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