1 // SPDX-License-Identifier: GPL-2.0
4  * "DSP0233 Management Component Transport Protocol (MCTP) I3C Transport
17 #include <net/mctp.h>
24 /* 64 byte payload, 4 byte MCTP header */
27 static const int MCTP_I3C_MAXMTU = MCTP_I3C_MAXBUF - 1;
28 /* 4 byte MCTP header, no data, 1 byte PEC */
42 static const char *MCTP_I3C_OF_PROP = "mctp-controller";
64 	/* Provisioned ID of our controller */
102 	struct i3c_priv_xfer xfer = { .rnw = 1, .len = mi->mrl };  in mctp_i3c_read()
103 	struct net_device_stats *stats = &mi->mbus->ndev->stats;  in mctp_i3c_read()
110 	skb = netdev_alloc_skb(mi->mbus->ndev,  in mctp_i3c_read()
111 			       mi->mrl + sizeof(struct mctp_i3c_internal_hdr));  in mctp_i3c_read()
113 		stats->rx_dropped++;  in mctp_i3c_read()
114 		rc = -ENOMEM;  in mctp_i3c_read()
118 	skb->protocol = htons(ETH_P_MCTP);  in mctp_i3c_read()
122 	put_unaligned_be48(mi->pid, ihdr->source);  in mctp_i3c_read()
123 	put_unaligned_be48(mi->mbus->pid, ihdr->dest);  in mctp_i3c_read()
126 	xfer.data.in = skb_put(skb, mi->mrl);  in mctp_i3c_read()
128 	rc = i3c_device_do_priv_xfers(mi->i3c, &xfer, 1);  in mctp_i3c_read()
132 	if (WARN_ON_ONCE(xfer.len > mi->mrl)) {  in mctp_i3c_read()
134 		rc = -EIO;  in mctp_i3c_read()
138 		stats->rx_length_errors++;  in mctp_i3c_read()
139 		rc = -EIO;  in mctp_i3c_read()
144 	addr = mi->addr << 1 | 1;  in mctp_i3c_read()
146 	pec = i2c_smbus_pec(pec, xfer.data.in, xfer.len - 1);  in mctp_i3c_read()
147 	if (pec != ((u8 *)xfer.data.in)[xfer.len - 1]) {  in mctp_i3c_read()
148 		stats->rx_crc_errors++;  in mctp_i3c_read()
149 		rc = -EINVAL;  in mctp_i3c_read()
154 	skb_trim(skb, xfer.len - 1);  in mctp_i3c_read()
157 	cb->halen = PID_SIZE;  in mctp_i3c_read()
158 	put_unaligned_be48(mi->pid, cb->haddr);  in mctp_i3c_read()
163 		stats->rx_packets++;  in mctp_i3c_read()
164 		stats->rx_bytes += xfer.len - 1;  in mctp_i3c_read()
166 		stats->rx_dropped++;  in mctp_i3c_read()
183 	if (mi->have_mdb) {  in mctp_i3c_ibi_handler()
184 		if (payload->len > 0) {  in mctp_i3c_ibi_handler()
185 			if (((u8 *)payload->data)[0] != I3C_MDB_MCTP) {  in mctp_i3c_ibi_handler()
186 				/* Not a mctp-i3c interrupt, ignore it */  in mctp_i3c_ibi_handler()
210 	i3c_device_get_info(mi->i3c, &info);  in mctp_i3c_setup()
211 	mi->have_mdb = info.bcr & BIT(2);  in mctp_i3c_setup()
212 	mi->addr = info.dyn_addr;  in mctp_i3c_setup()
213 	mi->mwl = info.max_write_len;  in mctp_i3c_setup()
214 	mi->mrl = info.max_read_len;  in mctp_i3c_setup()
215 	mi->pid = info.pid;  in mctp_i3c_setup()
217 	rc = i3c_device_request_ibi(mi->i3c, &ibi);  in mctp_i3c_setup()
218 	if (rc == -ENOTSUPP) {  in mctp_i3c_setup()
219 		/* This driver only supports In-Band Interrupt mode.  in mctp_i3c_setup()
223 		dev_warn(i3cdev_to_dev(mi->i3c),  in mctp_i3c_setup()
224 			 "Failed, bus driver doesn't support In-Band Interrupts");  in mctp_i3c_setup()
227 		dev_err(i3cdev_to_dev(mi->i3c),  in mctp_i3c_setup()
232 	rc = i3c_device_enable_ibi(mi->i3c);  in mctp_i3c_setup()
237 		dev_err(i3cdev_to_dev(mi->i3c), "Failed enabling IBI (%d)\n", rc);  in mctp_i3c_setup()
244 	i3c_device_free_ibi(mi->i3c);  in mctp_i3c_setup()
250 /* Adds a new MCTP i3c_device to a bus */
260 		rc = -ENOMEM;  in mctp_i3c_add_device()
263 	mi->mbus = mbus;  in mctp_i3c_add_device()
264 	mi->i3c = i3c;  in mctp_i3c_add_device()
265 	mutex_init(&mi->lock);  in mctp_i3c_add_device()
266 	list_add(&mi->list, &mbus->devs);  in mctp_i3c_add_device()
276 	list_del(&mi->list);  in mctp_i3c_add_device()
280 	dev_warn(i3cdev_to_dev(i3c), "Error adding mctp-i3c device, %d\n", rc);  in mctp_i3c_add_device()
291 		if (b->bus == i3c->bus) {  in mctp_i3c_probe()
298 		/* probably no "mctp-controller" property on the i3c bus */  in mctp_i3c_probe()
299 		return -ENODEV;  in mctp_i3c_probe()
309 	mutex_lock(&mi->lock);  in mctp_i3c_remove_device()
312 	i3c_device_disable_ibi(mi->i3c);  in mctp_i3c_remove_device()
313 	i3c_device_free_ibi(mi->i3c);  in mctp_i3c_remove_device()
316 	i3cdev_set_drvdata(mi->i3c, NULL);  in mctp_i3c_remove_device()
317 	list_del(&mi->list);  in mctp_i3c_remove_device()
320 	mutex_unlock(&mi->lock);  in mctp_i3c_remove_device()
339 /* Returns the device for an address, with mi->lock held */
346 	list_for_each_entry(mi, &mbus->devs, list)  in mctp_i3c_lookup()
347 		if (mi->pid == pid) {  in mctp_i3c_lookup()
349 			mutex_lock(&mi->lock);  in mctp_i3c_lookup()
358 	struct net_device_stats *stats = &mbus->ndev->stats;  in mctp_i3c_xmit()
369 	data_len = skb->len;  in mctp_i3c_xmit()
373 	pid = get_unaligned_be48(ihdr->dest);  in mctp_i3c_xmit()
377 		stats->tx_dropped++;  in mctp_i3c_xmit()
384 	if (data_len + 1 > (unsigned int)mi->mwl) {  in mctp_i3c_xmit()
386 		stats->tx_dropped++;  in mctp_i3c_xmit()
394 		data = skb->data;  in mctp_i3c_xmit()
397 		skb_copy_bits(skb, 0, mbus->tx_scratch, skb->len);  in mctp_i3c_xmit()
398 		data = mbus->tx_scratch;  in mctp_i3c_xmit()
402 	addr = mi->addr << 1;  in mctp_i3c_xmit()
408 	rc = i3c_device_do_priv_xfers(mi->i3c, &xfer, 1);  in mctp_i3c_xmit()
410 		stats->tx_bytes += data_len;  in mctp_i3c_xmit()
411 		stats->tx_packets++;  in mctp_i3c_xmit()
413 		stats->tx_errors++;  in mctp_i3c_xmit()
418 		mutex_unlock(&mi->lock);  in mctp_i3c_xmit()
430 		spin_lock_bh(&mbus->tx_lock);  in mctp_i3c_tx_thread()
431 		skb = mbus->tx_skb;  in mctp_i3c_tx_thread()
432 		mbus->tx_skb = NULL;  in mctp_i3c_tx_thread()
433 		spin_unlock_bh(&mbus->tx_lock);  in mctp_i3c_tx_thread()
435 		if (netif_queue_stopped(mbus->ndev))  in mctp_i3c_tx_thread()
436 			netif_wake_queue(mbus->ndev);  in mctp_i3c_tx_thread()
442 			wait_event_idle(mbus->tx_wq,  in mctp_i3c_tx_thread()
443 					mbus->tx_skb || kthread_should_stop());  in mctp_i3c_tx_thread()
456 	spin_lock(&mbus->tx_lock);  in mctp_i3c_start_xmit()
458 	if (mbus->tx_skb) {  in mctp_i3c_start_xmit()
459 		dev_warn_ratelimited(&ndev->dev, "TX with queue stopped");  in mctp_i3c_start_xmit()
462 		mbus->tx_skb = skb;  in mctp_i3c_start_xmit()
465 	spin_unlock(&mbus->tx_lock);  in mctp_i3c_start_xmit()
468 		wake_up(&mbus->tx_wq);  in mctp_i3c_start_xmit()
478 	if (mbus->tx_thread) {  in mctp_i3c_bus_free()
479 		kthread_stop(mbus->tx_thread);  in mctp_i3c_bus_free()
480 		mbus->tx_thread = NULL;  in mctp_i3c_bus_free()
484 	list_for_each_entry_safe(mi, tmp, &mbus->devs, list) {  in mctp_i3c_bus_free()
488 	kfree_skb(mbus->tx_skb);  in mctp_i3c_bus_free()
489 	list_del(&mbus->list);  in mctp_i3c_bus_free()
509 	memcpy(ihdr->dest, daddr, PID_SIZE);  in mctp_i3c_header_create()
510 	memcpy(ihdr->source, saddr, PID_SIZE);  in mctp_i3c_header_create()
525 	dev->type = ARPHRD_MCTP;  in mctp_i3c_net_setup()
527 	dev->mtu = MCTP_I3C_MAXMTU;  in mctp_i3c_net_setup()
528 	dev->min_mtu = MCTP_I3C_MINMTU;  in mctp_i3c_net_setup()
529 	dev->max_mtu = MCTP_I3C_MAXMTU;  in mctp_i3c_net_setup()
530 	dev->tx_queue_len = MCTP_I3C_TX_QUEUE_LEN;  in mctp_i3c_net_setup()
532 	dev->hard_header_len = sizeof(struct mctp_i3c_internal_hdr);  in mctp_i3c_net_setup()
533 	dev->addr_len = PID_SIZE;  in mctp_i3c_net_setup()
535 	dev->netdev_ops	= &mctp_i3c_ops;  in mctp_i3c_net_setup()
536 	dev->header_ops	= &mctp_i3c_headops;  in mctp_i3c_net_setup()
541 	struct i3c_dev_desc *master = bus->cur_master;  in mctp_i3c_is_mctp_controller()
546 	return of_property_read_bool(master->common.master->dev.of_node,  in mctp_i3c_is_mctp_controller()
555 	master = bus->cur_master;  in mctp_i3c_bus_local_pid()
557 		return -ENOENT;  in mctp_i3c_bus_local_pid()
558 	*ret_pid = master->info.pid;  in mctp_i3c_bus_local_pid()
574 		return ERR_PTR(-ENOENT);  in mctp_i3c_bus_add()
576 	snprintf(namebuf, sizeof(namebuf), "mctpi3c%d", bus->id);  in mctp_i3c_bus_add()
580 		rc = -ENOMEM;  in mctp_i3c_bus_add()
585 	mbus->ndev = ndev;  in mctp_i3c_bus_add()
586 	mbus->bus = bus;  in mctp_i3c_bus_add()
587 	INIT_LIST_HEAD(&mbus->devs);  in mctp_i3c_bus_add()
588 	list_add(&mbus->list, &busdevs);  in mctp_i3c_bus_add()
590 	rc = mctp_i3c_bus_local_pid(bus, &mbus->pid);  in mctp_i3c_bus_add()
592 		dev_err(&ndev->dev, "No I3C PID available\n");  in mctp_i3c_bus_add()
595 	put_unaligned_be48(mbus->pid, addr);  in mctp_i3c_bus_add()
598 	init_waitqueue_head(&mbus->tx_wq);  in mctp_i3c_bus_add()
599 	spin_lock_init(&mbus->tx_lock);  in mctp_i3c_bus_add()
600 	mbus->tx_thread = kthread_run(mctp_i3c_tx_thread, mbus,  in mctp_i3c_bus_add()
601 				      "%s/tx", ndev->name);  in mctp_i3c_bus_add()
602 	if (IS_ERR(mbus->tx_thread)) {  in mctp_i3c_bus_add()
603 		dev_warn(&ndev->dev, "Error creating thread: %pe\n",  in mctp_i3c_bus_add()
604 			 mbus->tx_thread);  in mctp_i3c_bus_add()
605 		rc = PTR_ERR(mbus->tx_thread);  in mctp_i3c_bus_add()
606 		mbus->tx_thread = NULL;  in mctp_i3c_bus_add()
612 		dev_warn(&ndev->dev, "netdev register failed: %d\n", rc);  in mctp_i3c_bus_add()
633 	/* Unregister calls through to ndo_uninit -> mctp_i3c_bus_free() */  in mctp_i3c_bus_remove()
634 	mctp_unregister_netdev(mbus->ndev);  in mctp_i3c_bus_remove()
636 	free_netdev(mbus->ndev);  in mctp_i3c_bus_remove()
640 /* Removes all mctp-i3c busses */
662 		if (mbus->bus == bus)  in mctp_i3c_bus_add_new()
680 		if (mbus->bus == bus)  in mctp_i3c_notify_bus_remove()
710 		.name = "mctp-i3c",
744 		pr_warn("MCTP I3C could not unregister notifier, %d\n", rc);  in mctp_i3c_mod_exit()
753 MODULE_DESCRIPTION("MCTP I3C device");