From da68386d9edb1f57abf886febe5c5169ebd4d2c9 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Thu, 21 Apr 2022 09:31:02 +0200 Subject: drm: Rename dp/ to display/ Rename dp/ to display/ to account for additional display-related helpers, such as HDMI. Update all related include statements. No functional changes. Various drivers, such as i915 and amdgpu, use similar naming scheme by putting code for video-output standards into a local display/ directory. The new directory's name is aligned with this convention. v2: * update commit message (Javier) Signed-off-by: Thomas Zimmermann Reviewed-by: Lyude Paul Reviewed-by: Javier Martinez Canillas Reviewed-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-3-tzimmermann@suse.de --- drivers/gpu/drm/display/drm_dp_aux_dev.c | 354 +++++++++++++++++++++++++++++++ 1 file changed, 354 insertions(+) create mode 100644 drivers/gpu/drm/display/drm_dp_aux_dev.c (limited to 'drivers/gpu/drm/display/drm_dp_aux_dev.c') diff --git a/drivers/gpu/drm/display/drm_dp_aux_dev.c b/drivers/gpu/drm/display/drm_dp_aux_dev.c new file mode 100644 index 000000000000..098e482e65a2 --- /dev/null +++ b/drivers/gpu/drm/display/drm_dp_aux_dev.c @@ -0,0 +1,354 @@ +/* + * Copyright © 2015 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + * + * Authors: + * Rafael Antognolli + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "drm_dp_helper_internal.h" + +struct drm_dp_aux_dev { + unsigned index; + struct drm_dp_aux *aux; + struct device *dev; + struct kref refcount; + atomic_t usecount; +}; + +#define DRM_AUX_MINORS 256 +#define AUX_MAX_OFFSET (1 << 20) +static DEFINE_IDR(aux_idr); +static DEFINE_MUTEX(aux_idr_mutex); +static struct class *drm_dp_aux_dev_class; +static int drm_dev_major = -1; + +static struct drm_dp_aux_dev *drm_dp_aux_dev_get_by_minor(unsigned index) +{ + struct drm_dp_aux_dev *aux_dev = NULL; + + mutex_lock(&aux_idr_mutex); + aux_dev = idr_find(&aux_idr, index); + if (aux_dev && !kref_get_unless_zero(&aux_dev->refcount)) + aux_dev = NULL; + mutex_unlock(&aux_idr_mutex); + + return aux_dev; +} + +static struct drm_dp_aux_dev *alloc_drm_dp_aux_dev(struct drm_dp_aux *aux) +{ + struct drm_dp_aux_dev *aux_dev; + int index; + + aux_dev = kzalloc(sizeof(*aux_dev), GFP_KERNEL); + if (!aux_dev) + return ERR_PTR(-ENOMEM); + aux_dev->aux = aux; + atomic_set(&aux_dev->usecount, 1); + kref_init(&aux_dev->refcount); + + mutex_lock(&aux_idr_mutex); + index = idr_alloc(&aux_idr, aux_dev, 0, DRM_AUX_MINORS, GFP_KERNEL); + mutex_unlock(&aux_idr_mutex); + if (index < 0) { + kfree(aux_dev); + return ERR_PTR(index); + } + aux_dev->index = index; + + return aux_dev; +} + +static void release_drm_dp_aux_dev(struct kref *ref) +{ + struct drm_dp_aux_dev *aux_dev = + container_of(ref, struct drm_dp_aux_dev, refcount); + + kfree(aux_dev); +} + +static ssize_t name_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + ssize_t res; + struct drm_dp_aux_dev *aux_dev = + drm_dp_aux_dev_get_by_minor(MINOR(dev->devt)); + + if (!aux_dev) + return -ENODEV; + + res = sprintf(buf, "%s\n", aux_dev->aux->name); + kref_put(&aux_dev->refcount, release_drm_dp_aux_dev); + + return res; +} +static DEVICE_ATTR_RO(name); + +static struct attribute *drm_dp_aux_attrs[] = { + &dev_attr_name.attr, + NULL, +}; +ATTRIBUTE_GROUPS(drm_dp_aux); + +static int auxdev_open(struct inode *inode, struct file *file) +{ + unsigned int minor = iminor(inode); + struct drm_dp_aux_dev *aux_dev; + + aux_dev = drm_dp_aux_dev_get_by_minor(minor); + if (!aux_dev) + return -ENODEV; + + file->private_data = aux_dev; + return 0; +} + +static loff_t auxdev_llseek(struct file *file, loff_t offset, int whence) +{ + return fixed_size_llseek(file, offset, whence, AUX_MAX_OFFSET); +} + +static ssize_t auxdev_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct drm_dp_aux_dev *aux_dev = iocb->ki_filp->private_data; + loff_t pos = iocb->ki_pos; + ssize_t res = 0; + + if (!atomic_inc_not_zero(&aux_dev->usecount)) + return -ENODEV; + + iov_iter_truncate(to, AUX_MAX_OFFSET - pos); + + while (iov_iter_count(to)) { + uint8_t buf[DP_AUX_MAX_PAYLOAD_BYTES]; + ssize_t todo = min(iov_iter_count(to), sizeof(buf)); + + if (signal_pending(current)) { + res = -ERESTARTSYS; + break; + } + + res = drm_dp_dpcd_read(aux_dev->aux, pos, buf, todo); + + if (res <= 0) + break; + + if (copy_to_iter(buf, res, to) != res) { + res = -EFAULT; + break; + } + + pos += res; + } + + if (pos != iocb->ki_pos) + res = pos - iocb->ki_pos; + iocb->ki_pos = pos; + + if (atomic_dec_and_test(&aux_dev->usecount)) + wake_up_var(&aux_dev->usecount); + + return res; +} + +static ssize_t auxdev_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct drm_dp_aux_dev *aux_dev = iocb->ki_filp->private_data; + loff_t pos = iocb->ki_pos; + ssize_t res = 0; + + if (!atomic_inc_not_zero(&aux_dev->usecount)) + return -ENODEV; + + iov_iter_truncate(from, AUX_MAX_OFFSET - pos); + + while (iov_iter_count(from)) { + uint8_t buf[DP_AUX_MAX_PAYLOAD_BYTES]; + ssize_t todo = min(iov_iter_count(from), sizeof(buf)); + + if (signal_pending(current)) { + res = -ERESTARTSYS; + break; + } + + if (!copy_from_iter_full(buf, todo, from)) { + res = -EFAULT; + break; + } + + res = drm_dp_dpcd_write(aux_dev->aux, pos, buf, todo); + + if (res <= 0) + break; + + pos += res; + } + + if (pos != iocb->ki_pos) + res = pos - iocb->ki_pos; + iocb->ki_pos = pos; + + if (atomic_dec_and_test(&aux_dev->usecount)) + wake_up_var(&aux_dev->usecount); + + return res; +} + +static int auxdev_release(struct inode *inode, struct file *file) +{ + struct drm_dp_aux_dev *aux_dev = file->private_data; + + kref_put(&aux_dev->refcount, release_drm_dp_aux_dev); + return 0; +} + +static const struct file_operations auxdev_fops = { + .owner = THIS_MODULE, + .llseek = auxdev_llseek, + .read_iter = auxdev_read_iter, + .write_iter = auxdev_write_iter, + .open = auxdev_open, + .release = auxdev_release, +}; + +#define to_auxdev(d) container_of(d, struct drm_dp_aux_dev, aux) + +static struct drm_dp_aux_dev *drm_dp_aux_dev_get_by_aux(struct drm_dp_aux *aux) +{ + struct drm_dp_aux_dev *iter, *aux_dev = NULL; + int id; + + /* don't increase kref count here because this function should only be + * used by drm_dp_aux_unregister_devnode. Thus, it will always have at + * least one reference - the one that drm_dp_aux_register_devnode + * created + */ + mutex_lock(&aux_idr_mutex); + idr_for_each_entry(&aux_idr, iter, id) { + if (iter->aux == aux) { + aux_dev = iter; + break; + } + } + mutex_unlock(&aux_idr_mutex); + return aux_dev; +} + +void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux) +{ + struct drm_dp_aux_dev *aux_dev; + unsigned int minor; + + aux_dev = drm_dp_aux_dev_get_by_aux(aux); + if (!aux_dev) /* attach must have failed */ + return; + + /* + * As some AUX adapters may exist as platform devices which outlive their respective DRM + * devices, we clear drm_dev to ensure that we never accidentally reference a stale pointer + */ + aux->drm_dev = NULL; + + mutex_lock(&aux_idr_mutex); + idr_remove(&aux_idr, aux_dev->index); + mutex_unlock(&aux_idr_mutex); + + atomic_dec(&aux_dev->usecount); + wait_var_event(&aux_dev->usecount, !atomic_read(&aux_dev->usecount)); + + minor = aux_dev->index; + if (aux_dev->dev) + device_destroy(drm_dp_aux_dev_class, + MKDEV(drm_dev_major, minor)); + + DRM_DEBUG("drm_dp_aux_dev: aux [%s] unregistering\n", aux->name); + kref_put(&aux_dev->refcount, release_drm_dp_aux_dev); +} + +int drm_dp_aux_register_devnode(struct drm_dp_aux *aux) +{ + struct drm_dp_aux_dev *aux_dev; + int res; + + aux_dev = alloc_drm_dp_aux_dev(aux); + if (IS_ERR(aux_dev)) + return PTR_ERR(aux_dev); + + aux_dev->dev = device_create(drm_dp_aux_dev_class, aux->dev, + MKDEV(drm_dev_major, aux_dev->index), NULL, + "drm_dp_aux%d", aux_dev->index); + if (IS_ERR(aux_dev->dev)) { + res = PTR_ERR(aux_dev->dev); + aux_dev->dev = NULL; + goto error; + } + + DRM_DEBUG("drm_dp_aux_dev: aux [%s] registered as minor %d\n", + aux->name, aux_dev->index); + return 0; +error: + drm_dp_aux_unregister_devnode(aux); + return res; +} + +int drm_dp_aux_dev_init(void) +{ + int res; + + drm_dp_aux_dev_class = class_create(THIS_MODULE, "drm_dp_aux_dev"); + if (IS_ERR(drm_dp_aux_dev_class)) { + return PTR_ERR(drm_dp_aux_dev_class); + } + drm_dp_aux_dev_class->dev_groups = drm_dp_aux_groups; + + res = register_chrdev(0, "aux", &auxdev_fops); + if (res < 0) + goto out; + drm_dev_major = res; + + return 0; +out: + class_destroy(drm_dp_aux_dev_class); + return res; +} + +void drm_dp_aux_dev_exit(void) +{ + unregister_chrdev(drm_dev_major, "aux"); + class_destroy(drm_dp_aux_dev_class); +} -- cgit v1.2.3