[PATCH][v0] RTC driver(Linux) for PT7C4338 chip.
Priyanka Jain
Priyanka.Jain at freescale.com
Mon Oct 25 19:08:58 EST 2010
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 at 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
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 at 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 at freescale.com>");
+MODULE_DESCRIPTION("pericom Technology Inc. PT7C4338 RTC Driver");
+MODULE_LICENSE("GPL");
--
1.6.5.6
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