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_LCDS_LVDS0(i)
126 			      |  DIDSR_PDCS_CLK(i, 0);
127 		else
128 			didsr |= DIDSR_LCDS_DCLKIN(i)
129 			      |  DIDSR_PDCS_CLK(i, 0);
130 	}
131 
132 	rcar_du_group_write(rgrp, DIDSR, didsr);
133 }
134 
rcar_du_group_setup(struct rcar_du_group * rgrp)135 static void rcar_du_group_setup(struct rcar_du_group *rgrp)
136 {
137 	struct rcar_du_device *rcdu = rgrp->dev;
138 
139 	/* Enable extended features */
140 	rcar_du_group_write(rgrp, DEFR, DEFR_CODE | DEFR_DEFE);
141 	if (rcdu->info->gen < 3) {
142 		rcar_du_group_write(rgrp, DEFR2, DEFR2_CODE | DEFR2_DEFE2G);
143 		rcar_du_group_write(rgrp, DEFR3, DEFR3_CODE | DEFR3_DEFE3);
144 		rcar_du_group_write(rgrp, DEFR4, DEFR4_CODE);
145 	}
146 	rcar_du_group_write(rgrp, DEFR5, DEFR5_CODE | DEFR5_DEFE5);
147 
148 	rcar_du_group_setup_pins(rgrp);
149 
150 	if (rcdu->info->gen >= 2) {
151 		rcar_du_group_setup_defr8(rgrp);
152 		rcar_du_group_setup_didsr(rgrp);
153 	}
154 
155 	if (rcdu->info->gen >= 3)
156 		rcar_du_group_write(rgrp, DEFR10, DEFR10_CODE | DEFR10_DEFE10);
157 
158 	/*
159 	 * Use DS1PR and DS2PR to configure planes priorities and connects the
160 	 * superposition 0 to DU0 pins. DU1 pins will be configured dynamically.
161 	 */
162 	rcar_du_group_write(rgrp, DORCR, DORCR_PG1D_DS1 | DORCR_DPRS);
163 
164 	/* Apply planes to CRTCs association. */
165 	mutex_lock(&rgrp->lock);
166 	rcar_du_group_write(rgrp, DPTSR, (rgrp->dptsr_planes << 16) |
167 			    rgrp->dptsr_planes);
168 	mutex_unlock(&rgrp->lock);
169 }
170 
171 /*
172  * rcar_du_group_get - Acquire a reference to the DU channels group
173  *
174  * Acquiring the first reference setups core registers. A reference must be held
175  * before accessing any hardware registers.
176  *
177  * This function must be called with the DRM mode_config lock held.
178  *
179  * Return 0 in case of success or a negative error code otherwise.
180  */
rcar_du_group_get(struct rcar_du_group * rgrp)181 int rcar_du_group_get(struct rcar_du_group *rgrp)
182 {
183 	if (rgrp->use_count)
184 		goto done;
185 
186 	rcar_du_group_setup(rgrp);
187 
188 done:
189 	rgrp->use_count++;
190 	return 0;
191 }
192 
193 /*
194  * rcar_du_group_put - Release a reference to the DU
195  *
196  * This function must be called with the DRM mode_config lock held.
197  */
rcar_du_group_put(struct rcar_du_group * rgrp)198 void rcar_du_group_put(struct rcar_du_group *rgrp)
199 {
200 	--rgrp->use_count;
201 }
202 
__rcar_du_group_start_stop(struct rcar_du_group * rgrp,bool start)203 static void __rcar_du_group_start_stop(struct rcar_du_group *rgrp, bool start)
204 {
205 	struct rcar_du_device *rcdu = rgrp->dev;
206 
207 	/*
208 	 * Group start/stop is controlled by the DRES and DEN bits of DSYSR0
209 	 * for the first group and DSYSR2 for the second group. On most DU
210 	 * instances, this maps to the first CRTC of the group, and we can just
211 	 * use rcar_du_crtc_dsysr_clr_set() to access the correct DSYSR. On
212 	 * M3-N, however, DU2 doesn't exist, but DSYSR2 does. We thus need to
213 	 * access the register directly using group read/write.
214 	 */
215 	if (rcdu->info->channels_mask & BIT(rgrp->index * 2)) {
216 		struct rcar_du_crtc *rcrtc = &rgrp->dev->crtcs[rgrp->index * 2];
217 
218 		rcar_du_crtc_dsysr_clr_set(rcrtc, DSYSR_DRES | DSYSR_DEN,
219 					   start ? DSYSR_DEN : DSYSR_DRES);
220 	} else {
221 		rcar_du_group_write(rgrp, DSYSR,
222 				    start ? DSYSR_DEN : DSYSR_DRES);
223 	}
224 }
225 
rcar_du_group_start_stop(struct rcar_du_group * rgrp,bool start)226 void rcar_du_group_start_stop(struct rcar_du_group *rgrp, bool start)
227 {
228 	/*
229 	 * Many of the configuration bits are only updated when the display
230 	 * reset (DRES) bit in DSYSR is set to 1, disabling *both* CRTCs. Some
231 	 * of those bits could be pre-configured, but others (especially the
232 	 * bits related to plane assignment to display timing controllers) need
233 	 * to be modified at runtime.
234 	 *
235 	 * Restart the display controller if a start is requested. Sorry for the
236 	 * flicker. It should be possible to move most of the "DRES-update" bits
237 	 * setup to driver initialization time and minimize the number of cases
238 	 * when the display controller will have to be restarted.
239 	 */
240 	if (start) {
241 		if (rgrp->used_crtcs++ != 0)
242 			__rcar_du_group_start_stop(rgrp, false);
243 		__rcar_du_group_start_stop(rgrp, true);
244 	} else {
245 		if (--rgrp->used_crtcs == 0)
246 			__rcar_du_group_start_stop(rgrp, false);
247 	}
248 }
249 
rcar_du_group_restart(struct rcar_du_group * rgrp)250 void rcar_du_group_restart(struct rcar_du_group *rgrp)
251 {
252 	rgrp->need_restart = false;
253 
254 	__rcar_du_group_start_stop(rgrp, false);
255 	__rcar_du_group_start_stop(rgrp, true);
256 }
257 
rcar_du_set_dpad0_vsp1_routing(struct rcar_du_device * rcdu)258 int rcar_du_set_dpad0_vsp1_routing(struct rcar_du_device *rcdu)
259 {
260 	struct rcar_du_group *rgrp;
261 	struct rcar_du_crtc *crtc;
262 	unsigned int index;
263 	int ret;
264 
265 	if (rcdu->info->gen < 2)
266 		return 0;
267 
268 	/*
269 	 * RGB output routing to DPAD0 and VSP1D routing to DU0/1/2 are
270 	 * configured in the DEFR8 register of the first group on Gen2 and the
271 	 * last group on Gen3. As this function can be called with the DU
272 	 * channels of the corresponding CRTCs disabled, we need to enable the
273 	 * group clock before accessing the register.
274 	 */
275 	index = rcdu->info->gen < 3 ? 0 : DIV_ROUND_UP(rcdu->num_crtcs, 2) - 1;
276 	rgrp = &rcdu->groups[index];
277 	crtc = &rcdu->crtcs[index * 2];
278 
279 	ret = clk_prepare_enable(crtc->clock);
280 	if (ret < 0)
281 		return ret;
282 
283 	rcar_du_group_setup_defr8(rgrp);
284 
285 	clk_disable_unprepare(crtc->clock);
286 
287 	return 0;
288 }
289 
rcar_du_group_set_dpad_levels(struct rcar_du_group * rgrp)290 static void rcar_du_group_set_dpad_levels(struct rcar_du_group *rgrp)
291 {
292 	static const u32 doflr_values[2] = {
293 		DOFLR_HSYCFL0 | DOFLR_VSYCFL0 | DOFLR_ODDFL0 |
294 		DOFLR_DISPFL0 | DOFLR_CDEFL0  | DOFLR_RGBFL0,
295 		DOFLR_HSYCFL1 | DOFLR_VSYCFL1 | DOFLR_ODDFL1 |
296 		DOFLR_DISPFL1 | DOFLR_CDEFL1  | DOFLR_RGBFL1,
297 	};
298 	static const u32 dpad_mask = BIT(RCAR_DU_OUTPUT_DPAD1)
299 				   | BIT(RCAR_DU_OUTPUT_DPAD0);
300 	struct rcar_du_device *rcdu = rgrp->dev;
301 	u32 doflr = DOFLR_CODE;
302 	unsigned int i;
303 
304 	if (rcdu->info->gen < 2)
305 		return;
306 
307 	/*
308 	 * The DPAD outputs can't be controlled directly. However, the parallel
309 	 * output of the DU channels routed to DPAD can be set to fixed levels
310 	 * through the DOFLR group register. Use this to turn the DPAD on or off
311 	 * by driving fixed low-level signals at the output of any DU channel
312 	 * not routed to a DPAD output. This doesn't affect the DU output
313 	 * signals going to other outputs, such as the internal LVDS and HDMI
314 	 * encoders.
315 	 */
316 
317 	for (i = 0; i < rgrp->num_crtcs; ++i) {
318 		struct rcar_du_crtc_state *rstate;
319 		struct rcar_du_crtc *rcrtc;
320 
321 		rcrtc = &rcdu->crtcs[rgrp->index * 2 + i];
322 		rstate = to_rcar_crtc_state(rcrtc->crtc.state);
323 
324 		if (!(rstate->outputs & dpad_mask))
325 			doflr |= doflr_values[i];
326 	}
327 
328 	rcar_du_group_write(rgrp, DOFLR, doflr);
329 }
330 
rcar_du_group_set_routing(struct rcar_du_group * rgrp)331 int rcar_du_group_set_routing(struct rcar_du_group *rgrp)
332 {
333 	struct rcar_du_device *rcdu = rgrp->dev;
334 	u32 dorcr = rcar_du_group_read(rgrp, DORCR);
335 
336 	dorcr &= ~(DORCR_PG2T | DORCR_DK2S | DORCR_PG2D_MASK);
337 
338 	/*
339 	 * Set the DPAD1 pins sources. Select CRTC 0 if explicitly requested and
340 	 * CRTC 1 in all other cases to avoid cloning CRTC 0 to DPAD0 and DPAD1
341 	 * by default.
342 	 */
343 	if (rcdu->dpad1_source == rgrp->index * 2)
344 		dorcr |= DORCR_PG2D_DS1;
345 	else
346 		dorcr |= DORCR_PG2T | DORCR_DK2S | DORCR_PG2D_DS2;
347 
348 	rcar_du_group_write(rgrp, DORCR, dorcr);
349 
350 	rcar_du_group_set_dpad_levels(rgrp);
351 
352 	return rcar_du_set_dpad0_vsp1_routing(rgrp->dev);
353 }
354