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
15 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_create);
16 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_release);
17 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_add);
18 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_del);
19 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_in);
20 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_message_submit);
21
22 static struct ida gb_hd_bus_id_map;
23
gb_hd_output(struct gb_host_device * hd,void * req,u16 size,u8 cmd,bool async)24 int 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 }
31 EXPORT_SYMBOL_GPL(gb_hd_output);
32
bus_id_show(struct device * dev,struct device_attribute * attr,char * buf)33 static 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 }
40 static DEVICE_ATTR_RO(bus_id);
41
42 static struct attribute *bus_attrs[] = {
43 &dev_attr_bus_id.attr,
44 NULL
45 };
46 ATTRIBUTE_GROUPS(bus);
47
gb_hd_cport_reserve(struct gb_host_device * hd,u16 cport_id)48 int 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_simple_get(id_map, cport_id, cport_id + 1, 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 }
61 EXPORT_SYMBOL_GPL(gb_hd_cport_reserve);
62
gb_hd_cport_release_reserved(struct gb_host_device * hd,u16 cport_id)63 void 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_simple_remove(id_map, cport_id);
68 }
69 EXPORT_SYMBOL_GPL(gb_hd_cport_release_reserved);
70
71 /* Locking: Caller guarantees serialisation */
gb_hd_cport_allocate(struct gb_host_device * hd,int cport_id,unsigned long flags)72 int 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;
84 } else if (cport_id < hd->num_cports) {
85 ida_start = cport_id;
86 ida_end = cport_id + 1;
87 } else {
88 dev_err(&hd->dev, "cport %d not available\n", cport_id);
89 return -EINVAL;
90 }
91
92 return ida_simple_get(id_map, ida_start, ida_end, GFP_KERNEL);
93 }
94
95 /* Locking: Caller guarantees serialisation */
gb_hd_cport_release(struct gb_host_device * hd,u16 cport_id)96 void 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_simple_remove(&hd->cport_id_map, cport_id);
104 }
105
gb_hd_release(struct device * dev)106 static 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_simple_remove(&gb_hd_bus_id_map, hd->bus_id);
115 ida_destroy(&hd->cport_id_map);
116 kfree(hd);
117 }
118
119 struct device_type greybus_hd_type = {
120 .name = "greybus_host_device",
121 .release = gb_hd_release,
122 };
123
gb_hd_create(struct gb_hd_driver * driver,struct device * parent,size_t buffer_size_max,size_t num_cports)124 struct 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_simple_get(&gb_hd_bus_id_map, 1, 0, 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 }
198 EXPORT_SYMBOL_GPL(gb_hd_create);
199
gb_hd_add(struct gb_host_device * hd)200 int 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 }
218 EXPORT_SYMBOL_GPL(gb_hd_add);
219
gb_hd_del(struct gb_host_device * hd)220 void 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 }
232 EXPORT_SYMBOL_GPL(gb_hd_del);
233
gb_hd_shutdown(struct gb_host_device * hd)234 void gb_hd_shutdown(struct gb_host_device *hd)
235 {
236 gb_svc_del(hd->svc);
237 }
238 EXPORT_SYMBOL_GPL(gb_hd_shutdown);
239
gb_hd_put(struct gb_host_device * hd)240 void gb_hd_put(struct gb_host_device *hd)
241 {
242 put_device(&hd->dev);
243 }
244 EXPORT_SYMBOL_GPL(gb_hd_put);
245
gb_hd_init(void)246 int __init gb_hd_init(void)
247 {
248 ida_init(&gb_hd_bus_id_map);
249
250 return 0;
251 }
252
gb_hd_exit(void)253 void gb_hd_exit(void)
254 {
255 ida_destroy(&gb_hd_bus_id_map);
256 }
257