--- /dev/null
+/*
+ * 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"
+#define DRV_VERSION "0.2"
+
+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 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,
+ res->end - res->start + 1);
+
+ 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);
+ if (likely(IS_ERR(rtc->rtc_dev)))
+ return PTR_ERR(rtc->rtc_dev);
+
+ return 0;
+}
+
+static int gemini_rtc_remove(struct platform_device *pdev)
+{
+ struct gemini_rtc *rtc = platform_get_drvdata(pdev);
+
+ rtc_device_unregister(rtc->rtc_dev);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static struct platform_driver gemini_rtc_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = gemini_rtc_probe,
+ .remove = gemini_rtc_remove,
+};
+
+module_platform_driver_probe(gemini_rtc_driver, gemini_rtc_probe);
projects / karo-tx-linux.git / commitdiff