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// SPDX-License-Identifier: GPL-2.0
/*
* NVMEM layout bus handling
*
* Copyright (C) 2023 Bootlin
* Author: Miquel Raynal <miquel.raynal@bootlin.com
*/
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/nvmem-consumer.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include "internals.h"
#define to_nvmem_layout_driver(drv) \
(container_of((drv), struct nvmem_layout_driver, driver))
#define to_nvmem_layout_device(_dev) \
container_of((_dev), struct nvmem_layout, dev)
static int nvmem_layout_bus_match(struct device *dev, struct device_driver *drv)
{
return of_driver_match_device(dev, drv);
}
static int nvmem_layout_bus_probe(struct device *dev)
{
struct nvmem_layout_driver *drv = to_nvmem_layout_driver(dev->driver);
struct nvmem_layout *layout = to_nvmem_layout_device(dev);
if (!drv->probe || !drv->remove)
return -EINVAL;
return drv->probe(layout);
}
static void nvmem_layout_bus_remove(struct device *dev)
{
struct nvmem_layout_driver *drv = to_nvmem_layout_driver(dev->driver);
struct nvmem_layout *layout = to_nvmem_layout_device(dev);
return drv->remove(layout);
}
static const struct bus_type nvmem_layout_bus_type = {
.name = "nvmem-layout",
.match = nvmem_layout_bus_match,
.probe = nvmem_layout_bus_probe,
.remove = nvmem_layout_bus_remove,
};
int __nvmem_layout_driver_register(struct nvmem_layout_driver *drv,
struct module *owner)
{
drv->driver.bus = &nvmem_layout_bus_type;
drv->driver.owner = owner;
return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(__nvmem_layout_driver_register);
void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(nvmem_layout_driver_unregister);
static void nvmem_layout_release_device(struct device *dev)
{
struct nvmem_layout *layout = to_nvmem_layout_device(dev);
of_node_put(layout->dev.of_node);
kfree(layout);
}
static int nvmem_layout_create_device(struct nvmem_device *nvmem,
struct device_node *np)
{
struct nvmem_layout *layout;
struct device *dev;
int ret;
layout = kzalloc(sizeof(*layout), GFP_KERNEL);
if (!layout)
return -ENOMEM;
/* Create a bidirectional link */
layout->nvmem = nvmem;
nvmem->layout = layout;
/* Device model registration */
dev = &layout->dev;
device_initialize(dev);
dev->parent = &nvmem->dev;
dev->bus = &nvmem_layout_bus_type;
dev->release = nvmem_layout_release_device;
dev->coherent_dma_mask = DMA_BIT_MASK(32);
dev->dma_mask = &dev->coherent_dma_mask;
device_set_node(dev, of_fwnode_handle(of_node_get(np)));
of_device_make_bus_id(dev);
of_msi_configure(dev, dev->of_node);
ret = device_add(dev);
if (ret) {
put_device(dev);
return ret;
}
return 0;
}
static const struct of_device_id of_nvmem_layout_skip_table[] = {
{ .compatible = "fixed-layout", },
{}
};
static int nvmem_layout_bus_populate(struct nvmem_device *nvmem,
struct device_node *layout_dn)
{
int ret;
/* Make sure it has a compatible property */
if (!of_get_property(layout_dn, "compatible", NULL)) {
pr_debug("%s() - skipping %pOF, no compatible prop\n",
__func__, layout_dn);
return 0;
}
/* Fixed layouts are parsed manually somewhere else for now */
if (of_match_node(of_nvmem_layout_skip_table, layout_dn)) {
pr_debug("%s() - skipping %pOF node\n", __func__, layout_dn);
return 0;
}
if (of_node_check_flag(layout_dn, OF_POPULATED_BUS)) {
pr_debug("%s() - skipping %pOF, already populated\n",
__func__, layout_dn);
return 0;
}
/* NVMEM layout buses expect only a single device representing the layout */
ret = nvmem_layout_create_device(nvmem, layout_dn);
if (ret)
return ret;
of_node_set_flag(layout_dn, OF_POPULATED_BUS);
return 0;
}
struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)
{
return of_get_child_by_name(nvmem->dev.of_node, "nvmem-layout");
}
EXPORT_SYMBOL_GPL(of_nvmem_layout_get_container);
/*
* Returns the number of devices populated, 0 if the operation was not relevant
* for this nvmem device, an error code otherwise.
*/
int nvmem_populate_layout(struct nvmem_device *nvmem)
{
struct device_node *layout_dn;
int ret;
layout_dn = of_nvmem_layout_get_container(nvmem);
if (!layout_dn)
return 0;
/* Populate the layout device */
device_links_supplier_sync_state_pause();
ret = nvmem_layout_bus_populate(nvmem, layout_dn);
device_links_supplier_sync_state_resume();
of_node_put(layout_dn);
return ret;
}
void nvmem_destroy_layout(struct nvmem_device *nvmem)
{
struct device *dev;
if (!nvmem->layout)
return;
dev = &nvmem->layout->dev;
of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
device_unregister(dev);
}
int nvmem_layout_bus_register(void)
{
return bus_register(&nvmem_layout_bus_type);
}
void nvmem_layout_bus_unregister(void)
{
bus_unregister(&nvmem_layout_bus_type);
}
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