1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Intel BayTrail PMIC I2C bus semaphore implementation
4 * Copyright (c) 2014, Intel Corporation.
5 */
6#include <linux/device.h>
7#include <linux/acpi.h>
8#include <linux/i2c.h>
9#include <linux/interrupt.h>
10
11#include <asm/iosf_mbi.h>
12
13#include "i2c-designware-core.h"
14
15int i2c_dw_baytrail_probe_lock_support(struct dw_i2c_dev *dev)
16{
17	acpi_status status;
18	unsigned long long shared_host = 0;
19	acpi_handle handle;
20
21	if (!dev)
22		return -ENODEV;
23
24	handle = ACPI_HANDLE(dev->dev);
25	if (!handle)
26		return -ENODEV;
27
28	status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
29	if (ACPI_FAILURE(status))
30		return -ENODEV;
31
32	if (!shared_host)
33		return -ENODEV;
34
35	if (!iosf_mbi_available())
36		return -EPROBE_DEFER;
37
38	dev_info(dev->dev, "I2C bus managed by PUNIT\n");
39	dev->acquire_lock = iosf_mbi_block_punit_i2c_access;
40	dev->release_lock = iosf_mbi_unblock_punit_i2c_access;
41	dev->shared_with_punit = true;
42
43	return 0;
44}
45