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 000000000..c6a7a00e1
--- /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_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;
+}