diff options
| -rw-r--r-- | drivers/gpu/drm/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/gpu/drm/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_dp_aux_dev.c | 368 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 16 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_kms_helper_common.c | 15 | ||||
| -rw-r--r-- | include/drm/drm_dp_aux_dev.h | 62 |
6 files changed, 468 insertions, 2 deletions
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 8ae7ab68cb97..7b1560792e6a 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -25,6 +25,14 @@ config DRM_MIPI_DSI bool depends on DRM +config DRM_DP_AUX_CHARDEV + bool "DRM DP AUX Interface" + depends on DRM + help + Choose this option to enable a /dev/drm_dp_auxN node that allows to + read and write values to arbitrary DPCD registers on the DP aux + channel. + config DRM_KMS_HELPER tristate depends on DRM diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index f619ff4b22a2..e07fd93981e1 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -28,6 +28,7 @@ drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \ drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o +drm_kms_helper-$(CONFIG_DRM_DP_AUX_CHARDEV) += drm_dp_aux_dev.o obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o diff --git a/drivers/gpu/drm/drm_dp_aux_dev.c b/drivers/gpu/drm/drm_dp_aux_dev.c new file mode 100644 index 000000000000..f73b38b33a8e --- /dev/null +++ b/drivers/gpu/drm/drm_dp_aux_dev.c @@ -0,0 +1,368 @@ +/* + * 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 <rafael.antognolli@intel.com> + * + */ + +#include <linux/device.h> +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/uaccess.h> +#include <drm/drm_dp_helper.h> +#include <drm/drm_crtc.h> +#include <drm/drmP.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 (!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_cyclic(&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(struct file *file, char __user *buf, size_t count, + loff_t *offset) +{ + size_t bytes_pending, num_bytes_processed = 0; + struct drm_dp_aux_dev *aux_dev = file->private_data; + ssize_t res = 0; + + if (!atomic_inc_not_zero(&aux_dev->usecount)) + return -ENODEV; + + bytes_pending = min((loff_t)count, AUX_MAX_OFFSET - (*offset)); + + if (!access_ok(VERIFY_WRITE, buf, bytes_pending)) { + res = -EFAULT; + goto out; + } + + while (bytes_pending > 0) { + uint8_t localbuf[DP_AUX_MAX_PAYLOAD_BYTES]; + ssize_t todo = min_t(size_t, bytes_pending, sizeof(localbuf)); + + res = drm_dp_dpcd_read(aux_dev->aux, *offset, localbuf, todo); + if (res <= 0) { + res = num_bytes_processed ? num_bytes_processed : res; + goto out; + } + if (__copy_to_user(buf + num_bytes_processed, localbuf, res)) { + res = num_bytes_processed ? + num_bytes_processed : -EFAULT; + goto out; + } + bytes_pending -= res; + *offset += res; + num_bytes_processed += res; + res = num_bytes_processed; + } + +out: + atomic_dec(&aux_dev->usecount); + wake_up_atomic_t(&aux_dev->usecount); + return res; +} + +static ssize_t auxdev_write(struct file *file, const char __user *buf, + size_t count, loff_t *offset) +{ + size_t bytes_pending, num_bytes_processed = 0; + struct drm_dp_aux_dev *aux_dev = file->private_data; + ssize_t res = 0; + + if (!atomic_inc_not_zero(&aux_dev->usecount)) + return -ENODEV; + + bytes_pending = min((loff_t)count, AUX_MAX_OFFSET - *offset); + + if (!access_ok(VERIFY_READ, buf, bytes_pending)) { + res = -EFAULT; + goto out; + } + + while (bytes_pending > 0) { + uint8_t localbuf[DP_AUX_MAX_PAYLOAD_BYTES]; + ssize_t todo = min_t(size_t, bytes_pending, sizeof(localbuf)); + + if (__copy_from_user(localbuf, + buf + num_bytes_processed, todo)) { + res = num_bytes_processed ? + num_bytes_processed : -EFAULT; + goto out; + } + + res = drm_dp_dpcd_write(aux_dev->aux, *offset, localbuf, todo); + if (res <= 0) { + res = num_bytes_processed ? num_bytes_processed : res; + goto out; + } + bytes_pending -= res; + *offset += res; + num_bytes_processed += res; + res = num_bytes_processed; + } + +out: + atomic_dec(&aux_dev->usecount); + wake_up_atomic_t(&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 = auxdev_read, + .write = auxdev_write, + .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; +} + +static int auxdev_wait_atomic_t(atomic_t *p) +{ + schedule(); + return 0; +} +/** + * drm_dp_aux_unregister_devnode() - unregister a devnode for this aux channel + * @aux: DisplayPort AUX channel + * + * Returns 0 on success or a negative error code on failure. + */ +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; + + mutex_lock(&aux_idr_mutex); + idr_remove(&aux_idr, aux_dev->index); + mutex_unlock(&aux_idr_mutex); + + atomic_dec(&aux_dev->usecount); + wait_on_atomic_t(&aux_dev->usecount, auxdev_wait_atomic_t, + TASK_UNINTERRUPTIBLE); + + 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); +} +EXPORT_SYMBOL(drm_dp_aux_unregister_devnode); + +/** + * drm_dp_aux_register_devnode() - register a devnode for this aux channel + * @aux: DisplayPort AUX channel + * + * Returns 0 on success or a negative error code on failure. + */ +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; +} +EXPORT_SYMBOL(drm_dp_aux_register_devnode); + +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)) { + res = PTR_ERR(drm_dp_aux_dev_class); + goto out; + } + 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; +} +EXPORT_SYMBOL(drm_dp_aux_dev_init); + +void drm_dp_aux_dev_exit(void) +{ + unregister_chrdev(drm_dev_major, "aux"); + class_destroy(drm_dp_aux_dev_class); +} +EXPORT_SYMBOL(drm_dp_aux_dev_exit); diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 9535c5b60387..7d58f594cffe 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -28,6 +28,7 @@ #include <linux/sched.h> #include <linux/i2c.h> #include <drm/drm_dp_helper.h> +#include <drm/drm_dp_aux_dev.h> #include <drm/drmP.h> /** @@ -754,6 +755,8 @@ static const struct i2c_algorithm drm_dp_i2c_algo = { */ int drm_dp_aux_register(struct drm_dp_aux *aux) { + int ret; + mutex_init(&aux->hw_mutex); aux->ddc.algo = &drm_dp_i2c_algo; @@ -768,7 +771,17 @@ int drm_dp_aux_register(struct drm_dp_aux *aux) strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev), sizeof(aux->ddc.name)); - return i2c_add_adapter(&aux->ddc); + ret = drm_dp_aux_register_devnode(aux); + if (ret) + return ret; + + ret = i2c_add_adapter(&aux->ddc); + if (ret) { + drm_dp_aux_unregister_devnode(aux); + return ret; + } + + return 0; } EXPORT_SYMBOL(drm_dp_aux_register); @@ -778,6 +791,7 @@ EXPORT_SYMBOL(drm_dp_aux_register); */ void drm_dp_aux_unregister(struct drm_dp_aux *aux) { + drm_dp_aux_unregister_devnode(aux); i2c_del_adapter(&aux->ddc); } EXPORT_SYMBOL(drm_dp_aux_unregister); diff --git a/drivers/gpu/drm/drm_kms_helper_common.c b/drivers/gpu/drm/drm_kms_helper_common.c index d3610058de3c..3187c4bb01cb 100644 --- a/drivers/gpu/drm/drm_kms_helper_common.c +++ b/drivers/gpu/drm/drm_kms_helper_common.c @@ -27,6 +27,7 @@ #include <drm/drmP.h> #include <drm/drm_fb_helper.h> +#include <drm/drm_dp_aux_dev.h> MODULE_AUTHOR("David Airlie, Jesse Barnes"); MODULE_DESCRIPTION("DRM KMS helper"); @@ -34,13 +35,25 @@ MODULE_LICENSE("GPL and additional rights"); static int __init drm_kms_helper_init(void) { + int ret; + /* Call init functions from specific kms helpers here */ - return drm_fb_helper_modinit(); + ret = drm_fb_helper_modinit(); + if (ret < 0) + goto out; + + ret = drm_dp_aux_dev_init(); + if (ret < 0) + goto out; + +out: + return ret; } static void __exit drm_kms_helper_exit(void) { /* Call exit functions from specific kms helpers here */ + drm_dp_aux_dev_exit(); } module_init(drm_kms_helper_init); diff --git a/include/drm/drm_dp_aux_dev.h b/include/drm/drm_dp_aux_dev.h new file mode 100644 index 000000000000..1b76d990d8ab --- /dev/null +++ b/include/drm/drm_dp_aux_dev.h @@ -0,0 +1,62 @@ +/* + * 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 <rafael.antognolli@intel.com> + * + */ + +#ifndef DRM_DP_AUX_DEV +#define DRM_DP_AUX_DEV + +#include <drm/drm_dp_helper.h> + +#ifdef CONFIG_DRM_DP_AUX_CHARDEV + +int drm_dp_aux_dev_init(void); +void drm_dp_aux_dev_exit(void); +int drm_dp_aux_register_devnode(struct drm_dp_aux *aux); +void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux); + +#else + +static inline int drm_dp_aux_dev_init(void) +{ + return 0; +} + +static inline void drm_dp_aux_dev_exit(void) +{ +} + +static inline int drm_dp_aux_register_devnode(struct drm_dp_aux *aux) +{ + return 0; +} + +static inline void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux) +{ +} + +#endif + +#endif |