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Date:   Mon, 2 Dec 2019 10:39:35 +0100
From:   Alexandre Belloni <alexandre.belloni@bootlin.com>
To:     Andreas Kemnade <andreas@kemnade.info>
Cc:     lee.jones@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com,
        a.zummo@towertech.it, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-rtc@vger.kernel.org,
        stefan@agner.ch, b.galvani@gmail.com, phh@phh.me,
        letux-kernel@openphoenux.org
Subject: Re: [PATCH v3 6/6] rtc: rtc-rc5t619: add ricoh rc5t619 RTC driver
Message-ID: <20191202093935.GA909634@piout.net>
References: <20191129212045.18325-1-andreas@kemnade.info>
 <20191129212045.18325-7-andreas@kemnade.info>
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In-Reply-To: <20191129212045.18325-7-andreas@kemnade.info>
User-Agent: Mutt/1.12.1 (2019-06-15)
Sender: linux-kernel-owner@vger.kernel.org
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On 29/11/2019 22:20:45+0100, Andreas Kemnade wrote:
> Add an RTC driver for the RTC device on Ricoh MFD rc5t619,
> which is implemented as a variant of rn5t618.
> 
> rtc-range output:
> Testing 2000-02-28 23:59:59.
> OK
> 
> Testing 2038-01-19 03:14:07.
> OK
> 
> Testing 2069-12-31 23:59:59.
> OK
> 
> Testing 2099-12-31 23:59:59.
> KO RTC_RD_TIME returned 22 (line 138)
> 
> Testing 2100-02-28 23:59:59.
> KO RTC_SET_TIME returned 34 (line 122)
> 
> Testing 2106-02-07 06:28:15.
> KO RTC_SET_TIME returned 34 (line 122)
> 
> Testing 2262-04-11 23:47:16.
> KO RTC_SET_TIME returned 34 (line 122)
> 
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

> ---
> - further output cleanup
> - remove useless toggling of alarm flag in rtc probe
> - alignment cleanup
> 
> Changes in v2:
> - correct subject line
> - reset pon flag not at probe but later
> - initialize things only on pon
> - 12h handling
> - ranges
> - style cleanup
> - less magic values
> 
>  drivers/rtc/Kconfig       |  10 +
>  drivers/rtc/Makefile      |   1 +
>  drivers/rtc/rtc-rc5t619.c | 462 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 473 insertions(+)
>  create mode 100644 drivers/rtc/rtc-rc5t619.c
> 
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 1adf9f815652..b8e5bfa8efc6 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -600,6 +600,16 @@ config RTC_DRV_RC5T583
>  	  This driver can also be built as a module. If so, the module
>  	  will be called rtc-rc5t583.
>  
> +config RTC_DRV_RC5T619
> +	tristate "RICOH RC5T619 RTC driver"
> +	depends on MFD_RN5T618
> +	help
> +	  If you say yes here you get support for the RTC on the
> +	  RICOH RC5T619 chips.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called rtc-rc5t619.
> +
>  config RTC_DRV_S35390A
>  	tristate "Seiko Instruments S-35390A"
>  	select BITREVERSE
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 4ac8f19fb631..7612912cdf00 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -137,6 +137,7 @@ obj-$(CONFIG_RTC_DRV_PXA)	+= rtc-pxa.o
>  obj-$(CONFIG_RTC_DRV_R7301)	+= rtc-r7301.o
>  obj-$(CONFIG_RTC_DRV_R9701)	+= rtc-r9701.o
>  obj-$(CONFIG_RTC_DRV_RC5T583)	+= rtc-rc5t583.o
> +obj-$(CONFIG_RTC_DRV_RC5T619)	+= rtc-rc5t619.o
>  obj-$(CONFIG_RTC_DRV_RK808)	+= rtc-rk808.o
>  obj-$(CONFIG_RTC_DRV_RP5C01)	+= rtc-rp5c01.o
>  obj-$(CONFIG_RTC_DRV_RS5C313)	+= rtc-rs5c313.o
> diff --git a/drivers/rtc/rtc-rc5t619.c b/drivers/rtc/rtc-rc5t619.c
> new file mode 100644
> index 000000000000..1860f3e7f6e7
> --- /dev/null
> +++ b/drivers/rtc/rtc-rc5t619.c
> @@ -0,0 +1,462 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * drivers/rtc/rtc-rc5t619.c
> + *
> + * Real time clock driver for RICOH RC5T619 power management chip.
> + *
> + * Copyright (C) 2019 Andreas Kemnade
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/mfd/rn5t618.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/bcd.h>
> +#include <linux/rtc.h>
> +#include <linux/slab.h>
> +#include <linux/irqdomain.h>
> +
> +struct rc5t619_rtc {
> +	int			irq;
> +	struct rtc_device	*rtc;
> +	struct rn5t618 *rn5t618;
> +};
> +
> +#define CTRL1_ALARM_ENABLED 0x40
> +#define CTRL1_24HR 0x20
> +#define CTRL1_PERIODIC_MASK 0xf
> +
> +#define CTRL2_PON 0x10
> +#define CTRL2_ALARM_STATUS 0x80
> +#define CTRL2_CTFG 0x4
> +#define CTRL2_CTC 0x1
> +
> +#define MONTH_CENTFLAG 0x80
> +#define HOUR_PMFLAG 0x20
> +#define MDAY_DAL_EXT 0x80
> +
> +static uint8_t rtc5t619_12hour_bcd2bin(uint8_t hour)
> +{
> +	if (hour & HOUR_PMFLAG) {
> +		hour = bcd2bin(hour & ~HOUR_PMFLAG);
> +		return hour == 12 ? 12 : 12 + hour;
> +	}
> +
> +	hour = bcd2bin(hour);
> +	return hour == 12 ? 0 : hour;
> +}
> +
> +static uint8_t rtc5t619_12hour_bin2bcd(uint8_t hour)
> +{
> +	if (!hour)
> +		return 0x12;
> +
> +	if (hour < 12)
> +		return bin2bcd(hour);
> +
> +	if (hour == 12)
> +		return 0x12 | HOUR_PMFLAG;
> +
> +	return bin2bcd(hour - 12) | HOUR_PMFLAG;
> +}
> +
> +static int rc5t619_rtc_periodic_disable(struct device *dev)
> +{
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +	int err;
> +
> +	/* disable function */
> +	err = regmap_update_bits(rtc->rn5t618->regmap,
> +				 RN5T618_RTC_CTRL1, CTRL1_PERIODIC_MASK, 0);
> +	if (err < 0)
> +		return err;
> +
> +	/* clear alarm flag and CTFG */
> +	err = regmap_update_bits(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2,
> +				 CTRL2_ALARM_STATUS | CTRL2_CTFG | CTRL2_CTC,
> +				 0);
> +	if (err < 0)
> +		return err;
> +
> +	return 0;
> +}
> +
> +/* things to be done once after power on */
> +static int rc5t619_rtc_pon_setup(struct device *dev)
> +{
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +	int err;
> +	unsigned int reg_data;
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &reg_data);
> +	if (err < 0)
> +		return err;
> +
> +	/* clear VDET PON */
> +	reg_data &= ~(CTRL2_PON | CTRL2_CTC | 0x4a);	/* 0101-1011 */
> +	reg_data |= 0x20;	/* 0010-0000 */
> +	err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, reg_data);
> +	if (err < 0)
> +		return err;
> +
> +	/* clearing RTC Adjust register */
> +	err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_ADJUST, 0);
> +	if (err)
> +		return err;
> +
> +	return regmap_update_bits(rtc->rn5t618->regmap,
> +					RN5T618_RTC_CTRL1,
> +					CTRL1_24HR, CTRL1_24HR);
> +}
> +
> +static int rc5t619_rtc_read_time(struct device *dev, struct rtc_time *tm)
> +{
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +	u8 buff[7];
> +	int err;
> +	int cent_flag;
> +	unsigned int ctrl1;
> +	unsigned int ctrl2;
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
> +	if (err < 0)
> +		return err;
> +
> +	if (ctrl2 & CTRL2_PON)
> +		return -EINVAL;
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
> +	if (err < 0)
> +		return err;
> +
> +	err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS,
> +			       buff, sizeof(buff));
> +	if (err < 0)
> +		return err;
> +
> +	if (buff[5] & MONTH_CENTFLAG)
> +		cent_flag = 1;
> +	else
> +		cent_flag = 0;
> +
> +	tm->tm_sec  = bcd2bin(buff[0]);
> +	tm->tm_min  = bcd2bin(buff[1]);
> +
> +	if (ctrl1 & CTRL1_24HR)
> +		tm->tm_hour = bcd2bin(buff[2]);
> +	else
> +		tm->tm_hour = rtc5t619_12hour_bcd2bin(buff[2]);
> +
> +	tm->tm_wday = bcd2bin(buff[3]);
> +	tm->tm_mday = bcd2bin(buff[4]);
> +	tm->tm_mon  = bcd2bin(buff[5] & 0x1f) - 1; /* back to system 0-11 */
> +	tm->tm_year = bcd2bin(buff[6]) + 100 * cent_flag;
> +
> +	return 0;
> +}
> +
> +static int rc5t619_rtc_set_time(struct device *dev, struct rtc_time *tm)
> +{
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +	u8 buff[7];
> +	int err;
> +	int cent_flag;
> +	unsigned int ctrl1;
> +	unsigned int ctrl2;
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
> +	if (err < 0)
> +		return err;
> +
> +	if (ctrl2 & CTRL2_PON)
> +		rc5t619_rtc_pon_setup(dev);
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
> +	if (err < 0)
> +		return err;
> +
> +	if (tm->tm_year >= 100)
> +		cent_flag = 1;
> +	else
> +		cent_flag = 0;
> +
> +	buff[0] = bin2bcd(tm->tm_sec);
> +	buff[1] = bin2bcd(tm->tm_min);
> +
> +	if (ctrl1 & CTRL1_24HR)
> +		buff[2] = bin2bcd(tm->tm_hour);
> +	else
> +		buff[2] = rtc5t619_12hour_bin2bcd(tm->tm_hour);
> +
> +	buff[3] = bin2bcd(tm->tm_wday);
> +	buff[4] = bin2bcd(tm->tm_mday);
> +	buff[5] = bin2bcd(tm->tm_mon + 1);	/* system set 0-11 */
> +	buff[6] = bin2bcd(tm->tm_year - cent_flag * 100);
> +
> +	if (cent_flag)
> +		buff[5] |= MONTH_CENTFLAG;
> +
> +	err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS,
> +				buff, sizeof(buff));
> +	if (err < 0) {
> +		dev_err(dev, "failed to program new time: %d\n", err);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static int rc5t619_rtc_alarm_is_enabled(struct device *dev,  uint8_t *enabled)
> +{
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +	int err;
> +	unsigned int reg_data;
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &reg_data);
> +	if (err)
> +		return err;
> +
> +	if (reg_data & CTRL1_ALARM_ENABLED)
> +		*enabled = 1;
> +	else
> +		*enabled = 0;
> +
> +	return err;
> +}
> +
> +/* 0-disable, 1-enable */
> +static int rc5t619_rtc_alarm_enable(struct device *dev, unsigned int enabled)
> +{
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +
> +	return regmap_update_bits(rtc->rn5t618->regmap,
> +			RN5T618_RTC_CTRL1,
> +			CTRL1_ALARM_ENABLED,
> +			enabled ? CTRL1_ALARM_ENABLED : 0);
> +}
> +
> +static int rc5t619_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +	u8 buff[6];
> +	unsigned int buff_cent;
> +	int err;
> +	int cent_flag;
> +	unsigned int ctrl1;
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
> +	if (err)
> +		return err;
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_MONTH, &buff_cent);
> +	if (err < 0) {
> +		dev_err(dev, "failed to read time: %d\n", err);
> +		return err;
> +	}
> +
> +	if (buff_cent & MONTH_CENTFLAG)
> +		cent_flag = 1;
> +	else
> +		cent_flag = 0;
> +
> +	err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC,
> +			       buff, sizeof(buff));
> +	if (err)
> +		return err;
> +
> +	buff[3] = buff[3] & 0x3f;
> +
> +	alrm->time.tm_sec  = bcd2bin(buff[0]);
> +	alrm->time.tm_min  = bcd2bin(buff[1]);
> +
> +	if (ctrl1 & CTRL1_24HR)
> +		alrm->time.tm_hour = bcd2bin(buff[2]);
> +	else
> +		alrm->time.tm_hour = rtc5t619_12hour_bcd2bin(buff[2]);
> +
> +	alrm->time.tm_mday = bcd2bin(buff[3]);
> +	alrm->time.tm_mon  = bcd2bin(buff[4]) - 1;
> +	alrm->time.tm_year = bcd2bin(buff[5]) + 100 * cent_flag;
> +	alrm->enabled = !!(ctrl1 & CTRL1_ALARM_ENABLED);
> +	dev_dbg(dev, "read alarm: %ptR\n", &alrm->time);
> +
> +	return 0;
> +}
> +
> +static int rc5t619_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +	u8 buff[6];
> +	int err;
> +	int cent_flag;
> +	unsigned int ctrl1;
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
> +	if (err)
> +		return err;
> +
> +	err = rc5t619_rtc_alarm_enable(dev, 0);
> +	if (err < 0)
> +		return err;
> +
> +	if (rtc->irq == -1)
> +		return -EINVAL;
> +
> +	if (alrm->enabled == 0)
> +		return 0;
> +
> +	if (alrm->time.tm_year >= 100)
> +		cent_flag = 1;
> +	else
> +		cent_flag = 0;
> +
> +	alrm->time.tm_mon += 1;
> +	buff[0] = bin2bcd(alrm->time.tm_sec);
> +	buff[1] = bin2bcd(alrm->time.tm_min);
> +
> +	if (ctrl1 & CTRL1_24HR)
> +		buff[2] = bin2bcd(alrm->time.tm_hour);
> +	else
> +		buff[2] = rtc5t619_12hour_bin2bcd(alrm->time.tm_hour);
> +
> +	buff[3] = bin2bcd(alrm->time.tm_mday);
> +	buff[4] = bin2bcd(alrm->time.tm_mon);
> +	buff[5] = bin2bcd(alrm->time.tm_year - 100 * cent_flag);
> +	buff[3] |= MDAY_DAL_EXT;
> +
> +	err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC,
> +				buff, sizeof(buff));
> +	if (err < 0)
> +		return err;
> +
> +	return rc5t619_rtc_alarm_enable(dev, alrm->enabled);
> +}
> +
> +static const struct rtc_class_ops rc5t619_rtc_ops = {
> +	.read_time	= rc5t619_rtc_read_time,
> +	.set_time	= rc5t619_rtc_set_time,
> +	.set_alarm	= rc5t619_rtc_set_alarm,
> +	.read_alarm	= rc5t619_rtc_read_alarm,
> +	.alarm_irq_enable = rc5t619_rtc_alarm_enable,
> +};
> +
> +static int rc5t619_rtc_alarm_flag_clr(struct device *dev)
> +{
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +
> +	/* clear alarm-D status bits.*/
> +	return regmap_update_bits(rtc->rn5t618->regmap,
> +				RN5T618_RTC_CTRL2,
> +				CTRL2_ALARM_STATUS | CTRL2_CTC, 0);
> +}
> +
> +static irqreturn_t rc5t619_rtc_irq(int irq, void *data)
> +{
> +	struct device *dev = data;
> +	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
> +
> +	rc5t619_rtc_alarm_flag_clr(dev);
> +
> +	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
> +	return IRQ_HANDLED;
> +}
> +
> +static int rc5t619_rtc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
> +	struct rc5t619_rtc *rtc;
> +	unsigned int ctrl2;
> +	int err;
> +
> +	rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL);
> +	if (IS_ERR(rtc)) {
> +		err = PTR_ERR(rtc);
> +		return -ENOMEM;
> +	}
> +
> +	rtc->rn5t618 = rn5t618;
> +
> +	dev_set_drvdata(dev, rtc);
> +	rtc->irq = -1;
> +
> +	if (rn5t618->irq_data)
> +		rtc->irq = regmap_irq_get_virq(rn5t618->irq_data,
> +					       RN5T618_IRQ_RTC);
> +
> +	if (rtc->irq  < 0)
> +		rtc->irq = -1;
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
> +	if (err < 0)
> +		return err;
> +
> +	/* disable rtc periodic function */
> +	err = rc5t619_rtc_periodic_disable(&pdev->dev);
> +	if (err)
> +		return err;
> +
> +	if (ctrl2 & CTRL2_PON) {
> +		err = rc5t619_rtc_alarm_flag_clr(&pdev->dev);
> +		if (err)
> +			return err;
> +	}
> +
> +	rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
> +	if (IS_ERR(rtc->rtc)) {
> +		err = PTR_ERR(rtc->rtc);
> +		dev_err(dev, "RTC device register: err %d\n", err);
> +		return err;
> +	}
> +
> +	rtc->rtc->ops = &rc5t619_rtc_ops;
> +	rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
> +	rtc->rtc->range_max = RTC_TIMESTAMP_END_2099;
> +
> +	/* set interrupt and enable it */
> +	if (rtc->irq != -1) {
> +		err = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
> +						rc5t619_rtc_irq,
> +						IRQF_ONESHOT,
> +						"rtc-rc5t619",
> +						&pdev->dev);
> +		if (err < 0) {
> +			dev_err(&pdev->dev, "request IRQ:%d fail\n", rtc->irq);
> +			rtc->irq = -1;
> +
> +			err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
> +			if (err)
> +				return err;
> +
> +		} else {
> +			/* enable wake */
> +			device_init_wakeup(&pdev->dev, 1);
> +			enable_irq_wake(rtc->irq);
> +		}
> +	} else {
> +		/* system don't want to using alarm interrupt, so close it */
> +		err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
> +		if (err)
> +			return err;
> +
> +		dev_warn(&pdev->dev, "rc5t619 interrupt is disabled\n");
> +	}
> +
> +	return rtc_register_device(rtc->rtc);
> +}
> +
> +static struct platform_driver rc5t619_rtc_driver = {
> +	.driver	= {
> +		.name	= "rc5t619-rtc",
> +	},
> +	.probe	= rc5t619_rtc_probe,
> +};
> +
> +module_platform_driver(rc5t619_rtc_driver);
> +MODULE_ALIAS("platform:rc5t619-rtc");
> +MODULE_DESCRIPTION("RICOH RC5T619 RTC driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.20.1
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com