xref: /openbmc/linux/drivers/mfd/mfd-core.c (revision d0bd7f2a) 
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/mfd/core.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <linux/irqdomain.h>
22 #include <linux/of.h>
23 #include <linux/regulator/consumer.h>
24 
25 static struct device_type mfd_dev_type = {
26 	.name	= "mfd_device",
27 };
28 
29 int mfd_cell_enable(struct platform_device *pdev)
30 {
31 	const struct mfd_cell *cell = mfd_get_cell(pdev);
32 	int err = 0;
33 
34 	/* only call enable hook if the cell wasn't previously enabled */
35 	if (atomic_inc_return(cell->usage_count) == 1)
36 		err = cell->enable(pdev);
37 
38 	/* if the enable hook failed, decrement counter to allow retries */
39 	if (err)
40 		atomic_dec(cell->usage_count);
41 
42 	return err;
43 }
44 EXPORT_SYMBOL(mfd_cell_enable);
45 
46 int mfd_cell_disable(struct platform_device *pdev)
47 {
48 	const struct mfd_cell *cell = mfd_get_cell(pdev);
49 	int err = 0;
50 
51 	/* only disable if no other clients are using it */
52 	if (atomic_dec_return(cell->usage_count) == 0)
53 		err = cell->disable(pdev);
54 
55 	/* if the disable hook failed, increment to allow retries */
56 	if (err)
57 		atomic_inc(cell->usage_count);
58 
59 	/* sanity check; did someone call disable too many times? */
60 	WARN_ON(atomic_read(cell->usage_count) < 0);
61 
62 	return err;
63 }
64 EXPORT_SYMBOL(mfd_cell_disable);
65 
66 static int mfd_platform_add_cell(struct platform_device *pdev,
67 				 const struct mfd_cell *cell,
68 				 atomic_t *usage_count)
69 {
70 	if (!cell)
71 		return 0;
72 
73 	pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
74 	if (!pdev->mfd_cell)
75 		return -ENOMEM;
76 
77 	pdev->mfd_cell->usage_count = usage_count;
78 	return 0;
79 }
80 
81 #if IS_ENABLED(CONFIG_ACPI)
82 static void mfd_acpi_add_device(const struct mfd_cell *cell,
83 				struct platform_device *pdev)
84 {
85 	struct acpi_device *parent_adev;
86 	struct acpi_device *adev;
87 
88 	parent_adev = ACPI_COMPANION(pdev->dev.parent);
89 	if (!parent_adev)
90 		return;
91 
92 	/*
93 	 * MFD child device gets its ACPI handle either from the ACPI
94 	 * device directly under the parent that matches the acpi_pnpid or
95 	 * it will use the parent handle if is no acpi_pnpid is given.
96 	 */
97 	adev = parent_adev;
98 	if (cell->acpi_pnpid) {
99 		struct acpi_device_id ids[2] = {};
100 		struct acpi_device *child_adev;
101 
102 		strlcpy(ids[0].id, cell->acpi_pnpid, sizeof(ids[0].id));
103 		list_for_each_entry(child_adev, &parent_adev->children, node)
104 			if (acpi_match_device_ids(child_adev, ids)) {
105 				adev = child_adev;
106 				break;
107 			}
108 	}
109 
110 	ACPI_COMPANION_SET(&pdev->dev, adev);
111 }
112 #else
113 static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
114 				       struct platform_device *pdev)
115 {
116 }
117 #endif
118 
119 static int mfd_add_device(struct device *parent, int id,
120 			  const struct mfd_cell *cell, atomic_t *usage_count,
121 			  struct resource *mem_base,
122 			  int irq_base, struct irq_domain *domain)
123 {
124 	struct resource *res;
125 	struct platform_device *pdev;
126 	struct device_node *np = NULL;
127 	int ret = -ENOMEM;
128 	int platform_id;
129 	int r;
130 
131 	if (id == PLATFORM_DEVID_AUTO)
132 		platform_id = id;
133 	else
134 		platform_id = id + cell->id;
135 
136 	pdev = platform_device_alloc(cell->name, platform_id);
137 	if (!pdev)
138 		goto fail_alloc;
139 
140 	res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
141 	if (!res)
142 		goto fail_device;
143 
144 	pdev->dev.parent = parent;
145 	pdev->dev.type = &mfd_dev_type;
146 	pdev->dev.dma_mask = parent->dma_mask;
147 	pdev->dev.dma_parms = parent->dma_parms;
148 	pdev->dev.coherent_dma_mask = parent->coherent_dma_mask;
149 
150 	ret = regulator_bulk_register_supply_alias(
151 			&pdev->dev, cell->parent_supplies,
152 			parent, cell->parent_supplies,
153 			cell->num_parent_supplies);
154 	if (ret < 0)
155 		goto fail_res;
156 
157 	if (parent->of_node && cell->of_compatible) {
158 		for_each_child_of_node(parent->of_node, np) {
159 			if (of_device_is_compatible(np, cell->of_compatible)) {
160 				pdev->dev.of_node = np;
161 				break;
162 			}
163 		}
164 	}
165 
166 	mfd_acpi_add_device(cell, pdev);
167 
168 	if (cell->pdata_size) {
169 		ret = platform_device_add_data(pdev,
170 					cell->platform_data, cell->pdata_size);
171 		if (ret)
172 			goto fail_alias;
173 	}
174 
175 	ret = mfd_platform_add_cell(pdev, cell, usage_count);
176 	if (ret)
177 		goto fail_alias;
178 
179 	for (r = 0; r < cell->num_resources; r++) {
180 		res[r].name = cell->resources[r].name;
181 		res[r].flags = cell->resources[r].flags;
182 
183 		/* Find out base to use */
184 		if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
185 			res[r].parent = mem_base;
186 			res[r].start = mem_base->start +
187 				cell->resources[r].start;
188 			res[r].end = mem_base->start +
189 				cell->resources[r].end;
190 		} else if (cell->resources[r].flags & IORESOURCE_IRQ) {
191 			if (domain) {
192 				/* Unable to create mappings for IRQ ranges. */
193 				WARN_ON(cell->resources[r].start !=
194 					cell->resources[r].end);
195 				res[r].start = res[r].end = irq_create_mapping(
196 					domain, cell->resources[r].start);
197 			} else {
198 				res[r].start = irq_base +
199 					cell->resources[r].start;
200 				res[r].end   = irq_base +
201 					cell->resources[r].end;
202 			}
203 		} else {
204 			res[r].parent = cell->resources[r].parent;
205 			res[r].start = cell->resources[r].start;
206 			res[r].end   = cell->resources[r].end;
207 		}
208 
209 		if (!cell->ignore_resource_conflicts) {
210 			ret = acpi_check_resource_conflict(&res[r]);
211 			if (ret)
212 				goto fail_alias;
213 		}
214 	}
215 
216 	ret = platform_device_add_resources(pdev, res, cell->num_resources);
217 	if (ret)
218 		goto fail_alias;
219 
220 	ret = platform_device_add(pdev);
221 	if (ret)
222 		goto fail_alias;
223 
224 	if (cell->pm_runtime_no_callbacks)
225 		pm_runtime_no_callbacks(&pdev->dev);
226 
227 	kfree(res);
228 
229 	return 0;
230 
231 fail_alias:
232 	regulator_bulk_unregister_supply_alias(&pdev->dev,
233 					       cell->parent_supplies,
234 					       cell->num_parent_supplies);
235 fail_res:
236 	kfree(res);
237 fail_device:
238 	platform_device_put(pdev);
239 fail_alloc:
240 	return ret;
241 }
242 
243 int mfd_add_devices(struct device *parent, int id,
244 		    const struct mfd_cell *cells, int n_devs,
245 		    struct resource *mem_base,
246 		    int irq_base, struct irq_domain *domain)
247 {
248 	int i;
249 	int ret;
250 	atomic_t *cnts;
251 
252 	/* initialize reference counting for all cells */
253 	cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
254 	if (!cnts)
255 		return -ENOMEM;
256 
257 	for (i = 0; i < n_devs; i++) {
258 		atomic_set(&cnts[i], 0);
259 		ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,
260 				     irq_base, domain);
261 		if (ret)
262 			goto fail;
263 	}
264 
265 	return 0;
266 
267 fail:
268 	if (i)
269 		mfd_remove_devices(parent);
270 	else
271 		kfree(cnts);
272 	return ret;
273 }
274 EXPORT_SYMBOL(mfd_add_devices);
275 
276 static int mfd_remove_devices_fn(struct device *dev, void *c)
277 {
278 	struct platform_device *pdev;
279 	const struct mfd_cell *cell;
280 	atomic_t **usage_count = c;
281 
282 	if (dev->type != &mfd_dev_type)
283 		return 0;
284 
285 	pdev = to_platform_device(dev);
286 	cell = mfd_get_cell(pdev);
287 
288 	regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,
289 					       cell->num_parent_supplies);
290 
291 	/* find the base address of usage_count pointers (for freeing) */
292 	if (!*usage_count || (cell->usage_count < *usage_count))
293 		*usage_count = cell->usage_count;
294 
295 	platform_device_unregister(pdev);
296 	return 0;
297 }
298 
299 void mfd_remove_devices(struct device *parent)
300 {
301 	atomic_t *cnts = NULL;
302 
303 	device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
304 	kfree(cnts);
305 }
306 EXPORT_SYMBOL(mfd_remove_devices);
307 
308 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
309 {
310 	struct mfd_cell cell_entry;
311 	struct device *dev;
312 	struct platform_device *pdev;
313 	int i;
314 
315 	/* fetch the parent cell's device (should already be registered!) */
316 	dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
317 	if (!dev) {
318 		printk(KERN_ERR "failed to find device for cell %s\n", cell);
319 		return -ENODEV;
320 	}
321 	pdev = to_platform_device(dev);
322 	memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
323 
324 	WARN_ON(!cell_entry.enable);
325 
326 	for (i = 0; i < n_clones; i++) {
327 		cell_entry.name = clones[i];
328 		/* don't give up if a single call fails; just report error */
329 		if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
330 				   cell_entry.usage_count, NULL, 0, NULL))
331 			dev_err(dev, "failed to create platform device '%s'\n",
332 					clones[i]);
333 	}
334 
335 	return 0;
336 }
337 EXPORT_SYMBOL(mfd_clone_cell);
338 
339 MODULE_LICENSE("GPL");
340 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");
341