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25#include "intel_display_types.h"
26#include "intel_dp_aux_backlight.h"
27
28static void set_aux_backlight_enable(struct intel_dp *intel_dp, bool enable)
29{
30 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
31 u8 reg_val = 0;
32
33
34 if (!(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP))
35 return;
36
37 if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER,
38 ®_val) < 0) {
39 drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n",
40 DP_EDP_DISPLAY_CONTROL_REGISTER);
41 return;
42 }
43 if (enable)
44 reg_val |= DP_EDP_BACKLIGHT_ENABLE;
45 else
46 reg_val &= ~(DP_EDP_BACKLIGHT_ENABLE);
47
48 if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER,
49 reg_val) != 1) {
50 drm_dbg_kms(&i915->drm, "Failed to %s aux backlight\n",
51 enable ? "enable" : "disable");
52 }
53}
54
55static bool intel_dp_aux_backlight_dpcd_mode(struct intel_connector *connector)
56{
57 struct intel_dp *intel_dp = intel_attached_dp(connector);
58 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
59 u8 mode_reg;
60
61 if (drm_dp_dpcd_readb(&intel_dp->aux,
62 DP_EDP_BACKLIGHT_MODE_SET_REGISTER,
63 &mode_reg) != 1) {
64 drm_dbg_kms(&i915->drm,
65 "Failed to read the DPCD register 0x%x\n",
66 DP_EDP_BACKLIGHT_MODE_SET_REGISTER);
67 return false;
68 }
69
70 return (mode_reg & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) ==
71 DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
72}
73
74
75
76
77
78static u32 intel_dp_aux_get_backlight(struct intel_connector *connector)
79{
80 struct intel_dp *intel_dp = intel_attached_dp(connector);
81 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
82 u8 read_val[2] = { 0x0 };
83 u16 level = 0;
84
85
86
87
88
89 if (!intel_dp_aux_backlight_dpcd_mode(connector))
90 return connector->panel.backlight.max;
91
92 if (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB,
93 &read_val, sizeof(read_val)) < 0) {
94 drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n",
95 DP_EDP_BACKLIGHT_BRIGHTNESS_MSB);
96 return 0;
97 }
98 level = read_val[0];
99 if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT)
100 level = (read_val[0] << 8 | read_val[1]);
101
102 return level;
103}
104
105
106
107
108
109static void
110intel_dp_aux_set_backlight(const struct drm_connector_state *conn_state, u32 level)
111{
112 struct intel_connector *connector = to_intel_connector(conn_state->connector);
113 struct intel_dp *intel_dp = intel_attached_dp(connector);
114 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
115 u8 vals[2] = { 0x0 };
116
117 vals[0] = level;
118
119
120 if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) {
121 vals[0] = (level & 0xFF00) >> 8;
122 vals[1] = (level & 0xFF);
123 }
124 if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB,
125 vals, sizeof(vals)) < 0) {
126 drm_dbg_kms(&i915->drm,
127 "Failed to write aux backlight level\n");
128 return;
129 }
130}
131
132
133
134
135
136
137
138
139
140static bool intel_dp_aux_set_pwm_freq(struct intel_connector *connector)
141{
142 struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
143 struct intel_dp *intel_dp = intel_attached_dp(connector);
144 const u8 pn = connector->panel.backlight.pwmgen_bit_count;
145 int freq, fxp, f, fxp_actual, fxp_min, fxp_max;
146
147 freq = dev_priv->vbt.backlight.pwm_freq_hz;
148 if (!freq) {
149 drm_dbg_kms(&dev_priv->drm,
150 "Use panel default backlight frequency\n");
151 return false;
152 }
153
154 fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq);
155 f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255);
156 fxp_actual = f << pn;
157
158
159 fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
160 fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
161
162 if (fxp_min > fxp_actual || fxp_actual > fxp_max) {
163 drm_dbg_kms(&dev_priv->drm, "Actual frequency out of range\n");
164 return false;
165 }
166
167 if (drm_dp_dpcd_writeb(&intel_dp->aux,
168 DP_EDP_BACKLIGHT_FREQ_SET, (u8) f) < 0) {
169 drm_dbg_kms(&dev_priv->drm,
170 "Failed to write aux backlight freq\n");
171 return false;
172 }
173 return true;
174}
175
176static void intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_state,
177 const struct drm_connector_state *conn_state)
178{
179 struct intel_connector *connector = to_intel_connector(conn_state->connector);
180 struct intel_dp *intel_dp = intel_attached_dp(connector);
181 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
182 struct intel_panel *panel = &connector->panel;
183 u8 dpcd_buf, new_dpcd_buf, edp_backlight_mode;
184
185 if (drm_dp_dpcd_readb(&intel_dp->aux,
186 DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) != 1) {
187 drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n",
188 DP_EDP_BACKLIGHT_MODE_SET_REGISTER);
189 return;
190 }
191
192 new_dpcd_buf = dpcd_buf;
193 edp_backlight_mode = dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
194
195 switch (edp_backlight_mode) {
196 case DP_EDP_BACKLIGHT_CONTROL_MODE_PWM:
197 case DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET:
198 case DP_EDP_BACKLIGHT_CONTROL_MODE_PRODUCT:
199 new_dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
200 new_dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
201
202 if (drm_dp_dpcd_writeb(&intel_dp->aux,
203 DP_EDP_PWMGEN_BIT_COUNT,
204 panel->backlight.pwmgen_bit_count) < 0)
205 drm_dbg_kms(&i915->drm,
206 "Failed to write aux pwmgen bit count\n");
207
208 break;
209
210
211 case DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD:
212 default:
213 break;
214 }
215
216 if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
217 if (intel_dp_aux_set_pwm_freq(connector))
218 new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE;
219
220 if (new_dpcd_buf != dpcd_buf) {
221 if (drm_dp_dpcd_writeb(&intel_dp->aux,
222 DP_EDP_BACKLIGHT_MODE_SET_REGISTER, new_dpcd_buf) < 0) {
223 drm_dbg_kms(&i915->drm,
224 "Failed to write aux backlight mode\n");
225 }
226 }
227
228 intel_dp_aux_set_backlight(conn_state,
229 connector->panel.backlight.level);
230 set_aux_backlight_enable(intel_dp, true);
231}
232
233static void intel_dp_aux_disable_backlight(const struct drm_connector_state *old_conn_state)
234{
235 set_aux_backlight_enable(enc_to_intel_dp(to_intel_encoder(old_conn_state->best_encoder)),
236 false);
237}
238
239static u32 intel_dp_aux_calc_max_backlight(struct intel_connector *connector)
240{
241 struct drm_i915_private *i915 = to_i915(connector->base.dev);
242 struct intel_dp *intel_dp = intel_attached_dp(connector);
243 struct intel_panel *panel = &connector->panel;
244 u32 max_backlight = 0;
245 int freq, fxp, fxp_min, fxp_max, fxp_actual, f = 1;
246 u8 pn, pn_min, pn_max;
247
248 if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, &pn) == 1) {
249 pn &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
250 max_backlight = (1 << pn) - 1;
251 }
252
253
254
255
256
257 freq = i915->vbt.backlight.pwm_freq_hz;
258 drm_dbg_kms(&i915->drm, "VBT defined backlight frequency %u Hz\n",
259 freq);
260 if (!freq) {
261 drm_dbg_kms(&i915->drm,
262 "Use panel default backlight frequency\n");
263 return max_backlight;
264 }
265
266 fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq);
267
268
269
270
271
272
273
274
275 if (drm_dp_dpcd_readb(&intel_dp->aux,
276 DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min) != 1) {
277 drm_dbg_kms(&i915->drm,
278 "Failed to read pwmgen bit count cap min\n");
279 return max_backlight;
280 }
281 if (drm_dp_dpcd_readb(&intel_dp->aux,
282 DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max) != 1) {
283 drm_dbg_kms(&i915->drm,
284 "Failed to read pwmgen bit count cap max\n");
285 return max_backlight;
286 }
287 pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
288 pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
289
290 fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
291 fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
292 if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) {
293 drm_dbg_kms(&i915->drm,
294 "VBT defined backlight frequency out of range\n");
295 return max_backlight;
296 }
297
298 for (pn = pn_max; pn >= pn_min; pn--) {
299 f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255);
300 fxp_actual = f << pn;
301 if (fxp_min <= fxp_actual && fxp_actual <= fxp_max)
302 break;
303 }
304
305 drm_dbg_kms(&i915->drm, "Using eDP pwmgen bit count of %d\n", pn);
306 if (drm_dp_dpcd_writeb(&intel_dp->aux,
307 DP_EDP_PWMGEN_BIT_COUNT, pn) < 0) {
308 drm_dbg_kms(&i915->drm,
309 "Failed to write aux pwmgen bit count\n");
310 return max_backlight;
311 }
312 panel->backlight.pwmgen_bit_count = pn;
313
314 max_backlight = (1 << pn) - 1;
315
316 return max_backlight;
317}
318
319static int intel_dp_aux_setup_backlight(struct intel_connector *connector,
320 enum pipe pipe)
321{
322 struct intel_panel *panel = &connector->panel;
323
324 panel->backlight.max = intel_dp_aux_calc_max_backlight(connector);
325 if (!panel->backlight.max)
326 return -ENODEV;
327
328 panel->backlight.min = 0;
329 panel->backlight.level = intel_dp_aux_get_backlight(connector);
330 panel->backlight.enabled = intel_dp_aux_backlight_dpcd_mode(connector) &&
331 panel->backlight.level != 0;
332
333 return 0;
334}
335
336static bool
337intel_dp_aux_display_control_capable(struct intel_connector *connector)
338{
339 struct intel_dp *intel_dp = intel_attached_dp(connector);
340 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
341
342
343
344
345 if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP &&
346 (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) {
347 drm_dbg_kms(&i915->drm, "AUX Backlight Control Supported!\n");
348 return true;
349 }
350 return false;
351}
352
353int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
354{
355 struct intel_panel *panel = &intel_connector->panel;
356 struct intel_dp *intel_dp = enc_to_intel_dp(intel_connector->encoder);
357 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
358
359 if (i915->params.enable_dpcd_backlight == 0 ||
360 !intel_dp_aux_display_control_capable(intel_connector))
361 return -ENODEV;
362
363
364
365
366
367 if (i915->vbt.backlight.type !=
368 INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE &&
369 i915->params.enable_dpcd_backlight != 1 &&
370 !drm_dp_has_quirk(&intel_dp->desc, intel_dp->edid_quirks,
371 DP_QUIRK_FORCE_DPCD_BACKLIGHT)) {
372 drm_info(&i915->drm,
373 "Panel advertises DPCD backlight support, but "
374 "VBT disagrees. If your backlight controls "
375 "don't work try booting with "
376 "i915.enable_dpcd_backlight=1. If your machine "
377 "needs this, please file a _new_ bug report on "
378 "drm/i915, see " FDO_BUG_URL " for details.\n");
379 return -ENODEV;
380 }
381
382 panel->backlight.setup = intel_dp_aux_setup_backlight;
383 panel->backlight.enable = intel_dp_aux_enable_backlight;
384 panel->backlight.disable = intel_dp_aux_disable_backlight;
385 panel->backlight.set = intel_dp_aux_set_backlight;
386 panel->backlight.get = intel_dp_aux_get_backlight;
387
388 return 0;
389}
390