Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / arch / x86 / platform / mrst / vrtc.c

diff --git a/arch/x86/platform/mrst/vrtc.c b/arch/x86/platform/mrst/vrtc.c
new file mode 100644 (file)
index 0000000..32cd7ed
--- /dev/null
+++ b/arch/x86/platform/mrst/vrtc.c
@@ -0,0 +1,165 @@
+/*
+ * vrtc.c: Driver for virtual RTC device on Intel MID platform
+ *
+ * (C) Copyright 2009 Intel Corporation
+ *
+ * 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; version 2
+ * of the License.
+ *
+ * Note:
+ * VRTC is emulated by system controller firmware, the real HW
+ * RTC is located in the PMIC device. SCU FW shadows PMIC RTC
+ * in a memory mapped IO space that is visible to the host IA
+ * processor.
+ *
+ * This driver is based on RTC CMOS driver.
+ */
+
+#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>
+#include <asm/time.h>
+#include <asm/fixmap.h>
+
+static unsigned char __iomem *vrtc_virt_base;
+
+unsigned char vrtc_cmos_read(unsigned char reg)
+{
+       unsigned char retval;
+
+       /* vRTC's registers range from 0x0 to 0xD */
+       if (reg > 0xd || !vrtc_virt_base)
+               return 0xff;
+
+       lock_cmos_prefix(reg);
+       retval = __raw_readb(vrtc_virt_base + (reg << 2));
+       lock_cmos_suffix(reg);
+       return retval;
+}
+EXPORT_SYMBOL_GPL(vrtc_cmos_read);
+
+void vrtc_cmos_write(unsigned char val, unsigned char reg)
+{
+       if (reg > 0xd || !vrtc_virt_base)
+               return;
+
+       lock_cmos_prefix(reg);
+       __raw_writeb(val, vrtc_virt_base + (reg << 2));
+       lock_cmos_suffix(reg);
+}
+EXPORT_SYMBOL_GPL(vrtc_cmos_write);
+
+unsigned long vrtc_get_time(void)
+{
+       u8 sec, min, hour, mday, mon;
+       u32 year;
+
+       while ((vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP))
+               cpu_relax();
+
+       sec = vrtc_cmos_read(RTC_SECONDS);
+       min = vrtc_cmos_read(RTC_MINUTES);
+       hour = vrtc_cmos_read(RTC_HOURS);
+       mday = vrtc_cmos_read(RTC_DAY_OF_MONTH);
+       mon = vrtc_cmos_read(RTC_MONTH);
+       year = vrtc_cmos_read(RTC_YEAR);
+
+       /* vRTC YEAR reg contains the offset to 1960 */
+       year += 1960;
+
+       printk(KERN_INFO "vRTC: sec: %d min: %d hour: %d day: %d "
+               "mon: %d year: %d\n", sec, min, hour, mday, mon, year);
+
+       return mktime(year, mon, mday, hour, min, sec);
+}
+
+/* Only care about the minutes and seconds */
+int vrtc_set_mmss(unsigned long nowtime)
+{
+       int real_sec, real_min;
+       int vrtc_min;
+
+       vrtc_min = vrtc_cmos_read(RTC_MINUTES);
+
+       real_sec = nowtime % 60;
+       real_min = nowtime / 60;
+       if (((abs(real_min - vrtc_min) + 15)/30) & 1)
+               real_min += 30;
+       real_min %= 60;
+
+       vrtc_cmos_write(real_sec, RTC_SECONDS);
+       vrtc_cmos_write(real_min, RTC_MINUTES);
+       return 0;
+}
+
+void __init mrst_rtc_init(void)
+{
+       unsigned long rtc_paddr;
+       void __iomem *virt_base;
+
+       sfi_table_parse(SFI_SIG_MRTC, NULL, NULL, sfi_parse_mrtc);
+       if (!sfi_mrtc_num)
+               return;
+
+       rtc_paddr = sfi_mrtc_array[0].phys_addr;
+
+       /* vRTC's register address may not be page aligned */
+       set_fixmap_nocache(FIX_LNW_VRTC, rtc_paddr);
+
+       virt_base = (void __iomem *)__fix_to_virt(FIX_LNW_VRTC);
+       virt_base += rtc_paddr & ~PAGE_MASK;
+       vrtc_virt_base = virt_base;
+
+       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;
+
+       return platform_device_register(&vrtc_device);
+}
+
+module_init(mrst_device_create);