intel_display_params.c

  1// SPDX-License-Identifier: MIT
  2/*
  3 * Copyright © 2023 Intel Corporation
  4 */
  5
  6#include <linux/moduleparam.h>
  7#include <linux/slab.h>
  8#include <linux/string_choices.h>
  9
 10#include <drm/drm_print.h>
 11
 12#include "intel_display_params.h"
 13
 14#define intel_display_param_named(name, T, perm, desc) \
 15	module_param_named(name, intel_display_modparams.name, T, perm); \
 16	MODULE_PARM_DESC(name, desc)
 17#define intel_display_param_named_unsafe(name, T, perm, desc) \
 18	module_param_named_unsafe(name, intel_display_modparams.name, T, perm); \
 19	MODULE_PARM_DESC(name, desc)
 20
 21static struct intel_display_params intel_display_modparams __read_mostly = {
 22#define MEMBER(T, member, value, ...) .member = (value),
 23	INTEL_DISPLAY_PARAMS_FOR_EACH(MEMBER)
 24#undef MEMBER
 25};
 26/*
 27 * Note: As a rule, keep module parameter sysfs permissions read-only
 28 * 0400. Runtime changes are only supported through i915 debugfs.
 29 *
 30 * For any exceptions requiring write access and runtime changes through module
 31 * parameter sysfs, prevent debugfs file creation by setting the parameter's
 32 * debugfs mode to 0.
 33 */
 34
 35intel_display_param_named_unsafe(dmc_firmware_path, charp, 0400,
 36	"DMC firmware path to use instead of the default one. "
 37	"Use /dev/null to disable DMC and runtime PM.");
 38
 39intel_display_param_named_unsafe(vbt_firmware, charp, 0400,
 40	"Load VBT from specified file under /lib/firmware");
 41
 42intel_display_param_named_unsafe(lvds_channel_mode, int, 0400,
 43	 "Specify LVDS channel mode "
 44	 "(0=probe BIOS [default], 1=single-channel, 2=dual-channel)");
 45
 46intel_display_param_named_unsafe(panel_use_ssc, int, 0400,
 47	"Use Spread Spectrum Clock with panels [LVDS/eDP] "
 48	"(default: auto from VBT)");
 49
 50intel_display_param_named_unsafe(vbt_sdvo_panel_type, int, 0400,
 51	"Override/Ignore selection of SDVO panel mode in the VBT "
 52	"(-2=ignore, -1=auto [default], index in VBT BIOS table)");
 53
 54intel_display_param_named_unsafe(enable_dc, int, 0400,
 55	"Enable power-saving display C-states. "
 56	"(-1=auto [default]; 0=disable; 1=up to DC5; 2=up to DC6; "
 57	"3=up to DC5 with DC3CO; 4=up to DC6 with DC3CO)");
 58
 59intel_display_param_named_unsafe(enable_dpt, bool, 0400,
 60	"Enable display page table (DPT) (default: true)");
 61
 62intel_display_param_named_unsafe(enable_dsb, bool, 0400,
 63	"Enable display state buffer (DSB) (default: true)");
 64
 65intel_display_param_named_unsafe(enable_flipq, bool, 0400,
 66	"Enable DMC flip queue (default: false)");
 67
 68intel_display_param_named_unsafe(enable_sagv, bool, 0400,
 69	"Enable system agent voltage/frequency scaling (SAGV) (default: true)");
 70
 71intel_display_param_named_unsafe(disable_power_well, int, 0400,
 72	"Disable display power wells when possible "
 73	"(-1=auto [default], 0=power wells always on, 1=power wells disabled when possible)");
 74
 75intel_display_param_named_unsafe(enable_ips, bool, 0400, "Enable IPS (default: true)");
 76
 77intel_display_param_named_unsafe(invert_brightness, int, 0400,
 78	"Invert backlight brightness "
 79	"(-1 force normal, 0 machine defaults, 1 force inversion), please "
 80	"report PCI device ID, subsystem vendor and subsystem device ID "
 81	"to dri-devel@lists.freedesktop.org, if your machine needs it. "
 82	"It will then be included in an upcoming module version.");
 83
 84/* WA to get away with the default setting in VBT for early platforms.Will be removed */
 85intel_display_param_named_unsafe(edp_vswing, int, 0400,
 86	"Ignore/Override vswing pre-emph table selection from VBT "
 87	"(0=use value from vbt [default], 1=low power swing(200mV),"
 88	"2=default swing(400mV))");
 89
 90intel_display_param_named(enable_dpcd_backlight, int, 0400,
 91	"Enable support for DPCD backlight control"
 92	"(-1=use per-VBT LFP backlight type setting [default], 0=disabled, 1=enable, 2=force VESA interface, 3=force Intel interface)");
 93
 94intel_display_param_named_unsafe(load_detect_test, bool, 0400,
 95	"Force-enable the VGA load detect code for testing (default:false). "
 96	"For developers only.");
 97
 98intel_display_param_named_unsafe(force_reset_modeset_test, bool, 0400,
 99	"Force a modeset during gpu reset for testing (default:false). "
100	"For developers only.");
101
102intel_display_param_named(disable_display, bool, 0400,
103	"Disable display (default: false)");
104
105intel_display_param_named(verbose_state_checks, bool, 0400,
106	"Enable verbose logs (ie. WARN_ON()) in case of unexpected hw state conditions.");
107
108intel_display_param_named_unsafe(nuclear_pageflip, bool, 0400,
109	"Force enable atomic functionality on platforms that don't have full support yet.");
110
111intel_display_param_named_unsafe(enable_dp_mst, bool, 0400,
112	"Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");
113
114intel_display_param_named_unsafe(enable_fbc, int, 0400,
115	"Enable frame buffer compression for power savings "
116	"(default: -1 (use per-chip default))");
117
118intel_display_param_named_unsafe(enable_psr, int, 0400,
119	"Enable PSR "
120	"(0=disabled, 1=enable up to PSR1, 2=enable up to PSR2) "
121	"Default: -1 (use per-chip default)");
122
123intel_display_param_named_unsafe(enable_panel_replay, int, 0400,
124	"Enable Panel Replay (0=disabled, 1=enabled). Default: -1 (use per-chip default)");
125
126intel_display_param_named(psr_safest_params, bool, 0400,
127	"Replace PSR VBT parameters by the safest and not optimal ones. This "
128	"is helpful to detect if PSR issues are related to bad values set in "
129	" VBT. (0=use VBT parameters, 1=use safest parameters)"
130	"Default: 0");
131
132intel_display_param_named_unsafe(enable_psr2_sel_fetch, bool, 0400,
133	"Enable PSR2 and Panel Replay selective fetch "
134	"(0=disabled, 1=enabled) "
135	"Default: 1");
136
137intel_display_param_named_unsafe(enable_dmc_wl, int, 0400,
138	"Enable DMC wakelock "
139	"(-1=use per-chip default, 0=disabled, 1=enabled, 2=match any register, 3=always locked) "
140	"Default: -1");
141
142__maybe_unused
143static void _param_print_bool(struct drm_printer *p, const char *driver_name,
144			      const char *name, bool val)
145{
146	drm_printf(p, "%s.%s=%s\n", driver_name, name, str_yes_no(val));
147}
148
149__maybe_unused
150static void _param_print_int(struct drm_printer *p, const char *driver_name,
151			     const char *name, int val)
152{
153	drm_printf(p, "%s.%s=%d\n", driver_name, name, val);
154}
155
156__maybe_unused
157static void _param_print_uint(struct drm_printer *p, const char *driver_name,
158			      const char *name, unsigned int val)
159{
160	drm_printf(p, "%s.%s=%u\n", driver_name, name, val);
161}
162
163__maybe_unused
164static void _param_print_ulong(struct drm_printer *p, const char *driver_name,
165			       const char *name, unsigned long val)
166{
167	drm_printf(p, "%s.%s=%lu\n", driver_name, name, val);
168}
169
170__maybe_unused
171static void _param_print_charp(struct drm_printer *p, const char *driver_name,
172			       const char *name, const char *val)
173{
174	drm_printf(p, "%s.%s=%s\n", driver_name, name, val);
175}
176
177#define _param_print(p, driver_name, name, val)			\
178	_Generic(val,						\
179		 bool : _param_print_bool,			\
180		 int : _param_print_int,			\
181		 unsigned int : _param_print_uint,		\
182		 unsigned long : _param_print_ulong,		\
183		 char * : _param_print_charp)(p, driver_name, name, val)
184
185/**
186 * intel_display_params_dump - dump intel display modparams
187 * @params: display params
188 * @driver_name: driver name to use for printing
189 * @p: the &drm_printer
190 *
191 * Pretty printer for i915 modparams.
192 */
193void intel_display_params_dump(const struct intel_display_params *params,
194			       const char *driver_name, struct drm_printer *p)
195{
196#define PRINT(T, x, ...) _param_print(p, driver_name, #x, params->x);
197	INTEL_DISPLAY_PARAMS_FOR_EACH(PRINT);
198#undef PRINT
199}
200
201__maybe_unused static void _param_dup_charp(char **valp)
202{
203	*valp = kstrdup(*valp ? *valp : "", GFP_ATOMIC);
204}
205
206__maybe_unused static void _param_nop(void *valp)
207{
208}
209
210#define _param_dup(valp)				\
211	_Generic(valp,					\
212		 char ** : _param_dup_charp,		\
213		 default : _param_nop)			\
214		(valp)
215
216void intel_display_params_copy(struct intel_display_params *dest)
217{
218	*dest = intel_display_modparams;
219#define DUP(T, x, ...) _param_dup(&dest->x);
220	INTEL_DISPLAY_PARAMS_FOR_EACH(DUP);
221#undef DUP
222}
223
224__maybe_unused static void _param_free_charp(char **valp)
225{
226	kfree(*valp);
227	*valp = NULL;
228}
229
230#define _param_free(valp)				\
231	_Generic(valp,					\
232		 char ** : _param_free_charp,		\
233		 default : _param_nop)			\
234		(valp)
235
236/* free the allocated members, *not* the passed in params itself */
237void intel_display_params_free(struct intel_display_params *params)
238{
239#define FREE(T, x, ...) _param_free(&params->x);
240	INTEL_DISPLAY_PARAMS_FOR_EACH(FREE);
241#undef FREE
242}