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()
46 	scmi_rx_callback(smbox->cinfo, shmem_read_header(smbox->shmem), NULL);  in rx_callback()
51 	return !of_parse_phandle_with_args(dev->of_node, "mboxes",  in mailbox_chan_available()
52 					   "#mbox-cells", idx, NULL);  in mailbox_chan_available()
59 	struct device *cdev = cinfo->dev;  in mailbox_chan_setup()
61 	struct device_node *shmem;  in mailbox_chan_setup()  local
69 		return -ENOMEM;  in mailbox_chan_setup()
71 	shmem = of_parse_phandle(cdev->of_node, "shmem", idx);  in mailbox_chan_setup()
72 	if (!of_device_is_compatible(shmem, "arm,scmi-shmem"))  in mailbox_chan_setup()
73 		return -ENXIO;  in mailbox_chan_setup()
75 	ret = of_address_to_resource(shmem, 0, &res);  in mailbox_chan_setup()
76 	of_node_put(shmem);  in mailbox_chan_setup()
78 		dev_err(cdev, "failed to get SCMI %s shared memory\n", desc);  in mailbox_chan_setup()
83 	smbox->shmem = devm_ioremap(dev, res.start, size);  in mailbox_chan_setup()
84 	if (!smbox->shmem) {  in mailbox_chan_setup()
85 		dev_err(dev, "failed to ioremap SCMI %s shared memory\n", desc);  in mailbox_chan_setup()
86 		return -EADDRNOTAVAIL;  in mailbox_chan_setup()
89 	cl = &smbox->cl;  in mailbox_chan_setup()
90 	cl->dev = cdev;  in mailbox_chan_setup()
91 	cl->tx_prepare = tx ? tx_prepare : NULL;  in mailbox_chan_setup()
92 	cl->rx_callback = rx_callback;  in mailbox_chan_setup()
93 	cl->tx_block = false;  in mailbox_chan_setup()
94 	cl->knows_txdone = tx;  in mailbox_chan_setup()
96 	smbox->chan = mbox_request_channel(cl, tx ? 0 : 1);  in mailbox_chan_setup()
97 	if (IS_ERR(smbox->chan)) {  in mailbox_chan_setup()
98 		ret = PTR_ERR(smbox->chan);  in mailbox_chan_setup()
99 		if (ret != -EPROBE_DEFER)  in mailbox_chan_setup()
100 			dev_err(cdev, "failed to request SCMI %s mailbox\n",  in mailbox_chan_setup()
105 	cinfo->transport_info = smbox;  in mailbox_chan_setup()
106 	smbox->cinfo = cinfo;  in mailbox_chan_setup()
114 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_chan_free()
116 	if (smbox && !IS_ERR(smbox->chan)) {  in mailbox_chan_free()
117 		mbox_free_channel(smbox->chan);  in mailbox_chan_free()
118 		cinfo->transport_info = NULL;  in mailbox_chan_free()
119 		smbox->chan = NULL;  in mailbox_chan_free()
120 		smbox->cinfo = NULL;  in mailbox_chan_free()
131 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_send_message()
134 	ret = mbox_send_message(smbox->chan, xfer);  in mailbox_send_message()
136 	/* mbox_send_message returns non-negative value on success, so reset */  in mailbox_send_message()
145 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_mark_txdone()
153 	mbox_client_txdone(smbox->chan, ret);  in mailbox_mark_txdone()
159 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_fetch_response()
161 	shmem_fetch_response(smbox->shmem, xfer);  in mailbox_fetch_response()
167 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_fetch_notification()
169 	shmem_fetch_notification(smbox->shmem, max_len, xfer);  in mailbox_fetch_notification()
174 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_clear_channel()
176 	shmem_clear_channel(smbox->shmem);  in mailbox_clear_channel()
182 	struct scmi_mailbox *smbox = cinfo->transport_info;  in mailbox_poll_done()
184 	return shmem_poll_done(smbox->shmem, xfer);  in mailbox_poll_done()