xref: /openbmc/linux/drivers/gpu/drm/tegra/rgb.c (revision 455f9726)
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 tegra_dc *dc;
18 	bool enabled;
19 
20 	struct clk *clk_parent;
21 	struct clk *clk;
22 };
23 
24 static inline struct tegra_rgb *to_rgb(struct tegra_output *output)
25 {
26 	return container_of(output, struct tegra_rgb, output);
27 }
28 
29 struct reg_entry {
30 	unsigned long offset;
31 	unsigned long value;
32 };
33 
34 static const struct reg_entry rgb_enable[] = {
35 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x00000000 },
36 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x00000000 },
37 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x00000000 },
38 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x00000000 },
39 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
40 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x01000000 },
41 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
42 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
43 	{ DC_COM_PIN_OUTPUT_DATA(0),     0x00000000 },
44 	{ DC_COM_PIN_OUTPUT_DATA(1),     0x00000000 },
45 	{ DC_COM_PIN_OUTPUT_DATA(2),     0x00000000 },
46 	{ DC_COM_PIN_OUTPUT_DATA(3),     0x00000000 },
47 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
48 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
49 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
50 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
51 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00210222 },
52 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00002200 },
53 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00020000 },
54 };
55 
56 static const struct reg_entry rgb_disable[] = {
57 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00000000 },
58 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00000000 },
59 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00000000 },
60 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
61 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
62 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
63 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
64 	{ DC_COM_PIN_OUTPUT_DATA(3),     0xaaaaaaaa },
65 	{ DC_COM_PIN_OUTPUT_DATA(2),     0xaaaaaaaa },
66 	{ DC_COM_PIN_OUTPUT_DATA(1),     0xaaaaaaaa },
67 	{ DC_COM_PIN_OUTPUT_DATA(0),     0xaaaaaaaa },
68 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
69 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
70 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x00000000 },
71 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
72 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x55555555 },
73 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x55555555 },
74 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x55150005 },
75 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x55555555 },
76 };
77 
78 static void tegra_dc_write_regs(struct tegra_dc *dc,
79 				const struct reg_entry *table,
80 				unsigned int num)
81 {
82 	unsigned int i;
83 
84 	for (i = 0; i < num; i++)
85 		tegra_dc_writel(dc, table[i].value, table[i].offset);
86 }
87 
88 static int tegra_output_rgb_enable(struct tegra_output *output)
89 {
90 	struct tegra_rgb *rgb = to_rgb(output);
91 	unsigned long value;
92 
93 	if (rgb->enabled)
94 		return 0;
95 
96 	tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
97 
98 	value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
99 	tegra_dc_writel(rgb->dc, value, DC_DISP_DATA_ENABLE_OPTIONS);
100 
101 	/* XXX: parameterize? */
102 	value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(1));
103 	value &= ~LVS_OUTPUT_POLARITY_LOW;
104 	value &= ~LHS_OUTPUT_POLARITY_LOW;
105 	tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(1));
106 
107 	/* XXX: parameterize? */
108 	value = DISP_DATA_FORMAT_DF1P1C | DISP_ALIGNMENT_MSB |
109 		DISP_ORDER_RED_BLUE;
110 	tegra_dc_writel(rgb->dc, value, DC_DISP_DISP_INTERFACE_CONTROL);
111 
112 	/* XXX: parameterize? */
113 	value = SC0_H_QUALIFIER_NONE | SC1_H_QUALIFIER_NONE;
114 	tegra_dc_writel(rgb->dc, value, DC_DISP_SHIFT_CLOCK_OPTIONS);
115 
116 	value = tegra_dc_readl(rgb->dc, DC_CMD_DISPLAY_COMMAND);
117 	value &= ~DISP_CTRL_MODE_MASK;
118 	value |= DISP_CTRL_MODE_C_DISPLAY;
119 	tegra_dc_writel(rgb->dc, value, DC_CMD_DISPLAY_COMMAND);
120 
121 	value = tegra_dc_readl(rgb->dc, DC_CMD_DISPLAY_POWER_CONTROL);
122 	value |= PW0_ENABLE | PW1_ENABLE | PW2_ENABLE | PW3_ENABLE |
123 		 PW4_ENABLE | PM0_ENABLE | PM1_ENABLE;
124 	tegra_dc_writel(rgb->dc, value, DC_CMD_DISPLAY_POWER_CONTROL);
125 
126 	tegra_dc_writel(rgb->dc, GENERAL_ACT_REQ << 8, DC_CMD_STATE_CONTROL);
127 	tegra_dc_writel(rgb->dc, GENERAL_ACT_REQ, DC_CMD_STATE_CONTROL);
128 
129 	rgb->enabled = true;
130 
131 	return 0;
132 }
133 
134 static int tegra_output_rgb_disable(struct tegra_output *output)
135 {
136 	struct tegra_rgb *rgb = to_rgb(output);
137 	unsigned long value;
138 
139 	if (!rgb->enabled)
140 		return 0;
141 
142 	value = tegra_dc_readl(rgb->dc, DC_CMD_DISPLAY_POWER_CONTROL);
143 	value &= ~(PW0_ENABLE | PW1_ENABLE | PW2_ENABLE | PW3_ENABLE |
144 		   PW4_ENABLE | PM0_ENABLE | PM1_ENABLE);
145 	tegra_dc_writel(rgb->dc, value, DC_CMD_DISPLAY_POWER_CONTROL);
146 
147 	value = tegra_dc_readl(rgb->dc, DC_CMD_DISPLAY_COMMAND);
148 	value &= ~DISP_CTRL_MODE_MASK;
149 	tegra_dc_writel(rgb->dc, value, DC_CMD_DISPLAY_COMMAND);
150 
151 	tegra_dc_writel(rgb->dc, GENERAL_ACT_REQ << 8, DC_CMD_STATE_CONTROL);
152 	tegra_dc_writel(rgb->dc, GENERAL_ACT_REQ, DC_CMD_STATE_CONTROL);
153 
154 	tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
155 
156 	rgb->enabled = false;
157 
158 	return 0;
159 }
160 
161 static int tegra_output_rgb_setup_clock(struct tegra_output *output,
162 					struct clk *clk, unsigned long pclk,
163 					unsigned int *div)
164 {
165 	struct tegra_rgb *rgb = to_rgb(output);
166 	int err;
167 
168 	err = clk_set_parent(clk, rgb->clk_parent);
169 	if (err < 0) {
170 		dev_err(output->dev, "failed to set parent: %d\n", err);
171 		return err;
172 	}
173 
174 	/*
175 	 * We may not want to change the frequency of the parent clock, since
176 	 * it may be a parent for other peripherals. This is due to the fact
177 	 * that on Tegra20 there's only a single clock dedicated to display
178 	 * (pll_d_out0), whereas later generations have a second one that can
179 	 * be used to independently drive a second output (pll_d2_out0).
180 	 *
181 	 * As a way to support multiple outputs on Tegra20 as well, pll_p is
182 	 * typically used as the parent clock for the display controllers.
183 	 * But this comes at a cost: pll_p is the parent of several other
184 	 * peripherals, so its frequency shouldn't change out of the blue.
185 	 *
186 	 * The best we can do at this point is to use the shift clock divider
187 	 * and hope that the desired frequency can be matched (or at least
188 	 * matched sufficiently close that the panel will still work).
189 	 */
190 
191 	*div = ((clk_get_rate(clk) * 2) / pclk) - 2;
192 
193 	return 0;
194 }
195 
196 static int tegra_output_rgb_check_mode(struct tegra_output *output,
197 				       struct drm_display_mode *mode,
198 				       enum drm_mode_status *status)
199 {
200 	/*
201 	 * FIXME: For now, always assume that the mode is okay. There are
202 	 * unresolved issues with clk_round_rate(), which doesn't always
203 	 * reliably report whether a frequency can be set or not.
204 	 */
205 
206 	*status = MODE_OK;
207 
208 	return 0;
209 }
210 
211 static const struct tegra_output_ops rgb_ops = {
212 	.enable = tegra_output_rgb_enable,
213 	.disable = tegra_output_rgb_disable,
214 	.setup_clock = tegra_output_rgb_setup_clock,
215 	.check_mode = tegra_output_rgb_check_mode,
216 };
217 
218 int tegra_dc_rgb_probe(struct tegra_dc *dc)
219 {
220 	struct device_node *np;
221 	struct tegra_rgb *rgb;
222 	int err;
223 
224 	np = of_get_child_by_name(dc->dev->of_node, "rgb");
225 	if (!np || !of_device_is_available(np))
226 		return -ENODEV;
227 
228 	rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
229 	if (!rgb)
230 		return -ENOMEM;
231 
232 	rgb->output.dev = dc->dev;
233 	rgb->output.of_node = np;
234 	rgb->dc = dc;
235 
236 	err = tegra_output_probe(&rgb->output);
237 	if (err < 0)
238 		return err;
239 
240 	rgb->clk = devm_clk_get(dc->dev, NULL);
241 	if (IS_ERR(rgb->clk)) {
242 		dev_err(dc->dev, "failed to get clock\n");
243 		return PTR_ERR(rgb->clk);
244 	}
245 
246 	rgb->clk_parent = devm_clk_get(dc->dev, "parent");
247 	if (IS_ERR(rgb->clk_parent)) {
248 		dev_err(dc->dev, "failed to get parent clock\n");
249 		return PTR_ERR(rgb->clk_parent);
250 	}
251 
252 	err = clk_set_parent(rgb->clk, rgb->clk_parent);
253 	if (err < 0) {
254 		dev_err(dc->dev, "failed to set parent clock: %d\n", err);
255 		return err;
256 	}
257 
258 	dc->rgb = &rgb->output;
259 
260 	return 0;
261 }
262 
263 int tegra_dc_rgb_remove(struct tegra_dc *dc)
264 {
265 	int err;
266 
267 	if (!dc->rgb)
268 		return 0;
269 
270 	err = tegra_output_remove(dc->rgb);
271 	if (err < 0)
272 		return err;
273 
274 	return 0;
275 }
276 
277 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
278 {
279 	struct tegra_rgb *rgb = to_rgb(dc->rgb);
280 	int err;
281 
282 	if (!dc->rgb)
283 		return -ENODEV;
284 
285 	rgb->output.type = TEGRA_OUTPUT_RGB;
286 	rgb->output.ops = &rgb_ops;
287 
288 	err = tegra_output_init(dc->base.dev, &rgb->output);
289 	if (err < 0) {
290 		dev_err(dc->dev, "output setup failed: %d\n", err);
291 		return err;
292 	}
293 
294 	/*
295 	 * By default, outputs can be associated with each display controller.
296 	 * RGB outputs are an exception, so we make sure they can be attached
297 	 * to only their parent display controller.
298 	 */
299 	rgb->output.encoder.possible_crtcs = drm_crtc_mask(&dc->base);
300 
301 	return 0;
302 }
303 
304 int tegra_dc_rgb_exit(struct tegra_dc *dc)
305 {
306 	if (dc->rgb) {
307 		int err;
308 
309 		err = tegra_output_disable(dc->rgb);
310 		if (err < 0) {
311 			dev_err(dc->dev, "output failed to disable: %d\n", err);
312 			return err;
313 		}
314 
315 		err = tegra_output_exit(dc->rgb);
316 		if (err < 0) {
317 			dev_err(dc->dev, "output cleanup failed: %d\n", err);
318 			return err;
319 		}
320 
321 		dc->rgb = NULL;
322 	}
323 
324 	return 0;
325 }
326