[PATCH] Add driver for ARM AMBA PL031 RTC
Add a driver for the ARM PL031 RTC found on some ARM SOCs. The driver is
fairly trivial as the RTC only provides a read/write and alarm capability.
[akpm@osdl.org: compile fix]
Signed-off-by: Deepak <dsaxena@plexity.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
new file mode 100644
index 0000000..ee53863
--- /dev/null
+++ b/drivers/rtc/rtc-pl031.c
@@ -0,0 +1,233 @@
+/*
+ * drivers/rtc/rtc-pl031.c
+ *
+ * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC
+ *
+ * Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ * Copyright 2006 (c) MontaVista Software, Inc.
+ *
+ * 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.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/string.h>
+#include <linux/pm.h>
+
+#include <linux/amba/bus.h>
+
+#include <asm/io.h>
+#include <asm/bitops.h>
+#include <asm/hardware.h>
+#include <asm/irq.h>
+#include <asm/rtc.h>
+
+/*
+ * Register definitions
+ */
+#define RTC_DR 0x00 /* Data read register */
+#define RTC_MR 0x04 /* Match register */
+#define RTC_LR 0x08 /* Data load register */
+#define RTC_CR 0x0c /* Control register */
+#define RTC_IMSC 0x10 /* Interrupt mask and set register */
+#define RTC_RIS 0x14 /* Raw interrupt status register */
+#define RTC_MIS 0x18 /* Masked interrupt status register */
+#define RTC_ICR 0x1c /* Interrupt clear register */
+
+struct pl031_local {
+ struct rtc_device *rtc;
+ void __iomem *base;
+};
+
+static irqreturn_t pl031_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ struct rtc_device *rtc = dev_id;
+
+ rtc_update_irq(&rtc->class_dev, 1, RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+static int pl031_open(struct device *dev)
+{
+ /*
+ * We request IRQ in pl031_probe, so nothing to do here...
+ */
+ return 0;
+}
+
+static void pl031_release(struct device *dev)
+{
+}
+
+static int pl031_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+
+ switch (cmd) {
+ case RTC_AIE_OFF:
+ __raw_writel(1, ldata->base + RTC_MIS);
+ return 0;
+ case RTC_AIE_ON:
+ __raw_writel(0, ldata->base + RTC_MIS);
+ return 0;
+ }
+
+ return -ENOIOCTLCMD;
+}
+
+static int pl031_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+
+ rtc_time_to_tm(__raw_readl(ldata->base + RTC_DR), tm);
+
+ return 0;
+}
+
+static int pl031_set_time(struct device *dev, struct rtc_time *tm)
+{
+ unsigned long time;
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+
+ rtc_tm_to_time(tm, &time);
+ __raw_writel(time, ldata->base + RTC_LR);
+
+ return 0;
+}
+
+static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+
+ rtc_time_to_tm(__raw_readl(ldata->base + RTC_MR), &alarm->time);
+ alarm->pending = __raw_readl(ldata->base + RTC_RIS);
+ alarm->enabled = __raw_readl(ldata->base + RTC_IMSC);
+
+ return 0;
+}
+
+static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+ unsigned long time;
+
+ rtc_tm_to_time(&alarm->time, &time);
+
+ __raw_writel(time, ldata->base + RTC_MR);
+ __raw_writel(!alarm->enabled, ldata->base + RTC_MIS);
+
+ return 0;
+}
+
+static struct rtc_class_ops pl031_ops = {
+ .open = pl031_open,
+ .release = pl031_release,
+ .ioctl = pl031_ioctl,
+ .read_time = pl031_read_time,
+ .set_time = pl031_set_time,
+ .read_alarm = pl031_read_alarm,
+ .set_alarm = pl031_set_alarm,
+};
+
+static int pl031_remove(struct amba_device *adev)
+{
+ struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
+
+ if (ldata) {
+ dev_set_drvdata(&adev->dev, NULL);
+ free_irq(adev->irq[0], ldata->rtc);
+ rtc_device_unregister(ldata->rtc);
+ iounmap(ldata->base);
+ kfree(ldata);
+ }
+
+ return 0;
+}
+
+static int pl031_probe(struct amba_device *adev, void *id)
+{
+ int ret;
+ struct pl031_local *ldata;
+
+
+ ldata = kmalloc(sizeof(struct pl031_local), GFP_KERNEL);
+ if (!ldata) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ dev_set_drvdata(&adev->dev, ldata);
+
+ ldata->base = ioremap(adev->res.start,
+ adev->res.end - adev->res.start + 1);
+ if (!ldata->base) {
+ ret = -ENOMEM;
+ goto out_no_remap;
+ }
+
+ if (request_irq(adev->irq[0], pl031_interrupt, SA_INTERRUPT,
+ "rtc-pl031", ldata->rtc)) {
+ ret = -EIO;
+ goto out_no_irq;
+ }
+
+ ldata->rtc = rtc_device_register("pl031", &adev->dev, &pl031_ops,
+ THIS_MODULE);
+ if (IS_ERR(ldata->rtc)) {
+ ret = PTR_ERR(ldata->rtc);
+ goto out_no_rtc;
+ }
+
+ return 0;
+
+out_no_rtc:
+ free_irq(adev->irq[0], ldata->rtc);
+out_no_irq:
+ iounmap(ldata->base);
+out_no_remap:
+ dev_set_drvdata(&adev->dev, NULL);
+ kfree(ldata);
+out:
+ return ret;
+}
+
+static struct amba_id pl031_ids[] __initdata = {
+ {
+ .id = 0x00041031,
+ .mask = 0x000fffff, },
+ {0, 0},
+};
+
+static struct amba_driver pl031_driver = {
+ .drv = {
+ .name = "rtc-pl031",
+ },
+ .id_table = pl031_ids,
+ .probe = pl031_probe,
+ .remove = pl031_remove,
+};
+
+static int __init pl031_init(void)
+{
+ return amba_driver_register(&pl031_driver);
+}
+
+static void __exit pl031_exit(void)
+{
+ amba_driver_unregister(&pl031_driver);
+}
+
+module_init(pl031_init);
+module_exit(pl031_exit);
+
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net");
+MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");
+MODULE_LICENSE("GPL");