linux/drivers/rtc/rtc-ds1742.c
Rob Herring 48144c2890 rtc: Explicitly include correct DT includes
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230724205456.767430-1-robh@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2023-07-27 23:31:29 +02:00

221 lines
5.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* An rtc driver for the Dallas DS1742
*
* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
*
* 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/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;
}
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;
}
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;
}
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;
}
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;
ioaddr = devm_platform_get_and_ioremap_resource(pdev, 0, &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;
ret = devm_rtc_register_device(rtc);
if (ret)
return ret;
devm_rtc_nvmem_register(rtc, &nvmem_cfg);
return 0;
}
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");