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[~andy/linux] / drivers / mfd / mfd-core.c
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
24 static struct device_type mfd_dev_type = {
25         .name   = "mfd_device",
26 };
27
28 int mfd_cell_enable(struct platform_device *pdev)
29 {
30         const struct mfd_cell *cell = mfd_get_cell(pdev);
31         int err = 0;
32
33         /* only call enable hook if the cell wasn't previously enabled */
34         if (atomic_inc_return(cell->usage_count) == 1)
35                 err = cell->enable(pdev);
36
37         /* if the enable hook failed, decrement counter to allow retries */
38         if (err)
39                 atomic_dec(cell->usage_count);
40
41         return err;
42 }
43 EXPORT_SYMBOL(mfd_cell_enable);
44
45 int mfd_cell_disable(struct platform_device *pdev)
46 {
47         const struct mfd_cell *cell = mfd_get_cell(pdev);
48         int err = 0;
49
50         /* only disable if no other clients are using it */
51         if (atomic_dec_return(cell->usage_count) == 0)
52                 err = cell->disable(pdev);
53
54         /* if the disable hook failed, increment to allow retries */
55         if (err)
56                 atomic_inc(cell->usage_count);
57
58         /* sanity check; did someone call disable too many times? */
59         WARN_ON(atomic_read(cell->usage_count) < 0);
60
61         return err;
62 }
63 EXPORT_SYMBOL(mfd_cell_disable);
64
65 static int mfd_platform_add_cell(struct platform_device *pdev,
66                                  const struct mfd_cell *cell)
67 {
68         if (!cell)
69                 return 0;
70
71         pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
72         if (!pdev->mfd_cell)
73                 return -ENOMEM;
74
75         return 0;
76 }
77
78 static int mfd_add_device(struct device *parent, int id,
79                           const struct mfd_cell *cell,
80                           struct resource *mem_base,
81                           int irq_base, struct irq_domain *domain)
82 {
83         struct resource *res;
84         struct platform_device *pdev;
85         struct device_node *np = NULL;
86         int ret = -ENOMEM;
87         int r;
88
89         pdev = platform_device_alloc(cell->name, id + cell->id);
90         if (!pdev)
91                 goto fail_alloc;
92
93         res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
94         if (!res)
95                 goto fail_device;
96
97         pdev->dev.parent = parent;
98         pdev->dev.type = &mfd_dev_type;
99
100         if (parent->of_node && cell->of_compatible) {
101                 for_each_child_of_node(parent->of_node, np) {
102                         if (of_device_is_compatible(np, cell->of_compatible)) {
103                                 pdev->dev.of_node = np;
104                                 break;
105                         }
106                 }
107         }
108
109         if (cell->pdata_size) {
110                 ret = platform_device_add_data(pdev,
111                                         cell->platform_data, cell->pdata_size);
112                 if (ret)
113                         goto fail_res;
114         }
115
116         ret = mfd_platform_add_cell(pdev, cell);
117         if (ret)
118                 goto fail_res;
119
120         for (r = 0; r < cell->num_resources; r++) {
121                 res[r].name = cell->resources[r].name;
122                 res[r].flags = cell->resources[r].flags;
123
124                 /* Find out base to use */
125                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
126                         res[r].parent = mem_base;
127                         res[r].start = mem_base->start +
128                                 cell->resources[r].start;
129                         res[r].end = mem_base->start +
130                                 cell->resources[r].end;
131                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
132                         if (domain) {
133                                 /* Unable to create mappings for IRQ ranges. */
134                                 WARN_ON(cell->resources[r].start !=
135                                         cell->resources[r].end);
136                                 res[r].start = res[r].end = irq_create_mapping(
137                                         domain, cell->resources[r].start);
138                         } else {
139                                 res[r].start = irq_base +
140                                         cell->resources[r].start;
141                                 res[r].end   = irq_base +
142                                         cell->resources[r].end;
143                         }
144                 } else {
145                         res[r].parent = cell->resources[r].parent;
146                         res[r].start = cell->resources[r].start;
147                         res[r].end   = cell->resources[r].end;
148                 }
149
150                 if (!cell->ignore_resource_conflicts) {
151                         ret = acpi_check_resource_conflict(&res[r]);
152                         if (ret)
153                                 goto fail_res;
154                 }
155         }
156
157         ret = platform_device_add_resources(pdev, res, cell->num_resources);
158         if (ret)
159                 goto fail_res;
160
161         ret = platform_device_add(pdev);
162         if (ret)
163                 goto fail_res;
164
165         if (cell->pm_runtime_no_callbacks)
166                 pm_runtime_no_callbacks(&pdev->dev);
167
168         kfree(res);
169
170         return 0;
171
172 fail_res:
173         kfree(res);
174 fail_device:
175         platform_device_put(pdev);
176 fail_alloc:
177         return ret;
178 }
179
180 int mfd_add_devices(struct device *parent, int id,
181                     struct mfd_cell *cells, int n_devs,
182                     struct resource *mem_base,
183                     int irq_base, struct irq_domain *domain)
184 {
185         int i;
186         int ret = 0;
187         atomic_t *cnts;
188
189         /* initialize reference counting for all cells */
190         cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
191         if (!cnts)
192                 return -ENOMEM;
193
194         for (i = 0; i < n_devs; i++) {
195                 atomic_set(&cnts[i], 0);
196                 cells[i].usage_count = &cnts[i];
197                 ret = mfd_add_device(parent, id, cells + i, mem_base,
198                                      irq_base, domain);
199                 if (ret)
200                         break;
201         }
202
203         if (ret)
204                 mfd_remove_devices(parent);
205
206         return ret;
207 }
208 EXPORT_SYMBOL(mfd_add_devices);
209
210 static int mfd_remove_devices_fn(struct device *dev, void *c)
211 {
212         struct platform_device *pdev;
213         const struct mfd_cell *cell;
214         atomic_t **usage_count = c;
215
216         if (dev->type != &mfd_dev_type)
217                 return 0;
218
219         pdev = to_platform_device(dev);
220         cell = mfd_get_cell(pdev);
221
222         /* find the base address of usage_count pointers (for freeing) */
223         if (!*usage_count || (cell->usage_count < *usage_count))
224                 *usage_count = cell->usage_count;
225
226         platform_device_unregister(pdev);
227         return 0;
228 }
229
230 void mfd_remove_devices(struct device *parent)
231 {
232         atomic_t *cnts = NULL;
233
234         device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
235         kfree(cnts);
236 }
237 EXPORT_SYMBOL(mfd_remove_devices);
238
239 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
240 {
241         struct mfd_cell cell_entry;
242         struct device *dev;
243         struct platform_device *pdev;
244         int i;
245
246         /* fetch the parent cell's device (should already be registered!) */
247         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
248         if (!dev) {
249                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
250                 return -ENODEV;
251         }
252         pdev = to_platform_device(dev);
253         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
254
255         WARN_ON(!cell_entry.enable);
256
257         for (i = 0; i < n_clones; i++) {
258                 cell_entry.name = clones[i];
259                 /* don't give up if a single call fails; just report error */
260                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0,
261                                    NULL))
262                         dev_err(dev, "failed to create platform device '%s'\n",
263                                         clones[i]);
264         }
265
266         return 0;
267 }
268 EXPORT_SYMBOL(mfd_clone_cell);
269
270 MODULE_LICENSE("GPL");
271 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");