On Tue, Oct 22, 2019 at 05:12:06PM -0700, Rajat Jain wrote: > Certain laptops now come with panels that have integrated privacy > screens on them. This patch adds support for such panels by adding > a privacy-screen property to the drm_connector for the panel, that > the userspace can then use to control and check the status. The idea > was discussed here: > > https://lkml.org/lkml/2019/10/1/786 > > ACPI methods are used to identify, query and control privacy screen: > > * Identifying an ACPI object corresponding to the panel: The patch > follows ACPI Spec 6.3 (available at > https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf). > Pages 1119 - 1123 describe what I believe, is a standard way of > identifying / addressing "display panels" in the ACPI tables, thus > allowing kernel to attach ACPI nodes to the panel. IMHO, this ability > to identify and attach ACPI nodes to drm connectors may be useful for > reasons other privacy-screens, in future. > > * Identifying the presence of privacy screen, and controlling it, is done > via ACPI _DSM methods. > > Currently, this is done only for the Intel display ports. But in future, > this can be done for any other ports if the hardware becomes available > (e.g. external monitors supporting integrated privacy screens?). > > Also, this code can be extended in future to support non-ACPI methods > (e.g. using a kernel GPIO driver to toggle a gpio that controls the > privacy-screen). > > Signed-off-by: Rajat Jain <rajatja@xxxxxxxxxx> New properties need property docs in the relevant section: https://dri.freedesktop.org/docs/drm/gpu/drm-kms.html#kms-properties $ make htmldocs for building them locally. Cheers, Daniel > --- > drivers/gpu/drm/Makefile | 1 + > drivers/gpu/drm/drm_atomic_uapi.c | 5 + > drivers/gpu/drm/drm_connector.c | 38 +++++ > drivers/gpu/drm/drm_privacy_screen.c | 176 ++++++++++++++++++++++++ > drivers/gpu/drm/i915/display/intel_dp.c | 3 + > include/drm/drm_connector.h | 18 +++ > include/drm/drm_mode_config.h | 7 + > include/drm/drm_privacy_screen.h | 33 +++++ > 8 files changed, 281 insertions(+) > create mode 100644 drivers/gpu/drm/drm_privacy_screen.c > create mode 100644 include/drm/drm_privacy_screen.h > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile > index 82ff826b33cc..e1fc33d69bb7 100644 > --- a/drivers/gpu/drm/Makefile > +++ b/drivers/gpu/drm/Makefile > @@ -19,6 +19,7 @@ drm-y := drm_auth.o drm_cache.o \ > drm_syncobj.o drm_lease.o drm_writeback.o drm_client.o \ > drm_client_modeset.o drm_atomic_uapi.o drm_hdcp.o > > +drm-$(CONFIG_ACPI) += drm_privacy_screen.o > drm-$(CONFIG_DRM_LEGACY) += drm_legacy_misc.o drm_bufs.o drm_context.o drm_dma.o drm_scatter.o drm_lock.o > drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o > drm-$(CONFIG_DRM_VM) += drm_vm.o > diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c > index 7a26bfb5329c..44131165e4ea 100644 > --- a/drivers/gpu/drm/drm_atomic_uapi.c > +++ b/drivers/gpu/drm/drm_atomic_uapi.c > @@ -30,6 +30,7 @@ > #include <drm/drm_atomic.h> > #include <drm/drm_print.h> > #include <drm/drm_drv.h> > +#include <drm/drm_privacy_screen.h> > #include <drm/drm_writeback.h> > #include <drm/drm_vblank.h> > > @@ -766,6 +767,8 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector, > fence_ptr); > } else if (property == connector->max_bpc_property) { > state->max_requested_bpc = val; > + } else if (property == config->privacy_screen_property) { > + drm_privacy_screen_set_val(connector, val); > } else if (connector->funcs->atomic_set_property) { > return connector->funcs->atomic_set_property(connector, > state, property, val); > @@ -842,6 +845,8 @@ drm_atomic_connector_get_property(struct drm_connector *connector, > *val = 0; > } else if (property == connector->max_bpc_property) { > *val = state->max_requested_bpc; > + } else if (property == config->privacy_screen_property) { > + *val = drm_privacy_screen_get_val(connector); > } else if (connector->funcs->atomic_get_property) { > return connector->funcs->atomic_get_property(connector, > state, property, val); > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c > index 4c766624b20d..a31e0382132b 100644 > --- a/drivers/gpu/drm/drm_connector.c > +++ b/drivers/gpu/drm/drm_connector.c > @@ -821,6 +821,11 @@ static const struct drm_prop_enum_list drm_panel_orientation_enum_list[] = { > { DRM_MODE_PANEL_ORIENTATION_RIGHT_UP, "Right Side Up" }, > }; > > +static const struct drm_prop_enum_list drm_privacy_screen_enum_list[] = { > + { DRM_PRIVACY_SCREEN_DISABLED, "Disabled" }, > + { DRM_PRIVACY_SCREEN_ENABLED, "Enabled" }, > +}; > + > static const struct drm_prop_enum_list drm_dvi_i_select_enum_list[] = { > { DRM_MODE_SUBCONNECTOR_Automatic, "Automatic" }, /* DVI-I and TV-out */ > { DRM_MODE_SUBCONNECTOR_DVID, "DVI-D" }, /* DVI-I */ > @@ -2253,6 +2258,39 @@ static void drm_tile_group_free(struct kref *kref) > kfree(tg); > } > > +/** > + * drm_connector_init_privacy_screen_property - > + * create and attach the connecter's privacy-screen property. > + * @connector: connector for which to init the privacy-screen property. > + * > + * This function creates and attaches the "privacy-screen" property to the > + * connector. Initial state of privacy-screen is set to disabled. > + * > + * Returns: > + * Zero on success, negative errno on failure. > + */ > +int drm_connector_init_privacy_screen_property(struct drm_connector *connector) > +{ > + struct drm_device *dev = connector->dev; > + struct drm_property *prop; > + > + prop = dev->mode_config.privacy_screen_property; > + if (!prop) { > + prop = drm_property_create_enum(dev, DRM_MODE_PROP_ENUM, > + "privacy-screen", drm_privacy_screen_enum_list, > + ARRAY_SIZE(drm_privacy_screen_enum_list)); > + if (!prop) > + return -ENOMEM; > + > + dev->mode_config.privacy_screen_property = prop; > + } > + > + drm_object_attach_property(&connector->base, prop, > + DRM_PRIVACY_SCREEN_DISABLED); > + return 0; > +} > +EXPORT_SYMBOL(drm_connector_init_privacy_screen_property); > + > /** > * drm_mode_put_tile_group - drop a reference to a tile group. > * @dev: DRM device > diff --git a/drivers/gpu/drm/drm_privacy_screen.c b/drivers/gpu/drm/drm_privacy_screen.c > new file mode 100644 > index 000000000000..1d68e8aa6c5f > --- /dev/null > +++ b/drivers/gpu/drm/drm_privacy_screen.c > @@ -0,0 +1,176 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * DRM privacy Screen code > + * > + * Copyright © 2019 Google Inc. > + */ > + > +#include <linux/acpi.h> > +#include <linux/pci.h> > + > +#include <drm/drm_connector.h> > +#include <drm/drm_device.h> > +#include <drm/drm_print.h> > + > +#define DRM_CONN_DSM_REVID 1 > + > +#define DRM_CONN_DSM_FN_PRIVACY_GET_STATUS 1 > +#define DRM_CONN_DSM_FN_PRIVACY_ENABLE 2 > +#define DRM_CONN_DSM_FN_PRIVACY_DISABLE 3 > + > +static const guid_t drm_conn_dsm_guid = > + GUID_INIT(0xC7033113, 0x8720, 0x4CEB, > + 0x90, 0x90, 0x9D, 0x52, 0xB3, 0xE5, 0x2D, 0x73); > + > +/* > + * Makes _DSM call to set privacy screen status or get privacy screen. Return > + * value matters only for PRIVACY_GET_STATUS case. Returns 0 if disabled, 1 if > + * enabled. > + */ > +static int acpi_privacy_screen_call_dsm(acpi_handle conn_handle, u64 func) > +{ > + union acpi_object *obj; > + int ret = 0; > + > + obj = acpi_evaluate_dsm(conn_handle, &drm_conn_dsm_guid, > + DRM_CONN_DSM_REVID, func, NULL); > + if (!obj) { > + DRM_DEBUG_DRIVER("failed to evaluate _DSM for fn %llx\n", func); > + /* Can't do much. For get_val, assume privacy_screen disabled */ > + goto done; > + } > + > + if (func == DRM_CONN_DSM_FN_PRIVACY_GET_STATUS && > + obj->type == ACPI_TYPE_INTEGER) > + ret = !!obj->integer.value; > +done: > + ACPI_FREE(obj); > + return ret; > +} > + > +void drm_privacy_screen_set_val(struct drm_connector *connector, > + enum drm_privacy_screen val) > +{ > + acpi_handle acpi_handle = connector->privacy_screen_handle; > + > + if (!acpi_handle) > + return; > + > + if (val == DRM_PRIVACY_SCREEN_DISABLED) > + acpi_privacy_screen_call_dsm(acpi_handle, > + DRM_CONN_DSM_FN_PRIVACY_DISABLE); > + else if (val == DRM_PRIVACY_SCREEN_ENABLED) > + acpi_privacy_screen_call_dsm(acpi_handle, > + DRM_CONN_DSM_FN_PRIVACY_ENABLE); > +} > + > +enum drm_privacy_screen drm_privacy_screen_get_val(struct drm_connector > + *connector) > +{ > + acpi_handle acpi_handle = connector->privacy_screen_handle; > + > + if (acpi_handle && > + acpi_privacy_screen_call_dsm(acpi_handle, > + DRM_CONN_DSM_FN_PRIVACY_GET_STATUS)) > + return DRM_PRIVACY_SCREEN_ENABLED; > + > + return DRM_PRIVACY_SCREEN_DISABLED; > +} > + > +/* > + * See ACPI Spec v6.3, Table B-2, "Display Type" for details. > + * In short, these macros define the base _ADR values for ACPI nodes > + */ > +#define ACPI_BASE_ADR_FOR_OTHERS (0ULL << 8) > +#define ACPI_BASE_ADR_FOR_VGA (1ULL << 8) > +#define ACPI_BASE_ADR_FOR_TV (2ULL << 8) > +#define ACPI_BASE_ADR_FOR_EXT_MON (3ULL << 8) > +#define ACPI_BASE_ADR_FOR_INTEGRATED (4ULL << 8) > + > +#define ACPI_DEVICE_ID_SCHEME (1ULL << 31) > +#define ACPI_FIRMWARE_CAN_DETECT (1ULL << 16) > + > +/* > + * Ref: ACPI Spec 6.3 > + * https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf > + * Pages 1119 - 1123 describe, what I believe, a standard way of > + * identifying / addressing "display panels" in the ACPI. Thus it provides > + * a way for the ACPI to define devices for the display panels attached > + * to the system. It thus provides a way for the BIOS to export any panel > + * specific properties to the system via ACPI (like device trees). > + * > + * The following function looks up the ACPI node for a connector and links > + * to it. Technically it is independent from the privacy_screen code, and > + * ideally may be called for all connectors. It is generally a good idea to > + * be able to attach an ACPI node to describe anything if needed. (This can > + * help in future for other panel specific features maybe). However, it > + * needs a "port index" which I believe is the index within a particular > + * type of port (Ref to the pages of spec mentioned above). This port index > + * unfortunately is not available in DRM code, so currently its call is > + * originated from i915 driver. > + */ > +static int drm_connector_attach_acpi_node(struct drm_connector *connector, > + u8 port_index) > +{ > + struct device *dev = &connector->dev->pdev->dev; > + struct acpi_device *conn_dev; > + u64 conn_addr; > + > + /* > + * Determine what _ADR to look for, depending on device type and > + * port number. Potentially we only care about the > + * eDP / integrated displays? > + */ > + switch (connector->connector_type) { > + case DRM_MODE_CONNECTOR_eDP: > + conn_addr = ACPI_BASE_ADR_FOR_INTEGRATED + port_index; > + break; > + case DRM_MODE_CONNECTOR_VGA: > + conn_addr = ACPI_BASE_ADR_FOR_VGA + port_index; > + break; > + case DRM_MODE_CONNECTOR_TV: > + conn_addr = ACPI_BASE_ADR_FOR_TV + port_index; > + break; > + case DRM_MODE_CONNECTOR_DisplayPort: > + conn_addr = ACPI_BASE_ADR_FOR_EXT_MON + port_index; > + break; > + default: > + return -ENOTSUPP; > + } > + > + conn_addr |= ACPI_DEVICE_ID_SCHEME; > + conn_addr |= ACPI_FIRMWARE_CAN_DETECT; > + > + DRM_DEV_DEBUG(dev, "%s: Finding drm_connector ACPI node at _ADR=%llX\n", > + __func__, conn_addr); > + > + /* Look up the connector device, under the PCI device */ > + conn_dev = acpi_find_child_device(ACPI_COMPANION(dev), > + conn_addr, false); > + if (!conn_dev) > + return -ENODEV; > + > + connector->privacy_screen_handle = conn_dev->handle; > + return 0; > +} > + > +bool drm_privacy_screen_present(struct drm_connector *connector, u8 port_index) > +{ > + acpi_handle handle; > + > + if (drm_connector_attach_acpi_node(connector, port_index)) > + return false; > + > + handle = connector->privacy_screen_handle; > + if (!acpi_check_dsm(handle, &drm_conn_dsm_guid, > + DRM_CONN_DSM_REVID, > + 1 << DRM_CONN_DSM_FN_PRIVACY_GET_STATUS | > + 1 << DRM_CONN_DSM_FN_PRIVACY_ENABLE | > + 1 << DRM_CONN_DSM_FN_PRIVACY_DISABLE)) { > + DRM_WARN("%s: Odd, connector ACPI node but no privacy scrn?\n", > + connector->dev->dev); > + return false; > + } > + DRM_DEV_INFO(connector->dev->dev, "supports privacy screen\n"); > + return true; > +} > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > index 57e9f0ba331b..3ff3962d27db 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > @@ -39,6 +39,7 @@ > #include <drm/drm_dp_helper.h> > #include <drm/drm_edid.h> > #include <drm/drm_hdcp.h> > +#include <drm/drm_privacy_screen.h> > #include <drm/drm_probe_helper.h> > #include <drm/i915_drm.h> > > @@ -6354,6 +6355,8 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect > > connector->state->scaling_mode = DRM_MODE_SCALE_ASPECT; > > + if (drm_privacy_screen_present(connector, port - PORT_A)) > + drm_connector_init_privacy_screen_property(connector); > } > } > > diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h > index 681cb590f952..63b8318bd68c 100644 > --- a/include/drm/drm_connector.h > +++ b/include/drm/drm_connector.h > @@ -225,6 +225,20 @@ enum drm_link_status { > DRM_LINK_STATUS_BAD = DRM_MODE_LINK_STATUS_BAD, > }; > > +/** > + * enum drm_privacy_screen - privacy_screen status > + * > + * This enum is used to track and control the state of the privacy screen. > + * There are no separate #defines for the uapi! > + * > + * @DRM_PRIVACY_SCREEN_DISABLED: The privacy-screen on the panel is disabled > + * @DRM_PRIVACY_SCREEN_ENABLED: The privacy-screen on the panel is enabled > + */ > +enum drm_privacy_screen { > + DRM_PRIVACY_SCREEN_DISABLED = 0, > + DRM_PRIVACY_SCREEN_ENABLED = 1, > +}; > + > /** > * enum drm_panel_orientation - panel_orientation info for &drm_display_info > * > @@ -1410,6 +1424,9 @@ struct drm_connector { > > /** @hdr_sink_metadata: HDR Metadata Information read from sink */ > struct hdr_sink_metadata hdr_sink_metadata; > + > + /* Handle used by privacy screen code */ > + void *privacy_screen_handle; > }; > > #define obj_to_connector(x) container_of(x, struct drm_connector, base) > @@ -1543,6 +1560,7 @@ int drm_connector_init_panel_orientation_property( > struct drm_connector *connector, int width, int height); > int drm_connector_attach_max_bpc_property(struct drm_connector *connector, > int min, int max); > +int drm_connector_init_privacy_screen_property(struct drm_connector *connector); > > /** > * struct drm_tile_group - Tile group metadata > diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h > index 3bcbe30339f0..6d5d23da90d4 100644 > --- a/include/drm/drm_mode_config.h > +++ b/include/drm/drm_mode_config.h > @@ -813,6 +813,13 @@ struct drm_mode_config { > */ > struct drm_property *panel_orientation_property; > > + /** > + * @privacy_screen_property: Optional connector property to indicate > + * and control the state (enabled / disabled) of privacy-screen on the > + * panel, if present. > + */ > + struct drm_property *privacy_screen_property; > + > /** > * @writeback_fb_id_property: Property for writeback connectors, storing > * the ID of the output framebuffer. > diff --git a/include/drm/drm_privacy_screen.h b/include/drm/drm_privacy_screen.h > new file mode 100644 > index 000000000000..c589bbc47656 > --- /dev/null > +++ b/include/drm/drm_privacy_screen.h > @@ -0,0 +1,33 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * Copyright © 2019 Google Inc. > + */ > + > +#ifndef __DRM_PRIVACY_SCREEN_H__ > +#define __DRM_PRIVACY_SCREEN_H__ > + > +#ifdef CONFIG_ACPI > +bool drm_privacy_screen_present(struct drm_connector *connector, u8 port); > +void drm_privacy_screen_set_val(struct drm_connector *connector, > + enum drm_privacy_screen val); > +enum drm_privacy_screen drm_privacy_screen_get_val(struct drm_connector > + *connector); > +#else > +static inline bool drm_privacy_screen_present(struct drm_connector *connector, > + u8 port) > +{ > + return false; > +} > + > +void drm_privacy_screen_set_val(struct drm_connector *connector, > + enum drm_privacy_screen val) > +{ } > + > +enum drm_privacy_screen drm_privacy_screen_get_val( > + struct drm_connector *connector) > +{ > + return DRM_PRIVACY_SCREEN_DISABLED; > +} > +#endif /* CONFIG_ACPI */ > + > +#endif /* __DRM_PRIVACY_SCREEN_H__ */ > -- > 2.23.0.866.gb869b98d4c-goog > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
