1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Greybus Vibrator protocol driver.
4 *
5 * Copyright 2014 Google Inc.
6 * Copyright 2014 Linaro Ltd.
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/device.h>
13 #include <linux/kdev_t.h>
14 #include <linux/idr.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/greybus.h>
17
18 struct gb_vibrator_device {
19 struct gb_connection *connection;
20 struct device *dev;
21 int minor; /* vibrator minor number */
22 struct delayed_work delayed_work;
23 };
24
25 /* Greybus Vibrator operation types */
26 #define GB_VIBRATOR_TYPE_ON 0x02
27 #define GB_VIBRATOR_TYPE_OFF 0x03
28
turn_off(struct gb_vibrator_device * vib)29 static int turn_off(struct gb_vibrator_device *vib)
30 {
31 struct gb_bundle *bundle = vib->connection->bundle;
32 int ret;
33
34 ret = gb_operation_sync(vib->connection, GB_VIBRATOR_TYPE_OFF,
35 NULL, 0, NULL, 0);
36
37 gb_pm_runtime_put_autosuspend(bundle);
38
39 return ret;
40 }
41
turn_on(struct gb_vibrator_device * vib,u16 timeout_ms)42 static int turn_on(struct gb_vibrator_device *vib, u16 timeout_ms)
43 {
44 struct gb_bundle *bundle = vib->connection->bundle;
45 int ret;
46
47 ret = gb_pm_runtime_get_sync(bundle);
48 if (ret)
49 return ret;
50
51 /* Vibrator was switched ON earlier */
52 if (cancel_delayed_work_sync(&vib->delayed_work))
53 turn_off(vib);
54
55 ret = gb_operation_sync(vib->connection, GB_VIBRATOR_TYPE_ON,
56 NULL, 0, NULL, 0);
57 if (ret) {
58 gb_pm_runtime_put_autosuspend(bundle);
59 return ret;
60 }
61
62 schedule_delayed_work(&vib->delayed_work, msecs_to_jiffies(timeout_ms));
63
64 return 0;
65 }
66
gb_vibrator_worker(struct work_struct * work)67 static void gb_vibrator_worker(struct work_struct *work)
68 {
69 struct delayed_work *delayed_work = to_delayed_work(work);
70 struct gb_vibrator_device *vib =
71 container_of(delayed_work,
72 struct gb_vibrator_device,
73 delayed_work);
74
75 turn_off(vib);
76 }
77
timeout_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)78 static ssize_t timeout_store(struct device *dev, struct device_attribute *attr,
79 const char *buf, size_t count)
80 {
81 struct gb_vibrator_device *vib = dev_get_drvdata(dev);
82 unsigned long val;
83 int retval;
84
85 retval = kstrtoul(buf, 10, &val);
86 if (retval < 0) {
87 dev_err(dev, "could not parse timeout value %d\n", retval);
88 return retval;
89 }
90
91 if (val)
92 retval = turn_on(vib, (u16)val);
93 else
94 retval = turn_off(vib);
95 if (retval)
96 return retval;
97
98 return count;
99 }
100 static DEVICE_ATTR_WO(timeout);
101
102 static struct attribute *vibrator_attrs[] = {
103 &dev_attr_timeout.attr,
104 NULL,
105 };
106 ATTRIBUTE_GROUPS(vibrator);
107
108 static struct class vibrator_class = {
109 .name = "vibrator",
110 .owner = THIS_MODULE,
111 .dev_groups = vibrator_groups,
112 };
113
114 static DEFINE_IDA(minors);
115
gb_vibrator_probe(struct gb_bundle * bundle,const struct greybus_bundle_id * id)116 static int gb_vibrator_probe(struct gb_bundle *bundle,
117 const struct greybus_bundle_id *id)
118 {
119 struct greybus_descriptor_cport *cport_desc;
120 struct gb_connection *connection;
121 struct gb_vibrator_device *vib;
122 struct device *dev;
123 int retval;
124
125 if (bundle->num_cports != 1)
126 return -ENODEV;
127
128 cport_desc = &bundle->cport_desc[0];
129 if (cport_desc->protocol_id != GREYBUS_PROTOCOL_VIBRATOR)
130 return -ENODEV;
131
132 vib = kzalloc(sizeof(*vib), GFP_KERNEL);
133 if (!vib)
134 return -ENOMEM;
135
136 connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
137 NULL);
138 if (IS_ERR(connection)) {
139 retval = PTR_ERR(connection);
140 goto err_free_vib;
141 }
142 gb_connection_set_data(connection, vib);
143
144 vib->connection = connection;
145
146 greybus_set_drvdata(bundle, vib);
147
148 retval = gb_connection_enable(connection);
149 if (retval)
150 goto err_connection_destroy;
151
152 /*
153 * For now we create a device in sysfs for the vibrator, but odds are
154 * there is a "real" device somewhere in the kernel for this, but I
155 * can't find it at the moment...
156 */
157 vib->minor = ida_simple_get(&minors, 0, 0, GFP_KERNEL);
158 if (vib->minor < 0) {
159 retval = vib->minor;
160 goto err_connection_disable;
161 }
162 dev = device_create(&vibrator_class, &bundle->dev,
163 MKDEV(0, 0), vib, "vibrator%d", vib->minor);
164 if (IS_ERR(dev)) {
165 retval = -EINVAL;
166 goto err_ida_remove;
167 }
168 vib->dev = dev;
169
170 INIT_DELAYED_WORK(&vib->delayed_work, gb_vibrator_worker);
171
172 gb_pm_runtime_put_autosuspend(bundle);
173
174 return 0;
175
176 err_ida_remove:
177 ida_simple_remove(&minors, vib->minor);
178 err_connection_disable:
179 gb_connection_disable(connection);
180 err_connection_destroy:
181 gb_connection_destroy(connection);
182 err_free_vib:
183 kfree(vib);
184
185 return retval;
186 }
187
gb_vibrator_disconnect(struct gb_bundle * bundle)188 static void gb_vibrator_disconnect(struct gb_bundle *bundle)
189 {
190 struct gb_vibrator_device *vib = greybus_get_drvdata(bundle);
191 int ret;
192
193 ret = gb_pm_runtime_get_sync(bundle);
194 if (ret)
195 gb_pm_runtime_get_noresume(bundle);
196
197 if (cancel_delayed_work_sync(&vib->delayed_work))
198 turn_off(vib);
199
200 device_unregister(vib->dev);
201 ida_simple_remove(&minors, vib->minor);
202 gb_connection_disable(vib->connection);
203 gb_connection_destroy(vib->connection);
204 kfree(vib);
205 }
206
207 static const struct greybus_bundle_id gb_vibrator_id_table[] = {
208 { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_VIBRATOR) },
209 { }
210 };
211 MODULE_DEVICE_TABLE(greybus, gb_vibrator_id_table);
212
213 static struct greybus_driver gb_vibrator_driver = {
214 .name = "vibrator",
215 .probe = gb_vibrator_probe,
216 .disconnect = gb_vibrator_disconnect,
217 .id_table = gb_vibrator_id_table,
218 };
219
gb_vibrator_init(void)220 static __init int gb_vibrator_init(void)
221 {
222 int retval;
223
224 retval = class_register(&vibrator_class);
225 if (retval)
226 return retval;
227
228 retval = greybus_register(&gb_vibrator_driver);
229 if (retval)
230 goto err_class_unregister;
231
232 return 0;
233
234 err_class_unregister:
235 class_unregister(&vibrator_class);
236
237 return retval;
238 }
239 module_init(gb_vibrator_init);
240
gb_vibrator_exit(void)241 static __exit void gb_vibrator_exit(void)
242 {
243 greybus_deregister(&gb_vibrator_driver);
244 class_unregister(&vibrator_class);
245 ida_destroy(&minors);
246 }
247 module_exit(gb_vibrator_exit);
248
249 MODULE_LICENSE("GPL v2");
250