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.

Changes in v2: - Make CONFIG_DRM_PRIVACY_SCREEN a bool which controls if the drm_privacy code gets built as part of the main drm module rather then making it a tristate which builds its own module. - Add a #if IS_ENABLED(CONFIG_DRM_PRIVACY_SCREEN) check to drm_privacy_screen_consumer.h and define stubs when the check fails. Together these 2 changes fix several dependency issues. - Remove module related code now that this is part of the main drm.ko - Use drm_class as class for the privacy-screen devices instead of adding a separate class for this

Changes in v3: - Make the static inline drm_privacy_screen_get_state() stub set sw_state and hw_state to PRIVACY_SCREEN_DISABLED to squelch an uninitialized variable warning when CONFIG_DRM_PRIVICAY_SCREEN is not set

Changes in v4: - Make drm_privacy_screen_set_sw_state() skip calling out to the hw if hw_state == new_sw_state

Reviewed-by: Emil Velikov emil.l.velikov@gmail.com Reviewed-by: Lyude Paul lyude@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com --- Documentation/gpu/drm-kms-helpers.rst | 15 + MAINTAINERS | 8 + drivers/gpu/drm/Kconfig | 4 + drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/drm_drv.c | 4 + drivers/gpu/drm/drm_privacy_screen.c | 403 ++++++++++++++++++++++ include/drm/drm_privacy_screen_consumer.h | 50 +++ include/drm/drm_privacy_screen_driver.h | 80 +++++ include/drm/drm_privacy_screen_machine.h | 41 +++ 9 files changed, 606 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 ec2f65b31930..5bb55ec1b9b5 100644 --- a/Documentation/gpu/drm-kms-helpers.rst +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -435,3 +435,18 @@ Legacy CRTC/Modeset Helper Functions Reference

.. kernel-doc:: drivers/gpu/drm/drm_crtc_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 e3556c63081d..0e70c81d3ddc 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6421,6 +6421,14 @@ 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 2a926d0de423..c686c08447ac 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -481,3 +481,7 @@ config DRM_PANEL_ORIENTATION_QUIRKS config DRM_LIB_RANDOM bool default n + +config DRM_PRIVACY_SCREEN + bool + default n diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 0dff40bb863c..788fc37096f6 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -32,6 +32,7 @@ drm-$(CONFIG_OF) += drm_of.o drm-$(CONFIG_PCI) += drm_pci.o drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o +drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o

obj-$(CONFIG_DRM_DP_AUX_BUS) += drm_dp_aux_bus.o

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 7a5097467ba5..dc293b771c3f 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -43,6 +43,7 @@ #include <drm/drm_managed.h> #include <drm/drm_mode_object.h> #include <drm/drm_print.h> +#include <drm/drm_privacy_screen_machine.h>

#include "drm_crtc_internal.h" #include "drm_internal.h" @@ -1029,6 +1030,7 @@ static const struct file_operations drm_stub_fops = {

static void drm_core_exit(void) { + drm_privacy_screen_lookup_exit(); unregister_chrdev(DRM_MAJOR, "drm"); debugfs_remove(drm_debugfs_root); drm_sysfs_destroy(); @@ -1056,6 +1058,8 @@ static int __init drm_core_init(void) if (ret < 0) goto error;

+ drm_privacy_screen_lookup_init(); + drm_core_init_complete = true;

DRM_DEBUG("Initialized\n"); diff --git a/drivers/gpu/drm/drm_privacy_screen.c b/drivers/gpu/drm/drm_privacy_screen.c new file mode 100644 index 000000000000..183a6011adf0 --- /dev/null +++ b/drivers/gpu/drm/drm_privacy_screen.c @@ -0,0 +1,403 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright (C) 2020 - 2021 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> +#include "drm_internal.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. + * Also skip the set if the hw already is in the desired state. + */ + if (priv->hw_state >= PRIVACY_SCREEN_DISABLED_LOCKED || + priv->hw_state == sw_state) { + 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 device_type drm_privacy_screen_type = { + .name = "privacy_screen", + .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_class; + priv->dev.type = &drm_privacy_screen_type; + priv->dev.parent = parent; + priv->dev.release = drm_privacy_screen_device_release; + dev_set_name(&priv->dev, "privacy_screen-%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); diff --git a/include/drm/drm_privacy_screen_consumer.h b/include/drm/drm_privacy_screen_consumer.h new file mode 100644 index 000000000000..0cbd23b0453d --- /dev/null +++ b/include/drm/drm_privacy_screen_consumer.h @@ -0,0 +1,50 @@ +/* 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; + +#if IS_ENABLED(CONFIG_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); +#else +static inline struct drm_privacy_screen *drm_privacy_screen_get(struct device *dev, + const char *con_id) +{ + return ERR_PTR(-ENODEV); +} +static inline void drm_privacy_screen_put(struct drm_privacy_screen *priv) +{ +} +static inline int drm_privacy_screen_set_sw_state(struct drm_privacy_screen *priv, + enum drm_privacy_screen_status sw_state) +{ + return -ENODEV; +} +static inline 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) +{ + *sw_state_ret = PRIVACY_SCREEN_DISABLED; + *hw_state_ret = PRIVACY_SCREEN_DISABLED; +} +#endif + +#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..aaa0d38cce92 --- /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_lookup_init(void) +{ +} +static inline void drm_privacy_screen_lookup_exit(void) +{ +} + +#endif

Add support for privacy-screen consumers to register a notifier to be notified of external (e.g. done by the hw itself on a hotkey press) state changes.

Changes in v2: - Drop WARN_ON(mutex_is_locked(&priv->lock)) check in drm_privacy_screen_call_notifier_chain() it may be locked by another thread, which would lead to a false-positive triggering of the check

Reviewed-by: Emil Velikov emil.l.velikov@gmail.com Reviewed-by: Lyude Paul lyude@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com --- drivers/gpu/drm/drm_privacy_screen.c | 64 +++++++++++++++++++++++ include/drm/drm_privacy_screen_consumer.h | 15 ++++++ include/drm/drm_privacy_screen_driver.h | 4 ++ 3 files changed, 83 insertions(+)

diff --git a/drivers/gpu/drm/drm_privacy_screen.c b/drivers/gpu/drm/drm_privacy_screen.c index 183a6011adf0..beaf99e9120a 100644 --- a/drivers/gpu/drm/drm_privacy_screen.c +++ b/drivers/gpu/drm/drm_privacy_screen.c @@ -257,6 +257,49 @@ void drm_privacy_screen_get_state(struct drm_privacy_screen *priv, } EXPORT_SYMBOL(drm_privacy_screen_get_state);

+/** + * drm_privacy_screen_register_notifier - register a notifier + * @priv: Privacy screen to register the notifier with + * @nb: Notifier-block for the notifier to register + * + * Register a notifier with the privacy-screen to be notified of changes made + * to the privacy-screen state from outside of the privacy-screen class. + * E.g. the state may be changed by the hardware itself in response to a + * hotkey press. + * + * The notifier is called with no locks held. The new hw_state and sw_state + * can be retrieved using the drm_privacy_screen_get_state() function. + * A pointer to the drm_privacy_screen's struct is passed as the void *data + * argument of the notifier_block's notifier_call. + * + * The notifier will NOT be called when changes are made through + * drm_privacy_screen_set_sw_state(). It is only called for external changes. + * + * Return: 0 on success, negative error code on failure. + */ +int drm_privacy_screen_register_notifier(struct drm_privacy_screen *priv, + struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&priv->notifier_head, nb); +} +EXPORT_SYMBOL(drm_privacy_screen_register_notifier); + +/** + * drm_privacy_screen_unregister_notifier - unregister a notifier + * @priv: Privacy screen to register the notifier with + * @nb: Notifier-block for the notifier to register + * + * Unregister a notifier registered with drm_privacy_screen_register_notifier(). + * + * Return: 0 on success, negative error code on failure. + */ +int drm_privacy_screen_unregister_notifier(struct drm_privacy_screen *priv, + struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&priv->notifier_head, nb); +} +EXPORT_SYMBOL(drm_privacy_screen_unregister_notifier); + /*** drm_privacy_screen_driver.h functions ***/

static ssize_t sw_state_show(struct device *dev, @@ -354,6 +397,7 @@ struct drm_privacy_screen *drm_privacy_screen_register( return ERR_PTR(-ENOMEM);

mutex_init(&priv->lock); + BLOCKING_INIT_NOTIFIER_HEAD(&priv->notifier_head);

priv->dev.class = drm_class; priv->dev.type = &drm_privacy_screen_type; @@ -401,3 +445,23 @@ void drm_privacy_screen_unregister(struct drm_privacy_screen *priv) device_unregister(&priv->dev); } EXPORT_SYMBOL(drm_privacy_screen_unregister); + +/** + * drm_privacy_screen_call_notifier_chain - notify consumers of state change + * @priv: Privacy screen to register the notifier with + * + * A privacy-screen provider driver can call this functions upon external + * changes to the privacy-screen state. E.g. the state may be changed by the + * hardware itself in response to a hotkey press. + * This function must be called without holding the privacy-screen lock. + * the driver must update sw_state and hw_state to reflect the new state before + * calling this function. + * The expected behavior from the driver upon receiving an external state + * change event is: 1. Take the lock; 2. Update sw_state and hw_state; + * 3. Release the lock. 4. Call drm_privacy_screen_call_notifier_chain(). + */ +void drm_privacy_screen_call_notifier_chain(struct drm_privacy_screen *priv) +{ + blocking_notifier_call_chain(&priv->notifier_head, 0, priv); +} +EXPORT_SYMBOL(drm_privacy_screen_call_notifier_chain); diff --git a/include/drm/drm_privacy_screen_consumer.h b/include/drm/drm_privacy_screen_consumer.h index 0cbd23b0453d..7f66a90d15b7 100644 --- a/include/drm/drm_privacy_screen_consumer.h +++ b/include/drm/drm_privacy_screen_consumer.h @@ -24,6 +24,11 @@ int drm_privacy_screen_set_sw_state(struct drm_privacy_screen *priv, 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); + +int drm_privacy_screen_register_notifier(struct drm_privacy_screen *priv, + struct notifier_block *nb); +int drm_privacy_screen_unregister_notifier(struct drm_privacy_screen *priv, + struct notifier_block *nb); #else static inline struct drm_privacy_screen *drm_privacy_screen_get(struct device *dev, const char *con_id) @@ -45,6 +50,16 @@ static inline void drm_privacy_screen_get_state(struct drm_privacy_screen *priv, *sw_state_ret = PRIVACY_SCREEN_DISABLED; *hw_state_ret = PRIVACY_SCREEN_DISABLED; } +static inline int drm_privacy_screen_register_notifier(struct drm_privacy_screen *priv, + struct notifier_block *nb) +{ + return -ENODEV; +} +static inline int drm_privacy_screen_unregister_notifier(struct drm_privacy_screen *priv, + struct notifier_block *nb) +{ + return -ENODEV; +} #endif

#endif diff --git a/include/drm/drm_privacy_screen_driver.h b/include/drm/drm_privacy_screen_driver.h index 5187ae52eb03..24591b607675 100644 --- a/include/drm/drm_privacy_screen_driver.h +++ b/include/drm/drm_privacy_screen_driver.h @@ -54,6 +54,8 @@ struct drm_privacy_screen { struct mutex lock; /** @list: privacy-screen devices list list-entry. */ struct list_head list; + /** @notifier_head: privacy-screen notifier head. */ + struct blocking_notifier_head notifier_head; /** * @ops: &struct drm_privacy_screen_ops for this privacy-screen. * This is NULL if the driver has unregistered the privacy-screen. @@ -77,4 +79,6 @@ 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);

+void drm_privacy_screen_call_notifier_chain(struct drm_privacy_screen *priv); + #endif

Factor the extended hotkey handling out of hotkey_notify_hotkey() and into a new hotkey_notify_extended_hotkey() helper.

This is a preparation patch for adding support the privacy-screen hotkey toggle (which needs some special handling, it should NOT send an evdev key-event to userspace...).

Reviewed-by: Emil Velikov emil.l.velikov@gmail.com Reviewed-by: Lyude Paul lyude@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com --- drivers/platform/x86/thinkpad_acpi.c | 30 ++++++++++++++++++---------- 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 50ff04c84650..83c88a8ebaf2 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -3885,6 +3885,24 @@ static bool adaptive_keyboard_hotkey_notify_hotkey(unsigned int scancode) } }

+static bool hotkey_notify_extended_hotkey(const u32 hkey) +{ + unsigned int scancode; + + /* Extended keycodes start at 0x300 and our offset into the map + * TP_ACPI_HOTKEYSCAN_EXTENDED_START. The calculated scancode + * will be positive, but might not be in the correct range. + */ + scancode = (hkey & 0xfff) - (0x300 - TP_ACPI_HOTKEYSCAN_EXTENDED_START); + if (scancode >= TP_ACPI_HOTKEYSCAN_EXTENDED_START && + scancode < TPACPI_HOTKEY_MAP_LEN) { + tpacpi_input_send_key(scancode); + return true; + } + + return false; +} + static bool hotkey_notify_hotkey(const u32 hkey, bool *send_acpi_ev, bool *ignore_acpi_ev) @@ -3919,17 +3937,7 @@ static bool hotkey_notify_hotkey(const u32 hkey, return adaptive_keyboard_hotkey_notify_hotkey(scancode);

case 3: - /* Extended keycodes start at 0x300 and our offset into the map - * TP_ACPI_HOTKEYSCAN_EXTENDED_START. The calculated scancode - * will be positive, but might not be in the correct range. - */ - scancode -= (0x300 - TP_ACPI_HOTKEYSCAN_EXTENDED_START); - if (scancode >= TP_ACPI_HOTKEYSCAN_EXTENDED_START && - scancode < TPACPI_HOTKEY_MAP_LEN) { - tpacpi_input_send_key(scancode); - return true; - } - break; + return hotkey_notify_extended_hotkey(hkey); }

return false;

Register a privacy-screen device on laptops with a privacy-screen, this exports the PrivacyGuard features to user-space using a standardized vendor-agnostic sysfs interface. Note the sysfs interface is read-only.

Registering a privacy-screen device with the new privacy-screen class code will also allow the GPU driver to get a handle to it and export the privacy-screen setting as a property on the DRM connector object for the LCD panel. This DRM connector property is a new standardized interface which all user-space code should use to query and control the privacy-screen.

Reviewed-by: Emil Velikov emil.l.velikov@gmail.com Reviewed-by: Lyude Paul lyude@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com --- Changes in v3: - On receiving a TP_HKEY_EV_PRIVACYGUARD_TOGGLE event only call drm_privacy_screen_call_notifier_chain() if the privacy-screen state has actually changed

Changes in v2: - Make the new lcdshadow_set_sw_state, lcdshadow_get_hw_state and lcdshadow_ops symbols static - Update state and call drm_privacy_screen_call_notifier_chain() when the state is changed by pressing the Fn + D hotkey combo --- drivers/platform/x86/Kconfig | 2 + drivers/platform/x86/thinkpad_acpi.c | 97 +++++++++++++++++++++------- 2 files changed, 74 insertions(+), 25 deletions(-)

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index e21ea3d23e6f..20208207e366 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -501,7 +501,9 @@ config THINKPAD_ACPI depends on ACPI_VIDEO || ACPI_VIDEO = n depends on BACKLIGHT_CLASS_DEVICE depends on I2C + depends on DRM select ACPI_PLATFORM_PROFILE + select DRM_PRIVACY_SCREEN select HWMON select NVRAM select NEW_LEDS diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index b8f2556c4797..291cd18c9c8f 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -73,6 +73,7 @@ #include <linux/uaccess.h> #include <acpi/battery.h> #include <acpi/video.h> +#include <drm/drm_privacy_screen_driver.h> #include "dual_accel_detect.h"

/* ThinkPad CMOS commands */ @@ -157,6 +158,7 @@ enum tpacpi_hkey_event_t { TP_HKEY_EV_VOL_UP = 0x1015, /* Volume up or unmute */ TP_HKEY_EV_VOL_DOWN = 0x1016, /* Volume down or unmute */ TP_HKEY_EV_VOL_MUTE = 0x1017, /* Mixer output mute */ + TP_HKEY_EV_PRIVACYGUARD_TOGGLE = 0x130f, /* Toggle priv.guard on/off */

/* Reasons for waking up from S3/S4 */ TP_HKEY_EV_WKUP_S3_UNDOCK = 0x2304, /* undock requested, S3 */ @@ -3889,6 +3891,12 @@ static bool hotkey_notify_extended_hotkey(const u32 hkey) { unsigned int scancode;

+ switch (hkey) { + case TP_HKEY_EV_PRIVACYGUARD_TOGGLE: + tpacpi_driver_event(hkey); + return true; + } + /* Extended keycodes start at 0x300 and our offset into the map * TP_ACPI_HOTKEYSCAN_EXTENDED_START. The calculated scancode * will be positive, but might not be in the correct range. @@ -9819,30 +9827,40 @@ static struct ibm_struct battery_driver_data = { * LCD Shadow subdriver, for the Lenovo PrivacyGuard feature */

+static struct drm_privacy_screen *lcdshadow_dev; static acpi_handle lcdshadow_get_handle; static acpi_handle lcdshadow_set_handle; -static int lcdshadow_state;

-static int lcdshadow_on_off(bool state) +static int lcdshadow_set_sw_state(struct drm_privacy_screen *priv, + enum drm_privacy_screen_status state) { int output;

+ if (WARN_ON(!mutex_is_locked(&priv->lock))) + return -EIO; + if (!acpi_evalf(lcdshadow_set_handle, &output, NULL, "dd", (int)state)) return -EIO;

- lcdshadow_state = state; + priv->hw_state = priv->sw_state = state; return 0; }

-static int lcdshadow_set(bool on) +static void lcdshadow_get_hw_state(struct drm_privacy_screen *priv) { - if (lcdshadow_state < 0) - return lcdshadow_state; - if (lcdshadow_state == on) - return 0; - return lcdshadow_on_off(on); + int output; + + if (!acpi_evalf(lcdshadow_get_handle, &output, NULL, "dd", 0)) + return; + + priv->hw_state = priv->sw_state = output & 0x1; }

+static const struct drm_privacy_screen_ops lcdshadow_ops = { + .set_sw_state = lcdshadow_set_sw_state, + .get_hw_state = lcdshadow_get_hw_state, +}; + static int tpacpi_lcdshadow_init(struct ibm_init_struct *iibm) { acpi_status status1, status2; @@ -9850,36 +9868,44 @@ static int tpacpi_lcdshadow_init(struct ibm_init_struct *iibm)

status1 = acpi_get_handle(hkey_handle, "GSSS", &lcdshadow_get_handle); status2 = acpi_get_handle(hkey_handle, "SSSS", &lcdshadow_set_handle); - if (ACPI_FAILURE(status1) || ACPI_FAILURE(status2)) { - lcdshadow_state = -ENODEV; + if (ACPI_FAILURE(status1) || ACPI_FAILURE(status2)) return 0; - }

- if (!acpi_evalf(lcdshadow_get_handle, &output, NULL, "dd", 0)) { - lcdshadow_state = -EIO; + if (!acpi_evalf(lcdshadow_get_handle, &output, NULL, "dd", 0)) return -EIO; - } - if (!(output & 0x10000)) { - lcdshadow_state = -ENODEV; + + if (!(output & 0x10000)) return 0; - } - lcdshadow_state = output & 0x1; + + lcdshadow_dev = drm_privacy_screen_register(&tpacpi_pdev->dev, + &lcdshadow_ops); + if (IS_ERR(lcdshadow_dev)) + return PTR_ERR(lcdshadow_dev);

return 0; }

+static void lcdshadow_exit(void) +{ + drm_privacy_screen_unregister(lcdshadow_dev); +} + static void lcdshadow_resume(void) { - if (lcdshadow_state >= 0) - lcdshadow_on_off(lcdshadow_state); + if (!lcdshadow_dev) + return; + + mutex_lock(&lcdshadow_dev->lock); + lcdshadow_set_sw_state(lcdshadow_dev, lcdshadow_dev->sw_state); + mutex_unlock(&lcdshadow_dev->lock); }

static int lcdshadow_read(struct seq_file *m) { - if (lcdshadow_state < 0) { + if (!lcdshadow_dev) { seq_puts(m, "status:\t\tnot supported\n"); } else { - seq_printf(m, "status:\t\t%d\n", lcdshadow_state); + seq_printf(m, "status:\t\t%d\n", lcdshadow_dev->hw_state); seq_puts(m, "commands:\t0, 1\n"); }

@@ -9891,7 +9917,7 @@ static int lcdshadow_write(char *buf) char *cmd; int res, state = -EINVAL;

- if (lcdshadow_state < 0) + if (!lcdshadow_dev) return -ENODEV;

while ((cmd = strsep(&buf, ","))) { @@ -9903,11 +9929,18 @@ static int lcdshadow_write(char *buf) if (state >= 2 || state < 0) return -EINVAL;

- return lcdshadow_set(state); + mutex_lock(&lcdshadow_dev->lock); + res = lcdshadow_set_sw_state(lcdshadow_dev, state); + mutex_unlock(&lcdshadow_dev->lock); + + drm_privacy_screen_call_notifier_chain(lcdshadow_dev); + + return res; }

static struct ibm_struct lcdshadow_driver_data = { .name = "lcdshadow", + .exit = lcdshadow_exit, .resume = lcdshadow_resume, .read = lcdshadow_read, .write = lcdshadow_write, @@ -10717,6 +10750,20 @@ static void tpacpi_driver_event(const unsigned int hkey_event) if (!atomic_add_unless(&dytc_ignore_event, -1, 0)) dytc_profile_refresh(); } + + if (lcdshadow_dev && hkey_event == TP_HKEY_EV_PRIVACYGUARD_TOGGLE) { + enum drm_privacy_screen_status old_hw_state; + bool changed; + + mutex_lock(&lcdshadow_dev->lock); + old_hw_state = lcdshadow_dev->hw_state; + lcdshadow_get_hw_state(lcdshadow_dev); + changed = lcdshadow_dev->hw_state != old_hw_state; + mutex_unlock(&lcdshadow_dev->lock); + + if (changed) + drm_privacy_screen_call_notifier_chain(lcdshadow_dev); + } }

static void hotkey_driver_event(const unsigned int scancode)