--- /dev/null
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/**
+ * rpivid-mem.c - character device access to the RPiVid decoder registers
+ *
+ * Based on bcm2835-gpiomem.c. Provides IO memory access to the decoder
+ * register blocks such that ffmpeg plugins can access the hardware.
+ *
+ * Jonathan Bell <jonathan@raspberrypi.org>
+ * Copyright (c) 2019, Raspberry Pi (Trading) Ltd.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions, and the following disclaimer,
+ * without modification.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The names of the above-listed copyright holders may not be used
+ * to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2, as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/cdev.h>
+#include <linux/pagemap.h>
+#include <linux/io.h>
+
+#define DRIVER_NAME "rpivid-mem"
+#define DEVICE_MINOR 0
+
+struct rpivid_mem_priv {
+ dev_t devid;
+ struct class *class;
+ struct cdev rpivid_mem_cdev;
+ unsigned long regs_phys;
+ unsigned long mem_window_len;
+ struct device *dev;
+ const char *name;
+};
+
+static int rpivid_mem_open(struct inode *inode, struct file *file)
+{
+ int dev = iminor(inode);
+ int ret = 0;
+ struct rpivid_mem_priv *priv;
+
+ if (dev != DEVICE_MINOR && dev != DEVICE_MINOR + 1)
+ ret = -ENXIO;
+
+ priv = container_of(inode->i_cdev, struct rpivid_mem_priv,
+ rpivid_mem_cdev);
+ if (!priv)
+ return -EINVAL;
+ file->private_data = priv;
+ return ret;
+}
+
+static int rpivid_mem_release(struct inode *inode, struct file *file)
+{
+ int dev = iminor(inode);
+ int ret = 0;
+
+ if (dev != DEVICE_MINOR && dev != DEVICE_MINOR + 1)
+ ret = -ENXIO;
+
+ return ret;
+}
+
+static const struct vm_operations_struct rpivid_mem_vm_ops = {
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+ .access = generic_access_phys
+#endif
+};
+
+static int rpivid_mem_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct rpivid_mem_priv *priv;
+ unsigned long pages;
+
+ priv = file->private_data;
+ pages = priv->regs_phys >> PAGE_SHIFT;
+ /*
+ * The address decode is far larger than the actual number of registers.
+ * Just map the whole lot in.
+ */
+ vma->vm_page_prot = phys_mem_access_prot(file, pages,
+ priv->mem_window_len,
+ vma->vm_page_prot);
+ vma->vm_ops = &rpivid_mem_vm_ops;
+ if (remap_pfn_range(vma, vma->vm_start,
+ pages,
+ priv->mem_window_len,
+ vma->vm_page_prot)) {
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+static const struct file_operations
+rpivid_mem_fops = {
+ .owner = THIS_MODULE,
+ .open = rpivid_mem_open,
+ .release = rpivid_mem_release,
+ .mmap = rpivid_mem_mmap,
+};
+
+static const struct of_device_id rpivid_mem_of_match[];
+static int rpivid_mem_probe(struct platform_device *pdev)
+{
+ int err;
+ const struct of_device_id *id;
+ struct device *dev = &pdev->dev;
+ struct resource *ioresource;
+ struct rpivid_mem_priv *priv;
+
+ /* Allocate buffers and instance data */
+
+ priv = kzalloc(sizeof(struct rpivid_mem_priv), GFP_KERNEL);
+
+ if (!priv) {
+ err = -ENOMEM;
+ goto failed_inst_alloc;
+ }
+ platform_set_drvdata(pdev, priv);
+
+ priv->dev = dev;
+ id = of_match_device(rpivid_mem_of_match, dev);
+ if (!id)
+ return -EINVAL;
+ priv->name = id->data;
+
+ ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (ioresource) {
+ priv->regs_phys = ioresource->start;
+ priv->mem_window_len = ioresource->end - ioresource->start;
+ } else {
+ dev_err(priv->dev, "failed to get IO resource");
+ err = -ENOENT;
+ goto failed_get_resource;
+ }
+
+ /* Create character device entries */
+
+ err = alloc_chrdev_region(&priv->devid,
+ DEVICE_MINOR, 2, priv->name);
+ if (err != 0) {
+ dev_err(priv->dev, "unable to allocate device number");
+ goto failed_alloc_chrdev;
+ }
+ cdev_init(&priv->rpivid_mem_cdev, &rpivid_mem_fops);
+ priv->rpivid_mem_cdev.owner = THIS_MODULE;
+ err = cdev_add(&priv->rpivid_mem_cdev, priv->devid, 2);
+ if (err != 0) {
+ dev_err(priv->dev, "unable to register device");
+ goto failed_cdev_add;
+ }
+
+ /* Create sysfs entries */
+
+ priv->class = class_create(THIS_MODULE, priv->name);
+ if (IS_ERR(priv->class)) {
+ err = PTR_ERR(priv->class);
+ goto failed_class_create;
+ }
+
+ dev = device_create(priv->class, NULL, priv->devid, NULL, priv->name);
+ if (IS_ERR(dev)) {
+ err = PTR_ERR(dev);
+ goto failed_device_create;
+ }
+
+ /* Legacy alias */
+ {
+ char *oldname = kstrdup(priv->name, GFP_KERNEL);
+
+ oldname[1] = 'a';
+ oldname[2] = 'r';
+ oldname[3] = 'g';
+ oldname[4] = 'o';
+ oldname[5] = 'n';
+ dev = device_create(priv->class, NULL, priv->devid + 1, NULL,
+ oldname + 1);
+ kfree(oldname);
+
+ if (IS_ERR(dev)) {
+ err = PTR_ERR(dev);
+ goto failed_legacy_device_create;
+ }
+ }
+
+ dev_info(priv->dev, "%s initialised: Registers at 0x%08lx length 0x%08lx",
+ priv->name, priv->regs_phys, priv->mem_window_len);
+
+ return 0;
+
+failed_legacy_device_create:
+ device_destroy(priv->class, priv->devid);
+failed_device_create:
+ class_destroy(priv->class);
+failed_class_create:
+ cdev_del(&priv->rpivid_mem_cdev);
+failed_cdev_add:
+ unregister_chrdev_region(priv->devid, 1);
+failed_alloc_chrdev:
+failed_get_resource:
+ kfree(priv);
+failed_inst_alloc:
+ dev_err(&pdev->dev, "could not load rpivid_mem");
+ return err;
+}
+
+static int rpivid_mem_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rpivid_mem_priv *priv = platform_get_drvdata(pdev);
+
+ device_destroy(priv->class, priv->devid + 1);
+ device_destroy(priv->class, priv->devid);
+ class_destroy(priv->class);
+ cdev_del(&priv->rpivid_mem_cdev);
+ unregister_chrdev_region(priv->devid, 1);
+ kfree(priv);
+
+ dev_info(dev, "%s driver removed - OK", priv->name);
+ return 0;
+}
+
+static const struct of_device_id rpivid_mem_of_match[] = {
+ {
+ .compatible = "raspberrypi,rpivid-hevc-decoder",
+ .data = "rpivid-hevcmem",
+ },
+ {
+ .compatible = "raspberrypi,rpivid-h264-decoder",
+ .data = "rpivid-h264mem",
+ },
+ {
+ .compatible = "raspberrypi,rpivid-vp9-decoder",
+ .data = "rpivid-vp9mem",
+ },
+ /* The "intc" is included as this block of hardware contains the
+ * "frame done" status flags.
+ */
+ {
+ .compatible = "raspberrypi,rpivid-local-intc",
+ .data = "rpivid-intcmem",
+ },
+ { /* sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, rpivid_mem_of_match);
+
+static struct platform_driver rpivid_mem_driver = {
+ .probe = rpivid_mem_probe,
+ .remove = rpivid_mem_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = rpivid_mem_of_match,
+ },
+};
+
+module_platform_driver(rpivid_mem_driver);
+
+MODULE_ALIAS("platform:rpivid-mem");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Driver for accessing RPiVid decoder registers from userspace");
+MODULE_AUTHOR("Jonathan Bell <jonathan@raspberrypi.org>");
projects / platform / kernel / linux-rpi.git / commitdiff