1 // SPDX-License-Identifier: GPL-2.0
3  * System Control and Management Interface (SCMI) Message Mailbox Transport
19  * struct scmi_mailbox - Structure representing a SCMI mailbox transport
23  * @cinfo: SCMI channel info
24  * @shmem: Transmit/Receive shared memory area
30 	struct scmi_shared_mem __iomem *shmem;  member
39 	shmem_tx_prepare(smbox->shmem, m);  in tx_prepare()
52 	 * a previous timed-out reply which arrived late could be wrongly  in rx_callback()
55 	if (cl->knows_txdone && !shmem_channel_free(smbox->shmem)) {  in rx_callback()
56 		dev_warn(smbox->cinfo->dev, "Ignoring spurious A2P IRQ !\n");  in rx_callback()
60 	scmi_rx_callback(smbox->cinfo, shmem_read_header(smbox->shmem));  in rx_callback()
65 	return !of_parse_phandle_with_args(dev->of_node, "mboxes",  in mailbox_chan_available()
66 					   "#mbox-cells", idx, NULL);  in mailbox_chan_available()
72 	struct device_node *np = cdev->of_node;  in mailbox_chan_validate()
74 	num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");  in mailbox_chan_validate()
75 	num_sh = of_count_phandle_with_args(np, "shmem", NULL);  in mailbox_chan_validate()
76 	/* Bail out if mboxes and shmem descriptors are inconsistent */  in mailbox_chan_validate()
80 		return -EINVAL;  in mailbox_chan_validate()
86 		np_tx = of_parse_phandle(np, "shmem", 0);  in mailbox_chan_validate()
87 		np_rx = of_parse_phandle(np, "shmem", 1);  in mailbox_chan_validate()
88 		/* SCMI Tx and Rx shared mem areas have to be distinct */  in mailbox_chan_validate()
90 			dev_warn(cdev, "Invalid shmem descriptor for '%s'\n",  in mailbox_chan_validate()
92 			ret = -EINVAL;  in mailbox_chan_validate()
106 	struct device *cdev = cinfo->dev;  in mailbox_chan_setup()
108 	struct device_node *shmem;  in mailbox_chan_setup()  local
120 		return -ENOMEM;  in mailbox_chan_setup()
122 	shmem = of_parse_phandle(cdev->of_node, "shmem", idx);  in mailbox_chan_setup()
123 	ret = of_address_to_resource(shmem, 0, &res);  in mailbox_chan_setup()
124 	of_node_put(shmem);  in mailbox_chan_setup()
126 		dev_err(cdev, "failed to get SCMI %s shared memory\n", desc);  in mailbox_chan_setup()
131 	smbox->shmem = devm_ioremap(dev, res.start, size);  in mailbox_chan_setup()
132 	if (!smbox->shmem) {  in mailbox_chan_setup()
133 		dev_err(dev, "failed to ioremap SCMI %s shared memory\n", desc);  in mailbox_chan_setup()
134 		return -EADDRNOTAVAIL;  in mailbox_chan_setup()
137 	cl = &smbox->cl;  in mailbox_chan_setup()
138 	cl->dev = cdev;  in mailbox_chan_setup()
139 	cl->tx_prepare = tx ? tx_prepare : NULL;  in mailbox_chan_setup()
140 	cl->rx_callback = rx_callback;  in mailbox_chan_setup()
141 	cl->tx_block = false;  in mailbox_chan_setup()
142 	cl->knows_txdone = tx;  in mailbox_chan_setup()
144 	smbox->chan = mbox_request_channel(cl, tx ? 0 : 1);  in mailbox_chan_setup()
145 	if (IS_ERR(smbox->chan)) {  in mailbox_chan_setup()
146 		ret = PTR_ERR(smbox->chan);  in mailbox_chan_setup()
147 		if (ret != -EPROBE_DEFER)  in mailbox_chan_setup()
148 			dev_err(cdev, "failed to request SCMI %s mailbox\n",  in mailbox_chan_setup()
153 	cinfo->transport_info = smbox;  in mailbox_chan_setup()
154 	smbox->cinfo = cinfo;  in mailbox_chan_setup()
162 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_chan_free()
164 	if (smbox && !IS_ERR(smbox->chan)) {  in mailbox_chan_free()
165 		mbox_free_channel(smbox->chan);  in mailbox_chan_free()
166 		cinfo->transport_info = NULL;  in mailbox_chan_free()
167 		smbox->chan = NULL;  in mailbox_chan_free()
168 		smbox->cinfo = NULL;  in mailbox_chan_free()
179 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_send_message()
182 	ret = mbox_send_message(smbox->chan, xfer);  in mailbox_send_message()
184 	/* mbox_send_message returns non-negative value on success, so reset */  in mailbox_send_message()
193 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_mark_txdone()
201 	mbox_client_txdone(smbox->chan, ret);  in mailbox_mark_txdone()
207 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_fetch_response()
209 	shmem_fetch_response(smbox->shmem, xfer);  in mailbox_fetch_response()
215 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_fetch_notification()
217 	shmem_fetch_notification(smbox->shmem, max_len, xfer);  in mailbox_fetch_notification()
222 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_clear_channel()
224 	shmem_clear_channel(smbox->shmem);  in mailbox_clear_channel()
230 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_poll_done()
232 	return shmem_poll_done(smbox->shmem, xfer);  in mailbox_poll_done()