Re: [rtc-linux] [RESEND PATCH] RTC: MAX77686: Add Maxim 77686 driver

[jonghwa3.lee@samsung.com]

Hi, Andrew,
On 2012년 12월 19일 09:30, Andrew Morton wrote:
> On Wed, 28 Nov 2012 15:50:57 +0900
> Jonghwa Lee <jonghwa3.lee@samsung.com> wrote:
> 
>> Add driver for support max77686 rtc.
>> MAX77686 rtc support smpl and wtsr mode. It has two alarm register
>> which can be used for alarming to wake system up. This drvier uses regmap
>> to access its register.
>>
>> ...
>>
>> +static inline int max77686_rtc_calculate_wday(u8 shifted)
>> +{
>> +	int counter = -1;
>> +	while (shifted) {
>> +		shifted >>= 1;
>> +		counter++;
>> +	}
>> +	return counter;
>> +}
> 
> We should be able to use log2() in here?
> 
Okay, and I'd like to use Joe's recommendation. fls(shitfted) - 1

>>
>> ...
>>
>> +static inline int max77686_rtc_update(struct max77686_rtc_info *info,
>> +	enum MAX77686_RTC_OP op)
>> +{
>> +	int ret;
>> +	unsigned int data;
>> +
>> +	switch (op) {
>> +	case MAX77686_RTC_WRITE:
>> +		data = 1 << RTC_UDR_SHIFT;
>> +		break;
>> +	case MAX77686_RTC_READ:
>> +		data = 1 << RTC_RBUDR_SHIFT;
>> +		break;
>> +	}
>> +
>> +	ret = regmap_update_bits(info->max77686->rtc_regmap,
>> +				 MAX77686_RTC_UPDATE0, data, data);
>> +	if (ret < 0)
>> +		dev_err(info->dev, "%s: fail to write update reg(ret=%d, data=0x%x)\n",
>> +				__func__, ret, data);
>> +	else {
>> +		/* Minimum 16ms delay required before RTC update. */
>> +		msleep(MAX77686_RTC_UPDATE_DELAY);
>> +	}
>> +
>> +	return ret;
>> +}
> 
> This function has about ten callers.  No way in the world do we want it
> to be inlined!  Probably the compiler will just ignore your `inline',
> but we should remove it to be sure.
> 
Okay, I'll remove it.
>>
>> ...
>>
>> +static const struct rtc_class_ops max77686_rtc_ops = {
>> +	.read_time = max77686_rtc_read_time,
>> +	.set_time = max77686_rtc_set_time,
>> +	.read_alarm = max77686_rtc_read_alarm,
>> +	.set_alarm = max77686_rtc_set_alarm,
>> +	.alarm_irq_enable = max77686_rtc_alarm_irq_enable,
>> +};
>> +
>> +#ifdef MAX77686_RTC_WTSR_SMPL
> 
> hm, this is always undefined.  Why is this code here?
>
Yes, you're right, It isn't needed. I'll fix it right.

>> +static void max77686_rtc_enable_wtsr(struct max77686_rtc_info *info, bool enable)
>> +{
>> +	int ret;
>> +	unsigned int val, mask;
>> +
>> +	if (enable)
>> +		val = (1 << WTSR_EN_SHIFT) | (3 << WTSRT_SHIFT);
>> +	else
>> +		val = 0;
>> +
>> +	mask = WTSR_EN_MASK | WTSRT_MASK;
>> +
>> +	dev_info(info->dev, "%s: %s WTSR\n", __func__,
>> +			enable ? "enable" : "disable");
>> +
>> +	ret = regmap_update_bits(info->max77686->rtc_regmap,
>> +				 MAX77686_WTSR_SMPL_CNTL, mask, val);
>> +	if (ret < 0) {
>> +		dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n",
>> +				__func__, ret);
>> +		return;
>> +	}
>> +
>> +	max77686_rtc_update(info, MAX77686_RTC_WRITE);
>> +}
>> +
>> +static void max77686_rtc_enable_smpl(struct max77686_rtc_info *info, bool enable)
>> +{
>> +	int ret;
>> +	unsigned int val, mask;
>> +
>> +	if (enable)
>> +		val = (1 << SMPL_EN_SHIFT) | (0 << SMPLT_SHIFT);
>> +	else
>> +		val = 0;
>> +
>> +	mask = SMPL_EN_MASK | SMPLT_MASK;
>> +
>> +	dev_info(info->dev, "%s: %s SMPL\n", __func__,
>> +			enable ? "enable" : "disable");
>> +
>> +	ret = regmap_update_bits(info->max77686->rtc_regmap,
>> +				 MAX77686_WTSR_SMPL_CNTL, mask, val);
>> +	if (ret < 0) {
>> +		dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n",
>> +				__func__, ret);
>> +		return;
>> +	}
>> +
>> +	max77686_rtc_update(info, MAX77686_RTC_WRITE);
>> +
>> +	val = 0;
>> +	regmap_read(info->max77686->rtc_regmap, MAX77686_WTSR_SMPL_CNTL, &val);
>> +	pr_info("%s: WTSR_SMPL(0x%02x)\n", __func__, val);
>> +}
>> +#endif /* MAX77686_RTC_WTSR_SMPL */
>>
>> ...
>>
>> +static int __devinit max77686_rtc_probe(struct platform_device *pdev)
> 
> CONFIG_HOTPLUG is removed, so we should stop using devinit, devexit,
> devinit_p, etc.
> 
>>
>> ...
>>
> 
> --- a/drivers/rtc/rtc-max77686.c~rtc-max77686-add-maxim-77686-driver-fix
> +++ a/drivers/rtc/rtc-max77686.c
> @@ -129,7 +129,7 @@ static int max77686_rtc_tm_to_data(struc
>  	return 0;
>  }
>  
> -static inline int max77686_rtc_update(struct max77686_rtc_info *info,
> +static int max77686_rtc_update(struct max77686_rtc_info *info,
>  	enum MAX77686_RTC_OP op)
>  {
>  	int ret;
> @@ -501,7 +501,7 @@ static struct regmap_config max77686_rtc
>  	.val_bits = 8,
>  };
>  
> -static int __devinit max77686_rtc_probe(struct platform_device *pdev)
> +static int max77686_rtc_probe(struct platform_device *pdev)
>  {
>  	struct max77686_dev *max77686 = dev_get_drvdata(pdev->dev.parent);
>  	struct max77686_rtc_info *info;
> @@ -575,7 +575,7 @@ out:
>  	return ret;
>  }
>  
> -static int __devexit max77686_rtc_remove(struct platform_device *pdev)
> +static int max77686_rtc_remove(struct platform_device *pdev)
>  {
>  	struct max77686_rtc_info *info = platform_get_drvdata(pdev);
>  
> @@ -623,7 +623,7 @@ static struct platform_driver max77686_r
>  		.owner	= THIS_MODULE,
>  	},
>  	.probe		= max77686_rtc_probe,
> -	.remove		= __devexit_p(max77686_rtc_remove),
> +	.remove		= max77686_rtc_remove,
>  	.shutdown	= max77686_rtc_shutdown,
>  	.id_table	= rtc_id,
>  };
> _
> 
> 
Best regards
Jonghwa.