[rtc-linux] Re: [PATCH v3 1/8] rtc: ds3232: rename rtc-ds3232.c to rtc-ds3232-core.c for preparation

[Alexandre Belloni <alexandre.belloni@free-electrons.com>]

Hi,

I'm fine with the patches (apart from patch 7/8) but I'd like to request
one more change. Could actually support both the ds3232 and the ds3234
in the same file? That will nicely reduce the number of lines and remove
the need for an include.

For an example, you can have a look at sound/soc/codecs/wm8750.c

Thank you for your work!

On 01/03/2016 at 00:13:45 +0900, Akinobu Mita wrote :
> This is preparation for splitting into core module and i2c driver.
> This will make it a lot easier to review the real changes.
> 
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> Cc: Dennis Aberilla <denzzzhome@yahoo.com>
> ---
> * No changes since v1
> 
>  drivers/rtc/Makefile          |   1 +
>  drivers/rtc/rtc-ds3232-core.c | 517 ++++++++++++++++++++++++++++++++++++++++++
>  drivers/rtc/rtc-ds3232.c      | 517 ------------------------------------------
>  3 files changed, 518 insertions(+), 517 deletions(-)
>  create mode 100644 drivers/rtc/rtc-ds3232-core.c
>  delete mode 100644 drivers/rtc/rtc-ds3232.c
> 
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 62d61b2..0b8cb6c 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -59,6 +59,7 @@ obj-$(CONFIG_RTC_DRV_DS1685_FAMILY)	+= rtc-ds1685.o
>  obj-$(CONFIG_RTC_DRV_DS1742)	+= rtc-ds1742.o
>  obj-$(CONFIG_RTC_DRV_DS2404)	+= rtc-ds2404.o
>  obj-$(CONFIG_RTC_DRV_DS3232)	+= rtc-ds3232.o
> +rtc-ds3232-objs			:= rtc-ds3232-core.o
>  obj-$(CONFIG_RTC_DRV_DS3234)	+= rtc-ds3234.o
>  obj-$(CONFIG_RTC_DRV_EFI)	+= rtc-efi.o
>  obj-$(CONFIG_RTC_DRV_EM3027)	+= rtc-em3027.o
> diff --git a/drivers/rtc/rtc-ds3232-core.c b/drivers/rtc/rtc-ds3232-core.c
> new file mode 100644
> index 0000000..4e99ace
> --- /dev/null
> +++ b/drivers/rtc/rtc-ds3232-core.c
> @@ -0,0 +1,517 @@
> +/*
> + * RTC client/driver for the Maxim/Dallas DS3232 Real-Time Clock over I2C
> + *
> + * Copyright (C) 2009-2011 Freescale Semiconductor.
> + * Author: Jack Lan <jack.lan@freescale.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.
> + */
> +/*
> + * It would be more efficient to use i2c msgs/i2c_transfer directly but, as
> + * recommened in .../Documentation/i2c/writing-clients section
> + * "Sending and receiving", using SMBus level communication is preferred.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/i2c.h>
> +#include <linux/rtc.h>
> +#include <linux/bcd.h>
> +#include <linux/workqueue.h>
> +#include <linux/slab.h>
> +
> +#define DS3232_REG_SECONDS	0x00
> +#define DS3232_REG_MINUTES	0x01
> +#define DS3232_REG_HOURS	0x02
> +#define DS3232_REG_AMPM		0x02
> +#define DS3232_REG_DAY		0x03
> +#define DS3232_REG_DATE		0x04
> +#define DS3232_REG_MONTH	0x05
> +#define DS3232_REG_CENTURY	0x05
> +#define DS3232_REG_YEAR		0x06
> +#define DS3232_REG_ALARM1         0x07	/* Alarm 1 BASE */
> +#define DS3232_REG_ALARM2         0x0B	/* Alarm 2 BASE */
> +#define DS3232_REG_CR		0x0E	/* Control register */
> +#	define DS3232_REG_CR_nEOSC        0x80
> +#       define DS3232_REG_CR_INTCN        0x04
> +#       define DS3232_REG_CR_A2IE        0x02
> +#       define DS3232_REG_CR_A1IE        0x01
> +
> +#define DS3232_REG_SR	0x0F	/* control/status register */
> +#	define DS3232_REG_SR_OSF   0x80
> +#       define DS3232_REG_SR_BSY   0x04
> +#       define DS3232_REG_SR_A2F   0x02
> +#       define DS3232_REG_SR_A1F   0x01
> +
> +struct ds3232 {
> +	struct i2c_client *client;
> +	struct rtc_device *rtc;
> +	struct work_struct work;
> +
> +	/* The mutex protects alarm operations, and prevents a race
> +	 * between the enable_irq() in the workqueue and the free_irq()
> +	 * in the remove function.
> +	 */
> +	struct mutex mutex;
> +	bool suspended;
> +	int exiting;
> +};
> +
> +static struct i2c_driver ds3232_driver;
> +
> +static int ds3232_check_rtc_status(struct i2c_client *client)
> +{
> +	int ret = 0;
> +	int control, stat;
> +
> +	stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
> +	if (stat < 0)
> +		return stat;
> +
> +	if (stat & DS3232_REG_SR_OSF)
> +		dev_warn(&client->dev,
> +				"oscillator discontinuity flagged, "
> +				"time unreliable\n");
> +
> +	stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
> +
> +	ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* If the alarm is pending, clear it before requesting
> +	 * the interrupt, so an interrupt event isn't reported
> +	 * before everything is initialized.
> +	 */
> +
> +	control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> +	if (control < 0)
> +		return control;
> +
> +	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
> +	control |= DS3232_REG_CR_INTCN;
> +
> +	return i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
> +}
> +
> +static int ds3232_read_time(struct device *dev, struct rtc_time *time)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	int ret;
> +	u8 buf[7];
> +	unsigned int year, month, day, hour, minute, second;
> +	unsigned int week, twelve_hr, am_pm;
> +	unsigned int century, add_century = 0;
> +
> +	ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_SECONDS, 7, buf);
> +
> +	if (ret < 0)
> +		return ret;
> +	if (ret < 7)
> +		return -EIO;
> +
> +	second = buf[0];
> +	minute = buf[1];
> +	hour = buf[2];
> +	week = buf[3];
> +	day = buf[4];
> +	month = buf[5];
> +	year = buf[6];
> +
> +	/* Extract additional information for AM/PM and century */
> +
> +	twelve_hr = hour & 0x40;
> +	am_pm = hour & 0x20;
> +	century = month & 0x80;
> +
> +	/* Write to rtc_time structure */
> +
> +	time->tm_sec = bcd2bin(second);
> +	time->tm_min = bcd2bin(minute);
> +	if (twelve_hr) {
> +		/* Convert to 24 hr */
> +		if (am_pm)
> +			time->tm_hour = bcd2bin(hour & 0x1F) + 12;
> +		else
> +			time->tm_hour = bcd2bin(hour & 0x1F);
> +	} else {
> +		time->tm_hour = bcd2bin(hour);
> +	}
> +
> +	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
> +	time->tm_wday = bcd2bin(week) - 1;
> +	time->tm_mday = bcd2bin(day);
> +	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
> +	time->tm_mon = bcd2bin(month & 0x7F) - 1;
> +	if (century)
> +		add_century = 100;
> +
> +	time->tm_year = bcd2bin(year) + add_century;
> +
> +	return rtc_valid_tm(time);
> +}
> +
> +static int ds3232_set_time(struct device *dev, struct rtc_time *time)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	u8 buf[7];
> +
> +	/* Extract time from rtc_time and load into ds3232*/
> +
> +	buf[0] = bin2bcd(time->tm_sec);
> +	buf[1] = bin2bcd(time->tm_min);
> +	buf[2] = bin2bcd(time->tm_hour);
> +	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
> +	buf[3] = bin2bcd(time->tm_wday + 1);
> +	buf[4] = bin2bcd(time->tm_mday); /* Date */
> +	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
> +	buf[5] = bin2bcd(time->tm_mon + 1);
> +	if (time->tm_year >= 100) {
> +		buf[5] |= 0x80;
> +		buf[6] = bin2bcd(time->tm_year - 100);
> +	} else {
> +		buf[6] = bin2bcd(time->tm_year);
> +	}
> +
> +	return i2c_smbus_write_i2c_block_data(client,
> +					      DS3232_REG_SECONDS, 7, buf);
> +}
> +
> +/*
> + * DS3232 has two alarm, we only use alarm1
> + * According to linux specification, only support one-shot alarm
> + * no periodic alarm mode
> + */
> +static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> +	int control, stat;
> +	int ret;
> +	u8 buf[4];
> +
> +	mutex_lock(&ds3232->mutex);
> +
> +	ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
> +	if (ret < 0)
> +		goto out;
> +	stat = ret;
> +	ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> +	if (ret < 0)
> +		goto out;
> +	control = ret;
> +	ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
> +	if (ret < 0)
> +		goto out;
> +
> +	alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
> +	alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
> +	alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
> +	alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
> +
> +	alarm->time.tm_mon = -1;
> +	alarm->time.tm_year = -1;
> +	alarm->time.tm_wday = -1;
> +	alarm->time.tm_yday = -1;
> +	alarm->time.tm_isdst = -1;
> +
> +	alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
> +	alarm->pending = !!(stat & DS3232_REG_SR_A1F);
> +
> +	ret = 0;
> +out:
> +	mutex_unlock(&ds3232->mutex);
> +	return ret;
> +}
> +
> +/*
> + * linux rtc-module does not support wday alarm
> + * and only 24h time mode supported indeed
> + */
> +static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> +	int control, stat;
> +	int ret;
> +	u8 buf[4];
> +
> +	if (client->irq <= 0)
> +		return -EINVAL;
> +
> +	mutex_lock(&ds3232->mutex);
> +
> +	buf[0] = bin2bcd(alarm->time.tm_sec);
> +	buf[1] = bin2bcd(alarm->time.tm_min);
> +	buf[2] = bin2bcd(alarm->time.tm_hour);
> +	buf[3] = bin2bcd(alarm->time.tm_mday);
> +
> +	/* clear alarm interrupt enable bit */
> +	ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> +	if (ret < 0)
> +		goto out;
> +	control = ret;
> +	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
> +	ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
> +	if (ret < 0)
> +		goto out;
> +
> +	/* clear any pending alarm flag */
> +	ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
> +	if (ret < 0)
> +		goto out;
> +	stat = ret;
> +	stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
> +	ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
> +	if (ret < 0)
> +		goto out;
> +
> +	ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
> +
> +	if (alarm->enabled) {
> +		control |= DS3232_REG_CR_A1IE;
> +		ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
> +	}
> +out:
> +	mutex_unlock(&ds3232->mutex);
> +	return ret;
> +}
> +
> +static void ds3232_update_alarm(struct i2c_client *client)
> +{
> +	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> +	int control;
> +	int ret;
> +	u8 buf[4];
> +
> +	mutex_lock(&ds3232->mutex);
> +
> +	ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
> +	if (ret < 0)
> +		goto unlock;
> +
> +	buf[0] = bcd2bin(buf[0]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
> +								0x80 : buf[0];
> +	buf[1] = bcd2bin(buf[1]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
> +								0x80 : buf[1];
> +	buf[2] = bcd2bin(buf[2]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
> +								0x80 : buf[2];
> +	buf[3] = bcd2bin(buf[3]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
> +								0x80 : buf[3];
> +
> +	ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
> +	if (ret < 0)
> +		goto unlock;
> +
> +	control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> +	if (control < 0)
> +		goto unlock;
> +
> +	if (ds3232->rtc->irq_data & (RTC_AF | RTC_UF))
> +		/* enable alarm1 interrupt */
> +		control |= DS3232_REG_CR_A1IE;
> +	else
> +		/* disable alarm1 interrupt */
> +		control &= ~(DS3232_REG_CR_A1IE);
> +	i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
> +
> +unlock:
> +	mutex_unlock(&ds3232->mutex);
> +}
> +
> +static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> +
> +	if (client->irq <= 0)
> +		return -EINVAL;
> +
> +	if (enabled)
> +		ds3232->rtc->irq_data |= RTC_AF;
> +	else
> +		ds3232->rtc->irq_data &= ~RTC_AF;
> +
> +	ds3232_update_alarm(client);
> +	return 0;
> +}
> +
> +static irqreturn_t ds3232_irq(int irq, void *dev_id)
> +{
> +	struct i2c_client *client = dev_id;
> +	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> +
> +	disable_irq_nosync(irq);
> +
> +	/*
> +	 * If rtc as a wakeup source, can't schedule the work
> +	 * at system resume flow, because at this time the i2c bus
> +	 * has not been resumed.
> +	 */
> +	if (!ds3232->suspended)
> +		schedule_work(&ds3232->work);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void ds3232_work(struct work_struct *work)
> +{
> +	struct ds3232 *ds3232 = container_of(work, struct ds3232, work);
> +	struct i2c_client *client = ds3232->client;
> +	int stat, control;
> +
> +	mutex_lock(&ds3232->mutex);
> +
> +	stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
> +	if (stat < 0)
> +		goto unlock;
> +
> +	if (stat & DS3232_REG_SR_A1F) {
> +		control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> +		if (control < 0) {
> +			pr_warn("Read Control Register error - Disable IRQ%d\n",
> +				client->irq);
> +		} else {
> +			/* disable alarm1 interrupt */
> +			control &= ~(DS3232_REG_CR_A1IE);
> +			i2c_smbus_write_byte_data(client, DS3232_REG_CR,
> +						control);
> +
> +			/* clear the alarm pend flag */
> +			stat &= ~DS3232_REG_SR_A1F;
> +			i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
> +
> +			rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
> +
> +			if (!ds3232->exiting)
> +				enable_irq(client->irq);
> +		}
> +	}
> +
> +unlock:
> +	mutex_unlock(&ds3232->mutex);
> +}
> +
> +static const struct rtc_class_ops ds3232_rtc_ops = {
> +	.read_time = ds3232_read_time,
> +	.set_time = ds3232_set_time,
> +	.read_alarm = ds3232_read_alarm,
> +	.set_alarm = ds3232_set_alarm,
> +	.alarm_irq_enable = ds3232_alarm_irq_enable,
> +};
> +
> +static int ds3232_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct ds3232 *ds3232;
> +	int ret;
> +
> +	ds3232 = devm_kzalloc(&client->dev, sizeof(struct ds3232), GFP_KERNEL);
> +	if (!ds3232)
> +		return -ENOMEM;
> +
> +	ds3232->client = client;
> +	i2c_set_clientdata(client, ds3232);
> +
> +	INIT_WORK(&ds3232->work, ds3232_work);
> +	mutex_init(&ds3232->mutex);
> +
> +	ret = ds3232_check_rtc_status(client);
> +	if (ret)
> +		return ret;
> +
> +	if (client->irq > 0) {
> +		ret = devm_request_irq(&client->dev, client->irq, ds3232_irq,
> +				       IRQF_SHARED, "ds3232", client);
> +		if (ret) {
> +			dev_err(&client->dev, "unable to request IRQ\n");
> +		}
> +		device_init_wakeup(&client->dev, 1);
> +	}
> +	ds3232->rtc = devm_rtc_device_register(&client->dev, client->name,
> +					  &ds3232_rtc_ops, THIS_MODULE);
> +	return PTR_ERR_OR_ZERO(ds3232->rtc);
> +}
> +
> +static int ds3232_remove(struct i2c_client *client)
> +{
> +	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> +
> +	if (client->irq > 0) {
> +		mutex_lock(&ds3232->mutex);
> +		ds3232->exiting = 1;
> +		mutex_unlock(&ds3232->mutex);
> +
> +		devm_free_irq(&client->dev, client->irq, client);
> +		cancel_work_sync(&ds3232->work);
> +	}
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int ds3232_suspend(struct device *dev)
> +{
> +	struct ds3232 *ds3232 = dev_get_drvdata(dev);
> +	struct i2c_client *client = to_i2c_client(dev);
> +
> +	if (device_can_wakeup(dev)) {
> +		ds3232->suspended = true;
> +		if (irq_set_irq_wake(client->irq, 1)) {
> +			dev_warn_once(dev, "Cannot set wakeup source\n");
> +			ds3232->suspended = false;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int ds3232_resume(struct device *dev)
> +{
> +	struct ds3232 *ds3232 = dev_get_drvdata(dev);
> +	struct i2c_client *client = to_i2c_client(dev);
> +
> +	if (ds3232->suspended) {
> +		ds3232->suspended = false;
> +
> +		/* Clear the hardware alarm pend flag */
> +		schedule_work(&ds3232->work);
> +
> +		irq_set_irq_wake(client->irq, 0);
> +	}
> +
> +	return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops ds3232_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
> +};
> +
> +static const struct i2c_device_id ds3232_id[] = {
> +	{ "ds3232", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ds3232_id);
> +
> +static struct i2c_driver ds3232_driver = {
> +	.driver = {
> +		.name = "rtc-ds3232",
> +		.pm	= &ds3232_pm_ops,
> +	},
> +	.probe = ds3232_probe,
> +	.remove = ds3232_remove,
> +	.id_table = ds3232_id,
> +};
> +
> +module_i2c_driver(ds3232_driver);
> +
> +MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
> +MODULE_DESCRIPTION("Maxim/Dallas DS3232 RTC Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
> deleted file mode 100644
> index 4e99ace..0000000
> --- a/drivers/rtc/rtc-ds3232.c
> +++ /dev/null
> @@ -1,517 +0,0 @@
> -/*
> - * RTC client/driver for the Maxim/Dallas DS3232 Real-Time Clock over I2C
> - *
> - * Copyright (C) 2009-2011 Freescale Semiconductor.
> - * Author: Jack Lan <jack.lan@freescale.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.
> - */
> -/*
> - * It would be more efficient to use i2c msgs/i2c_transfer directly but, as
> - * recommened in .../Documentation/i2c/writing-clients section
> - * "Sending and receiving", using SMBus level communication is preferred.
> - */
> -
> -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> -
> -#include <linux/kernel.h>
> -#include <linux/module.h>
> -#include <linux/interrupt.h>
> -#include <linux/i2c.h>
> -#include <linux/rtc.h>
> -#include <linux/bcd.h>
> -#include <linux/workqueue.h>
> -#include <linux/slab.h>
> -
> -#define DS3232_REG_SECONDS	0x00
> -#define DS3232_REG_MINUTES	0x01
> -#define DS3232_REG_HOURS	0x02
> -#define DS3232_REG_AMPM		0x02
> -#define DS3232_REG_DAY		0x03
> -#define DS3232_REG_DATE		0x04
> -#define DS3232_REG_MONTH	0x05
> -#define DS3232_REG_CENTURY	0x05
> -#define DS3232_REG_YEAR		0x06
> -#define DS3232_REG_ALARM1         0x07	/* Alarm 1 BASE */
> -#define DS3232_REG_ALARM2         0x0B	/* Alarm 2 BASE */
> -#define DS3232_REG_CR		0x0E	/* Control register */
> -#	define DS3232_REG_CR_nEOSC        0x80
> -#       define DS3232_REG_CR_INTCN        0x04
> -#       define DS3232_REG_CR_A2IE        0x02
> -#       define DS3232_REG_CR_A1IE        0x01
> -
> -#define DS3232_REG_SR	0x0F	/* control/status register */
> -#	define DS3232_REG_SR_OSF   0x80
> -#       define DS3232_REG_SR_BSY   0x04
> -#       define DS3232_REG_SR_A2F   0x02
> -#       define DS3232_REG_SR_A1F   0x01
> -
> -struct ds3232 {
> -	struct i2c_client *client;
> -	struct rtc_device *rtc;
> -	struct work_struct work;
> -
> -	/* The mutex protects alarm operations, and prevents a race
> -	 * between the enable_irq() in the workqueue and the free_irq()
> -	 * in the remove function.
> -	 */
> -	struct mutex mutex;
> -	bool suspended;
> -	int exiting;
> -};
> -
> -static struct i2c_driver ds3232_driver;
> -
> -static int ds3232_check_rtc_status(struct i2c_client *client)
> -{
> -	int ret = 0;
> -	int control, stat;
> -
> -	stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
> -	if (stat < 0)
> -		return stat;
> -
> -	if (stat & DS3232_REG_SR_OSF)
> -		dev_warn(&client->dev,
> -				"oscillator discontinuity flagged, "
> -				"time unreliable\n");
> -
> -	stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
> -
> -	ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
> -	if (ret < 0)
> -		return ret;
> -
> -	/* If the alarm is pending, clear it before requesting
> -	 * the interrupt, so an interrupt event isn't reported
> -	 * before everything is initialized.
> -	 */
> -
> -	control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> -	if (control < 0)
> -		return control;
> -
> -	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
> -	control |= DS3232_REG_CR_INTCN;
> -
> -	return i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
> -}
> -
> -static int ds3232_read_time(struct device *dev, struct rtc_time *time)
> -{
> -	struct i2c_client *client = to_i2c_client(dev);
> -	int ret;
> -	u8 buf[7];
> -	unsigned int year, month, day, hour, minute, second;
> -	unsigned int week, twelve_hr, am_pm;
> -	unsigned int century, add_century = 0;
> -
> -	ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_SECONDS, 7, buf);
> -
> -	if (ret < 0)
> -		return ret;
> -	if (ret < 7)
> -		return -EIO;
> -
> -	second = buf[0];
> -	minute = buf[1];
> -	hour = buf[2];
> -	week = buf[3];
> -	day = buf[4];
> -	month = buf[5];
> -	year = buf[6];
> -
> -	/* Extract additional information for AM/PM and century */
> -
> -	twelve_hr = hour & 0x40;
> -	am_pm = hour & 0x20;
> -	century = month & 0x80;
> -
> -	/* Write to rtc_time structure */
> -
> -	time->tm_sec = bcd2bin(second);
> -	time->tm_min = bcd2bin(minute);
> -	if (twelve_hr) {
> -		/* Convert to 24 hr */
> -		if (am_pm)
> -			time->tm_hour = bcd2bin(hour & 0x1F) + 12;
> -		else
> -			time->tm_hour = bcd2bin(hour & 0x1F);
> -	} else {
> -		time->tm_hour = bcd2bin(hour);
> -	}
> -
> -	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
> -	time->tm_wday = bcd2bin(week) - 1;
> -	time->tm_mday = bcd2bin(day);
> -	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
> -	time->tm_mon = bcd2bin(month & 0x7F) - 1;
> -	if (century)
> -		add_century = 100;
> -
> -	time->tm_year = bcd2bin(year) + add_century;
> -
> -	return rtc_valid_tm(time);
> -}
> -
> -static int ds3232_set_time(struct device *dev, struct rtc_time *time)
> -{
> -	struct i2c_client *client = to_i2c_client(dev);
> -	u8 buf[7];
> -
> -	/* Extract time from rtc_time and load into ds3232*/
> -
> -	buf[0] = bin2bcd(time->tm_sec);
> -	buf[1] = bin2bcd(time->tm_min);
> -	buf[2] = bin2bcd(time->tm_hour);
> -	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
> -	buf[3] = bin2bcd(time->tm_wday + 1);
> -	buf[4] = bin2bcd(time->tm_mday); /* Date */
> -	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
> -	buf[5] = bin2bcd(time->tm_mon + 1);
> -	if (time->tm_year >= 100) {
> -		buf[5] |= 0x80;
> -		buf[6] = bin2bcd(time->tm_year - 100);
> -	} else {
> -		buf[6] = bin2bcd(time->tm_year);
> -	}
> -
> -	return i2c_smbus_write_i2c_block_data(client,
> -					      DS3232_REG_SECONDS, 7, buf);
> -}
> -
> -/*
> - * DS3232 has two alarm, we only use alarm1
> - * According to linux specification, only support one-shot alarm
> - * no periodic alarm mode
> - */
> -static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
> -{
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> -	int control, stat;
> -	int ret;
> -	u8 buf[4];
> -
> -	mutex_lock(&ds3232->mutex);
> -
> -	ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
> -	if (ret < 0)
> -		goto out;
> -	stat = ret;
> -	ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> -	if (ret < 0)
> -		goto out;
> -	control = ret;
> -	ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
> -	if (ret < 0)
> -		goto out;
> -
> -	alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
> -	alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
> -	alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
> -	alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
> -
> -	alarm->time.tm_mon = -1;
> -	alarm->time.tm_year = -1;
> -	alarm->time.tm_wday = -1;
> -	alarm->time.tm_yday = -1;
> -	alarm->time.tm_isdst = -1;
> -
> -	alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
> -	alarm->pending = !!(stat & DS3232_REG_SR_A1F);
> -
> -	ret = 0;
> -out:
> -	mutex_unlock(&ds3232->mutex);
> -	return ret;
> -}
> -
> -/*
> - * linux rtc-module does not support wday alarm
> - * and only 24h time mode supported indeed
> - */
> -static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
> -{
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> -	int control, stat;
> -	int ret;
> -	u8 buf[4];
> -
> -	if (client->irq <= 0)
> -		return -EINVAL;
> -
> -	mutex_lock(&ds3232->mutex);
> -
> -	buf[0] = bin2bcd(alarm->time.tm_sec);
> -	buf[1] = bin2bcd(alarm->time.tm_min);
> -	buf[2] = bin2bcd(alarm->time.tm_hour);
> -	buf[3] = bin2bcd(alarm->time.tm_mday);
> -
> -	/* clear alarm interrupt enable bit */
> -	ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> -	if (ret < 0)
> -		goto out;
> -	control = ret;
> -	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
> -	ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
> -	if (ret < 0)
> -		goto out;
> -
> -	/* clear any pending alarm flag */
> -	ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
> -	if (ret < 0)
> -		goto out;
> -	stat = ret;
> -	stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
> -	ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
> -	if (ret < 0)
> -		goto out;
> -
> -	ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
> -
> -	if (alarm->enabled) {
> -		control |= DS3232_REG_CR_A1IE;
> -		ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
> -	}
> -out:
> -	mutex_unlock(&ds3232->mutex);
> -	return ret;
> -}
> -
> -static void ds3232_update_alarm(struct i2c_client *client)
> -{
> -	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> -	int control;
> -	int ret;
> -	u8 buf[4];
> -
> -	mutex_lock(&ds3232->mutex);
> -
> -	ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
> -	if (ret < 0)
> -		goto unlock;
> -
> -	buf[0] = bcd2bin(buf[0]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
> -								0x80 : buf[0];
> -	buf[1] = bcd2bin(buf[1]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
> -								0x80 : buf[1];
> -	buf[2] = bcd2bin(buf[2]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
> -								0x80 : buf[2];
> -	buf[3] = bcd2bin(buf[3]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ?
> -								0x80 : buf[3];
> -
> -	ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf);
> -	if (ret < 0)
> -		goto unlock;
> -
> -	control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> -	if (control < 0)
> -		goto unlock;
> -
> -	if (ds3232->rtc->irq_data & (RTC_AF | RTC_UF))
> -		/* enable alarm1 interrupt */
> -		control |= DS3232_REG_CR_A1IE;
> -	else
> -		/* disable alarm1 interrupt */
> -		control &= ~(DS3232_REG_CR_A1IE);
> -	i2c_smbus_write_byte_data(client, DS3232_REG_CR, control);
> -
> -unlock:
> -	mutex_unlock(&ds3232->mutex);
> -}
> -
> -static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
> -{
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> -
> -	if (client->irq <= 0)
> -		return -EINVAL;
> -
> -	if (enabled)
> -		ds3232->rtc->irq_data |= RTC_AF;
> -	else
> -		ds3232->rtc->irq_data &= ~RTC_AF;
> -
> -	ds3232_update_alarm(client);
> -	return 0;
> -}
> -
> -static irqreturn_t ds3232_irq(int irq, void *dev_id)
> -{
> -	struct i2c_client *client = dev_id;
> -	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> -
> -	disable_irq_nosync(irq);
> -
> -	/*
> -	 * If rtc as a wakeup source, can't schedule the work
> -	 * at system resume flow, because at this time the i2c bus
> -	 * has not been resumed.
> -	 */
> -	if (!ds3232->suspended)
> -		schedule_work(&ds3232->work);
> -
> -	return IRQ_HANDLED;
> -}
> -
> -static void ds3232_work(struct work_struct *work)
> -{
> -	struct ds3232 *ds3232 = container_of(work, struct ds3232, work);
> -	struct i2c_client *client = ds3232->client;
> -	int stat, control;
> -
> -	mutex_lock(&ds3232->mutex);
> -
> -	stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
> -	if (stat < 0)
> -		goto unlock;
> -
> -	if (stat & DS3232_REG_SR_A1F) {
> -		control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
> -		if (control < 0) {
> -			pr_warn("Read Control Register error - Disable IRQ%d\n",
> -				client->irq);
> -		} else {
> -			/* disable alarm1 interrupt */
> -			control &= ~(DS3232_REG_CR_A1IE);
> -			i2c_smbus_write_byte_data(client, DS3232_REG_CR,
> -						control);
> -
> -			/* clear the alarm pend flag */
> -			stat &= ~DS3232_REG_SR_A1F;
> -			i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
> -
> -			rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
> -
> -			if (!ds3232->exiting)
> -				enable_irq(client->irq);
> -		}
> -	}
> -
> -unlock:
> -	mutex_unlock(&ds3232->mutex);
> -}
> -
> -static const struct rtc_class_ops ds3232_rtc_ops = {
> -	.read_time = ds3232_read_time,
> -	.set_time = ds3232_set_time,
> -	.read_alarm = ds3232_read_alarm,
> -	.set_alarm = ds3232_set_alarm,
> -	.alarm_irq_enable = ds3232_alarm_irq_enable,
> -};
> -
> -static int ds3232_probe(struct i2c_client *client,
> -			const struct i2c_device_id *id)
> -{
> -	struct ds3232 *ds3232;
> -	int ret;
> -
> -	ds3232 = devm_kzalloc(&client->dev, sizeof(struct ds3232), GFP_KERNEL);
> -	if (!ds3232)
> -		return -ENOMEM;
> -
> -	ds3232->client = client;
> -	i2c_set_clientdata(client, ds3232);
> -
> -	INIT_WORK(&ds3232->work, ds3232_work);
> -	mutex_init(&ds3232->mutex);
> -
> -	ret = ds3232_check_rtc_status(client);
> -	if (ret)
> -		return ret;
> -
> -	if (client->irq > 0) {
> -		ret = devm_request_irq(&client->dev, client->irq, ds3232_irq,
> -				       IRQF_SHARED, "ds3232", client);
> -		if (ret) {
> -			dev_err(&client->dev, "unable to request IRQ\n");
> -		}
> -		device_init_wakeup(&client->dev, 1);
> -	}
> -	ds3232->rtc = devm_rtc_device_register(&client->dev, client->name,
> -					  &ds3232_rtc_ops, THIS_MODULE);
> -	return PTR_ERR_OR_ZERO(ds3232->rtc);
> -}
> -
> -static int ds3232_remove(struct i2c_client *client)
> -{
> -	struct ds3232 *ds3232 = i2c_get_clientdata(client);
> -
> -	if (client->irq > 0) {
> -		mutex_lock(&ds3232->mutex);
> -		ds3232->exiting = 1;
> -		mutex_unlock(&ds3232->mutex);
> -
> -		devm_free_irq(&client->dev, client->irq, client);
> -		cancel_work_sync(&ds3232->work);
> -	}
> -
> -	return 0;
> -}
> -
> -#ifdef CONFIG_PM_SLEEP
> -static int ds3232_suspend(struct device *dev)
> -{
> -	struct ds3232 *ds3232 = dev_get_drvdata(dev);
> -	struct i2c_client *client = to_i2c_client(dev);
> -
> -	if (device_can_wakeup(dev)) {
> -		ds3232->suspended = true;
> -		if (irq_set_irq_wake(client->irq, 1)) {
> -			dev_warn_once(dev, "Cannot set wakeup source\n");
> -			ds3232->suspended = false;
> -		}
> -	}
> -
> -	return 0;
> -}
> -
> -static int ds3232_resume(struct device *dev)
> -{
> -	struct ds3232 *ds3232 = dev_get_drvdata(dev);
> -	struct i2c_client *client = to_i2c_client(dev);
> -
> -	if (ds3232->suspended) {
> -		ds3232->suspended = false;
> -
> -		/* Clear the hardware alarm pend flag */
> -		schedule_work(&ds3232->work);
> -
> -		irq_set_irq_wake(client->irq, 0);
> -	}
> -
> -	return 0;
> -}
> -#endif
> -
> -static const struct dev_pm_ops ds3232_pm_ops = {
> -	SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
> -};
> -
> -static const struct i2c_device_id ds3232_id[] = {
> -	{ "ds3232", 0 },
> -	{ }
> -};
> -MODULE_DEVICE_TABLE(i2c, ds3232_id);
> -
> -static struct i2c_driver ds3232_driver = {
> -	.driver = {
> -		.name = "rtc-ds3232",
> -		.pm	= &ds3232_pm_ops,
> -	},
> -	.probe = ds3232_probe,
> -	.remove = ds3232_remove,
> -	.id_table = ds3232_id,
> -};
> -
> -module_i2c_driver(ds3232_driver);
> -
> -MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
> -MODULE_DESCRIPTION("Maxim/Dallas DS3232 RTC Driver");
> -MODULE_LICENSE("GPL");
> -- 
> 2.5.0
> 

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

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