2 * drivers/mfd/mfd-core.c
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 static struct device_type mfd_dev_type = {
26 int mfd_cell_enable(struct platform_device *pdev)
28 const struct mfd_cell *cell = mfd_get_cell(pdev);
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);
35 /* if the enable hook failed, decrement counter to allow retries */
37 atomic_dec(cell->usage_count);
41 EXPORT_SYMBOL(mfd_cell_enable);
43 int mfd_cell_disable(struct platform_device *pdev)
45 const struct mfd_cell *cell = mfd_get_cell(pdev);
48 /* only disable if no other clients are using it */
49 if (atomic_dec_return(cell->usage_count) == 0)
50 err = cell->disable(pdev);
52 /* if the disable hook failed, increment to allow retries */
54 atomic_inc(cell->usage_count);
56 /* sanity check; did someone call disable too many times? */
57 WARN_ON(atomic_read(cell->usage_count) < 0);
61 EXPORT_SYMBOL(mfd_cell_disable);
63 static int mfd_platform_add_cell(struct platform_device *pdev,
64 const struct mfd_cell *cell)
69 pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
76 static int mfd_add_device(struct device *parent, int id,
77 const struct mfd_cell *cell,
78 struct resource *mem_base,
82 struct platform_device *pdev;
86 pdev = platform_device_alloc(cell->name, id + cell->id);
90 res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
94 pdev->dev.parent = parent;
95 pdev->dev.type = &mfd_dev_type;
97 if (cell->pdata_size) {
98 ret = platform_device_add_data(pdev,
99 cell->platform_data, cell->pdata_size);
104 ret = mfd_platform_add_cell(pdev, cell);
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;
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;
125 res[r].parent = cell->resources[r].parent;
126 res[r].start = cell->resources[r].start;
127 res[r].end = cell->resources[r].end;
130 if (!cell->ignore_resource_conflicts) {
131 ret = acpi_check_resource_conflict(&res[r]);
137 ret = platform_device_add_resources(pdev, res, cell->num_resources);
141 ret = platform_device_add(pdev);
145 if (cell->pm_runtime_no_callbacks)
146 pm_runtime_no_callbacks(&pdev->dev);
155 platform_device_put(pdev);
160 int mfd_add_devices(struct device *parent, int id,
161 struct mfd_cell *cells, int n_devs,
162 struct resource *mem_base,
169 /* initialize reference counting for all cells */
170 cnts = kcalloc(sizeof(*cnts), n_devs, GFP_KERNEL);
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);
183 mfd_remove_devices(parent);
187 EXPORT_SYMBOL(mfd_add_devices);
189 static int mfd_remove_devices_fn(struct device *dev, void *c)
191 struct platform_device *pdev;
192 const struct mfd_cell *cell;
193 atomic_t **usage_count = c;
195 if (dev->type != &mfd_dev_type)
198 pdev = to_platform_device(dev);
199 cell = mfd_get_cell(pdev);
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;
205 platform_device_unregister(pdev);
209 void mfd_remove_devices(struct device *parent)
211 atomic_t *cnts = NULL;
213 device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
216 EXPORT_SYMBOL(mfd_remove_devices);
218 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
220 struct mfd_cell cell_entry;
222 struct platform_device *pdev;
225 /* fetch the parent cell's device (should already be registered!) */
226 dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
228 printk(KERN_ERR "failed to find device for cell %s\n", cell);
231 pdev = to_platform_device(dev);
232 memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
234 WARN_ON(!cell_entry.enable);
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",
246 EXPORT_SYMBOL(mfd_clone_cell);
248 MODULE_LICENSE("GPL");
249 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");