1 files changed, 0 insertions, 329 deletions
diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c
deleted file mode 100644
index b8d470417e8f..000000000000
--- a/drivers/firmware/arm_scmi/mailbox.c
+++ /dev/null
@@ -1,329 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * System Control and Management Interface (SCMI) Message Mailbox Transport
- * driver.
- *
- * Copyright (C) 2019 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/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
- * @cinfo: SCMI channel info
- * @shmem: Transmit/Receive shared memory area
- */
-struct scmi_mailbox {
-	struct mbox_client cl;
-	struct mbox_chan *chan;
-	struct mbox_chan *chan_receiver;
-	struct scmi_chan_info *cinfo;
-	struct scmi_shared_mem __iomem *shmem;
-};
-
-#define client_to_scmi_mailbox(c) container_of(c, struct scmi_mailbox, cl)
-
-static void tx_prepare(struct mbox_client *cl, void *m)
-{
-	struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
-
-	shmem_tx_prepare(smbox->shmem, m, smbox->cinfo);
-}
-
-static void rx_callback(struct mbox_client *cl, void *m)
-{
-	struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
-
-	/*
-	 * An A2P IRQ is NOT valid when received while the platform still has
-	 * the ownership of the channel, because the platform at first releases
-	 * the SMT channel and then sends the completion interrupt.
-	 *
-	 * This addresses a possible race condition in which a spurious IRQ from
-	 * a previous timed-out reply which arrived late could be wrongly
-	 * associated with the next pending transaction.
-	 */
-	if (cl->knows_txdone && !shmem_channel_free(smbox->shmem)) {
-		dev_warn(smbox->cinfo->dev, "Ignoring spurious A2P IRQ !\n");
-		return;
-	}
-
-	scmi_rx_callback(smbox->cinfo, shmem_read_header(smbox->shmem), NULL);
-}
-
-static bool mailbox_chan_available(struct device_node *of_node, int idx)
-{
-	int num_mb;
-
-	/*
-	 * Just check if bidirrectional channels are involved, and check the
-	 * index accordingly; proper full validation will be made later
-	 * in mailbox_chan_setup().
-	 */
-	num_mb = of_count_phandle_with_args(of_node, "mboxes", "#mbox-cells");
-	if (num_mb == 3 && idx == 1)
-		idx = 2;
-
-	return !of_parse_phandle_with_args(of_node, "mboxes",
-					   "#mbox-cells", idx, NULL);
-}
-
-/**
- * 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.
- *
- * 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 num_mb, num_sh, ret = 0;
-	struct device_node *np = cdev->of_node;
-
-	num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
-	num_sh = of_count_phandle_with_args(np, "shmem", NULL);
-	dev_dbg(cdev, "Found %d mboxes and %d shmems !\n", num_mb, num_sh);
-
-	/* Bail out if mboxes and shmem descriptors are inconsistent */
-	if (num_mb <= 0 || num_sh <= 0 || num_sh > 2 || num_mb > 3 ||
-	    (num_mb == 1 && num_sh != 1) || (num_mb == 3 && num_sh != 2)) {
-		dev_warn(cdev,
-			 "Invalid channel descriptor for '%s' - mbs:%d  shm:%d\n",
-			 of_node_full_name(np), num_mb, num_sh);
-		return -EINVAL;
-	}
-
-	/* Bail out if provided shmem descriptors do not refer distinct areas  */
-	if (num_sh > 1) {
-		struct device_node *np_tx, *np_rx;
-
-		np_tx = of_parse_phandle(np, "shmem", 0);
-		np_rx = of_parse_phandle(np, "shmem", 1);
-		if (!np_tx || !np_rx || np_tx == np_rx) {
-			dev_warn(cdev, "Invalid shmem descriptor for '%s'\n",
-				 of_node_full_name(np));
-			ret = -EINVAL;
-		}
-
-		of_node_put(np_tx);
-		of_node_put(np_rx);
-	}
-
-	/* Calculate channels IDs to use depending on mboxes/shmem layout */
-	if (!ret) {
-		switch (num_mb) {
-		case 1:
-			*a2p_rx_chan = 0;
-			*p2a_chan = 0;
-			break;
-		case 2:
-			if (num_sh == 2) {
-				*a2p_rx_chan = 0;
-				*p2a_chan = 1;
-			} else {
-				*a2p_rx_chan = 1;
-				*p2a_chan = 0;
-			}
-			break;
-		case 3:
-			*a2p_rx_chan = 1;
-			*p2a_chan = 2;
-			break;
-		}
-	}
-
-	return ret;
-}
-
-static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
-			      bool tx)
-{
-	const char *desc = tx ? "Tx" : "Rx";
-	struct device *cdev = cinfo->dev;
-	struct scmi_mailbox *smbox;
-	struct device_node *shmem;
-	int ret, a2p_rx_chan, p2a_chan, idx = tx ? 0 : 1;
-	struct mbox_client *cl;
-	resource_size_t size;
-	struct resource res;
-
-	ret = mailbox_chan_validate(cdev, &a2p_rx_chan, &p2a_chan);
-	if (ret)
-		return ret;
-
-	if (!tx && !p2a_chan)
-		return -ENODEV;
-
-	smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL);
-	if (!smbox)
-		return -ENOMEM;
-
-	shmem = of_parse_phandle(cdev->of_node, "shmem", idx);
-	if (!of_device_is_compatible(shmem, "arm,scmi-shmem")) {
-		of_node_put(shmem);
-		return -ENXIO;
-	}
-
-	ret = of_address_to_resource(shmem, 0, &res);
-	of_node_put(shmem);
-	if (ret) {
-		dev_err(cdev, "failed to get SCMI %s shared memory\n", desc);
-		return ret;
-	}
-
-	size = resource_size(&res);
-	smbox->shmem = devm_ioremap(dev, res.start, size);
-	if (!smbox->shmem) {
-		dev_err(dev, "failed to ioremap SCMI %s shared memory\n", desc);
-		return -EADDRNOTAVAIL;
-	}
-
-	cl = &smbox->cl;
-	cl->dev = cdev;
-	cl->tx_prepare = tx ? tx_prepare : NULL;
-	cl->rx_callback = rx_callback;
-	cl->tx_block = false;
-	cl->knows_txdone = tx;
-
-	smbox->chan = mbox_request_channel(cl, tx ? 0 : p2a_chan);
-	if (IS_ERR(smbox->chan)) {
-		ret = PTR_ERR(smbox->chan);
-		if (ret != -EPROBE_DEFER)
-			dev_err(cdev,
-				"failed to request SCMI %s mailbox\n", desc);
-		return ret;
-	}
-
-	/* Additional unidirectional channel for TX if needed */
-	if (tx && a2p_rx_chan) {
-		smbox->chan_receiver = mbox_request_channel(cl, a2p_rx_chan);
-		if (IS_ERR(smbox->chan_receiver)) {
-			ret = PTR_ERR(smbox->chan_receiver);
-			if (ret != -EPROBE_DEFER)
-				dev_err(cdev, "failed to request SCMI Tx Receiver mailbox\n");
-			return ret;
-		}
-	}
-
-	cinfo->transport_info = smbox;
-	smbox->cinfo = cinfo;
-
-	return 0;
-}
-
-static int mailbox_chan_free(int id, void *p, void *data)
-{
-	struct scmi_chan_info *cinfo = p;
-	struct scmi_mailbox *smbox = cinfo->transport_info;
-
-	if (smbox && !IS_ERR(smbox->chan)) {
-		mbox_free_channel(smbox->chan);
-		mbox_free_channel(smbox->chan_receiver);
-		cinfo->transport_info = NULL;
-		smbox->chan = NULL;
-		smbox->chan_receiver = NULL;
-		smbox->cinfo = NULL;
-	}
-
-	return 0;
-}
-
-static int mailbox_send_message(struct scmi_chan_info *cinfo,
-				struct scmi_xfer *xfer)
-{
-	struct scmi_mailbox *smbox = cinfo->transport_info;
-	int ret;
-
-	ret = mbox_send_message(smbox->chan, xfer);
-
-	/* mbox_send_message returns non-negative value on success, so reset */
-	if (ret > 0)
-		ret = 0;
-
-	return ret;
-}
-
-static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret,
-				struct scmi_xfer *__unused)
-{
-	struct scmi_mailbox *smbox = cinfo->transport_info;
-
-	/*
-	 * NOTE: we might prefer not to need the mailbox ticker to manage the
-	 * transfer queueing since the protocol layer queues things by itself.
-	 * Unfortunately, we have to kick the mailbox framework after we have
-	 * received our message.
-	 */
-	mbox_client_txdone(smbox->chan, ret);
-}
-
-static void mailbox_fetch_response(struct scmi_chan_info *cinfo,
-				   struct scmi_xfer *xfer)
-{
-	struct scmi_mailbox *smbox = cinfo->transport_info;
-
-	shmem_fetch_response(smbox->shmem, xfer);
-}
-
-static void mailbox_fetch_notification(struct scmi_chan_info *cinfo,
-				       size_t max_len, struct scmi_xfer *xfer)
-{
-	struct scmi_mailbox *smbox = cinfo->transport_info;
-
-	shmem_fetch_notification(smbox->shmem, max_len, xfer);
-}
-
-static void mailbox_clear_channel(struct scmi_chan_info *cinfo)
-{
-	struct scmi_mailbox *smbox = cinfo->transport_info;
-
-	shmem_clear_channel(smbox->shmem);
-}
-
-static bool
-mailbox_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
-{
-	struct scmi_mailbox *smbox = cinfo->transport_info;
-
-	return shmem_poll_done(smbox->shmem, xfer);
-}
-
-static const struct scmi_transport_ops scmi_mailbox_ops = {
-	.chan_available = mailbox_chan_available,
-	.chan_setup = mailbox_chan_setup,
-	.chan_free = mailbox_chan_free,
-	.send_message = mailbox_send_message,
-	.mark_txdone = mailbox_mark_txdone,
-	.fetch_response = mailbox_fetch_response,
-	.fetch_notification = mailbox_fetch_notification,
-	.clear_channel = mailbox_clear_channel,
-	.poll_done = mailbox_poll_done,
-};
-
-const struct scmi_desc scmi_mailbox_desc = {
-	.ops = &scmi_mailbox_ops,
-	.max_rx_timeout_ms = 30, /* We may increase this if required */
-	.max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */
-	.max_msg_size = 128,
-};