linux/drivers/mfd/mfd-core.c
Bartosz Golaszewski 1946f9967c mfd: mfd-core: Document mfd_add_devices()
Add a kernel doc for mfd_add_devices().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2019-05-08 12:06:02 +01:00

423 lines
10 KiB
C

/*
* 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/property.h>
#include <linux/mfd/core.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>
static struct device_type mfd_dev_type = {
.name = "mfd_device",
};
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,
atomic_t *usage_count)
{
if (!cell)
return 0;
pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
if (!pdev->mfd_cell)
return -ENOMEM;
pdev->mfd_cell->usage_count = usage_count;
return 0;
}
#if IS_ENABLED(CONFIG_ACPI)
static void mfd_acpi_add_device(const struct mfd_cell *cell,
struct platform_device *pdev)
{
const struct mfd_cell_acpi_match *match = cell->acpi_match;
struct acpi_device *parent, *child;
struct acpi_device *adev;
parent = ACPI_COMPANION(pdev->dev.parent);
if (!parent)
return;
/*
* MFD child device gets its ACPI handle either from the ACPI device
* directly under the parent that matches the either _HID or _CID, or
* _ADR or it will use the parent handle if is no ID is given.
*
* Note that use of _ADR is a grey area in the ACPI specification,
* though Intel Galileo Gen2 is using it to distinguish the children
* devices.
*/
adev = parent;
if (match) {
if (match->pnpid) {
struct acpi_device_id ids[2] = {};
strlcpy(ids[0].id, match->pnpid, sizeof(ids[0].id));
list_for_each_entry(child, &parent->children, node) {
if (!acpi_match_device_ids(child, ids)) {
adev = child;
break;
}
}
} else {
unsigned long long adr;
acpi_status status;
list_for_each_entry(child, &parent->children, node) {
status = acpi_evaluate_integer(child->handle,
"_ADR", NULL,
&adr);
if (ACPI_SUCCESS(status) && match->adr == adr) {
adev = child;
break;
}
}
}
}
ACPI_COMPANION_SET(&pdev->dev, adev);
}
#else
static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
struct platform_device *pdev)
{
}
#endif
static int mfd_add_device(struct device *parent, int id,
const struct mfd_cell *cell, atomic_t *usage_count,
struct resource *mem_base,
int irq_base, struct irq_domain *domain)
{
struct resource *res;
struct platform_device *pdev;
struct device_node *np = NULL;
int ret = -ENOMEM;
int platform_id;
int r;
if (id == PLATFORM_DEVID_AUTO)
platform_id = id;
else
platform_id = id + cell->id;
pdev = platform_device_alloc(cell->name, platform_id);
if (!pdev)
goto fail_alloc;
res = kcalloc(cell->num_resources, sizeof(*res), GFP_KERNEL);
if (!res)
goto fail_device;
pdev->dev.parent = parent;
pdev->dev.type = &mfd_dev_type;
pdev->dev.dma_mask = parent->dma_mask;
pdev->dev.dma_parms = parent->dma_parms;
pdev->dev.coherent_dma_mask = parent->coherent_dma_mask;
ret = regulator_bulk_register_supply_alias(
&pdev->dev, cell->parent_supplies,
parent, cell->parent_supplies,
cell->num_parent_supplies);
if (ret < 0)
goto fail_res;
if (parent->of_node && cell->of_compatible) {
for_each_child_of_node(parent->of_node, np) {
if (of_device_is_compatible(np, cell->of_compatible)) {
pdev->dev.of_node = np;
break;
}
}
}
mfd_acpi_add_device(cell, pdev);
if (cell->pdata_size) {
ret = platform_device_add_data(pdev,
cell->platform_data, cell->pdata_size);
if (ret)
goto fail_alias;
}
if (cell->properties) {
ret = platform_device_add_properties(pdev, cell->properties);
if (ret)
goto fail_alias;
}
ret = mfd_platform_add_cell(pdev, cell, usage_count);
if (ret)
goto fail_alias;
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) {
if (domain) {
/* Unable to create mappings for IRQ ranges. */
WARN_ON(cell->resources[r].start !=
cell->resources[r].end);
res[r].start = res[r].end = irq_create_mapping(
domain, cell->resources[r].start);
} else {
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) {
if (has_acpi_companion(&pdev->dev)) {
ret = acpi_check_resource_conflict(&res[r]);
if (ret)
goto fail_alias;
}
}
}
ret = platform_device_add_resources(pdev, res, cell->num_resources);
if (ret)
goto fail_alias;
ret = platform_device_add(pdev);
if (ret)
goto fail_alias;
if (cell->pm_runtime_no_callbacks)
pm_runtime_no_callbacks(&pdev->dev);
kfree(res);
return 0;
fail_alias:
regulator_bulk_unregister_supply_alias(&pdev->dev,
cell->parent_supplies,
cell->num_parent_supplies);
fail_res:
kfree(res);
fail_device:
platform_device_put(pdev);
fail_alloc:
return ret;
}
/**
* mfd_add_devices - register child devices
*
* @parent: Pointer to parent device.
* @id: Can be PLATFORM_DEVID_AUTO to let the Platform API take care
* of device numbering, or will be added to a device's cell_id.
* @cells: Array of (struct mfd_cell)s describing child devices.
* @n_devs: Number of child devices to register.
* @mem_base: Parent register range resource for child devices.
* @irq_base: Base of the range of virtual interrupt numbers allocated for
* this MFD device. Unused if @domain is specified.
* @domain: Interrupt domain to create mappings for hardware interrupts.
*/
int mfd_add_devices(struct device *parent, int id,
const struct mfd_cell *cells, int n_devs,
struct resource *mem_base,
int irq_base, struct irq_domain *domain)
{
int i;
int ret;
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);
ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,
irq_base, domain);
if (ret)
goto fail;
}
return 0;
fail:
if (i)
mfd_remove_devices(parent);
else
kfree(cnts);
return ret;
}
EXPORT_SYMBOL(mfd_add_devices);
static int mfd_remove_devices_fn(struct device *dev, void *c)
{
struct platform_device *pdev;
const struct mfd_cell *cell;
atomic_t **usage_count = c;
if (dev->type != &mfd_dev_type)
return 0;
pdev = to_platform_device(dev);
cell = mfd_get_cell(pdev);
regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,
cell->num_parent_supplies);
/* 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_reverse(parent, &cnts, mfd_remove_devices_fn);
kfree(cnts);
}
EXPORT_SYMBOL(mfd_remove_devices);
static void devm_mfd_dev_release(struct device *dev, void *res)
{
mfd_remove_devices(dev);
}
/**
* devm_mfd_add_devices - Resource managed version of mfd_add_devices()
*
* Returns 0 on success or an appropriate negative error number on failure.
* All child-devices of the MFD will automatically be removed when it gets
* unbinded.
*/
int devm_mfd_add_devices(struct device *dev, int id,
const struct mfd_cell *cells, int n_devs,
struct resource *mem_base,
int irq_base, struct irq_domain *domain)
{
struct device **ptr;
int ret;
ptr = devres_alloc(devm_mfd_dev_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return -ENOMEM;
ret = mfd_add_devices(dev, id, cells, n_devs, mem_base,
irq_base, domain);
if (ret < 0) {
devres_free(ptr);
return ret;
}
*ptr = dev;
devres_add(dev, ptr);
return ret;
}
EXPORT_SYMBOL(devm_mfd_add_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,
cell_entry.usage_count, NULL, 0, NULL))
dev_err(dev, "failed to create platform device '%s'\n",
clones[i]);
}
put_device(dev);
return 0;
}
EXPORT_SYMBOL(mfd_clone_cell);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");