dm: rtc: Add a uclass for real-time clocks

Add a uclass for real-time clocks which support getting the current time,
setting it and resetting the chip to a known-working state. Some RTCs have
additional registers which can be used to store settings, so also provide
an interface to these.

Signed-off-by: Simon Glass <sjg@chromium.org>

3 files changed, 106 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index e69de29..bd63621 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -0,0 +1,8 @@
+config DM_RTC
+	bool "Enable Driver Model for RTC drivers"
+	depends on DM
+	help
+	  Enable drver model for real-time-clock drivers. The RTC uclass
+	  then provides the rtc_get()/rtc_set() interface, delegating to
+	  drivers to perform the actual functions. See rtc.h for a
+	  description of the API.
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index fdcbc00..61373b6 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -7,6 +7,8 @@
 
 #ccflags-y += -DDEBUG
 
+obj-$(CONFIG_DM_RTC) += rtc-uclass.o
+
 obj-$(CONFIG_RTC_AT91SAM9_RTT) += at91sam9_rtt.o
 obj-$(CONFIG_RTC_BFIN) += bfin_rtc.o
 obj-y += date.o
diff --git a/drivers/rtc/rtc-uclass.c b/drivers/rtc/rtc-uclass.c
new file mode 100644
index 0000000..fe74c69
--- /dev/null
+++ b/drivers/rtc/rtc-uclass.c
@@ -0,0 +1,96 @@
+/*
+ * (C) Copyright 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <rtc.h>
+
+int dm_rtc_get(struct udevice *dev, struct rtc_time *time)
+{
+	struct rtc_ops *ops = rtc_get_ops(dev);
+
+	assert(ops);
+	if (!ops->get)
+		return -ENOSYS;
+	return ops->get(dev, time);
+}
+
+int dm_rtc_set(struct udevice *dev, struct rtc_time *time)
+{
+	struct rtc_ops *ops = rtc_get_ops(dev);
+
+	assert(ops);
+	if (!ops->set)
+		return -ENOSYS;
+	return ops->set(dev, time);
+}
+
+int dm_rtc_reset(struct udevice *dev)
+{
+	struct rtc_ops *ops = rtc_get_ops(dev);
+
+	assert(ops);
+	if (!ops->reset)
+		return -ENOSYS;
+	return ops->reset(dev);
+}
+
+int rtc_read8(struct udevice *dev, unsigned int reg)
+{
+	struct rtc_ops *ops = rtc_get_ops(dev);
+
+	assert(ops);
+	if (!ops->read8)
+		return -ENOSYS;
+	return ops->read8(dev, reg);
+}
+
+int rtc_write8(struct udevice *dev, unsigned int reg, int val)
+{
+	struct rtc_ops *ops = rtc_get_ops(dev);
+
+	assert(ops);
+	if (!ops->write8)
+		return -ENOSYS;
+	return ops->write8(dev, reg, val);
+}
+
+int rtc_read32(struct udevice *dev, unsigned int reg, u32 *valuep)
+{
+	u32 value = 0;
+	int ret;
+	int i;
+
+	for (i = 0; i < sizeof(value); i++) {
+		ret = rtc_read8(dev, reg + i);
+		if (ret)
+			return ret;
+		value |= ret << (i << 3);
+	}
+
+	*valuep = value;
+	return 0;
+}
+
+int rtc_write32(struct udevice *dev, unsigned int reg, u32 value)
+{
+	int i, ret;
+
+	for (i = 0; i < sizeof(value); i++) {
+		ret = rtc_write8(dev, reg + i, (value >> (i << 3)) & 0xff);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+UCLASS_DRIVER(rtc) = {
+	.name		= "rtc",
+	.id		= UCLASS_RTC,
+};