config: tegra3: enable /dev mount with ACL
[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
21 int mfd_cell_enable(struct platform_device *pdev)
22 {
23         const struct mfd_cell *cell = mfd_get_cell(pdev);
24         int err = 0;
25
26         /* only call enable hook if the cell wasn't previously enabled */
27         if (atomic_inc_return(cell->usage_count) == 1)
28                 err = cell->enable(pdev);
29
30         /* if the enable hook failed, decrement counter to allow retries */
31         if (err)
32                 atomic_dec(cell->usage_count);
33
34         return err;
35 }
36 EXPORT_SYMBOL(mfd_cell_enable);
37
38 int mfd_cell_disable(struct platform_device *pdev)
39 {
40         const struct mfd_cell *cell = mfd_get_cell(pdev);
41         int err = 0;
42
43         /* only disable if no other clients are using it */
44         if (atomic_dec_return(cell->usage_count) == 0)
45                 err = cell->disable(pdev);
46
47         /* if the disable hook failed, increment to allow retries */
48         if (err)
49                 atomic_inc(cell->usage_count);
50
51         /* sanity check; did someone call disable too many times? */
52         WARN_ON(atomic_read(cell->usage_count) < 0);
53
54         return err;
55 }
56 EXPORT_SYMBOL(mfd_cell_disable);
57
58 static int mfd_platform_add_cell(struct platform_device *pdev,
59                                  const struct mfd_cell *cell)
60 {
61         if (!cell)
62                 return 0;
63
64         pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
65         if (!pdev->mfd_cell)
66                 return -ENOMEM;
67
68         return 0;
69 }
70
71 static int mfd_add_device(struct device *parent, int id,
72                           const struct mfd_cell *cell,
73                           struct resource *mem_base,
74                           int irq_base)
75 {
76         struct resource *res;
77         struct platform_device *pdev;
78         int ret = -ENOMEM;
79         int r;
80
81         pdev = platform_device_alloc(cell->name, id + cell->id);
82         if (!pdev)
83                 goto fail_alloc;
84
85         res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
86         if (!res)
87                 goto fail_device;
88
89         pdev->dev.parent = parent;
90
91         if (cell->pdata_size) {
92                 ret = platform_device_add_data(pdev,
93                                         cell->platform_data, cell->pdata_size);
94                 if (ret)
95                         goto fail_res;
96         }
97
98         ret = mfd_platform_add_cell(pdev, cell);
99         if (ret)
100                 goto fail_res;
101
102         for (r = 0; r < cell->num_resources; r++) {
103                 res[r].name = cell->resources[r].name;
104                 res[r].flags = cell->resources[r].flags;
105
106                 /* Find out base to use */
107                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
108                         res[r].parent = mem_base;
109                         res[r].start = mem_base->start +
110                                 cell->resources[r].start;
111                         res[r].end = mem_base->start +
112                                 cell->resources[r].end;
113                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
114                         res[r].start = irq_base +
115                                 cell->resources[r].start;
116                         res[r].end   = irq_base +
117                                 cell->resources[r].end;
118                 } else {
119                         res[r].parent = cell->resources[r].parent;
120                         res[r].start = cell->resources[r].start;
121                         res[r].end   = cell->resources[r].end;
122                 }
123
124                 if (!cell->ignore_resource_conflicts) {
125                         ret = acpi_check_resource_conflict(res);
126                         if (ret)
127                                 goto fail_res;
128                 }
129         }
130
131         ret = platform_device_add_resources(pdev, res, cell->num_resources);
132         if (ret)
133                 goto fail_res;
134
135         ret = platform_device_add(pdev);
136         if (ret)
137                 goto fail_res;
138
139         if (cell->pm_runtime_no_callbacks)
140                 pm_runtime_no_callbacks(&pdev->dev);
141
142         kfree(res);
143
144         return 0;
145
146 fail_res:
147         kfree(res);
148 fail_device:
149         platform_device_put(pdev);
150 fail_alloc:
151         return ret;
152 }
153
154 int mfd_add_devices(struct device *parent, int id,
155                     struct mfd_cell *cells, int n_devs,
156                     struct resource *mem_base,
157                     int irq_base)
158 {
159         int i;
160         int ret = 0;
161         atomic_t *cnts;
162
163         /* initialize reference counting for all cells */
164         cnts = kcalloc(sizeof(*cnts), n_devs, GFP_KERNEL);
165         if (!cnts)
166                 return -ENOMEM;
167
168         for (i = 0; i < n_devs; i++) {
169                 atomic_set(&cnts[i], 0);
170                 cells[i].usage_count = &cnts[i];
171                 ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base);
172                 if (ret)
173                         break;
174         }
175
176         if (ret)
177                 mfd_remove_devices(parent);
178
179         return ret;
180 }
181 EXPORT_SYMBOL(mfd_add_devices);
182
183 static int mfd_remove_devices_fn(struct device *dev, void *c)
184 {
185         struct platform_device *pdev = to_platform_device(dev);
186         const struct mfd_cell *cell = mfd_get_cell(pdev);
187         atomic_t **usage_count = c;
188
189         /* find the base address of usage_count pointers (for freeing) */
190         if (!*usage_count || (cell->usage_count < *usage_count))
191                 *usage_count = cell->usage_count;
192
193         platform_device_unregister(pdev);
194         return 0;
195 }
196
197 void mfd_remove_devices(struct device *parent)
198 {
199         atomic_t *cnts = NULL;
200
201         device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
202         kfree(cnts);
203 }
204 EXPORT_SYMBOL(mfd_remove_devices);
205
206 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
207 {
208         struct mfd_cell cell_entry;
209         struct device *dev;
210         struct platform_device *pdev;
211         int i;
212
213         /* fetch the parent cell's device (should already be registered!) */
214         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
215         if (!dev) {
216                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
217                 return -ENODEV;
218         }
219         pdev = to_platform_device(dev);
220         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
221
222         WARN_ON(!cell_entry.enable);
223
224         for (i = 0; i < n_clones; i++) {
225                 cell_entry.name = clones[i];
226                 /* don't give up if a single call fails; just report error */
227                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0))
228                         dev_err(dev, "failed to create platform device '%s'\n",
229                                         clones[i]);
230         }
231
232         return 0;
233 }
234 EXPORT_SYMBOL(mfd_clone_cell);
235
236 MODULE_LICENSE("GPL");
237 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");