linux/drivers/gpu/drm/i915/display/intel_cmtg.h

/* SPDX-License-Identifier: MIT */
/*
 * Copyright (C) 2025 Intel Corporation
 */

#ifndef __INTEL_CMTG_H__
#define __INTEL_CMTG_H__

struct intel_display;

void intel_cmtg_sanitize(struct intel_display *display);

#endif /* __INTEL_CMTG_H__ */
drm/i915/cmtg: Disable the CMTG The CMTG is a timing generator that runs in parallel with transcoders timing generators and can be used as a reference for synchronization. We have observed that we are inheriting from GOP a display configuration with the CMTG enabled. Because our driver doesn't currently implement any CMTG sequences, the CMTG ends up still enabled after our driver takes over. We need to make sure that the CMTG is not enabled if we are not going to use it. For that, let's add a partial implementation in our driver that only cares about disabling the CMTG if it was found enabled during initial hardware readout. In the future, we can also implement sequences for using the CMTG if that becomes a needed feature. For now, we only deal with cases when it is possible to disable the CMTG without requiring a modeset. For earlier display versions, we simply skip if we find the CMTG enabled and we can't disable it without a proper modeset. In the future, we need to properly handle that case. v2: - DG2 does not have the CMTG. Update HAS_CMTG() accordingly. - Update logic to force disabling of CMTG only for initial commit. v3: - Add missing changes for v2 that were staged but not committed. v4: - Avoid if/else duplication in intel_cmtg_dump_state() by using "n/a" for CMTG B enabled/disabled string for platforms without it. (Jani) - Prefer intel_cmtg_readout_hw_state() over intel_cmtg_readout_state(). (Jani) - Use display struct instead of i915 as first parameter for TRANS_DDI_FUNC_CTL2(). (Jani) - Fewer continuation lines in variable declaration/initialization for better readability. (Jani) - Coding style improvements. (Jani) - Use drm_dbg_kms() instead of drm_info() for logging the disabling of the CMTG. - Make struct intel_cmtg_state entirely private to intel_cmtg.c. v5: - Do the disable sequence as part of the sanitization step after hardware readout instead of initial modeset commit. (Jani) - Adapt to commit 15133582465f ("drm/i915/display: convert global state to struct intel_display") by using a display struct instead of i915 as argument for intel_atomic_global_obj_init(). v6: - Do not track CMTG state as a global state. (Ville) - Simplify the driver logic by only disabling the CMTG only on cases when a modeset is not required. (Ville) v7: - Remove the call to drm_WARN_ON() when checking intel_cmtg_disable_requires_modeset() and use a FIXME in the comment instead. - Remove the !HAS_CMTG() guard from intel_cmtg_get_config(), which is static and its caller is already protected by that same condition. - Also take the opportunity to put some Bspec references in the commit trailers section. v8: - Use HAS_TRANSCODER() instead of intel_crtc_for_pipe(). (Ville) - Ensure transcoder power well is enabled before reading TRANS_DDI_FUNC_CTL2. (Ville) Bspec: 68915, 49262 Cc: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250124173956.46534-1-gustavo.sousa@intel.com 2025-01-24 14:38:14 -03:00			`/* SPDX-License-Identifier: MIT */`
			`/*`
			`* Copyright (C) 2025 Intel Corporation`
			`*/`

			`#ifndef __INTEL_CMTG_H__`
			`#define __INTEL_CMTG_H__`

			`struct intel_display;`

			`void intel_cmtg_sanitize(struct intel_display *display);`

			`#endif /* __INTEL_CMTG_H__ */`