1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2023 Intel Corporation
4 */
5
6#include "intel_display_params.h"
7#include "i915_drv.h"
8
9#define intel_display_param_named(name, T, perm, desc) \
10 module_param_named(name, intel_display_modparams.name, T, perm); \
11 MODULE_PARM_DESC(name, desc)
12#define intel_display_param_named_unsafe(name, T, perm, desc) \
13 module_param_named_unsafe(name, intel_display_modparams.name, T, perm); \
14 MODULE_PARM_DESC(name, desc)
15
16static struct intel_display_params intel_display_modparams __read_mostly = {
17#define MEMBER(T, member, value, ...) .member = (value),
18 INTEL_DISPLAY_PARAMS_FOR_EACH(MEMBER)
19#undef MEMBER
20};
21/*
22 * Note: As a rule, keep module parameter sysfs permissions read-only
23 * 0400. Runtime changes are only supported through i915 debugfs.
24 *
25 * For any exceptions requiring write access and runtime changes through module
26 * parameter sysfs, prevent debugfs file creation by setting the parameter's
27 * debugfs mode to 0.
28 */
29
30intel_display_param_named_unsafe(vbt_firmware, charp, 0400,
31 "Load VBT from specified file under /lib/firmware");
32
33intel_display_param_named_unsafe(lvds_channel_mode, int, 0400,
34 "Specify LVDS channel mode "
35 "(0=probe BIOS [default], 1=single-channel, 2=dual-channel)");
36
37intel_display_param_named_unsafe(panel_use_ssc, int, 0400,
38 "Use Spread Spectrum Clock with panels [LVDS/eDP] "
39 "(default: auto from VBT)");
40
41intel_display_param_named_unsafe(vbt_sdvo_panel_type, int, 0400,
42 "Override/Ignore selection of SDVO panel mode in the VBT "
43 "(-2=ignore, -1=auto [default], index in VBT BIOS table)");
44
45intel_display_param_named_unsafe(enable_dc, int, 0400,
46 "Enable power-saving display C-states. "
47 "(-1=auto [default]; 0=disable; 1=up to DC5; 2=up to DC6; "
48 "3=up to DC5 with DC3CO; 4=up to DC6 with DC3CO)");
49
50intel_display_param_named_unsafe(enable_dpt, bool, 0400,
51 "Enable display page table (DPT) (default: true)");
52
53intel_display_param_named_unsafe(enable_sagv, bool, 0400,
54 "Enable system agent voltage/frequency scaling (SAGV) (default: true)");
55
56intel_display_param_named_unsafe(disable_power_well, int, 0400,
57 "Disable display power wells when possible "
58 "(-1=auto [default], 0=power wells always on, 1=power wells disabled when possible)");
59
60intel_display_param_named_unsafe(enable_ips, bool, 0400, "Enable IPS (default: true)");
61
62intel_display_param_named_unsafe(invert_brightness, int, 0400,
63 "Invert backlight brightness "
64 "(-1 force normal, 0 machine defaults, 1 force inversion), please "
65 "report PCI device ID, subsystem vendor and subsystem device ID "
66 "to dri-devel@lists.freedesktop.org, if your machine needs it. "
67 "It will then be included in an upcoming module version.");
68
69/* WA to get away with the default setting in VBT for early platforms.Will be removed */
70intel_display_param_named_unsafe(edp_vswing, int, 0400,
71 "Ignore/Override vswing pre-emph table selection from VBT "
72 "(0=use value from vbt [default], 1=low power swing(200mV),"
73 "2=default swing(400mV))");
74
75intel_display_param_named(enable_dpcd_backlight, int, 0400,
76 "Enable support for DPCD backlight control"
77 "(-1=use per-VBT LFP backlight type setting [default], 0=disabled, 1=enable, 2=force VESA interface, 3=force Intel interface)");
78
79intel_display_param_named_unsafe(load_detect_test, bool, 0400,
80 "Force-enable the VGA load detect code for testing (default:false). "
81 "For developers only.");
82
83intel_display_param_named_unsafe(force_reset_modeset_test, bool, 0400,
84 "Force a modeset during gpu reset for testing (default:false). "
85 "For developers only.");
86
87intel_display_param_named(disable_display, bool, 0400,
88 "Disable display (default: false)");
89
90intel_display_param_named(verbose_state_checks, bool, 0400,
91 "Enable verbose logs (ie. WARN_ON()) in case of unexpected hw state conditions.");
92
93intel_display_param_named_unsafe(nuclear_pageflip, bool, 0400,
94 "Force enable atomic functionality on platforms that don't have full support yet.");
95
96intel_display_param_named_unsafe(enable_dp_mst, bool, 0400,
97 "Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");
98
99intel_display_param_named_unsafe(enable_fbc, int, 0400,
100 "Enable frame buffer compression for power savings "
101 "(default: -1 (use per-chip default))");
102
103intel_display_param_named_unsafe(enable_psr, int, 0400,
104 "Enable PSR "
105 "(0=disabled, 1=enable up to PSR1, 2=enable up to PSR2) "
106 "Default: -1 (use per-chip default)");
107
108intel_display_param_named(psr_safest_params, bool, 0400,
109 "Replace PSR VBT parameters by the safest and not optimal ones. This "
110 "is helpful to detect if PSR issues are related to bad values set in "
111 " VBT. (0=use VBT parameters, 1=use safest parameters)"
112 "Default: 0");
113
114intel_display_param_named_unsafe(enable_psr2_sel_fetch, bool, 0400,
115 "Enable PSR2 selective fetch "
116 "(0=disabled, 1=enabled) "
117 "Default: 1");
118
119__maybe_unused
120static void _param_print_bool(struct drm_printer *p, const char *driver_name,
121 const char *name, bool val)
122{
123 drm_printf(p, f: "%s.%s=%s\n", driver_name, name, str_yes_no(v: val));
124}
125
126__maybe_unused
127static void _param_print_int(struct drm_printer *p, const char *driver_name,
128 const char *name, int val)
129{
130 drm_printf(p, f: "%s.%s=%d\n", driver_name, name, val);
131}
132
133__maybe_unused
134static void _param_print_uint(struct drm_printer *p, const char *driver_name,
135 const char *name, unsigned int val)
136{
137 drm_printf(p, f: "%s.%s=%u\n", driver_name, name, val);
138}
139
140__maybe_unused
141static void _param_print_ulong(struct drm_printer *p, const char *driver_name,
142 const char *name, unsigned long val)
143{
144 drm_printf(p, f: "%s.%s=%lu\n", driver_name, name, val);
145}
146
147__maybe_unused
148static void _param_print_charp(struct drm_printer *p, const char *driver_name,
149 const char *name, const char *val)
150{
151 drm_printf(p, f: "%s.%s=%s\n", driver_name, name, val);
152}
153
154#define _param_print(p, driver_name, name, val) \
155 _Generic(val, \
156 bool : _param_print_bool, \
157 int : _param_print_int, \
158 unsigned int : _param_print_uint, \
159 unsigned long : _param_print_ulong, \
160 char * : _param_print_charp)(p, driver_name, name, val)
161
162/**
163 * intel_display_params_dump - dump intel display modparams
164 * @i915: i915 device
165 * @p: the &drm_printer
166 *
167 * Pretty printer for i915 modparams.
168 */
169void intel_display_params_dump(struct drm_i915_private *i915, struct drm_printer *p)
170{
171#define PRINT(T, x, ...) _param_print(p, i915->drm.driver->name, #x, i915->display.params.x);
172 INTEL_DISPLAY_PARAMS_FOR_EACH(PRINT);
173#undef PRINT
174}
175
176__maybe_unused static void _param_dup_charp(char **valp)
177{
178 *valp = kstrdup(s: *valp ? *valp : "", GFP_ATOMIC);
179}
180
181__maybe_unused static void _param_nop(void *valp)
182{
183}
184
185#define _param_dup(valp) \
186 _Generic(valp, \
187 char ** : _param_dup_charp, \
188 default : _param_nop) \
189 (valp)
190
191void intel_display_params_copy(struct intel_display_params *dest)
192{
193 *dest = intel_display_modparams;
194#define DUP(T, x, ...) _param_dup(&dest->x);
195 INTEL_DISPLAY_PARAMS_FOR_EACH(DUP);
196#undef DUP
197}
198
199__maybe_unused static void _param_free_charp(char **valp)
200{
201 kfree(objp: *valp);
202 *valp = NULL;
203}
204
205#define _param_free(valp) \
206 _Generic(valp, \
207 char ** : _param_free_charp, \
208 default : _param_nop) \
209 (valp)
210
211/* free the allocated members, *not* the passed in params itself */
212void intel_display_params_free(struct intel_display_params *params)
213{
214#define FREE(T, x, ...) _param_free(&params->x);
215 INTEL_DISPLAY_PARAMS_FOR_EACH(FREE);
216#undef FREE
217}
218

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