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 .dev_groups = vibrator_groups,
111 };
112
113 static DEFINE_IDA(minors);
114
gb_vibrator_probe(struct gb_bundle * bundle,const struct greybus_bundle_id * id)115 static int gb_vibrator_probe(struct gb_bundle *bundle,
116 const struct greybus_bundle_id *id)
117 {
118 struct greybus_descriptor_cport *cport_desc;
119 struct gb_connection *connection;
120 struct gb_vibrator_device *vib;
121 struct device *dev;
122 int retval;
123
124 if (bundle->num_cports != 1)
125 return -ENODEV;
126
127 cport_desc = &bundle->cport_desc[0];
128 if (cport_desc->protocol_id != GREYBUS_PROTOCOL_VIBRATOR)
129 return -ENODEV;
130
131 vib = kzalloc(sizeof(*vib), GFP_KERNEL);
132 if (!vib)
133 return -ENOMEM;
134
135 connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
136 NULL);
137 if (IS_ERR(connection)) {
138 retval = PTR_ERR(connection);
139 goto err_free_vib;
140 }
141 gb_connection_set_data(connection, vib);
142
143 vib->connection = connection;
144
145 greybus_set_drvdata(bundle, vib);
146
147 retval = gb_connection_enable(connection);
148 if (retval)
149 goto err_connection_destroy;
150
151 /*
152 * For now we create a device in sysfs for the vibrator, but odds are
153 * there is a "real" device somewhere in the kernel for this, but I
154 * can't find it at the moment...
155 */
156 vib->minor = ida_simple_get(&minors, 0, 0, GFP_KERNEL);
157 if (vib->minor < 0) {
158 retval = vib->minor;
159 goto err_connection_disable;
160 }
161 dev = device_create(&vibrator_class, &bundle->dev,
162 MKDEV(0, 0), vib, "vibrator%d", vib->minor);
163 if (IS_ERR(dev)) {
164 retval = -EINVAL;
165 goto err_ida_remove;
166 }
167 vib->dev = dev;
168
169 INIT_DELAYED_WORK(&vib->delayed_work, gb_vibrator_worker);
170
171 gb_pm_runtime_put_autosuspend(bundle);
172
173 return 0;
174
175 err_ida_remove:
176 ida_simple_remove(&minors, vib->minor);
177 err_connection_disable:
178 gb_connection_disable(connection);
179 err_connection_destroy:
180 gb_connection_destroy(connection);
181 err_free_vib:
182 kfree(vib);
183
184 return retval;
185 }
186
gb_vibrator_disconnect(struct gb_bundle * bundle)187 static void gb_vibrator_disconnect(struct gb_bundle *bundle)
188 {
189 struct gb_vibrator_device *vib = greybus_get_drvdata(bundle);
190 int ret;
191
192 ret = gb_pm_runtime_get_sync(bundle);
193 if (ret)
194 gb_pm_runtime_get_noresume(bundle);
195
196 if (cancel_delayed_work_sync(&vib->delayed_work))
197 turn_off(vib);
198
199 device_unregister(vib->dev);
200 ida_simple_remove(&minors, vib->minor);
201 gb_connection_disable(vib->connection);
202 gb_connection_destroy(vib->connection);
203 kfree(vib);
204 }
205
206 static const struct greybus_bundle_id gb_vibrator_id_table[] = {
207 { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_VIBRATOR) },
208 { }
209 };
210 MODULE_DEVICE_TABLE(greybus, gb_vibrator_id_table);
211
212 static struct greybus_driver gb_vibrator_driver = {
213 .name = "vibrator",
214 .probe = gb_vibrator_probe,
215 .disconnect = gb_vibrator_disconnect,
216 .id_table = gb_vibrator_id_table,
217 };
218
gb_vibrator_init(void)219 static __init int gb_vibrator_init(void)
220 {
221 int retval;
222
223 retval = class_register(&vibrator_class);
224 if (retval)
225 return retval;
226
227 retval = greybus_register(&gb_vibrator_driver);
228 if (retval)
229 goto err_class_unregister;
230
231 return 0;
232
233 err_class_unregister:
234 class_unregister(&vibrator_class);
235
236 return retval;
237 }
238 module_init(gb_vibrator_init);
239
gb_vibrator_exit(void)240 static __exit void gb_vibrator_exit(void)
241 {
242 greybus_deregister(&gb_vibrator_driver);
243 class_unregister(&vibrator_class);
244 ida_destroy(&minors);
245 }
246 module_exit(gb_vibrator_exit);
247
248 MODULE_LICENSE("GPL v2");
249