[PATCH 1/5] rtc: sun6i: Add sun6i RTC driver

Maxime Ripard maxime.ripard at free-electrons.com
Wed Jul 23 02:55:43 PDT 2014


Hi,

On Mon, Jul 21, 2014 at 10:46:06PM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Fri, Jul 18, 2014 at 4:07 PM, Maxime Ripard
> <maxime.ripard at free-electrons.com> wrote:
> > Hi,
> >
> > On Mon, Jul 14, 2014 at 03:32:13PM +0800, Chen-Yu Tsai wrote:
> >> This patch introduces the driver for the RTC in the Allwinner A31 and
> >> A23 SoCs.
> >>
> >> Unlike the RTC found in A10/A20 SoCs, which was part of the timer, the
> >> RTC in A31/A23 are a separate hardware block, which also contain a few
> >> controls for the RTC block hardware (a regulator and RTC block GPIO pin
> >> latches), while also having separate interrupts for the alarms.
> >
> > Do you plan on supporting those at some point?
> 
> I haven't seen any devices use the regulator (which has an output pin).
> I suppose we shouldn't add drivers for things we can't verify.
> As for the GPIO pin latches, I'll have to experiment some more to figure
> out what they do exactly.

Ok.

> > It's also worth noting that the first registers are supposed to
> > control the source of the low frequency oscillator in the SoC, which
> > will probably be the most troublesome, since we need these clocks very
> > early on.
> 
> That's true. I suppose the bootloader configures this. IIRC I've seen
> code for this in boot0 or boot1 from Allwinner. I can't find the equivalent
> for our sun4i u-boot though.

Do you know what was the bootloader configuring it to?

I don't really know how we can deal with this in a nice way, but I
guess it's not so urgent.

> >>
> >> The hardware is different enough to make a different driver for it.
> >>
> >> Signed-off-by: Chen-Yu Tsai <wens at csie.org>
> >> ---
> >>  .../devicetree/bindings/rtc/sun6i-rtc.txt          |  17 +
> >>  drivers/rtc/Kconfig                                |   7 +
> >>  drivers/rtc/Makefile                               |   1 +
> >>  drivers/rtc/rtc-sun6i.c                            | 466 +++++++++++++++++++++
> >>  4 files changed, 491 insertions(+)
> >>  create mode 100644 Documentation/devicetree/bindings/rtc/sun6i-rtc.txt
> >>  create mode 100644 drivers/rtc/rtc-sun6i.c
> >>
> >> diff --git a/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt b/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt
> >> new file mode 100644
> >> index 0000000..b18927c
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt
> >> @@ -0,0 +1,17 @@
> >> +* sun6i Real Time Clock
> >> +
> >> +RTC controller for the Allwinner A31
> >> +
> >> +Required properties:
> >> +- compatible : Should be "allwinner,sun6i-a31-rtc"
> >> +- reg: physical base address of the controller and length of memory mapped
> >> +  region.
> >> +- interrupts: IRQ line for the RTC alarm 0.
> >> +
> >> +Example:
> >> +
> >> +rtc: rtc at 01f00000 {
> >> +     compatible = "allwinner,sun6i-a31-rtc";
> >> +     reg = <0x01f00000 0x54>;
> >> +     interrupts = <0 40 4>;
> >> +};
> >> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> >> index 0754f5c..5b3910a 100644
> >> --- a/drivers/rtc/Kconfig
> >> +++ b/drivers/rtc/Kconfig
> >> @@ -1167,6 +1167,13 @@ config RTC_DRV_SUN4V
> >>         If you say Y here you will get support for the Hypervisor
> >>         based RTC on SUN4V systems.
> >>
> >> +config RTC_DRV_SUN6I
> >> +     tristate "Allwinner sun6i/sun8i RTC"
> >
> > I'm half convinced about an exhaustive list here. That IP will also
> > probably be used by sun9i, and sun10i if it ever exists, etc. And you
> > exhaustive list won't be anymore.
> >
> > I'd rather just mention the A31, like we do for the DT.
> 
> Fixed.
> 
> >> +     depends on MACH_SUN6I || MACH_SUN8I
> >> +     help
> >> +       If you say Y here you will get support for the RTC found on
> >> +       Allwinner A31/A23.
> >> +
> >>  config RTC_DRV_SUNXI
> >>       tristate "Allwinner sun4i/sun7i RTC"
> >>       depends on ARCH_SUNXI
> >> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> >> index 70347d0..a47df29 100644
> >> --- a/drivers/rtc/Makefile
> >> +++ b/drivers/rtc/Makefile
> >> @@ -123,6 +123,7 @@ obj-$(CONFIG_RTC_DRV_STARFIRE)    += rtc-starfire.o
> >>  obj-$(CONFIG_RTC_DRV_STK17TA8)       += rtc-stk17ta8.o
> >>  obj-$(CONFIG_RTC_DRV_STMP)   += rtc-stmp3xxx.o
> >>  obj-$(CONFIG_RTC_DRV_SUN4V)  += rtc-sun4v.o
> >> +obj-$(CONFIG_RTC_DRV_SUN6I)  += rtc-sun6i.o
> >>  obj-$(CONFIG_RTC_DRV_SUNXI)  += rtc-sunxi.o
> >>  obj-$(CONFIG_RTC_DRV_TEGRA)  += rtc-tegra.o
> >>  obj-$(CONFIG_RTC_DRV_TEST)   += rtc-test.o
> >> diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
> >> new file mode 100644
> >> index 0000000..fabd019
> >> --- /dev/null
> >> +++ b/drivers/rtc/rtc-sun6i.c
> >> @@ -0,0 +1,466 @@
> >> +/*
> >> + * An RTC driver for Allwinner A31/A23
> >> + *
> >> + * Copyright (c) 2014, Chen-Yu Tsai <wens at csie.org>
> >> + *
> >> + * based on rtc-sunxi.c
> >> + *
> >> + * An RTC driver for Allwinner A10/A20
> >> + *
> >> + * Copyright (c) 2013, Carlo Caione <carlo.caione at gmail.com>
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify
> >> + * it under the terms of the GNU General Public License as published by
> >> + * the Free Software Foundation; either version 2 of the License, or
> >> + * (at your option) any later version.
> >> + *
> >> + * This program is distributed in the hope that it will be useful, but WITHOUT
> >> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> >> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> >> + * more details.
> >> + */
> >> +
> >> +#include <linux/delay.h>
> >> +#include <linux/err.h>
> >> +#include <linux/fs.h>
> >> +#include <linux/init.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/io.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/module.h>
> >> +#include <linux/of.h>
> >> +#include <linux/of_address.h>
> >> +#include <linux/of_device.h>
> >> +#include <linux/platform_device.h>
> >> +#include <linux/rtc.h>
> >> +#include <linux/types.h>
> >> +
> >> +/* Control register */
> >> +#define SUN6I_LOSC_CTRL                              0x0000
> >> +#define SUN6I_LOSC_CTRL_ALM_DHMS_ACC         BIT(9)
> >> +#define SUN6I_LOSC_CTRL_RTC_HMS_ACC          BIT(8)
> >> +#define SUN6I_LOSC_CTRL_RTC_YMD_ACC          BIT(7)
> >> +#define SUN6I_LOSC_CTRL_ACC_MASK             (BIT(9) | BIT(8) | BIT(7))
> >
> > GENMASK maybe?
> 
> Fixed
> 
> >> +
> >> +/* RTC */
> >> +#define SUN6I_RTC_YMD                                0x0010
> >> +#define SUN6I_RTC_HMS                                0x0014
> >> +
> >> +/* Alarm 0 (counter) */
> >> +#define SUN6I_ALRM_COUNTER                   0x0020
> >> +#define SUN6I_ALRM_CUR_VAL                   0x0024
> >> +#define SUN6I_ALRM_EN                                0x0028
> >> +#define SUN6I_ALRM_EN_CNT_EN                 BIT(0)
> >> +#define SUN6I_ALRM_IRQ_EN                    0x002c
> >> +#define SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN         BIT(0)
> >> +#define SUN6I_ALRM_IRQ_STA                   0x0030
> >> +#define SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND              BIT(0)
> >> +
> >> +/* Alarm 1 (wall clock) */
> >> +#define SUN6I_ALRM1_EN                               0x0044
> >> +#define SUN6I_ALRM1_IRQ_EN                   0x0048
> >> +#define SUN6I_ALRM1_IRQ_STA                  0x004c
> >> +#define SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND    BIT(0)
> >> +
> >> +/* Alarm config */
> >> +#define SUN6I_ALARM_CONFIG                   0x0050
> >> +#define SUN6I_ALARM_CONFIG_WAKEUP            BIT(0)
> >> +
> >> +/* days / hours are 5 bit wide */
> >> +#define SUN6I_MASK_DH                                0x0000001f
> >> +/* seconds / minutes / years are 6 bit wide */
> >> +#define SUN6I_MASK_SMY                               0x0000003f
> >> +/* months are 4 bit wide */
> >> +#define SUN6I_MASK_M                         0x0000000f
> >> +/* leap year is single bit */
> >> +#define SUN6I_MASK_LY                                0x00000001
> >
> > Ditto
> 
> See below.
> 
> >> +
> >> +#define SUN6I_GET(x, mask, shift)            (((x) & ((mask) << (shift))) \
> >> +                                                     >> (shift))
> >> +
> >> +#define SUN6I_SET(x, mask, shift)            (((x) & (mask)) << (shift))
> >
> > Wouldn't it be easier to have the mask already shifted?
> 
> I'll just get rid of these 2 and the masks above, and inline them
> (in hex format) in the GET/SET macros below. How does that sound?

Sounds good to me.

> 
> >> +
> >> +/*
> >> + * Get date values
> >> + */
> >> +#define SUN6I_DATE_GET_DAY_VALUE(x)          SUN6I_GET(x, SUN6I_MASK_DH, 0)
> >> +#define SUN6I_DATE_GET_MON_VALUE(x)          SUN6I_GET(x, SUN6I_MASK_M, 8)
> >> +#define SUN6I_DATE_GET_YEAR_VALUE(x)         SUN6I_GET(x, SUN6I_MASK_SMY, 16)
> >> +
> >> +/*
> >> + * Get time values
> >> + */
> >> +#define SUN6I_TIME_GET_SEC_VALUE(x)          SUN6I_GET(x, SUN6I_MASK_SMY, 0)
> >> +#define SUN6I_TIME_GET_MIN_VALUE(x)          SUN6I_GET(x, SUN6I_MASK_SMY, 8)
> >> +#define SUN6I_TIME_GET_HOUR_VALUE(x)         SUN6I_GET(x, SUN6I_MASK_DH, 16)
> >> +
> >> +/*
> >> + * Set date values
> >> + */
> >> +#define SUN6I_DATE_SET_DAY_VALUE(x)          SUN6I_DATE_GET_DAY_VALUE(x)
> >> +#define SUN6I_DATE_SET_MON_VALUE(x)          SUN6I_SET(x, SUN6I_MASK_M, 8)
> >> +#define SUN6I_DATE_SET_YEAR_VALUE(x)         SUN6I_SET(x, SUN6I_MASK_SMY, 16)
> >> +#define SUN6I_LEAP_SET_VALUE(x)                      SUN6I_SET(x, SUN6I_MASK_LY, 22)
> >> +
> >> +/*
> >> + * Set time values
> >> + */
> >> +#define SUN6I_TIME_SET_SEC_VALUE(x)          SUN6I_TIME_GET_SEC_VALUE(x)
> >> +#define SUN6I_TIME_SET_MIN_VALUE(x)          SUN6I_SET(x, SUN6I_MASK_SMY, 8)
> >> +#define SUN6I_TIME_SET_HOUR_VALUE(x)         SUN6I_SET(x, SUN6I_MASK_DH, 16)
> >> +
> >> +/*
> >> + * The year parameter passed to the driver is usually an offset relative to
> >> + * the year 1900. This macro is used to convert this offset to another one
> >> + * relative to the minimum year allowed by the hardware.
> >> + *
> >> + * The year range is 1970 - 2033. This range is selected to match Allwinner's
> >> + * driver, even though it is somewhat limited.
> >> + */
> >> +#define SUN6I_YEAR_MIN                               1970
> >> +#define SUN6I_YEAR_MAX                               2033
> >> +#define SUN6I_YEAR_OFF                               (SUN6I_YEAR_MIN - 1900)
> >> +
> >> +struct sun6i_rtc_dev {
> >> +     struct rtc_device *rtc;
> >> +     struct device *dev;
> >> +     void __iomem *base;
> >> +     int irq;
> >> +     unsigned long alarm;
> >> +};
> >> +
> >> +static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
> >> +{
> >> +     struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id;
> >> +     u32 val;
> >> +
> >> +     val = readl(chip->base + SUN6I_ALRM_IRQ_STA);
> >> +
> >> +     if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) {
> >> +             val |= SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND;
> >> +             writel(val, chip->base + SUN6I_ALRM_IRQ_STA);
> >> +
> >> +             rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
> >> +
> >> +             return IRQ_HANDLED;
> >> +     }
> >> +
> >> +     return IRQ_NONE;
> >> +}
> >> +
> >> +static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
> >> +{
> >> +     u32 alrm_val = 0;
> >> +     u32 alrm_irq_val = 0;
> >> +     u32 alrm_wake_val = 0;
> >> +
> >> +     if (to) {
> >> +             alrm_val = SUN6I_ALRM_EN_CNT_EN;
> >> +             alrm_irq_val = SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN;
> >> +             alrm_wake_val = SUN6I_ALARM_CONFIG_WAKEUP;
> >> +     } else {
> >> +             writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
> >> +                             chip->base + SUN6I_ALRM_IRQ_STA);
> >> +     }
> >> +
> >> +     writel(alrm_val, chip->base + SUN6I_ALRM_EN);
> >> +     writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN);
> >> +     writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG);
> >> +}
> >> +
> >> +static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
> >> +{
> >> +     struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
> >> +     u32 date, time;
> >> +
> >> +     /*
> >> +      * read again in case it changes
> >> +      */
> >> +     do {
> >> +             date = readl(chip->base + SUN6I_RTC_YMD);
> >> +             time = readl(chip->base + SUN6I_RTC_HMS);
> >> +     } while ((date != readl(chip->base + SUN6I_RTC_YMD)) ||
> >> +              (time != readl(chip->base + SUN6I_RTC_HMS)));
> >> +
> >> +     rtc_tm->tm_sec  = SUN6I_TIME_GET_SEC_VALUE(time);
> >> +     rtc_tm->tm_min  = SUN6I_TIME_GET_MIN_VALUE(time);
> >> +     rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);
> >> +
> >> +     rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
> >> +     rtc_tm->tm_mon  = SUN6I_DATE_GET_MON_VALUE(date);
> >> +     rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
> >> +
> >> +     rtc_tm->tm_mon  -= 1;
> >> +
> >> +     /*
> >> +      * switch from (data_year->min)-relative offset to
> >> +      * a (1900)-relative one
> >> +      */
> >
> > I guess the reference to the structure field is not relevant anymore
> 
> Removed.
> 
> >> +     rtc_tm->tm_year += SUN6I_YEAR_OFF;
> >> +
> >> +     return rtc_valid_tm(rtc_tm);
> >> +}
> >> +
> >> +static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
> >> +{
> >> +     struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
> >> +     u32 alrm_st;
> >> +     u32 alrm_en;
> >> +
> >> +     alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN);
> >> +     alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA);
> >> +     wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN);
> >> +     wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN);
> >> +     rtc_time_to_tm(chip->alarm, &wkalrm->time);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
> >> +{
> >> +     struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
> >> +     struct rtc_time *alrm_tm = &wkalrm->time;
> >> +     struct rtc_time tm_now;
> >> +     unsigned long time_now = 0;
> >> +     unsigned long time_set = 0;
> >> +     unsigned long time_gap = 0;
> >> +     int ret = 0;
> >> +
> >> +     ret = sun6i_rtc_gettime(dev, &tm_now);
> >> +     if (ret < 0) {
> >> +             dev_err(dev, "Error in getting time\n");
> >> +             return -EINVAL;
> >> +     }
> >> +
> >> +     rtc_tm_to_time(alrm_tm, &time_set);
> >> +     rtc_tm_to_time(&tm_now, &time_now);
> >> +     if (time_set <= time_now) {
> >> +             dev_err(dev, "Date to set in the past\n");
> >> +             return -EINVAL;
> >> +     }
> >> +
> >> +     time_gap = time_set - time_now;
> >> +
> >> +     if (time_gap > U32_MAX) {
> >> +             dev_err(dev, "Date too far in the future\n");
> >> +             return -EINVAL;
> >> +     }
> >> +
> >> +     sun6i_rtc_setaie(0, chip);
> >> +     writel(0, chip->base + SUN6I_ALRM_COUNTER);
> >> +     usleep_range(100, 300);
> >> +
> >> +     writel(time_gap, chip->base + SUN6I_ALRM_COUNTER);
> >> +     chip->alarm = time_set;
> >> +
> >> +     sun6i_rtc_setaie(wkalrm->enabled, chip);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int sun6i_rtc_wait(struct sun6i_rtc_dev *chip, int offset,
> >> +                       unsigned int mask, unsigned int ms_timeout)
> >> +{
> >> +     const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);
> >> +     u32 reg;
> >> +
> >> +     do {
> >> +             reg = readl(chip->base + offset);
> >> +             reg &= mask;
> >> +
> >> +             if (!reg)
> >> +                     return 0;
> >> +
> >> +     } while (time_before(jiffies, timeout));
> >> +
> >> +     return -ETIMEDOUT;
> >> +}
> >> +
> >> +static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
> >> +{
> >> +     struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
> >> +     u32 date = 0;
> >> +     u32 time = 0;
> >> +     int year;
> >> +
> >> +     /*
> >> +      * the input rtc_tm->tm_year is the offset relative to 1900. We use
> >> +      * the SUN6I_YEAR_OFF macro to rebase it with respect to the min year
> >> +      * allowed by the hardware
> >> +      */
> >> +
> >> +     year = rtc_tm->tm_year + 1900;
> >> +     if (year < SUN6I_YEAR_MIN || year > SUN6I_YEAR_MAX) {
> >> +             dev_err(dev, "rtc only supports year in range %d - %d\n",
> >> +                             SUN6I_YEAR_MIN, SUN6I_YEAR_MAX);
> >> +             return -EINVAL;
> >> +     }
> >> +
> >> +     rtc_tm->tm_year -= SUN6I_YEAR_OFF;
> >> +     rtc_tm->tm_mon += 1;
> >> +
> >> +     date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
> >> +             SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |
> >> +             SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
> >> +
> >> +     if (is_leap_year(year))
> >> +             date |= SUN6I_LEAP_SET_VALUE(1);
> >> +
> >> +     time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec)  |
> >> +             SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min)  |
> >> +             SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);
> >> +
> >> +     /* Check whether registers are writable */
> >> +     if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
> >> +                             SUN6I_LOSC_CTRL_ACC_MASK, 50)) {
> >> +             dev_err(dev, "rtc is still busy.\n");
> >> +             return -EBUSY;
> >> +     }
> >> +
> >> +     writel(time, chip->base + SUN6I_RTC_HMS);
> >> +
> >> +     /*
> >> +      * After writing the RTC HH-MM-SS register, the
> >> +      * SUN6I_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not
> >> +      * be cleared until the real writing operation is finished
> >> +      */
> >> +
> >> +     if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
> >> +                             SUN6I_LOSC_CTRL_RTC_HMS_ACC, 50)) {
> >> +             dev_err(dev, "Failed to set rtc time.\n");
> >> +             return -ETIMEDOUT;
> >> +     }
> >> +
> >> +     writel(date, chip->base + SUN6I_RTC_YMD);
> >> +
> >> +     /*
> >> +      * After writing the RTC YY-MM-DD register, the
> >> +      * SUN6I_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not
> >> +      * be cleared until the real writing operation is finished
> >> +      */
> >> +
> >> +     if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
> >> +                             SUN6I_LOSC_CTRL_RTC_YMD_ACC, 50)) {
> >> +             dev_err(dev, "Failed to set rtc time.\n");
> >> +             return -ETIMEDOUT;
> >> +     }
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int sun6i_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
> >> +{
> >> +     struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
> >> +
> >> +     if (!enabled)
> >> +             sun6i_rtc_setaie(enabled, chip);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static const struct rtc_class_ops sun6i_rtc_ops = {
> >> +     .read_time              = sun6i_rtc_gettime,
> >> +     .set_time               = sun6i_rtc_settime,
> >> +     .read_alarm             = sun6i_rtc_getalarm,
> >> +     .set_alarm              = sun6i_rtc_setalarm,
> >> +     .alarm_irq_enable       = sun6i_rtc_alarm_irq_enable
> >> +};
> >> +
> >> +static const struct of_device_id sun6i_rtc_dt_ids[] = {
> >> +     { .compatible = "allwinner,sun6i-a31-rtc" },
> >> +     { /* sentinel */ },
> >> +};
> >> +MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);
> >
> > I guess you can move this down just before the platform_driver
> > declaration if you don't need it in probe.
> 
> Moved.
> 
> >> +
> >> +static int sun6i_rtc_probe(struct platform_device *pdev)
> >> +{
> >> +     struct sun6i_rtc_dev *chip;
> >> +     struct resource *res;
> >> +     int ret;
> >> +
> >> +     chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
> >> +     if (!chip)
> >> +             return -ENOMEM;
> >> +
> >> +     platform_set_drvdata(pdev, chip);
> >> +     chip->dev = &pdev->dev;
> >> +
> >> +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> +     chip->base = devm_ioremap_resource(&pdev->dev, res);
> >> +     if (IS_ERR(chip->base))
> >> +             return PTR_ERR(chip->base);
> >> +
> >> +     chip->irq = platform_get_irq(pdev, 0);
> >> +     if (chip->irq < 0) {
> >> +             dev_err(&pdev->dev, "No IRQ resource\n");
> >> +             return chip->irq;
> >> +     }
> >
> > Newline
> 
> Added.
> 
> >> +     ret = devm_request_irq(&pdev->dev, chip->irq, sun6i_rtc_alarmirq,
> >> +                     0, dev_name(&pdev->dev), chip);
> >> +     if (ret) {
> >> +             dev_err(&pdev->dev, "Could not request IRQ\n");
> >> +             return ret;
> >> +     }
> >> +
> >> +     /* clear the alarm counter value */
> >> +     writel(0, chip->base + SUN6I_ALRM_COUNTER);
> >> +
> >> +     /* disable counter alarm */
> >> +     writel(0, chip->base + SUN6I_ALRM_EN);
> >> +
> >> +     /* disable counter alarm interrupt */
> >> +     writel(0, chip->base + SUN6I_ALRM_IRQ_EN);
> >> +
> >> +     /* disable week alarm */
> >> +     writel(0, chip->base + SUN6I_ALRM1_EN);
> >> +
> >> +     /* disable week alarm interrupt */
> >> +     writel(0, chip->base + SUN6I_ALRM1_IRQ_EN);
> >> +
> >> +     /* clear counter alarm pending interrupts */
> >> +     writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base +
> >> +                     SUN6I_ALRM_IRQ_STA);
> >> +
> >> +     /* clear week alarm pending interrupts */
> >> +     writel(SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND, chip->base +
> >> +                     SUN6I_ALRM1_IRQ_STA);
> >> +
> >> +     /* disable alarm wakeup */
> >> +     writel(0, chip->base + SUN6I_ALARM_CONFIG);
> >> +
> >> +     chip->rtc = rtc_device_register("rtc-sun6i", &pdev->dev,
> >> +                     &sun6i_rtc_ops, THIS_MODULE);
> >> +     if (IS_ERR(chip->rtc)) {
> >> +             dev_err(&pdev->dev, "unable to register device\n");
> >> +             return PTR_ERR(chip->rtc);
> >> +     }
> >> +
> >> +     dev_info(&pdev->dev, "RTC enabled\n");
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int sun6i_rtc_remove(struct platform_device *pdev)
> >> +{
> >> +     struct sun6i_rtc_dev *chip = platform_get_drvdata(pdev);
> >> +
> >> +     rtc_device_unregister(chip->rtc);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static struct platform_driver sun6i_rtc_driver = {
> >> +     .probe          = sun6i_rtc_probe,
> >> +     .remove         = sun6i_rtc_remove,
> >> +     .driver         = {
> >> +             .name           = "sun6i-rtc",
> >> +             .owner          = THIS_MODULE,
> >> +             .of_match_table = sun6i_rtc_dt_ids,
> >> +     },
> >> +};
> >> +
> >> +module_platform_driver(sun6i_rtc_driver);
> >> +
> >> +MODULE_DESCRIPTION("sun6i RTC driver");
> >> +MODULE_AUTHOR("Chen-Yu Tsai <wens at csie.org>");
> >> +MODULE_LICENSE("GPL");
> >> --
> >> 2.0.1
> >>
> >
> > Thanks!
> > Maxime
> 
> Thanks for the review!
> ChenYu

Thanks for your efforts on this,
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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