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 err = hsi_of_property_parse_mode(client, "hsi-mode", &mode);
228 err = hsi_of_property_parse_mode(client, "hsi-rx-mode",
233 err = hsi_of_property_parse_mode(client, "hsi-tx-mode",
238 cl->rx_cfg.mode = mode;
239 cl->tx_cfg.mode = mode;
242 err = of_property_read_u32(client, "hsi-speed-kbps",
246 cl->rx_cfg.speed = cl->tx_cfg.speed;
248 err = hsi_of_property_parse_flow(client, "hsi-flow",
253 err = hsi_of_property_parse_arb_mode(client, "hsi-arb-mode",
254 &cl->rx_cfg.arb_mode);
258 prop = of_find_property(client, "hsi-channel-ids", &length);
264 cells = length / sizeof(u32);
266 cl->rx_cfg.num_channels = cells;
267 cl->tx_cfg.num_channels = cells;
268 cl->rx_cfg.channels = kcalloc(cells, sizeof(channel), GFP_KERNEL);
269 if (!cl->rx_cfg.channels) {
274 cl->tx_cfg.channels = kcalloc(cells, sizeof(channel), GFP_KERNEL);
275 if (!cl->tx_cfg.channels) {
281 for (i = 0; i < cells; i++) {
282 err = of_property_read_u32_index(client, "hsi-channel-ids", i,
287 err = of_property_read_string_index(client, "hsi-channel-names",
292 if (channel.id > max_chan)
293 max_chan = channel.id;
295 cl->rx_cfg.channels[i] = channel;
296 cl->tx_cfg.channels[i] = channel;
299 cl->rx_cfg.num_hw_channels = max_chan + 1;
300 cl->tx_cfg.num_hw_channels = max_chan + 1;
302 cl->device.bus = &hsi_bus_type;
303 cl->device.parent = &port->device;
304 cl->device.release = hsi_client_release;
305 cl->device.of_node = client;
307 dev_set_name(&cl->device, "%s", name);
308 if (device_register(&cl->device) < 0) {
309 pr_err("hsi: failed to register client: %s\n", name);
310 put_device(&cl->device);
316 kfree(cl->tx_cfg.channels);
318 kfree(cl->rx_cfg.channels);
321 pr_err("hsi client: missing or incorrect of property: err=%d\n", err);
324 void hsi_add_clients_from_dt(struct hsi_port *port, struct device_node *clients)
326 struct device_node *child;
328 /* register hsi-char device */
329 hsi_new_client(port, &hsi_char_dev_info);
331 for_each_available_child_of_node(clients, child)
332 hsi_add_client_from_dt(port, child);
334 EXPORT_SYMBOL_GPL(hsi_add_clients_from_dt);
337 int hsi_remove_client(struct device *dev, void *data __maybe_unused)
339 device_unregister(dev);
343 EXPORT_SYMBOL_GPL(hsi_remove_client);
345 static int hsi_remove_port(struct device *dev, void *data __maybe_unused)
347 device_for_each_child(dev, NULL, hsi_remove_client);
348 device_unregister(dev);
353 static void hsi_controller_release(struct device *dev)
355 struct hsi_controller *hsi = to_hsi_controller(dev);
361 static void hsi_port_release(struct device *dev)
363 kfree(to_hsi_port(dev));
367 * hsi_unregister_port - Unregister an HSI port
368 * @port: The HSI port to unregister
370 void hsi_port_unregister_clients(struct hsi_port *port)
372 device_for_each_child(&port->device, NULL, hsi_remove_client);
374 EXPORT_SYMBOL_GPL(hsi_port_unregister_clients);
377 * hsi_unregister_controller - Unregister an HSI controller
378 * @hsi: The HSI controller to register
380 void hsi_unregister_controller(struct hsi_controller *hsi)
382 device_for_each_child(&hsi->device, NULL, hsi_remove_port);
383 device_unregister(&hsi->device);
385 EXPORT_SYMBOL_GPL(hsi_unregister_controller);
388 * hsi_register_controller - Register an HSI controller and its ports
389 * @hsi: The HSI controller to register
391 * Returns -errno on failure, 0 on success.
393 int hsi_register_controller(struct hsi_controller *hsi)
398 err = device_add(&hsi->device);
401 for (i = 0; i < hsi->num_ports; i++) {
402 hsi->port[i]->device.parent = &hsi->device;
403 err = device_add(&hsi->port[i]->device);
407 /* Populate HSI bus with HSI clients */
408 hsi_scan_board_info(hsi);
413 device_del(&hsi->port[i]->device);
414 device_del(&hsi->device);
418 EXPORT_SYMBOL_GPL(hsi_register_controller);
421 * hsi_register_client_driver - Register an HSI client to the HSI bus
422 * @drv: HSI client driver to register
424 * Returns -errno on failure, 0 on success.
426 int hsi_register_client_driver(struct hsi_client_driver *drv)
428 drv->driver.bus = &hsi_bus_type;
430 return driver_register(&drv->driver);
432 EXPORT_SYMBOL_GPL(hsi_register_client_driver);
434 static inline int hsi_dummy_msg(struct hsi_msg *msg __maybe_unused)
439 static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused)
445 * hsi_put_controller - Free an HSI controller
447 * @hsi: Pointer to the HSI controller to freed
449 * HSI controller drivers should only use this function if they need
450 * to free their allocated hsi_controller structures before a successful
451 * call to hsi_register_controller. Other use is not allowed.
453 void hsi_put_controller(struct hsi_controller *hsi)
460 for (i = 0; i < hsi->num_ports; i++)
461 if (hsi->port && hsi->port[i])
462 put_device(&hsi->port[i]->device);
463 put_device(&hsi->device);
465 EXPORT_SYMBOL_GPL(hsi_put_controller);
468 * hsi_alloc_controller - Allocate an HSI controller and its ports
469 * @n_ports: Number of ports on the HSI controller
470 * @flags: Kernel allocation flags
472 * Return NULL on failure or a pointer to an hsi_controller on success.
474 struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags)
476 struct hsi_controller *hsi;
477 struct hsi_port **port;
483 hsi = kzalloc(sizeof(*hsi), flags);
486 port = kcalloc(n_ports, sizeof(*port), flags);
491 hsi->num_ports = n_ports;
493 hsi->device.release = hsi_controller_release;
494 device_initialize(&hsi->device);
496 for (i = 0; i < n_ports; i++) {
497 port[i] = kzalloc(sizeof(**port), flags);
501 port[i]->async = hsi_dummy_msg;
502 port[i]->setup = hsi_dummy_cl;
503 port[i]->flush = hsi_dummy_cl;
504 port[i]->start_tx = hsi_dummy_cl;
505 port[i]->stop_tx = hsi_dummy_cl;
506 port[i]->release = hsi_dummy_cl;
507 mutex_init(&port[i]->lock);
508 BLOCKING_INIT_NOTIFIER_HEAD(&port[i]->n_head);
509 dev_set_name(&port[i]->device, "port%d", i);
510 hsi->port[i]->device.release = hsi_port_release;
511 device_initialize(&hsi->port[i]->device);
516 hsi_put_controller(hsi);
520 EXPORT_SYMBOL_GPL(hsi_alloc_controller);
523 * hsi_free_msg - Free an HSI message
524 * @msg: Pointer to the HSI message
526 * Client is responsible to free the buffers pointed by the scatterlists.
528 void hsi_free_msg(struct hsi_msg *msg)
532 sg_free_table(&msg->sgt);
535 EXPORT_SYMBOL_GPL(hsi_free_msg);
538 * hsi_alloc_msg - Allocate an HSI message
539 * @nents: Number of memory entries
540 * @flags: Kernel allocation flags
542 * nents can be 0. This mainly makes sense for read transfer.
543 * In that case, HSI drivers will call the complete callback when
544 * there is data to be read without consuming it.
546 * Return NULL on failure or a pointer to an hsi_msg on success.
548 struct hsi_msg *hsi_alloc_msg(unsigned int nents, gfp_t flags)
553 msg = kzalloc(sizeof(*msg), flags);
560 err = sg_alloc_table(&msg->sgt, nents, flags);
568 EXPORT_SYMBOL_GPL(hsi_alloc_msg);
571 * hsi_async - Submit an HSI transfer to the controller
572 * @cl: HSI client sending the transfer
573 * @msg: The HSI transfer passed to controller
575 * The HSI message must have the channel, ttype, complete and destructor
576 * fields set beforehand. If nents > 0 then the client has to initialize
577 * also the scatterlists to point to the buffers to write to or read from.
579 * HSI controllers relay on pre-allocated buffers from their clients and they
580 * do not allocate buffers on their own.
582 * Once the HSI message transfer finishes, the HSI controller calls the
583 * complete callback with the status and actual_len fields of the HSI message
584 * updated. The complete callback can be called before returning from
587 * Returns -errno on failure or 0 on success
589 int hsi_async(struct hsi_client *cl, struct hsi_msg *msg)
591 struct hsi_port *port = hsi_get_port(cl);
593 if (!hsi_port_claimed(cl))
596 WARN_ON_ONCE(!msg->destructor || !msg->complete);
599 return port->async(msg);
601 EXPORT_SYMBOL_GPL(hsi_async);
604 * hsi_claim_port - Claim the HSI client's port
605 * @cl: HSI client that wants to claim its port
606 * @share: Flag to indicate if the client wants to share the port or not.
608 * Returns -errno on failure, 0 on success.
610 int hsi_claim_port(struct hsi_client *cl, unsigned int share)
612 struct hsi_port *port = hsi_get_port(cl);
615 mutex_lock(&port->lock);
616 if ((port->claimed) && (!port->shared || !share)) {
620 if (!try_module_get(to_hsi_controller(port->device.parent)->owner)) {
625 port->shared = !!share;
628 mutex_unlock(&port->lock);
632 EXPORT_SYMBOL_GPL(hsi_claim_port);
635 * hsi_release_port - Release the HSI client's port
636 * @cl: HSI client which previously claimed its port
638 void hsi_release_port(struct hsi_client *cl)
640 struct hsi_port *port = hsi_get_port(cl);
642 mutex_lock(&port->lock);
643 /* Allow HW driver to do some cleanup */
647 BUG_ON(port->claimed < 0);
651 module_put(to_hsi_controller(port->device.parent)->owner);
652 mutex_unlock(&port->lock);
654 EXPORT_SYMBOL_GPL(hsi_release_port);
656 static int hsi_event_notifier_call(struct notifier_block *nb,
657 unsigned long event, void *data __maybe_unused)
659 struct hsi_client *cl = container_of(nb, struct hsi_client, nb);
661 (*cl->ehandler)(cl, event);
667 * hsi_register_port_event - Register a client to receive port events
668 * @cl: HSI client that wants to receive port events
669 * @handler: Event handler callback
671 * Clients should register a callback to be able to receive
672 * events from the ports. Registration should happen after
674 * The handler can be called in interrupt context.
676 * Returns -errno on error, or 0 on success.
678 int hsi_register_port_event(struct hsi_client *cl,
679 void (*handler)(struct hsi_client *, unsigned long))
681 struct hsi_port *port = hsi_get_port(cl);
683 if (!handler || cl->ehandler)
685 if (!hsi_port_claimed(cl))
687 cl->ehandler = handler;
688 cl->nb.notifier_call = hsi_event_notifier_call;
690 return blocking_notifier_chain_register(&port->n_head, &cl->nb);
692 EXPORT_SYMBOL_GPL(hsi_register_port_event);
695 * hsi_unregister_port_event - Stop receiving port events for a client
696 * @cl: HSI client that wants to stop receiving port events
698 * Clients should call this function before releasing their associated
701 * Returns -errno on error, or 0 on success.
703 int hsi_unregister_port_event(struct hsi_client *cl)
705 struct hsi_port *port = hsi_get_port(cl);
708 WARN_ON(!hsi_port_claimed(cl));
710 err = blocking_notifier_chain_unregister(&port->n_head, &cl->nb);
716 EXPORT_SYMBOL_GPL(hsi_unregister_port_event);
719 * hsi_event - Notifies clients about port events
720 * @port: Port where the event occurred
721 * @event: The event type
723 * Clients should not be concerned about wake line behavior. However, due
724 * to a race condition in HSI HW protocol, clients need to be notified
725 * about wake line changes, so they can implement a workaround for it.
728 * HSI_EVENT_START_RX - Incoming wake line high
729 * HSI_EVENT_STOP_RX - Incoming wake line down
731 * Returns -errno on error, or 0 on success.
733 int hsi_event(struct hsi_port *port, unsigned long event)
735 return blocking_notifier_call_chain(&port->n_head, event, NULL);
737 EXPORT_SYMBOL_GPL(hsi_event);
740 * hsi_get_channel_id_by_name - acquire channel id by channel name
741 * @cl: HSI client, which uses the channel
742 * @name: name the channel is known under
744 * Clients can call this function to get the hsi channel ids similar to
745 * requesting IRQs or GPIOs by name. This function assumes the same
746 * channel configuration is used for RX and TX.
748 * Returns -errno on error or channel id on success.
750 int hsi_get_channel_id_by_name(struct hsi_client *cl, char *name)
754 if (!cl->rx_cfg.channels)
757 for (i = 0; i < cl->rx_cfg.num_channels; i++)
758 if (!strcmp(cl->rx_cfg.channels[i].name, name))
759 return cl->rx_cfg.channels[i].id;
763 EXPORT_SYMBOL_GPL(hsi_get_channel_id_by_name);
765 static int __init hsi_init(void)
767 return bus_register(&hsi_bus_type);
769 postcore_initcall(hsi_init);
771 static void __exit hsi_exit(void)
773 bus_unregister(&hsi_bus_type);
775 module_exit(hsi_exit);
777 MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
778 MODULE_DESCRIPTION("High-speed Synchronous Serial Interface (HSI) framework");
779 MODULE_LICENSE("GPL v2");