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>

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..bd63621e37162b085bbf2f15c12f33b55b988022 100644 (file)
--- 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 fdcbc002953f4ea8f2a531b8dea3b63ed29c524e..61373b6fdb39c39cd10c214e2c7d346da12c8344 100644 (file)
--- 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 (file)
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,
+};

diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 395e25a43135835821b4c72cffaea2588d9ea352..08f1bad938589c07bac088da19d181566bd8de7e 100644 (file)
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -46,6 +46,7 @@ enum uclass_id {
        UCLASS_USB_DEV_GENERIC, /* USB generic device */
        UCLASS_MASS_STORAGE,    /* Mass storage device */
        UCLASS_CPU,             /* CPU, typically part of an SoC */
+       UCLASS_RTC,             /* Real time clock device */
 
        UCLASS_COUNT,
        UCLASS_INVALID = -1,

diff --git a/include/rtc.h b/include/rtc.h
index 2566c83b81d225036aec15a0cc8439cdbe5ff6b2..bd8621d60b93d4491d33ee477ccd04b7438c65a7 100644 (file)
--- 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