xref: /openbmc/linux/drivers/gpu/drm/meson/meson_vclk.c (revision 7bcae826)
1 /*
2  * Copyright (C) 2016 BayLibre, SAS
3  * Author: Neil Armstrong <narmstrong@baylibre.com>
4  * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 of the
9  * License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <drm/drmP.h>
23 #include "meson_drv.h"
24 #include "meson_vclk.h"
25 
26 /*
27  * VCLK is the "Pixel Clock" frequency generator from a dedicated PLL.
28  * We handle the following encodings :
29  * - CVBS 27MHz generator via the VCLK2 to the VENCI and VDAC blocks
30  *
31  * What is missing :
32  * - HDMI Pixel Clocks generation
33  */
34 
35 /* HHI Registers */
36 #define HHI_VID_PLL_CLK_DIV	0x1a0 /* 0x68 offset in data sheet */
37 #define VID_PLL_EN		BIT(19)
38 #define VID_PLL_BYPASS		BIT(18)
39 #define VID_PLL_PRESET		BIT(15)
40 #define HHI_VIID_CLK_DIV	0x128 /* 0x4a offset in data sheet */
41 #define VCLK2_DIV_MASK		0xff
42 #define VCLK2_DIV_EN		BIT(16)
43 #define VCLK2_DIV_RESET		BIT(17)
44 #define CTS_VDAC_SEL_MASK	(0xf << 28)
45 #define CTS_VDAC_SEL_SHIFT	28
46 #define HHI_VIID_CLK_CNTL	0x12c /* 0x4b offset in data sheet */
47 #define VCLK2_EN		BIT(19)
48 #define VCLK2_SEL_MASK		(0x7 << 16)
49 #define VCLK2_SEL_SHIFT		16
50 #define VCLK2_SOFT_RESET	BIT(15)
51 #define VCLK2_DIV1_EN		BIT(0)
52 #define HHI_VID_CLK_DIV		0x164 /* 0x59 offset in data sheet */
53 #define CTS_ENCI_SEL_MASK	(0xf << 28)
54 #define CTS_ENCI_SEL_SHIFT	28
55 #define HHI_VID_CLK_CNTL2	0x194 /* 0x65 offset in data sheet */
56 #define CTS_ENCI_EN		BIT(0)
57 #define CTS_VDAC_EN		BIT(4)
58 
59 #define HHI_VDAC_CNTL0		0x2F4 /* 0xbd offset in data sheet */
60 #define HHI_VDAC_CNTL1		0x2F8 /* 0xbe offset in data sheet */
61 
62 #define HHI_HDMI_PLL_CNTL	0x320 /* 0xc8 offset in data sheet */
63 #define HHI_HDMI_PLL_CNTL2	0x324 /* 0xc9 offset in data sheet */
64 #define HHI_HDMI_PLL_CNTL3	0x328 /* 0xca offset in data sheet */
65 #define HHI_HDMI_PLL_CNTL4	0x32C /* 0xcb offset in data sheet */
66 #define HHI_HDMI_PLL_CNTL5	0x330 /* 0xcc offset in data sheet */
67 #define HHI_HDMI_PLL_CNTL6	0x334 /* 0xcd offset in data sheet */
68 
69 #define HDMI_PLL_RESET		BIT(28)
70 #define HDMI_PLL_LOCK		BIT(31)
71 
72 /*
73  * Setup VCLK2 for 27MHz, and enable clocks for ENCI and VDAC
74  *
75  * TOFIX: Refactor into table to also handle HDMI frequency and paths
76  */
77 static void meson_venci_cvbs_clock_config(struct meson_drm *priv)
78 {
79 	unsigned int val;
80 
81 	/* Setup PLL to output 1.485GHz */
82 	if (meson_vpu_is_compatible(priv, "amlogic,meson-gxbb-vpu")) {
83 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL, 0x5800023d);
84 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL2, 0x00404e00);
85 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL3, 0x0d5c5091);
86 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL4, 0x801da72c);
87 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL5, 0x71486980);
88 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL6, 0x00000e55);
89 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL, 0x4800023d);
90 	} else if (meson_vpu_is_compatible(priv, "amlogic,meson-gxm-vpu") ||
91 		   meson_vpu_is_compatible(priv, "amlogic,meson-gxl-vpu")) {
92 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL, 0x4000027b);
93 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL2, 0x800cb300);
94 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL3, 0xa6212844);
95 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL4, 0x0c4d000c);
96 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL5, 0x001fa729);
97 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL6, 0x01a31500);
98 
99 		/* Reset PLL */
100 		regmap_update_bits(priv->hhi, HHI_HDMI_PLL_CNTL,
101 					HDMI_PLL_RESET, HDMI_PLL_RESET);
102 		regmap_update_bits(priv->hhi, HHI_HDMI_PLL_CNTL,
103 					HDMI_PLL_RESET, 0);
104 	}
105 
106 	/* Poll for lock bit */
107 	regmap_read_poll_timeout(priv->hhi, HHI_HDMI_PLL_CNTL, val,
108 				 (val & HDMI_PLL_LOCK), 10, 0);
109 
110 	/* Disable VCLK2 */
111 	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL, VCLK2_EN, 0);
112 
113 	/* Disable vid_pll output clock */
114 	regmap_update_bits(priv->hhi, HHI_VID_PLL_CLK_DIV, VID_PLL_EN, 0);
115 	regmap_update_bits(priv->hhi, HHI_VID_PLL_CLK_DIV, VID_PLL_PRESET, 0);
116 	/* Enable vid_pll bypass to HDMI pll */
117 	regmap_update_bits(priv->hhi, HHI_VID_PLL_CLK_DIV,
118 				VID_PLL_BYPASS, VID_PLL_BYPASS);
119 	/* Enable the vid_pll output clock */
120 	regmap_update_bits(priv->hhi, HHI_VID_PLL_CLK_DIV,
121 				VID_PLL_EN, VID_PLL_EN);
122 
123 	/* Setup the VCLK2 divider value to achieve 27MHz */
124 	regmap_update_bits(priv->hhi, HHI_VIID_CLK_DIV,
125 				VCLK2_DIV_MASK, (55 - 1));
126 
127 	/* select vid_pll for vclk2 */
128 	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL,
129 				VCLK2_SEL_MASK, (4 << VCLK2_SEL_SHIFT));
130 	/* enable vclk2 gate */
131 	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL, VCLK2_EN, VCLK2_EN);
132 
133 	/* select vclk_div1 for enci */
134 	regmap_update_bits(priv->hhi, HHI_VID_CLK_DIV,
135 				CTS_ENCI_SEL_MASK, (8 << CTS_ENCI_SEL_SHIFT));
136 	/* select vclk_div1 for vdac */
137 	regmap_update_bits(priv->hhi, HHI_VIID_CLK_DIV,
138 				CTS_VDAC_SEL_MASK, (8 << CTS_VDAC_SEL_SHIFT));
139 
140 	/* release vclk2_div_reset and enable vclk2_div */
141 	regmap_update_bits(priv->hhi, HHI_VIID_CLK_DIV,
142 				VCLK2_DIV_EN | VCLK2_DIV_RESET, VCLK2_DIV_EN);
143 
144 	/* enable vclk2_div1 gate */
145 	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL,
146 				VCLK2_DIV1_EN, VCLK2_DIV1_EN);
147 
148 	/* reset vclk2 */
149 	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL,
150 				VCLK2_SOFT_RESET, VCLK2_SOFT_RESET);
151 	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL,
152 				VCLK2_SOFT_RESET, 0);
153 
154 	/* enable enci_clk */
155 	regmap_update_bits(priv->hhi, HHI_VID_CLK_CNTL2,
156 				CTS_ENCI_EN, CTS_ENCI_EN);
157 	/* enable vdac_clk */
158 	regmap_update_bits(priv->hhi, HHI_VID_CLK_CNTL2,
159 				CTS_VDAC_EN, CTS_VDAC_EN);
160 }
161 
162 void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
163 		      unsigned int freq)
164 {
165 	if (target == MESON_VCLK_TARGET_CVBS && freq == MESON_VCLK_CVBS)
166 		meson_venci_cvbs_clock_config(priv);
167 }
168