blob: c6a7a00e1d5296ae126c0d804856a10d1e8832dc (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
// 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_probe_lock_support(struct dw_i2c_dev *dev)
{
acpi_status status;
unsigned long long shared_host = 0;
acpi_handle handle;
if (!dev || !dev->dev)
return 0;
handle = ACPI_HANDLE(dev->dev);
if (!handle)
return 0;
status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
if (ACPI_FAILURE(status))
return 0;
if (!shared_host)
return 0;
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;
}
|
