From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
To: Javier Martinez Canillas <javier@osg.samsung.com>,
linux-kernel@vger.kernel.org
Cc: Kukjin Kim <kgene@kernel.org>,
rtc-linux@googlegroups.com, Chanwoo Choi <cw00.choi@samsung.com>,
Alexandre Belloni <alexandre.belloni@free-electrons.com>,
Laxman Dewangan <ldewangan@nvidia.com>,
linux-samsung-soc@vger.kernel.org
Subject: Re: [PATCH 3/8] rtc: max77686: Use a driver data struct instead hard-coded values
Date: Thu, 21 Jan 2016 09:45:25 +0900 [thread overview]
Message-ID: <56A02A25.9050905@samsung.com> (raw)
In-Reply-To: <1453310088-29985-4-git-send-email-javier@osg.samsung.com>
On 21.01.2016 02:14, Javier Martinez Canillas wrote:
> The driver has some hard-coded values such as the minimum delay needed
> before a RTC update or the mask used for the sec/min/hour/etc registers.
>
> Use a data structure that contains these values and pass as driver data
> using the platform device ID table for each device.
>
> This allows to make the driver's ops callbacks more generic so other RTC
> that are similar but don't have the same values can also be supported.
>
> Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
> ---
>
> drivers/rtc/rtc-max77686.c | 47 +++++++++++++++++++++++++++++-----------------
> 1 file changed, 30 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c
> index ae4d61e7ce4b..441d163dcbeb 100644
> --- a/drivers/rtc/rtc-max77686.c
> +++ b/drivers/rtc/rtc-max77686.c
> @@ -41,8 +41,6 @@
> #define ALARM_ENABLE_SHIFT 7
> #define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)
>
> -#define MAX77686_RTC_UPDATE_DELAY 16000
> -
> enum {
> RTC_SEC = 0,
> RTC_MIN,
> @@ -54,6 +52,11 @@ enum {
> RTC_NR_TIME
> };
>
> +struct rtc_driver_data {
1. This is only local structure so maybe: max77686_rtc_driver_data?
2. Can you put here a comment explaining the purpose of this delay
(quite generic name) and used units?
> + unsigned long delay;
A comment here - what 'mask'? Generic name so explanation would be welcomed.
> + int mask;
I think this should be u8 to avoid early promotions to int. It is used
directly with other u8 values. At the end effect of operation is
promoted to int anyway but using only u8 for operations looks more
consistent to me.
> +};
> +
> struct max77686_rtc_info {
> struct device *dev;
> struct max77686_dev *max77686;
> @@ -63,6 +66,8 @@ struct max77686_rtc_info {
>
> struct regmap *regmap;
>
> + struct rtc_driver_data *drv_data;
That may be pointer to const data. Actually not "may be" but
even "should be" because you allocate later really a const data and you
are discarding const-ness with cast.
> +
> int virq;
> int rtc_24hr_mode;
> };
> @@ -72,12 +77,19 @@ enum MAX77686_RTC_OP {
> MAX77686_RTC_READ,
> };
>
> +static const struct rtc_driver_data max77686_drv_data = {
> + .delay = 1600,
> + .mask = 0x7f,
> +};
> +
> static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
> - int rtc_24hr_mode)
> + struct max77686_rtc_info *info)
> {
> - tm->tm_sec = data[RTC_SEC] & 0x7f;
> - tm->tm_min = data[RTC_MIN] & 0x7f;
> - if (rtc_24hr_mode)
> + int mask = info->drv_data->mask;
> +
> + tm->tm_sec = data[RTC_SEC] & mask;
> + tm->tm_min = data[RTC_MIN] & mask;
> + if (info->rtc_24hr_mode)
> tm->tm_hour = data[RTC_HOUR] & 0x1f;
> else {
> tm->tm_hour = data[RTC_HOUR] & 0x0f;
> @@ -86,10 +98,10 @@ static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
> }
>
> /* Only a single bit is set in data[], so fls() would be equivalent */
> - tm->tm_wday = ffs(data[RTC_WEEKDAY] & 0x7f) - 1;
> + tm->tm_wday = ffs(data[RTC_WEEKDAY] & mask) - 1;
> tm->tm_mday = data[RTC_DATE] & 0x1f;
> tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
> - tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100;
> + tm->tm_year = (data[RTC_YEAR] & mask) + 100;
> tm->tm_yday = 0;
> tm->tm_isdst = 0;
> }
> @@ -117,6 +129,7 @@ static int max77686_rtc_update(struct max77686_rtc_info *info,
> {
> int ret;
> unsigned int data;
> + unsigned long delay = info->drv_data->delay;
>
> if (op == MAX77686_RTC_WRITE)
> data = 1 << RTC_UDR_SHIFT;
> @@ -129,9 +142,8 @@ static int max77686_rtc_update(struct max77686_rtc_info *info,
> 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. */
> - usleep_range(MAX77686_RTC_UPDATE_DELAY,
> - MAX77686_RTC_UPDATE_DELAY * 2);
> + /* Minimum delay required before RTC update. */
> + usleep_range(delay, delay * 2);
> }
>
> return ret;
> @@ -156,7 +168,7 @@ static int max77686_rtc_read_time(struct device *dev, struct rtc_time *tm)
> goto out;
> }
>
> - max77686_rtc_data_to_tm(data, tm, info->rtc_24hr_mode);
> + max77686_rtc_data_to_tm(data, tm, info);
>
> ret = rtc_valid_tm(tm);
>
> @@ -213,7 +225,7 @@ static int max77686_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> goto out;
> }
>
> - max77686_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode);
> + max77686_rtc_data_to_tm(data, &alrm->time, info);
>
> alrm->enabled = 0;
> for (i = 0; i < RTC_NR_TIME; i++) {
> @@ -260,7 +272,7 @@ static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
> goto out;
> }
>
> - max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);
> + max77686_rtc_data_to_tm(data, &tm, info);
>
> for (i = 0; i < RTC_NR_TIME; i++)
> data[i] &= ~ALARM_ENABLE_MASK;
> @@ -299,7 +311,7 @@ static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
> goto out;
> }
>
> - max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);
> + max77686_rtc_data_to_tm(data, &tm, info);
>
> data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT);
> data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT);
> @@ -307,7 +319,7 @@ static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
> data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
> if (data[RTC_MONTH] & 0xf)
> data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT);
> - if (data[RTC_YEAR] & 0x7f)
> + if (data[RTC_YEAR] & info->drv_data->mask)
> data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
> if (data[RTC_DATE] & 0x1f)
> data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT);
> @@ -436,6 +448,7 @@ static int max77686_rtc_probe(struct platform_device *pdev)
> info->dev = &pdev->dev;
> info->max77686 = max77686;
> info->rtc = max77686->rtc;
> + info->drv_data = (struct rtc_driver_data *)pdev->id_entry->driver_data;
That cast dropping constness is bad.
Best regards,
Krzysztof
>
> platform_set_drvdata(pdev, info);
>
> @@ -510,7 +523,7 @@ static SIMPLE_DEV_PM_OPS(max77686_rtc_pm_ops,
> max77686_rtc_suspend, max77686_rtc_resume);
>
> static const struct platform_device_id rtc_id[] = {
> - { "max77686-rtc", 0 },
> + { "max77686-rtc", .driver_data = (kernel_ulong_t)&max77686_drv_data, },
> {},
> };
> MODULE_DEVICE_TABLE(platform, rtc_id);
>
next prev parent reply other threads:[~2016-01-21 1:00 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-20 17:14 [PATCH 0/8] rtc: max77686: Extend driver and add max77802 support Javier Martinez Canillas
2016-01-20 17:14 ` [PATCH 1/8] rtc: max77686: Use ARRAY_SIZE() instead of current array length Javier Martinez Canillas
2016-01-21 0:35 ` Krzysztof Kozlowski
2016-01-20 17:14 ` [PATCH 2/8] rtc: max77686: Use usleep_range() instead of msleep() Javier Martinez Canillas
2016-01-21 0:37 ` Krzysztof Kozlowski
2016-01-21 14:52 ` Javier Martinez Canillas
2016-01-20 17:14 ` [PATCH 3/8] rtc: max77686: Use a driver data struct instead hard-coded values Javier Martinez Canillas
2016-01-21 0:45 ` Krzysztof Kozlowski [this message]
2016-01-21 14:55 ` Javier Martinez Canillas
2016-01-20 17:14 ` [PATCH 4/8] rtc: max77686: Add an indirection level to access RTC registers Javier Martinez Canillas
2016-01-21 1:05 ` Krzysztof Kozlowski
2016-01-21 14:57 ` Javier Martinez Canillas
2016-01-20 17:14 ` [PATCH 5/8] rtc: max77686: Add max77802 support Javier Martinez Canillas
2016-01-21 1:56 ` Krzysztof Kozlowski
2016-01-21 15:12 ` Javier Martinez Canillas
2016-01-20 17:14 ` [PATCH 6/8] rtc: Remove Maxim 77802 driver Javier Martinez Canillas
2016-01-21 1:57 ` Krzysztof Kozlowski
2016-01-21 15:12 ` Javier Martinez Canillas
2016-01-20 17:14 ` [PATCH 7/8] ARM: exynos_defconfig: Remove MAX77802 RTC Kconfig symbol Javier Martinez Canillas
2016-01-21 1:58 ` Krzysztof Kozlowski
2016-01-21 15:14 ` Javier Martinez Canillas
2016-01-20 17:14 ` [PATCH 8/8] ARM: multi_v7_defconfig: " Javier Martinez Canillas
2016-01-21 1:58 ` Krzysztof Kozlowski
2016-01-21 0:30 ` [PATCH 0/8] rtc: max77686: Extend driver and add max77802 support Alexandre Belloni
2016-01-21 0:34 ` Krzysztof Kozlowski
2016-01-21 14:50 ` Javier Martinez Canillas
2016-01-21 0:48 ` Krzysztof Kozlowski
2016-01-21 15:15 ` Javier Martinez Canillas
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