1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Test managed platform driver
4 */
5
6 #include <linux/completion.h>
7 #include <linux/device/bus.h>
8 #include <linux/device/driver.h>
9 #include <linux/platform_device.h>
10
11 #include <kunit/platform_device.h>
12 #include <kunit/resource.h>
13
14 struct kunit_platform_device_alloc_params {
15 const char *name;
16 int id;
17 };
18
19 static int kunit_platform_device_alloc_init(struct kunit_resource *res, void *context)
20 {
21 struct kunit_platform_device_alloc_params *params = context;
22 struct platform_device *pdev;
23
24 pdev = platform_device_alloc(params->name, params->id);
25 if (!pdev)
26 return -ENOMEM;
27
28 res->data = pdev;
29
30 return 0;
31 }
32
33 static void kunit_platform_device_alloc_exit(struct kunit_resource *res)
34 {
35 struct platform_device *pdev = res->data;
36
37 platform_device_put(pdev);
38 }
39
40 /**
41 * kunit_platform_device_alloc() - Allocate a KUnit test managed platform device
42 * @test: test context
43 * @name: device name of platform device to alloc
44 * @id: identifier of platform device to alloc.
45 *
46 * Allocate a test managed platform device. The device is put when the test completes.
47 *
48 * Return: Allocated platform device on success, NULL on failure.
49 */
50 struct platform_device *
51 kunit_platform_device_alloc(struct kunit *test, const char *name, int id)
52 {
53 struct kunit_platform_device_alloc_params params = {
54 .name = name,
55 .id = id,
56 };
57
58 return kunit_alloc_resource(test,
59 kunit_platform_device_alloc_init,
60 kunit_platform_device_alloc_exit,
61 GFP_KERNEL, ¶ms);
62 }
63 EXPORT_SYMBOL_GPL(kunit_platform_device_alloc);
64
65 static void kunit_platform_device_add_exit(struct kunit_resource *res)
66 {
67 struct platform_device *pdev = res->data;
68
69 platform_device_unregister(pdev);
70 }
71
72 static bool
73 kunit_platform_device_alloc_match(struct kunit *test,
74 struct kunit_resource *res, void *match_data)
75 {
76 struct platform_device *pdev = match_data;
77
78 return res->data == pdev && res->free == kunit_platform_device_alloc_exit;
79 }
80
81 KUNIT_DEFINE_ACTION_WRAPPER(platform_device_unregister_wrapper,
82 platform_device_unregister, struct platform_device *);
83 /**
84 * kunit_platform_device_add() - Register a KUnit test managed platform device
85 * @test: test context
86 * @pdev: platform device to add
87 *
88 * Register a test managed platform device. The device is unregistered when the
89 * test completes.
90 *
91 * Return: 0 on success, negative errno on failure.
92 */
93 int kunit_platform_device_add(struct kunit *test, struct platform_device *pdev)
94 {
95 struct kunit_resource *res;
96 int ret;
97
98 ret = platform_device_add(pdev);
99 if (ret)
100 return ret;
101
102 res = kunit_find_resource(test, kunit_platform_device_alloc_match, pdev);
103 if (res) {
104 /*
105 * Transfer the reference count of the platform device if it
106 * was allocated with kunit_platform_device_alloc(). In this
107 * case, calling platform_device_put() when the test exits from
108 * kunit_platform_device_alloc_exit() would lead to reference
109 * count underflow because platform_device_unregister_wrapper()
110 * calls platform_device_unregister() which also calls
111 * platform_device_put().
112 *
113 * Usually callers transfer the refcount initialized in
114 * platform_device_alloc() to platform_device_add() by calling
115 * platform_device_unregister() when platform_device_add()
116 * succeeds or platform_device_put() when it fails. KUnit has to
117 * keep this straight by redirecting the free routine for the
118 * resource to the right function. Luckily this only has to
119 * account for the success scenario.
120 */
121 res->free = kunit_platform_device_add_exit;
122 kunit_put_resource(res);
123 } else {
124 ret = kunit_add_action_or_reset(test, platform_device_unregister_wrapper, pdev);
125 if (ret)
126 return ret;
127 }
128
129 return 0;
130 }
131 EXPORT_SYMBOL_GPL(kunit_platform_device_add);
132
133 struct kunit_platform_device_probe_nb {
134 struct completion *x;
135 struct device *dev;
136 struct notifier_block nb;
137 };
138
139 static int kunit_platform_device_probe_notify(struct notifier_block *nb,
140 unsigned long event, void *data)
141 {
142 struct kunit_platform_device_probe_nb *knb;
143 struct device *dev = data;
144
145 knb = container_of(nb, struct kunit_platform_device_probe_nb, nb);
146 if (event != BUS_NOTIFY_BOUND_DRIVER || knb->dev != dev)
147 return NOTIFY_DONE;
148
149 complete(knb->x);
150
151 return NOTIFY_OK;
152 }
153
154 static void kunit_platform_device_probe_nb_remove(void *nb)
155 {
156 bus_unregister_notifier(&platform_bus_type, nb);
157 }
158
159 /**
160 * kunit_platform_device_prepare_wait_for_probe() - Prepare a completion
161 * variable to wait for a platform device to probe
162 * @test: test context
163 * @pdev: platform device to prepare to wait for probe of
164 * @x: completion variable completed when @dev has probed
165 *
166 * Prepare a completion variable @x to wait for @pdev to probe. Waiting on the
167 * completion forces a preemption, allowing the platform driver to probe.
168 *
169 * Example
170 *
171 * .. code-block:: c
172 *
173 * static int kunit_platform_driver_probe(struct platform_device *pdev)
174 * {
175 * return 0;
176 * }
177 *
178 * static void kunit_platform_driver_test(struct kunit *test)
179 * {
180 * struct platform_device *pdev;
181 * struct platform_driver *pdrv;
182 * DECLARE_COMPLETION_ONSTACK(comp);
183 *
184 * pdev = kunit_platform_device_alloc(test, "kunit-platform", -1);
185 * KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
186 * KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_add(test, pdev));
187 *
188 * pdrv = kunit_kzalloc(test, sizeof(*pdrv), GFP_KERNEL);
189 * KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdrv);
190 *
191 * pdrv->probe = kunit_platform_driver_probe;
192 * pdrv->driver.name = "kunit-platform";
193 * pdrv->driver.owner = THIS_MODULE;
194 *
195 * KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_prepare_wait_for_probe(test, pdev, &comp));
196 * KUNIT_ASSERT_EQ(test, 0, kunit_platform_driver_register(test, pdrv));
197 *
198 * KUNIT_EXPECT_NE(test, 0, wait_for_completion_timeout(&comp, 3 * HZ));
199 * }
200 *
201 * Return: 0 on success, negative errno on failure.
202 */
203 int kunit_platform_device_prepare_wait_for_probe(struct kunit *test,
204 struct platform_device *pdev,
205 struct completion *x)
206 {
207 struct device *dev = &pdev->dev;
208 struct kunit_platform_device_probe_nb *knb;
209 bool bound;
210
211 knb = kunit_kzalloc(test, sizeof(*knb), GFP_KERNEL);
212 if (!knb)
213 return -ENOMEM;
214
215 knb->nb.notifier_call = kunit_platform_device_probe_notify;
216 knb->dev = dev;
217 knb->x = x;
218
219 device_lock(dev);
220 bound = device_is_bound(dev);
221 if (bound) {
222 device_unlock(dev);
223 complete(x);
224 kunit_kfree(test, knb);
225 return 0;
226 }
227
228 bus_register_notifier(&platform_bus_type, &knb->nb);
229 device_unlock(&pdev->dev);
230
231 return kunit_add_action_or_reset(test, kunit_platform_device_probe_nb_remove, &knb->nb);
232 }
233 EXPORT_SYMBOL_GPL(kunit_platform_device_prepare_wait_for_probe);
234
235 KUNIT_DEFINE_ACTION_WRAPPER(platform_driver_unregister_wrapper,
236 platform_driver_unregister, struct platform_driver *);
237 /**
238 * kunit_platform_driver_register() - Register a KUnit test managed platform driver
239 * @test: test context
240 * @drv: platform driver to register
241 *
242 * Register a test managed platform driver. This allows callers to embed the
243 * @drv in a container structure and use container_of() in the probe function
244 * to pass information to KUnit tests.
245 *
246 * Example
247 *
248 * .. code-block:: c
249 *
250 * struct kunit_test_context {
251 * struct platform_driver pdrv;
252 * const char *data;
253 * };
254 *
255 * static inline struct kunit_test_context *
256 * to_test_context(struct platform_device *pdev)
257 * {
258 * return container_of(to_platform_driver(pdev->dev.driver),
259 * struct kunit_test_context,
260 * pdrv);
261 * }
262 *
263 * static int kunit_platform_driver_probe(struct platform_device *pdev)
264 * {
265 * struct kunit_test_context *ctx;
266 *
267 * ctx = to_test_context(pdev);
268 * ctx->data = "test data";
269 *
270 * return 0;
271 * }
272 *
273 * static void kunit_platform_driver_test(struct kunit *test)
274 * {
275 * struct kunit_test_context *ctx;
276 *
277 * ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
278 * KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
279 *
280 * ctx->pdrv.probe = kunit_platform_driver_probe;
281 * ctx->pdrv.driver.name = "kunit-platform";
282 * ctx->pdrv.driver.owner = THIS_MODULE;
283 *
284 * KUNIT_EXPECT_EQ(test, 0, kunit_platform_driver_register(test, &ctx->pdrv));
285 * <... wait for driver to probe ...>
286 * KUNIT_EXPECT_STREQ(test, ctx->data, "test data");
287 * }
288 *
289 * Return: 0 on success, negative errno on failure.
290 */
291 int kunit_platform_driver_register(struct kunit *test,
292 struct platform_driver *drv)
293 {
294 int ret;
295
296 ret = platform_driver_register(drv);
297 if (ret)
298 return ret;
299
300 return kunit_add_action_or_reset(test, platform_driver_unregister_wrapper, drv);
301 }
302 EXPORT_SYMBOL_GPL(kunit_platform_driver_register);
303
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