[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/Kconfig b/drivers/rtc/Kconfig
index 65d090dbef460e70ccb4aae266e08ff8ba7576c7..875ff5e5792ae8295d1d52f5133f76f43a3a88a5 100644 (file)
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -157,6 +157,16 @@ config RTC_DRV_VR41XX
          To compile this driver as a module, choose M here: the
          module will be called rtc-vr41xx.
 
+config RTC_DRV_PL031
+       tristate "ARM AMBA PL031 RTC"
+       depends on RTC_CLASS && ARM_AMBA
+       help
+         If you say Y here you will get access to ARM AMBA
+         PrimeCell PL031 UART found on certain ARM SOCs.
+
+         To compile this driver as a module, choose M here: the
+         module will be called rtc-pl031.
+
 config RTC_DRV_TEST
        tristate "Test driver/device"
        depends on RTC_CLASS

diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index a9ca0f1716868154f9e5419754864543108f07e6..1b3f32ecec808072a95811acc5b57d4bfb852496 100644 (file)
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -20,3 +20,4 @@ obj-$(CONFIG_RTC_DRV_M48T86)  += rtc-m48t86.o
 obj-$(CONFIG_RTC_DRV_EP93XX)   += rtc-ep93xx.o
 obj-$(CONFIG_RTC_DRV_SA1100)   += rtc-sa1100.o
 obj-$(CONFIG_RTC_DRV_VR41XX)   += rtc-vr41xx.o
+obj-$(CONFIG_RTC_DRV_PL031)    += rtc-pl031.o

diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
new file mode 100644 (file)
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");