/* * Gemini OnChip RTC * * Copyright (C) 2009 Janos Laube <janos.dev@gmail.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * Original code for older kernel 2.6.15 are from Stormlinksemi * first update from Janos Laube for > 2.6.29 kernels * * checkpatch fixes and usage of rtc-lib code * Hans Ulli Kroll <ulli.kroll@googlemail.com> */ #include <linux/rtc.h> #include <linux/io.h> #include <linux/slab.h> #include <linux/platform_device.h> #include <linux/kernel.h> #include <linux/module.h> #define DRV_NAME "rtc-gemini" MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>"); MODULE_DESCRIPTION("RTC driver for Gemini SoC"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:" DRV_NAME); struct gemini_rtc { struct rtc_device *rtc_dev; void __iomem *rtc_base; int rtc_irq; }; enum gemini_rtc_offsets { GEMINI_RTC_SECOND = 0x00, GEMINI_RTC_MINUTE = 0x04, GEMINI_RTC_HOUR = 0x08, GEMINI_RTC_DAYS = 0x0C, GEMINI_RTC_ALARM_SECOND = 0x10, GEMINI_RTC_ALARM_MINUTE = 0x14, GEMINI_RTC_ALARM_HOUR = 0x18, GEMINI_RTC_RECORD = 0x1C, GEMINI_RTC_CR = 0x20 }; static irqreturn_t gemini_rtc_interrupt(int irq, void *dev) { return IRQ_HANDLED; } /* * Looks like the RTC in the Gemini SoC is (totaly) broken * We can't read/write directly the time from RTC registers. * We must do some "offset" calculation to get the real time * * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does * the same thing, without the rtc-lib.c calls. */ static int gemini_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct gemini_rtc *rtc = dev_get_drvdata(dev); unsigned int days, hour, min, sec; unsigned long offset, time; sec = readl(rtc->rtc_base + GEMINI_RTC_SECOND); min = readl(rtc->rtc_base + GEMINI_RTC_MINUTE); hour = readl(rtc->rtc_base + GEMINI_RTC_HOUR); days = readl(rtc->rtc_base + GEMINI_RTC_DAYS); offset = readl(rtc->rtc_base + GEMINI_RTC_RECORD); time = offset + days * 86400 + hour * 3600 + min * 60 + sec; rtc_time_to_tm(time, tm); return 0; } static int gemini_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct gemini_rtc *rtc = dev_get_drvdata(dev); unsigned int sec, min, hour, day; unsigned long offset, time; if (tm->tm_year >= 2148) /* EPOCH Year + 179 */ return -EINVAL; rtc_tm_to_time(tm, &time); sec = readl(rtc->rtc_base + GEMINI_RTC_SECOND); min = readl(rtc->rtc_base + GEMINI_RTC_MINUTE); hour = readl(rtc->rtc_base + GEMINI_RTC_HOUR); day = readl(rtc->rtc_base + GEMINI_RTC_DAYS); offset = time - (day * 86400 + hour * 3600 + min * 60 + sec); writel(offset, rtc->rtc_base + GEMINI_RTC_RECORD); writel(0x01, rtc->rtc_base + GEMINI_RTC_CR); return 0; } static const struct rtc_class_ops gemini_rtc_ops = { .read_time = gemini_rtc_read_time, .set_time = gemini_rtc_set_time, }; static int gemini_rtc_probe(struct platform_device *pdev) { struct gemini_rtc *rtc; struct device *dev = &pdev->dev; struct resource *res; int ret; rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (unlikely(!rtc)) return -ENOMEM; platform_set_drvdata(pdev, rtc); res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (!res) return -ENODEV; rtc->rtc_irq = res->start; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) return -ENODEV; rtc->rtc_base = devm_ioremap(dev, res->start, resource_size(res)); ret = devm_request_irq(dev, rtc->rtc_irq, gemini_rtc_interrupt, IRQF_SHARED, pdev->name, dev); if (unlikely(ret)) return ret; rtc->rtc_dev = rtc_device_register(pdev->name, dev, &gemini_rtc_ops, THIS_MODULE); return PTR_ERR_OR_ZERO(rtc->rtc_dev); } static int gemini_rtc_remove(struct platform_device *pdev) { struct gemini_rtc *rtc = platform_get_drvdata(pdev); rtc_device_unregister(rtc->rtc_dev); return 0; } static const struct of_device_id gemini_rtc_dt_match[] = { { .compatible = "cortina,gemini-rtc" }, { } }; MODULE_DEVICE_TABLE(of, gemini_rtc_dt_match); static struct platform_driver gemini_rtc_driver = { .driver = { .name = DRV_NAME, .of_match_table = gemini_rtc_dt_match, }, .probe = gemini_rtc_probe, .remove = gemini_rtc_remove, }; module_platform_driver_probe(gemini_rtc_driver, gemini_rtc_probe);