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235 lines · 5.4 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2// Copyright (c) 2018-2021 Intel Corporation
3
4#include <linux/bug.h>
5#include <linux/device.h>
6#include <linux/export.h>
7#include <linux/idr.h>
8#include <linux/module.h>
9#include <linux/of.h>
10#include <linux/peci.h>
11#include <linux/pm_runtime.h>
12#include <linux/property.h>
13#include <linux/slab.h>
14
15#include "internal.h"
16
17static DEFINE_IDA(peci_controller_ida);
18
19static void peci_controller_dev_release(struct device *dev)
20{
21 struct peci_controller *controller = to_peci_controller(dev);
22
23 mutex_destroy(&controller->bus_lock);
24 ida_free(&peci_controller_ida, controller->id);
25 kfree(controller);
26}
27
28const struct device_type peci_controller_type = {
29 .release = peci_controller_dev_release,
30};
31
32int peci_controller_scan_devices(struct peci_controller *controller)
33{
34 int ret;
35 u8 addr;
36
37 for (addr = PECI_BASE_ADDR; addr < PECI_BASE_ADDR + PECI_DEVICE_NUM_MAX; addr++) {
38 ret = peci_device_create(controller, addr);
39 if (ret)
40 return ret;
41 }
42
43 return 0;
44}
45
46static struct peci_controller *peci_controller_alloc(struct device *dev,
47 const struct peci_controller_ops *ops)
48{
49 struct peci_controller *controller;
50 int ret;
51
52 if (!ops->xfer)
53 return ERR_PTR(-EINVAL);
54
55 controller = kzalloc_obj(*controller);
56 if (!controller)
57 return ERR_PTR(-ENOMEM);
58
59 ret = ida_alloc_max(&peci_controller_ida, U8_MAX, GFP_KERNEL);
60 if (ret < 0)
61 goto err;
62 controller->id = ret;
63
64 controller->ops = ops;
65
66 controller->dev.parent = dev;
67 controller->dev.bus = &peci_bus_type;
68 controller->dev.type = &peci_controller_type;
69
70 device_initialize(&controller->dev);
71
72 mutex_init(&controller->bus_lock);
73
74 return controller;
75
76err:
77 kfree(controller);
78 return ERR_PTR(ret);
79}
80
81static int unregister_child(struct device *dev, void *dummy)
82{
83 peci_device_destroy(to_peci_device(dev));
84
85 return 0;
86}
87
88static void unregister_controller(void *_controller)
89{
90 struct peci_controller *controller = _controller;
91
92 /*
93 * Detach any active PECI devices. This can't fail, thus we do not
94 * check the returned value.
95 */
96 device_for_each_child_reverse(&controller->dev, NULL, unregister_child);
97
98 device_unregister(&controller->dev);
99
100 fwnode_handle_put(controller->dev.fwnode);
101
102 pm_runtime_disable(&controller->dev);
103}
104
105/**
106 * devm_peci_controller_add() - add PECI controller
107 * @dev: device for devm operations
108 * @ops: pointer to controller specific methods
109 *
110 * In final stage of its probe(), peci_controller driver calls
111 * devm_peci_controller_add() to register itself with the PECI bus.
112 *
113 * Return: Pointer to the newly allocated controller or ERR_PTR() in case of failure.
114 */
115struct peci_controller *devm_peci_controller_add(struct device *dev,
116 const struct peci_controller_ops *ops)
117{
118 struct peci_controller *controller;
119 int ret;
120
121 controller = peci_controller_alloc(dev, ops);
122 if (IS_ERR(controller))
123 return controller;
124
125 ret = dev_set_name(&controller->dev, "peci-%d", controller->id);
126 if (ret)
127 goto err_put;
128
129 pm_runtime_no_callbacks(&controller->dev);
130 pm_suspend_ignore_children(&controller->dev, true);
131 pm_runtime_enable(&controller->dev);
132
133 device_set_node(&controller->dev, fwnode_handle_get(dev_fwnode(dev)));
134
135 ret = device_add(&controller->dev);
136 if (ret)
137 goto err_fwnode;
138
139 ret = devm_add_action_or_reset(dev, unregister_controller, controller);
140 if (ret)
141 return ERR_PTR(ret);
142
143 /*
144 * Ignoring retval since failures during scan are non-critical for
145 * controller itself.
146 */
147 peci_controller_scan_devices(controller);
148
149 return controller;
150
151err_fwnode:
152 fwnode_handle_put(controller->dev.fwnode);
153
154 pm_runtime_disable(&controller->dev);
155
156err_put:
157 put_device(&controller->dev);
158
159 return ERR_PTR(ret);
160}
161EXPORT_SYMBOL_NS_GPL(devm_peci_controller_add, "PECI");
162
163static const struct peci_device_id *
164peci_bus_match_device_id(const struct peci_device_id *id, struct peci_device *device)
165{
166 while (id->x86_vfm != 0) {
167 if (id->x86_vfm == device->info.x86_vfm)
168 return id;
169 id++;
170 }
171
172 return NULL;
173}
174
175static int peci_bus_device_match(struct device *dev, const struct device_driver *drv)
176{
177 struct peci_device *device = to_peci_device(dev);
178 const struct peci_driver *peci_drv = to_peci_driver(drv);
179
180 if (dev->type != &peci_device_type)
181 return 0;
182
183 return !!peci_bus_match_device_id(peci_drv->id_table, device);
184}
185
186static int peci_bus_device_probe(struct device *dev)
187{
188 struct peci_device *device = to_peci_device(dev);
189 struct peci_driver *driver = to_peci_driver(dev->driver);
190
191 return driver->probe(device, peci_bus_match_device_id(driver->id_table, device));
192}
193
194static void peci_bus_device_remove(struct device *dev)
195{
196 struct peci_device *device = to_peci_device(dev);
197 struct peci_driver *driver = to_peci_driver(dev->driver);
198
199 if (driver->remove)
200 driver->remove(device);
201}
202
203const struct bus_type peci_bus_type = {
204 .name = "peci",
205 .match = peci_bus_device_match,
206 .probe = peci_bus_device_probe,
207 .remove = peci_bus_device_remove,
208 .bus_groups = peci_bus_groups,
209};
210
211static int __init peci_init(void)
212{
213 int ret;
214
215 ret = bus_register(&peci_bus_type);
216 if (ret < 0) {
217 pr_err("peci: failed to register PECI bus type!\n");
218 return ret;
219 }
220
221 return 0;
222}
223module_init(peci_init);
224
225static void __exit peci_exit(void)
226{
227 bus_unregister(&peci_bus_type);
228}
229module_exit(peci_exit);
230
231MODULE_AUTHOR("Jason M Bills <[email protected]>");
232MODULE_AUTHOR("Jae Hyun Yoo <[email protected]>");
233MODULE_AUTHOR("Iwona Winiarska <[email protected]>");
234MODULE_DESCRIPTION("PECI bus core module");
235MODULE_LICENSE("GPL");