--- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -603,6 +603,15 @@ config RTC_DRV_S5M This driver can also be built as a module. If so, the module will be called rtc-s5m. +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" --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -116,6 +116,7 @@ obj-$(CONFIG_RTC_DRV_PL030) += rtc-pl030 obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o obj-$(CONFIG_RTC_DRV_PM8XXX) += rtc-pm8xxx.o obj-$(CONFIG_RTC_DRV_PS3) += rtc-ps3.o +obj-$(CONFIG_RTC_DRV_PT7C4338) += rtc-pt7c4338.o obj-$(CONFIG_RTC_DRV_PUV3) += rtc-puv3.o obj-$(CONFIG_RTC_DRV_PXA) += rtc-pxa.o obj-$(CONFIG_RTC_DRV_R9701) += rtc-r9701.o --- /dev/null +++ b/drivers/rtc/rtc-pt7c4338.c @@ -0,0 +1,216 @@ +/* + * 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/slab.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 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 = 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");