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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131// SPDX-License-Identifier: GPL-2.0+// Copyright 2015 IBM Corp.
#include <linux/module.h>#include <linux/of.h>#include <linux/platform_device.h>#include <linux/rtc.h>#include <linux/io.h>
struct aspeed_rtc { void __iomem *base;};
#define RTC_TIME 0x00#define RTC_YEAR 0x04#define RTC_CTRL 0x10
#define RTC_UNLOCK BIT(1)#define RTC_ENABLE BIT(0)
static int aspeed_rtc_read_time(struct device *dev, struct rtc_time *tm){ struct aspeed_rtc *rtc = dev_get_drvdata(dev); unsigned int cent, year; u32 reg1, reg2;
if (!(readl(rtc->base + RTC_CTRL) & RTC_ENABLE)) { dev_dbg(dev, "%s failing as rtc disabled\n", __func__); return -EINVAL; }
do { reg2 = readl(rtc->base + RTC_YEAR); reg1 = readl(rtc->base + RTC_TIME); } while (reg2 != readl(rtc->base + RTC_YEAR));
tm->tm_mday = (reg1 >> 24) & 0x1f; tm->tm_hour = (reg1 >> 16) & 0x1f; tm->tm_min = (reg1 >> 8) & 0x3f; tm->tm_sec = (reg1 >> 0) & 0x3f;
cent = (reg2 >> 16) & 0x1f; year = (reg2 >> 8) & 0x7f; tm->tm_mon = ((reg2 >> 0) & 0x0f) - 1; tm->tm_year = year + (cent * 100) - 1900;
dev_dbg(dev, "%s %ptR", __func__, tm);
return 0;}
static int aspeed_rtc_set_time(struct device *dev, struct rtc_time *tm){ struct aspeed_rtc *rtc = dev_get_drvdata(dev); u32 reg1, reg2, ctrl; int year, cent;
cent = (tm->tm_year + 1900) / 100; year = tm->tm_year % 100;
reg1 = (tm->tm_mday << 24) | (tm->tm_hour << 16) | (tm->tm_min << 8) | tm->tm_sec;
reg2 = ((cent & 0x1f) << 16) | ((year & 0x7f) << 8) | ((tm->tm_mon + 1) & 0xf);
ctrl = readl(rtc->base + RTC_CTRL); writel(ctrl | RTC_UNLOCK, rtc->base + RTC_CTRL);
writel(reg1, rtc->base + RTC_TIME); writel(reg2, rtc->base + RTC_YEAR);
/* Re-lock and ensure enable is set now that a time is programmed */ writel(ctrl | RTC_ENABLE, rtc->base + RTC_CTRL);
return 0;}
static const struct rtc_class_ops aspeed_rtc_ops = { .read_time = aspeed_rtc_read_time, .set_time = aspeed_rtc_set_time,};
static int aspeed_rtc_probe(struct platform_device *pdev){ struct aspeed_rtc *rtc; struct rtc_device *rtc_dev;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) return -ENOMEM;
rtc->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(rtc->base)) return PTR_ERR(rtc->base);
rtc_dev = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(rtc_dev)) return PTR_ERR(rtc_dev);
platform_set_drvdata(pdev, rtc);
rtc_dev->ops = &aspeed_rtc_ops; rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_1900; rtc_dev->range_max = 38814989399LL; /* 3199-12-31 23:59:59 */
return devm_rtc_register_device(rtc_dev);}
static const struct of_device_id aspeed_rtc_match[] = { { .compatible = "aspeed,ast2400-rtc", }, { .compatible = "aspeed,ast2500-rtc", }, { .compatible = "aspeed,ast2600-rtc", }, { .compatible = "aspeed,ast2700-rtc", }, {}};MODULE_DEVICE_TABLE(of, aspeed_rtc_match);
static struct platform_driver aspeed_rtc_driver = { .driver = { .name = "aspeed-rtc", .of_match_table = aspeed_rtc_match, },};
module_platform_driver_probe(aspeed_rtc_driver, aspeed_rtc_probe);
MODULE_DESCRIPTION("ASPEED RTC driver");MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");MODULE_LICENSE("GPL");