1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * rcar_du_group.c  --  R-Car Display Unit Channels Pair
4  *
5  * Copyright (C) 2013-2015 Renesas Electronics Corporation
6  *
7  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
8  */
9 
10 /*
11  * The R8A7779 DU is split in per-CRTC resources (scan-out engine, blending
12  * unit, timings generator, ...) and device-global resources (start/stop
13  * control, planes, ...) shared between the two CRTCs.
14  *
15  * The R8A7790 introduced a third CRTC with its own set of global resources.
16  * This would be modeled as two separate DU device instances if it wasn't for
17  * a handful or resources that are shared between the three CRTCs (mostly
18  * related to input and output routing). For this reason the R8A7790 DU must be
19  * modeled as a single device with three CRTCs, two sets of "semi-global"
20  * resources, and a few device-global resources.
21  *
22  * The rcar_du_group object is a driver specific object, without any real
23  * counterpart in the DU documentation, that models those semi-global resources.
24  */
25 
26 #include <linux/clk.h>
27 #include <linux/io.h>
28 
29 #include "rcar_du_drv.h"
30 #include "rcar_du_group.h"
31 #include "rcar_du_regs.h"
32 
rcar_du_group_read(struct rcar_du_group * rgrp,u32 reg)33 u32 rcar_du_group_read(struct rcar_du_group *rgrp, u32 reg)
34 {
35 	return rcar_du_read(rgrp->dev, rgrp->mmio_offset + reg);
36 }
37 
rcar_du_group_write(struct rcar_du_group * rgrp,u32 reg,u32 data)38 void rcar_du_group_write(struct rcar_du_group *rgrp, u32 reg, u32 data)
39 {
40 	rcar_du_write(rgrp->dev, rgrp->mmio_offset + reg, data);
41 }
42 
rcar_du_group_setup_pins(struct rcar_du_group * rgrp)43 static void rcar_du_group_setup_pins(struct rcar_du_group *rgrp)
44 {
45 	u32 defr6 = DEFR6_CODE;
46 
47 	if (rgrp->channels_mask & BIT(0))
48 		defr6 |= DEFR6_ODPM02_DISP;
49 
50 	if (rgrp->channels_mask & BIT(1))
51 		defr6 |= DEFR6_ODPM12_DISP;
52 
53 	rcar_du_group_write(rgrp, DEFR6, defr6);
54 }
55 
rcar_du_group_setup_defr8(struct rcar_du_group * rgrp)56 static void rcar_du_group_setup_defr8(struct rcar_du_group *rgrp)
57 {
58 	struct rcar_du_device *rcdu = rgrp->dev;
59 	u32 defr8 = DEFR8_CODE;
60 
61 	if (rcdu->info->gen < 3) {
62 		defr8 |= DEFR8_DEFE8;
63 
64 		/*
65 		 * On Gen2 the DEFR8 register for the first group also controls
66 		 * RGB output routing to DPAD0 and VSPD1 routing to DU0/1/2 for
67 		 * DU instances that support it.
68 		 */
69 		if (rgrp->index == 0) {
70 			defr8 |= DEFR8_DRGBS_DU(rcdu->dpad0_source);
71 			if (rgrp->dev->vspd1_sink == 2)
72 				defr8 |= DEFR8_VSCS;
73 		}
74 	} else {
75 		/*
76 		 * On Gen3 VSPD routing can't be configured, and DPAD routing
77 		 * is set in the group corresponding to the DPAD output (no Gen3
78 		 * SoC has multiple DPAD sources belonging to separate groups).
79 		 */
80 		if (rgrp->index == rcdu->dpad0_source / 2)
81 			defr8 |= DEFR8_DRGBS_DU(rcdu->dpad0_source);
82 	}
83 
84 	rcar_du_group_write(rgrp, DEFR8, defr8);
85 }
86 
rcar_du_group_setup_didsr(struct rcar_du_group * rgrp)87 static void rcar_du_group_setup_didsr(struct rcar_du_group *rgrp)
88 {
89 	struct rcar_du_device *rcdu = rgrp->dev;
90 	struct rcar_du_crtc *rcrtc;
91 	unsigned int num_crtcs = 0;
92 	unsigned int i;
93 	u32 didsr;
94 
95 	/*
96 	 * Configure input dot clock routing with a hardcoded configuration. If
97 	 * the DU channel can use the LVDS encoder output clock as the dot
98 	 * clock, do so. Otherwise route DU_DOTCLKINn signal to DUn.
99 	 *
100 	 * Each channel can then select between the dot clock configured here
101 	 * and the clock provided by the CPG through the ESCR register.
102 	 */
103 	if (rcdu->info->gen < 3 && rgrp->index == 0) {
104 		/*
105 		 * On Gen2 a single register in the first group controls dot
106 		 * clock selection for all channels.
107 		 */
108 		rcrtc = rcdu->crtcs;
109 		num_crtcs = rcdu->num_crtcs;
110 	} else if (rcdu->info->gen == 3 && rgrp->num_crtcs > 1) {
111 		/*
112 		 * On Gen3 dot clocks are setup through per-group registers,
113 		 * only available when the group has two channels.
114 		 */
115 		rcrtc = &rcdu->crtcs[rgrp->index * 2];
116 		num_crtcs = rgrp->num_crtcs;
117 	}
118 
119 	if (!num_crtcs)
120 		return;
121 
122 	didsr = DIDSR_CODE;
123 	for (i = 0; i < num_crtcs; ++i, ++rcrtc) {
124 		if (rcdu->info->lvds_clk_mask & BIT(rcrtc->index))
125 			didsr |= DIDSR_LDCS_LVDS0(i)
126 			      |  DIDSR_PDCS_CLK(i, 0);
127 		else if (rcdu->info->dsi_clk_mask & BIT(rcrtc->index))
128 			didsr |= DIDSR_LDCS_DSI(i);
129 		else
130 			didsr |= DIDSR_LDCS_DCLKIN(i)
131 			      |  DIDSR_PDCS_CLK(i, 0);
132 	}
133 
134 	rcar_du_group_write(rgrp, DIDSR, didsr);
135 }
136 
rcar_du_group_setup(struct rcar_du_group * rgrp)137 static void rcar_du_group_setup(struct rcar_du_group *rgrp)
138 {
139 	struct rcar_du_device *rcdu = rgrp->dev;
140 	u32 defr7 = DEFR7_CODE;
141 
142 	/* Enable extended features */
143 	rcar_du_group_write(rgrp, DEFR, DEFR_CODE | DEFR_DEFE);
144 	if (rcdu->info->gen < 3) {
145 		rcar_du_group_write(rgrp, DEFR2, DEFR2_CODE | DEFR2_DEFE2G);
146 		rcar_du_group_write(rgrp, DEFR3, DEFR3_CODE | DEFR3_DEFE3);
147 		rcar_du_group_write(rgrp, DEFR4, DEFR4_CODE);
148 	}
149 	rcar_du_group_write(rgrp, DEFR5, DEFR5_CODE | DEFR5_DEFE5);
150 
151 	rcar_du_group_setup_pins(rgrp);
152 
153 	/*
154 	 * TODO: Handle routing of the DU output to CMM dynamically, as we
155 	 * should bypass CMM completely when no color management feature is
156 	 * used.
157 	 */
158 	defr7 |= (rgrp->cmms_mask & BIT(1) ? DEFR7_CMME1 : 0) |
159 		 (rgrp->cmms_mask & BIT(0) ? DEFR7_CMME0 : 0);
160 	rcar_du_group_write(rgrp, DEFR7, defr7);
161 
162 	if (rcdu->info->gen >= 2) {
163 		rcar_du_group_setup_defr8(rgrp);
164 		rcar_du_group_setup_didsr(rgrp);
165 	}
166 
167 	if (rcdu->info->gen >= 3)
168 		rcar_du_group_write(rgrp, DEFR10, DEFR10_CODE | DEFR10_DEFE10);
169 
170 	/*
171 	 * Use DS1PR and DS2PR to configure planes priorities and connects the
172 	 * superposition 0 to DU0 pins. DU1 pins will be configured dynamically.
173 	 */
174 	rcar_du_group_write(rgrp, DORCR, DORCR_PG1D_DS1 | DORCR_DPRS);
175 
176 	/* Apply planes to CRTCs association. */
177 	mutex_lock(&rgrp->lock);
178 	rcar_du_group_write(rgrp, DPTSR, (rgrp->dptsr_planes << 16) |
179 			    rgrp->dptsr_planes);
180 	mutex_unlock(&rgrp->lock);
181 }
182 
183 /*
184  * rcar_du_group_get - Acquire a reference to the DU channels group
185  *
186  * Acquiring the first reference setups core registers. A reference must be held
187  * before accessing any hardware registers.
188  *
189  * This function must be called with the DRM mode_config lock held.
190  *
191  * Return 0 in case of success or a negative error code otherwise.
192  */
rcar_du_group_get(struct rcar_du_group * rgrp)193 int rcar_du_group_get(struct rcar_du_group *rgrp)
194 {
195 	if (rgrp->use_count)
196 		goto done;
197 
198 	rcar_du_group_setup(rgrp);
199 
200 done:
201 	rgrp->use_count++;
202 	return 0;
203 }
204 
205 /*
206  * rcar_du_group_put - Release a reference to the DU
207  *
208  * This function must be called with the DRM mode_config lock held.
209  */
rcar_du_group_put(struct rcar_du_group * rgrp)210 void rcar_du_group_put(struct rcar_du_group *rgrp)
211 {
212 	--rgrp->use_count;
213 }
214 
__rcar_du_group_start_stop(struct rcar_du_group * rgrp,bool start)215 static void __rcar_du_group_start_stop(struct rcar_du_group *rgrp, bool start)
216 {
217 	struct rcar_du_device *rcdu = rgrp->dev;
218 
219 	/*
220 	 * Group start/stop is controlled by the DRES and DEN bits of DSYSR0
221 	 * for the first group and DSYSR2 for the second group. On most DU
222 	 * instances, this maps to the first CRTC of the group, and we can just
223 	 * use rcar_du_crtc_dsysr_clr_set() to access the correct DSYSR. On
224 	 * M3-N, however, DU2 doesn't exist, but DSYSR2 does. We thus need to
225 	 * access the register directly using group read/write.
226 	 */
227 	if (rcdu->info->channels_mask & BIT(rgrp->index * 2)) {
228 		struct rcar_du_crtc *rcrtc = &rgrp->dev->crtcs[rgrp->index * 2];
229 
230 		rcar_du_crtc_dsysr_clr_set(rcrtc, DSYSR_DRES | DSYSR_DEN,
231 					   start ? DSYSR_DEN : DSYSR_DRES);
232 	} else {
233 		rcar_du_group_write(rgrp, DSYSR,
234 				    start ? DSYSR_DEN : DSYSR_DRES);
235 	}
236 }
237 
rcar_du_group_start_stop(struct rcar_du_group * rgrp,bool start)238 void rcar_du_group_start_stop(struct rcar_du_group *rgrp, bool start)
239 {
240 	/*
241 	 * Many of the configuration bits are only updated when the display
242 	 * reset (DRES) bit in DSYSR is set to 1, disabling *both* CRTCs. Some
243 	 * of those bits could be pre-configured, but others (especially the
244 	 * bits related to plane assignment to display timing controllers) need
245 	 * to be modified at runtime.
246 	 *
247 	 * Restart the display controller if a start is requested. Sorry for the
248 	 * flicker. It should be possible to move most of the "DRES-update" bits
249 	 * setup to driver initialization time and minimize the number of cases
250 	 * when the display controller will have to be restarted.
251 	 */
252 	if (start) {
253 		if (rgrp->used_crtcs++ != 0)
254 			__rcar_du_group_start_stop(rgrp, false);
255 		__rcar_du_group_start_stop(rgrp, true);
256 	} else {
257 		if (--rgrp->used_crtcs == 0)
258 			__rcar_du_group_start_stop(rgrp, false);
259 	}
260 }
261 
rcar_du_group_restart(struct rcar_du_group * rgrp)262 void rcar_du_group_restart(struct rcar_du_group *rgrp)
263 {
264 	rgrp->need_restart = false;
265 
266 	__rcar_du_group_start_stop(rgrp, false);
267 	__rcar_du_group_start_stop(rgrp, true);
268 }
269 
rcar_du_set_dpad0_vsp1_routing(struct rcar_du_device * rcdu)270 int rcar_du_set_dpad0_vsp1_routing(struct rcar_du_device *rcdu)
271 {
272 	struct rcar_du_group *rgrp;
273 	struct rcar_du_crtc *crtc;
274 	unsigned int index;
275 	int ret;
276 
277 	if (rcdu->info->gen < 2)
278 		return 0;
279 
280 	/*
281 	 * RGB output routing to DPAD0 and VSP1D routing to DU0/1/2 are
282 	 * configured in the DEFR8 register of the first group on Gen2 and the
283 	 * last group on Gen3. As this function can be called with the DU
284 	 * channels of the corresponding CRTCs disabled, we need to enable the
285 	 * group clock before accessing the register.
286 	 */
287 	index = rcdu->info->gen < 3 ? 0 : DIV_ROUND_UP(rcdu->num_crtcs, 2) - 1;
288 	rgrp = &rcdu->groups[index];
289 	crtc = &rcdu->crtcs[index * 2];
290 
291 	ret = clk_prepare_enable(crtc->clock);
292 	if (ret < 0)
293 		return ret;
294 
295 	rcar_du_group_setup_defr8(rgrp);
296 
297 	clk_disable_unprepare(crtc->clock);
298 
299 	return 0;
300 }
301 
rcar_du_group_set_dpad_levels(struct rcar_du_group * rgrp)302 static void rcar_du_group_set_dpad_levels(struct rcar_du_group *rgrp)
303 {
304 	static const u32 doflr_values[2] = {
305 		DOFLR_HSYCFL0 | DOFLR_VSYCFL0 | DOFLR_ODDFL0 |
306 		DOFLR_DISPFL0 | DOFLR_CDEFL0  | DOFLR_RGBFL0,
307 		DOFLR_HSYCFL1 | DOFLR_VSYCFL1 | DOFLR_ODDFL1 |
308 		DOFLR_DISPFL1 | DOFLR_CDEFL1  | DOFLR_RGBFL1,
309 	};
310 	static const u32 dpad_mask = BIT(RCAR_DU_OUTPUT_DPAD1)
311 				   | BIT(RCAR_DU_OUTPUT_DPAD0);
312 	struct rcar_du_device *rcdu = rgrp->dev;
313 	u32 doflr = DOFLR_CODE;
314 	unsigned int i;
315 
316 	if (rcdu->info->gen < 2)
317 		return;
318 
319 	/*
320 	 * The DPAD outputs can't be controlled directly. However, the parallel
321 	 * output of the DU channels routed to DPAD can be set to fixed levels
322 	 * through the DOFLR group register. Use this to turn the DPAD on or off
323 	 * by driving fixed low-level signals at the output of any DU channel
324 	 * not routed to a DPAD output. This doesn't affect the DU output
325 	 * signals going to other outputs, such as the internal LVDS and HDMI
326 	 * encoders.
327 	 */
328 
329 	for (i = 0; i < rgrp->num_crtcs; ++i) {
330 		struct rcar_du_crtc_state *rstate;
331 		struct rcar_du_crtc *rcrtc;
332 
333 		rcrtc = &rcdu->crtcs[rgrp->index * 2 + i];
334 		rstate = to_rcar_crtc_state(rcrtc->crtc.state);
335 
336 		if (!(rstate->outputs & dpad_mask))
337 			doflr |= doflr_values[i];
338 	}
339 
340 	rcar_du_group_write(rgrp, DOFLR, doflr);
341 }
342 
rcar_du_group_set_routing(struct rcar_du_group * rgrp)343 int rcar_du_group_set_routing(struct rcar_du_group *rgrp)
344 {
345 	struct rcar_du_device *rcdu = rgrp->dev;
346 	u32 dorcr = rcar_du_group_read(rgrp, DORCR);
347 
348 	dorcr &= ~(DORCR_PG2T | DORCR_DK2S | DORCR_PG2D_MASK);
349 
350 	/*
351 	 * Set the DPAD1 pins sources. Select CRTC 0 if explicitly requested and
352 	 * CRTC 1 in all other cases to avoid cloning CRTC 0 to DPAD0 and DPAD1
353 	 * by default.
354 	 */
355 	if (rcdu->dpad1_source == rgrp->index * 2)
356 		dorcr |= DORCR_PG2D_DS1;
357 	else
358 		dorcr |= DORCR_PG2T | DORCR_DK2S | DORCR_PG2D_DS2;
359 
360 	rcar_du_group_write(rgrp, DORCR, dorcr);
361 
362 	rcar_du_group_set_dpad_levels(rgrp);
363 
364 	return rcar_du_set_dpad0_vsp1_routing(rgrp->dev);
365 }
366