--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Mediated virtual PCI display host device driver
+ *
+ * See mdpy-defs.h for device specs
+ *
+ * (c) Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * based on mtty driver which is:
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia <cjia@nvidia.com>
+ * Kirti Wankhede <kwankhede@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/cdev.h>
+#include <linux/vfio.h>
+#include <linux/iommu.h>
+#include <linux/sysfs.h>
+#include <linux/mdev.h>
+#include <linux/pci.h>
+#include <drm/drm_fourcc.h>
+#include "mdpy-defs.h"
+
+#define MDPY_NAME "mdpy"
+#define MDPY_CLASS_NAME "mdpy"
+
+#define MDPY_CONFIG_SPACE_SIZE 0xff
+#define MDPY_MEMORY_BAR_OFFSET PAGE_SIZE
+#define MDPY_DISPLAY_REGION 16
+
+#define STORE_LE16(addr, val) (*(u16 *)addr = val)
+#define STORE_LE32(addr, val) (*(u32 *)addr = val)
+
+
+MODULE_LICENSE("GPL v2");
+
+static int max_devices = 4;
+module_param_named(count, max_devices, int, 0444);
+MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices");
+
+
+#define MDPY_TYPE_1 "vga"
+#define MDPY_TYPE_2 "xga"
+#define MDPY_TYPE_3 "hd"
+
+static const struct mdpy_type {
+ const char *name;
+ u32 format;
+ u32 bytepp;
+ u32 width;
+ u32 height;
+} mdpy_types[] = {
+ {
+ .name = MDPY_CLASS_NAME "-" MDPY_TYPE_1,
+ .format = DRM_FORMAT_XRGB8888,
+ .bytepp = 4,
+ .width = 640,
+ .height = 480,
+ }, {
+ .name = MDPY_CLASS_NAME "-" MDPY_TYPE_2,
+ .format = DRM_FORMAT_XRGB8888,
+ .bytepp = 4,
+ .width = 1024,
+ .height = 768,
+ }, {
+ .name = MDPY_CLASS_NAME "-" MDPY_TYPE_3,
+ .format = DRM_FORMAT_XRGB8888,
+ .bytepp = 4,
+ .width = 1920,
+ .height = 1080,
+ },
+};
+
+static dev_t mdpy_devt;
+static struct class *mdpy_class;
+static struct cdev mdpy_cdev;
+static struct device mdpy_dev;
+static u32 mdpy_count;
+
+/* State of each mdev device */
+struct mdev_state {
+ u8 *vconfig;
+ u32 bar_mask;
+ struct mutex ops_lock;
+ struct mdev_device *mdev;
+ struct vfio_device_info dev_info;
+
+ const struct mdpy_type *type;
+ u32 memsize;
+ void *memblk;
+};
+
+static const struct mdpy_type *mdpy_find_type(struct kobject *kobj)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(mdpy_types); i++)
+ if (strcmp(mdpy_types[i].name, kobj->name) == 0)
+ return mdpy_types + i;
+ return NULL;
+}
+
+static void mdpy_create_config_space(struct mdev_state *mdev_state)
+{
+ STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
+ MDPY_PCI_VENDOR_ID);
+ STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
+ MDPY_PCI_DEVICE_ID);
+ STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
+ MDPY_PCI_SUBVENDOR_ID);
+ STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
+ MDPY_PCI_SUBDEVICE_ID);
+
+ STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
+ PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
+ STORE_LE16((u16 *) &mdev_state->vconfig[PCI_STATUS],
+ PCI_STATUS_CAP_LIST);
+ STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
+ PCI_CLASS_DISPLAY_OTHER);
+ mdev_state->vconfig[PCI_CLASS_REVISION] = 0x01;
+
+ STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
+ PCI_BASE_ADDRESS_SPACE_MEMORY |
+ PCI_BASE_ADDRESS_MEM_TYPE_32 |
+ PCI_BASE_ADDRESS_MEM_PREFETCH);
+ mdev_state->bar_mask = ~(mdev_state->memsize) + 1;
+
+ /* vendor specific capability for the config registers */
+ mdev_state->vconfig[PCI_CAPABILITY_LIST] = MDPY_VENDORCAP_OFFSET;
+ mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 0] = 0x09; /* vendor cap */
+ mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 1] = 0x00; /* next ptr */
+ mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 2] = MDPY_VENDORCAP_SIZE;
+ STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_FORMAT_OFFSET],
+ mdev_state->type->format);
+ STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_WIDTH_OFFSET],
+ mdev_state->type->width);
+ STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_HEIGHT_OFFSET],
+ mdev_state->type->height);
+}
+
+static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
+ char *buf, u32 count)
+{
+ struct device *dev = mdev_dev(mdev_state->mdev);
+ u32 cfg_addr;
+
+ switch (offset) {
+ case PCI_BASE_ADDRESS_0:
+ cfg_addr = *(u32 *)buf;
+
+ if (cfg_addr == 0xffffffff) {
+ cfg_addr = (cfg_addr & mdev_state->bar_mask);
+ } else {
+ cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
+ if (cfg_addr)
+ dev_info(dev, "BAR0 @ 0x%x\n", cfg_addr);
+ }
+
+ cfg_addr |= (mdev_state->vconfig[offset] &
+ ~PCI_BASE_ADDRESS_MEM_MASK);
+ STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
+ break;
+ }
+}
+
+static ssize_t mdev_access(struct mdev_device *mdev, char *buf, size_t count,
+ loff_t pos, bool is_write)
+{
+ struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
+ struct device *dev = mdev_dev(mdev);
+ int ret = 0;
+
+ mutex_lock(&mdev_state->ops_lock);
+
+ if (pos < MDPY_CONFIG_SPACE_SIZE) {
+ if (is_write)
+ handle_pci_cfg_write(mdev_state, pos, buf, count);
+ else
+ memcpy(buf, (mdev_state->vconfig + pos), count);
+
+ } else if ((pos >= MDPY_MEMORY_BAR_OFFSET) &&
+ (pos + count <=
+ MDPY_MEMORY_BAR_OFFSET + mdev_state->memsize)) {
+ pos -= MDPY_MEMORY_BAR_OFFSET;
+ if (is_write)
+ memcpy(mdev_state->memblk, buf, count);
+ else
+ memcpy(buf, mdev_state->memblk, count);
+
+ } else {
+ dev_info(dev, "%s: %s @0x%llx (unhandled)\n",
+ __func__, is_write ? "WR" : "RD", pos);
+ ret = -1;
+ goto accessfailed;
+ }
+
+ ret = count;
+
+
+accessfailed:
+ mutex_unlock(&mdev_state->ops_lock);
+
+ return ret;
+}
+
+static int mdpy_reset(struct mdev_device *mdev)
+{
+ struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
+ u32 stride, i;
+
+ /* initialize with gray gradient */
+ stride = mdev_state->type->width * mdev_state->type->bytepp;
+ for (i = 0; i < mdev_state->type->height; i++)
+ memset(mdev_state->memblk + i * stride,
+ i * 255 / mdev_state->type->height,
+ stride);
+ return 0;
+}
+
+static int mdpy_create(struct kobject *kobj, struct mdev_device *mdev)
+{
+ const struct mdpy_type *type = mdpy_find_type(kobj);
+ struct device *dev = mdev_dev(mdev);
+ struct mdev_state *mdev_state;
+ u32 fbsize;
+
+ if (mdpy_count >= max_devices)
+ return -ENOMEM;
+
+ mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
+ if (mdev_state == NULL)
+ return -ENOMEM;
+
+ mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL);
+ if (mdev_state->vconfig == NULL) {
+ kfree(mdev_state);
+ return -ENOMEM;
+ }
+
+ if (!type)
+ type = &mdpy_types[0];
+ fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp);
+
+ mdev_state->memblk = vmalloc_user(fbsize);
+ if (!mdev_state->memblk) {
+ kfree(mdev_state->vconfig);
+ kfree(mdev_state);
+ return -ENOMEM;
+ }
+ dev_info(dev, "%s: %s (%dx%d)\n",
+ __func__, kobj->name, type->width, type->height);
+
+ mutex_init(&mdev_state->ops_lock);
+ mdev_state->mdev = mdev;
+ mdev_set_drvdata(mdev, mdev_state);
+
+ mdev_state->type = type;
+ mdev_state->memsize = fbsize;
+ mdpy_create_config_space(mdev_state);
+ mdpy_reset(mdev);
+
+ mdpy_count++;
+ return 0;
+}
+
+static int mdpy_remove(struct mdev_device *mdev)
+{
+ struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
+ struct device *dev = mdev_dev(mdev);
+
+ dev_info(dev, "%s\n", __func__);
+
+ mdev_set_drvdata(mdev, NULL);
+ vfree(mdev_state->memblk);
+ kfree(mdev_state->vconfig);
+ kfree(mdev_state);
+
+ mdpy_count--;
+ return 0;
+}
+
+static ssize_t mdpy_read(struct mdev_device *mdev, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned int done = 0;
+ int ret;
+
+ while (count) {
+ size_t filled;
+
+ if (count >= 4 && !(*ppos % 4)) {
+ u32 val;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, false);
+ if (ret <= 0)
+ goto read_err;
+
+ if (copy_to_user(buf, &val, sizeof(val)))
+ goto read_err;
+
+ filled = 4;
+ } else if (count >= 2 && !(*ppos % 2)) {
+ u16 val;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, false);
+ if (ret <= 0)
+ goto read_err;
+
+ if (copy_to_user(buf, &val, sizeof(val)))
+ goto read_err;
+
+ filled = 2;
+ } else {
+ u8 val;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, false);
+ if (ret <= 0)
+ goto read_err;
+
+ if (copy_to_user(buf, &val, sizeof(val)))
+ goto read_err;
+
+ filled = 1;
+ }
+
+ count -= filled;
+ done += filled;
+ *ppos += filled;
+ buf += filled;
+ }
+
+ return done;
+
+read_err:
+ return -EFAULT;
+}
+
+static ssize_t mdpy_write(struct mdev_device *mdev, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned int done = 0;
+ int ret;
+
+ while (count) {
+ size_t filled;
+
+ if (count >= 4 && !(*ppos % 4)) {
+ u32 val;
+
+ if (copy_from_user(&val, buf, sizeof(val)))
+ goto write_err;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, true);
+ if (ret <= 0)
+ goto write_err;
+
+ filled = 4;
+ } else if (count >= 2 && !(*ppos % 2)) {
+ u16 val;
+
+ if (copy_from_user(&val, buf, sizeof(val)))
+ goto write_err;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, true);
+ if (ret <= 0)
+ goto write_err;
+
+ filled = 2;
+ } else {
+ u8 val;
+
+ if (copy_from_user(&val, buf, sizeof(val)))
+ goto write_err;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, true);
+ if (ret <= 0)
+ goto write_err;
+
+ filled = 1;
+ }
+ count -= filled;
+ done += filled;
+ *ppos += filled;
+ buf += filled;
+ }
+
+ return done;
+write_err:
+ return -EFAULT;
+}
+
+static int mdpy_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
+{
+ struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
+
+ if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
+ return -EINVAL;
+ if (vma->vm_end < vma->vm_start)
+ return -EINVAL;
+ if (vma->vm_end - vma->vm_start > mdev_state->memsize)
+ return -EINVAL;
+ if ((vma->vm_flags & VM_SHARED) == 0)
+ return -EINVAL;
+
+ return remap_vmalloc_range_partial(vma, vma->vm_start,
+ mdev_state->memblk,
+ vma->vm_end - vma->vm_start);
+}
+
+static int mdpy_get_region_info(struct mdev_device *mdev,
+ struct vfio_region_info *region_info,
+ u16 *cap_type_id, void **cap_type)
+{
+ struct mdev_state *mdev_state;
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state)
+ return -EINVAL;
+
+ if (region_info->index >= VFIO_PCI_NUM_REGIONS &&
+ region_info->index != MDPY_DISPLAY_REGION)
+ return -EINVAL;
+
+ switch (region_info->index) {
+ case VFIO_PCI_CONFIG_REGION_INDEX:
+ region_info->offset = 0;
+ region_info->size = MDPY_CONFIG_SPACE_SIZE;
+ region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE);
+ break;
+ case VFIO_PCI_BAR0_REGION_INDEX:
+ case MDPY_DISPLAY_REGION:
+ region_info->offset = MDPY_MEMORY_BAR_OFFSET;
+ region_info->size = mdev_state->memsize;
+ region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE |
+ VFIO_REGION_INFO_FLAG_MMAP);
+ break;
+ default:
+ region_info->size = 0;
+ region_info->offset = 0;
+ region_info->flags = 0;
+ }
+
+ return 0;
+}
+
+static int mdpy_get_irq_info(struct mdev_device *mdev,
+ struct vfio_irq_info *irq_info)
+{
+ irq_info->count = 0;
+ return 0;
+}
+
+static int mdpy_get_device_info(struct mdev_device *mdev,
+ struct vfio_device_info *dev_info)
+{
+ dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
+ dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
+ dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
+ return 0;
+}
+
+static int mdpy_query_gfx_plane(struct mdev_device *mdev,
+ struct vfio_device_gfx_plane_info *plane)
+{
+ struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
+
+ if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
+ if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
+ VFIO_GFX_PLANE_TYPE_REGION))
+ return 0;
+ return -EINVAL;
+ }
+
+ if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION)
+ return -EINVAL;
+
+ plane->drm_format = mdev_state->type->format;
+ plane->width = mdev_state->type->width;
+ plane->height = mdev_state->type->height;
+ plane->stride = (mdev_state->type->width *
+ mdev_state->type->bytepp);
+ plane->size = mdev_state->memsize;
+ plane->region_index = MDPY_DISPLAY_REGION;
+
+ /* unused */
+ plane->drm_format_mod = 0;
+ plane->x_pos = 0;
+ plane->y_pos = 0;
+ plane->x_hot = 0;
+ plane->y_hot = 0;
+
+ return 0;
+}
+
+static long mdpy_ioctl(struct mdev_device *mdev, unsigned int cmd,
+ unsigned long arg)
+{
+ int ret = 0;
+ unsigned long minsz;
+ struct mdev_state *mdev_state;
+
+ mdev_state = mdev_get_drvdata(mdev);
+
+ switch (cmd) {
+ case VFIO_DEVICE_GET_INFO:
+ {
+ struct vfio_device_info info;
+
+ minsz = offsetofend(struct vfio_device_info, num_irqs);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz)
+ return -EINVAL;
+
+ ret = mdpy_get_device_info(mdev, &info);
+ if (ret)
+ return ret;
+
+ memcpy(&mdev_state->dev_info, &info, sizeof(info));
+
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+
+ return 0;
+ }
+ case VFIO_DEVICE_GET_REGION_INFO:
+ {
+ struct vfio_region_info info;
+ u16 cap_type_id = 0;
+ void *cap_type = NULL;
+
+ minsz = offsetofend(struct vfio_region_info, offset);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz)
+ return -EINVAL;
+
+ ret = mdpy_get_region_info(mdev, &info, &cap_type_id,
+ &cap_type);
+ if (ret)
+ return ret;
+
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+
+ return 0;
+ }
+
+ case VFIO_DEVICE_GET_IRQ_INFO:
+ {
+ struct vfio_irq_info info;
+
+ minsz = offsetofend(struct vfio_irq_info, count);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if ((info.argsz < minsz) ||
+ (info.index >= mdev_state->dev_info.num_irqs))
+ return -EINVAL;
+
+ ret = mdpy_get_irq_info(mdev, &info);
+ if (ret)
+ return ret;
+
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+
+ return 0;
+ }
+
+ case VFIO_DEVICE_QUERY_GFX_PLANE:
+ {
+ struct vfio_device_gfx_plane_info plane;
+
+ minsz = offsetofend(struct vfio_device_gfx_plane_info,
+ region_index);
+
+ if (copy_from_user(&plane, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (plane.argsz < minsz)
+ return -EINVAL;
+
+ ret = mdpy_query_gfx_plane(mdev, &plane);
+ if (ret)
+ return ret;
+
+ if (copy_to_user((void __user *)arg, &plane, minsz))
+ return -EFAULT;
+
+ return 0;
+ }
+
+ case VFIO_DEVICE_SET_IRQS:
+ return -EINVAL;
+
+ case VFIO_DEVICE_RESET:
+ return mdpy_reset(mdev);
+ }
+ return -ENOTTY;
+}
+
+static int mdpy_open(struct mdev_device *mdev)
+{
+ if (!try_module_get(THIS_MODULE))
+ return -ENODEV;
+
+ return 0;
+}
+
+static void mdpy_close(struct mdev_device *mdev)
+{
+ module_put(THIS_MODULE);
+}
+
+static ssize_t
+resolution_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
+
+ return sprintf(buf, "%dx%d\n",
+ mdev_state->type->width,
+ mdev_state->type->height);
+}
+static DEVICE_ATTR_RO(resolution);
+
+static struct attribute *mdev_dev_attrs[] = {
+ &dev_attr_resolution.attr,
+ NULL,
+};
+
+static const struct attribute_group mdev_dev_group = {
+ .name = "vendor",
+ .attrs = mdev_dev_attrs,
+};
+
+const struct attribute_group *mdev_dev_groups[] = {
+ &mdev_dev_group,
+ NULL,
+};
+
+static ssize_t
+name_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ return sprintf(buf, "%s\n", kobj->name);
+}
+MDEV_TYPE_ATTR_RO(name);
+
+static ssize_t
+description_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ const struct mdpy_type *type = mdpy_find_type(kobj);
+
+ return sprintf(buf, "virtual display, %dx%d framebuffer\n",
+ type ? type->width : 0,
+ type ? type->height : 0);
+}
+MDEV_TYPE_ATTR_RO(description);
+
+static ssize_t
+available_instances_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ return sprintf(buf, "%d\n", max_devices - mdpy_count);
+}
+MDEV_TYPE_ATTR_RO(available_instances);
+
+static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
+ char *buf)
+{
+ return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
+}
+MDEV_TYPE_ATTR_RO(device_api);
+
+static struct attribute *mdev_types_attrs[] = {
+ &mdev_type_attr_name.attr,
+ &mdev_type_attr_description.attr,
+ &mdev_type_attr_device_api.attr,
+ &mdev_type_attr_available_instances.attr,
+ NULL,
+};
+
+static struct attribute_group mdev_type_group1 = {
+ .name = MDPY_TYPE_1,
+ .attrs = mdev_types_attrs,
+};
+
+static struct attribute_group mdev_type_group2 = {
+ .name = MDPY_TYPE_2,
+ .attrs = mdev_types_attrs,
+};
+
+static struct attribute_group mdev_type_group3 = {
+ .name = MDPY_TYPE_3,
+ .attrs = mdev_types_attrs,
+};
+
+static struct attribute_group *mdev_type_groups[] = {
+ &mdev_type_group1,
+ &mdev_type_group2,
+ &mdev_type_group3,
+ NULL,
+};
+
+static const struct mdev_parent_ops mdev_fops = {
+ .owner = THIS_MODULE,
+ .mdev_attr_groups = mdev_dev_groups,
+ .supported_type_groups = mdev_type_groups,
+ .create = mdpy_create,
+ .remove = mdpy_remove,
+ .open = mdpy_open,
+ .release = mdpy_close,
+ .read = mdpy_read,
+ .write = mdpy_write,
+ .ioctl = mdpy_ioctl,
+ .mmap = mdpy_mmap,
+};
+
+static const struct file_operations vd_fops = {
+ .owner = THIS_MODULE,
+};
+
+static void mdpy_device_release(struct device *dev)
+{
+ /* nothing */
+}
+
+static int __init mdpy_dev_init(void)
+{
+ int ret = 0;
+
+ ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK, MDPY_NAME);
+ if (ret < 0) {
+ pr_err("Error: failed to register mdpy_dev, err: %d\n", ret);
+ return ret;
+ }
+ cdev_init(&mdpy_cdev, &vd_fops);
+ cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK);
+ pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt));
+
+ mdpy_class = class_create(THIS_MODULE, MDPY_CLASS_NAME);
+ if (IS_ERR(mdpy_class)) {
+ pr_err("Error: failed to register mdpy_dev class\n");
+ ret = PTR_ERR(mdpy_class);
+ goto failed1;
+ }
+ mdpy_dev.class = mdpy_class;
+ mdpy_dev.release = mdpy_device_release;
+ dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
+
+ ret = device_register(&mdpy_dev);
+ if (ret)
+ goto failed2;
+
+ ret = mdev_register_device(&mdpy_dev, &mdev_fops);
+ if (ret)
+ goto failed3;
+
+ return 0;
+
+failed3:
+ device_unregister(&mdpy_dev);
+failed2:
+ class_destroy(mdpy_class);
+failed1:
+ cdev_del(&mdpy_cdev);
+ unregister_chrdev_region(mdpy_devt, MINORMASK);
+ return ret;
+}
+
+static void __exit mdpy_dev_exit(void)
+{
+ mdpy_dev.bus = NULL;
+ mdev_unregister_device(&mdpy_dev);
+
+ device_unregister(&mdpy_dev);
+ cdev_del(&mdpy_cdev);
+ unregister_chrdev_region(mdpy_devt, MINORMASK);
+ class_destroy(mdpy_class);
+ mdpy_class = NULL;
+}
+
+module_init(mdpy_dev_init)
+module_exit(mdpy_dev_exit)
projects / platform / kernel / linux-rpi.git / commitdiff