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Release 4.18 drivers/rtc/rtc-ds1742.c

Directory: drivers/rtc
/*
 * An rtc driver for the Dallas DS1742
 *
 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 *
 * 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.
 *
 * Copyright (C) 2006 Torsten Ertbjerg Rasmussen <tr@newtec.dk>
 *  - nvram size determined from resource
 *  - this ds1742 driver now supports ds1743.
 */

#include <linux/bcd.h>
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/rtc.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/module.h>


#define RTC_SIZE		8


#define RTC_CONTROL		0

#define RTC_CENTURY		0

#define RTC_SECONDS		1

#define RTC_MINUTES		2

#define RTC_HOURS		3

#define RTC_DAY			4

#define RTC_DATE		5

#define RTC_MONTH		6

#define RTC_YEAR		7


#define RTC_CENTURY_MASK	0x3f

#define RTC_SECONDS_MASK	0x7f

#define RTC_DAY_MASK		0x07

/* Bits in the Control/Century register */

#define RTC_WRITE		0x80

#define RTC_READ		0x40

/* Bits in the Seconds register */

#define RTC_STOP		0x80

/* Bits in the Day register */

#define RTC_BATT_FLAG		0x80


struct rtc_plat_data {
	
void __iomem *ioaddr_nvram;
	
void __iomem *ioaddr_rtc;
	
unsigned long last_jiffies;
};


static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct rtc_plat_data *pdata = dev_get_drvdata(dev); void __iomem *ioaddr = pdata->ioaddr_rtc; u8 century; century = bin2bcd((tm->tm_year + 1900) / 100); writeb(RTC_WRITE, ioaddr + RTC_CONTROL); writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR); writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH); writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY); writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE); writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS); writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES); writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS); /* RTC_CENTURY and RTC_CONTROL share same register */ writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY); writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Atsushi Nemoto18794.44%125.00%
Adrian Bunk84.04%125.00%
Wolfram Sang21.01%125.00%
Torsten Ertbjerg Rasmussen10.51%125.00%
Total198100.00%4100.00%


static int ds1742_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct rtc_plat_data *pdata = dev_get_drvdata(dev); void __iomem *ioaddr = pdata->ioaddr_rtc; unsigned int year, month, day, hour, minute, second, week; unsigned int century; /* give enough time to update RTC in case of continuous read */ if (pdata->last_jiffies == jiffies) msleep(1); pdata->last_jiffies = jiffies; writeb(RTC_READ, ioaddr + RTC_CONTROL); second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK; minute = readb(ioaddr + RTC_MINUTES); hour = readb(ioaddr + RTC_HOURS); day = readb(ioaddr + RTC_DATE); week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK; month = readb(ioaddr + RTC_MONTH); year = readb(ioaddr + RTC_YEAR); century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK; writeb(0, ioaddr + RTC_CONTROL); tm->tm_sec = bcd2bin(second); tm->tm_min = bcd2bin(minute); tm->tm_hour = bcd2bin(hour); tm->tm_mday = bcd2bin(day); tm->tm_wday = bcd2bin(week); tm->tm_mon = bcd2bin(month) - 1; /* year is 1900 + tm->tm_year */ tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Atsushi Nemoto23694.78%116.67%
Adrian Bunk83.21%116.67%
Wolfram Sang20.80%116.67%
Alexandre Belloni10.40%116.67%
Alexander Shiyan10.40%116.67%
Torsten Ertbjerg Rasmussen10.40%116.67%
Total249100.00%6100.00%

static const struct rtc_class_ops ds1742_rtc_ops = { .read_time = ds1742_rtc_read_time, .set_time = ds1742_rtc_set_time, };
static int ds1742_nvram_read(void *priv, unsigned int pos, void *val, size_t bytes) { struct rtc_plat_data *pdata = priv; void __iomem *ioaddr = pdata->ioaddr_nvram; u8 *buf = val; for (; bytes; bytes--) *buf++ = readb(ioaddr + pos++); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Atsushi Nemoto4365.15%120.00%
Alexandre Belloni1928.79%120.00%
Chris Wright23.03%120.00%
Rui Zhang11.52%120.00%
Torsten Ertbjerg Rasmussen11.52%120.00%
Total66100.00%5100.00%


static int ds1742_nvram_write(void *priv, unsigned int pos, void *val, size_t bytes) { struct rtc_plat_data *pdata = priv; void __iomem *ioaddr = pdata->ioaddr_nvram; u8 *buf = val; for (; bytes; bytes--) writeb(*buf++, ioaddr + pos++); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Atsushi Nemoto4568.18%125.00%
Alexandre Belloni1928.79%125.00%
Rui Zhang11.52%125.00%
Torsten Ertbjerg Rasmussen11.52%125.00%
Total66100.00%4100.00%


static int ds1742_rtc_probe(struct platform_device *pdev) { struct rtc_device *rtc; struct resource *res; unsigned int cen, sec; struct rtc_plat_data *pdata; void __iomem *ioaddr; int ret = 0; struct nvmem_config nvmem_cfg = { .name = "ds1742_nvram", .reg_read = ds1742_nvram_read, .reg_write = ds1742_nvram_write, }; pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); ioaddr = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(ioaddr)) return PTR_ERR(ioaddr); pdata->ioaddr_nvram = ioaddr; pdata->ioaddr_rtc = ioaddr + resource_size(res) - RTC_SIZE; nvmem_cfg.size = resource_size(res) - RTC_SIZE; nvmem_cfg.priv = pdata; /* turn RTC on if it was not on */ ioaddr = pdata->ioaddr_rtc; sec = readb(ioaddr + RTC_SECONDS); if (sec & RTC_STOP) { sec &= RTC_SECONDS_MASK; cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK; writeb(RTC_WRITE, ioaddr + RTC_CONTROL); writeb(sec, ioaddr + RTC_SECONDS); writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL); } if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG)) dev_warn(&pdev->dev, "voltage-low detected.\n"); pdata->last_jiffies = jiffies; platform_set_drvdata(pdev, pdata); rtc = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(rtc)) return PTR_ERR(rtc); rtc->ops = &ds1742_rtc_ops; rtc->nvram_old_abi = true; ret = rtc_register_device(rtc); if (ret) return ret; if (rtc_nvmem_register(rtc, &nvmem_cfg)) dev_err(&pdev->dev, "Unable to register nvmem\n"); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Atsushi Nemoto22365.59%327.27%
Alexandre Belloni6719.71%218.18%
Torsten Ertbjerg Rasmussen205.88%218.18%
Alexander Shiyan175.00%19.09%
Alessandro Zummo82.35%19.09%
Wolfram Sang30.88%19.09%
Jingoo Han20.59%19.09%
Total340100.00%11100.00%

static const struct of_device_id __maybe_unused ds1742_rtc_of_match[] = { { .compatible = "maxim,ds1742", }, { } }; MODULE_DEVICE_TABLE(of, ds1742_rtc_of_match); static struct platform_driver ds1742_rtc_driver = { .probe = ds1742_rtc_probe, .driver = { .name = "rtc-ds1742", .of_match_table = of_match_ptr(ds1742_rtc_of_match), }, }; module_platform_driver(ds1742_rtc_driver); MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>"); MODULE_DESCRIPTION("Dallas DS1742 RTC driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:rtc-ds1742");

Overall Contributors

PersonTokensPropCommitsCommitProp
Atsushi Nemoto88677.58%415.38%
Alexandre Belloni1069.28%311.54%
Alexander Shiyan554.82%415.38%
Torsten Ertbjerg Rasmussen433.77%27.69%
Adrian Bunk161.40%13.85%
Alessandro Zummo80.70%13.85%
Wolfram Sang70.61%27.69%
Kay Sievers50.44%13.85%
Tejun Heo30.26%13.85%
Paul Gortmaker30.26%13.85%
Jingoo Han30.26%27.69%
Chris Wright20.18%13.85%
Axel Lin20.18%13.85%
Rui Zhang20.18%13.85%
David Brownell10.09%13.85%
Total1142100.00%26100.00%
Directory: drivers/rtc
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