1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Greybus Host Device
4 *
5 * Copyright 2014-2015 Google Inc.
6 * Copyright 2014-2015 Linaro Ltd.
7 */
8
9#include <linux/kernel.h>
10#include <linux/slab.h>
11#include <linux/greybus.h>
12
13#include "greybus_trace.h"
14
15EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_create);
16EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_release);
17EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_add);
18EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_del);
19EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_in);
20EXPORT_TRACEPOINT_SYMBOL_GPL(gb_message_submit);
21
22static struct ida gb_hd_bus_id_map;
23
24int gb_hd_output(struct gb_host_device *hd, void *req, u16 size, u8 cmd,
25		 bool async)
26{
27	if (!hd || !hd->driver || !hd->driver->output)
28		return -EINVAL;
29	return hd->driver->output(hd, req, size, cmd, async);
30}
31EXPORT_SYMBOL_GPL(gb_hd_output);
32
33static ssize_t bus_id_show(struct device *dev,
34			   struct device_attribute *attr, char *buf)
35{
36	struct gb_host_device *hd = to_gb_host_device(dev);
37
38	return sprintf(buf, "%d\n", hd->bus_id);
39}
40static DEVICE_ATTR_RO(bus_id);
41
42static struct attribute *bus_attrs[] = {
43	&dev_attr_bus_id.attr,
44	NULL
45};
46ATTRIBUTE_GROUPS(bus);
47
48int gb_hd_cport_reserve(struct gb_host_device *hd, u16 cport_id)
49{
50	struct ida *id_map = &hd->cport_id_map;
51	int ret;
52
53	ret = ida_alloc_range(id_map, cport_id, cport_id, GFP_KERNEL);
54	if (ret < 0) {
55		dev_err(&hd->dev, "failed to reserve cport %u\n", cport_id);
56		return ret;
57	}
58
59	return 0;
60}
61EXPORT_SYMBOL_GPL(gb_hd_cport_reserve);
62
63void gb_hd_cport_release_reserved(struct gb_host_device *hd, u16 cport_id)
64{
65	struct ida *id_map = &hd->cport_id_map;
66
67	ida_free(id_map, cport_id);
68}
69EXPORT_SYMBOL_GPL(gb_hd_cport_release_reserved);
70
71/* Locking: Caller guarantees serialisation */
72int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id,
73			 unsigned long flags)
74{
75	struct ida *id_map = &hd->cport_id_map;
76	int ida_start, ida_end;
77
78	if (hd->driver->cport_allocate)
79		return hd->driver->cport_allocate(hd, cport_id, flags);
80
81	if (cport_id < 0) {
82		ida_start = 0;
83		ida_end = hd->num_cports - 1;
84	} else if (cport_id < hd->num_cports) {
85		ida_start = cport_id;
86		ida_end = cport_id;
87	} else {
88		dev_err(&hd->dev, "cport %d not available\n", cport_id);
89		return -EINVAL;
90	}
91
92	return ida_alloc_range(id_map, ida_start, ida_end, GFP_KERNEL);
93}
94
95/* Locking: Caller guarantees serialisation */
96void gb_hd_cport_release(struct gb_host_device *hd, u16 cport_id)
97{
98	if (hd->driver->cport_release) {
99		hd->driver->cport_release(hd, cport_id);
100		return;
101	}
102
103	ida_free(&hd->cport_id_map, cport_id);
104}
105
106static void gb_hd_release(struct device *dev)
107{
108	struct gb_host_device *hd = to_gb_host_device(dev);
109
110	trace_gb_hd_release(hd);
111
112	if (hd->svc)
113		gb_svc_put(hd->svc);
114	ida_free(&gb_hd_bus_id_map, hd->bus_id);
115	ida_destroy(&hd->cport_id_map);
116	kfree(hd);
117}
118
119const struct device_type greybus_hd_type = {
120	.name		= "greybus_host_device",
121	.release	= gb_hd_release,
122};
123
124struct gb_host_device *gb_hd_create(struct gb_hd_driver *driver,
125				    struct device *parent,
126				    size_t buffer_size_max,
127				    size_t num_cports)
128{
129	struct gb_host_device *hd;
130	int ret;
131
132	/*
133	 * Validate that the driver implements all of the callbacks
134	 * so that we don't have to every time we make them.
135	 */
136	if ((!driver->message_send) || (!driver->message_cancel)) {
137		dev_err(parent, "mandatory hd-callbacks missing\n");
138		return ERR_PTR(-EINVAL);
139	}
140
141	if (buffer_size_max < GB_OPERATION_MESSAGE_SIZE_MIN) {
142		dev_err(parent, "greybus host-device buffers too small\n");
143		return ERR_PTR(-EINVAL);
144	}
145
146	if (num_cports == 0 || num_cports > CPORT_ID_MAX + 1) {
147		dev_err(parent, "Invalid number of CPorts: %zu\n", num_cports);
148		return ERR_PTR(-EINVAL);
149	}
150
151	/*
152	 * Make sure to never allocate messages larger than what the Greybus
153	 * protocol supports.
154	 */
155	if (buffer_size_max > GB_OPERATION_MESSAGE_SIZE_MAX) {
156		dev_warn(parent, "limiting buffer size to %u\n",
157			 GB_OPERATION_MESSAGE_SIZE_MAX);
158		buffer_size_max = GB_OPERATION_MESSAGE_SIZE_MAX;
159	}
160
161	hd = kzalloc(sizeof(*hd) + driver->hd_priv_size, GFP_KERNEL);
162	if (!hd)
163		return ERR_PTR(-ENOMEM);
164
165	ret = ida_alloc_min(&gb_hd_bus_id_map, 1, GFP_KERNEL);
166	if (ret < 0) {
167		kfree(hd);
168		return ERR_PTR(ret);
169	}
170	hd->bus_id = ret;
171
172	hd->driver = driver;
173	INIT_LIST_HEAD(&hd->modules);
174	INIT_LIST_HEAD(&hd->connections);
175	ida_init(&hd->cport_id_map);
176	hd->buffer_size_max = buffer_size_max;
177	hd->num_cports = num_cports;
178
179	hd->dev.parent = parent;
180	hd->dev.bus = &greybus_bus_type;
181	hd->dev.type = &greybus_hd_type;
182	hd->dev.groups = bus_groups;
183	hd->dev.dma_mask = hd->dev.parent->dma_mask;
184	device_initialize(&hd->dev);
185	dev_set_name(&hd->dev, "greybus%d", hd->bus_id);
186
187	trace_gb_hd_create(hd);
188
189	hd->svc = gb_svc_create(hd);
190	if (!hd->svc) {
191		dev_err(&hd->dev, "failed to create svc\n");
192		put_device(&hd->dev);
193		return ERR_PTR(-ENOMEM);
194	}
195
196	return hd;
197}
198EXPORT_SYMBOL_GPL(gb_hd_create);
199
200int gb_hd_add(struct gb_host_device *hd)
201{
202	int ret;
203
204	ret = device_add(&hd->dev);
205	if (ret)
206		return ret;
207
208	ret = gb_svc_add(hd->svc);
209	if (ret) {
210		device_del(&hd->dev);
211		return ret;
212	}
213
214	trace_gb_hd_add(hd);
215
216	return 0;
217}
218EXPORT_SYMBOL_GPL(gb_hd_add);
219
220void gb_hd_del(struct gb_host_device *hd)
221{
222	trace_gb_hd_del(hd);
223
224	/*
225	 * Tear down the svc and flush any on-going hotplug processing before
226	 * removing the remaining interfaces.
227	 */
228	gb_svc_del(hd->svc);
229
230	device_del(&hd->dev);
231}
232EXPORT_SYMBOL_GPL(gb_hd_del);
233
234void gb_hd_shutdown(struct gb_host_device *hd)
235{
236	gb_svc_del(hd->svc);
237}
238EXPORT_SYMBOL_GPL(gb_hd_shutdown);
239
240void gb_hd_put(struct gb_host_device *hd)
241{
242	put_device(&hd->dev);
243}
244EXPORT_SYMBOL_GPL(gb_hd_put);
245
246int __init gb_hd_init(void)
247{
248	ida_init(&gb_hd_bus_id_map);
249
250	return 0;
251}
252
253void gb_hd_exit(void)
254{
255	ida_destroy(&gb_hd_bus_id_map);
256}
257