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
21 static 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
35 intel_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
39 intel_display_param_named_unsafe(vbt_firmware, charp, 0400,
40 "Load VBT from specified file under /lib/firmware");
41
42 intel_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
46 intel_display_param_named_unsafe(panel_use_ssc, int, 0400,
47 "Use Spread Spectrum Clock with panels [LVDS/eDP] "
48 "(default: auto from VBT)");
49
50 intel_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
54 intel_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
59 intel_display_param_named_unsafe(enable_dpt, bool, 0400,
60 "Enable display page table (DPT) (default: true)");
61
62 intel_display_param_named_unsafe(enable_dsb, bool, 0400,
63 "Enable display state buffer (DSB) (default: true)");
64
65 intel_display_param_named_unsafe(enable_flipq, bool, 0400,
66 "Enable DMC flip queue (default: false)");
67
68 intel_display_param_named_unsafe(enable_sagv, bool, 0400,
69 "Enable system agent voltage/frequency scaling (SAGV) (default: true)");
70
71 intel_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
75 intel_display_param_named_unsafe(enable_ips, bool, 0400, "Enable IPS (default: true)");
76
77 intel_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 */
85 intel_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
90 intel_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
94 intel_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
98 intel_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
102 intel_display_param_named(disable_display, bool, 0400,
103 "Disable display (default: false)");
104
105 intel_display_param_named(verbose_state_checks, bool, 0400,
106 "Enable verbose logs (ie. WARN_ON()) in case of unexpected hw state conditions.");
107
108 intel_display_param_named_unsafe(nuclear_pageflip, bool, 0400,
109 "Force enable atomic functionality on platforms that don't have full support yet.");
110
111 intel_display_param_named_unsafe(enable_dp_mst, bool, 0400,
112 "Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");
113
114 intel_display_param_named_unsafe(enable_fbc, int, 0400,
115 "Enable frame buffer compression for power savings "
116 "(default: -1 (use per-chip default))");
117
118 intel_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
123 intel_display_param_named(psr_safest_params, bool, 0400,
124 "Replace PSR VBT parameters by the safest and not optimal ones. This "
125 "is helpful to detect if PSR issues are related to bad values set in "
126 " VBT. (0=use VBT parameters, 1=use safest parameters)"
127 "Default: 0");
128
129 intel_display_param_named_unsafe(enable_psr2_sel_fetch, bool, 0400,
130 "Enable PSR2 and Panel Replay selective fetch "
131 "(0=disabled, 1=enabled) "
132 "Default: 1");
133
134 intel_display_param_named_unsafe(enable_dmc_wl, int, 0400,
135 "Enable DMC wakelock "
136 "(-1=use per-chip default, 0=disabled, 1=enabled, 2=match any register, 3=always locked) "
137 "Default: -1");
138
139 __maybe_unused
_param_print_bool(struct drm_printer * p,const char * driver_name,const char * name,bool val)140 static void _param_print_bool(struct drm_printer *p, const char *driver_name,
141 const char *name, bool val)
142 {
143 drm_printf(p, "%s.%s=%s\n", driver_name, name, str_yes_no(val));
144 }
145
146 __maybe_unused
_param_print_int(struct drm_printer * p,const char * driver_name,const char * name,int val)147 static void _param_print_int(struct drm_printer *p, const char *driver_name,
148 const char *name, int val)
149 {
150 drm_printf(p, "%s.%s=%d\n", driver_name, name, val);
151 }
152
153 __maybe_unused
_param_print_uint(struct drm_printer * p,const char * driver_name,const char * name,unsigned int val)154 static void _param_print_uint(struct drm_printer *p, const char *driver_name,
155 const char *name, unsigned int val)
156 {
157 drm_printf(p, "%s.%s=%u\n", driver_name, name, val);
158 }
159
160 __maybe_unused
_param_print_ulong(struct drm_printer * p,const char * driver_name,const char * name,unsigned long val)161 static void _param_print_ulong(struct drm_printer *p, const char *driver_name,
162 const char *name, unsigned long val)
163 {
164 drm_printf(p, "%s.%s=%lu\n", driver_name, name, val);
165 }
166
167 __maybe_unused
_param_print_charp(struct drm_printer * p,const char * driver_name,const char * name,const char * val)168 static void _param_print_charp(struct drm_printer *p, const char *driver_name,
169 const char *name, const char *val)
170 {
171 drm_printf(p, "%s.%s=%s\n", driver_name, name, val);
172 }
173
174 #define _param_print(p, driver_name, name, val) \
175 _Generic(val, \
176 bool : _param_print_bool, \
177 int : _param_print_int, \
178 unsigned int : _param_print_uint, \
179 unsigned long : _param_print_ulong, \
180 char * : _param_print_charp)(p, driver_name, name, val)
181
182 /**
183 * intel_display_params_dump - dump intel display modparams
184 * @params: display params
185 * @driver_name: driver name to use for printing
186 * @p: the &drm_printer
187 *
188 * Pretty printer for i915 modparams.
189 */
intel_display_params_dump(const struct intel_display_params * params,const char * driver_name,struct drm_printer * p)190 void intel_display_params_dump(const struct intel_display_params *params,
191 const char *driver_name, struct drm_printer *p)
192 {
193 #define PRINT(T, x, ...) _param_print(p, driver_name, #x, params->x);
194 INTEL_DISPLAY_PARAMS_FOR_EACH(PRINT);
195 #undef PRINT
196 }
197
_param_dup_charp(char ** valp)198 __maybe_unused static void _param_dup_charp(char **valp)
199 {
200 *valp = kstrdup(*valp ? *valp : "", GFP_ATOMIC);
201 }
202
_param_nop(void * valp)203 __maybe_unused static void _param_nop(void *valp)
204 {
205 }
206
207 #define _param_dup(valp) \
208 _Generic(valp, \
209 char ** : _param_dup_charp, \
210 default : _param_nop) \
211 (valp)
212
intel_display_params_copy(struct intel_display_params * dest)213 void intel_display_params_copy(struct intel_display_params *dest)
214 {
215 *dest = intel_display_modparams;
216 #define DUP(T, x, ...) _param_dup(&dest->x);
217 INTEL_DISPLAY_PARAMS_FOR_EACH(DUP);
218 #undef DUP
219 }
220
_param_free_charp(char ** valp)221 __maybe_unused static void _param_free_charp(char **valp)
222 {
223 kfree(*valp);
224 *valp = NULL;
225 }
226
227 #define _param_free(valp) \
228 _Generic(valp, \
229 char ** : _param_free_charp, \
230 default : _param_nop) \
231 (valp)
232
233 /* free the allocated members, *not* the passed in params itself */
intel_display_params_free(struct intel_display_params * params)234 void intel_display_params_free(struct intel_display_params *params)
235 {
236 #define FREE(T, x, ...) _param_free(¶ms->x);
237 INTEL_DISPLAY_PARAMS_FOR_EACH(FREE);
238 #undef FREE
239 }
240