[PATCH 10/11] x86, olpc: Add XO-1 RTC driver

From: Daniel Drake
Date: Sat Apr 30 2011 - 08:54:31 EST

Add a driver to configure the XO-1 RTC via CS5536 MSRs, to be used as a
system wakeup source via olpc-xo1-pm.

Device detection is based on finding the relevant device tree node.

Signed-off-by: Daniel Drake <dsd@xxxxxxxxxx>
Cc: devicetree-discuss@xxxxxxxxxxxxxxxx
---
.../devicetree/bindings/rtc/olpc-xo1-rtc.txt | 5 +
arch/x86/Kconfig | 7 ++
arch/x86/platform/olpc/Makefile | 1 +
arch/x86/platform/olpc/olpc-xo1-rtc.c | 82 ++++++++++++++++++++
include/linux/cs5535.h | 5 +
5 files changed, 100 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/rtc/olpc-xo1-rtc.txt
create mode 100644 arch/x86/platform/olpc/olpc-xo1-rtc.c

diff --git a/Documentation/devicetree/bindings/rtc/olpc-xo1-rtc.txt b/Documentation/devicetree/bindings/rtc/olpc-xo1-rtc.txt
new file mode 100644
index 0000000..a2891ce
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/olpc-xo1-rtc.txt
@@ -0,0 +1,5 @@
+OLPC XO-1 RTC
+~~~~~~~~~~~~~
+
+Required properties:
+ - compatible : "olpc,xo1-rtc"
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 583e1c5..eb9f377 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2072,6 +2072,13 @@ config OLPC_XO1_PM
---help---
Add support for poweroff and suspend of the OLPC XO-1 laptop.

+config OLPC_XO1_RTC
+ bool "OLPC XO-1 Real Time Clock"
+ depends on OLPC_XO1_PM && RTC_DRV_CMOS
+ ---help---
+ Add support for the XO-1 real time clock, which can be used as a
+ programmable wakeup source.
+
config OLPC_XO1_SCI
bool "OLPC XO-1 SCI extras"
depends on OLPC && OLPC_XO1_PM && POWER_SUPPLY
diff --git a/arch/x86/platform/olpc/Makefile b/arch/x86/platform/olpc/Makefile
index 1ec5ade..8922b9b 100644
--- a/arch/x86/platform/olpc/Makefile
+++ b/arch/x86/platform/olpc/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_OLPC) += olpc.o olpc_ofw.o olpc_dt.o
obj-$(CONFIG_OLPC_XO1_PM) += olpc-xo1-pm.o xo1-wakeup.o
+obj-$(CONFIG_OLPC_XO1_RTC) += olpc-xo1-rtc.o
obj-$(CONFIG_OLPC_XO1_SCI) += olpc-xo1-sci.o
diff --git a/arch/x86/platform/olpc/olpc-xo1-rtc.c b/arch/x86/platform/olpc/olpc-xo1-rtc.c
new file mode 100644
index 0000000..476cc98
--- /dev/null
+++ b/arch/x86/platform/olpc/olpc-xo1-rtc.c
@@ -0,0 +1,82 @@
+/*
+ * Support for OLPC XO-1 Real Time Clock (RTC)
+ *
+ * Copyright (C) 2011 One Laptop per Child
+ *
+ * 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/mc146818rtc.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/of.h>
+
+#include <asm/msr.h>
+#include <asm/olpc.h>
+
+static void rtc_wake_on(struct device *dev)
+{
+ olpc_xo1_pm_wakeup_set(CS5536_PM_RTC);
+}
+
+static void rtc_wake_off(struct device *dev)
+{
+ olpc_xo1_pm_wakeup_clear(CS5536_PM_RTC);
+}
+
+static struct resource rtc_platform_resource[] = {
+ [0] = {
+ .start = RTC_PORT(0),
+ .end = RTC_PORT(1),
+ .flags = IORESOURCE_IO,
+ },
+ [1] = {
+ .start = RTC_IRQ,
+ .end = RTC_IRQ,
+ .flags = IORESOURCE_IRQ,
+ }
+};
+
+static struct cmos_rtc_board_info rtc_info = {
+ .rtc_day_alarm = 0,
+ .rtc_mon_alarm = 0,
+ .rtc_century = 0,
+ .wake_on = rtc_wake_on,
+ .wake_off = rtc_wake_off,
+};
+
+static struct platform_device xo1_rtc_device = {
+ .name = "rtc_cmos",
+ .id = -1,
+ .num_resources = ARRAY_SIZE(rtc_platform_resource),
+ .dev.platform_data = &rtc_info,
+ .resource = rtc_platform_resource,
+};
+
+static int __init xo1_rtc_init(void)
+{
+ int r;
+ struct device_node *node;
+
+ node = of_find_compatible_node(NULL, NULL, "olpc,xo1-rtc");
+ if (!node)
+ return 0;
+ of_node_put(node);
+
+ pr_info("olpc-xo1-rtc: Initializing OLPC XO-1 RTC\n");
+ rdmsrl(MSR_RTC_DOMA_OFFSET, rtc_info.rtc_day_alarm);
+ rdmsrl(MSR_RTC_MONA_OFFSET, rtc_info.rtc_mon_alarm);
+ rdmsrl(MSR_RTC_CEN_OFFSET, rtc_info.rtc_century);
+
+ r = platform_device_register(&xo1_rtc_device);
+ if (r)
+ return r;
+
+ device_init_wakeup(&xo1_rtc_device.dev, 1);
+ return 0;
+}
+arch_initcall(xo1_rtc_init);
+
diff --git a/include/linux/cs5535.h b/include/linux/cs5535.h
index f2b4a2f..3f98d81 100644
--- a/include/linux/cs5535.h
+++ b/include/linux/cs5535.h
@@ -38,6 +38,10 @@
#define MSR_MFGPT_NR 0x51400029
#define MSR_MFGPT_SETUP 0x5140002B

+#define MSR_RTC_DOMA_OFFSET 0x51400055
+#define MSR_RTC_MONA_OFFSET 0x51400056
+#define MSR_RTC_CEN_OFFSET 0x51400057
+
#define MSR_LX_SPARE_MSR 0x80000011 /* DC-specific */

#define MSR_GX_GLD_MSR_CONFIG 0xC0002001
@@ -81,6 +85,7 @@

/* CS5536_PM1_EN bits */
#define CS5536_PM_PWRBTN (1 << 8)
+#define CS5536_PM_RTC (1 << 10)

/* CS5536_PM_GPE0_STS bits */
#define CS5536_GPIOM7_PME_FLAG (1 << 31)
--
1.7.4.4

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