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1// SPDX-License-Identifier: GPL-2.0+2/*3 * rcar-fcp.c -- R-Car Frame Compression Processor Driver4 *5 * Copyright (C) 2016 Renesas Electronics Corporation6 *7 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)8 */9 10#include <linux/device.h>11#include <linux/dma-mapping.h>12#include <linux/list.h>13#include <linux/module.h>14#include <linux/mod_devicetable.h>15#include <linux/mutex.h>16#include <linux/platform_device.h>17#include <linux/pm_runtime.h>18#include <linux/slab.h>19 20#include <media/rcar-fcp.h>21 22struct rcar_fcp_device {23 struct list_head list;24 struct device *dev;25};26 27static LIST_HEAD(fcp_devices);28static DEFINE_MUTEX(fcp_lock);29 30/* -----------------------------------------------------------------------------31 * Public API32 */33 34/**35 * rcar_fcp_get - Find and acquire a reference to an FCP instance36 * @np: Device node of the FCP instance37 *38 * Search the list of registered FCP instances for the instance corresponding to39 * the given device node.40 *41 * Return a pointer to the FCP instance, or an ERR_PTR if the instance can't be42 * found.43 */44struct rcar_fcp_device *rcar_fcp_get(const struct device_node *np)45{46 struct rcar_fcp_device *fcp;47 48 mutex_lock(&fcp_lock);49 50 list_for_each_entry(fcp, &fcp_devices, list) {51 if (fcp->dev->of_node != np)52 continue;53 54 get_device(fcp->dev);55 goto done;56 }57 58 fcp = ERR_PTR(-EPROBE_DEFER);59 60done:61 mutex_unlock(&fcp_lock);62 return fcp;63}64EXPORT_SYMBOL_GPL(rcar_fcp_get);65 66/**67 * rcar_fcp_put - Release a reference to an FCP instance68 * @fcp: The FCP instance69 *70 * Release the FCP instance acquired by a call to rcar_fcp_get().71 */72void rcar_fcp_put(struct rcar_fcp_device *fcp)73{74 if (fcp)75 put_device(fcp->dev);76}77EXPORT_SYMBOL_GPL(rcar_fcp_put);78 79struct device *rcar_fcp_get_device(struct rcar_fcp_device *fcp)80{81 return fcp->dev;82}83EXPORT_SYMBOL_GPL(rcar_fcp_get_device);84 85/**86 * rcar_fcp_enable - Enable an FCP87 * @fcp: The FCP instance88 *89 * Before any memory access through an FCP is performed by a module, the FCP90 * must be enabled by a call to this function. The enable calls are reference91 * counted, each successful call must be followed by one rcar_fcp_disable()92 * call when no more memory transfer can occur through the FCP.93 *94 * Return 0 on success or a negative error code if an error occurs. The enable95 * reference count isn't increased when this function returns an error.96 */97int rcar_fcp_enable(struct rcar_fcp_device *fcp)98{99 if (!fcp)100 return 0;101 102 return pm_runtime_resume_and_get(fcp->dev);103}104EXPORT_SYMBOL_GPL(rcar_fcp_enable);105 106/**107 * rcar_fcp_disable - Disable an FCP108 * @fcp: The FCP instance109 *110 * This function is the counterpart of rcar_fcp_enable(). As enable calls are111 * reference counted a disable call may not disable the FCP synchronously.112 */113void rcar_fcp_disable(struct rcar_fcp_device *fcp)114{115 if (fcp)116 pm_runtime_put(fcp->dev);117}118EXPORT_SYMBOL_GPL(rcar_fcp_disable);119 120/* -----------------------------------------------------------------------------121 * Platform Driver122 */123 124static int rcar_fcp_probe(struct platform_device *pdev)125{126 struct rcar_fcp_device *fcp;127 128 fcp = devm_kzalloc(&pdev->dev, sizeof(*fcp), GFP_KERNEL);129 if (fcp == NULL)130 return -ENOMEM;131 132 fcp->dev = &pdev->dev;133 134 dma_set_max_seg_size(fcp->dev, UINT_MAX);135 136 pm_runtime_enable(&pdev->dev);137 138 mutex_lock(&fcp_lock);139 list_add_tail(&fcp->list, &fcp_devices);140 mutex_unlock(&fcp_lock);141 142 platform_set_drvdata(pdev, fcp);143 144 return 0;145}146 147static void rcar_fcp_remove(struct platform_device *pdev)148{149 struct rcar_fcp_device *fcp = platform_get_drvdata(pdev);150 151 mutex_lock(&fcp_lock);152 list_del(&fcp->list);153 mutex_unlock(&fcp_lock);154 155 pm_runtime_disable(&pdev->dev);156}157 158static const struct of_device_id rcar_fcp_of_match[] = {159 { .compatible = "renesas,fcpf" },160 { .compatible = "renesas,fcpv" },161 { },162};163MODULE_DEVICE_TABLE(of, rcar_fcp_of_match);164 165static struct platform_driver rcar_fcp_platform_driver = {166 .probe = rcar_fcp_probe,167 .remove_new = rcar_fcp_remove,168 .driver = {169 .name = "rcar-fcp",170 .of_match_table = rcar_fcp_of_match,171 .suppress_bind_attrs = true,172 },173};174 175module_platform_driver(rcar_fcp_platform_driver);176 177MODULE_ALIAS("rcar-fcp");178MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");179MODULE_DESCRIPTION("Renesas FCP Driver");180MODULE_LICENSE("GPL");181