xref: /openbmc/linux/drivers/gpu/drm/tegra/rgb.c (revision 79f08d9e)
1 /*
2  * Copyright (C) 2012 Avionic Design GmbH
3  * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #include <linux/clk.h>
11 
12 #include "drm.h"
13 #include "dc.h"
14 
15 struct tegra_rgb {
16 	struct tegra_output output;
17 	struct clk *clk_parent;
18 	struct clk *clk;
19 };
20 
21 static inline struct tegra_rgb *to_rgb(struct tegra_output *output)
22 {
23 	return container_of(output, struct tegra_rgb, output);
24 }
25 
26 struct reg_entry {
27 	unsigned long offset;
28 	unsigned long value;
29 };
30 
31 static const struct reg_entry rgb_enable[] = {
32 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x00000000 },
33 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x00000000 },
34 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x00000000 },
35 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x00000000 },
36 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
37 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x01000000 },
38 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
39 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
40 	{ DC_COM_PIN_OUTPUT_DATA(0),     0x00000000 },
41 	{ DC_COM_PIN_OUTPUT_DATA(1),     0x00000000 },
42 	{ DC_COM_PIN_OUTPUT_DATA(2),     0x00000000 },
43 	{ DC_COM_PIN_OUTPUT_DATA(3),     0x00000000 },
44 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
45 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
46 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
47 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
48 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00210222 },
49 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00002200 },
50 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00020000 },
51 };
52 
53 static const struct reg_entry rgb_disable[] = {
54 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00000000 },
55 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00000000 },
56 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00000000 },
57 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
58 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
59 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
60 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
61 	{ DC_COM_PIN_OUTPUT_DATA(3),     0xaaaaaaaa },
62 	{ DC_COM_PIN_OUTPUT_DATA(2),     0xaaaaaaaa },
63 	{ DC_COM_PIN_OUTPUT_DATA(1),     0xaaaaaaaa },
64 	{ DC_COM_PIN_OUTPUT_DATA(0),     0xaaaaaaaa },
65 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
66 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
67 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x00000000 },
68 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
69 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x55555555 },
70 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x55555555 },
71 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x55150005 },
72 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x55555555 },
73 };
74 
75 static void tegra_dc_write_regs(struct tegra_dc *dc,
76 				const struct reg_entry *table,
77 				unsigned int num)
78 {
79 	unsigned int i;
80 
81 	for (i = 0; i < num; i++)
82 		tegra_dc_writel(dc, table[i].value, table[i].offset);
83 }
84 
85 static int tegra_output_rgb_enable(struct tegra_output *output)
86 {
87 	struct tegra_dc *dc = to_tegra_dc(output->encoder.crtc);
88 
89 	tegra_dc_write_regs(dc, rgb_enable, ARRAY_SIZE(rgb_enable));
90 
91 	return 0;
92 }
93 
94 static int tegra_output_rgb_disable(struct tegra_output *output)
95 {
96 	struct tegra_dc *dc = to_tegra_dc(output->encoder.crtc);
97 
98 	tegra_dc_write_regs(dc, rgb_disable, ARRAY_SIZE(rgb_disable));
99 
100 	return 0;
101 }
102 
103 static int tegra_output_rgb_setup_clock(struct tegra_output *output,
104 					struct clk *clk, unsigned long pclk)
105 {
106 	struct tegra_rgb *rgb = to_rgb(output);
107 
108 	return clk_set_parent(clk, rgb->clk_parent);
109 }
110 
111 static int tegra_output_rgb_check_mode(struct tegra_output *output,
112 				       struct drm_display_mode *mode,
113 				       enum drm_mode_status *status)
114 {
115 	/*
116 	 * FIXME: For now, always assume that the mode is okay. There are
117 	 * unresolved issues with clk_round_rate(), which doesn't always
118 	 * reliably report whether a frequency can be set or not.
119 	 */
120 
121 	*status = MODE_OK;
122 
123 	return 0;
124 }
125 
126 static const struct tegra_output_ops rgb_ops = {
127 	.enable = tegra_output_rgb_enable,
128 	.disable = tegra_output_rgb_disable,
129 	.setup_clock = tegra_output_rgb_setup_clock,
130 	.check_mode = tegra_output_rgb_check_mode,
131 };
132 
133 int tegra_dc_rgb_probe(struct tegra_dc *dc)
134 {
135 	struct device_node *np;
136 	struct tegra_rgb *rgb;
137 	int err;
138 
139 	np = of_get_child_by_name(dc->dev->of_node, "rgb");
140 	if (!np || !of_device_is_available(np))
141 		return -ENODEV;
142 
143 	rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
144 	if (!rgb)
145 		return -ENOMEM;
146 
147 	rgb->output.dev = dc->dev;
148 	rgb->output.of_node = np;
149 
150 	err = tegra_output_probe(&rgb->output);
151 	if (err < 0)
152 		return err;
153 
154 	rgb->clk = devm_clk_get(dc->dev, NULL);
155 	if (IS_ERR(rgb->clk)) {
156 		dev_err(dc->dev, "failed to get clock\n");
157 		return PTR_ERR(rgb->clk);
158 	}
159 
160 	rgb->clk_parent = devm_clk_get(dc->dev, "parent");
161 	if (IS_ERR(rgb->clk_parent)) {
162 		dev_err(dc->dev, "failed to get parent clock\n");
163 		return PTR_ERR(rgb->clk_parent);
164 	}
165 
166 	err = clk_set_parent(rgb->clk, rgb->clk_parent);
167 	if (err < 0) {
168 		dev_err(dc->dev, "failed to set parent clock: %d\n", err);
169 		return err;
170 	}
171 
172 	dc->rgb = &rgb->output;
173 
174 	return 0;
175 }
176 
177 int tegra_dc_rgb_remove(struct tegra_dc *dc)
178 {
179 	int err;
180 
181 	if (!dc->rgb)
182 		return 0;
183 
184 	err = tegra_output_remove(dc->rgb);
185 	if (err < 0)
186 		return err;
187 
188 	return 0;
189 }
190 
191 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
192 {
193 	struct tegra_rgb *rgb = to_rgb(dc->rgb);
194 	int err;
195 
196 	if (!dc->rgb)
197 		return -ENODEV;
198 
199 	rgb->output.type = TEGRA_OUTPUT_RGB;
200 	rgb->output.ops = &rgb_ops;
201 
202 	err = tegra_output_init(dc->base.dev, &rgb->output);
203 	if (err < 0) {
204 		dev_err(dc->dev, "output setup failed: %d\n", err);
205 		return err;
206 	}
207 
208 	/*
209 	 * By default, outputs can be associated with each display controller.
210 	 * RGB outputs are an exception, so we make sure they can be attached
211 	 * to only their parent display controller.
212 	 */
213 	rgb->output.encoder.possible_crtcs = 1 << dc->pipe;
214 
215 	return 0;
216 }
217 
218 int tegra_dc_rgb_exit(struct tegra_dc *dc)
219 {
220 	if (dc->rgb) {
221 		int err;
222 
223 		err = tegra_output_disable(dc->rgb);
224 		if (err < 0) {
225 			dev_err(dc->dev, "output failed to disable: %d\n", err);
226 			return err;
227 		}
228 
229 		err = tegra_output_exit(dc->rgb);
230 		if (err < 0) {
231 			dev_err(dc->dev, "output cleanup failed: %d\n", err);
232 			return err;
233 		}
234 
235 		dc->rgb = NULL;
236 	}
237 
238 	return 0;
239 }
240