diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-baytrail.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-baytrail.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c new file mode 100644 index 0000000000..45774aa47c --- /dev/null +++ b/drivers/i2c/busses/i2c-designware-baytrail.c @@ -0,0 +1,44 @@ +// 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_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; +} |