45 lines
959 B
C
45 lines
959 B
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Intel BayTrail PMIC I2C bus semaphore implementation
|
|
* Copyright (c) 2014, Intel Corporation.
|
|
*/
|
|
#include <linux/device.h>
|
|
#include <linux/acpi.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/interrupt.h>
|
|
|
|
#include <asm/iosf_mbi.h>
|
|
|
|
#include "i2c-designware-core.h"
|
|
|
|
int i2c_dw_baytrail_probe_lock_support(struct dw_i2c_dev *dev)
|
|
{
|
|
acpi_status status;
|
|
unsigned long long shared_host = 0;
|
|
acpi_handle handle;
|
|
|
|
if (!dev)
|
|
return -ENODEV;
|
|
|
|
handle = ACPI_HANDLE(dev->dev);
|
|
if (!handle)
|
|
return -ENODEV;
|
|
|
|
status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
|
|
if (ACPI_FAILURE(status))
|
|
return -ENODEV;
|
|
|
|
if (!shared_host)
|
|
return -ENODEV;
|
|
|
|
if (!iosf_mbi_available())
|
|
return -EPROBE_DEFER;
|
|
|
|
dev_info(dev->dev, "I2C bus managed by PUNIT\n");
|
|
dev->acquire_lock = iosf_mbi_block_punit_i2c_access;
|
|
dev->release_lock = iosf_mbi_unblock_punit_i2c_access;
|
|
dev->shared_with_punit = true;
|
|
|
|
return 0;
|
|
}
|