1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * Intel BayTrail PMIC I2C bus semaphore implementation 4*4882a593Smuzhiyun * Copyright (c) 2014, Intel Corporation. 5*4882a593Smuzhiyun */ 6*4882a593Smuzhiyun #include <linux/device.h> 7*4882a593Smuzhiyun #include <linux/acpi.h> 8*4882a593Smuzhiyun #include <linux/i2c.h> 9*4882a593Smuzhiyun #include <linux/interrupt.h> 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun #include <asm/iosf_mbi.h> 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun #include "i2c-designware-core.h" 14*4882a593Smuzhiyun i2c_dw_probe_lock_support(struct dw_i2c_dev * dev)15*4882a593Smuzhiyunint i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) 16*4882a593Smuzhiyun { 17*4882a593Smuzhiyun acpi_status status; 18*4882a593Smuzhiyun unsigned long long shared_host = 0; 19*4882a593Smuzhiyun acpi_handle handle; 20*4882a593Smuzhiyun 21*4882a593Smuzhiyun if (!dev || !dev->dev) 22*4882a593Smuzhiyun return 0; 23*4882a593Smuzhiyun 24*4882a593Smuzhiyun handle = ACPI_HANDLE(dev->dev); 25*4882a593Smuzhiyun if (!handle) 26*4882a593Smuzhiyun return 0; 27*4882a593Smuzhiyun 28*4882a593Smuzhiyun status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host); 29*4882a593Smuzhiyun if (ACPI_FAILURE(status)) 30*4882a593Smuzhiyun return 0; 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun if (!shared_host) 33*4882a593Smuzhiyun return 0; 34*4882a593Smuzhiyun 35*4882a593Smuzhiyun if (!iosf_mbi_available()) 36*4882a593Smuzhiyun return -EPROBE_DEFER; 37*4882a593Smuzhiyun 38*4882a593Smuzhiyun dev_info(dev->dev, "I2C bus managed by PUNIT\n"); 39*4882a593Smuzhiyun dev->acquire_lock = iosf_mbi_block_punit_i2c_access; 40*4882a593Smuzhiyun dev->release_lock = iosf_mbi_unblock_punit_i2c_access; 41*4882a593Smuzhiyun dev->shared_with_punit = true; 42*4882a593Smuzhiyun 43*4882a593Smuzhiyun return 0; 44*4882a593Smuzhiyun } 45