// SPDX-License-Identifier: GPL-2.0-only/* * Driver for Epson RTC-9701JE * * Copyright (C) 2008 Magnus Damm * * Based on rtc-max6902.c * * Copyright (C) 2006 8D Technologies inc. * Copyright (C) 2004 Compulab Ltd. */ #include <linux/module.h>#include <linux/kernel.h>#include <linux/platform_device.h>#include <linux/device.h>#include <linux/init.h>#include <linux/rtc.h>#include <linux/spi/spi.h>#include <linux/bcd.h>#include <linux/delay.h>#include <linux/bitops.h> #define RSECCNT	0x00	/* Second Counter */#define RMINCNT	0x01	/* Minute Counter */#define RHRCNT	0x02	/* Hour Counter */#define RWKCNT	0x03	/* Week Counter */#define RDAYCNT	0x04	/* Day Counter */#define RMONCNT	0x05	/* Month Counter */#define RYRCNT	0x06	/* Year Counter */#define R100CNT	0x07	/* Y100 Counter */#define RMINAR	0x08	/* Minute Alarm */#define RHRAR	0x09	/* Hour Alarm */#define RWKAR	0x0a	/* Week/Day Alarm */#define RTIMCNT	0x0c	/* Interval Timer */#define REXT	0x0d	/* Extension Register */#define RFLAG	0x0e	/* RTC Flag Register */#define RCR	0x0f	/* RTC Control Register */ static int write_reg(struct device *dev, int address, unsigned char data){	struct spi_device *spi = to_spi_device(dev);	unsigned char buf[2]; 	buf[0] = address & 0x7f;	buf[1] = data; 	return spi_write(spi, buf, ARRAY_SIZE(buf));} static int read_regs(struct device *dev, unsigned char *regs, int no_regs){	struct spi_device *spi = to_spi_device(dev);	u8 txbuf[1], rxbuf[1];	int k, ret; 	ret = 0; 	for (k = 0; ret == 0 && k < no_regs; k++) {		txbuf[0] = 0x80 | regs[k];		ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);		regs[k] = rxbuf[0];	} 	return ret;} static int r9701_get_datetime(struct device *dev, struct rtc_time *dt){	int ret;	unsigned char buf[] = { RSECCNT, RMINCNT, RHRCNT,				RDAYCNT, RMONCNT, RYRCNT }; 	ret = read_regs(dev, buf, ARRAY_SIZE(buf));	if (ret)		return ret; 	dt->tm_sec = bcd2bin(buf[0]); /* RSECCNT */	dt->tm_min = bcd2bin(buf[1]); /* RMINCNT */	dt->tm_hour = bcd2bin(buf[2]); /* RHRCNT */ 	dt->tm_mday = bcd2bin(buf[3]); /* RDAYCNT */	dt->tm_mon = bcd2bin(buf[4]) - 1; /* RMONCNT */	dt->tm_year = bcd2bin(buf[5]) + 100; /* RYRCNT */ 	return 0;} static int r9701_set_datetime(struct device *dev, struct rtc_time *dt){	int ret; 	ret = write_reg(dev, RHRCNT, bin2bcd(dt->tm_hour));	ret = ret ? ret : write_reg(dev, RMINCNT, bin2bcd(dt->tm_min));	ret = ret ? ret : write_reg(dev, RSECCNT, bin2bcd(dt->tm_sec));	ret = ret ? ret : write_reg(dev, RDAYCNT, bin2bcd(dt->tm_mday));	ret = ret ? ret : write_reg(dev, RMONCNT, bin2bcd(dt->tm_mon + 1));	ret = ret ? ret : write_reg(dev, RYRCNT, bin2bcd(dt->tm_year - 100)); 	return ret;} static const struct rtc_class_ops r9701_rtc_ops = {	.read_time	= r9701_get_datetime,	.set_time	= r9701_set_datetime,}; static int r9701_probe(struct spi_device *spi){	struct rtc_device *rtc;	unsigned char tmp;	int res; 	tmp = R100CNT;	res = read_regs(&spi->dev, &tmp, 1);	if (res || tmp != 0x20) {		dev_err(&spi->dev, "cannot read RTC register\n");		return -ENODEV;	} 	rtc = devm_rtc_allocate_device(&spi->dev);	if (IS_ERR(rtc))		return PTR_ERR(rtc); 	spi_set_drvdata(spi, rtc);	rtc->ops = &r9701_rtc_ops;	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;	rtc->range_max = RTC_TIMESTAMP_END_2099; 	return devm_rtc_register_device(rtc);} static struct spi_driver r9701_driver = {	.driver = {		.name	= "rtc-r9701",	},	.probe	= r9701_probe,}; module_spi_driver(r9701_driver); MODULE_DESCRIPTION("r9701 spi RTC driver");MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");MODULE_LICENSE("GPL");MODULE_ALIAS("spi:rtc-r9701");