mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-14 15:54:15 +08:00
3821a065f5
An spi_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Andrew F. Davis <afd@ti.com> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Mark Brown <broonie@kernel.org>
159 lines
3.9 KiB
C
159 lines
3.9 KiB
C
/* drivers/rtc/rtc-max6902.c
|
|
*
|
|
* Copyright (C) 2006 8D Technologies inc.
|
|
* Copyright (C) 2004 Compulab Ltd.
|
|
*
|
|
* 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.
|
|
*
|
|
* Driver for MAX6902 spi RTC
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/init.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/spi/spi.h>
|
|
#include <linux/bcd.h>
|
|
|
|
#define MAX6902_REG_SECONDS 0x01
|
|
#define MAX6902_REG_MINUTES 0x03
|
|
#define MAX6902_REG_HOURS 0x05
|
|
#define MAX6902_REG_DATE 0x07
|
|
#define MAX6902_REG_MONTH 0x09
|
|
#define MAX6902_REG_DAY 0x0B
|
|
#define MAX6902_REG_YEAR 0x0D
|
|
#define MAX6902_REG_CONTROL 0x0F
|
|
#define MAX6902_REG_CENTURY 0x13
|
|
|
|
static int max6902_set_reg(struct device *dev, unsigned char address,
|
|
unsigned char data)
|
|
{
|
|
struct spi_device *spi = to_spi_device(dev);
|
|
unsigned char buf[2];
|
|
|
|
/* MSB must be '0' to write */
|
|
buf[0] = address & 0x7f;
|
|
buf[1] = data;
|
|
|
|
return spi_write_then_read(spi, buf, 2, NULL, 0);
|
|
}
|
|
|
|
static int max6902_get_reg(struct device *dev, unsigned char address,
|
|
unsigned char *data)
|
|
{
|
|
struct spi_device *spi = to_spi_device(dev);
|
|
|
|
/* Set MSB to indicate read */
|
|
*data = address | 0x80;
|
|
|
|
return spi_write_then_read(spi, data, 1, data, 1);
|
|
}
|
|
|
|
static int max6902_read_time(struct device *dev, struct rtc_time *dt)
|
|
{
|
|
int err, century;
|
|
struct spi_device *spi = to_spi_device(dev);
|
|
unsigned char buf[8];
|
|
|
|
buf[0] = 0xbf; /* Burst read */
|
|
|
|
err = spi_write_then_read(spi, buf, 1, buf, 8);
|
|
if (err != 0)
|
|
return err;
|
|
|
|
/* The chip sends data in this order:
|
|
* Seconds, Minutes, Hours, Date, Month, Day, Year */
|
|
dt->tm_sec = bcd2bin(buf[0]);
|
|
dt->tm_min = bcd2bin(buf[1]);
|
|
dt->tm_hour = bcd2bin(buf[2]);
|
|
dt->tm_mday = bcd2bin(buf[3]);
|
|
dt->tm_mon = bcd2bin(buf[4]) - 1;
|
|
dt->tm_wday = bcd2bin(buf[5]);
|
|
dt->tm_year = bcd2bin(buf[6]);
|
|
|
|
/* Read century */
|
|
err = max6902_get_reg(dev, MAX6902_REG_CENTURY, &buf[0]);
|
|
if (err != 0)
|
|
return err;
|
|
|
|
century = bcd2bin(buf[0]) * 100;
|
|
|
|
dt->tm_year += century;
|
|
dt->tm_year -= 1900;
|
|
|
|
return rtc_valid_tm(dt);
|
|
}
|
|
|
|
static int max6902_set_time(struct device *dev, struct rtc_time *dt)
|
|
{
|
|
dt->tm_year = dt->tm_year + 1900;
|
|
|
|
/* Remove write protection */
|
|
max6902_set_reg(dev, MAX6902_REG_CONTROL, 0);
|
|
|
|
max6902_set_reg(dev, MAX6902_REG_SECONDS, bin2bcd(dt->tm_sec));
|
|
max6902_set_reg(dev, MAX6902_REG_MINUTES, bin2bcd(dt->tm_min));
|
|
max6902_set_reg(dev, MAX6902_REG_HOURS, bin2bcd(dt->tm_hour));
|
|
|
|
max6902_set_reg(dev, MAX6902_REG_DATE, bin2bcd(dt->tm_mday));
|
|
max6902_set_reg(dev, MAX6902_REG_MONTH, bin2bcd(dt->tm_mon + 1));
|
|
max6902_set_reg(dev, MAX6902_REG_DAY, bin2bcd(dt->tm_wday));
|
|
max6902_set_reg(dev, MAX6902_REG_YEAR, bin2bcd(dt->tm_year % 100));
|
|
max6902_set_reg(dev, MAX6902_REG_CENTURY, bin2bcd(dt->tm_year / 100));
|
|
|
|
/* Compulab used a delay here. However, the datasheet
|
|
* does not mention a delay being required anywhere... */
|
|
/* delay(2000); */
|
|
|
|
/* Write protect */
|
|
max6902_set_reg(dev, MAX6902_REG_CONTROL, 0x80);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_class_ops max6902_rtc_ops = {
|
|
.read_time = max6902_read_time,
|
|
.set_time = max6902_set_time,
|
|
};
|
|
|
|
static int max6902_probe(struct spi_device *spi)
|
|
{
|
|
struct rtc_device *rtc;
|
|
unsigned char tmp;
|
|
int res;
|
|
|
|
spi->mode = SPI_MODE_3;
|
|
spi->bits_per_word = 8;
|
|
spi_setup(spi);
|
|
|
|
res = max6902_get_reg(&spi->dev, MAX6902_REG_SECONDS, &tmp);
|
|
if (res != 0)
|
|
return res;
|
|
|
|
rtc = devm_rtc_device_register(&spi->dev, "max6902",
|
|
&max6902_rtc_ops, THIS_MODULE);
|
|
if (IS_ERR(rtc))
|
|
return PTR_ERR(rtc);
|
|
|
|
spi_set_drvdata(spi, rtc);
|
|
return 0;
|
|
}
|
|
|
|
static struct spi_driver max6902_driver = {
|
|
.driver = {
|
|
.name = "rtc-max6902",
|
|
},
|
|
.probe = max6902_probe,
|
|
};
|
|
|
|
module_spi_driver(max6902_driver);
|
|
|
|
MODULE_DESCRIPTION("max6902 spi RTC driver");
|
|
MODULE_AUTHOR("Raphael Assenat");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("spi:rtc-max6902");
|