1 files changed, 78 insertions, 0 deletions
diff --git a/include/acpi/pcc.h b/include/acpi/pcc.h
new file mode 100644
index 000000000000..9af3b502f839
--- /dev/null
+++ b/include/acpi/pcc.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * PCC (Platform Communications Channel) methods
+ */
+
+#ifndef _PCC_H
+#define _PCC_H
+
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+
+struct pcc_mbox_chan {
+	struct mbox_chan *mchan;
+	u64 shmem_base_addr;
+	void __iomem *shmem;
+	u64 shmem_size;
+	u32 latency;
+	u32 max_access_rate;
+	u16 min_turnaround_time;
+
+	/* Set to true to indicate that the mailbox should manage
+	 * writing the dat to the shared buffer. This differs from
+	 * the case where the drivesr are writing to the buffer and
+	 * using send_data only to  ring the doorbell.  If this flag
+	 * is set, then the void * data parameter of send_data must
+	 * point to a kernel-memory buffer formatted in accordance with
+	 * the PCC specification.
+	 *
+	 * The active buffer management will include reading the
+	 * notify_on_completion flag, and will then
+	 * call mbox_chan_txdone when the acknowledgment interrupt is
+	 * received.
+	 */
+	bool manage_writes;
+
+	/* Optional callback that allows the driver
+	 * to allocate the memory used for receiving
+	 * messages.  The return value is the location
+	 * inside the buffer where the mailbox should write the data.
+	 */
+	void *(*rx_alloc)(struct mbox_client *cl,  int size);
+};
+
+struct pcc_header {
+	u32 signature;
+	u32 flags;
+	u32 length;
+	u32 command;
+};
+
+/* Generic Communications Channel Shared Memory Region */
+#define PCC_SIGNATURE			0x50434300
+/* Generic Communications Channel Command Field */
+#define PCC_CMD_GENERATE_DB_INTR	BIT(15)
+/* Generic Communications Channel Status Field */
+#define PCC_STATUS_CMD_COMPLETE		BIT(0)
+#define PCC_STATUS_SCI_DOORBELL		BIT(1)
+#define PCC_STATUS_ERROR		BIT(2)
+#define PCC_STATUS_PLATFORM_NOTIFY	BIT(3)
+/* Initiator Responder Communications Channel Flags */
+#define PCC_CMD_COMPLETION_NOTIFY	BIT(0)
+
+#define MAX_PCC_SUBSPACES	256
+
+#ifdef CONFIG_PCC
+extern struct pcc_mbox_chan *
+pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id);
+extern void pcc_mbox_free_channel(struct pcc_mbox_chan *chan);
+#else
+static inline struct pcc_mbox_chan *
+pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
+{
+	return ERR_PTR(-ENODEV);
+}
+static inline void pcc_mbox_free_channel(struct pcc_mbox_chan *chan) { }
+#endif
+
+#endif /* _PCC_H */