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>
This commit is contained in:
Simon Glass 2015-04-20 12:37:23 -06:00
parent 94eefdee2f
commit dbeda5b225
5 changed files with 239 additions and 0 deletions

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@ -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.

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@ -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

96
drivers/rtc/rtc-uclass.c Normal file
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@ -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,
};

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@ -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,

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@ -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