On some new laptops the LCD panel has a builtin electronic privacy-screen. We want to export this functionality as a property on the drm connector object. But often this functionality is not exposed on the GPU but on some other (ACPI) device.
This commit adds a privacy-screen class allowing the driver for these other devices to register themselves as a privacy-screen provider; and allowing the drm/kms code to get a privacy-screen provider associated with a specific GPU/connector combo.
Signed-off-by: Hans de Goede hdegoede@redhat.com --- Documentation/gpu/drm-kms-helpers.rst | 15 + MAINTAINERS | 8 + drivers/gpu/drm/Kconfig | 5 + drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/drm_privacy_screen.c | 426 ++++++++++++++++++++++ include/drm/drm_privacy_screen_consumer.h | 27 ++ include/drm/drm_privacy_screen_driver.h | 80 ++++ include/drm/drm_privacy_screen_machine.h | 41 +++ 8 files changed, 603 insertions(+) create mode 100644 drivers/gpu/drm/drm_privacy_screen.c create mode 100644 include/drm/drm_privacy_screen_consumer.h create mode 100644 include/drm/drm_privacy_screen_driver.h create mode 100644 include/drm/drm_privacy_screen_machine.h
diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst index b411adb98960..8ce74f3f41d0 100644 --- a/Documentation/gpu/drm-kms-helpers.rst +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -424,3 +424,18 @@ SHMEM GEM Helper Reference
.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c :export: + +Privacy-screen class +==================== + +.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c + :doc: overview + +.. kernel-doc:: include/drm/drm_privacy_screen_driver.h + :internal: + +.. kernel-doc:: include/drm/drm_privacy_screen_machine.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c + :export: diff --git a/MAINTAINERS b/MAINTAINERS index f465eb96c303..9434f67e3c0b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5862,6 +5862,14 @@ F: drivers/gpu/drm/drm_panel.c F: drivers/gpu/drm/panel/ F: include/drm/drm_panel.h
+DRM PRIVACY-SCREEN CLASS +M: Hans de Goede hdegoede@redhat.com +L: dri-devel@lists.freedesktop.org +S: Maintained +T: git git://anongit.freedesktop.org/drm/drm-misc +F: drivers/gpu/drm/drm_privacy_screen* +F: include/drm/drm_privacy_screen* + DRM TTM SUBSYSTEM M: Christian Koenig christian.koenig@amd.com M: Huang Rui ray.huang@amd.com diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index c4fd57d8b717..5dbfabad1050 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -475,3 +475,8 @@ config DRM_PANEL_ORIENTATION_QUIRKS config DRM_LIB_RANDOM bool default n + +# Separate option, used by drivers outside of drivers/gpu/drm +config DRM_PRIVACY_SCREEN + tristate + default n diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 2c0e5a7e5953..621afac6e447 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_DRM) += drm.o obj-$(CONFIG_DRM_MIPI_DBI) += drm_mipi_dbi.o obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o +obj-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o obj-y += arm/ obj-$(CONFIG_DRM_TTM) += ttm/ obj-$(CONFIG_DRM_SCHED) += scheduler/ diff --git a/drivers/gpu/drm/drm_privacy_screen.c b/drivers/gpu/drm/drm_privacy_screen.c new file mode 100644 index 000000000000..6296fd46156c --- /dev/null +++ b/drivers/gpu/drm/drm_privacy_screen.c @@ -0,0 +1,426 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright (C) 2020 Red Hat, Inc. + * + * Authors: + * Hans de Goede hdegoede@redhat.com + */ + +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <drm/drm_privacy_screen_machine.h> +#include <drm/drm_privacy_screen_consumer.h> +#include <drm/drm_privacy_screen_driver.h> + +/** + * DOC: overview + * + * This class allows non KMS drivers, from e.g. drivers/platform/x86 to + * register a privacy-screen device, which the KMS drivers can then use + * to implement the standard privacy-screen properties, see + * :ref:`Standard Connector Properties<standard_connector_properties>`. + * + * KMS drivers using a privacy-screen class device are advised to use the + * drm_connector_attach_privacy_screen_provider() and + * drm_connector_update_privacy_screen() helpers for dealing with this. + */ + +#define to_drm_privacy_screen(dev) \ + container_of(dev, struct drm_privacy_screen, dev) + +static DEFINE_MUTEX(drm_privacy_screen_lookup_lock); +static LIST_HEAD(drm_privacy_screen_lookup_list); + +static DEFINE_MUTEX(drm_privacy_screen_devs_lock); +static LIST_HEAD(drm_privacy_screen_devs); + +/*** drm_privacy_screen_machine.h functions ***/ + +/** + * drm_privacy_screen_lookup_add - add an entry to the static privacy-screen + * lookup list + * @lookup: lookup list entry to add + * + * Add an entry to the static privacy-screen lookup list. Note the + * &struct list_head which is part of the &struct drm_privacy_screen_lookup + * gets added to a list owned by the privacy-screen core. So the passed in + * &struct drm_privacy_screen_lookup must not be free-ed until it is removed + * from the lookup list by calling drm_privacy_screen_lookup_remove(). + */ +void drm_privacy_screen_lookup_add(struct drm_privacy_screen_lookup *lookup) +{ + mutex_lock(&drm_privacy_screen_lookup_lock); + list_add(&lookup->list, &drm_privacy_screen_lookup_list); + mutex_unlock(&drm_privacy_screen_lookup_lock); +} +EXPORT_SYMBOL(drm_privacy_screen_lookup_add); + +/** + * drm_privacy_screen_lookup_remove - remove an entry to the static + * privacy-screen lookup list + * @lookup: lookup list entry to remove + * + * Remove an entry previously added with drm_privacy_screen_lookup_add() + * from the static privacy-screen lookup list. + */ +void drm_privacy_screen_lookup_remove(struct drm_privacy_screen_lookup *lookup) +{ + mutex_lock(&drm_privacy_screen_lookup_lock); + list_del(&lookup->list); + mutex_unlock(&drm_privacy_screen_lookup_lock); +} +EXPORT_SYMBOL(drm_privacy_screen_lookup_remove); + +/*** drm_privacy_screen_consumer.h functions ***/ + +static struct drm_privacy_screen *drm_privacy_screen_get_by_name( + const char *name) +{ + struct drm_privacy_screen *priv; + struct device *dev = NULL; + + mutex_lock(&drm_privacy_screen_devs_lock); + + list_for_each_entry(priv, &drm_privacy_screen_devs, list) { + if (strcmp(dev_name(&priv->dev), name) == 0) { + dev = get_device(&priv->dev); + break; + } + } + + mutex_unlock(&drm_privacy_screen_devs_lock); + + return dev ? to_drm_privacy_screen(dev) : NULL; +} + +/** + * drm_privacy_screen_get - get a privacy-screen provider + * @dev: consumer-device for which to get a privacy-screen provider + * @con_id: (video)connector name for which to get a privacy-screen provider + * + * Get a privacy-screen provider for a privacy-screen attached to the + * display described by the @dev and @con_id parameters. + * + * Return: + * * A pointer to a &struct drm_privacy_screen on success. + * * ERR_PTR(-ENODEV) if no matching privacy-screen is found + * * ERR_PTR(-EPROBE_DEFER) if there is a matching privacy-screen, + * but it has not been registered yet. + */ +struct drm_privacy_screen *drm_privacy_screen_get(struct device *dev, + const char *con_id) +{ + const char *dev_id = dev ? dev_name(dev) : NULL; + struct drm_privacy_screen_lookup *l; + struct drm_privacy_screen *priv; + const char *provider = NULL; + int match, best = -1; + + /* + * For now we only support using a static lookup table, which is + * populated by the drm_privacy_screen_arch_init() call. This should + * be extended with device-tree / fw_node lookup when support is added + * for device-tree using hardware with a privacy-screen. + * + * The lookup algorithm was shamelessly taken from the clock + * framework: + * + * We do slightly fuzzy matching here: + * An entry with a NULL ID is assumed to be a wildcard. + * If an entry has a device ID, it must match + * If an entry has a connection ID, it must match + * Then we take the most specific entry - with the following order + * of precedence: dev+con > dev only > con only. + */ + mutex_lock(&drm_privacy_screen_lookup_lock); + + list_for_each_entry(l, &drm_privacy_screen_lookup_list, list) { + match = 0; + + if (l->dev_id) { + if (!dev_id || strcmp(l->dev_id, dev_id)) + continue; + + match += 2; + } + + if (l->con_id) { + if (!con_id || strcmp(l->con_id, con_id)) + continue; + + match += 1; + } + + if (match > best) { + provider = l->provider; + best = match; + } + } + + mutex_unlock(&drm_privacy_screen_lookup_lock); + + if (!provider) + return ERR_PTR(-ENODEV); + + priv = drm_privacy_screen_get_by_name(provider); + if (!priv) + return ERR_PTR(-EPROBE_DEFER); + + return priv; +} +EXPORT_SYMBOL(drm_privacy_screen_get); + +/** + * drm_privacy_screen_put - release a privacy-screen reference + * @priv: privacy screen reference to release + * + * Release a privacy-screen provider reference gotten through + * drm_privacy_screen_get(). May be called with a NULL or ERR_PTR, + * in which case it is a no-op. + */ +void drm_privacy_screen_put(struct drm_privacy_screen *priv) +{ + if (IS_ERR_OR_NULL(priv)) + return; + + put_device(&priv->dev); +} +EXPORT_SYMBOL(drm_privacy_screen_put); + +/** + * drm_privacy_screen_set_sw_state - set a privacy-screen's sw-state + * @priv: privacy screen to set the sw-state for + * @sw_state: new sw-state value to set + * + * Set the sw-state of a privacy screen. If the privacy-screen is not + * in a locked hw-state, then the actual and hw-state of the privacy-screen + * will be immediately updated to the new value. If the privacy-screen is + * in a locked hw-state, then the new sw-state will be remembered as the + * requested state to put the privacy-screen in when it becomes unlocked. + * + * Return: 0 on success, negative error code on failure. + */ +int drm_privacy_screen_set_sw_state(struct drm_privacy_screen *priv, + enum drm_privacy_screen_status sw_state) +{ + int ret = 0; + + mutex_lock(&priv->lock); + + if (!priv->ops) { + ret = -ENODEV; + goto out; + } + + /* + * As per the DRM connector properties documentation, setting the + * sw_state while the hw_state is locked is allowed. In this case + * it is a no-op other then storing the new sw_state so that it + * can be honored when the state gets unlocked. + */ + if (priv->hw_state >= PRIVACY_SCREEN_DISABLED_LOCKED) { + priv->sw_state = sw_state; + goto out; + } + + ret = priv->ops->set_sw_state(priv, sw_state); +out: + mutex_unlock(&priv->lock); + return ret; +} +EXPORT_SYMBOL(drm_privacy_screen_set_sw_state); + +/** + * drm_privacy_screen_get_state - get privacy-screen's current state + * @priv: privacy screen to get the state for + * @sw_state_ret: address where to store the privacy-screens current sw-state + * @hw_state_ret: address where to store the privacy-screens current hw-state + * + * Get the current state of a privacy-screen, both the sw-state and the + * hw-state. + */ +void drm_privacy_screen_get_state(struct drm_privacy_screen *priv, + enum drm_privacy_screen_status *sw_state_ret, + enum drm_privacy_screen_status *hw_state_ret) +{ + mutex_lock(&priv->lock); + *sw_state_ret = priv->sw_state; + *hw_state_ret = priv->hw_state; + mutex_unlock(&priv->lock); +} +EXPORT_SYMBOL(drm_privacy_screen_get_state); + +/*** drm_privacy_screen_driver.h functions ***/ + +static ssize_t sw_state_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct drm_privacy_screen *priv = to_drm_privacy_screen(dev); + const char * const sw_state_names[] = { + "Disabled", + "Enabled", + }; + ssize_t ret; + + mutex_lock(&priv->lock); + + if (!priv->ops) + ret = -ENODEV; + else if (WARN_ON(priv->sw_state >= ARRAY_SIZE(sw_state_names))) + ret = -ENXIO; + else + ret = sprintf(buf, "%s\n", sw_state_names[priv->sw_state]); + + mutex_unlock(&priv->lock); + return ret; +} +/* + * RO: Do not allow setting the sw_state through sysfs, this MUST be done + * through the drm_properties on the drm_connector. + */ +static DEVICE_ATTR_RO(sw_state); + +static ssize_t hw_state_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct drm_privacy_screen *priv = to_drm_privacy_screen(dev); + const char * const hw_state_names[] = { + "Disabled", + "Enabled", + "Disabled, locked", + "Enabled, locked", + }; + ssize_t ret; + + mutex_lock(&priv->lock); + + if (!priv->ops) + ret = -ENODEV; + else if (WARN_ON(priv->hw_state >= ARRAY_SIZE(hw_state_names))) + ret = -ENXIO; + else + ret = sprintf(buf, "%s\n", hw_state_names[priv->hw_state]); + + mutex_unlock(&priv->lock); + return ret; +} +static DEVICE_ATTR_RO(hw_state); + +static struct attribute *drm_privacy_screen_attrs[] = { + &dev_attr_sw_state.attr, + &dev_attr_hw_state.attr, + NULL +}; +ATTRIBUTE_GROUPS(drm_privacy_screen); + +static struct class drm_privacy_screen_class = { + .name = "privacy_screen", + .owner = THIS_MODULE, + .dev_groups = drm_privacy_screen_groups, +}; + +static void drm_privacy_screen_device_release(struct device *dev) +{ + struct drm_privacy_screen *priv = to_drm_privacy_screen(dev); + + kfree(priv); +} + +/** + * drm_privacy_screen_register - register a privacy-screen + * @parent: parent-device for the privacy-screen + * @ops: &struct drm_privacy_screen_ops pointer with ops for the privacy-screen + * + * Create and register a privacy-screen. + * + * Return: + * * A pointer to the created privacy-screen on success. + * * An ERR_PTR(errno) on failure. + */ +struct drm_privacy_screen *drm_privacy_screen_register( + struct device *parent, const struct drm_privacy_screen_ops *ops) +{ + struct drm_privacy_screen *priv; + int ret; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return ERR_PTR(-ENOMEM); + + mutex_init(&priv->lock); + + priv->dev.class = &drm_privacy_screen_class; + priv->dev.parent = parent; + priv->dev.release = drm_privacy_screen_device_release; + dev_set_name(&priv->dev, "%s", dev_name(parent)); + priv->ops = ops; + + priv->ops->get_hw_state(priv); + + ret = device_register(&priv->dev); + if (ret) { + put_device(&priv->dev); + return ERR_PTR(ret); + } + + mutex_lock(&drm_privacy_screen_devs_lock); + list_add(&priv->list, &drm_privacy_screen_devs); + mutex_unlock(&drm_privacy_screen_devs_lock); + + return priv; +} +EXPORT_SYMBOL(drm_privacy_screen_register); + +/** + * drm_privacy_screen_unregister - unregister privacy-screen + * @priv: privacy-screen to unregister + * + * Unregister a privacy-screen registered with drm_privacy_screen_register(). + * May be called with a NULL or ERR_PTR, in which case it is a no-op. + */ +void drm_privacy_screen_unregister(struct drm_privacy_screen *priv) +{ + if (IS_ERR_OR_NULL(priv)) + return; + + mutex_lock(&drm_privacy_screen_devs_lock); + list_del(&priv->list); + mutex_unlock(&drm_privacy_screen_devs_lock); + + mutex_lock(&priv->lock); + priv->ops = NULL; + mutex_unlock(&priv->lock); + + device_unregister(&priv->dev); +} +EXPORT_SYMBOL(drm_privacy_screen_unregister); + +static int __init drm_privacy_screen_init(void) +{ + int ret; + + ret = class_register(&drm_privacy_screen_class); + if (ret) + return ret; + + drm_privacy_screen_arch_init(); + + return 0; +} + +static void __exit drm_privacy_screen_exit(void) +{ + drm_privacy_screen_arch_exit(); + class_unregister(&drm_privacy_screen_class); +} + +subsys_initcall(drm_privacy_screen_init); +module_exit(drm_privacy_screen_exit); + +MODULE_AUTHOR("Hans de Goede"); +MODULE_DESCRIPTION("DRM privacy-screen class"); +MODULE_LICENSE("GPL and additional rights"); diff --git a/include/drm/drm_privacy_screen_consumer.h b/include/drm/drm_privacy_screen_consumer.h new file mode 100644 index 000000000000..169ba72bd60d --- /dev/null +++ b/include/drm/drm_privacy_screen_consumer.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright (C) 2020 Red Hat, Inc. + * + * Authors: + * Hans de Goede hdegoede@redhat.com + */ + +#ifndef __DRM_PRIVACY_SCREEN_CONSUMER_H__ +#define __DRM_PRIVACY_SCREEN_CONSUMER_H__ + +#include <linux/device.h> +#include <drm/drm_connector.h> + +struct drm_privacy_screen; + +struct drm_privacy_screen *drm_privacy_screen_get(struct device *dev, + const char *con_id); +void drm_privacy_screen_put(struct drm_privacy_screen *priv); + +int drm_privacy_screen_set_sw_state(struct drm_privacy_screen *priv, + enum drm_privacy_screen_status sw_state); +void drm_privacy_screen_get_state(struct drm_privacy_screen *priv, + enum drm_privacy_screen_status *sw_state_ret, + enum drm_privacy_screen_status *hw_state_ret); + +#endif diff --git a/include/drm/drm_privacy_screen_driver.h b/include/drm/drm_privacy_screen_driver.h new file mode 100644 index 000000000000..5187ae52eb03 --- /dev/null +++ b/include/drm/drm_privacy_screen_driver.h @@ -0,0 +1,80 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright (C) 2020 Red Hat, Inc. + * + * Authors: + * Hans de Goede hdegoede@redhat.com + */ + +#ifndef __DRM_PRIVACY_SCREEN_DRIVER_H__ +#define __DRM_PRIVACY_SCREEN_DRIVER_H__ + +#include <linux/device.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <drm/drm_connector.h> + +struct drm_privacy_screen; + +/** + * struct drm_privacy_screen_ops - drm_privacy_screen operations + * + * Defines the operations which the privacy-screen class code may call. + * These functions should be implemented by the privacy-screen driver. + */ +struct drm_privacy_screen_ops { + /** + * @set_sw_state: Called to request a change of the privacy-screen + * state. The privacy-screen class code contains a check to avoid this + * getting called when the hw_state reports the state is locked. + * It is the driver's responsibility to update sw_state and hw_state. + * This is always called with the drm_privacy_screen's lock held. + */ + int (*set_sw_state)(struct drm_privacy_screen *priv, + enum drm_privacy_screen_status sw_state); + /** + * @get_hw_state: Called to request that the driver gets the current + * privacy-screen state from the hardware and then updates sw_state and + * hw_state accordingly. This will be called by the core just before + * the privacy-screen is registered in sysfs. + */ + void (*get_hw_state)(struct drm_privacy_screen *priv); +}; + +/** + * struct drm_privacy_screen - central privacy-screen structure + * + * Central privacy-screen structure, this contains the struct device used + * to register the screen in sysfs, the screen's state, ops, etc. + */ +struct drm_privacy_screen { + /** @dev: device used to register the privacy-screen in sysfs. */ + struct device dev; + /** @lock: mutex protection all fields in this struct. */ + struct mutex lock; + /** @list: privacy-screen devices list list-entry. */ + struct list_head list; + /** + * @ops: &struct drm_privacy_screen_ops for this privacy-screen. + * This is NULL if the driver has unregistered the privacy-screen. + */ + const struct drm_privacy_screen_ops *ops; + /** + * @sw_state: The privacy-screen's software state, see + * :ref:`Standard Connector Properties<standard_connector_properties>` + * for more info. + */ + enum drm_privacy_screen_status sw_state; + /** + * @hw_state: The privacy-screen's hardware state, see + * :ref:`Standard Connector Properties<standard_connector_properties>` + * for more info. + */ + enum drm_privacy_screen_status hw_state; +}; + +struct drm_privacy_screen *drm_privacy_screen_register( + struct device *parent, const struct drm_privacy_screen_ops *ops); +void drm_privacy_screen_unregister(struct drm_privacy_screen *priv); + +#endif diff --git a/include/drm/drm_privacy_screen_machine.h b/include/drm/drm_privacy_screen_machine.h new file mode 100644 index 000000000000..55f4b4fd8e4e --- /dev/null +++ b/include/drm/drm_privacy_screen_machine.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright (C) 2020 Red Hat, Inc. + * + * Authors: + * Hans de Goede hdegoede@redhat.com + */ + +#ifndef __DRM_PRIVACY_SCREEN_MACHINE_H__ +#define __DRM_PRIVACY_SCREEN_MACHINE_H__ + +#include <linux/list.h> + +/** + * struct drm_privacy_screen_lookup - static privacy-screen lookup list entry + * + * Used for the static lookup-list for mapping privacy-screen consumer + * dev-connector pairs to a privacy-screen provider. + */ +struct drm_privacy_screen_lookup { + /** @list: Lookup list list-entry. */ + struct list_head list; + /** @dev_id: Consumer device name or NULL to match all devices. */ + const char *dev_id; + /** @con_id: Consumer connector name or NULL to match all connectors. */ + const char *con_id; + /** @provider: dev_name() of the privacy_screen provider. */ + const char *provider; +}; + +void drm_privacy_screen_lookup_add(struct drm_privacy_screen_lookup *lookup); +void drm_privacy_screen_lookup_remove(struct drm_privacy_screen_lookup *lookup); + +static inline void drm_privacy_screen_arch_init(void) +{ +} +static inline void drm_privacy_screen_arch_exit(void) +{ +} + +#endif