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