// 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; }