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/*
* drivers/mfd/mfd-core.c
*
* core MFD support
* Copyright (c) 2006 Ian Molton
* Copyright (c) 2007,2008 Dmitry Baryshkov
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/acpi.h>
#include <linux/mfd/core.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/module.h>
int mfd_cell_enable(struct platform_device *pdev)
{
const struct mfd_cell *cell = mfd_get_cell(pdev);
int err = 0;
/* only call enable hook if the cell wasn't previously enabled */
if (atomic_inc_return(cell->usage_count) == 1)
err = cell->enable(pdev);
/* if the enable hook failed, decrement counter to allow retries */
if (err)
atomic_dec(cell->usage_count);
return err;
}
EXPORT_SYMBOL(mfd_cell_enable);
int mfd_cell_disable(struct platform_device *pdev)
{
const struct mfd_cell *cell = mfd_get_cell(pdev);
int err = 0;
/* only disable if no other clients are using it */
if (atomic_dec_return(cell->usage_count) == 0)
err = cell->disable(pdev);
/* if the disable hook failed, increment to allow retries */
if (err)
atomic_inc(cell->usage_count);
/* sanity check; did someone call disable too many times? */
WARN_ON(atomic_read(cell->usage_count) < 0);
return err;
}
EXPORT_SYMBOL(mfd_cell_disable);
static int mfd_platform_add_cell(struct platform_device *pdev,
const struct mfd_cell *cell)
{
if (!cell)
return 0;
pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
if (!pdev->mfd_cell)
return -ENOMEM;
return 0;
}
static int mfd_add_device(struct device *parent, int id,
const struct mfd_cell *cell,
struct resource *mem_base,
int irq_base)
{
struct resource *res;
struct platform_device *pdev;
int ret = -ENOMEM;
int r;
pdev = platform_device_alloc(cell->name, id + cell->id);
if (!pdev)
goto fail_alloc;
res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
if (!res)
goto fail_device;
pdev->dev.parent = parent;
if (cell->pdata_size) {
ret = platform_device_add_data(pdev,
cell->platform_data, cell->pdata_size);
if (ret)
goto fail_res;
}
ret = mfd_platform_add_cell(pdev, cell);
if (ret)
goto fail_res;
for (r = 0; r < cell->num_resources; r++) {
res[r].name = cell->resources[r].name;
res[r].flags = cell->resources[r].flags;
/* Find out base to use */
if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
res[r].parent = mem_base;
res[r].start = mem_base->start +
cell->resources[r].start;
res[r].end = mem_base->start +
cell->resources[r].end;
} else if (cell->resources[r].flags & IORESOURCE_IRQ) {
res[r].start = irq_base +
cell->resources[r].start;
res[r].end = irq_base +
cell->resources[r].end;
} else {
res[r].parent = cell->resources[r].parent;
res[r].start = cell->resources[r].start;
res[r].end = cell->resources[r].end;
}
if (!cell->ignore_resource_conflicts) {
ret = acpi_check_resource_conflict(&res[r]);
if (ret)
goto fail_res;
}
}
ret = platform_device_add_resources(pdev, res, cell->num_resources);
if (ret)
goto fail_res;
ret = platform_device_add(pdev);
if (ret)
goto fail_res;
if (cell->pm_runtime_no_callbacks)
pm_runtime_no_callbacks(&pdev->dev);
kfree(res);
return 0;
fail_res:
kfree(res);
fail_device:
platform_device_put(pdev);
fail_alloc:
return ret;
}
int mfd_add_devices(struct device *parent, int id,
struct mfd_cell *cells, int n_devs,
struct resource *mem_base,
int irq_base)
{
int i;
int ret = 0;
atomic_t *cnts;
/* initialize reference counting for all cells */
cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
if (!cnts)
return -ENOMEM;
for (i = 0; i < n_devs; i++) {
atomic_set(&cnts[i], 0);
cells[i].usage_count = &cnts[i];
ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base);
if (ret)
break;
}
if (ret)
mfd_remove_devices(parent);
return ret;
}
EXPORT_SYMBOL(mfd_add_devices);
static int mfd_remove_devices_fn(struct device *dev, void *c)
{
struct platform_device *pdev = to_platform_device(dev);
const struct mfd_cell *cell = mfd_get_cell(pdev);
atomic_t **usage_count = c;
/* find the base address of usage_count pointers (for freeing) */
if (!*usage_count || (cell->usage_count < *usage_count))
*usage_count = cell->usage_count;
platform_device_unregister(pdev);
return 0;
}
void mfd_remove_devices(struct device *parent)
{
atomic_t *cnts = NULL;
device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
kfree(cnts);
}
EXPORT_SYMBOL(mfd_remove_devices);
int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
{
struct mfd_cell cell_entry;
struct device *dev;
struct platform_device *pdev;
int i;
/* fetch the parent cell's device (should already be registered!) */
dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
if (!dev) {
printk(KERN_ERR "failed to find device for cell %s\n", cell);
return -ENODEV;
}
pdev = to_platform_device(dev);
memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
WARN_ON(!cell_entry.enable);
for (i = 0; i < n_clones; i++) {
cell_entry.name = clones[i];
/* don't give up if a single call fails; just report error */
if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0))
dev_err(dev, "failed to create platform device '%s'\n",
clones[i]);
}
return 0;
}
EXPORT_SYMBOL(mfd_clone_cell);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");
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