4 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
6 * Contact: Carlos Chinea <carlos.chinea@nokia.com>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * version 2 as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22 #include <linux/hsi/hsi.h>
23 #include <linux/compiler.h>
24 #include <linux/list.h>
25 #include <linux/kobject.h>
26 #include <linux/slab.h>
27 #include <linux/string.h>
28 #include <linux/notifier.h>
30 #include <linux/of_device.h>
33 static ssize_t modalias_show(struct device *dev,
34 struct device_attribute *a __maybe_unused, char *buf)
36 return sprintf(buf, "hsi:%s\n", dev_name(dev));
38 static DEVICE_ATTR_RO(modalias);
40 static struct attribute *hsi_bus_dev_attrs[] = {
41 &dev_attr_modalias.attr,
44 ATTRIBUTE_GROUPS(hsi_bus_dev);
46 static int hsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
48 add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev));
53 static int hsi_bus_match(struct device *dev, struct device_driver *driver)
55 if (of_driver_match_device(dev, driver))
58 if (strcmp(dev_name(dev), driver->name) == 0)
64 static struct bus_type hsi_bus_type = {
66 .dev_groups = hsi_bus_dev_groups,
67 .match = hsi_bus_match,
68 .uevent = hsi_bus_uevent,
71 static void hsi_client_release(struct device *dev)
73 struct hsi_client *cl = to_hsi_client(dev);
75 kfree(cl->tx_cfg.channels);
76 kfree(cl->rx_cfg.channels);
80 struct hsi_client *hsi_new_client(struct hsi_port *port,
81 struct hsi_board_info *info)
83 struct hsi_client *cl;
86 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
90 cl->tx_cfg = info->tx_cfg;
91 if (cl->tx_cfg.channels) {
92 size = cl->tx_cfg.num_channels * sizeof(*cl->tx_cfg.channels);
93 cl->tx_cfg.channels = kmemdup(info->tx_cfg.channels, size,
95 if (!cl->tx_cfg.channels)
99 cl->rx_cfg = info->rx_cfg;
100 if (cl->rx_cfg.channels) {
101 size = cl->rx_cfg.num_channels * sizeof(*cl->rx_cfg.channels);
102 cl->rx_cfg.channels = kmemdup(info->rx_cfg.channels, size,
104 if (!cl->rx_cfg.channels)
108 cl->device.bus = &hsi_bus_type;
109 cl->device.parent = &port->device;
110 cl->device.release = hsi_client_release;
111 dev_set_name(&cl->device, "%s", info->name);
112 cl->device.platform_data = info->platform_data;
114 cl->device.archdata = *info->archdata;
115 if (device_register(&cl->device) < 0) {
116 pr_err("hsi: failed to register client: %s\n", info->name);
117 put_device(&cl->device);
122 kfree(cl->tx_cfg.channels);
128 EXPORT_SYMBOL_GPL(hsi_new_client);
130 static void hsi_scan_board_info(struct hsi_controller *hsi)
132 struct hsi_cl_info *cl_info;
135 list_for_each_entry(cl_info, &hsi_board_list, list)
136 if (cl_info->info.hsi_id == hsi->id) {
137 p = hsi_find_port_num(hsi, cl_info->info.port);
140 hsi_new_client(p, &cl_info->info);
145 static struct hsi_board_info hsi_char_dev_info = {
149 static int hsi_of_property_parse_mode(struct device_node *client, char *name,
150 unsigned int *result)
155 err = of_property_read_string(client, name, &mode);
159 if (strcmp(mode, "stream") == 0)
160 *result = HSI_MODE_STREAM;
161 else if (strcmp(mode, "frame") == 0)
162 *result = HSI_MODE_FRAME;
169 static int hsi_of_property_parse_flow(struct device_node *client, char *name,
170 unsigned int *result)
175 err = of_property_read_string(client, name, &flow);
179 if (strcmp(flow, "synchronized") == 0)
180 *result = HSI_FLOW_SYNC;
181 else if (strcmp(flow, "pipeline") == 0)
182 *result = HSI_FLOW_PIPE;
189 static int hsi_of_property_parse_arb_mode(struct device_node *client,
190 char *name, unsigned int *result)
192 const char *arb_mode;
195 err = of_property_read_string(client, name, &arb_mode);
199 if (strcmp(arb_mode, "round-robin") == 0)
200 *result = HSI_ARB_RR;
201 else if (strcmp(arb_mode, "priority") == 0)
202 *result = HSI_ARB_PRIO;
209 static void hsi_add_client_from_dt(struct hsi_port *port,
210 struct device_node *client)
212 struct hsi_client *cl;
213 struct hsi_channel channel;
214 struct property *prop;
216 int length, cells, err, i, max_chan, mode;
218 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
222 err = of_modalias_node(client, name, sizeof(name));
226 dev_set_name(&cl->device, "%s", name);
228 err = hsi_of_property_parse_mode(client, "hsi-mode", &mode);
230 err = hsi_of_property_parse_mode(client, "hsi-rx-mode",
235 err = hsi_of_property_parse_mode(client, "hsi-tx-mode",
240 cl->rx_cfg.mode = mode;
241 cl->tx_cfg.mode = mode;
244 err = of_property_read_u32(client, "hsi-speed-kbps",
248 cl->rx_cfg.speed = cl->tx_cfg.speed;
250 err = hsi_of_property_parse_flow(client, "hsi-flow",
255 err = hsi_of_property_parse_arb_mode(client, "hsi-arb-mode",
256 &cl->rx_cfg.arb_mode);
260 prop = of_find_property(client, "hsi-channel-ids", &length);
266 cells = length / sizeof(u32);
268 cl->rx_cfg.num_channels = cells;
269 cl->tx_cfg.num_channels = cells;
270 cl->rx_cfg.channels = kcalloc(cells, sizeof(channel), GFP_KERNEL);
271 if (!cl->rx_cfg.channels) {
276 cl->tx_cfg.channels = kcalloc(cells, sizeof(channel), GFP_KERNEL);
277 if (!cl->tx_cfg.channels) {
283 for (i = 0; i < cells; i++) {
284 err = of_property_read_u32_index(client, "hsi-channel-ids", i,
289 err = of_property_read_string_index(client, "hsi-channel-names",
294 if (channel.id > max_chan)
295 max_chan = channel.id;
297 cl->rx_cfg.channels[i] = channel;
298 cl->tx_cfg.channels[i] = channel;
301 cl->rx_cfg.num_hw_channels = max_chan + 1;
302 cl->tx_cfg.num_hw_channels = max_chan + 1;
304 cl->device.bus = &hsi_bus_type;
305 cl->device.parent = &port->device;
306 cl->device.release = hsi_client_release;
307 cl->device.of_node = client;
309 if (device_register(&cl->device) < 0) {
310 pr_err("hsi: failed to register client: %s\n", name);
311 put_device(&cl->device);
317 kfree(cl->tx_cfg.channels);
319 kfree(cl->rx_cfg.channels);
322 pr_err("hsi client: missing or incorrect of property: err=%d\n", err);
325 void hsi_add_clients_from_dt(struct hsi_port *port, struct device_node *clients)
327 struct device_node *child;
329 /* register hsi-char device */
330 hsi_new_client(port, &hsi_char_dev_info);
332 for_each_available_child_of_node(clients, child)
333 hsi_add_client_from_dt(port, child);
335 EXPORT_SYMBOL_GPL(hsi_add_clients_from_dt);
338 int hsi_remove_client(struct device *dev, void *data __maybe_unused)
340 device_unregister(dev);
344 EXPORT_SYMBOL_GPL(hsi_remove_client);
346 static int hsi_remove_port(struct device *dev, void *data __maybe_unused)
348 device_for_each_child(dev, NULL, hsi_remove_client);
349 device_unregister(dev);
354 static void hsi_controller_release(struct device *dev)
356 struct hsi_controller *hsi = to_hsi_controller(dev);
362 static void hsi_port_release(struct device *dev)
364 kfree(to_hsi_port(dev));
368 * hsi_unregister_port - Unregister an HSI port
369 * @port: The HSI port to unregister
371 void hsi_port_unregister_clients(struct hsi_port *port)
373 device_for_each_child(&port->device, NULL, hsi_remove_client);
375 EXPORT_SYMBOL_GPL(hsi_port_unregister_clients);
378 * hsi_unregister_controller - Unregister an HSI controller
379 * @hsi: The HSI controller to register
381 void hsi_unregister_controller(struct hsi_controller *hsi)
383 device_for_each_child(&hsi->device, NULL, hsi_remove_port);
384 device_unregister(&hsi->device);
386 EXPORT_SYMBOL_GPL(hsi_unregister_controller);
389 * hsi_register_controller - Register an HSI controller and its ports
390 * @hsi: The HSI controller to register
392 * Returns -errno on failure, 0 on success.
394 int hsi_register_controller(struct hsi_controller *hsi)
399 err = device_add(&hsi->device);
402 for (i = 0; i < hsi->num_ports; i++) {
403 hsi->port[i]->device.parent = &hsi->device;
404 err = device_add(&hsi->port[i]->device);
408 /* Populate HSI bus with HSI clients */
409 hsi_scan_board_info(hsi);
414 device_del(&hsi->port[i]->device);
415 device_del(&hsi->device);
419 EXPORT_SYMBOL_GPL(hsi_register_controller);
422 * hsi_register_client_driver - Register an HSI client to the HSI bus
423 * @drv: HSI client driver to register
425 * Returns -errno on failure, 0 on success.
427 int hsi_register_client_driver(struct hsi_client_driver *drv)
429 drv->driver.bus = &hsi_bus_type;
431 return driver_register(&drv->driver);
433 EXPORT_SYMBOL_GPL(hsi_register_client_driver);
435 static inline int hsi_dummy_msg(struct hsi_msg *msg __maybe_unused)
440 static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused)
446 * hsi_put_controller - Free an HSI controller
448 * @hsi: Pointer to the HSI controller to freed
450 * HSI controller drivers should only use this function if they need
451 * to free their allocated hsi_controller structures before a successful
452 * call to hsi_register_controller. Other use is not allowed.
454 void hsi_put_controller(struct hsi_controller *hsi)
461 for (i = 0; i < hsi->num_ports; i++)
462 if (hsi->port && hsi->port[i])
463 put_device(&hsi->port[i]->device);
464 put_device(&hsi->device);
466 EXPORT_SYMBOL_GPL(hsi_put_controller);
469 * hsi_alloc_controller - Allocate an HSI controller and its ports
470 * @n_ports: Number of ports on the HSI controller
471 * @flags: Kernel allocation flags
473 * Return NULL on failure or a pointer to an hsi_controller on success.
475 struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags)
477 struct hsi_controller *hsi;
478 struct hsi_port **port;
484 hsi = kzalloc(sizeof(*hsi), flags);
487 port = kcalloc(n_ports, sizeof(*port), flags);
492 hsi->num_ports = n_ports;
494 hsi->device.release = hsi_controller_release;
495 device_initialize(&hsi->device);
497 for (i = 0; i < n_ports; i++) {
498 port[i] = kzalloc(sizeof(**port), flags);
502 port[i]->async = hsi_dummy_msg;
503 port[i]->setup = hsi_dummy_cl;
504 port[i]->flush = hsi_dummy_cl;
505 port[i]->start_tx = hsi_dummy_cl;
506 port[i]->stop_tx = hsi_dummy_cl;
507 port[i]->release = hsi_dummy_cl;
508 mutex_init(&port[i]->lock);
509 BLOCKING_INIT_NOTIFIER_HEAD(&port[i]->n_head);
510 dev_set_name(&port[i]->device, "port%d", i);
511 hsi->port[i]->device.release = hsi_port_release;
512 device_initialize(&hsi->port[i]->device);
517 hsi_put_controller(hsi);
521 EXPORT_SYMBOL_GPL(hsi_alloc_controller);
524 * hsi_free_msg - Free an HSI message
525 * @msg: Pointer to the HSI message
527 * Client is responsible to free the buffers pointed by the scatterlists.
529 void hsi_free_msg(struct hsi_msg *msg)
533 sg_free_table(&msg->sgt);
536 EXPORT_SYMBOL_GPL(hsi_free_msg);
539 * hsi_alloc_msg - Allocate an HSI message
540 * @nents: Number of memory entries
541 * @flags: Kernel allocation flags
543 * nents can be 0. This mainly makes sense for read transfer.
544 * In that case, HSI drivers will call the complete callback when
545 * there is data to be read without consuming it.
547 * Return NULL on failure or a pointer to an hsi_msg on success.
549 struct hsi_msg *hsi_alloc_msg(unsigned int nents, gfp_t flags)
554 msg = kzalloc(sizeof(*msg), flags);
561 err = sg_alloc_table(&msg->sgt, nents, flags);
569 EXPORT_SYMBOL_GPL(hsi_alloc_msg);
572 * hsi_async - Submit an HSI transfer to the controller
573 * @cl: HSI client sending the transfer
574 * @msg: The HSI transfer passed to controller
576 * The HSI message must have the channel, ttype, complete and destructor
577 * fields set beforehand. If nents > 0 then the client has to initialize
578 * also the scatterlists to point to the buffers to write to or read from.
580 * HSI controllers relay on pre-allocated buffers from their clients and they
581 * do not allocate buffers on their own.
583 * Once the HSI message transfer finishes, the HSI controller calls the
584 * complete callback with the status and actual_len fields of the HSI message
585 * updated. The complete callback can be called before returning from
588 * Returns -errno on failure or 0 on success
590 int hsi_async(struct hsi_client *cl, struct hsi_msg *msg)
592 struct hsi_port *port = hsi_get_port(cl);
594 if (!hsi_port_claimed(cl))
597 WARN_ON_ONCE(!msg->destructor || !msg->complete);
600 return port->async(msg);
602 EXPORT_SYMBOL_GPL(hsi_async);
605 * hsi_claim_port - Claim the HSI client's port
606 * @cl: HSI client that wants to claim its port
607 * @share: Flag to indicate if the client wants to share the port or not.
609 * Returns -errno on failure, 0 on success.
611 int hsi_claim_port(struct hsi_client *cl, unsigned int share)
613 struct hsi_port *port = hsi_get_port(cl);
616 mutex_lock(&port->lock);
617 if ((port->claimed) && (!port->shared || !share)) {
621 if (!try_module_get(to_hsi_controller(port->device.parent)->owner)) {
626 port->shared = !!share;
629 mutex_unlock(&port->lock);
633 EXPORT_SYMBOL_GPL(hsi_claim_port);
636 * hsi_release_port - Release the HSI client's port
637 * @cl: HSI client which previously claimed its port
639 void hsi_release_port(struct hsi_client *cl)
641 struct hsi_port *port = hsi_get_port(cl);
643 mutex_lock(&port->lock);
644 /* Allow HW driver to do some cleanup */
648 BUG_ON(port->claimed < 0);
652 module_put(to_hsi_controller(port->device.parent)->owner);
653 mutex_unlock(&port->lock);
655 EXPORT_SYMBOL_GPL(hsi_release_port);
657 static int hsi_event_notifier_call(struct notifier_block *nb,
658 unsigned long event, void *data __maybe_unused)
660 struct hsi_client *cl = container_of(nb, struct hsi_client, nb);
662 (*cl->ehandler)(cl, event);
668 * hsi_register_port_event - Register a client to receive port events
669 * @cl: HSI client that wants to receive port events
670 * @handler: Event handler callback
672 * Clients should register a callback to be able to receive
673 * events from the ports. Registration should happen after
675 * The handler can be called in interrupt context.
677 * Returns -errno on error, or 0 on success.
679 int hsi_register_port_event(struct hsi_client *cl,
680 void (*handler)(struct hsi_client *, unsigned long))
682 struct hsi_port *port = hsi_get_port(cl);
684 if (!handler || cl->ehandler)
686 if (!hsi_port_claimed(cl))
688 cl->ehandler = handler;
689 cl->nb.notifier_call = hsi_event_notifier_call;
691 return blocking_notifier_chain_register(&port->n_head, &cl->nb);
693 EXPORT_SYMBOL_GPL(hsi_register_port_event);
696 * hsi_unregister_port_event - Stop receiving port events for a client
697 * @cl: HSI client that wants to stop receiving port events
699 * Clients should call this function before releasing their associated
702 * Returns -errno on error, or 0 on success.
704 int hsi_unregister_port_event(struct hsi_client *cl)
706 struct hsi_port *port = hsi_get_port(cl);
709 WARN_ON(!hsi_port_claimed(cl));
711 err = blocking_notifier_chain_unregister(&port->n_head, &cl->nb);
717 EXPORT_SYMBOL_GPL(hsi_unregister_port_event);
720 * hsi_event - Notifies clients about port events
721 * @port: Port where the event occurred
722 * @event: The event type
724 * Clients should not be concerned about wake line behavior. However, due
725 * to a race condition in HSI HW protocol, clients need to be notified
726 * about wake line changes, so they can implement a workaround for it.
729 * HSI_EVENT_START_RX - Incoming wake line high
730 * HSI_EVENT_STOP_RX - Incoming wake line down
732 * Returns -errno on error, or 0 on success.
734 int hsi_event(struct hsi_port *port, unsigned long event)
736 return blocking_notifier_call_chain(&port->n_head, event, NULL);
738 EXPORT_SYMBOL_GPL(hsi_event);
741 * hsi_get_channel_id_by_name - acquire channel id by channel name
742 * @cl: HSI client, which uses the channel
743 * @name: name the channel is known under
745 * Clients can call this function to get the hsi channel ids similar to
746 * requesting IRQs or GPIOs by name. This function assumes the same
747 * channel configuration is used for RX and TX.
749 * Returns -errno on error or channel id on success.
751 int hsi_get_channel_id_by_name(struct hsi_client *cl, char *name)
755 if (!cl->rx_cfg.channels)
758 for (i = 0; i < cl->rx_cfg.num_channels; i++)
759 if (!strcmp(cl->rx_cfg.channels[i].name, name))
760 return cl->rx_cfg.channels[i].id;
764 EXPORT_SYMBOL_GPL(hsi_get_channel_id_by_name);
766 static int __init hsi_init(void)
768 return bus_register(&hsi_bus_type);
770 postcore_initcall(hsi_init);
772 static void __exit hsi_exit(void)
774 bus_unregister(&hsi_bus_type);
776 module_exit(hsi_exit);
778 MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
779 MODULE_DESCRIPTION("High-speed Synchronous Serial Interface (HSI) framework");
780 MODULE_LICENSE("GPL v2");