/* * Copyright (c) 2016 Intel Corporation * * Permission to use, copy, modify, distribute, and sell this software and its * documentation for any purpose is hereby granted without fee, provided that * the above copyright notice appear in all copies and that both that copyright * notice and this permission notice appear in supporting documentation, and * that the name of the copyright holders not be used in advertising or * publicity pertaining to distribution of the software without specific, * written prior permission. The copyright holders make no representations * about the suitability of this software for any purpose. It is provided "as * is" without express or implied warranty. * * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE * OF THIS SOFTWARE. */ #include <linux/uaccess.h> #include <drm/drm_atomic.h> #include <drm/drm_color_mgmt.h> #include <drm/drm_crtc.h> #include <drm/drm_device.h> #include <drm/drm_drv.h> #include <drm/drm_print.h> #include "drm_crtc_internal.h" /** * DOC: overview * * Color management or color space adjustments is supported through a set of 5 * properties on the &drm_crtc object. They are set up by calling * drm_crtc_enable_color_mgmt(). * * "DEGAMMA_LUT”: * Blob property to set the degamma lookup table (LUT) mapping pixel data * from the framebuffer before it is given to the transformation matrix. * The data is interpreted as an array of &struct drm_color_lut elements. * Hardware might choose not to use the full precision of the LUT elements * nor use all the elements of the LUT (for example the hardware might * choose to interpolate between LUT[0] and LUT[4]). * * Setting this to NULL (blob property value set to 0) means a * linear/pass-thru gamma table should be used. This is generally the * driver boot-up state too. Drivers can access this blob through * &drm_crtc_state.degamma_lut. * * “DEGAMMA_LUT_SIZE”: * Unsinged range property to give the size of the lookup table to be set * on the DEGAMMA_LUT property (the size depends on the underlying * hardware). If drivers support multiple LUT sizes then they should * publish the largest size, and sub-sample smaller sized LUTs (e.g. for * split-gamma modes) appropriately. * * “CTM”: * Blob property to set the current transformation matrix (CTM) apply to * pixel data after the lookup through the degamma LUT and before the * lookup through the gamma LUT. The data is interpreted as a struct * &drm_color_ctm. * * Setting this to NULL (blob property value set to 0) means a * unit/pass-thru matrix should be used. This is generally the driver * boot-up state too. Drivers can access the blob for the color conversion * matrix through &drm_crtc_state.ctm. * * “GAMMA_LUT”: * Blob property to set the gamma lookup table (LUT) mapping pixel data * after the transformation matrix to data sent to the connector. The * data is interpreted as an array of &struct drm_color_lut elements. * Hardware might choose not to use the full precision of the LUT elements * nor use all the elements of the LUT (for example the hardware might * choose to interpolate between LUT[0] and LUT[4]). * * Setting this to NULL (blob property value set to 0) means a * linear/pass-thru gamma table should be used. This is generally the * driver boot-up state too. Drivers can access this blob through * &drm_crtc_state.gamma_lut. * * Note that for mostly historical reasons stemming from Xorg heritage, * this is also used to store the color map (also sometimes color lut, CLUT * or color palette) for indexed formats like DRM_FORMAT_C8. * * “GAMMA_LUT_SIZE”: * Unsigned range property to give the size of the lookup table to be set * on the GAMMA_LUT property (the size depends on the underlying hardware). * If drivers support multiple LUT sizes then they should publish the * largest size, and sub-sample smaller sized LUTs (e.g. for split-gamma * modes) appropriately. * * There is also support for a legacy gamma table, which is set up by calling * drm_mode_crtc_set_gamma_size(). The DRM core will then alias the legacy gamma * ramp with "GAMMA_LUT" or, if that is unavailable, "DEGAMMA_LUT". * * Support for different non RGB color encodings is controlled through * &drm_plane specific COLOR_ENCODING and COLOR_RANGE properties. They * are set up by calling drm_plane_create_color_properties(). * * "COLOR_ENCODING": * Optional plane enum property to support different non RGB * color encodings. The driver can provide a subset of standard * enum values supported by the DRM plane. * * "COLOR_RANGE": * Optional plane enum property to support different non RGB * color parameter ranges. The driver can provide a subset of * standard enum values supported by the DRM plane. */ /** * drm_color_ctm_s31_32_to_qm_n * * @user_input: input value * @m: number of integer bits, only support m <= 32, include the sign-bit * @n: number of fractional bits, only support n <= 32 * * Convert and clamp S31.32 sign-magnitude to Qm.n (signed 2's complement). * The sign-bit BIT(m+n-1) and above are 0 for positive value and 1 for negative * the range of value is [-2^(m-1), 2^(m-1) - 2^-n] * * For example * A Q3.12 format number: * - required bit: 3 + 12 = 15bits * - range: [-2^2, 2^2 - 2^−15] * * NOTE: the m can be zero if all bit_precision are used to present fractional * bits like Q0.32 */ u64 drm_color_ctm_s31_32_to_qm_n(u64 user_input, u32 m, u32 n) { … } EXPORT_SYMBOL(…); /** * drm_crtc_enable_color_mgmt - enable color management properties * @crtc: DRM CRTC * @degamma_lut_size: the size of the degamma lut (before CSC) * @has_ctm: whether to attach ctm_property for CSC matrix * @gamma_lut_size: the size of the gamma lut (after CSC) * * This function lets the driver enable the color correction * properties on a CRTC. This includes 3 degamma, csc and gamma * properties that userspace can set and 2 size properties to inform * the userspace of the lut sizes. Each of the properties are * optional. The gamma and degamma properties are only attached if * their size is not 0 and ctm_property is only attached if has_ctm is * true. */ void drm_crtc_enable_color_mgmt(struct drm_crtc *crtc, uint degamma_lut_size, bool has_ctm, uint gamma_lut_size) { … } EXPORT_SYMBOL(…); /** * drm_mode_crtc_set_gamma_size - set the gamma table size * @crtc: CRTC to set the gamma table size for * @gamma_size: size of the gamma table * * Drivers which support gamma tables should set this to the supported gamma * table size when initializing the CRTC. Currently the drm core only supports a * fixed gamma table size. * * Returns: * Zero on success, negative errno on failure. */ int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc, int gamma_size) { … } EXPORT_SYMBOL(…); /** * drm_crtc_supports_legacy_gamma - does the crtc support legacy gamma correction table * @crtc: CRTC object * * Returns true/false if the given crtc supports setting the legacy gamma * correction table. */ static bool drm_crtc_supports_legacy_gamma(struct drm_crtc *crtc) { … } /** * drm_crtc_legacy_gamma_set - set the legacy gamma correction table * @crtc: CRTC object * @red: red correction table * @green: green correction table * @blue: blue correction table * @size: size of the tables * @ctx: lock acquire context * * Implements support for legacy gamma correction table for drivers * that have set drm_crtc_funcs.gamma_set or that support color management * through the DEGAMMA_LUT/GAMMA_LUT properties. See * drm_crtc_enable_color_mgmt() and the containing chapter for * how the atomic color management and gamma tables work. * * This function sets the gamma using drm_crtc_funcs.gamma_set if set, or * alternatively using crtc color management properties. */ static int drm_crtc_legacy_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green, u16 *blue, u32 size, struct drm_modeset_acquire_ctx *ctx) { … } /** * drm_mode_gamma_set_ioctl - set the gamma table * @dev: DRM device * @data: ioctl data * @file_priv: DRM file info * * Set the gamma table of a CRTC to the one passed in by the user. Userspace can * inquire the required gamma table size through drm_mode_gamma_get_ioctl. * * Called by the user via ioctl. * * Returns: * Zero on success, negative errno on failure. */ int drm_mode_gamma_set_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { … } /** * drm_mode_gamma_get_ioctl - get the gamma table * @dev: DRM device * @data: ioctl data * @file_priv: DRM file info * * Copy the current gamma table into the storage provided. This also provides * the gamma table size the driver expects, which can be used to size the * allocated storage. * * Called by the user via ioctl. * * Returns: * Zero on success, negative errno on failure. */ int drm_mode_gamma_get_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { … } static const char * const color_encoding_name[] = …; static const char * const color_range_name[] = …; /** * drm_get_color_encoding_name - return a string for color encoding * @encoding: color encoding to compute name of * * In contrast to the other drm_get_*_name functions this one here returns a * const pointer and hence is threadsafe. */ const char *drm_get_color_encoding_name(enum drm_color_encoding encoding) { … } /** * drm_get_color_range_name - return a string for color range * @range: color range to compute name of * * In contrast to the other drm_get_*_name functions this one here returns a * const pointer and hence is threadsafe. */ const char *drm_get_color_range_name(enum drm_color_range range) { … } /** * drm_plane_create_color_properties - color encoding related plane properties * @plane: plane object * @supported_encodings: bitfield indicating supported color encodings * @supported_ranges: bitfileld indicating supported color ranges * @default_encoding: default color encoding * @default_range: default color range * * Create and attach plane specific COLOR_ENCODING and COLOR_RANGE * properties to @plane. The supported encodings and ranges should * be provided in supported_encodings and supported_ranges bitmasks. * Each bit set in the bitmask indicates that its number as enum * value is supported. */ int drm_plane_create_color_properties(struct drm_plane *plane, u32 supported_encodings, u32 supported_ranges, enum drm_color_encoding default_encoding, enum drm_color_range default_range) { … } EXPORT_SYMBOL(…); /** * drm_color_lut_check - check validity of lookup table * @lut: property blob containing LUT to check * @tests: bitmask of tests to run * * Helper to check whether a userspace-provided lookup table is valid and * satisfies hardware requirements. Drivers pass a bitmask indicating which of * the tests in &drm_color_lut_tests should be performed. * * Returns 0 on success, -EINVAL on failure. */ int drm_color_lut_check(const struct drm_property_blob *lut, u32 tests) { … } EXPORT_SYMBOL(…);
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