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authorCarlos Chinea <carlos.chinea@nokia.com>2010-04-16 12:01:02 -0400
committerCarlos Chinea <carlos.chinea@nokia.com>2012-01-05 08:42:13 -0500
commita056ab8c7a00a0ffc52e9573bf01257004c2d08c (patch)
treec5ef0df1efcbbe03469257f2cfb4be1fb05809f1 /drivers/hsi
parent805a6af8dba5dfdd35ec35dc52ec0122400b2610 (diff)
HSI: hsi: Introducing HSI framework
Adds HSI framework in to the linux kernel. High Speed Synchronous Serial Interface (HSI) is a serial interface mainly used for connecting application engines (APE) with cellular modem engines (CMT) in cellular handsets. HSI provides multiplexing for up to 16 logical channels, low-latency and full duplex communication. Signed-off-by: Carlos Chinea <carlos.chinea@nokia.com> Acked-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/hsi')
-rw-r--r--drivers/hsi/Kconfig17
-rw-r--r--drivers/hsi/Makefile5
-rw-r--r--drivers/hsi/hsi.c494
-rw-r--r--drivers/hsi/hsi_boardinfo.c62
-rw-r--r--drivers/hsi/hsi_core.h35
5 files changed, 613 insertions, 0 deletions
diff --git a/drivers/hsi/Kconfig b/drivers/hsi/Kconfig
new file mode 100644
index 000000000000..937062e8bcd0
--- /dev/null
+++ b/drivers/hsi/Kconfig
@@ -0,0 +1,17 @@
1#
2# HSI driver configuration
3#
4menuconfig HSI
5 tristate "HSI support"
6 ---help---
7 The "High speed synchronous Serial Interface" is
8 synchronous serial interface used mainly to connect
9 application engines and cellular modems.
10
11if HSI
12
13config HSI_BOARDINFO
14 bool
15 default y
16
17endif # HSI
diff --git a/drivers/hsi/Makefile b/drivers/hsi/Makefile
new file mode 100644
index 000000000000..ed94a3a334a4
--- /dev/null
+++ b/drivers/hsi/Makefile
@@ -0,0 +1,5 @@
1#
2# Makefile for HSI
3#
4obj-$(CONFIG_HSI_BOARDINFO) += hsi_boardinfo.o
5obj-$(CONFIG_HSI) += hsi.o
diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c
new file mode 100644
index 000000000000..4e2d79b79334
--- /dev/null
+++ b/drivers/hsi/hsi.c
@@ -0,0 +1,494 @@
1/*
2 * HSI core.
3 *
4 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
5 *
6 * Contact: Carlos Chinea <carlos.chinea@nokia.com>
7 *
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.
11 *
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.
16 *
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
20 * 02110-1301 USA
21 */
22#include <linux/hsi/hsi.h>
23#include <linux/compiler.h>
24#include <linux/rwsem.h>
25#include <linux/list.h>
26#include <linux/spinlock.h>
27#include <linux/kobject.h>
28#include <linux/slab.h>
29#include <linux/string.h>
30#include "hsi_core.h"
31
32static struct device_type hsi_ctrl = {
33 .name = "hsi_controller",
34};
35
36static struct device_type hsi_cl = {
37 .name = "hsi_client",
38};
39
40static struct device_type hsi_port = {
41 .name = "hsi_port",
42};
43
44static ssize_t modalias_show(struct device *dev,
45 struct device_attribute *a __maybe_unused, char *buf)
46{
47 return sprintf(buf, "hsi:%s\n", dev_name(dev));
48}
49
50static struct device_attribute hsi_bus_dev_attrs[] = {
51 __ATTR_RO(modalias),
52 __ATTR_NULL,
53};
54
55static int hsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
56{
57 if (dev->type == &hsi_cl)
58 add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev));
59
60 return 0;
61}
62
63static int hsi_bus_match(struct device *dev, struct device_driver *driver)
64{
65 return strcmp(dev_name(dev), driver->name) == 0;
66}
67
68static struct bus_type hsi_bus_type = {
69 .name = "hsi",
70 .dev_attrs = hsi_bus_dev_attrs,
71 .match = hsi_bus_match,
72 .uevent = hsi_bus_uevent,
73};
74
75static void hsi_client_release(struct device *dev)
76{
77 kfree(to_hsi_client(dev));
78}
79
80static void hsi_new_client(struct hsi_port *port, struct hsi_board_info *info)
81{
82 struct hsi_client *cl;
83 unsigned long flags;
84
85 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
86 if (!cl)
87 return;
88 cl->device.type = &hsi_cl;
89 cl->tx_cfg = info->tx_cfg;
90 cl->rx_cfg = info->rx_cfg;
91 cl->device.bus = &hsi_bus_type;
92 cl->device.parent = &port->device;
93 cl->device.release = hsi_client_release;
94 dev_set_name(&cl->device, info->name);
95 cl->device.platform_data = info->platform_data;
96 spin_lock_irqsave(&port->clock, flags);
97 list_add_tail(&cl->link, &port->clients);
98 spin_unlock_irqrestore(&port->clock, flags);
99 if (info->archdata)
100 cl->device.archdata = *info->archdata;
101 if (device_register(&cl->device) < 0) {
102 pr_err("hsi: failed to register client: %s\n", info->name);
103 kfree(cl);
104 }
105}
106
107static void hsi_scan_board_info(struct hsi_controller *hsi)
108{
109 struct hsi_cl_info *cl_info;
110 struct hsi_port *p;
111
112 list_for_each_entry(cl_info, &hsi_board_list, list)
113 if (cl_info->info.hsi_id == hsi->id) {
114 p = hsi_find_port_num(hsi, cl_info->info.port);
115 if (!p)
116 continue;
117 hsi_new_client(p, &cl_info->info);
118 }
119}
120
121static int hsi_remove_client(struct device *dev, void *data __maybe_unused)
122{
123 struct hsi_client *cl = to_hsi_client(dev);
124 struct hsi_port *port = to_hsi_port(dev->parent);
125 unsigned long flags;
126
127 spin_lock_irqsave(&port->clock, flags);
128 list_del(&cl->link);
129 spin_unlock_irqrestore(&port->clock, flags);
130 device_unregister(dev);
131
132 return 0;
133}
134
135static int hsi_remove_port(struct device *dev, void *data __maybe_unused)
136{
137 device_for_each_child(dev, NULL, hsi_remove_client);
138 device_unregister(dev);
139
140 return 0;
141}
142
143static void hsi_controller_release(struct device *dev __maybe_unused)
144{
145}
146
147static void hsi_port_release(struct device *dev __maybe_unused)
148{
149}
150
151/**
152 * hsi_unregister_controller - Unregister an HSI controller
153 * @hsi: The HSI controller to register
154 */
155void hsi_unregister_controller(struct hsi_controller *hsi)
156{
157 device_for_each_child(&hsi->device, NULL, hsi_remove_port);
158 device_unregister(&hsi->device);
159}
160EXPORT_SYMBOL_GPL(hsi_unregister_controller);
161
162/**
163 * hsi_register_controller - Register an HSI controller and its ports
164 * @hsi: The HSI controller to register
165 *
166 * Returns -errno on failure, 0 on success.
167 */
168int hsi_register_controller(struct hsi_controller *hsi)
169{
170 unsigned int i;
171 int err;
172
173 hsi->device.type = &hsi_ctrl;
174 hsi->device.bus = &hsi_bus_type;
175 hsi->device.release = hsi_controller_release;
176 err = device_register(&hsi->device);
177 if (err < 0)
178 return err;
179 for (i = 0; i < hsi->num_ports; i++) {
180 hsi->port[i].device.parent = &hsi->device;
181 hsi->port[i].device.bus = &hsi_bus_type;
182 hsi->port[i].device.release = hsi_port_release;
183 hsi->port[i].device.type = &hsi_port;
184 INIT_LIST_HEAD(&hsi->port[i].clients);
185 spin_lock_init(&hsi->port[i].clock);
186 err = device_register(&hsi->port[i].device);
187 if (err < 0)
188 goto out;
189 }
190 /* Populate HSI bus with HSI clients */
191 hsi_scan_board_info(hsi);
192
193 return 0;
194out:
195 hsi_unregister_controller(hsi);
196
197 return err;
198}
199EXPORT_SYMBOL_GPL(hsi_register_controller);
200
201/**
202 * hsi_register_client_driver - Register an HSI client to the HSI bus
203 * @drv: HSI client driver to register
204 *
205 * Returns -errno on failure, 0 on success.
206 */
207int hsi_register_client_driver(struct hsi_client_driver *drv)
208{
209 drv->driver.bus = &hsi_bus_type;
210
211 return driver_register(&drv->driver);
212}
213EXPORT_SYMBOL_GPL(hsi_register_client_driver);
214
215static inline int hsi_dummy_msg(struct hsi_msg *msg __maybe_unused)
216{
217 return 0;
218}
219
220static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused)
221{
222 return 0;
223}
224
225/**
226 * hsi_alloc_controller - Allocate an HSI controller and its ports
227 * @n_ports: Number of ports on the HSI controller
228 * @flags: Kernel allocation flags
229 *
230 * Return NULL on failure or a pointer to an hsi_controller on success.
231 */
232struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags)
233{
234 struct hsi_controller *hsi;
235 struct hsi_port *port;
236 unsigned int i;
237
238 if (!n_ports)
239 return NULL;
240
241 port = kzalloc(sizeof(*port)*n_ports, flags);
242 if (!port)
243 return NULL;
244 hsi = kzalloc(sizeof(*hsi), flags);
245 if (!hsi)
246 goto out;
247 for (i = 0; i < n_ports; i++) {
248 dev_set_name(&port[i].device, "port%d", i);
249 port[i].num = i;
250 port[i].async = hsi_dummy_msg;
251 port[i].setup = hsi_dummy_cl;
252 port[i].flush = hsi_dummy_cl;
253 port[i].start_tx = hsi_dummy_cl;
254 port[i].stop_tx = hsi_dummy_cl;
255 port[i].release = hsi_dummy_cl;
256 mutex_init(&port[i].lock);
257 }
258 hsi->num_ports = n_ports;
259 hsi->port = port;
260
261 return hsi;
262out:
263 kfree(port);
264
265 return NULL;
266}
267EXPORT_SYMBOL_GPL(hsi_alloc_controller);
268
269/**
270 * hsi_free_controller - Free an HSI controller
271 * @hsi: Pointer to HSI controller
272 */
273void hsi_free_controller(struct hsi_controller *hsi)
274{
275 if (!hsi)
276 return;
277
278 kfree(hsi->port);
279 kfree(hsi);
280}
281EXPORT_SYMBOL_GPL(hsi_free_controller);
282
283/**
284 * hsi_free_msg - Free an HSI message
285 * @msg: Pointer to the HSI message
286 *
287 * Client is responsible to free the buffers pointed by the scatterlists.
288 */
289void hsi_free_msg(struct hsi_msg *msg)
290{
291 if (!msg)
292 return;
293 sg_free_table(&msg->sgt);
294 kfree(msg);
295}
296EXPORT_SYMBOL_GPL(hsi_free_msg);
297
298/**
299 * hsi_alloc_msg - Allocate an HSI message
300 * @nents: Number of memory entries
301 * @flags: Kernel allocation flags
302 *
303 * nents can be 0. This mainly makes sense for read transfer.
304 * In that case, HSI drivers will call the complete callback when
305 * there is data to be read without consuming it.
306 *
307 * Return NULL on failure or a pointer to an hsi_msg on success.
308 */
309struct hsi_msg *hsi_alloc_msg(unsigned int nents, gfp_t flags)
310{
311 struct hsi_msg *msg;
312 int err;
313
314 msg = kzalloc(sizeof(*msg), flags);
315 if (!msg)
316 return NULL;
317
318 if (!nents)
319 return msg;
320
321 err = sg_alloc_table(&msg->sgt, nents, flags);
322 if (unlikely(err)) {
323 kfree(msg);
324 msg = NULL;
325 }
326
327 return msg;
328}
329EXPORT_SYMBOL_GPL(hsi_alloc_msg);
330
331/**
332 * hsi_async - Submit an HSI transfer to the controller
333 * @cl: HSI client sending the transfer
334 * @msg: The HSI transfer passed to controller
335 *
336 * The HSI message must have the channel, ttype, complete and destructor
337 * fields set beforehand. If nents > 0 then the client has to initialize
338 * also the scatterlists to point to the buffers to write to or read from.
339 *
340 * HSI controllers relay on pre-allocated buffers from their clients and they
341 * do not allocate buffers on their own.
342 *
343 * Once the HSI message transfer finishes, the HSI controller calls the
344 * complete callback with the status and actual_len fields of the HSI message
345 * updated. The complete callback can be called before returning from
346 * hsi_async.
347 *
348 * Returns -errno on failure or 0 on success
349 */
350int hsi_async(struct hsi_client *cl, struct hsi_msg *msg)
351{
352 struct hsi_port *port = hsi_get_port(cl);
353
354 if (!hsi_port_claimed(cl))
355 return -EACCES;
356
357 WARN_ON_ONCE(!msg->destructor || !msg->complete);
358 msg->cl = cl;
359
360 return port->async(msg);
361}
362EXPORT_SYMBOL_GPL(hsi_async);
363
364/**
365 * hsi_claim_port - Claim the HSI client's port
366 * @cl: HSI client that wants to claim its port
367 * @share: Flag to indicate if the client wants to share the port or not.
368 *
369 * Returns -errno on failure, 0 on success.
370 */
371int hsi_claim_port(struct hsi_client *cl, unsigned int share)
372{
373 struct hsi_port *port = hsi_get_port(cl);
374 int err = 0;
375
376 mutex_lock(&port->lock);
377 if ((port->claimed) && (!port->shared || !share)) {
378 err = -EBUSY;
379 goto out;
380 }
381 if (!try_module_get(to_hsi_controller(port->device.parent)->owner)) {
382 err = -ENODEV;
383 goto out;
384 }
385 port->claimed++;
386 port->shared = !!share;
387 cl->pclaimed = 1;
388out:
389 mutex_unlock(&port->lock);
390
391 return err;
392}
393EXPORT_SYMBOL_GPL(hsi_claim_port);
394
395/**
396 * hsi_release_port - Release the HSI client's port
397 * @cl: HSI client which previously claimed its port
398 */
399void hsi_release_port(struct hsi_client *cl)
400{
401 struct hsi_port *port = hsi_get_port(cl);
402
403 mutex_lock(&port->lock);
404 /* Allow HW driver to do some cleanup */
405 port->release(cl);
406 if (cl->pclaimed)
407 port->claimed--;
408 BUG_ON(port->claimed < 0);
409 cl->pclaimed = 0;
410 if (!port->claimed)
411 port->shared = 0;
412 module_put(to_hsi_controller(port->device.parent)->owner);
413 mutex_unlock(&port->lock);
414}
415EXPORT_SYMBOL_GPL(hsi_release_port);
416
417static int hsi_start_rx(struct hsi_client *cl, void *data __maybe_unused)
418{
419 if (cl->hsi_start_rx)
420 (*cl->hsi_start_rx)(cl);
421
422 return 0;
423}
424
425static int hsi_stop_rx(struct hsi_client *cl, void *data __maybe_unused)
426{
427 if (cl->hsi_stop_rx)
428 (*cl->hsi_stop_rx)(cl);
429
430 return 0;
431}
432
433static int hsi_port_for_each_client(struct hsi_port *port, void *data,
434 int (*fn)(struct hsi_client *cl, void *data))
435{
436 struct hsi_client *cl;
437
438 spin_lock(&port->clock);
439 list_for_each_entry(cl, &port->clients, link) {
440 spin_unlock(&port->clock);
441 (*fn)(cl, data);
442 spin_lock(&port->clock);
443 }
444 spin_unlock(&port->clock);
445
446 return 0;
447}
448
449/**
450 * hsi_event -Notifies clients about port events
451 * @port: Port where the event occurred
452 * @event: The event type
453 *
454 * Clients should not be concerned about wake line behavior. However, due
455 * to a race condition in HSI HW protocol, clients need to be notified
456 * about wake line changes, so they can implement a workaround for it.
457 *
458 * Events:
459 * HSI_EVENT_START_RX - Incoming wake line high
460 * HSI_EVENT_STOP_RX - Incoming wake line down
461 */
462void hsi_event(struct hsi_port *port, unsigned int event)
463{
464 int (*fn)(struct hsi_client *cl, void *data);
465
466 switch (event) {
467 case HSI_EVENT_START_RX:
468 fn = hsi_start_rx;
469 break;
470 case HSI_EVENT_STOP_RX:
471 fn = hsi_stop_rx;
472 break;
473 default:
474 return;
475 }
476 hsi_port_for_each_client(port, NULL, fn);
477}
478EXPORT_SYMBOL_GPL(hsi_event);
479
480static int __init hsi_init(void)
481{
482 return bus_register(&hsi_bus_type);
483}
484postcore_initcall(hsi_init);
485
486static void __exit hsi_exit(void)
487{
488 bus_unregister(&hsi_bus_type);
489}
490module_exit(hsi_exit);
491
492MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
493MODULE_DESCRIPTION("High-speed Synchronous Serial Interface (HSI) framework");
494MODULE_LICENSE("GPL v2");
diff --git a/drivers/hsi/hsi_boardinfo.c b/drivers/hsi/hsi_boardinfo.c
new file mode 100644
index 000000000000..e56bc6da5f98
--- /dev/null
+++ b/drivers/hsi/hsi_boardinfo.c
@@ -0,0 +1,62 @@
1/*
2 * HSI clients registration interface
3 *
4 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
5 *
6 * Contact: Carlos Chinea <carlos.chinea@nokia.com>
7 *
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.
11 *
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.
16 *
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
20 * 02110-1301 USA
21 */
22#include <linux/hsi/hsi.h>
23#include <linux/list.h>
24#include <linux/slab.h>
25#include "hsi_core.h"
26
27/*
28 * hsi_board_list is only used internally by the HSI framework.
29 * No one else is allowed to make use of it.
30 */
31LIST_HEAD(hsi_board_list);
32EXPORT_SYMBOL_GPL(hsi_board_list);
33
34/**
35 * hsi_register_board_info - Register HSI clients information
36 * @info: Array of HSI clients on the board
37 * @len: Length of the array
38 *
39 * HSI clients are statically declared and registered on board files.
40 *
41 * HSI clients will be automatically registered to the HSI bus once the
42 * controller and the port where the clients wishes to attach are registered
43 * to it.
44 *
45 * Return -errno on failure, 0 on success.
46 */
47int __init hsi_register_board_info(struct hsi_board_info const *info,
48 unsigned int len)
49{
50 struct hsi_cl_info *cl_info;
51
52 cl_info = kzalloc(sizeof(*cl_info) * len, GFP_KERNEL);
53 if (!cl_info)
54 return -ENOMEM;
55
56 for (; len; len--, info++, cl_info++) {
57 cl_info->info = *info;
58 list_add_tail(&cl_info->list, &hsi_board_list);
59 }
60
61 return 0;
62}
diff --git a/drivers/hsi/hsi_core.h b/drivers/hsi/hsi_core.h
new file mode 100644
index 000000000000..ab5c2fb175fd
--- /dev/null
+++ b/drivers/hsi/hsi_core.h
@@ -0,0 +1,35 @@
1/*
2 * HSI framework internal interfaces,
3 *
4 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
5 *
6 * Contact: Carlos Chinea <carlos.chinea@nokia.com>
7 *
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.
11 *
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.
16 *
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
20 * 02110-1301 USA
21 */
22
23#ifndef __LINUX_HSI_CORE_H__
24#define __LINUX_HSI_CORE_H__
25
26#include <linux/hsi/hsi.h>
27
28struct hsi_cl_info {
29 struct list_head list;
30 struct hsi_board_info info;
31};
32
33extern struct list_head hsi_board_list;
34
35#endif /* __LINUX_HSI_CORE_H__ */