| // 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; | |
| } |