xref: /openbmc/linux/drivers/i3c/device.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 Cadence Design Systems Inc.
4  *
5  * Author: Boris Brezillon <boris.brezillon@bootlin.com>
6  */
7 
8 #include <linux/atomic.h>
9 #include <linux/bug.h>
10 #include <linux/completion.h>
11 #include <linux/device.h>
12 #include <linux/mutex.h>
13 #include <linux/slab.h>
14 
15 #include "internals.h"
16 
17 /**
18  * i3c_device_do_priv_xfers() - do I3C SDR private transfers directed to a
19  *				specific device
20  *
21  * @dev: device with which the transfers should be done
22  * @xfers: array of transfers
23  * @nxfers: number of transfers
24  *
25  * Initiate one or several private SDR transfers with @dev.
26  *
27  * This function can sleep and thus cannot be called in atomic context.
28  *
29  * Return: 0 in case of success, a negative error core otherwise.
30  */
31 int i3c_device_do_priv_xfers(struct i3c_device *dev,
32 			     struct i3c_priv_xfer *xfers,
33 			     int nxfers)
34 {
35 	int ret, i;
36 
37 	if (nxfers < 1)
38 		return 0;
39 
40 	for (i = 0; i < nxfers; i++) {
41 		if (!xfers[i].len || !xfers[i].data.in)
42 			return -EINVAL;
43 	}
44 
45 	i3c_bus_normaluse_lock(dev->bus);
46 	ret = i3c_dev_do_priv_xfers_locked(dev->desc, xfers, nxfers);
47 	i3c_bus_normaluse_unlock(dev->bus);
48 
49 	return ret;
50 }
51 EXPORT_SYMBOL_GPL(i3c_device_do_priv_xfers);
52 
53 /**
54  * i3c_device_get_info() - get I3C device information
55  *
56  * @dev: device we want information on
57  * @info: the information object to fill in
58  *
59  * Retrieve I3C dev info.
60  */
61 void i3c_device_get_info(struct i3c_device *dev,
62 			 struct i3c_device_info *info)
63 {
64 	if (!info)
65 		return;
66 
67 	i3c_bus_normaluse_lock(dev->bus);
68 	if (dev->desc)
69 		*info = dev->desc->info;
70 	i3c_bus_normaluse_unlock(dev->bus);
71 }
72 EXPORT_SYMBOL_GPL(i3c_device_get_info);
73 
74 /**
75  * i3c_device_disable_ibi() - Disable IBIs coming from a specific device
76  * @dev: device on which IBIs should be disabled
77  *
78  * This function disable IBIs coming from a specific device and wait for
79  * all pending IBIs to be processed.
80  *
81  * Return: 0 in case of success, a negative error core otherwise.
82  */
83 int i3c_device_disable_ibi(struct i3c_device *dev)
84 {
85 	int ret = -ENOENT;
86 
87 	i3c_bus_normaluse_lock(dev->bus);
88 	if (dev->desc) {
89 		mutex_lock(&dev->desc->ibi_lock);
90 		ret = i3c_dev_disable_ibi_locked(dev->desc);
91 		mutex_unlock(&dev->desc->ibi_lock);
92 	}
93 	i3c_bus_normaluse_unlock(dev->bus);
94 
95 	return ret;
96 }
97 EXPORT_SYMBOL_GPL(i3c_device_disable_ibi);
98 
99 /**
100  * i3c_device_enable_ibi() - Enable IBIs coming from a specific device
101  * @dev: device on which IBIs should be enabled
102  *
103  * This function enable IBIs coming from a specific device and wait for
104  * all pending IBIs to be processed. This should be called on a device
105  * where i3c_device_request_ibi() has succeeded.
106  *
107  * Note that IBIs from this device might be received before this function
108  * returns to its caller.
109  *
110  * Return: 0 in case of success, a negative error core otherwise.
111  */
112 int i3c_device_enable_ibi(struct i3c_device *dev)
113 {
114 	int ret = -ENOENT;
115 
116 	i3c_bus_normaluse_lock(dev->bus);
117 	if (dev->desc) {
118 		mutex_lock(&dev->desc->ibi_lock);
119 		ret = i3c_dev_enable_ibi_locked(dev->desc);
120 		mutex_unlock(&dev->desc->ibi_lock);
121 	}
122 	i3c_bus_normaluse_unlock(dev->bus);
123 
124 	return ret;
125 }
126 EXPORT_SYMBOL_GPL(i3c_device_enable_ibi);
127 
128 /**
129  * i3c_device_request_ibi() - Request an IBI
130  * @dev: device for which we should enable IBIs
131  * @req: setup requested for this IBI
132  *
133  * This function is responsible for pre-allocating all resources needed to
134  * process IBIs coming from @dev. When this function returns, the IBI is not
135  * enabled until i3c_device_enable_ibi() is called.
136  *
137  * Return: 0 in case of success, a negative error core otherwise.
138  */
139 int i3c_device_request_ibi(struct i3c_device *dev,
140 			   const struct i3c_ibi_setup *req)
141 {
142 	int ret = -ENOENT;
143 
144 	if (!req->handler || !req->num_slots)
145 		return -EINVAL;
146 
147 	i3c_bus_normaluse_lock(dev->bus);
148 	if (dev->desc) {
149 		mutex_lock(&dev->desc->ibi_lock);
150 		ret = i3c_dev_request_ibi_locked(dev->desc, req);
151 		mutex_unlock(&dev->desc->ibi_lock);
152 	}
153 	i3c_bus_normaluse_unlock(dev->bus);
154 
155 	return ret;
156 }
157 EXPORT_SYMBOL_GPL(i3c_device_request_ibi);
158 
159 /**
160  * i3c_device_free_ibi() - Free all resources needed for IBI handling
161  * @dev: device on which you want to release IBI resources
162  *
163  * This function is responsible for de-allocating resources previously
164  * allocated by i3c_device_request_ibi(). It should be called after disabling
165  * IBIs with i3c_device_disable_ibi().
166  */
167 void i3c_device_free_ibi(struct i3c_device *dev)
168 {
169 	i3c_bus_normaluse_lock(dev->bus);
170 	if (dev->desc) {
171 		mutex_lock(&dev->desc->ibi_lock);
172 		i3c_dev_free_ibi_locked(dev->desc);
173 		mutex_unlock(&dev->desc->ibi_lock);
174 	}
175 	i3c_bus_normaluse_unlock(dev->bus);
176 }
177 EXPORT_SYMBOL_GPL(i3c_device_free_ibi);
178 
179 /**
180  * i3cdev_to_dev() - Returns the device embedded in @i3cdev
181  * @i3cdev: I3C device
182  *
183  * Return: a pointer to a device object.
184  */
185 struct device *i3cdev_to_dev(struct i3c_device *i3cdev)
186 {
187 	return &i3cdev->dev;
188 }
189 EXPORT_SYMBOL_GPL(i3cdev_to_dev);
190 
191 /**
192  * dev_to_i3cdev() - Returns the I3C device containing @dev
193  * @dev: device object
194  *
195  * Return: a pointer to an I3C device object.
196  */
197 struct i3c_device *dev_to_i3cdev(struct device *dev)
198 {
199 	return container_of(dev, struct i3c_device, dev);
200 }
201 EXPORT_SYMBOL_GPL(dev_to_i3cdev);
202 
203 /**
204  * i3c_device_match_id() - Returns the i3c_device_id entry matching @i3cdev
205  * @i3cdev: I3C device
206  * @id_table: I3C device match table
207  *
208  * Return: a pointer to an i3c_device_id object or NULL if there's no match.
209  */
210 const struct i3c_device_id *
211 i3c_device_match_id(struct i3c_device *i3cdev,
212 		    const struct i3c_device_id *id_table)
213 {
214 	struct i3c_device_info devinfo;
215 	const struct i3c_device_id *id;
216 	u16 manuf, part, ext_info;
217 	bool rndpid;
218 
219 	i3c_device_get_info(i3cdev, &devinfo);
220 
221 	manuf = I3C_PID_MANUF_ID(devinfo.pid);
222 	part = I3C_PID_PART_ID(devinfo.pid);
223 	ext_info = I3C_PID_EXTRA_INFO(devinfo.pid);
224 	rndpid = I3C_PID_RND_LOWER_32BITS(devinfo.pid);
225 
226 	for (id = id_table; id->match_flags != 0; id++) {
227 		if ((id->match_flags & I3C_MATCH_DCR) &&
228 		    id->dcr != devinfo.dcr)
229 			continue;
230 
231 		if ((id->match_flags & I3C_MATCH_MANUF) &&
232 		    id->manuf_id != manuf)
233 			continue;
234 
235 		if ((id->match_flags & I3C_MATCH_PART) &&
236 		    (rndpid || id->part_id != part))
237 			continue;
238 
239 		if ((id->match_flags & I3C_MATCH_EXTRA_INFO) &&
240 		    (rndpid || id->extra_info != ext_info))
241 			continue;
242 
243 		return id;
244 	}
245 
246 	return NULL;
247 }
248 EXPORT_SYMBOL_GPL(i3c_device_match_id);
249 
250 /**
251  * i3c_driver_register_with_owner() - register an I3C device driver
252  *
253  * @drv: driver to register
254  * @owner: module that owns this driver
255  *
256  * Register @drv to the core.
257  *
258  * Return: 0 in case of success, a negative error core otherwise.
259  */
260 int i3c_driver_register_with_owner(struct i3c_driver *drv, struct module *owner)
261 {
262 	drv->driver.owner = owner;
263 	drv->driver.bus = &i3c_bus_type;
264 
265 	if (!drv->probe) {
266 		pr_err("Trying to register an i3c driver without probe callback\n");
267 		return -EINVAL;
268 	}
269 
270 	return driver_register(&drv->driver);
271 }
272 EXPORT_SYMBOL_GPL(i3c_driver_register_with_owner);
273 
274 /**
275  * i3c_driver_unregister() - unregister an I3C device driver
276  *
277  * @drv: driver to unregister
278  *
279  * Unregister @drv.
280  */
281 void i3c_driver_unregister(struct i3c_driver *drv)
282 {
283 	driver_unregister(&drv->driver);
284 }
285 EXPORT_SYMBOL_GPL(i3c_driver_unregister);
286