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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146// SPDX-License-Identifier: GPL-2.0-or-later/* * The Netronix embedded controller is a microcontroller found in some * e-book readers designed by the original design manufacturer Netronix, Inc. * It contains RTC, battery monitoring, system power management, and PWM * functionality. * * This driver implements access to the RTC time and date. * * Copyright 2020 Jonathan Neuschäfer <j.neuschaefer@gmx.net> */
#include <linux/mfd/ntxec.h>#include <linux/module.h>#include <linux/platform_device.h>#include <linux/regmap.h>#include <linux/rtc.h>#include <linux/types.h>
struct ntxec_rtc { struct device *dev; struct ntxec *ec;};
#define NTXEC_REG_WRITE_YEAR 0x10#define NTXEC_REG_WRITE_MONTH 0x11#define NTXEC_REG_WRITE_DAY 0x12#define NTXEC_REG_WRITE_HOUR 0x13#define NTXEC_REG_WRITE_MINUTE 0x14#define NTXEC_REG_WRITE_SECOND 0x15
#define NTXEC_REG_READ_YEAR_MONTH 0x20#define NTXEC_REG_READ_MDAY_HOUR 0x21#define NTXEC_REG_READ_MINUTE_SECOND 0x23
static int ntxec_read_time(struct device *dev, struct rtc_time *tm){ struct ntxec_rtc *rtc = dev_get_drvdata(dev); unsigned int value; int res;
retry: res = regmap_read(rtc->ec->regmap, NTXEC_REG_READ_MINUTE_SECOND, &value); if (res < 0) return res;
tm->tm_min = value >> 8; tm->tm_sec = value & 0xff;
res = regmap_read(rtc->ec->regmap, NTXEC_REG_READ_MDAY_HOUR, &value); if (res < 0) return res;
tm->tm_mday = value >> 8; tm->tm_hour = value & 0xff;
res = regmap_read(rtc->ec->regmap, NTXEC_REG_READ_YEAR_MONTH, &value); if (res < 0) return res;
tm->tm_year = (value >> 8) + 100; tm->tm_mon = (value & 0xff) - 1;
/* * Read the minutes/seconds field again. If it changed since the first * read, we can't assume that the values read so far are consistent, * and should start from the beginning. */ res = regmap_read(rtc->ec->regmap, NTXEC_REG_READ_MINUTE_SECOND, &value); if (res < 0) return res;
if (tm->tm_min != value >> 8 || tm->tm_sec != (value & 0xff)) goto retry;
return 0;}
static int ntxec_set_time(struct device *dev, struct rtc_time *tm){ struct ntxec_rtc *rtc = dev_get_drvdata(dev);
/* * To avoid time overflows while we're writing the full date/time, * set the seconds field to zero before doing anything else. For the * next 59 seconds (plus however long it takes until the RTC's next * update of the second field), the seconds field will not overflow * into the other fields. */ struct reg_sequence regs[] = { { NTXEC_REG_WRITE_SECOND, ntxec_reg8(0) }, { NTXEC_REG_WRITE_YEAR, ntxec_reg8(tm->tm_year - 100) }, { NTXEC_REG_WRITE_MONTH, ntxec_reg8(tm->tm_mon + 1) }, { NTXEC_REG_WRITE_DAY, ntxec_reg8(tm->tm_mday) }, { NTXEC_REG_WRITE_HOUR, ntxec_reg8(tm->tm_hour) }, { NTXEC_REG_WRITE_MINUTE, ntxec_reg8(tm->tm_min) }, { NTXEC_REG_WRITE_SECOND, ntxec_reg8(tm->tm_sec) }, };
return regmap_multi_reg_write(rtc->ec->regmap, regs, ARRAY_SIZE(regs));}
static const struct rtc_class_ops ntxec_rtc_ops = { .read_time = ntxec_read_time, .set_time = ntxec_set_time,};
static int ntxec_rtc_probe(struct platform_device *pdev){ struct rtc_device *dev; struct ntxec_rtc *rtc;
device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) return -ENOMEM;
rtc->dev = &pdev->dev; rtc->ec = dev_get_drvdata(pdev->dev.parent); platform_set_drvdata(pdev, rtc);
dev = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(dev)) return PTR_ERR(dev);
dev->ops = &ntxec_rtc_ops; dev->range_min = RTC_TIMESTAMP_BEGIN_2000; dev->range_max = 9025257599LL; /* 2255-12-31 23:59:59 */
return devm_rtc_register_device(dev);}
static struct platform_driver ntxec_rtc_driver = { .driver = { .name = "ntxec-rtc", }, .probe = ntxec_rtc_probe,};module_platform_driver(ntxec_rtc_driver);
MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>");MODULE_DESCRIPTION("RTC driver for Netronix EC");MODULE_LICENSE("GPL");MODULE_ALIAS("platform:ntxec-rtc");