2010/7/12 Tiefei zang <tiefei.z...@gmail.com>:
> On Mon, Jul 12, 2010 at 3:08 PM, Wan ZongShun <mcuos....@gmail.com> wrote:
>> 2010/7/12 Roy Zang <tie-fei.z...@freescale.com>:
>>> This patch adds the driver for RTC chip DS3232 via I2C bus.
>>>
>>
>> I noted this patch is the second version, maybe you can describe which
>> modifications you have done here.
>> and add [PATCH v2] to mail subject.
> I do not think the modification comparing previous version should go
> into the commit message.
> I buy in your comments in original version patch and update:
> 1. add rtc_valid_tm to check return value.
> 2. remove ioctl function, which do not used and tested.
> 3. add __devinit for ds3232 probe
> 4. put request irq after driver registration.
>
Okay.
Which git tree do you want to merge your patch?
>>
>>> Signed-off-by: Mingkai Hu <mingkai...@freescale.com>
>>> Signed-off-by: Jingchang Lu <b22...@freescale.com>
>>> Signed-off-by: Srikanth Srinivasan <srikanth.sriniva...@freescale.com>
>>> Signed-off-by: Roy Zang <tie-fei.z...@freescale.com>
>>> ---
>>> Tested on MPC8536DS and P4080DS board
>>>
>>> drivers/rtc/Kconfig | 11 ++
>>> drivers/rtc/Makefile | 1 +
>>> drivers/rtc/rtc-ds3232.c | 427
>>> ++++++++++++++++++++++++++++++++++++++++++++++
>>> 3 files changed, 439 insertions(+), 0 deletions(-)
>>> create mode 100644 drivers/rtc/rtc-ds3232.c
>>>
>>> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
>>> index 6a13037..13c2fdb 100644
>>> --- a/drivers/rtc/Kconfig
>>> +++ b/drivers/rtc/Kconfig
>>> @@ -166,6 +166,17 @@ config RTC_DRV_DS1672
>>> This driver can also be built as a module. If so, the module
>>> will be called rtc-ds1672.
>>>
>>> +config RTC_DRV_DS3232
>>> + tristate "Dallas/Maxim DS3232"
>>> + depends on RTC_CLASS && I2C
>>> + help
>>> + If you say yes here you get support for Dallas Semiconductor
>>> + DS3232 real-time clock chips. If an interrupt is associated
>>> + with the device, the alarm functionality is supported.
>>> +
>>> + This driver can also be built as a module. If so, the module
>>> + will be called rtc-ds3232.
>>> +
>>> config RTC_DRV_MAX6900
>>> tristate "Maxim MAX6900"
>>> help
>>> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
>>> index 44ef194..0af190c 100644
>>> --- a/drivers/rtc/Makefile
>>> +++ b/drivers/rtc/Makefile
>>> @@ -39,6 +39,7 @@ obj-$(CONFIG_RTC_DRV_DS1511) += rtc-ds1511.o
>>> obj-$(CONFIG_RTC_DRV_DS1553) += rtc-ds1553.o
>>> obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o
>>> obj-$(CONFIG_RTC_DRV_DS1742) += rtc-ds1742.o
>>> +obj-$(CONFIG_RTC_DRV_DS3232) += rtc-ds3232.o
>>> obj-$(CONFIG_RTC_DRV_DS3234) += rtc-ds3234.o
>>> obj-$(CONFIG_RTC_DRV_EFI) += rtc-efi.o
>>> obj-$(CONFIG_RTC_DRV_EP93XX) += rtc-ep93xx.o
>>> diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
>>> new file mode 100644
>>> index 0000000..e36ec1c
>>> --- /dev/null
>>> +++ b/drivers/rtc/rtc-ds3232.c
>>> @@ -0,0 +1,427 @@
>>> +/*
>>> + * RTC client/driver for the Maxim/Dallas DS3232 Real-Time Clock over I2C
>>> + *
>>> + * Copyright (C) 2009-2010 Freescale Semiconductor.
>>> + *
>>> + * 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.
>>> + */
>>> +
>>> +#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;
>>> + 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);
>>> + }
>>> +
>>> + time->tm_wday = bcd2bin(week);
>>> + time->tm_mday = bcd2bin(day);
>>> + time->tm_mon = bcd2bin(month & 0x7F);
>>> + 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);
>>> + buf[3] = bin2bcd(time->tm_wday); /* Day of the week */
>>> + buf[4] = bin2bcd(time->tm_mday); /* Date */
>>> + buf[5] = bin2bcd(time->tm_mon);
>>> + 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 = 0;
>>> + u8 buf[4];
>>> +
>>> + mutex_lock(&ds3232->mutex);
>>> + stat = ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
>>> + if (stat < 0)
>>> + goto out;
>>> +
>>> + control = ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
>>> + if (control < 0)
>>> + goto out;
>>> +
>>> + 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);
>>> +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 = 0;
>>> + 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 = control = i2c_smbus_read_byte_data(client, DS3232_REG_CR);
>>> + if (ret < 0)
>>> + goto out;
>>> + 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 */
>>> + stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR);
>>> + if (stat < 0)
>>> + return stat;
>>> +
>>> + stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
>>> +
>>> + ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + 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 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);
>>> + 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)
>>> + goto out;
>>> + /* 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);
>>> + }
>>> +
>>> +out:
>>> + 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,
>>> +};
>>
>> I sew that you have discarded the .ioctl function, which is used to
>> enable/disable the alarm irq in previous driver patch.
>> but,at the same time, you didnot implement .alarm_irq_enable function
>> , so is there no need to enable or disable the alarm irq bit in
>> current version patch?
> Right. This is not needed in current patch. Alarm is not used and tested.
> Thanks.
> Roy
>
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