linux/drivers/firmware/arm_scmi/transports/mailbox.c

// SPDX-License-Identifier: GPL-2.0
/*
 * System Control and Management Interface (SCMI) Message Mailbox Transport
 * driver.
 *
 * Copyright (C) 2019-2024 ARM Ltd.
 */

#include <linux/err.h>
#include <linux/device.h>
#include <linux/mailbox_client.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include "../common.h"

/**
 * struct scmi_mailbox - Structure representing a SCMI mailbox transport
 *
 * @cl: Mailbox Client
 * @chan: Transmit/Receive mailbox uni/bi-directional channel
 * @chan_receiver: Optional Receiver mailbox unidirectional channel
 * @chan_platform_receiver: Optional Platform Receiver mailbox unidirectional channel
 * @cinfo: SCMI channel info
 * @shmem: Transmit/Receive shared memory area
 * @chan_lock: Lock that prevents multiple xfers from being queued
 */
struct scmi_mailbox { … };

#define client_to_scmi_mailbox(c) …

static struct scmi_transport_core_operations *core;

static void tx_prepare(struct mbox_client *cl, void *m)
{ … }

static void rx_callback(struct mbox_client *cl, void *m)
{ … }

static bool mailbox_chan_available(struct device_node *of_node, int idx)
{ … }

/**
 * mailbox_chan_validate  - Validate transport configuration and map channels
 *
 * @cdev: Reference to the underlying transport device carrying the
 *	  of_node descriptor to analyze.
 * @a2p_rx_chan: A reference to an optional unidirectional channel to use
 *		 for replies on the a2p channel. Set as zero if not present.
 * @p2a_chan: A reference to the optional p2a channel.
 *	      Set as zero if not present.
 * @p2a_rx_chan: A reference to the optional p2a completion channel.
 *	      Set as zero if not present.
 *
 * At first, validate the transport configuration as described in terms of
 * 'mboxes' and 'shmem', then determin which mailbox channel indexes are
 * appropriate to be use in the current configuration.
 *
 * Return: 0 on Success or error
 */
static int mailbox_chan_validate(struct device *cdev, int *a2p_rx_chan,
				 int *p2a_chan, int *p2a_rx_chan)
{ … }

static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
			      bool tx)
{ … }

static int mailbox_chan_free(int id, void *p, void *data)
{ … }

static int mailbox_send_message(struct scmi_chan_info *cinfo,
				struct scmi_xfer *xfer)
{ … }

static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret,
				struct scmi_xfer *__unused)
{ … }

static void mailbox_fetch_response(struct scmi_chan_info *cinfo,
				   struct scmi_xfer *xfer)
{ … }

static void mailbox_fetch_notification(struct scmi_chan_info *cinfo,
				       size_t max_len, struct scmi_xfer *xfer)
{ … }

static void mailbox_clear_channel(struct scmi_chan_info *cinfo)
{ … }

static bool
mailbox_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
{ … }

static const struct scmi_transport_ops scmi_mailbox_ops = …;

static struct scmi_desc scmi_mailbox_desc = …;

static const struct of_device_id scmi_of_match[] = …;

DEFINE_SCMI_TRANSPORT_DRIVER(scmi_mailbox, scmi_mailbox_driver,
			     scmi_mailbox_desc, scmi_of_match, core);
module_platform_driver(…) …;

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;