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Release 4.14 drivers/rtc/rtc-rx8581.c

Directory: drivers/rtc
/*
 * An I2C driver for the Epson RX8581 RTC
 *
 * Author: Martyn Welch <martyn.welch@ge.com>
 * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
 * Copyright 2005-06 Tower Technologies
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/log2.h>


#define RX8581_REG_SC		0x00 
/* Second in BCD */

#define RX8581_REG_MN		0x01 
/* Minute in BCD */

#define RX8581_REG_HR		0x02 
/* Hour in BCD */

#define RX8581_REG_DW		0x03 
/* Day of Week */

#define RX8581_REG_DM		0x04 
/* Day of Month in BCD */

#define RX8581_REG_MO		0x05 
/* Month in BCD */

#define RX8581_REG_YR		0x06 
/* Year in BCD */

#define RX8581_REG_RAM		0x07 
/* RAM */

#define RX8581_REG_AMN		0x08 
/* Alarm Min in BCD*/

#define RX8581_REG_AHR		0x09 
/* Alarm Hour in BCD */

#define RX8581_REG_ADM		0x0A

#define RX8581_REG_ADW		0x0A

#define RX8581_REG_TMR0		0x0B

#define RX8581_REG_TMR1		0x0C

#define RX8581_REG_EXT		0x0D 
/* Extension Register */

#define RX8581_REG_FLAG		0x0E 
/* Flag Register */

#define RX8581_REG_CTRL		0x0F 
/* Control Register */


/* Flag Register bit definitions */

#define RX8581_FLAG_UF		0x20 
/* Update */

#define RX8581_FLAG_TF		0x10 
/* Timer */

#define RX8581_FLAG_AF		0x08 
/* Alarm */

#define RX8581_FLAG_VLF		0x02 
/* Voltage Low */

/* Control Register bit definitions */

#define RX8581_CTRL_UIE		0x20 
/* Update Interrupt Enable */

#define RX8581_CTRL_TIE		0x10 
/* Timer Interrupt Enable */

#define RX8581_CTRL_AIE		0x08 
/* Alarm Interrupt Enable */

#define RX8581_CTRL_STOP	0x02 
/* STOP bit */

#define RX8581_CTRL_RESET	0x01 
/* RESET bit */


struct rx8581 {
	
struct i2c_client	*client;
	
struct rtc_device	*rtc;
	
s32 (*read_block_data)(const struct i2c_client *client, u8 command,
				u8 length, u8 *values);
	
s32 (*write_block_data)(const struct i2c_client *client, u8 command,
				u8 length, const u8 *values);
};


static struct i2c_driver rx8581_driver;


static int rx8581_read_block_data(const struct i2c_client *client, u8 command, u8 length, u8 *values) { s32 i, data; for (i = 0; i < length; i++) { data = i2c_smbus_read_byte_data(client, command + i); if (data < 0) return data; values[i] = data; } return i; }

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static int rx8581_write_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values) { s32 i, ret; for (i = 0; i < length; i++) { ret = i2c_smbus_write_byte_data(client, command + i, values[i]); if (ret < 0) return ret; } return length; }

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/* * In the routines that deal directly with the rx8581 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. */
static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm) { unsigned char date[7]; int data, err; struct rx8581 *rx8581 = i2c_get_clientdata(client); /* First we ensure that the "update flag" is not set, we read the * time and date then re-read the "update flag". If the update flag * has been set, we know that the time has changed during the read so * we repeat the whole process again. */ data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG); if (data < 0) { dev_err(&client->dev, "Unable to read device flags\n"); return -EIO; } do { /* If update flag set, clear it */ if (data & RX8581_FLAG_UF) { err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF)); if (err != 0) { dev_err(&client->dev, "Unable to write device flags\n"); return -EIO; } } /* Now read time and date */ err = rx8581->read_block_data(client, RX8581_REG_SC, 7, date); if (err < 0) { dev_err(&client->dev, "Unable to read date\n"); return -EIO; } /* Check flag register */ data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG); if (data < 0) { dev_err(&client->dev, "Unable to read device flags\n"); return -EIO; } } while (data & RX8581_FLAG_UF); if (data & RX8581_FLAG_VLF) dev_info(&client->dev, "low voltage detected, date/time is not reliable.\n"); dev_dbg(&client->dev, "%s: raw data is sec=%02x, min=%02x, hr=%02x, " "wday=%02x, mday=%02x, mon=%02x, year=%02x\n", __func__, date[0], date[1], date[2], date[3], date[4], date[5], date[6]); tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F); tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F); tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */ tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F); tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F); tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ tm->tm_year = bcd2bin(date[RX8581_REG_YR]); if (tm->tm_year < 70) tm->tm_year += 100; /* assume we are in 1970...2069 */ dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); err = rtc_valid_tm(tm); if (err < 0) dev_err(&client->dev, "retrieved date/time is not valid.\n"); return err; }

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Martyn Welch42996.84%150.00%
Andreas Werner143.16%150.00%
Total443100.00%2100.00%


static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm) { int data, err; unsigned char buf[7]; struct rx8581 *rx8581 = i2c_get_clientdata(client); dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); /* hours, minutes and seconds */ buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec); buf[RX8581_REG_MN] = bin2bcd(tm->tm_min); buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour); buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday); /* month, 1 - 12 */ buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1); /* year and century */ buf[RX8581_REG_YR] = bin2bcd(tm->tm_year % 100); buf[RX8581_REG_DW] = (0x1 << tm->tm_wday); /* Stop the clock */ data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL); if (data < 0) { dev_err(&client->dev, "Unable to read control register\n"); return -EIO; } err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL, (data | RX8581_CTRL_STOP)); if (err < 0) { dev_err(&client->dev, "Unable to write control register\n"); return -EIO; } /* write register's data */ err = rx8581->write_block_data(client, RX8581_REG_SC, 7, buf); if (err < 0) { dev_err(&client->dev, "Unable to write to date registers\n"); return -EIO; } /* get VLF and clear it */ data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG); if (data < 0) { dev_err(&client->dev, "Unable to read flag register\n"); return -EIO; } err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG, (data & ~(RX8581_FLAG_VLF))); if (err != 0) { dev_err(&client->dev, "Unable to write flag register\n"); return -EIO; } /* Restart the clock */ data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL); if (data < 0) { dev_err(&client->dev, "Unable to read control register\n"); return -EIO; } err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL, (data & ~(RX8581_CTRL_STOP))); if (err != 0) { dev_err(&client->dev, "Unable to write control register\n"); return -EIO; } return 0; }

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Martyn Welch33779.29%133.33%
Rudolf Marek7517.65%133.33%
Andreas Werner133.06%133.33%
Total425100.00%3100.00%


static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm) { return rx8581_get_datetime(to_i2c_client(dev), tm); }

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Martyn Welch27100.00%1100.00%
Total27100.00%1100.00%


static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm) { return rx8581_set_datetime(to_i2c_client(dev), tm); }

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Martyn Welch27100.00%1100.00%
Total27100.00%1100.00%

static const struct rtc_class_ops rx8581_rtc_ops = { .read_time = rx8581_rtc_read_time, .set_time = rx8581_rtc_set_time, };
static int rx8581_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct rx8581 *rx8581; dev_dbg(&client->dev, "%s\n", __func__); if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA) && !i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) return -EIO; rx8581 = devm_kzalloc(&client->dev, sizeof(struct rx8581), GFP_KERNEL); if (!rx8581) return -ENOMEM; i2c_set_clientdata(client, rx8581); rx8581->client = client; if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) { rx8581->read_block_data = i2c_smbus_read_i2c_block_data; rx8581->write_block_data = i2c_smbus_write_i2c_block_data; } else { rx8581->read_block_data = rx8581_read_block_data; rx8581->write_block_data = rx8581_write_block_data; } rx8581->rtc = devm_rtc_device_register(&client->dev, rx8581_driver.driver.name, &rx8581_rtc_ops, THIS_MODULE); if (IS_ERR(rx8581->rtc)) { dev_err(&client->dev, "unable to register the class device\n"); return PTR_ERR(rx8581->rtc); } return 0; }

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PersonTokensPropCommitsCommitProp
Andreas Werner11257.44%133.33%
Martyn Welch7739.49%133.33%
Jingoo Han63.08%133.33%
Total195100.00%3100.00%

static const struct i2c_device_id rx8581_id[] = { { "rx8581", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, rx8581_id); static const struct of_device_id rx8581_of_match[] = { { .compatible = "epson,rx8581" }, { } }; MODULE_DEVICE_TABLE(of, rx8581_of_match); static struct i2c_driver rx8581_driver = { .driver = { .name = "rtc-rx8581", .of_match_table = of_match_ptr(rx8581_of_match), }, .probe = rx8581_probe, .id_table = rx8581_id, }; module_i2c_driver(rx8581_driver); MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>"); MODULE_DESCRIPTION("Epson RX-8581 RTC driver"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Martyn Welch113571.20%228.57%
Andreas Werner34421.58%114.29%
Rudolf Marek754.71%114.29%
Javier Martinez Canillas332.07%114.29%
Jingoo Han60.38%114.29%
Axel Lin10.06%114.29%
Total1594100.00%7100.00%
Directory: drivers/rtc
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