rtc: Add drivers/rtc/rtc-mrst.c

Provide the standard kernel rtc driver interface on top of the vrtc layer
added in the previous patch.

Signed-off-by: Feng Tang <feng.tang@intel.com>
LKML-Reference: <20101110172911.3311.20593.stgit@localhost.localdomain>
[Fixed swapped arguments on IPC]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
[Cleaned up and the device creation moved to arch/x86/platform]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/platform/mrst/vrtc.c

@@ -20,6 +20,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/sfi.h>
+#include <linux/platform_device.h>
 
 #include <asm/mrst.h>
 #include <asm/mrst-vrtc.h>
@@ -118,3 +119,48 @@ void __init mrst_rtc_init(void)
 	x86_platform.get_wallclock = vrtc_get_time;
 	x86_platform.set_wallclock = vrtc_set_mmss;
 }
+
+/*
+ * The Moorestown platform has a memory mapped virtual RTC device that emulates
+ * the programming interface of the RTC.
+ */
+
+static struct resource vrtc_resources[] = {
+	[0] = {
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.flags	= IORESOURCE_IRQ,
+	}
+};
+
+static struct platform_device vrtc_device = {
+	.name		= "rtc_mrst",
+	.id		= -1,
+	.resource	= vrtc_resources,
+	.num_resources	= ARRAY_SIZE(vrtc_resources),
+};
+
+/* Register the RTC device if appropriate */
+static int __init mrst_device_create(void)
+{
+	/* No Moorestown, no device */
+	if (!mrst_identify_cpu())
+		return -ENODEV;
+	/* No timer, no device */
+	if (!sfi_mrtc_num)
+		return -ENODEV;
+
+	/* iomem resource */
+	vrtc_resources[0].start = sfi_mrtc_array[0].phys_addr;
+	vrtc_resources[0].end = sfi_mrtc_array[0].phys_addr +
+				MRST_VRTC_MAP_SZ;
+	/* irq resource */
+	vrtc_resources[1].start = sfi_mrtc_array[0].irq;
+	vrtc_resources[1].end = sfi_mrtc_array[0].irq;
+
+	platform_device_register(&vrtc_device);
+	return 0;
+}
+
+module_init(mrst_device_create);

drivers/rtc/Kconfig

@@ -463,6 +463,18 @@ config RTC_DRV_CMOS
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-cmos.
 
+config RTC_DRV_VRTC
+	tristate "Virtual RTC for Moorestown platforms"
+	depends on X86_MRST
+	default y if X86_MRST
+
+	help
+	Say "yes" here to get direct support for the real time clock
+	found on Moorestown platforms. The VRTC is a emulated RTC that
+	derives its clock source from a real RTC in the PMIC. The MC146818
+	style programming interface is mostly conserved, but any
+	updates are done via IPC calls to the system controller FW.
+
 config RTC_DRV_DS1216
 	tristate "Dallas DS1216"
 	depends on SNI_RM

drivers/rtc/Makefile

@@ -30,6 +30,7 @@ obj-$(CONFIG_RTC_DRV_CMOS)	+= rtc-cmos.o
 obj-$(CONFIG_RTC_DRV_COH901331)	+= rtc-coh901331.o
 obj-$(CONFIG_RTC_DRV_DAVINCI)	+= rtc-davinci.o
 obj-$(CONFIG_RTC_DRV_DM355EVM)	+= rtc-dm355evm.o
+obj-$(CONFIG_RTC_DRV_VRTC)	+= rtc-mrst.o
 obj-$(CONFIG_RTC_DRV_DS1216)	+= rtc-ds1216.o
 obj-$(CONFIG_RTC_DRV_DS1286)	+= rtc-ds1286.o
 obj-$(CONFIG_RTC_DRV_DS1302)	+= rtc-ds1302.o