to underline that right now the if branch under
"if (wrp->master->slv_program)" is around 30 lines, so I think it would be a 
good candidate to put it into it's own function. For example: 
pwrap_init_encryption()
As from what I understand from the commit log, slv_program in the end enables 
encryption of the communication, right?

Regards,
Matthias