linux/drivers/media/platform/renesas/rcar-fcp.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * rcar-fcp.c  --  R-Car Frame Compression Processor Driver
 *
 * Copyright (C) 2016 Renesas Electronics Corporation
 *
 * Contact: Laurent Pinchart ([email protected])
 */

#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

#include <media/rcar-fcp.h>

struct rcar_fcp_device { … };

static LIST_HEAD(fcp_devices);
static DEFINE_MUTEX(fcp_lock);

/* -----------------------------------------------------------------------------
 * Public API
 */

/**
 * rcar_fcp_get - Find and acquire a reference to an FCP instance
 * @np: Device node of the FCP instance
 *
 * Search the list of registered FCP instances for the instance corresponding to
 * the given device node.
 *
 * Return a pointer to the FCP instance, or an ERR_PTR if the instance can't be
 * found.
 */
struct rcar_fcp_device *rcar_fcp_get(const struct device_node *np)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * rcar_fcp_put - Release a reference to an FCP instance
 * @fcp: The FCP instance
 *
 * Release the FCP instance acquired by a call to rcar_fcp_get().
 */
void rcar_fcp_put(struct rcar_fcp_device *fcp)
{ … }
EXPORT_SYMBOL_GPL(…);

struct device *rcar_fcp_get_device(struct rcar_fcp_device *fcp)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * rcar_fcp_enable - Enable an FCP
 * @fcp: The FCP instance
 *
 * Before any memory access through an FCP is performed by a module, the FCP
 * must be enabled by a call to this function. The enable calls are reference
 * counted, each successful call must be followed by one rcar_fcp_disable()
 * call when no more memory transfer can occur through the FCP.
 *
 * Return 0 on success or a negative error code if an error occurs. The enable
 * reference count isn't increased when this function returns an error.
 */
int rcar_fcp_enable(struct rcar_fcp_device *fcp)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * rcar_fcp_disable - Disable an FCP
 * @fcp: The FCP instance
 *
 * This function is the counterpart of rcar_fcp_enable(). As enable calls are
 * reference counted a disable call may not disable the FCP synchronously.
 */
void rcar_fcp_disable(struct rcar_fcp_device *fcp)
{ … }
EXPORT_SYMBOL_GPL(…);

/* -----------------------------------------------------------------------------
 * Platform Driver
 */

static int rcar_fcp_probe(struct platform_device *pdev)
{ … }

static void rcar_fcp_remove(struct platform_device *pdev)
{ … }

static const struct of_device_id rcar_fcp_of_match[] = …;
MODULE_DEVICE_TABLE(of, rcar_fcp_of_match);

static struct platform_driver rcar_fcp_platform_driver = …;

module_platform_driver(…) …;

MODULE_ALIAS(…) …;
MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;