Add linux-next specific files for 20110831
[linux-2.6/next.git] / drivers / mfd / mfd-core.c
blob0f5922812bffdee8e3e892cab978052548d92114
1 /*
2 * drivers/mfd/mfd-core.c
4 * core MFD support
5 * Copyright (c) 2006 Ian Molton
6 * Copyright (c) 2007,2008 Dmitry Baryshkov
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.
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>
22 int mfd_cell_enable(struct platform_device *pdev)
24 const struct mfd_cell *cell = mfd_get_cell(pdev);
25 int err = 0;
27 /* only call enable hook if the cell wasn't previously enabled */
28 if (atomic_inc_return(cell->usage_count) == 1)
29 err = cell->enable(pdev);
31 /* if the enable hook failed, decrement counter to allow retries */
32 if (err)
33 atomic_dec(cell->usage_count);
35 return err;
37 EXPORT_SYMBOL(mfd_cell_enable);
39 int mfd_cell_disable(struct platform_device *pdev)
41 const struct mfd_cell *cell = mfd_get_cell(pdev);
42 int err = 0;
44 /* only disable if no other clients are using it */
45 if (atomic_dec_return(cell->usage_count) == 0)
46 err = cell->disable(pdev);
48 /* if the disable hook failed, increment to allow retries */
49 if (err)
50 atomic_inc(cell->usage_count);
52 /* sanity check; did someone call disable too many times? */
53 WARN_ON(atomic_read(cell->usage_count) < 0);
55 return err;
57 EXPORT_SYMBOL(mfd_cell_disable);
59 static int mfd_platform_add_cell(struct platform_device *pdev,
60 const struct mfd_cell *cell)
62 if (!cell)
63 return 0;
65 pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
66 if (!pdev->mfd_cell)
67 return -ENOMEM;
69 return 0;
72 static int mfd_add_device(struct device *parent, int id,
73 const struct mfd_cell *cell,
74 struct resource *mem_base,
75 int irq_base)
77 struct resource *res;
78 struct platform_device *pdev;
79 int ret = -ENOMEM;
80 int r;
82 pdev = platform_device_alloc(cell->name, id + cell->id);
83 if (!pdev)
84 goto fail_alloc;
86 res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
87 if (!res)
88 goto fail_device;
90 pdev->dev.parent = parent;
92 if (cell->pdata_size) {
93 ret = platform_device_add_data(pdev,
94 cell->platform_data, cell->pdata_size);
95 if (ret)
96 goto fail_res;
99 ret = mfd_platform_add_cell(pdev, cell);
100 if (ret)
101 goto fail_res;
103 for (r = 0; r < cell->num_resources; r++) {
104 res[r].name = cell->resources[r].name;
105 res[r].flags = cell->resources[r].flags;
107 /* Find out base to use */
108 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
109 res[r].parent = mem_base;
110 res[r].start = mem_base->start +
111 cell->resources[r].start;
112 res[r].end = mem_base->start +
113 cell->resources[r].end;
114 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
115 res[r].start = irq_base +
116 cell->resources[r].start;
117 res[r].end = irq_base +
118 cell->resources[r].end;
119 } else {
120 res[r].parent = cell->resources[r].parent;
121 res[r].start = cell->resources[r].start;
122 res[r].end = cell->resources[r].end;
125 if (!cell->ignore_resource_conflicts) {
126 ret = acpi_check_resource_conflict(res);
127 if (ret)
128 goto fail_res;
132 ret = platform_device_add_resources(pdev, res, cell->num_resources);
133 if (ret)
134 goto fail_res;
136 ret = platform_device_add(pdev);
137 if (ret)
138 goto fail_res;
140 if (cell->pm_runtime_no_callbacks)
141 pm_runtime_no_callbacks(&pdev->dev);
143 kfree(res);
145 return 0;
147 fail_res:
148 kfree(res);
149 fail_device:
150 platform_device_put(pdev);
151 fail_alloc:
152 return ret;
155 int mfd_add_devices(struct device *parent, int id,
156 struct mfd_cell *cells, int n_devs,
157 struct resource *mem_base,
158 int irq_base)
160 int i;
161 int ret = 0;
162 atomic_t *cnts;
164 /* initialize reference counting for all cells */
165 cnts = kcalloc(sizeof(*cnts), n_devs, GFP_KERNEL);
166 if (!cnts)
167 return -ENOMEM;
169 for (i = 0; i < n_devs; i++) {
170 atomic_set(&cnts[i], 0);
171 cells[i].usage_count = &cnts[i];
172 ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base);
173 if (ret)
174 break;
177 if (ret)
178 mfd_remove_devices(parent);
180 return ret;
182 EXPORT_SYMBOL(mfd_add_devices);
184 static int mfd_remove_devices_fn(struct device *dev, void *c)
186 struct platform_device *pdev = to_platform_device(dev);
187 const struct mfd_cell *cell = mfd_get_cell(pdev);
188 atomic_t **usage_count = c;
190 /* find the base address of usage_count pointers (for freeing) */
191 if (!*usage_count || (cell->usage_count < *usage_count))
192 *usage_count = cell->usage_count;
194 platform_device_unregister(pdev);
195 return 0;
198 void mfd_remove_devices(struct device *parent)
200 atomic_t *cnts = NULL;
202 device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
203 kfree(cnts);
205 EXPORT_SYMBOL(mfd_remove_devices);
207 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
209 struct mfd_cell cell_entry;
210 struct device *dev;
211 struct platform_device *pdev;
212 int i;
214 /* fetch the parent cell's device (should already be registered!) */
215 dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
216 if (!dev) {
217 printk(KERN_ERR "failed to find device for cell %s\n", cell);
218 return -ENODEV;
220 pdev = to_platform_device(dev);
221 memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
223 WARN_ON(!cell_entry.enable);
225 for (i = 0; i < n_clones; i++) {
226 cell_entry.name = clones[i];
227 /* don't give up if a single call fails; just report error */
228 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0))
229 dev_err(dev, "failed to create platform device '%s'\n",
230 clones[i]);
233 return 0;
235 EXPORT_SYMBOL(mfd_clone_cell);
237 MODULE_LICENSE("GPL");
238 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");