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 ---
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@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