From: Guenter Roeck <linux@roeck-us.net>
To: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Cc: mazziesaccount@gmail.com, heikki.haikola@fi.rohmeurope.com,
mikko.mutanen@fi.rohmeurope.com, lee.jones@linaro.org,
robh+dt@kernel.org, mark.rutland@arm.com, broonie@kernel.org,
gregkh@linuxfoundation.org, rafael@kernel.org,
mturquette@baylibre.com, sboyd@kernel.org,
linus.walleij@linaro.org, bgolaszewski@baylibre.com,
sre@kernel.org, lgirdwood@gmail.com, a.zummo@towertech.it,
alexandre.belloni@bootlin.com, wim@linux-watchdog.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org,
linux-pm@vger.kernel.org, linux-rtc@vger.kernel.org,
linux-watchdog@vger.kernel.org
Subject: Re: [RFC PATCH v2 08/10] rtc: bd70528: Initial support for ROHM bd70528 RTC
Date: Mon, 28 Jan 2019 06:02:47 -0800 [thread overview]
Message-ID: <11ff93bf-c71f-7489-841f-09bf757a8ba7@roeck-us.net> (raw)
In-Reply-To: <20190128074849.GB2030@localhost.localdomain>
On 1/27/19 11:48 PM, Matti Vaittinen wrote:
> Thanks again Guenter,
>
> On Sat, Jan 26, 2019 at 08:30:24AM -0800, Guenter Roeck wrote:
>> On 1/25/19 3:05 AM, Matti Vaittinen wrote:
>>> +/*
>>> + * We read regs RTC_SEC => RTC_YEAR
>>> + * this struct is ordered according to chip registers.
>>> + * Keep it u8 only to avoid padding issues.
>>> + */
>>> +struct bd70528_rtc_day {
>>> + u8 sec;
>>> + u8 min;
>>> + u8 hour;
>>> +};
>>> +
>>> +struct bd70528_rtc_data {
>>> + struct bd70528_rtc_day time;
>>> + u8 week;
>>> + u8 day;
>>> + u8 month;
>>> + u8 year;
>>> +};
>>> +
>>> +struct bd70528_rtc_wake {
>>> + struct bd70528_rtc_day time;
>>> + u8 ctrl;
>>> +};
>>> +
>>> +struct bd70528_rtc_alm {
>>> + struct bd70528_rtc_data data;
>>> + u8 alm_mask;
>>> + u8 alm_repeat;
>>> +};
>>
>> At least some of the above are directly associated with chip registers.
>> I don't think this will work for all architectures without explicit packed
>> attribute.
>
> Allright. I was thinking of that but thought that most of the
> architectures using this PMIC would handle alignments fine if I used
> only u8 members. I did consider using __attribute__((packed)) - but I'm
> not sure if we hit into troubles with that too. I guess some people
> would like to compile kernel with other compiler(s) but gcc - although
> I'm not sure if this should be taken into account. I'll try doing some
> study on this - unless someone replies to this and just tells how this
> should be done. (I am pretty sure I can find the answer from mail
> archives though). I'll try adding some packing hint for compiler at v3.
>
Use __packed ?
>>> + if ((!enable) == (!(*old_state & BD70528_WAKE_STATE_BIT)))
>>> + return 0;
>>
>> I think
>> if (enable == !!(*old_state & BD70528_WAKE_STATE_BIT))
>> would be much better readable. Even if not, there are way too many ()
>> in the above conditional.
>
> Allright. I'll fix this
>
>>> + if (alm.alm_mask & BD70528_MASK_ALM_EN)
>>> + a->enabled = 0;
>>> + else
>>> + a->enabled = 1;
>>> +
>> Without conditional:
>> a->enabled = !(alm.alm_mask & BD70528_MASK_ALM_EN);
>>
>
> Right. Much nicer, thanks! I'll change this.
>
>>> +static int bd70528_set_time(struct device *dev, struct rtc_time *t)
>>> +{
>>> + int ret, old_states;
>>> + struct bd70528_rtc_data rtc_data;
>>> + struct bd70528_rtc *r = dev_get_drvdata(dev);
>>> + struct bd70528 *bd70528 = r->mfd;
>>> +
>>> + ret = bd70528_disable_rtc_based_timers(r, &old_states);
>>> +
>>
>> AFAICS the disable/enable functions are only called once. Since they
>> also apply set / clear a mutex, I find that a bit confusing. I think
>> it would be better to fold the code into this function. If anything,
>> I could imagine something like
>>
>> mutex_lock();
>> ret = bd70528_set_time_locked();
>> mutex_unlock()
>>
>> to simplify error handling.
>
> Yep. Makes sense. I'll tidy this.
>
>>> + ret = regmap_bulk_read(bd70528->chip.regmap,
>>> + BD70528_REG_RTC_START, &rtc_data,
>>> + sizeof(rtc_data));
>>> +
>>> + tm2rtc(t, &rtc_data);
>>> +
>>> + ret = regmap_bulk_write(bd70528->chip.regmap,
>>> + BD70528_REG_RTC_START, &rtc_data,
>>> + sizeof(rtc_data));
>>> +
>>> + ret = bd70528_re_enable_rtc_based_timers(r, old_states);
>>> +
>>
>> Kind of off that all the error returns are ignored here.
>
> And I'll fix this too.
>
> Br,
> Matti Vaittinen
>
next prev parent reply other threads:[~2019-01-28 14:02 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-25 11:05 [RFC PATCH v2 08/10] rtc: bd70528: Initial support for ROHM bd70528 RTC Matti Vaittinen
2019-01-26 16:30 ` Guenter Roeck
2019-01-28 7:48 ` Matti Vaittinen
2019-01-28 14:02 ` Guenter Roeck [this message]
2019-01-28 16:16 ` Matti Vaittinen
2019-01-28 20:26 ` Jerry Hoemann
2019-01-29 7:01 ` Matti Vaittinen
2019-01-30 0:24 ` Jerry Hoemann
2019-01-28 21:20 ` Alexandre Belloni
2019-01-29 11:46 ` Matti Vaittinen
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