pktgen: correctly handle failures when adding a device
[linux-2.6.git] / 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
22 static struct device_type mfd_dev_type = {
23         .name   = "mfd_device",
24 };
25
26 int mfd_cell_enable(struct platform_device *pdev)
27 {
28         const struct mfd_cell *cell = mfd_get_cell(pdev);
29         int err = 0;
30
31         /* only call enable hook if the cell wasn't previously enabled */
32         if (atomic_inc_return(cell->usage_count) == 1)
33                 err = cell->enable(pdev);
34
35         /* if the enable hook failed, decrement counter to allow retries */
36         if (err)
37                 atomic_dec(cell->usage_count);
38
39         return err;
40 }
41 EXPORT_SYMBOL(mfd_cell_enable);
42
43 int mfd_cell_disable(struct platform_device *pdev)
44 {
45         const struct mfd_cell *cell = mfd_get_cell(pdev);
46         int err = 0;
47
48         /* only disable if no other clients are using it */
49         if (atomic_dec_return(cell->usage_count) == 0)
50                 err = cell->disable(pdev);
51
52         /* if the disable hook failed, increment to allow retries */
53         if (err)
54                 atomic_inc(cell->usage_count);
55
56         /* sanity check; did someone call disable too many times? */
57         WARN_ON(atomic_read(cell->usage_count) < 0);
58
59         return err;
60 }
61 EXPORT_SYMBOL(mfd_cell_disable);
62
63 static int mfd_platform_add_cell(struct platform_device *pdev,
64                                  const struct mfd_cell *cell)
65 {
66         if (!cell)
67                 return 0;
68
69         pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
70         if (!pdev->mfd_cell)
71                 return -ENOMEM;
72
73         return 0;
74 }
75
76 static int mfd_add_device(struct device *parent, int id,
77                           const struct mfd_cell *cell,
78                           struct resource *mem_base,
79                           int irq_base)
80 {
81         struct resource *res;
82         struct platform_device *pdev;
83         int ret = -ENOMEM;
84         int r;
85
86         pdev = platform_device_alloc(cell->name, id + cell->id);
87         if (!pdev)
88                 goto fail_alloc;
89
90         res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
91         if (!res)
92                 goto fail_device;
93
94         pdev->dev.parent = parent;
95         pdev->dev.type = &mfd_dev_type;
96
97         if (cell->pdata_size) {
98                 ret = platform_device_add_data(pdev,
99                                         cell->platform_data, cell->pdata_size);
100                 if (ret)
101                         goto fail_res;
102         }
103
104         ret = mfd_platform_add_cell(pdev, cell);
105         if (ret)
106                 goto fail_res;
107
108         for (r = 0; r < cell->num_resources; r++) {
109                 res[r].name = cell->resources[r].name;
110                 res[r].flags = cell->resources[r].flags;
111
112                 /* Find out base to use */
113                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
114                         res[r].parent = mem_base;
115                         res[r].start = mem_base->start +
116                                 cell->resources[r].start;
117                         res[r].end = mem_base->start +
118                                 cell->resources[r].end;
119                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
120                         res[r].start = irq_base +
121                                 cell->resources[r].start;
122                         res[r].end   = irq_base +
123                                 cell->resources[r].end;
124                 } else {
125                         res[r].parent = cell->resources[r].parent;
126                         res[r].start = cell->resources[r].start;
127                         res[r].end   = cell->resources[r].end;
128                 }
129
130                 if (!cell->ignore_resource_conflicts) {
131                         ret = acpi_check_resource_conflict(&res[r]);
132                         if (ret)
133                                 goto fail_res;
134                 }
135         }
136
137         ret = platform_device_add_resources(pdev, res, cell->num_resources);
138         if (ret)
139                 goto fail_res;
140
141         ret = platform_device_add(pdev);
142         if (ret)
143                 goto fail_res;
144
145         if (cell->pm_runtime_no_callbacks)
146                 pm_runtime_no_callbacks(&pdev->dev);
147
148         kfree(res);
149
150         return 0;
151
152 fail_res:
153         kfree(res);
154 fail_device:
155         platform_device_put(pdev);
156 fail_alloc:
157         return ret;
158 }
159
160 int mfd_add_devices(struct device *parent, int id,
161                     struct mfd_cell *cells, int n_devs,
162                     struct resource *mem_base,
163                     int irq_base)
164 {
165         int i;
166         int ret = 0;
167         atomic_t *cnts;
168
169         /* initialize reference counting for all cells */
170         cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
171         if (!cnts)
172                 return -ENOMEM;
173
174         for (i = 0; i < n_devs; i++) {
175                 atomic_set(&cnts[i], 0);
176                 cells[i].usage_count = &cnts[i];
177                 ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base);
178                 if (ret)
179                         break;
180         }
181
182         if (ret)
183                 mfd_remove_devices(parent);
184
185         return ret;
186 }
187 EXPORT_SYMBOL(mfd_add_devices);
188
189 static int mfd_remove_devices_fn(struct device *dev, void *c)
190 {
191         struct platform_device *pdev;
192         const struct mfd_cell *cell;
193         atomic_t **usage_count = c;
194
195         if (dev->type != &mfd_dev_type)
196                 return 0;
197
198         pdev = to_platform_device(dev);
199         cell = mfd_get_cell(pdev);
200
201         /* find the base address of usage_count pointers (for freeing) */
202         if (!*usage_count || (cell->usage_count < *usage_count))
203                 *usage_count = cell->usage_count;
204
205         platform_device_unregister(pdev);
206         return 0;
207 }
208
209 void mfd_remove_devices(struct device *parent)
210 {
211         atomic_t *cnts = NULL;
212
213         device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
214         kfree(cnts);
215 }
216 EXPORT_SYMBOL(mfd_remove_devices);
217
218 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
219 {
220         struct mfd_cell cell_entry;
221         struct device *dev;
222         struct platform_device *pdev;
223         int i;
224
225         /* fetch the parent cell's device (should already be registered!) */
226         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
227         if (!dev) {
228                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
229                 return -ENODEV;
230         }
231         pdev = to_platform_device(dev);
232         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
233
234         WARN_ON(!cell_entry.enable);
235
236         for (i = 0; i < n_clones; i++) {
237                 cell_entry.name = clones[i];
238                 /* don't give up if a single call fails; just report error */
239                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0))
240                         dev_err(dev, "failed to create platform device '%s'\n",
241                                         clones[i]);
242         }
243
244         return 0;
245 }
246 EXPORT_SYMBOL(mfd_clone_cell);
247
248 MODULE_LICENSE("GPL");
249 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");