xref: /linux/drivers/gpu/drm/i915/display/intel_casf.c (revision 815e260a18a3af4dab59025ee99a7156c0e8b5e0)
1 // SPDX-License-Identifier: MIT
2 /* Copyright © 2025 Intel Corporation */
3 
4 #include <drm/drm_print.h>
5 
6 #include "i915_reg.h"
7 #include "intel_casf.h"
8 #include "intel_casf_regs.h"
9 #include "intel_de.h"
10 #include "intel_display_regs.h"
11 #include "intel_display_types.h"
12 #include "skl_scaler.h"
13 
14 #define MAX_PIXELS_FOR_3_TAP_FILTER (1920 * 1080)
15 #define MAX_PIXELS_FOR_5_TAP_FILTER (3840 * 2160)
16 
17 #define FILTER_COEFF_0_125 125
18 #define FILTER_COEFF_0_25 250
19 #define FILTER_COEFF_0_5 500
20 #define FILTER_COEFF_1_0 1000
21 #define FILTER_COEFF_0_0 0
22 #define SET_POSITIVE_SIGN(x) ((x) & (~SIGN))
23 
24 /**
25  * DOC: Content Adaptive Sharpness Filter (CASF)
26  *
27  * Starting from LNL the display engine supports an
28  * adaptive sharpening filter, enhancing the image
29  * quality. The display hardware utilizes the second
30  * pipe scaler for implementing CASF.
31  * If sharpness is being enabled then pipe scaling
32  * cannot be used.
33  * This filter operates on a region of pixels based
34  * on the tap size. Coefficients are used to generate
35  * an alpha value which blends the sharpened image to
36  * original image.
37  */
38 
39 /* Default LUT values to be loaded one time. */
40 static const u16 sharpness_lut[] = {
41 	4095, 2047, 1364, 1022, 816, 678, 579,
42 	504, 444, 397, 357, 323, 293, 268, 244, 224,
43 	204, 187, 170, 154, 139, 125, 111, 98, 85,
44 	73, 60, 48, 36, 24, 12, 0
45 };
46 
47 const u16 filtercoeff_1[] = {
48 	FILTER_COEFF_0_0, FILTER_COEFF_0_0, FILTER_COEFF_0_5,
49 	FILTER_COEFF_1_0, FILTER_COEFF_0_5, FILTER_COEFF_0_0,
50 	FILTER_COEFF_0_0,
51 };
52 
53 const u16 filtercoeff_2[] = {
54 	FILTER_COEFF_0_0, FILTER_COEFF_0_25, FILTER_COEFF_0_5,
55 	FILTER_COEFF_1_0, FILTER_COEFF_0_5, FILTER_COEFF_0_25,
56 	FILTER_COEFF_0_0,
57 };
58 
59 const u16 filtercoeff_3[] = {
60 	FILTER_COEFF_0_125, FILTER_COEFF_0_25, FILTER_COEFF_0_5,
61 	FILTER_COEFF_1_0, FILTER_COEFF_0_5, FILTER_COEFF_0_25,
62 	FILTER_COEFF_0_125,
63 };
64 
65 static void intel_casf_filter_lut_load(struct intel_crtc *crtc,
66 				       const struct intel_crtc_state *crtc_state)
67 {
68 	struct intel_display *display = to_intel_display(crtc_state);
69 	int i;
70 
71 	intel_de_write(display, SHRPLUT_INDEX(crtc->pipe),
72 		       INDEX_AUTO_INCR | INDEX_VALUE(0));
73 
74 	for (i = 0; i < ARRAY_SIZE(sharpness_lut); i++)
75 		intel_de_write(display, SHRPLUT_DATA(crtc->pipe),
76 			       sharpness_lut[i]);
77 }
78 
79 void intel_casf_update_strength(struct intel_crtc_state *crtc_state)
80 {
81 	struct intel_display *display = to_intel_display(crtc_state);
82 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
83 	int win_size;
84 
85 	intel_de_rmw(display, SHARPNESS_CTL(crtc->pipe), FILTER_STRENGTH_MASK,
86 		     FILTER_STRENGTH(crtc_state->hw.casf_params.strength));
87 
88 	win_size = intel_de_read(display, SKL_PS_WIN_SZ(crtc->pipe, 1));
89 
90 	intel_de_write_fw(display, SKL_PS_WIN_SZ(crtc->pipe, 1), win_size);
91 }
92 
93 static void intel_casf_compute_win_size(struct intel_crtc_state *crtc_state)
94 {
95 	const struct drm_display_mode *mode = &crtc_state->hw.adjusted_mode;
96 	u32 total_pixels = mode->hdisplay * mode->vdisplay;
97 
98 	if (total_pixels <= MAX_PIXELS_FOR_3_TAP_FILTER)
99 		crtc_state->hw.casf_params.win_size = SHARPNESS_FILTER_SIZE_3X3;
100 	else if (total_pixels <= MAX_PIXELS_FOR_5_TAP_FILTER)
101 		crtc_state->hw.casf_params.win_size = SHARPNESS_FILTER_SIZE_5X5;
102 	else
103 		crtc_state->hw.casf_params.win_size = SHARPNESS_FILTER_SIZE_7X7;
104 }
105 
106 int intel_casf_compute_config(struct intel_crtc_state *crtc_state)
107 {
108 	struct intel_display *display = to_intel_display(crtc_state);
109 
110 	if (!HAS_CASF(display))
111 		return 0;
112 
113 	if (crtc_state->uapi.sharpness_strength == 0) {
114 		crtc_state->hw.casf_params.casf_enable = false;
115 		crtc_state->hw.casf_params.strength = 0;
116 		return 0;
117 	}
118 
119 	crtc_state->hw.casf_params.casf_enable = true;
120 
121 	/*
122 	 * HW takes a value in form (1.0 + strength) in 4.4 fixed format.
123 	 * Strength is from 0.0-14.9375 ie from 0-239.
124 	 * User can give value from 0-255 but is clamped to 239.
125 	 * Ex. User gives 85 which is 5.3125 and adding 1.0 gives 6.3125.
126 	 * 6.3125 in 4.4 format is b01100101 which is equal to 101.
127 	 * Also 85 + 16 = 101.
128 	 */
129 	crtc_state->hw.casf_params.strength =
130 		min(crtc_state->uapi.sharpness_strength, 0xEF) + 0x10;
131 
132 	intel_casf_compute_win_size(crtc_state);
133 
134 	intel_casf_scaler_compute_config(crtc_state);
135 
136 	return 0;
137 }
138 
139 void intel_casf_sharpness_get_config(struct intel_crtc_state *crtc_state)
140 {
141 	struct intel_display *display = to_intel_display(crtc_state);
142 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
143 	u32 sharp;
144 
145 	sharp = intel_de_read(display, SHARPNESS_CTL(crtc->pipe));
146 	if (sharp & FILTER_EN) {
147 		if (drm_WARN_ON(display->drm,
148 				REG_FIELD_GET(FILTER_STRENGTH_MASK, sharp) < 16))
149 			crtc_state->hw.casf_params.strength = 0;
150 		else
151 			crtc_state->hw.casf_params.strength =
152 				REG_FIELD_GET(FILTER_STRENGTH_MASK, sharp);
153 		crtc_state->hw.casf_params.casf_enable = true;
154 		crtc_state->hw.casf_params.win_size =
155 			REG_FIELD_GET(FILTER_SIZE_MASK, sharp);
156 	}
157 }
158 
159 bool intel_casf_needs_scaler(const struct intel_crtc_state *crtc_state)
160 {
161 	if (crtc_state->hw.casf_params.casf_enable)
162 		return true;
163 
164 	return false;
165 }
166 
167 static int casf_coeff_tap(int i)
168 {
169 	return i % SCALER_FILTER_NUM_TAPS;
170 }
171 
172 static u32 casf_coeff(struct intel_crtc_state *crtc_state, int t)
173 {
174 	struct scaler_filter_coeff value;
175 	u32 coeff;
176 
177 	value = crtc_state->hw.casf_params.coeff[t];
178 	value.sign = 0;
179 
180 	coeff = value.sign << 15 | value.exp << 12 | value.mantissa << 3;
181 	return coeff;
182 }
183 
184 /*
185  * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set.
186  * To enable casf:  program scaler coefficients with the coeffients
187  * that are calculated and stored in hw.casf_params.coeff as per
188  * SCALER_COEFFICIENT_FORMAT
189  */
190 static void intel_casf_write_coeff(struct intel_crtc_state *crtc_state)
191 {
192 	struct intel_display *display = to_intel_display(crtc_state);
193 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
194 	int id = crtc_state->scaler_state.scaler_id;
195 	int i;
196 
197 	if (id != 1) {
198 		drm_WARN(display->drm, 0, "Second scaler not enabled\n");
199 		return;
200 	}
201 
202 	intel_de_write_fw(display, GLK_PS_COEF_INDEX_SET(crtc->pipe, id, 0),
203 			  PS_COEF_INDEX_AUTO_INC);
204 
205 	for (i = 0; i < 17 * SCALER_FILTER_NUM_TAPS; i += 2) {
206 		u32 tmp;
207 		int t;
208 
209 		t = casf_coeff_tap(i);
210 		tmp = casf_coeff(crtc_state, t);
211 
212 		t = casf_coeff_tap(i + 1);
213 		tmp |= casf_coeff(crtc_state, t) << 16;
214 
215 		intel_de_write_fw(display, GLK_PS_COEF_DATA_SET(crtc->pipe, id, 0),
216 				  tmp);
217 	}
218 }
219 
220 static void convert_sharpness_coef_binary(struct scaler_filter_coeff *coeff,
221 					  u16 coefficient)
222 {
223 	if (coefficient < 25) {
224 		coeff->mantissa = (coefficient * 2048) / 100;
225 		coeff->exp = 3;
226 	} else if (coefficient < 50) {
227 		coeff->mantissa = (coefficient * 1024) / 100;
228 		coeff->exp = 2;
229 	} else if (coefficient < 100) {
230 		coeff->mantissa = (coefficient * 512) / 100;
231 		coeff->exp = 1;
232 	} else {
233 		coeff->mantissa = (coefficient * 256) / 100;
234 		coeff->exp = 0;
235 	}
236 }
237 
238 void intel_casf_scaler_compute_config(struct intel_crtc_state *crtc_state)
239 {
240 	const u16 *filtercoeff;
241 	u16 filter_coeff[SCALER_FILTER_NUM_TAPS];
242 	u16 sumcoeff = 0;
243 	int i;
244 
245 	if (crtc_state->hw.casf_params.win_size == 0)
246 		filtercoeff = filtercoeff_1;
247 	else if (crtc_state->hw.casf_params.win_size == 1)
248 		filtercoeff = filtercoeff_2;
249 	else
250 		filtercoeff = filtercoeff_3;
251 
252 	for (i = 0; i < SCALER_FILTER_NUM_TAPS; i++)
253 		sumcoeff += *(filtercoeff + i);
254 
255 	for (i = 0; i < SCALER_FILTER_NUM_TAPS; i++) {
256 		filter_coeff[i] = (*(filtercoeff + i) * 100 / sumcoeff);
257 		convert_sharpness_coef_binary(&crtc_state->hw.casf_params.coeff[i],
258 					      filter_coeff[i]);
259 	}
260 }
261 
262 void intel_casf_enable(struct intel_crtc_state *crtc_state)
263 {
264 	struct intel_display *display = to_intel_display(crtc_state);
265 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
266 	u32 sharpness_ctl;
267 
268 	intel_casf_filter_lut_load(crtc, crtc_state);
269 
270 	intel_casf_write_coeff(crtc_state);
271 
272 	sharpness_ctl = FILTER_EN | FILTER_STRENGTH(crtc_state->hw.casf_params.strength);
273 
274 	sharpness_ctl |= crtc_state->hw.casf_params.win_size;
275 
276 	intel_de_write(display, SHARPNESS_CTL(crtc->pipe), sharpness_ctl);
277 
278 	skl_scaler_setup_casf(crtc_state);
279 }
280 
281 void intel_casf_disable(const struct intel_crtc_state *crtc_state)
282 {
283 	struct intel_display *display = to_intel_display(crtc_state);
284 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
285 
286 	intel_de_write(display, SKL_PS_CTRL(crtc->pipe, 1), 0);
287 	intel_de_write(display, SKL_PS_WIN_POS(crtc->pipe, 1), 0);
288 	intel_de_write(display, SHARPNESS_CTL(crtc->pipe), 0);
289 	intel_de_write(display, SKL_PS_WIN_SZ(crtc->pipe, 1), 0);
290 }
291