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1 /*
2  * drivers/mfd/mfd-core.c
3  *
4  * core MFD support
5  * Copyright (c) 2006 Ian Molton
6  * Copyright (c) 2007,2008 Dmitry Baryshkov
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/platform_device.h>
16 #include <linux/acpi.h>
17 #include <linux/property.h>
18 #include <linux/mfd/core.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/slab.h>
21 #include <linux/module.h>
22 #include <linux/irqdomain.h>
23 #include <linux/of.h>
24 #include <linux/regulator/consumer.h>
25 
26 static struct device_type mfd_dev_type = {
27 	.name	= "mfd_device",
28 };
29 
mfd_cell_enable(struct platform_device * pdev)30 int mfd_cell_enable(struct platform_device *pdev)
31 {
32 	const struct mfd_cell *cell = mfd_get_cell(pdev);
33 	int err = 0;
34 
35 	if (!cell->enable) {
36 		dev_dbg(&pdev->dev, "No .enable() call-back registered\n");
37 		return 0;
38 	}
39 
40 	/* only call enable hook if the cell wasn't previously enabled */
41 	if (atomic_inc_return(cell->usage_count) == 1)
42 		err = cell->enable(pdev);
43 
44 	/* if the enable hook failed, decrement counter to allow retries */
45 	if (err)
46 		atomic_dec(cell->usage_count);
47 
48 	return err;
49 }
50 EXPORT_SYMBOL(mfd_cell_enable);
51 
mfd_cell_disable(struct platform_device * pdev)52 int mfd_cell_disable(struct platform_device *pdev)
53 {
54 	const struct mfd_cell *cell = mfd_get_cell(pdev);
55 	int err = 0;
56 
57 	if (!cell->disable) {
58 		dev_dbg(&pdev->dev, "No .disable() call-back registered\n");
59 		return 0;
60 	}
61 
62 	/* only disable if no other clients are using it */
63 	if (atomic_dec_return(cell->usage_count) == 0)
64 		err = cell->disable(pdev);
65 
66 	/* if the disable hook failed, increment to allow retries */
67 	if (err)
68 		atomic_inc(cell->usage_count);
69 
70 	/* sanity check; did someone call disable too many times? */
71 	WARN_ON(atomic_read(cell->usage_count) < 0);
72 
73 	return err;
74 }
75 EXPORT_SYMBOL(mfd_cell_disable);
76 
mfd_platform_add_cell(struct platform_device * pdev,const struct mfd_cell * cell,atomic_t * usage_count)77 static int mfd_platform_add_cell(struct platform_device *pdev,
78 				 const struct mfd_cell *cell,
79 				 atomic_t *usage_count)
80 {
81 	if (!cell)
82 		return 0;
83 
84 	pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
85 	if (!pdev->mfd_cell)
86 		return -ENOMEM;
87 
88 	pdev->mfd_cell->usage_count = usage_count;
89 	return 0;
90 }
91 
92 #if IS_ENABLED(CONFIG_ACPI)
mfd_acpi_add_device(const struct mfd_cell * cell,struct platform_device * pdev)93 static void mfd_acpi_add_device(const struct mfd_cell *cell,
94 				struct platform_device *pdev)
95 {
96 	const struct mfd_cell_acpi_match *match = cell->acpi_match;
97 	struct acpi_device *parent, *child;
98 	struct acpi_device *adev;
99 
100 	parent = ACPI_COMPANION(pdev->dev.parent);
101 	if (!parent)
102 		return;
103 
104 	/*
105 	 * MFD child device gets its ACPI handle either from the ACPI device
106 	 * directly under the parent that matches the either _HID or _CID, or
107 	 * _ADR or it will use the parent handle if is no ID is given.
108 	 *
109 	 * Note that use of _ADR is a grey area in the ACPI specification,
110 	 * though Intel Galileo Gen2 is using it to distinguish the children
111 	 * devices.
112 	 */
113 	adev = parent;
114 	if (match) {
115 		if (match->pnpid) {
116 			struct acpi_device_id ids[2] = {};
117 
118 			strlcpy(ids[0].id, match->pnpid, sizeof(ids[0].id));
119 			list_for_each_entry(child, &parent->children, node) {
120 				if (!acpi_match_device_ids(child, ids)) {
121 					adev = child;
122 					break;
123 				}
124 			}
125 		} else {
126 			unsigned long long adr;
127 			acpi_status status;
128 
129 			list_for_each_entry(child, &parent->children, node) {
130 				status = acpi_evaluate_integer(child->handle,
131 							       "_ADR", NULL,
132 							       &adr);
133 				if (ACPI_SUCCESS(status) && match->adr == adr) {
134 					adev = child;
135 					break;
136 				}
137 			}
138 		}
139 	}
140 
141 	ACPI_COMPANION_SET(&pdev->dev, adev);
142 }
143 #else
mfd_acpi_add_device(const struct mfd_cell * cell,struct platform_device * pdev)144 static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
145 				       struct platform_device *pdev)
146 {
147 }
148 #endif
149 
mfd_add_device(struct device * parent,int id,const struct mfd_cell * cell,atomic_t * usage_count,struct resource * mem_base,int irq_base,struct irq_domain * domain)150 static int mfd_add_device(struct device *parent, int id,
151 			  const struct mfd_cell *cell, atomic_t *usage_count,
152 			  struct resource *mem_base,
153 			  int irq_base, struct irq_domain *domain)
154 {
155 	struct resource *res;
156 	struct platform_device *pdev;
157 	struct device_node *np = NULL;
158 	int ret = -ENOMEM;
159 	int platform_id;
160 	int r;
161 
162 	if (id == PLATFORM_DEVID_AUTO)
163 		platform_id = id;
164 	else
165 		platform_id = id + cell->id;
166 
167 	pdev = platform_device_alloc(cell->name, platform_id);
168 	if (!pdev)
169 		goto fail_alloc;
170 
171 	res = kcalloc(cell->num_resources, sizeof(*res), GFP_KERNEL);
172 	if (!res)
173 		goto fail_device;
174 
175 	pdev->dev.parent = parent;
176 	pdev->dev.type = &mfd_dev_type;
177 	pdev->dev.dma_mask = parent->dma_mask;
178 	pdev->dev.dma_parms = parent->dma_parms;
179 	pdev->dev.coherent_dma_mask = parent->coherent_dma_mask;
180 
181 	ret = regulator_bulk_register_supply_alias(
182 			&pdev->dev, cell->parent_supplies,
183 			parent, cell->parent_supplies,
184 			cell->num_parent_supplies);
185 	if (ret < 0)
186 		goto fail_res;
187 
188 	if (parent->of_node && cell->of_compatible) {
189 		for_each_child_of_node(parent->of_node, np) {
190 			if (of_device_is_compatible(np, cell->of_compatible)) {
191 				pdev->dev.of_node = np;
192 				pdev->dev.fwnode = &np->fwnode;
193 				break;
194 			}
195 		}
196 	}
197 
198 	mfd_acpi_add_device(cell, pdev);
199 
200 	if (cell->pdata_size) {
201 		ret = platform_device_add_data(pdev,
202 					cell->platform_data, cell->pdata_size);
203 		if (ret)
204 			goto fail_alias;
205 	}
206 
207 	if (cell->properties) {
208 		ret = platform_device_add_properties(pdev, cell->properties);
209 		if (ret)
210 			goto fail_alias;
211 	}
212 
213 	ret = mfd_platform_add_cell(pdev, cell, usage_count);
214 	if (ret)
215 		goto fail_alias;
216 
217 	for (r = 0; r < cell->num_resources; r++) {
218 		res[r].name = cell->resources[r].name;
219 		res[r].flags = cell->resources[r].flags;
220 
221 		/* Find out base to use */
222 		if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
223 			res[r].parent = mem_base;
224 			res[r].start = mem_base->start +
225 				cell->resources[r].start;
226 			res[r].end = mem_base->start +
227 				cell->resources[r].end;
228 		} else if (cell->resources[r].flags & IORESOURCE_IRQ) {
229 			if (domain) {
230 				/* Unable to create mappings for IRQ ranges. */
231 				WARN_ON(cell->resources[r].start !=
232 					cell->resources[r].end);
233 				res[r].start = res[r].end = irq_create_mapping(
234 					domain, cell->resources[r].start);
235 			} else {
236 				res[r].start = irq_base +
237 					cell->resources[r].start;
238 				res[r].end   = irq_base +
239 					cell->resources[r].end;
240 			}
241 		} else {
242 			res[r].parent = cell->resources[r].parent;
243 			res[r].start = cell->resources[r].start;
244 			res[r].end   = cell->resources[r].end;
245 		}
246 
247 		if (!cell->ignore_resource_conflicts) {
248 			if (has_acpi_companion(&pdev->dev)) {
249 				ret = acpi_check_resource_conflict(&res[r]);
250 				if (ret)
251 					goto fail_alias;
252 			}
253 		}
254 	}
255 
256 	ret = platform_device_add_resources(pdev, res, cell->num_resources);
257 	if (ret)
258 		goto fail_alias;
259 
260 	ret = platform_device_add(pdev);
261 	if (ret)
262 		goto fail_alias;
263 
264 	if (cell->pm_runtime_no_callbacks)
265 		pm_runtime_no_callbacks(&pdev->dev);
266 
267 	kfree(res);
268 
269 	return 0;
270 
271 fail_alias:
272 	regulator_bulk_unregister_supply_alias(&pdev->dev,
273 					       cell->parent_supplies,
274 					       cell->num_parent_supplies);
275 fail_res:
276 	kfree(res);
277 fail_device:
278 	platform_device_put(pdev);
279 fail_alloc:
280 	return ret;
281 }
282 
mfd_add_devices(struct device * parent,int id,const struct mfd_cell * cells,int n_devs,struct resource * mem_base,int irq_base,struct irq_domain * domain)283 int mfd_add_devices(struct device *parent, int id,
284 		    const struct mfd_cell *cells, int n_devs,
285 		    struct resource *mem_base,
286 		    int irq_base, struct irq_domain *domain)
287 {
288 	int i;
289 	int ret;
290 	atomic_t *cnts;
291 
292 	/* initialize reference counting for all cells */
293 	cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
294 	if (!cnts)
295 		return -ENOMEM;
296 
297 	for (i = 0; i < n_devs; i++) {
298 		atomic_set(&cnts[i], 0);
299 		ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,
300 				     irq_base, domain);
301 		if (ret)
302 			goto fail;
303 	}
304 
305 	return 0;
306 
307 fail:
308 	if (i)
309 		mfd_remove_devices(parent);
310 	else
311 		kfree(cnts);
312 	return ret;
313 }
314 EXPORT_SYMBOL(mfd_add_devices);
315 
mfd_remove_devices_fn(struct device * dev,void * c)316 static int mfd_remove_devices_fn(struct device *dev, void *c)
317 {
318 	struct platform_device *pdev;
319 	const struct mfd_cell *cell;
320 	atomic_t **usage_count = c;
321 
322 	if (dev->type != &mfd_dev_type)
323 		return 0;
324 
325 	pdev = to_platform_device(dev);
326 	cell = mfd_get_cell(pdev);
327 
328 	regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,
329 					       cell->num_parent_supplies);
330 
331 	/* find the base address of usage_count pointers (for freeing) */
332 	if (!*usage_count || (cell->usage_count < *usage_count))
333 		*usage_count = cell->usage_count;
334 
335 	platform_device_unregister(pdev);
336 	return 0;
337 }
338 
mfd_remove_devices(struct device * parent)339 void mfd_remove_devices(struct device *parent)
340 {
341 	atomic_t *cnts = NULL;
342 
343 	device_for_each_child_reverse(parent, &cnts, mfd_remove_devices_fn);
344 	kfree(cnts);
345 }
346 EXPORT_SYMBOL(mfd_remove_devices);
347 
devm_mfd_dev_release(struct device * dev,void * res)348 static void devm_mfd_dev_release(struct device *dev, void *res)
349 {
350 	mfd_remove_devices(dev);
351 }
352 
353 /**
354  * devm_mfd_add_devices - Resource managed version of mfd_add_devices()
355  *
356  * Returns 0 on success or an appropriate negative error number on failure.
357  * All child-devices of the MFD will automatically be removed when it gets
358  * unbinded.
359  */
devm_mfd_add_devices(struct device * dev,int id,const struct mfd_cell * cells,int n_devs,struct resource * mem_base,int irq_base,struct irq_domain * domain)360 int devm_mfd_add_devices(struct device *dev, int id,
361 			 const struct mfd_cell *cells, int n_devs,
362 			 struct resource *mem_base,
363 			 int irq_base, struct irq_domain *domain)
364 {
365 	struct device **ptr;
366 	int ret;
367 
368 	ptr = devres_alloc(devm_mfd_dev_release, sizeof(*ptr), GFP_KERNEL);
369 	if (!ptr)
370 		return -ENOMEM;
371 
372 	ret = mfd_add_devices(dev, id, cells, n_devs, mem_base,
373 			      irq_base, domain);
374 	if (ret < 0) {
375 		devres_free(ptr);
376 		return ret;
377 	}
378 
379 	*ptr = dev;
380 	devres_add(dev, ptr);
381 
382 	return ret;
383 }
384 EXPORT_SYMBOL(devm_mfd_add_devices);
385 
mfd_clone_cell(const char * cell,const char ** clones,size_t n_clones)386 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
387 {
388 	struct mfd_cell cell_entry;
389 	struct device *dev;
390 	struct platform_device *pdev;
391 	int i;
392 
393 	/* fetch the parent cell's device (should already be registered!) */
394 	dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
395 	if (!dev) {
396 		printk(KERN_ERR "failed to find device for cell %s\n", cell);
397 		return -ENODEV;
398 	}
399 	pdev = to_platform_device(dev);
400 	memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
401 
402 	WARN_ON(!cell_entry.enable);
403 
404 	for (i = 0; i < n_clones; i++) {
405 		cell_entry.name = clones[i];
406 		/* don't give up if a single call fails; just report error */
407 		if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
408 				   cell_entry.usage_count, NULL, 0, NULL))
409 			dev_err(dev, "failed to create platform device '%s'\n",
410 					clones[i]);
411 	}
412 
413 	put_device(dev);
414 
415 	return 0;
416 }
417 EXPORT_SYMBOL(mfd_clone_cell);
418 
419 MODULE_LICENSE("GPL");
420 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");
421