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1 /*
2  * rcar_du_group.c  --  R-Car Display Unit Channels Pair
3  *
4  * Copyright (C) 2013-2014 Renesas Electronics Corporation
5  *
6  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 
14 /*
15  * The R8A7779 DU is split in per-CRTC resources (scan-out engine, blending
16  * unit, timings generator, ...) and device-global resources (start/stop
17  * control, planes, ...) shared between the two CRTCs.
18  *
19  * The R8A7790 introduced a third CRTC with its own set of global resources.
20  * This would be modeled as two separate DU device instances if it wasn't for
21  * a handful or resources that are shared between the three CRTCs (mostly
22  * related to input and output routing). For this reason the R8A7790 DU must be
23  * modeled as a single device with three CRTCs, two sets of "semi-global"
24  * resources, and a few device-global resources.
25  *
26  * The rcar_du_group object is a driver specific object, without any real
27  * counterpart in the DU documentation, that models those semi-global resources.
28  */
29 
30 #include <linux/clk.h>
31 #include <linux/io.h>
32 
33 #include "rcar_du_drv.h"
34 #include "rcar_du_group.h"
35 #include "rcar_du_regs.h"
36 
rcar_du_group_read(struct rcar_du_group * rgrp,u32 reg)37 u32 rcar_du_group_read(struct rcar_du_group *rgrp, u32 reg)
38 {
39 	return rcar_du_read(rgrp->dev, rgrp->mmio_offset + reg);
40 }
41 
rcar_du_group_write(struct rcar_du_group * rgrp,u32 reg,u32 data)42 void rcar_du_group_write(struct rcar_du_group *rgrp, u32 reg, u32 data)
43 {
44 	rcar_du_write(rgrp->dev, rgrp->mmio_offset + reg, data);
45 }
46 
rcar_du_group_setup_defr8(struct rcar_du_group * rgrp)47 static void rcar_du_group_setup_defr8(struct rcar_du_group *rgrp)
48 {
49 	u32 defr8 = DEFR8_CODE | DEFR8_DEFE8;
50 
51 	if (!rcar_du_has(rgrp->dev, RCAR_DU_FEATURE_DEFR8))
52 		return;
53 
54 	/* The DEFR8 register for the first group also controls RGB output
55 	 * routing to DPAD0
56 	 */
57 	if (rgrp->index == 0)
58 		defr8 |= DEFR8_DRGBS_DU(rgrp->dev->dpad0_source);
59 
60 	rcar_du_group_write(rgrp, DEFR8, defr8);
61 }
62 
rcar_du_group_setup(struct rcar_du_group * rgrp)63 static void rcar_du_group_setup(struct rcar_du_group *rgrp)
64 {
65 	/* Enable extended features */
66 	rcar_du_group_write(rgrp, DEFR, DEFR_CODE | DEFR_DEFE);
67 	rcar_du_group_write(rgrp, DEFR2, DEFR2_CODE | DEFR2_DEFE2G);
68 	rcar_du_group_write(rgrp, DEFR3, DEFR3_CODE | DEFR3_DEFE3);
69 	rcar_du_group_write(rgrp, DEFR4, DEFR4_CODE);
70 	rcar_du_group_write(rgrp, DEFR5, DEFR5_CODE | DEFR5_DEFE5);
71 
72 	rcar_du_group_setup_defr8(rgrp);
73 
74 	/* Use DS1PR and DS2PR to configure planes priorities and connects the
75 	 * superposition 0 to DU0 pins. DU1 pins will be configured dynamically.
76 	 */
77 	rcar_du_group_write(rgrp, DORCR, DORCR_PG1D_DS1 | DORCR_DPRS);
78 }
79 
80 /*
81  * rcar_du_group_get - Acquire a reference to the DU channels group
82  *
83  * Acquiring the first reference setups core registers. A reference must be held
84  * before accessing any hardware registers.
85  *
86  * This function must be called with the DRM mode_config lock held.
87  *
88  * Return 0 in case of success or a negative error code otherwise.
89  */
rcar_du_group_get(struct rcar_du_group * rgrp)90 int rcar_du_group_get(struct rcar_du_group *rgrp)
91 {
92 	if (rgrp->use_count)
93 		goto done;
94 
95 	rcar_du_group_setup(rgrp);
96 
97 done:
98 	rgrp->use_count++;
99 	return 0;
100 }
101 
102 /*
103  * rcar_du_group_put - Release a reference to the DU
104  *
105  * This function must be called with the DRM mode_config lock held.
106  */
rcar_du_group_put(struct rcar_du_group * rgrp)107 void rcar_du_group_put(struct rcar_du_group *rgrp)
108 {
109 	--rgrp->use_count;
110 }
111 
__rcar_du_group_start_stop(struct rcar_du_group * rgrp,bool start)112 static void __rcar_du_group_start_stop(struct rcar_du_group *rgrp, bool start)
113 {
114 	rcar_du_group_write(rgrp, DSYSR,
115 		(rcar_du_group_read(rgrp, DSYSR) & ~(DSYSR_DRES | DSYSR_DEN)) |
116 		(start ? DSYSR_DEN : DSYSR_DRES));
117 }
118 
rcar_du_group_start_stop(struct rcar_du_group * rgrp,bool start)119 void rcar_du_group_start_stop(struct rcar_du_group *rgrp, bool start)
120 {
121 	/* Many of the configuration bits are only updated when the display
122 	 * reset (DRES) bit in DSYSR is set to 1, disabling *both* CRTCs. Some
123 	 * of those bits could be pre-configured, but others (especially the
124 	 * bits related to plane assignment to display timing controllers) need
125 	 * to be modified at runtime.
126 	 *
127 	 * Restart the display controller if a start is requested. Sorry for the
128 	 * flicker. It should be possible to move most of the "DRES-update" bits
129 	 * setup to driver initialization time and minimize the number of cases
130 	 * when the display controller will have to be restarted.
131 	 */
132 	if (start) {
133 		if (rgrp->used_crtcs++ != 0)
134 			__rcar_du_group_start_stop(rgrp, false);
135 		__rcar_du_group_start_stop(rgrp, true);
136 	} else {
137 		if (--rgrp->used_crtcs == 0)
138 			__rcar_du_group_start_stop(rgrp, false);
139 	}
140 }
141 
rcar_du_group_restart(struct rcar_du_group * rgrp)142 void rcar_du_group_restart(struct rcar_du_group *rgrp)
143 {
144 	__rcar_du_group_start_stop(rgrp, false);
145 	__rcar_du_group_start_stop(rgrp, true);
146 }
147 
rcar_du_set_dpad0_routing(struct rcar_du_device * rcdu)148 static int rcar_du_set_dpad0_routing(struct rcar_du_device *rcdu)
149 {
150 	int ret;
151 
152 	/* RGB output routing to DPAD0 is configured in the DEFR8 register of
153 	 * the first group. As this function can be called with the DU0 and DU1
154 	 * CRTCs disabled, we need to enable the first group clock before
155 	 * accessing the register.
156 	 */
157 	ret = clk_prepare_enable(rcdu->crtcs[0].clock);
158 	if (ret < 0)
159 		return ret;
160 
161 	rcar_du_group_setup_defr8(&rcdu->groups[0]);
162 
163 	clk_disable_unprepare(rcdu->crtcs[0].clock);
164 
165 	return 0;
166 }
167 
rcar_du_group_set_routing(struct rcar_du_group * rgrp)168 int rcar_du_group_set_routing(struct rcar_du_group *rgrp)
169 {
170 	struct rcar_du_crtc *crtc0 = &rgrp->dev->crtcs[rgrp->index * 2];
171 	u32 dorcr = rcar_du_group_read(rgrp, DORCR);
172 
173 	dorcr &= ~(DORCR_PG2T | DORCR_DK2S | DORCR_PG2D_MASK);
174 
175 	/* Set the DPAD1 pins sources. Select CRTC 0 if explicitly requested and
176 	 * CRTC 1 in all other cases to avoid cloning CRTC 0 to DPAD0 and DPAD1
177 	 * by default.
178 	 */
179 	if (crtc0->outputs & BIT(RCAR_DU_OUTPUT_DPAD1))
180 		dorcr |= DORCR_PG2D_DS1;
181 	else
182 		dorcr |= DORCR_PG2T | DORCR_DK2S | DORCR_PG2D_DS2;
183 
184 	rcar_du_group_write(rgrp, DORCR, dorcr);
185 
186 	return rcar_du_set_dpad0_routing(rgrp->dev);
187 }
188