--- /dev/null
+From 0be0d6439128366a8d2ac0afaf88f19209171e51 Mon Sep 17 00:00:00 2001
+From: Jonathan Bell <jonathan@raspberrypi.org>
+Date: Thu, 9 May 2019 14:30:37 +0100
+Subject: [PATCH] drivers: char: add chardev for mmap'ing Argon control
+ registers
+
+Based on the gpiomem driver, allow mapping of the decoder register
+spaces such that userspace can access control/status registers.
+This driver is intended for use with a custom ffmpeg backend accelerator
+prior to a v4l2 driver being written.
+
+Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>
+---
+ drivers/char/broadcom/Kconfig | 8 +
+ drivers/char/broadcom/Makefile | 1 +
+ drivers/char/broadcom/argon-mem.c | 277 ++++++++++++++++++++++++++++++
+ 3 files changed, 286 insertions(+)
+ create mode 100644 drivers/char/broadcom/argon-mem.c
+
+--- a/drivers/char/broadcom/Kconfig
++++ b/drivers/char/broadcom/Kconfig
+@@ -49,3 +49,11 @@ config BCM2835_SMI_DEV
+ This driver provides a character device interface (ioctl + read/write) to
+ Broadcom's Secondary Memory interface. The low-level functionality is provided
+ by the SMI driver itself.
++
++config ARGON_MEM
++ tristate "Character device driver for the Argon decoder hardware"
++ default n
++ help
++ This driver provides a character device interface for memory-map operations
++ so userspace tools can access the control and status registers of the Argon
++ video decoder hardware.
+--- a/drivers/char/broadcom/Makefile
++++ b/drivers/char/broadcom/Makefile
+@@ -4,3 +4,4 @@ obj-$(CONFIG_BCM_VC_SM) += vc_sm
+
+ obj-$(CONFIG_BCM2835_DEVGPIOMEM)+= bcm2835-gpiomem.o
+ obj-$(CONFIG_BCM2835_SMI_DEV) += bcm2835_smi_dev.o
++obj-$(CONFIG_ARGON_MEM) += argon-mem.o
+--- /dev/null
++++ b/drivers/char/broadcom/argon-mem.c
+@@ -0,0 +1,277 @@
++/**
++ * argon-mem.c - character device access to the Argon 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 "argon-mem"
++#define DEVICE_MINOR 0
++
++struct argon_mem_priv {
++ dev_t devid;
++ struct class *class;
++ struct cdev argon_mem_cdev;
++ unsigned long regs_phys;
++ unsigned long mem_window_len;
++ struct device *dev;
++ const char *name;
++};
++
++static int argon_mem_open(struct inode *inode, struct file *file)
++{
++ int dev = iminor(inode);
++ int ret = 0;
++ struct argon_mem_priv *priv;
++ if (dev != DEVICE_MINOR)
++ ret = -ENXIO;
++
++ priv = container_of(inode->i_cdev, struct argon_mem_priv,
++ argon_mem_cdev);
++ if (!priv)
++ return -EINVAL;
++ file->private_data = priv;
++ return ret;
++}
++
++static int argon_mem_release(struct inode *inode, struct file *file)
++{
++ int dev = iminor(inode);
++ int ret = 0;
++
++ if (dev != DEVICE_MINOR)
++ ret = -ENXIO;
++
++ return ret;
++}
++
++static const struct vm_operations_struct argon_mem_vm_ops = {
++#ifdef CONFIG_HAVE_IOREMAP_PROT
++ .access = generic_access_phys
++#endif
++};
++
++static int argon_mem_mmap(struct file *file, struct vm_area_struct *vma)
++{
++ struct argon_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 = &argon_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
++argon_mem_fops = {
++ .owner = THIS_MODULE,
++ .open = argon_mem_open,
++ .release = argon_mem_release,
++ .mmap = argon_mem_mmap,
++};
++
++static const struct of_device_id argon_mem_of_match[];
++static int argon_mem_probe(struct platform_device *pdev)
++{
++ int err;
++ void *ptr_err;
++ const struct of_device_id *id;
++ struct device *dev = &pdev->dev;
++ struct device *argon_mem_dev;
++ struct resource *ioresource;
++ struct argon_mem_priv *priv;
++
++
++ /* Allocate buffers and instance data */
++
++ priv = kzalloc(sizeof(struct argon_mem_priv), GFP_KERNEL);
++
++ if (!priv) {
++ err = -ENOMEM;
++ goto failed_inst_alloc;
++ }
++ platform_set_drvdata(pdev, priv);
++
++ priv->dev = dev;
++ id = of_match_device(argon_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, 1, priv->name);
++ if (err != 0) {
++ dev_err(priv->dev, "unable to allocate device number");
++ goto failed_alloc_chrdev;
++ }
++ cdev_init(&priv->argon_mem_cdev, &argon_mem_fops);
++ priv->argon_mem_cdev.owner = THIS_MODULE;
++ err = cdev_add(&priv->argon_mem_cdev, priv->devid, 1);
++ 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);
++ ptr_err = priv->class;
++ if (IS_ERR(ptr_err))
++ goto failed_class_create;
++
++ argon_mem_dev = device_create(priv->class, NULL,
++ priv->devid, NULL,
++ priv->name);
++ ptr_err = argon_mem_dev;
++ if (IS_ERR(ptr_err))
++ goto failed_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_device_create:
++ class_destroy(priv->class);
++failed_class_create:
++ cdev_del(&priv->argon_mem_cdev);
++ err = PTR_ERR(ptr_err);
++failed_cdev_add:
++ unregister_chrdev_region(priv->devid, 1);
++failed_alloc_chrdev:
++failed_get_resource:
++ kfree(priv);
++failed_inst_alloc:
++ dev_err(priv->dev, "could not load argon_mem");
++ return err;
++}
++
++static int argon_mem_remove(struct platform_device *pdev)
++{
++ struct device *dev = &pdev->dev;
++ struct argon_mem_priv *priv = platform_get_drvdata(pdev);
++
++ device_destroy(priv->class, priv->devid);
++ class_destroy(priv->class);
++ cdev_del(&priv->argon_mem_cdev);
++ unregister_chrdev_region(priv->devid, 1);
++ kfree(priv);
++
++ dev_info(dev, "%s driver removed - OK", priv->name);
++ return 0;
++}
++
++static const char argon_hevc_name[] = "argon-hevcmem";
++static const char argon_h264_name[] = "argon-h264mem";
++static const char argon_vp9_name[] = "argon-vp9mem";
++static const char argon_intc_name[] = "argon-intcmem";
++
++static const struct of_device_id argon_mem_of_match[] = {
++ {
++ .compatible = "raspberrypi,argon-hevc-decoder",
++ .data = &argon_hevc_name,
++ },
++ {
++ .compatible = "raspberrypi,argon-h264-decoder",
++ .data = &argon_h264_name,
++ },
++ {
++ .compatible = "raspberrypi,argon-vp9-decoder",
++ .data = &argon_vp9_name,
++ },
++ /* The "intc" is included as this block of hardware contains the
++ * "frame done" status flags.
++ */
++ {
++ .compatible = "raspberrypi,argon-local-intc",
++ .data = &argon_intc_name,
++ },
++ { /* sentinel */ },
++};
++
++MODULE_DEVICE_TABLE(of, argon_mem_of_match);
++
++static struct platform_driver argon_mem_driver = {
++ .probe = argon_mem_probe,
++ .remove = argon_mem_remove,
++ .driver = {
++ .name = DRIVER_NAME,
++ .owner = THIS_MODULE,
++ .of_match_table = argon_mem_of_match,
++ },
++};
++
++module_platform_driver(argon_mem_driver);
++
++MODULE_ALIAS("platform:argon-mem");
++MODULE_LICENSE("GPL");
++MODULE_DESCRIPTION("Driver for accessing Argon decoder registers from userspace");
++MODULE_AUTHOR("Jonathan Bell <jonathan@raspberrypi.org>");
projects / openwrt / openwrt.git / blobdiff