forked from Imagelibrary/rtems
38dd86355d
The MCP7940M is a I2C RTC chip. The new driver uses the dev/i2c API to support the RTC. It is written with the intention, that the driver can be adapted to other RTCs with a similar register layout by just replacing the initialization function.
104 lines
3.3 KiB
C
104 lines
3.3 KiB
C
/* SPDX-License-Identifier: BSD-2-Clause */
|
|
|
|
/*
|
|
* Copyright (C) 2023 embedded brains GmbH & Co. KG
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef LIBCHIP_MCP7940M_RTC_H
|
|
#define LIBCHIP_MCP7940M_RTC_H
|
|
|
|
#include <rtems.h>
|
|
#include <rtems/thread.h>
|
|
#include <libchip/rtc.h>
|
|
#include <stdint.h>
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif /* __cplusplus */
|
|
|
|
extern const rtc_fns rtc_mcp7940m_fns;
|
|
bool rtc_mcp7940m_probe(int minor);
|
|
|
|
/*
|
|
* It is expected, that the RTC can be accessed as a raw file. A pointer to a
|
|
* constant string with the name of that device has to be passed to the table
|
|
* initializer.
|
|
*
|
|
* The MCP7940M uses an EEPROM-like interface. So you could for example use the
|
|
* following initialization:
|
|
*
|
|
* Define a context for the RTC somewhere:
|
|
*
|
|
* static struct mcp7940m_rtc rtc_ctx =
|
|
* MCP7940M_RTC_INITIALIZER("/dev/i2c-1", 0x6F, true);
|
|
*
|
|
* Then you can use the following for the RTC_Table:
|
|
*
|
|
* MCP7940M_RTC_TBL_ENTRY("/dev/rtc", &rtc_ctx)
|
|
*/
|
|
|
|
struct mcp7940m_rtc {
|
|
/** Just initialize with RTEMS_MUTEX_INITIALIZER('mcp7940'). */
|
|
rtems_mutex mutex;
|
|
|
|
/** The path of the I2C bus device. */
|
|
const char *i2c_bus_path;
|
|
|
|
/** I2C address. */
|
|
uint8_t i2c_addr;
|
|
|
|
/** True if a crystal should be used. False if an oscillator is connected. */
|
|
bool crystal;
|
|
|
|
/** Whether the RTC has already been initialized. Used internally. */
|
|
bool initialized;
|
|
};
|
|
|
|
#define MCP7940M_RTC_INITIALIZER(i2c_path, i2c_address, has_crystal) { \
|
|
.mutex = RTEMS_MUTEX_INITIALIZER("mcp7940m"), \
|
|
.i2c_bus_path = i2c_path, \
|
|
.i2c_addr = i2c_address, \
|
|
.crystal = has_crystal, \
|
|
.initialized = false, \
|
|
}
|
|
|
|
#define MCP7940M_RTC_TBL_ENTRY(dev_name, mcp7940m_rtc_ctx) \
|
|
{ \
|
|
.sDeviceName = dev_name, \
|
|
.deviceType = RTC_CUSTOM, \
|
|
.pDeviceFns = &rtc_mcp7940m_fns, \
|
|
.deviceProbe = rtc_mcp7940m_probe, \
|
|
.pDeviceParams = (void *)mcp7940m_rtc_ctx, \
|
|
.ulCtrlPort1 = 0, \
|
|
.ulDataPort = 0, \
|
|
.getRegister = NULL, \
|
|
.setRegister = NULL, \
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif /* __cplusplus */
|
|
|
|
#endif /* LIBCHIP_MCP7940M_RTC_H */
|