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