xref: /linux/drivers/gpu/drm/i915/display/intel_casf.c (revision 53597deca0e38c30e6cd4ba2114fa42d2bcd85bb)
1 // SPDX-License-Identifier: MIT
2 /* Copyright © 2025 Intel Corporation */
3 
4 #include <drm/drm_print.h>
5 
6 #include "intel_casf.h"
7 #include "intel_casf_regs.h"
8 #include "intel_de.h"
9 #include "intel_display_regs.h"
10 #include "intel_display_types.h"
11 #include "skl_scaler.h"
12 
13 #define MAX_PIXELS_FOR_3_TAP_FILTER (1920 * 1080)
14 #define MAX_PIXELS_FOR_5_TAP_FILTER (3840 * 2160)
15 
16 #define FILTER_COEFF_0_125 125
17 #define FILTER_COEFF_0_25 250
18 #define FILTER_COEFF_0_5 500
19 #define FILTER_COEFF_1_0 1000
20 #define FILTER_COEFF_0_0 0
21 #define SET_POSITIVE_SIGN(x) ((x) & (~SIGN))
22 
23 /**
24  * DOC: Content Adaptive Sharpness Filter (CASF)
25  *
26  * Starting from LNL the display engine supports an
27  * adaptive sharpening filter, enhancing the image
28  * quality. The display hardware utilizes the second
29  * pipe scaler for implementing CASF.
30  * If sharpness is being enabled then pipe scaling
31  * cannot be used.
32  * This filter operates on a region of pixels based
33  * on the tap size. Coefficients are used to generate
34  * an alpha value which blends the sharpened image to
35  * original image.
36  */
37 
38 /* Default LUT values to be loaded one time. */
39 static const u16 sharpness_lut[] = {
40 	4095, 2047, 1364, 1022, 816, 678, 579,
41 	504, 444, 397, 357, 323, 293, 268, 244, 224,
42 	204, 187, 170, 154, 139, 125, 111, 98, 85,
43 	73, 60, 48, 36, 24, 12, 0
44 };
45 
46 const u16 filtercoeff_1[] = {
47 	FILTER_COEFF_0_0, FILTER_COEFF_0_0, FILTER_COEFF_0_5,
48 	FILTER_COEFF_1_0, FILTER_COEFF_0_5, FILTER_COEFF_0_0,
49 	FILTER_COEFF_0_0,
50 };
51 
52 const u16 filtercoeff_2[] = {
53 	FILTER_COEFF_0_0, FILTER_COEFF_0_25, FILTER_COEFF_0_5,
54 	FILTER_COEFF_1_0, FILTER_COEFF_0_5, FILTER_COEFF_0_25,
55 	FILTER_COEFF_0_0,
56 };
57 
58 const u16 filtercoeff_3[] = {
59 	FILTER_COEFF_0_125, FILTER_COEFF_0_25, FILTER_COEFF_0_5,
60 	FILTER_COEFF_1_0, FILTER_COEFF_0_5, FILTER_COEFF_0_25,
61 	FILTER_COEFF_0_125,
62 };
63 
64 static void intel_casf_filter_lut_load(struct intel_crtc *crtc,
65 				       const struct intel_crtc_state *crtc_state)
66 {
67 	struct intel_display *display = to_intel_display(crtc_state);
68 	int i;
69 
70 	intel_de_write(display, SHRPLUT_INDEX(crtc->pipe),
71 		       INDEX_AUTO_INCR | INDEX_VALUE(0));
72 
73 	for (i = 0; i < ARRAY_SIZE(sharpness_lut); i++)
74 		intel_de_write(display, SHRPLUT_DATA(crtc->pipe),
75 			       sharpness_lut[i]);
76 }
77 
78 void intel_casf_update_strength(struct intel_crtc_state *crtc_state)
79 {
80 	struct intel_display *display = to_intel_display(crtc_state);
81 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
82 	int win_size;
83 
84 	intel_de_rmw(display, SHARPNESS_CTL(crtc->pipe), FILTER_STRENGTH_MASK,
85 		     FILTER_STRENGTH(crtc_state->hw.casf_params.strength));
86 
87 	win_size = intel_de_read(display, SKL_PS_WIN_SZ(crtc->pipe, 1));
88 
89 	intel_de_write_fw(display, SKL_PS_WIN_SZ(crtc->pipe, 1), win_size);
90 }
91 
92 static void intel_casf_compute_win_size(struct intel_crtc_state *crtc_state)
93 {
94 	const struct drm_display_mode *mode = &crtc_state->hw.adjusted_mode;
95 	u32 total_pixels = mode->hdisplay * mode->vdisplay;
96 
97 	if (total_pixels <= MAX_PIXELS_FOR_3_TAP_FILTER)
98 		crtc_state->hw.casf_params.win_size = SHARPNESS_FILTER_SIZE_3X3;
99 	else if (total_pixels <= MAX_PIXELS_FOR_5_TAP_FILTER)
100 		crtc_state->hw.casf_params.win_size = SHARPNESS_FILTER_SIZE_5X5;
101 	else
102 		crtc_state->hw.casf_params.win_size = SHARPNESS_FILTER_SIZE_7X7;
103 }
104 
105 int intel_casf_compute_config(struct intel_crtc_state *crtc_state)
106 {
107 	struct intel_display *display = to_intel_display(crtc_state);
108 
109 	if (!HAS_CASF(display))
110 		return 0;
111 
112 	if (crtc_state->uapi.sharpness_strength == 0) {
113 		crtc_state->hw.casf_params.casf_enable = false;
114 		crtc_state->hw.casf_params.strength = 0;
115 		return 0;
116 	}
117 
118 	/* CASF with joiner not supported in hardware */
119 	if (crtc_state->joiner_pipes) {
120 		drm_dbg_kms(display->drm, "CASF not supported with joiner\n");
121 		return -EINVAL;
122 	}
123 
124 	crtc_state->hw.casf_params.casf_enable = true;
125 
126 	/*
127 	 * HW takes a value in form (1.0 + strength) in 4.4 fixed format.
128 	 * Strength is from 0.0-14.9375 ie from 0-239.
129 	 * User can give value from 0-255 but is clamped to 239.
130 	 * Ex. User gives 85 which is 5.3125 and adding 1.0 gives 6.3125.
131 	 * 6.3125 in 4.4 format is b01100101 which is equal to 101.
132 	 * Also 85 + 16 = 101.
133 	 */
134 	crtc_state->hw.casf_params.strength =
135 		min(crtc_state->uapi.sharpness_strength, 0xEF) + 0x10;
136 
137 	intel_casf_compute_win_size(crtc_state);
138 
139 	intel_casf_scaler_compute_config(crtc_state);
140 
141 	return 0;
142 }
143 
144 void intel_casf_sharpness_get_config(struct intel_crtc_state *crtc_state)
145 {
146 	struct intel_display *display = to_intel_display(crtc_state);
147 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
148 	u32 sharp;
149 
150 	sharp = intel_de_read(display, SHARPNESS_CTL(crtc->pipe));
151 	if (sharp & FILTER_EN) {
152 		if (drm_WARN_ON(display->drm,
153 				REG_FIELD_GET(FILTER_STRENGTH_MASK, sharp) < 16))
154 			crtc_state->hw.casf_params.strength = 0;
155 		else
156 			crtc_state->hw.casf_params.strength =
157 				REG_FIELD_GET(FILTER_STRENGTH_MASK, sharp);
158 		crtc_state->hw.casf_params.casf_enable = true;
159 		crtc_state->hw.casf_params.win_size =
160 			REG_FIELD_GET(FILTER_SIZE_MASK, sharp);
161 	}
162 }
163 
164 bool intel_casf_needs_scaler(const struct intel_crtc_state *crtc_state)
165 {
166 	if (crtc_state->hw.casf_params.casf_enable)
167 		return true;
168 
169 	return false;
170 }
171 
172 static int casf_coeff_tap(int i)
173 {
174 	return i % SCALER_FILTER_NUM_TAPS;
175 }
176 
177 static u32 casf_coeff(struct intel_crtc_state *crtc_state, int t)
178 {
179 	struct scaler_filter_coeff value;
180 	u32 coeff;
181 
182 	value = crtc_state->hw.casf_params.coeff[t];
183 	value.sign = 0;
184 
185 	coeff = value.sign << 15 | value.exp << 12 | value.mantissa << 3;
186 	return coeff;
187 }
188 
189 /*
190  * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set.
191  * To enable casf:  program scaler coefficients with the coeffients
192  * that are calculated and stored in hw.casf_params.coeff as per
193  * SCALER_COEFFICIENT_FORMAT
194  */
195 static void intel_casf_write_coeff(struct intel_crtc_state *crtc_state)
196 {
197 	struct intel_display *display = to_intel_display(crtc_state);
198 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
199 	int id = crtc_state->scaler_state.scaler_id;
200 	int i;
201 
202 	if (id != 1) {
203 		drm_WARN(display->drm, 0, "Second scaler not enabled\n");
204 		return;
205 	}
206 
207 	intel_de_write_fw(display, GLK_PS_COEF_INDEX_SET(crtc->pipe, id, 0),
208 			  PS_COEF_INDEX_AUTO_INC);
209 
210 	for (i = 0; i < 17 * SCALER_FILTER_NUM_TAPS; i += 2) {
211 		u32 tmp;
212 		int t;
213 
214 		t = casf_coeff_tap(i);
215 		tmp = casf_coeff(crtc_state, t);
216 
217 		t = casf_coeff_tap(i + 1);
218 		tmp |= casf_coeff(crtc_state, t) << 16;
219 
220 		intel_de_write_fw(display, GLK_PS_COEF_DATA_SET(crtc->pipe, id, 0),
221 				  tmp);
222 	}
223 }
224 
225 static void convert_sharpness_coef_binary(struct scaler_filter_coeff *coeff,
226 					  u16 coefficient)
227 {
228 	if (coefficient < 25) {
229 		coeff->mantissa = (coefficient * 2048) / 100;
230 		coeff->exp = 3;
231 	} else if (coefficient < 50) {
232 		coeff->mantissa = (coefficient * 1024) / 100;
233 		coeff->exp = 2;
234 	} else if (coefficient < 100) {
235 		coeff->mantissa = (coefficient * 512) / 100;
236 		coeff->exp = 1;
237 	} else {
238 		coeff->mantissa = (coefficient * 256) / 100;
239 		coeff->exp = 0;
240 	}
241 }
242 
243 void intel_casf_scaler_compute_config(struct intel_crtc_state *crtc_state)
244 {
245 	const u16 *filtercoeff;
246 	u16 filter_coeff[SCALER_FILTER_NUM_TAPS];
247 	u16 sumcoeff = 0;
248 	int i;
249 
250 	if (crtc_state->hw.casf_params.win_size == 0)
251 		filtercoeff = filtercoeff_1;
252 	else if (crtc_state->hw.casf_params.win_size == 1)
253 		filtercoeff = filtercoeff_2;
254 	else
255 		filtercoeff = filtercoeff_3;
256 
257 	for (i = 0; i < SCALER_FILTER_NUM_TAPS; i++)
258 		sumcoeff += *(filtercoeff + i);
259 
260 	for (i = 0; i < SCALER_FILTER_NUM_TAPS; i++) {
261 		filter_coeff[i] = (*(filtercoeff + i) * 100 / sumcoeff);
262 		convert_sharpness_coef_binary(&crtc_state->hw.casf_params.coeff[i],
263 					      filter_coeff[i]);
264 	}
265 }
266 
267 void intel_casf_enable(struct intel_crtc_state *crtc_state)
268 {
269 	struct intel_display *display = to_intel_display(crtc_state);
270 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
271 	u32 sharpness_ctl;
272 
273 	intel_casf_filter_lut_load(crtc, crtc_state);
274 
275 	intel_casf_write_coeff(crtc_state);
276 
277 	sharpness_ctl = FILTER_EN | FILTER_STRENGTH(crtc_state->hw.casf_params.strength);
278 
279 	sharpness_ctl |= crtc_state->hw.casf_params.win_size;
280 
281 	intel_de_write(display, SHARPNESS_CTL(crtc->pipe), sharpness_ctl);
282 
283 	skl_scaler_setup_casf(crtc_state);
284 }
285 
286 void intel_casf_disable(const struct intel_crtc_state *crtc_state)
287 {
288 	struct intel_display *display = to_intel_display(crtc_state);
289 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
290 
291 	intel_de_write(display, SKL_PS_CTRL(crtc->pipe, 1), 0);
292 	intel_de_write(display, SKL_PS_WIN_POS(crtc->pipe, 1), 0);
293 	intel_de_write(display, SHARPNESS_CTL(crtc->pipe), 0);
294 	intel_de_write(display, SKL_PS_WIN_SZ(crtc->pipe, 1), 0);
295 }
296