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, f: "%s.%s=%s\n", driver_name, name, str_yes_no(v: 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, f: "%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, f: "%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, f: "%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, f: "%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(s: *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(objp: *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}
243

source code of linux/drivers/gpu/drm/i915/display/intel_display_params.c