| /* |
| * 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 __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"); |