parisc: add rtc platform driver

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

arch/parisc/Kconfig

@@ -9,6 +9,8 @@ config PARISC
 	def_bool y
 	select HAVE_IDE
 	select HAVE_OPROFILE
+	select RTC_CLASS
+	select RTC_DRV_PARISC
 	help
 	  The PA-RISC microprocessor is designed by Hewlett-Packard and used
 	  in many of their workstations & servers (HP9000 700 and 800 series,

arch/parisc/kernel/time.c

@@ -23,6 +23,7 @@
 #include <linux/smp.h>
 #include <linux/profile.h>
 #include <linux/clocksource.h>
+#include <linux/platform_device.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
@@ -215,6 +216,24 @@ void __init start_cpu_itimer(void)
 	cpu_data[cpu].it_value = next_tick;
 }
 
+struct platform_device rtc_parisc_dev = {
+	.name = "rtc-parisc",
+	.id = -1,
+};
+
+static int __init rtc_init(void)
+{
+	int ret;
+
+	ret = platform_device_register(&rtc_parisc_dev);
+	if (ret < 0)
+		printk(KERN_ERR "unable to register rtc device...\n");
+
+	/* not necessarily an error */
+	return 0;
+}
+module_init(rtc_init);
+
 void __init time_init(void)
 {
 	static struct pdc_tod tod_data;
@@ -245,4 +264,3 @@ void __init time_init(void)
 		xtime.tv_nsec = 0;
 	}
 }
-

drivers/rtc/Kconfig

@@ -575,6 +575,14 @@ config RTC_DRV_RS5C313
 	help
 	  If you say yes here you get support for the Ricoh RS5C313 RTC chips.
 
+config RTC_DRV_PARISC
+	tristate "PA-RISC firmware RTC support"
+	depends on PARISC
+	help
+	  Say Y or M here to enable RTC support on PA-RISC systems using
+	  firmware calls. If you do not know what you are doing, you should
+	  just say Y.
+
 config RTC_DRV_PPC
        tristate "PowerPC machine dependent RTC support"
        depends on PPC_MERGE

drivers/rtc/Makefile

@@ -45,6 +45,7 @@ obj-$(CONFIG_RTC_DRV_PCF8563)	+= rtc-pcf8563.o
 obj-$(CONFIG_RTC_DRV_PCF8583)	+= rtc-pcf8583.o
 obj-$(CONFIG_RTC_DRV_PL030)	+= rtc-pl030.o
 obj-$(CONFIG_RTC_DRV_PL031)	+= rtc-pl031.o
+obj-$(CONFIG_RTC_DRV_PARISC)	+= rtc-parisc.o
 obj-$(CONFIG_RTC_DRV_PPC)	+= rtc-ppc.o
 obj-$(CONFIG_RTC_DRV_R9701)	+= rtc-r9701.o
 obj-$(CONFIG_RTC_DRV_RS5C313)	+= rtc-rs5c313.o

drivers/rtc/rtc-parisc.c

+/* rtc-parisc: RTC for HP PA-RISC firmware
+ *
+ * Copyright (C) 2008 Kyle McMartin <kyle@mcmartin.ca>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/platform_device.h>
+
+#include <asm/rtc.h>
+
+/* as simple as can be, and no simpler. */
+struct parisc_rtc {
+	struct rtc_device *rtc;
+	spinlock_t lock;
+};
+
+static int parisc_get_time(struct device *dev, struct rtc_time *tm)
+{
+	struct parisc_rtc *p = dev_get_drvdata(dev);
+	unsigned long flags, ret;
+
+	spin_lock_irqsave(&p->lock, flags);
+	ret = get_rtc_time(tm);
+	spin_unlock_irqrestore(&p->lock, flags);
+
+	if (ret & RTC_BATT_BAD)
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
+static int parisc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct parisc_rtc *p = dev_get_drvdata(dev);
+	unsigned long flags, ret;
+
+	spin_lock_irqsave(&p->lock, flags);
+	ret = set_rtc_time(tm);
+	spin_unlock_irqrestore(&p->lock, flags);
+
+	if (ret < 0)
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
+static const struct rtc_class_ops parisc_rtc_ops = {
+	.read_time = parisc_get_time,
+	.set_time = parisc_set_time,
+};
+
+static int __devinit parisc_rtc_probe(struct platform_device *dev)
+{
+	struct parisc_rtc *p;
+
+	p = kzalloc(sizeof (*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	spin_lock_init(&p->lock);
+
+	p->rtc = rtc_device_register("rtc-parisc", &dev->dev, &parisc_rtc_ops,
+					THIS_MODULE);
+	if (IS_ERR(p->rtc)) {
+		int err = PTR_ERR(p->rtc);
+		kfree(p);
+		return err;
+	}
+
+	platform_set_drvdata(dev, p);
+
+	return 0;
+}
+
+static int __devexit parisc_rtc_remove(struct platform_device *dev)
+{
+	struct parisc_rtc *p = platform_get_drvdata(dev);
+
+	rtc_device_unregister(p->rtc);
+	kfree(p);
+
+	return 0;
+}
+
+static struct platform_driver parisc_rtc_driver = {
+	.driver = {
+		.name = "rtc-parisc",
+		.owner = THIS_MODULE,
+	},
+	.probe = parisc_rtc_probe,
+	.remove = __devexit_p(parisc_rtc_remove),
+};
+
+static int __init parisc_rtc_init(void)
+{
+	return platform_driver_register(&parisc_rtc_driver);
+}
+
+static void __exit parisc_rtc_fini(void)
+{
+	platform_driver_unregister(&parisc_rtc_driver);
+}
+
+module_init(parisc_rtc_init);
+module_exit(parisc_rtc_fini);
+
+MODULE_AUTHOR("Kyle McMartin <kyle@mcmartin.ca>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("HP PA-RISC RTC driver");