[rtc-linux] Re: [PATCH v5 3/7] rtc: ac100: Add RTC driver for X-Powers AC100

[Lee Jones <lee.jones@linaro.org>]

On Fri, 08 Jul 2016, Alexandre Belloni wrote:

> On 08/07/2016 at 22:33:38 +0800, Chen-Yu Tsai wrote :
> > X-Powers AC100 is a codec / RTC combo chip. This driver supports
> > the RTC sub-device.
> >=20
> > The RTC block also has clock outputs and non-volatile storage.
> > Non-volatile storage wthin the RTC hardware is not supported.
> > Clock output support is added in the next patch.
> >=20
> > Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Applied, thanks.

> > ---
> > Changes since v4:
> >=20
> >   - None.
> >=20
> > Changes since v3:
> >=20
> >   - Moved month/year conversion offsets inline with reg[] assignments
> >   - Used platform_get_irq instead of of_get_irq
> >   - Dropped separate mutex and use rtc->ops_lock in interrupt handler
> >   - Dropped of_irq.h from includes
> >   - Added of_device_id and .of_match_table
> >=20
> > Changes since v2:
> >=20
> >   - Fixed off-by-1 errors in register mask macros
> >   - Fixed copy-paste error in set_alarm function
> >   - Drop uie_unsupported, since the alarm works now
> >   - Fixed up copyright notice
> >   - Changed license to GPL v2, matching mfd driver
> >=20
> > ---
> >  drivers/rtc/Kconfig     |  10 ++
> >  drivers/rtc/Makefile    |   1 +
> >  drivers/rtc/rtc-ac100.c | 325 ++++++++++++++++++++++++++++++++++++++++=
++++++++
> >  3 files changed, 336 insertions(+)
> >  create mode 100644 drivers/rtc/rtc-ac100.c
> >=20
> > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> > index 18639e0cb6e2..b9d7cbb6bd76 100644
> > --- a/drivers/rtc/Kconfig
> > +++ b/drivers/rtc/Kconfig
> > @@ -183,6 +183,16 @@ config RTC_DRV_ABX80X
> >  	  This driver can also be built as a module. If so, the module
> >  	  will be called rtc-abx80x.
> > =20
> > +config RTC_DRV_AC100
> > +	tristate "X-Powers AC100"
> > +	depends on MFD_AC100
> > +	help
> > +	  If you say yes here you get support for the real-time clock found
> > +	  in X-Powers AC100 family peripheral ICs.
> > +
> > +	  This driver can also be built as a module. If so, the module
> > +	  will be called rtc-ac100.
> > +
> >  config RTC_DRV_AS3722
> >  	tristate "ams AS3722 RTC driver"
> >  	depends on MFD_AS3722
> > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> > index ea2833723fa9..b07c28779573 100644
> > --- a/drivers/rtc/Makefile
> > +++ b/drivers/rtc/Makefile
> > @@ -26,6 +26,7 @@ obj-$(CONFIG_RTC_DRV_AB3100)	+=3D rtc-ab3100.o
> >  obj-$(CONFIG_RTC_DRV_AB8500)	+=3D rtc-ab8500.o
> >  obj-$(CONFIG_RTC_DRV_ABB5ZES3)	+=3D rtc-ab-b5ze-s3.o
> >  obj-$(CONFIG_RTC_DRV_ABX80X)	+=3D rtc-abx80x.o
> > +obj-$(CONFIG_RTC_DRV_AC100)	+=3D rtc-ac100.o
> >  obj-$(CONFIG_RTC_DRV_ARMADA38X)	+=3D rtc-armada38x.o
> >  obj-$(CONFIG_RTC_DRV_AS3722)	+=3D rtc-as3722.o
> >  obj-$(CONFIG_RTC_DRV_ASM9260)	+=3D rtc-asm9260.o
> > diff --git a/drivers/rtc/rtc-ac100.c b/drivers/rtc/rtc-ac100.c
> > new file mode 100644
> > index 000000000000..5a9ca89d04c7
> > --- /dev/null
> > +++ b/drivers/rtc/rtc-ac100.c
> > @@ -0,0 +1,325 @@
> > +/*
> > + * RTC Driver for X-Powers AC100
> > + *
> > + * Copyright (c) 2016 Chen-Yu Tsai
> > + *
> > + * Chen-Yu Tsai <wens@csie.org>
> > + *
> > + * This program is free software; you can redistribute it and/or modif=
y
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + *
> > + * 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 Licen=
se for
> > + * more details.
> > + */
> > +
> > +#include <linux/bcd.h>
> > +#include <linux/device.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/kernel.h>
> > +#include <linux/mfd/ac100.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/rtc.h>
> > +#include <linux/types.h>
> > +
> > +/* Control register */
> > +#define AC100_RTC_CTRL_24HOUR	BIT(0)
> > +
> > +/* RTC */
> > +#define AC100_RTC_SEC_MASK	GENMASK(6, 0)
> > +#define AC100_RTC_MIN_MASK	GENMASK(6, 0)
> > +#define AC100_RTC_HOU_MASK	GENMASK(5, 0)
> > +#define AC100_RTC_WEE_MASK	GENMASK(2, 0)
> > +#define AC100_RTC_DAY_MASK	GENMASK(5, 0)
> > +#define AC100_RTC_MON_MASK	GENMASK(4, 0)
> > +#define AC100_RTC_YEA_MASK	GENMASK(7, 0)
> > +#define AC100_RTC_YEA_LEAP	BIT(15)
> > +#define AC100_RTC_UPD_TRIGGER	BIT(15)
> > +
> > +/* Alarm (wall clock) */
> > +#define AC100_ALM_INT_ENABLE	BIT(0)
> > +
> > +#define AC100_ALM_SEC_MASK	GENMASK(6, 0)
> > +#define AC100_ALM_MIN_MASK	GENMASK(6, 0)
> > +#define AC100_ALM_HOU_MASK	GENMASK(5, 0)
> > +#define AC100_ALM_WEE_MASK	GENMASK(2, 0)
> > +#define AC100_ALM_DAY_MASK	GENMASK(5, 0)
> > +#define AC100_ALM_MON_MASK	GENMASK(4, 0)
> > +#define AC100_ALM_YEA_MASK	GENMASK(7, 0)
> > +#define AC100_ALM_ENABLE_FLAG	BIT(15)
> > +#define AC100_ALM_UPD_TRIGGER	BIT(15)
> > +
> > +/*
> > + * The year parameter passed to the driver is usually an offset relati=
ve 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 - 2069. This range is selected to match Allw=
inner's
> > + * driver.
> > + */
> > +#define AC100_YEAR_MIN				1970
> > +#define AC100_YEAR_MAX				2069
> > +#define AC100_YEAR_OFF				(AC100_YEAR_MIN - 1900)
> > +
> > +struct ac100_rtc_dev {
> > +	struct rtc_device *rtc;
> > +	struct device *dev;
> > +	struct regmap *regmap;
> > +	int irq;
> > +	unsigned long alarm;
> > +};
> > +
> > +static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc=
_tm)
> > +{
> > +	struct ac100_rtc_dev *chip =3D dev_get_drvdata(dev);
> > +	struct regmap *regmap =3D chip->regmap;
> > +	u16 reg[7];
> > +	int ret;
> > +
> > +	ret =3D regmap_bulk_read(regmap, AC100_RTC_SEC, reg, 7);
> > +	if (ret)
> > +		return ret;
> > +
> > +	rtc_tm->tm_sec  =3D bcd2bin(reg[0] & AC100_RTC_SEC_MASK);
> > +	rtc_tm->tm_min  =3D bcd2bin(reg[1] & AC100_RTC_MIN_MASK);
> > +	rtc_tm->tm_hour =3D bcd2bin(reg[2] & AC100_RTC_HOU_MASK);
> > +	rtc_tm->tm_wday =3D bcd2bin(reg[3] & AC100_RTC_WEE_MASK);
> > +	rtc_tm->tm_mday =3D bcd2bin(reg[4] & AC100_RTC_DAY_MASK);
> > +	rtc_tm->tm_mon  =3D bcd2bin(reg[5] & AC100_RTC_MON_MASK) - 1;
> > +	rtc_tm->tm_year =3D bcd2bin(reg[6] & AC100_RTC_YEA_MASK) +
> > +			  AC100_YEAR_OFF;
> > +
> > +	return rtc_valid_tm(rtc_tm);
> > +}
> > +
> > +static int ac100_rtc_set_time(struct device *dev, struct rtc_time *rtc=
_tm)
> > +{
> > +	struct ac100_rtc_dev *chip =3D dev_get_drvdata(dev);
> > +	struct regmap *regmap =3D chip->regmap;
> > +	int year;
> > +	u16 reg[8];
> > +
> > +	/* our RTC has a limited year range... */
> > +	year =3D rtc_tm->tm_year - AC100_YEAR_OFF;
> > +	if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
> > +		dev_err(dev, "rtc only supports year in range %d - %d\n",
> > +			AC100_YEAR_MIN, AC100_YEAR_MAX);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* convert to BCD */
> > +	reg[0] =3D bin2bcd(rtc_tm->tm_sec)     & AC100_RTC_SEC_MASK;
> > +	reg[1] =3D bin2bcd(rtc_tm->tm_min)     & AC100_RTC_MIN_MASK;
> > +	reg[2] =3D bin2bcd(rtc_tm->tm_hour)    & AC100_RTC_HOU_MASK;
> > +	reg[3] =3D bin2bcd(rtc_tm->tm_wday)    & AC100_RTC_WEE_MASK;
> > +	reg[4] =3D bin2bcd(rtc_tm->tm_mday)    & AC100_RTC_DAY_MASK;
> > +	reg[5] =3D bin2bcd(rtc_tm->tm_mon + 1) & AC100_RTC_MON_MASK;
> > +	reg[6] =3D bin2bcd(year)		     & AC100_RTC_YEA_MASK;
> > +	/* trigger write */
> > +	reg[7] =3D AC100_RTC_UPD_TRIGGER;
> > +
> > +	/* Is it a leap year? */
> > +	if (is_leap_year(year + AC100_YEAR_OFF + 1900))
> > +		reg[6] |=3D AC100_RTC_YEA_LEAP;
> > +
> > +	return regmap_bulk_write(regmap, AC100_RTC_SEC, reg, 8);
> > +}
> > +
> > +static int ac100_rtc_alarm_irq_enable(struct device *dev, unsigned int=
 en)
> > +{
> > +	struct ac100_rtc_dev *chip =3D dev_get_drvdata(dev);
> > +	struct regmap *regmap =3D chip->regmap;
> > +	unsigned int val;
> > +
> > +	val =3D en ? AC100_ALM_INT_ENABLE : 0;
> > +
> > +	return regmap_write(regmap, AC100_ALM_INT_ENA, val);
> > +}
> > +
> > +static int ac100_rtc_get_alarm(struct device *dev, struct rtc_wkalrm *=
alrm)
> > +{
> > +	struct ac100_rtc_dev *chip =3D dev_get_drvdata(dev);
> > +	struct regmap *regmap =3D chip->regmap;
> > +	struct rtc_time *alrm_tm =3D &alrm->time;
> > +	u16 reg[7];
> > +	unsigned int val;
> > +	int ret;
> > +
> > +	ret =3D regmap_read(regmap, AC100_ALM_INT_ENA, &val);
> > +	if (ret)
> > +		return ret;
> > +
> > +	alrm->enabled =3D !!(val & AC100_ALM_INT_ENABLE);
> > +
> > +	ret =3D regmap_bulk_read(regmap, AC100_ALM_SEC, reg, 7);
> > +	if (ret)
> > +		return ret;
> > +
> > +	alrm_tm->tm_sec  =3D bcd2bin(reg[0] & AC100_ALM_SEC_MASK);
> > +	alrm_tm->tm_min  =3D bcd2bin(reg[1] & AC100_ALM_MIN_MASK);
> > +	alrm_tm->tm_hour =3D bcd2bin(reg[2] & AC100_ALM_HOU_MASK);
> > +	alrm_tm->tm_wday =3D bcd2bin(reg[3] & AC100_ALM_WEE_MASK);
> > +	alrm_tm->tm_mday =3D bcd2bin(reg[4] & AC100_ALM_DAY_MASK);
> > +	alrm_tm->tm_mon  =3D bcd2bin(reg[5] & AC100_ALM_MON_MASK) - 1;
> > +	alrm_tm->tm_year =3D bcd2bin(reg[6] & AC100_ALM_YEA_MASK) +
> > +			   AC100_YEAR_OFF;
> > +
> > +	return 0;
> > +}
> > +
> > +static int ac100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *=
alrm)
> > +{
> > +	struct ac100_rtc_dev *chip =3D dev_get_drvdata(dev);
> > +	struct regmap *regmap =3D chip->regmap;
> > +	struct rtc_time *alrm_tm =3D &alrm->time;
> > +	u16 reg[8];
> > +	int year;
> > +	int ret;
> > +
> > +	/* our alarm has a limited year range... */
> > +	year =3D alrm_tm->tm_year - AC100_YEAR_OFF;
> > +	if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
> > +		dev_err(dev, "alarm only supports year in range %d - %d\n",
> > +			AC100_YEAR_MIN, AC100_YEAR_MAX);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* convert to BCD */
> > +	reg[0] =3D (bin2bcd(alrm_tm->tm_sec)  & AC100_ALM_SEC_MASK) |
> > +			AC100_ALM_ENABLE_FLAG;
> > +	reg[1] =3D (bin2bcd(alrm_tm->tm_min)  & AC100_ALM_MIN_MASK) |
> > +			AC100_ALM_ENABLE_FLAG;
> > +	reg[2] =3D (bin2bcd(alrm_tm->tm_hour) & AC100_ALM_HOU_MASK) |
> > +			AC100_ALM_ENABLE_FLAG;
> > +	/* Do not enable weekday alarm */
> > +	reg[3] =3D bin2bcd(alrm_tm->tm_wday) & AC100_ALM_WEE_MASK;
> > +	reg[4] =3D (bin2bcd(alrm_tm->tm_mday) & AC100_ALM_DAY_MASK) |
> > +			AC100_ALM_ENABLE_FLAG;
> > +	reg[5] =3D (bin2bcd(alrm_tm->tm_mon + 1)  & AC100_ALM_MON_MASK) |
> > +			AC100_ALM_ENABLE_FLAG;
> > +	reg[6] =3D (bin2bcd(year) & AC100_ALM_YEA_MASK) |
> > +			AC100_ALM_ENABLE_FLAG;
> > +	/* trigger write */
> > +	reg[7] =3D AC100_ALM_UPD_TRIGGER;
> > +
> > +	ret =3D regmap_bulk_write(regmap, AC100_ALM_SEC, reg, 8);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return ac100_rtc_alarm_irq_enable(dev, alrm->enabled);
> > +}
> > +
> > +static irqreturn_t ac100_rtc_irq(int irq, void *data)
> > +{
> > +	struct ac100_rtc_dev *chip =3D data;
> > +	struct regmap *regmap =3D chip->regmap;
> > +	unsigned int val =3D 0;
> > +	int ret;
> > +
> > +	mutex_lock(&chip->rtc->ops_lock);
> > +
> > +	/* read status */
> > +	ret =3D regmap_read(regmap, AC100_ALM_INT_STA, &val);
> > +	if (ret)
> > +		goto out;
> > +
> > +	if (val & AC100_ALM_INT_ENABLE) {
> > +		/* signal rtc framework */
> > +		rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
> > +
> > +		/* clear status */
> > +		ret =3D regmap_write(regmap, AC100_ALM_INT_STA, val);
> > +		if (ret)
> > +			goto out;
> > +
> > +		/* disable interrupt */
> > +		ret =3D ac100_rtc_alarm_irq_enable(chip->dev, 0);
> > +		if (ret)
> > +			goto out;
> > +	}
> > +
> > +out:
> > +	mutex_unlock(&chip->rtc->ops_lock);
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static const struct rtc_class_ops ac100_rtc_ops =3D {
> > +	.read_time	  =3D ac100_rtc_get_time,
> > +	.set_time	  =3D ac100_rtc_set_time,
> > +	.read_alarm	  =3D ac100_rtc_get_alarm,
> > +	.set_alarm	  =3D ac100_rtc_set_alarm,
> > +	.alarm_irq_enable =3D ac100_rtc_alarm_irq_enable,
> > +};
> > +
> > +static int ac100_rtc_probe(struct platform_device *pdev)
> > +{
> > +	struct ac100_dev *ac100 =3D dev_get_drvdata(pdev->dev.parent);
> > +	struct ac100_rtc_dev *chip;
> > +	int ret;
> > +
> > +	chip =3D devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
> > +	platform_set_drvdata(pdev, chip);
> > +	chip->dev =3D &pdev->dev;
> > +	chip->regmap =3D ac100->regmap;
> > +
> > +	chip->irq =3D platform_get_irq(pdev, 0);
> > +	if (chip->irq < 0) {
> > +		dev_err(&pdev->dev, "No IRQ resource\n");
> > +		return chip->irq;
> > +	}
> > +
> > +	ret =3D devm_request_threaded_irq(&pdev->dev, chip->irq, NULL,
> > +					ac100_rtc_irq,
> > +					IRQF_SHARED | IRQF_ONESHOT,
> > +					dev_name(&pdev->dev), chip);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "Could not request IRQ\n");
> > +		return ret;
> > +	}
> > +
> > +	/* always use 24 hour mode */
> > +	regmap_write_bits(chip->regmap, AC100_RTC_CTRL, AC100_RTC_CTRL_24HOUR=
,
> > +			  AC100_RTC_CTRL_24HOUR);
> > +
> > +	/* disable counter alarm interrupt */
> > +	regmap_write(chip->regmap, AC100_ALM_INT_ENA, 0);
> > +
> > +	/* clear counter alarm pending interrupts */
> > +	regmap_write(chip->regmap, AC100_ALM_INT_STA, AC100_ALM_INT_ENABLE);
> > +
> > +	chip->rtc =3D devm_rtc_device_register(&pdev->dev, "rtc-ac100",
> > +					     &ac100_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 const struct of_device_id ac100_rtc_match[] =3D {
> > +	{ .compatible =3D "x-powers,ac100-rtc" },
> > +	{ },
> > +};
> > +MODULE_DEVICE_TABLE(of, ac100_rtc_match);
> > +
> > +static struct platform_driver ac100_rtc_driver =3D {
> > +	.probe		=3D ac100_rtc_probe,
> > +	.driver		=3D {
> > +		.name		=3D "ac100-rtc",
> > +		.of_match_table	=3D of_match_ptr(ac100_rtc_match),
> > +	},
> > +};
> > +module_platform_driver(ac100_rtc_driver);
> > +
> > +MODULE_DESCRIPTION("X-Powers AC100 RTC driver");
> > +MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
> > +MODULE_LICENSE("GPL v2");
>=20

--=20
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org =E2=94=82 Open source software for ARM SoCs
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