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.
> 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?
> +
> +static int __devinit ds3232_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct ds3232 *ds3232;
> + int ret;
> +
> + ds3232 = kzalloc(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)
> + goto out_free;
> +
> + ds3232->rtc = rtc_device_register(client->name, &client->dev,
> + &ds3232_rtc_ops, THIS_MODULE);
> + if (IS_ERR(ds3232->rtc)) {
> + ret = PTR_ERR(ds3232->rtc);
> + dev_err(&client->dev, "unable to register the class
> device\n");
> + goto out_irq;
> + }
> +
> + if (client->irq >= 0) {
> + ret = request_irq(client->irq, ds3232_irq, 0,
> + "ds3232", client);
> + if (ret) {
> + dev_err(&client->dev, "unable to request IRQ\n");
> + goto out_free;
> + }
> + }
> +
> + return 0;
> +
> +out_irq:
> + if (client->irq >= 0)
> + free_irq(client->irq, client);
> +
> +out_free:
> + i2c_set_clientdata(client, NULL);
> + kfree(ds3232);
> + return ret;
> +}
> +
> +static int __devexit 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);
> +
> + free_irq(client->irq, client);
> + flush_scheduled_work();
> + }
> +
> + rtc_device_unregister(ds3232->rtc);
> + i2c_set_clientdata(client, NULL);
> + kfree(ds3232);
> + return 0;
> +}
> +
> +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",
> + .owner = THIS_MODULE,
> + },
> + .probe = ds3232_probe,
> + .remove = __devexit_p(ds3232_remove),
> + .id_table = ds3232_id,
> +};
> +
> +static int __init ds3232_init(void)
> +{
> + return i2c_add_driver(&ds3232_driver);
> +}
> +
> +static void __exit ds3232_exit(void)
> +{
> + i2c_del_driver(&ds3232_driver);
> +}
> +
> +module_init(ds3232_init);
> +module_exit(ds3232_exit);
> +
> +MODULE_AUTHOR("Srikanth Srinivasan <srikanth.sriniva...@freescale.com>");
> +MODULE_DESCRIPTION("Maxim/Dallas DS3232 RTC Driver");
> +MODULE_LICENSE("GPL");
> --
> 1.5.6.5
>
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