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path: root/drivers/rtc/rtc-pl030.c
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Diffstat (limited to 'drivers/rtc/rtc-pl030.c')
-rw-r--r--drivers/rtc/rtc-pl030.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pl030.c b/drivers/rtc/rtc-pl030.c
new file mode 100644
index 000000000..f85a1a93e
--- /dev/null
+++ b/drivers/rtc/rtc-pl030.c
@@ -0,0 +1,187 @@
+/*
+ * linux/drivers/rtc/rtc-pl030.c
+ *
+ * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/amba/bus.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#define RTC_DR (0)
+#define RTC_MR (4)
+#define RTC_STAT (8)
+#define RTC_EOI (8)
+#define RTC_LR (12)
+#define RTC_CR (16)
+#define RTC_CR_MIE (1 << 0)
+
+struct pl030_rtc {
+ struct rtc_device *rtc;
+ void __iomem *base;
+};
+
+static irqreturn_t pl030_interrupt(int irq, void *dev_id)
+{
+ struct pl030_rtc *rtc = dev_id;
+ writel(0, rtc->base + RTC_EOI);
+ return IRQ_HANDLED;
+}
+
+static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct pl030_rtc *rtc = dev_get_drvdata(dev);
+
+ rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
+ return 0;
+}
+
+static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct pl030_rtc *rtc = dev_get_drvdata(dev);
+ unsigned long time;
+ int ret;
+
+ /*
+ * At the moment, we can only deal with non-wildcarded alarm times.
+ */
+ ret = rtc_valid_tm(&alrm->time);
+ if (ret == 0)
+ ret = rtc_tm_to_time(&alrm->time, &time);
+ if (ret == 0)
+ writel(time, rtc->base + RTC_MR);
+ return ret;
+}
+
+static int pl030_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct pl030_rtc *rtc = dev_get_drvdata(dev);
+
+ rtc_time_to_tm(readl(rtc->base + RTC_DR), tm);
+
+ return 0;
+}
+
+/*
+ * Set the RTC time. Unfortunately, we can't accurately set
+ * the point at which the counter updates.
+ *
+ * Also, since RTC_LR is transferred to RTC_CR on next rising
+ * edge of the 1Hz clock, we must write the time one second
+ * in advance.
+ */
+static int pl030_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct pl030_rtc *rtc = dev_get_drvdata(dev);
+ unsigned long time;
+ int ret;
+
+ ret = rtc_tm_to_time(tm, &time);
+ if (ret == 0)
+ writel(time + 1, rtc->base + RTC_LR);
+
+ return ret;
+}
+
+static const struct rtc_class_ops pl030_ops = {
+ .read_time = pl030_read_time,
+ .set_time = pl030_set_time,
+ .read_alarm = pl030_read_alarm,
+ .set_alarm = pl030_set_alarm,
+};
+
+static int pl030_probe(struct amba_device *dev, const struct amba_id *id)
+{
+ struct pl030_rtc *rtc;
+ int ret;
+
+ ret = amba_request_regions(dev, NULL);
+ if (ret)
+ goto err_req;
+
+ rtc = devm_kzalloc(&dev->dev, sizeof(*rtc), GFP_KERNEL);
+ if (!rtc) {
+ ret = -ENOMEM;
+ goto err_rtc;
+ }
+
+ rtc->base = ioremap(dev->res.start, resource_size(&dev->res));
+ if (!rtc->base) {
+ ret = -ENOMEM;
+ goto err_rtc;
+ }
+
+ __raw_writel(0, rtc->base + RTC_CR);
+ __raw_writel(0, rtc->base + RTC_EOI);
+
+ amba_set_drvdata(dev, rtc);
+
+ ret = request_irq(dev->irq[0], pl030_interrupt, 0,
+ "rtc-pl030", rtc);
+ if (ret)
+ goto err_irq;
+
+ rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops,
+ THIS_MODULE);
+ if (IS_ERR(rtc->rtc)) {
+ ret = PTR_ERR(rtc->rtc);
+ goto err_reg;
+ }
+
+ return 0;
+
+ err_reg:
+ free_irq(dev->irq[0], rtc);
+ err_irq:
+ iounmap(rtc->base);
+ err_rtc:
+ amba_release_regions(dev);
+ err_req:
+ return ret;
+}
+
+static int pl030_remove(struct amba_device *dev)
+{
+ struct pl030_rtc *rtc = amba_get_drvdata(dev);
+
+ writel(0, rtc->base + RTC_CR);
+
+ free_irq(dev->irq[0], rtc);
+ rtc_device_unregister(rtc->rtc);
+ iounmap(rtc->base);
+ amba_release_regions(dev);
+
+ return 0;
+}
+
+static struct amba_id pl030_ids[] = {
+ {
+ .id = 0x00041030,
+ .mask = 0x000fffff,
+ },
+ { 0, 0 },
+};
+
+MODULE_DEVICE_TABLE(amba, pl030_ids);
+
+static struct amba_driver pl030_driver = {
+ .drv = {
+ .name = "rtc-pl030",
+ },
+ .probe = pl030_probe,
+ .remove = pl030_remove,
+ .id_table = pl030_ids,
+};
+
+module_amba_driver(pl030_driver);
+
+MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
+MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver");
+MODULE_LICENSE("GPL");