xref: /linux/drivers/mfd/mfd-core.c (revision 5ea5880764cbb164afb17a62e76ca75dc371409d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * drivers/mfd/mfd-core.c
4  *
5  * core MFD support
6  * Copyright (c) 2006 Ian Molton
7  * Copyright (c) 2007,2008 Dmitry Baryshkov
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/platform_device.h>
12 #include <linux/acpi.h>
13 #include <linux/list.h>
14 #include <linux/property.h>
15 #include <linux/mfd/core.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <linux/irqdomain.h>
20 #include <linux/of.h>
21 #include <linux/of_address.h>
22 #include <linux/regulator/consumer.h>
23 
24 static LIST_HEAD(mfd_of_node_list);
25 static DEFINE_MUTEX(mfd_of_node_mutex);
26 
27 struct mfd_of_node_entry {
28 	struct list_head list;
29 	struct device *dev;
30 	struct device_node *np;
31 };
32 
33 static const struct device_type mfd_dev_type = {
34 	.name	= "mfd_device",
35 };
36 
37 #if IS_ENABLED(CONFIG_ACPI)
38 struct match_ids_walk_data {
39 	struct acpi_device_id *ids;
40 	struct acpi_device *adev;
41 };
42 
43 static int match_device_ids(struct acpi_device *adev, void *data)
44 {
45 	struct match_ids_walk_data *wd = data;
46 
47 	if (!acpi_match_device_ids(adev, wd->ids)) {
48 		wd->adev = adev;
49 		return 1;
50 	}
51 
52 	return 0;
53 }
54 
55 static void mfd_acpi_add_device(const struct mfd_cell *cell,
56 				struct platform_device *pdev)
57 {
58 	const struct mfd_cell_acpi_match *match = cell->acpi_match;
59 	struct acpi_device *adev = NULL;
60 	struct acpi_device *parent;
61 
62 	parent = ACPI_COMPANION(pdev->dev.parent);
63 	if (!parent)
64 		return;
65 
66 	/*
67 	 * MFD child device gets its ACPI handle either from the ACPI device
68 	 * directly under the parent that matches the either _HID or _CID, or
69 	 * _ADR or it will use the parent handle if is no ID is given.
70 	 *
71 	 * Note that use of _ADR is a grey area in the ACPI specification,
72 	 * though at least Intel Galileo Gen 2 is using it to distinguish
73 	 * the children devices.
74 	 */
75 	if (match) {
76 		if (match->pnpid) {
77 			struct acpi_device_id ids[2] = {};
78 			struct match_ids_walk_data wd = {
79 				.adev = NULL,
80 				.ids = ids,
81 			};
82 
83 			strscpy(ids[0].id, match->pnpid, sizeof(ids[0].id));
84 			acpi_dev_for_each_child(parent, match_device_ids, &wd);
85 			adev = wd.adev;
86 		} else {
87 			adev = acpi_find_child_device(parent, match->adr, false);
88 		}
89 	}
90 
91 	/*
92 	 * NOTE: The fwnode design doesn't allow proper stacking/sharing. This
93 	 * should eventually turn into a device fwnode API call that will allow
94 	 * prepending to a list of fwnodes (with ACPI taking precedence).
95 	 *
96 	 * set_primary_fwnode() is used here, instead of device_set_node(), as
97 	 * device_set_node() will overwrite the existing fwnode, which may be an
98 	 * OF node that was populated earlier. To support a use case where ACPI
99 	 * and OF is used in conjunction, we call set_primary_fwnode() instead.
100 	 */
101 	set_primary_fwnode(&pdev->dev, acpi_fwnode_handle(adev ?: parent));
102 }
103 #else
104 static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
105 				       struct platform_device *pdev)
106 {
107 }
108 #endif
109 
110 static int mfd_match_of_node_to_dev(struct platform_device *pdev,
111 				    struct device_node *np,
112 				    const struct mfd_cell *cell)
113 {
114 	struct mfd_of_node_entry *of_entry;
115 	u64 of_node_addr;
116 
117 	/* Skip if OF node has previously been allocated to a device */
118 	scoped_guard(mutex, &mfd_of_node_mutex) {
119 		list_for_each_entry(of_entry, &mfd_of_node_list, list)
120 			if (of_entry->np == np)
121 				return -EAGAIN;
122 	}
123 
124 	if (!cell->use_of_reg)
125 		/* No of_reg defined - allocate first free compatible match */
126 		goto allocate_of_node;
127 
128 	/* We only care about each node's first defined address */
129 	if (of_property_read_reg(np, 0, &of_node_addr, NULL))
130 		/* OF node does not contatin a 'reg' property to match to */
131 		return -EAGAIN;
132 
133 	if (cell->of_reg != of_node_addr)
134 		/* No match */
135 		return -EAGAIN;
136 
137 allocate_of_node:
138 	of_entry = kzalloc(sizeof(*of_entry), GFP_KERNEL);
139 	if (!of_entry)
140 		return -ENOMEM;
141 
142 	of_entry->dev = &pdev->dev;
143 	of_entry->np = of_node_get(np);
144 	scoped_guard(mutex, &mfd_of_node_mutex)
145 		list_add_tail(&of_entry->list, &mfd_of_node_list);
146 
147 	device_set_node(&pdev->dev, of_fwnode_handle(np));
148 	return 0;
149 }
150 
151 static int mfd_add_device(struct device *parent, int id,
152 			  const struct mfd_cell *cell,
153 			  struct resource *mem_base,
154 			  int irq_base, struct irq_domain *domain)
155 {
156 	struct resource *res;
157 	struct platform_device *pdev;
158 	struct mfd_of_node_entry *of_entry, *tmp;
159 	bool disabled = false;
160 	int ret = -ENOMEM;
161 	int platform_id;
162 	int r;
163 
164 	if (id == PLATFORM_DEVID_AUTO)
165 		platform_id = id;
166 	else
167 		platform_id = id + cell->id;
168 
169 	pdev = platform_device_alloc(cell->name, platform_id);
170 	if (!pdev)
171 		goto fail_alloc;
172 
173 	pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
174 	if (!pdev->mfd_cell)
175 		goto fail_device;
176 
177 	res = kcalloc(cell->num_resources, sizeof(*res), GFP_KERNEL);
178 	if (!res)
179 		goto fail_device;
180 
181 	pdev->dev.parent = parent;
182 	pdev->dev.type = &mfd_dev_type;
183 	pdev->dev.dma_mask = parent->dma_mask;
184 	pdev->dev.dma_parms = parent->dma_parms;
185 	pdev->dev.coherent_dma_mask = parent->coherent_dma_mask;
186 
187 	ret = regulator_bulk_register_supply_alias(
188 			&pdev->dev, cell->parent_supplies,
189 			parent, cell->parent_supplies,
190 			cell->num_parent_supplies);
191 	if (ret < 0)
192 		goto fail_res;
193 
194 	if (IS_ENABLED(CONFIG_OF) && parent->of_node && cell->of_compatible) {
195 		for_each_child_of_node_scoped(parent->of_node, np) {
196 			if (of_device_is_compatible(np, cell->of_compatible)) {
197 				/* Skip 'disabled' devices */
198 				if (!of_device_is_available(np)) {
199 					disabled = true;
200 					continue;
201 				}
202 
203 				ret = mfd_match_of_node_to_dev(pdev, np, cell);
204 				if (ret == -EAGAIN)
205 					continue;
206 				if (ret)
207 					goto fail_alias;
208 
209 				goto match;
210 			}
211 		}
212 
213 		if (disabled) {
214 			/* Ignore 'disabled' devices error free */
215 			ret = 0;
216 			goto fail_alias;
217 		}
218 
219 match:
220 		if (!pdev->dev.of_node)
221 			pr_warn("%s: Failed to locate of_node [id: %d]\n",
222 				cell->name, platform_id);
223 	}
224 
225 	mfd_acpi_add_device(cell, pdev);
226 
227 	if (cell->pdata_size) {
228 		ret = platform_device_add_data(pdev,
229 					cell->platform_data, cell->pdata_size);
230 		if (ret)
231 			goto fail_of_entry;
232 	}
233 
234 	if (cell->swnode) {
235 		ret = device_add_software_node(&pdev->dev, cell->swnode);
236 		if (ret)
237 			goto fail_of_entry;
238 	}
239 
240 	for (r = 0; r < cell->num_resources; r++) {
241 		res[r].name = cell->resources[r].name;
242 		res[r].flags = cell->resources[r].flags;
243 
244 		/* Find out base to use */
245 		if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
246 			res[r].parent = mem_base;
247 			res[r].start = mem_base->start +
248 				cell->resources[r].start;
249 			res[r].end = mem_base->start +
250 				cell->resources[r].end;
251 		} else if (cell->resources[r].flags & IORESOURCE_IRQ) {
252 			if (domain) {
253 				/* Unable to create mappings for IRQ ranges. */
254 				WARN_ON(cell->resources[r].start !=
255 					cell->resources[r].end);
256 				res[r].start = res[r].end = irq_create_mapping(
257 					domain, cell->resources[r].start);
258 			} else {
259 				res[r].start = irq_base +
260 					cell->resources[r].start;
261 				res[r].end   = irq_base +
262 					cell->resources[r].end;
263 			}
264 		} else {
265 			res[r].parent = cell->resources[r].parent;
266 			res[r].start = cell->resources[r].start;
267 			res[r].end   = cell->resources[r].end;
268 		}
269 
270 		if (!cell->ignore_resource_conflicts) {
271 			if (has_acpi_companion(&pdev->dev)) {
272 				ret = acpi_check_resource_conflict(&res[r]);
273 				if (ret)
274 					goto fail_res_conflict;
275 			}
276 		}
277 	}
278 
279 	ret = platform_device_add_resources(pdev, res, cell->num_resources);
280 	if (ret)
281 		goto fail_res_conflict;
282 
283 	ret = platform_device_add(pdev);
284 	if (ret)
285 		goto fail_res_conflict;
286 
287 	if (cell->pm_runtime_no_callbacks)
288 		pm_runtime_no_callbacks(&pdev->dev);
289 
290 	kfree(res);
291 
292 	return 0;
293 
294 fail_res_conflict:
295 	if (cell->swnode)
296 		device_remove_software_node(&pdev->dev);
297 fail_of_entry:
298 	scoped_guard(mutex, &mfd_of_node_mutex) {
299 		list_for_each_entry_safe(of_entry, tmp, &mfd_of_node_list, list)
300 			if (of_entry->dev == &pdev->dev) {
301 				list_del(&of_entry->list);
302 				kfree(of_entry);
303 			}
304 	}
305 fail_alias:
306 	regulator_bulk_unregister_supply_alias(&pdev->dev,
307 					       cell->parent_supplies,
308 					       cell->num_parent_supplies);
309 fail_res:
310 	kfree(res);
311 fail_device:
312 	platform_device_put(pdev);
313 fail_alloc:
314 	return ret;
315 }
316 
317 /**
318  * mfd_add_devices - register child devices
319  *
320  * @parent:	Pointer to parent device.
321  * @id:		Can be PLATFORM_DEVID_AUTO to let the Platform API take care
322  *		of device numbering, or will be added to a device's cell_id.
323  * @cells:	Array of (struct mfd_cell)s describing child devices.
324  * @n_devs:	Number of child devices to register.
325  * @mem_base:	Parent register range resource for child devices.
326  * @irq_base:	Base of the range of virtual interrupt numbers allocated for
327  *		this MFD device. Unused if @domain is specified.
328  * @domain:	Interrupt domain to create mappings for hardware interrupts.
329  */
330 int mfd_add_devices(struct device *parent, int id,
331 		    const struct mfd_cell *cells, int n_devs,
332 		    struct resource *mem_base,
333 		    int irq_base, struct irq_domain *domain)
334 {
335 	int i;
336 	int ret;
337 
338 	for (i = 0; i < n_devs; i++) {
339 		ret = mfd_add_device(parent, id, cells + i, mem_base,
340 				     irq_base, domain);
341 		if (ret)
342 			goto fail;
343 	}
344 
345 	return 0;
346 
347 fail:
348 	if (i)
349 		mfd_remove_devices(parent);
350 
351 	return ret;
352 }
353 EXPORT_SYMBOL(mfd_add_devices);
354 
355 static int mfd_remove_devices_fn(struct device *dev, void *data)
356 {
357 	struct platform_device *pdev;
358 	const struct mfd_cell *cell;
359 	struct mfd_of_node_entry *of_entry, *tmp;
360 	int *level = data;
361 
362 	if (dev->type != &mfd_dev_type)
363 		return 0;
364 
365 	pdev = to_platform_device(dev);
366 	cell = mfd_get_cell(pdev);
367 
368 	if (level && cell->level > *level)
369 		return 0;
370 
371 	if (cell->swnode)
372 		device_remove_software_node(&pdev->dev);
373 
374 	scoped_guard(mutex, &mfd_of_node_mutex) {
375 		list_for_each_entry_safe(of_entry, tmp, &mfd_of_node_list, list)
376 			if (of_entry->dev == &pdev->dev) {
377 				list_del(&of_entry->list);
378 				kfree(of_entry);
379 			}
380 	}
381 
382 	regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,
383 					       cell->num_parent_supplies);
384 
385 	platform_device_unregister(pdev);
386 	return 0;
387 }
388 
389 void mfd_remove_devices_late(struct device *parent)
390 {
391 	int level = MFD_DEP_LEVEL_HIGH;
392 
393 	device_for_each_child_reverse(parent, &level, mfd_remove_devices_fn);
394 }
395 EXPORT_SYMBOL(mfd_remove_devices_late);
396 
397 void mfd_remove_devices(struct device *parent)
398 {
399 	int level = MFD_DEP_LEVEL_NORMAL;
400 
401 	device_for_each_child_reverse(parent, &level, mfd_remove_devices_fn);
402 }
403 EXPORT_SYMBOL(mfd_remove_devices);
404 
405 static void devm_mfd_dev_release(struct device *dev, void *res)
406 {
407 	mfd_remove_devices(dev);
408 }
409 
410 /**
411  * devm_mfd_add_devices - Resource managed version of mfd_add_devices()
412  *
413  * Returns 0 on success or an appropriate negative error number on failure.
414  * All child-devices of the MFD will automatically be removed when it gets
415  * unbinded.
416  *
417  * @dev:	Pointer to parent device.
418  * @id:		Can be PLATFORM_DEVID_AUTO to let the Platform API take care
419  *		of device numbering, or will be added to a device's cell_id.
420  * @cells:	Array of (struct mfd_cell)s describing child devices.
421  * @n_devs:	Number of child devices to register.
422  * @mem_base:	Parent register range resource for child devices.
423  * @irq_base:	Base of the range of virtual interrupt numbers allocated for
424  *		this MFD device. Unused if @domain is specified.
425  * @domain:	Interrupt domain to create mappings for hardware interrupts.
426  */
427 int devm_mfd_add_devices(struct device *dev, int id,
428 			 const struct mfd_cell *cells, int n_devs,
429 			 struct resource *mem_base,
430 			 int irq_base, struct irq_domain *domain)
431 {
432 	struct device **ptr;
433 	int ret;
434 
435 	ptr = devres_alloc(devm_mfd_dev_release, sizeof(*ptr), GFP_KERNEL);
436 	if (!ptr)
437 		return -ENOMEM;
438 
439 	ret = mfd_add_devices(dev, id, cells, n_devs, mem_base,
440 			      irq_base, domain);
441 	if (ret < 0) {
442 		devres_free(ptr);
443 		return ret;
444 	}
445 
446 	*ptr = dev;
447 	devres_add(dev, ptr);
448 
449 	return ret;
450 }
451 EXPORT_SYMBOL(devm_mfd_add_devices);
452 
453 MODULE_DESCRIPTION("Core MFD support");
454 MODULE_LICENSE("GPL");
455 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");
456