linux-kernel - Re: [PATCH] clocksource: Ingenic: Improve the code.

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Date:   Sat, 24 Jul 2021 23:38:31 +0800
From:   Zhou Yanjie <zhouyanjie@...yeetech.com>
To:     Paul Cercueil <paul@...pouillou.net>
Cc:     daniel.lezcano@...aro.org, tglx@...utronix.de,
        linux-mips@...r.kernel.org, linux-kernel@...r.kernel.org,
        dongsheng.qiu@...enic.com, aric.pzqi@...enic.com,
        rick.tyliu@...enic.com, sihui.liu@...enic.com,
        jun.jiang@...enic.com, sernia.zhou@...mail.com
Subject: Re: [PATCH] clocksource: Ingenic: Improve the code.

Hi Paul,

On 2021/7/24 下午7:54, Paul Cercueil wrote:
> Hi Zhou,
>
> Thanks! I actually had a similar patch locally that I was eventually 
> going to send.
>
>
> Le sam., juil. 24 2021 at 18:10:07 +0800, 周琰杰 (Zhou Yanjie) 
> <zhouyanjie@...yeetech.com> a écrit :
>> Use "FIELD_GET()" and "FIELD_PREP()" to simplify the code.
>>
>> Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@...yeetech.com>
>> ---
>>  drivers/clocksource/ingenic-sysost.c | 11 +++++------
>>  1 file changed, 5 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/clocksource/ingenic-sysost.c 
>> b/drivers/clocksource/ingenic-sysost.c
>> index a129840..1fbea59 100644
>> --- a/drivers/clocksource/ingenic-sysost.c
>> +++ b/drivers/clocksource/ingenic-sysost.c
>> @@ -4,6 +4,7 @@
>>   * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@...yeetech.com>
>>   */
>>
>> +#include <linux/bitfield.h>
>>  #include <linux/bitops.h>
>>  #include <linux/clk.h>
>>  #include <linux/clk-provider.h>
>> @@ -34,8 +35,6 @@
>>  /* bits within the OSTCCR register */
>>  #define OSTCCR_PRESCALE1_MASK    0x3
>>  #define OSTCCR_PRESCALE2_MASK    0xc
>> -#define OSTCCR_PRESCALE1_LSB    0
>> -#define OSTCCR_PRESCALE2_LSB    2
>>
>>  /* bits within the OSTCR register */
>>  #define OSTCR_OST1CLR            BIT(0)
>> @@ -98,7 +97,7 @@ static unsigned long 
>> ingenic_ost_percpu_timer_recalc_rate(struct clk_hw *hw,
>>
>>      prescale = readl(ost_clk->ost->base + info->ostccr_reg);
>>
>> -    prescale = (prescale & OSTCCR_PRESCALE1_MASK) >> 
>> OSTCCR_PRESCALE1_LSB;
>> +    prescale = FIELD_GET(OSTCCR_PRESCALE1_MASK, prescale);
>>
>>      return parent_rate >> (prescale * 2);
>>  }
>> @@ -112,7 +111,7 @@ static unsigned long 
>> ingenic_ost_global_timer_recalc_rate(struct clk_hw *hw,
>>
>>      prescale = readl(ost_clk->ost->base + info->ostccr_reg);
>>
>> -    prescale = (prescale & OSTCCR_PRESCALE2_MASK) >> 
>> OSTCCR_PRESCALE2_LSB;
>> +    prescale = FIELD_GET(OSTCCR_PRESCALE2_MASK, prescale);
>>
>>      return parent_rate >> (prescale * 2);
>>  }
>> @@ -151,7 +150,7 @@ static int 
>> ingenic_ost_percpu_timer_set_rate(struct clk_hw *hw, unsigned long re
>>      int val;
>>
>>      val = readl(ost_clk->ost->base + info->ostccr_reg);
>> -    val = (val & ~OSTCCR_PRESCALE1_MASK) | (prescale << 
>> OSTCCR_PRESCALE1_LSB);
>> +    val = (val & ~OSTCCR_PRESCALE1_MASK) | 
>> FIELD_PREP(OSTCCR_PRESCALE1_MASK, prescale);
>
> Just one nitpick, I'd prefer this:
>
> val ~= &OSTCCR_PRESCALE1_MASK;
> val |= FIELD_PREP(OSTCCR_PRESCALE1_MASK, prescale);


Sure, I will change it in the next version.


>
>>      writel(val, ost_clk->ost->base + info->ostccr_reg);
>>
>>      return 0;
>> @@ -166,7 +165,7 @@ static int 
>> ingenic_ost_global_timer_set_rate(struct clk_hw *hw, unsigned long re
>>      int val;
>>
>>      val = readl(ost_clk->ost->base + info->ostccr_reg);
>> -    val = (val & ~OSTCCR_PRESCALE2_MASK) | (prescale << 
>> OSTCCR_PRESCALE2_LSB);
>> +    val = (val & ~OSTCCR_PRESCALE2_MASK) | 
>> FIELD_PREP(OSTCCR_PRESCALE2_MASK, prescale);
>
> Same here.


Sure.


Thanks and  best regards!


>
> Cheers,
> -Paul
>
>>      writel(val, ost_clk->ost->base + info->ostccr_reg);
>>
>>      return 0;
>> -- 
>> 2.7.4
>>
>