Patchwork [v0] RTC driver(Linux) for PT7C4338 chip.

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Submitter Priyanka Jain
Date Oct. 25, 2010, 8:08 a.m.
Message ID <1287994138-31771-1-git-send-email-Priyanka.Jain@freescale.com>
Download mbox | patch
Permalink /patch/69077/
State Superseded
Headers show

Comments

Priyanka Jain - Oct. 25, 2010, 8:08 a.m.
PT7C4338 chip is manufactured by Pericom Technology Inc.
It is a serial real-time clock which provides:
1)Low-power clock/calendar.
2)Programmable square-wave output.
It has 56 bytes of nonvolatile RAM.

Freescale P1010RDB uses PT7C4338 as RTC.

Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
---
 Based of unified git(next branch) for P1010 RDB.
 drivers/rtc/Kconfig        |    9 ++
 drivers/rtc/Makefile       |    1 +
 drivers/rtc/rtc-pt7c4338.c |  215 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 225 insertions(+), 0 deletions(-)
 create mode 100644 drivers/rtc/rtc-pt7c4338.c
Kumar Gala - Oct. 26, 2010, 7:52 a.m.
On Oct 25, 2010, at 3:08 AM, Priyanka Jain wrote:

> PT7C4338 chip is manufactured by Pericom Technology Inc.
> It is a serial real-time clock which provides:
> 1)Low-power clock/calendar.
> 2)Programmable square-wave output.
> It has 56 bytes of nonvolatile RAM.
> 
> Freescale P1010RDB uses PT7C4338 as RTC.

This line shouldn't be in the commit message

> 
> Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
> ---
> Based of unified git(next branch) for P1010 RDB.
> drivers/rtc/Kconfig        |    9 ++
> drivers/rtc/Makefile       |    1 +
> drivers/rtc/rtc-pt7c4338.c |  215 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 225 insertions(+), 0 deletions(-)
> create mode 100644 drivers/rtc/rtc-pt7c4338.c

This should be CC'd to the RTC list and maintainer.

- k

Patch

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 10ba12c..6ff0901 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -324,6 +324,15 @@  config RTC_DRV_RX8025
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-rx8025.
 
+config RTC_DRV_PT7C4338
+	tristate "Pericom Technology Inc. PT7C4338 RTC"
+	help
+	  If you say yes here you get support for the Pericom Technology
+	  Inc. PT7C4338 RTC chip.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-pt7c4338.
+
 endif # I2C
 
 comment "SPI RTC drivers"
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 5adbba7..4014607 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -70,6 +70,7 @@  obj-$(CONFIG_RTC_DRV_PCF50633)	+= rtc-pcf50633.o
 obj-$(CONFIG_RTC_DRV_PL030)	+= rtc-pl030.o
 obj-$(CONFIG_RTC_DRV_PL031)	+= rtc-pl031.o
 obj-$(CONFIG_RTC_DRV_PS3)	+= rtc-ps3.o
+obj-$(CONFIG_RTC_DRV_PT7C4338)	+= rtc-pt7c4338.o
 obj-$(CONFIG_RTC_DRV_PXA)	+= rtc-pxa.o
 obj-$(CONFIG_RTC_DRV_R9701)	+= rtc-r9701.o
 obj-$(CONFIG_RTC_DRV_RP5C01)	+= rtc-rp5c01.o
diff --git a/drivers/rtc/rtc-pt7c4338.c b/drivers/rtc/rtc-pt7c4338.c
new file mode 100644
index 0000000..fca52cd
--- /dev/null
+++ b/drivers/rtc/rtc-pt7c4338.c
@@ -0,0 +1,215 @@ 
+/*
+ * Copyright 2010 Freescale Semiconductor, Inc.
+ *
+ * Author:	Priyanka Jain <Priyanka.Jain@freescale.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * 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 License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * This file provides Date & Time support (no alarms) for PT7C4338 chip.
+ *
+ * This file is based on drivers/rtc/rtc-ds1307.c
+ *
+ * PT7C4338 chip is manufactured by Pericom Technology Inc.
+ * It is a serial real-time clock which provides
+ * 1)Low-power clock/calendar.
+ * 2)Programmable square-wave output.
+ * It has 56 bytes of nonvolatile RAM.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+
+/* RTC register addresses */
+#define PT7C4338_REG_SECONDS          0x00
+#define PT7C4338_REG_MINUTES          0x01
+#define PT7C4338_REG_HOURS            0x02
+#define PT7C4338_REG_AMPM             0x02
+#define PT7C4338_REG_DAY              0x03
+#define PT7C4338_REG_DATE             0x04
+#define PT7C4338_REG_MONTH            0x05
+#define PT7C4338_REG_YEAR             0x06
+#define PT7C4338_REG_CTRL_STAT        0x07
+
+/* RTC second register address bit */
+#define PT7C4338_SEC_BIT_CH           0x80	/*Clock Halt (in Register 0)*/
+
+/* RTC control and status register bits */
+#define PT7C4338_CTRL_STAT_BIT_RS0    0x1	/*Rate select 0*/
+#define PT7C4338_CTRL_STAT_BIT_RS1    0x2	/*Rate select 1*/
+#define PT7C4338_CTRL_STAT_BIT_SQWE   0x10	/*Square Wave Enable*/
+#define PT7C4338_CTRL_STAT_BIT_OSF    0x20	/*Oscillator Stop Flag*/
+#define PT7C4338_CTRL_STAT_BIT_OUT    0x80	/*Output Level Control*/
+
+static const struct i2c_device_id pt7c4338_id[] = {
+	{ "pt7c4338", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, pt7c4338_id);
+
+struct pt7c4338{
+	struct i2c_client *client;
+	struct rtc_device *rtc;
+};
+
+static int pt7c4338_read_time(struct device *dev, struct rtc_time *time)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int ret;
+	u8 buf[7];
+	u8 year, month, day, hour, minute, second;
+	u8 week, twelve_hr, am_pm;
+
+	ret = i2c_smbus_read_i2c_block_data(client,
+			PT7C4338_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 */
+	twelve_hr = hour & 0x40;
+	am_pm = hour & 0x20;
+
+	/* Write to rtc_time structure */
+	time->tm_sec = bcd2bin(second & 0x7f);
+	time->tm_min = bcd2bin(minute & 0x7f);
+	if (twelve_hr) {
+		/* Convert to 24 hr */
+		if (am_pm)
+			time->tm_hour = bcd2bin(hour & 0x10) + 12;
+		else
+			time->tm_hour = bcd2bin(hour & 0xBF);
+	} else {
+		time->tm_hour = bcd2bin(hour);
+	}
+
+	time->tm_wday = bcd2bin(week & 0x07) - 1;
+	time->tm_mday = bcd2bin(day & 0x3f);
+	time->tm_mon = bcd2bin(month & 0x1F) - 1;
+	/* assume 20YY not 19YY */
+	time->tm_year = bcd2bin(year) + 100;
+
+	return 0;
+}
+
+static int pt7c4338_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 pt7c4338*/
+	buf[0] = bin2bcd(time->tm_sec);
+	buf[1] = bin2bcd(time->tm_min);
+	buf[2] = bin2bcd(time->tm_hour);
+	buf[3] = bin2bcd(time->tm_wday + 1); /* Day of the week */
+	buf[4] = bin2bcd(time->tm_mday); /* Date */
+	buf[5] = bin2bcd(time->tm_mon + 1);
+
+	/* assume 20YY not 19YY */
+	if (time->tm_year >= 100)
+		buf[6] = bin2bcd(time->tm_year - 100);
+	else
+		buf[6] = bin2bcd(time->tm_year);
+
+	return i2c_smbus_write_i2c_block_data(client,
+					PT7C4338_REG_SECONDS, 7, buf);
+}
+
+static const struct rtc_class_ops pt7c4338_rtc_ops = {
+	.read_time = pt7c4338_read_time,
+	.set_time = pt7c4338_set_time,
+};
+
+static int pt7c4338_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	struct pt7c4338 *pt7c4338;
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	int ret;
+
+	pt7c4338 = kzalloc(sizeof(struct pt7c4338), GFP_KERNEL);
+	if (!pt7c4338)
+		return -ENOMEM;
+
+	pt7c4338->client = client;
+	i2c_set_clientdata(client, pt7c4338);
+	pt7c4338->rtc = rtc_device_register(client->name, &client->dev,
+					&pt7c4338_rtc_ops, THIS_MODULE);
+	if (IS_ERR(pt7c4338->rtc)) {
+		ret = PTR_ERR(pt7c4338->rtc);
+		dev_err(&client->dev, "unable to register the class device\n");
+		goto out_free;
+	}
+
+	return 0;
+out_free:
+	i2c_set_clientdata(client, NULL);
+	kfree(pt7c4338);
+	return ret;
+}
+
+static int __devexit pt7c4338_remove(struct i2c_client *client)
+{
+	struct pt7c4338 *pt7c4338 = i2c_get_clientdata(client);
+
+	rtc_device_unregister(pt7c4338->rtc);
+	i2c_set_clientdata(client, NULL);
+	kfree(pt7c4338);
+	return 0;
+}
+
+static struct i2c_driver pt7c4338_driver = {
+	.driver = {
+		.name = "rtc-pt7c4338",
+		.owner = THIS_MODULE,
+	},
+	.probe = pt7c4338_probe,
+	.remove = __devexit_p(pt7c4338_remove),
+	.id_table = pt7c4338_id,
+};
+
+static int __init pt7c4338_init(void)
+{
+	return i2c_add_driver(&pt7c4338_driver);
+}
+
+static void __exit pt7c4338_exit(void)
+{
+	i2c_del_driver(&pt7c4338_driver);
+}
+
+module_init(pt7c4338_init);
+module_exit(pt7c4338_exit);
+
+MODULE_AUTHOR("Priyanka Jain <Priyanka.Jain@freescale.com>");
+MODULE_DESCRIPTION("pericom Technology Inc. PT7C4338 RTC Driver");
+MODULE_LICENSE("GPL");