[U-Boot] [PATCH 12/20] dm: rtc: Add a uclass for real-time clocks
Simon Glass
sjg at chromium.org
Mon Apr 20 20:37:23 CEST 2015
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 at chromium.org>
---
drivers/rtc/Kconfig | 8 +++
drivers/rtc/Makefile | 2 +
drivers/rtc/rtc-uclass.c | 96 ++++++++++++++++++++++++++++++++++
include/dm/uclass-id.h | 1 +
include/rtc.h | 132 +++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 239 insertions(+)
create mode 100644 drivers/rtc/rtc-uclass.c
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 at 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,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index fddfd35..92a2e4f 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -45,6 +45,7 @@ enum uclass_id {
UCLASS_USB_HUB, /* USB hub */
UCLASS_USB_DEV_GENERIC, /* USB generic device */
UCLASS_MASS_STORAGE, /* Mass storage device */
+ UCLASS_RTC, /* Real time clock device */
UCLASS_COUNT,
UCLASS_INVALID = -1,
diff --git a/include/rtc.h b/include/rtc.h
index 2566c83..bd8621d 100644
--- a/include/rtc.h
+++ b/include/rtc.h
@@ -17,6 +17,137 @@
#include <bcd.h>
#include <rtc_def.h>
+#ifdef CONFIG_DM_RTC
+
+struct rtc_ops {
+ /**
+ * get() - get the current time
+ *
+ * Returns the current time read from the RTC device. The driver
+ * is responsible for setting up every field in the structure.
+ *
+ * @dev: Device to read from
+ * @time: Place to put the time that is read
+ */
+ int (*get)(struct udevice *dev, struct rtc_time *time);
+
+ /**
+ * set() - set the current time
+ *
+ * Sets the time in the RTC device. The driver can expect every
+ * field to be set correctly.
+ *
+ * @dev: Device to read from
+ * @time: Time to write
+ */
+ int (*set)(struct udevice *dev, const struct rtc_time *time);
+
+ /**
+ * reset() - reset the RTC to a known-good state
+ *
+ * This function resets the RTC to a known-good state. The time may
+ * be unset by this method, so should be set after this method is
+ * called.
+ *
+ * @dev: Device to read from
+ * @return 0 if OK, -ve on error
+ */
+ int (*reset)(struct udevice *dev);
+
+ /**
+ * read8() - Read an 8-bit register
+ *
+ * @dev: Device to read from
+ * @reg: Register to read
+ * @return value read, or -ve on error
+ */
+ int (*read8)(struct udevice *dev, unsigned int reg);
+
+ /**
+ * write8() - Write an 8-bit register
+ *
+ * @dev: Device to write to
+ * @reg: Register to write
+ * @value: Value to write
+ * @return 0 if OK, -ve on error
+ */
+ int (*write8)(struct udevice *dev, unsigned int reg, int val);
+};
+
+/* Access the operations for an RTC device */
+#define rtc_get_ops(dev) ((struct rtc_ops *)(dev)->driver->ops)
+
+/**
+ * dm_rtc_get() - Read the time from an RTC
+ *
+ * @dev: Device to read from
+ * @time: Place to put the current time
+ * @return 0 if OK, -ve on error
+ */
+int dm_rtc_get(struct udevice *dev, struct rtc_time *time);
+
+/**
+ * dm_rtc_put() - Write a time to an RTC
+ *
+ * @dev: Device to read from
+ * @time: Time to write into the RTC
+ * @return 0 if OK, -ve on error
+ */
+int dm_rtc_set(struct udevice *dev, struct rtc_time *time);
+
+/**
+ * dm_rtc_reset() - reset the RTC to a known-good state
+ *
+ * If the RTC appears to be broken (e.g. it is not counting up in seconds)
+ * it may need to be reset to a known good state. This function achieves this.
+ * After resetting the RTC the time should then be set to a known value by
+ * the caller.
+ *
+ * @dev: Device to read from
+ * @return 0 if OK, -ve on error
+ */
+int dm_rtc_reset(struct udevice *dev);
+
+/**
+ * rtc_read8() - Read an 8-bit register
+ *
+ * @dev: Device to read from
+ * @reg: Register to read
+ * @return value read, or -ve on error
+ */
+int rtc_read8(struct udevice *dev, unsigned int reg);
+
+/**
+ * rtc_write8() - Write an 8-bit register
+ *
+ * @dev: Device to write to
+ * @reg: Register to write
+ * @value: Value to write
+ * @return 0 if OK, -ve on error
+ */
+int rtc_write8(struct udevice *dev, unsigned int reg, int val);
+
+/**
+ * rtc_read32() - Read a 32-bit value from the RTC
+ *
+ * @dev: Device to read from
+ * @reg: Offset to start reading from
+ * @valuep: Place to put the value that is read
+ * @return 0 if OK, -ve on error
+ */
+int rtc_read32(struct udevice *dev, unsigned int reg, u32 *valuep);
+
+/**
+ * rtc_write32() - Write a 32-bit value to the RTC
+ *
+ * @dev: Device to write to
+ * @reg: Register to start writing to
+ * @value: Value to write
+ * @return 0 if OK, -ve on error
+ */
+int rtc_write32(struct udevice *dev, unsigned int reg, u32 value);
+
+#else
int rtc_get (struct rtc_time *);
int rtc_set (struct rtc_time *);
void rtc_reset (void);
@@ -57,6 +188,7 @@ void rtc_write32(int reg, u32 value);
* rtc_init() - Set up the real time clock ready for use
*/
void rtc_init(void);
+#endif
/**
* rtc_calc_weekday() - Work out the weekday from a time
--
2.2.0.rc0.207.ga3a616c
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