xref: /linux/drivers/gpu/drm/i915/display/intel_display_params.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 
16 static 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 
30 intel_display_param_named_unsafe(dmc_firmware_path, charp, 0400,
31 	"DMC firmware path to use instead of the default one. "
32 	"Use /dev/null to disable DMC and runtime PM.");
33 
34 intel_display_param_named_unsafe(vbt_firmware, charp, 0400,
35 	"Load VBT from specified file under /lib/firmware");
36 
37 intel_display_param_named_unsafe(lvds_channel_mode, int, 0400,
38 	 "Specify LVDS channel mode "
39 	 "(0=probe BIOS [default], 1=single-channel, 2=dual-channel)");
40 
41 intel_display_param_named_unsafe(panel_use_ssc, int, 0400,
42 	"Use Spread Spectrum Clock with panels [LVDS/eDP] "
43 	"(default: auto from VBT)");
44 
45 intel_display_param_named_unsafe(vbt_sdvo_panel_type, int, 0400,
46 	"Override/Ignore selection of SDVO panel mode in the VBT "
47 	"(-2=ignore, -1=auto [default], index in VBT BIOS table)");
48 
49 intel_display_param_named_unsafe(enable_dc, int, 0400,
50 	"Enable power-saving display C-states. "
51 	"(-1=auto [default]; 0=disable; 1=up to DC5; 2=up to DC6; "
52 	"3=up to DC5 with DC3CO; 4=up to DC6 with DC3CO)");
53 
54 intel_display_param_named_unsafe(enable_dpt, bool, 0400,
55 	"Enable display page table (DPT) (default: true)");
56 
57 intel_display_param_named_unsafe(enable_dsb, bool, 0400,
58 	"Enable display state buffer (DSB) (default: true)");
59 
60 intel_display_param_named_unsafe(enable_sagv, bool, 0400,
61 	"Enable system agent voltage/frequency scaling (SAGV) (default: true)");
62 
63 intel_display_param_named_unsafe(disable_power_well, int, 0400,
64 	"Disable display power wells when possible "
65 	"(-1=auto [default], 0=power wells always on, 1=power wells disabled when possible)");
66 
67 intel_display_param_named_unsafe(enable_ips, bool, 0400, "Enable IPS (default: true)");
68 
69 intel_display_param_named_unsafe(invert_brightness, int, 0400,
70 	"Invert backlight brightness "
71 	"(-1 force normal, 0 machine defaults, 1 force inversion), please "
72 	"report PCI device ID, subsystem vendor and subsystem device ID "
73 	"to dri-devel@lists.freedesktop.org, if your machine needs it. "
74 	"It will then be included in an upcoming module version.");
75 
76 /* WA to get away with the default setting in VBT for early platforms.Will be removed */
77 intel_display_param_named_unsafe(edp_vswing, int, 0400,
78 	"Ignore/Override vswing pre-emph table selection from VBT "
79 	"(0=use value from vbt [default], 1=low power swing(200mV),"
80 	"2=default swing(400mV))");
81 
82 intel_display_param_named(enable_dpcd_backlight, int, 0400,
83 	"Enable support for DPCD backlight control"
84 	"(-1=use per-VBT LFP backlight type setting [default], 0=disabled, 1=enable, 2=force VESA interface, 3=force Intel interface)");
85 
86 intel_display_param_named_unsafe(load_detect_test, bool, 0400,
87 	"Force-enable the VGA load detect code for testing (default:false). "
88 	"For developers only.");
89 
90 intel_display_param_named_unsafe(force_reset_modeset_test, bool, 0400,
91 	"Force a modeset during gpu reset for testing (default:false). "
92 	"For developers only.");
93 
94 intel_display_param_named(disable_display, bool, 0400,
95 	"Disable display (default: false)");
96 
97 intel_display_param_named(verbose_state_checks, bool, 0400,
98 	"Enable verbose logs (ie. WARN_ON()) in case of unexpected hw state conditions.");
99 
100 intel_display_param_named_unsafe(nuclear_pageflip, bool, 0400,
101 	"Force enable atomic functionality on platforms that don't have full support yet.");
102 
103 intel_display_param_named_unsafe(enable_dp_mst, bool, 0400,
104 	"Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");
105 
106 intel_display_param_named_unsafe(enable_fbc, int, 0400,
107 	"Enable frame buffer compression for power savings "
108 	"(default: -1 (use per-chip default))");
109 
110 intel_display_param_named_unsafe(enable_psr, int, 0400,
111 	"Enable PSR "
112 	"(0=disabled, 1=enable up to PSR1, 2=enable up to PSR2) "
113 	"Default: -1 (use per-chip default)");
114 
115 intel_display_param_named(psr_safest_params, bool, 0400,
116 	"Replace PSR VBT parameters by the safest and not optimal ones. This "
117 	"is helpful to detect if PSR issues are related to bad values set in "
118 	" VBT. (0=use VBT parameters, 1=use safest parameters)"
119 	"Default: 0");
120 
121 intel_display_param_named_unsafe(enable_psr2_sel_fetch, bool, 0400,
122 	"Enable PSR2 and Panel Replay selective fetch "
123 	"(0=disabled, 1=enabled) "
124 	"Default: 1");
125 
126 intel_display_param_named_unsafe(enable_dmc_wl, bool, 0400,
127 	"Enable DMC wakelock "
128 	"(0=disabled, 1=enabled) "
129 	"Default: 0");
130 
131 __maybe_unused
132 static void _param_print_bool(struct drm_printer *p, const char *driver_name,
133 			      const char *name, bool val)
134 {
135 	drm_printf(p, "%s.%s=%s\n", driver_name, name, str_yes_no(val));
136 }
137 
138 __maybe_unused
139 static void _param_print_int(struct drm_printer *p, const char *driver_name,
140 			     const char *name, int val)
141 {
142 	drm_printf(p, "%s.%s=%d\n", driver_name, name, val);
143 }
144 
145 __maybe_unused
146 static void _param_print_uint(struct drm_printer *p, const char *driver_name,
147 			      const char *name, unsigned int val)
148 {
149 	drm_printf(p, "%s.%s=%u\n", driver_name, name, val);
150 }
151 
152 __maybe_unused
153 static void _param_print_ulong(struct drm_printer *p, const char *driver_name,
154 			       const char *name, unsigned long val)
155 {
156 	drm_printf(p, "%s.%s=%lu\n", driver_name, name, val);
157 }
158 
159 __maybe_unused
160 static void _param_print_charp(struct drm_printer *p, const char *driver_name,
161 			       const char *name, const char *val)
162 {
163 	drm_printf(p, "%s.%s=%s\n", driver_name, name, val);
164 }
165 
166 #define _param_print(p, driver_name, name, val)			\
167 	_Generic(val,						\
168 		 bool : _param_print_bool,			\
169 		 int : _param_print_int,			\
170 		 unsigned int : _param_print_uint,		\
171 		 unsigned long : _param_print_ulong,		\
172 		 char * : _param_print_charp)(p, driver_name, name, val)
173 
174 /**
175  * intel_display_params_dump - dump intel display modparams
176  * @display: display device
177  * @p: the &drm_printer
178  *
179  * Pretty printer for i915 modparams.
180  */
181 void intel_display_params_dump(struct intel_display *display, struct drm_printer *p)
182 {
183 #define PRINT(T, x, ...) _param_print(p, display->drm->driver->name, #x, display->params.x);
184 	INTEL_DISPLAY_PARAMS_FOR_EACH(PRINT);
185 #undef PRINT
186 }
187 
188 __maybe_unused static void _param_dup_charp(char **valp)
189 {
190 	*valp = kstrdup(*valp ? *valp : "", GFP_ATOMIC);
191 }
192 
193 __maybe_unused static void _param_nop(void *valp)
194 {
195 }
196 
197 #define _param_dup(valp)				\
198 	_Generic(valp,					\
199 		 char ** : _param_dup_charp,		\
200 		 default : _param_nop)			\
201 		(valp)
202 
203 void intel_display_params_copy(struct intel_display_params *dest)
204 {
205 	*dest = intel_display_modparams;
206 #define DUP(T, x, ...) _param_dup(&dest->x);
207 	INTEL_DISPLAY_PARAMS_FOR_EACH(DUP);
208 #undef DUP
209 }
210 
211 __maybe_unused static void _param_free_charp(char **valp)
212 {
213 	kfree(*valp);
214 	*valp = NULL;
215 }
216 
217 #define _param_free(valp)				\
218 	_Generic(valp,					\
219 		 char ** : _param_free_charp,		\
220 		 default : _param_nop)			\
221 		(valp)
222 
223 /* free the allocated members, *not* the passed in params itself */
224 void intel_display_params_free(struct intel_display_params *params)
225 {
226 #define FREE(T, x, ...) _param_free(&params->x);
227 	INTEL_DISPLAY_PARAMS_FOR_EACH(FREE);
228 #undef FREE
229 }
230