xref: /openbmc/linux/drivers/gpu/drm/tegra/rgb.c (revision 8b036556)
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/drm_atomic_helper.h>
13 #include <drm/drm_panel.h>
14 
15 #include "drm.h"
16 #include "dc.h"
17 
18 struct tegra_rgb {
19 	struct tegra_output output;
20 	struct tegra_dc *dc;
21 	bool enabled;
22 
23 	struct clk *clk_parent;
24 	struct clk *clk;
25 };
26 
27 static inline struct tegra_rgb *to_rgb(struct tegra_output *output)
28 {
29 	return container_of(output, struct tegra_rgb, output);
30 }
31 
32 struct reg_entry {
33 	unsigned long offset;
34 	unsigned long value;
35 };
36 
37 static const struct reg_entry rgb_enable[] = {
38 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x00000000 },
39 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x00000000 },
40 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x00000000 },
41 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x00000000 },
42 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
43 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x01000000 },
44 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
45 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
46 	{ DC_COM_PIN_OUTPUT_DATA(0),     0x00000000 },
47 	{ DC_COM_PIN_OUTPUT_DATA(1),     0x00000000 },
48 	{ DC_COM_PIN_OUTPUT_DATA(2),     0x00000000 },
49 	{ DC_COM_PIN_OUTPUT_DATA(3),     0x00000000 },
50 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
51 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
52 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
53 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
54 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00210222 },
55 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00002200 },
56 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00020000 },
57 };
58 
59 static const struct reg_entry rgb_disable[] = {
60 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00000000 },
61 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00000000 },
62 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00000000 },
63 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
64 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
65 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
66 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
67 	{ DC_COM_PIN_OUTPUT_DATA(3),     0xaaaaaaaa },
68 	{ DC_COM_PIN_OUTPUT_DATA(2),     0xaaaaaaaa },
69 	{ DC_COM_PIN_OUTPUT_DATA(1),     0xaaaaaaaa },
70 	{ DC_COM_PIN_OUTPUT_DATA(0),     0xaaaaaaaa },
71 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
72 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
73 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x00000000 },
74 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
75 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x55555555 },
76 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x55555555 },
77 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x55150005 },
78 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x55555555 },
79 };
80 
81 static void tegra_dc_write_regs(struct tegra_dc *dc,
82 				const struct reg_entry *table,
83 				unsigned int num)
84 {
85 	unsigned int i;
86 
87 	for (i = 0; i < num; i++)
88 		tegra_dc_writel(dc, table[i].value, table[i].offset);
89 }
90 
91 static void tegra_rgb_connector_dpms(struct drm_connector *connector,
92 				     int mode)
93 {
94 }
95 
96 static const struct drm_connector_funcs tegra_rgb_connector_funcs = {
97 	.dpms = tegra_rgb_connector_dpms,
98 	.reset = drm_atomic_helper_connector_reset,
99 	.detect = tegra_output_connector_detect,
100 	.fill_modes = drm_helper_probe_single_connector_modes,
101 	.destroy = tegra_output_connector_destroy,
102 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
103 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
104 };
105 
106 static enum drm_mode_status
107 tegra_rgb_connector_mode_valid(struct drm_connector *connector,
108 			       struct drm_display_mode *mode)
109 {
110 	/*
111 	 * FIXME: For now, always assume that the mode is okay. There are
112 	 * unresolved issues with clk_round_rate(), which doesn't always
113 	 * reliably report whether a frequency can be set or not.
114 	 */
115 	return MODE_OK;
116 }
117 
118 static const struct drm_connector_helper_funcs tegra_rgb_connector_helper_funcs = {
119 	.get_modes = tegra_output_connector_get_modes,
120 	.mode_valid = tegra_rgb_connector_mode_valid,
121 	.best_encoder = tegra_output_connector_best_encoder,
122 };
123 
124 static const struct drm_encoder_funcs tegra_rgb_encoder_funcs = {
125 	.destroy = tegra_output_encoder_destroy,
126 };
127 
128 static void tegra_rgb_encoder_dpms(struct drm_encoder *encoder, int mode)
129 {
130 }
131 
132 static void tegra_rgb_encoder_prepare(struct drm_encoder *encoder)
133 {
134 }
135 
136 static void tegra_rgb_encoder_commit(struct drm_encoder *encoder)
137 {
138 }
139 
140 static void tegra_rgb_encoder_mode_set(struct drm_encoder *encoder,
141 				       struct drm_display_mode *mode,
142 				       struct drm_display_mode *adjusted)
143 {
144 	struct tegra_output *output = encoder_to_output(encoder);
145 	struct tegra_rgb *rgb = to_rgb(output);
146 	u32 value;
147 
148 	if (output->panel)
149 		drm_panel_prepare(output->panel);
150 
151 	tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
152 
153 	value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
154 	tegra_dc_writel(rgb->dc, value, DC_DISP_DATA_ENABLE_OPTIONS);
155 
156 	/* XXX: parameterize? */
157 	value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(1));
158 	value &= ~LVS_OUTPUT_POLARITY_LOW;
159 	value &= ~LHS_OUTPUT_POLARITY_LOW;
160 	tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(1));
161 
162 	/* XXX: parameterize? */
163 	value = DISP_DATA_FORMAT_DF1P1C | DISP_ALIGNMENT_MSB |
164 		DISP_ORDER_RED_BLUE;
165 	tegra_dc_writel(rgb->dc, value, DC_DISP_DISP_INTERFACE_CONTROL);
166 
167 	/* XXX: parameterize? */
168 	value = SC0_H_QUALIFIER_NONE | SC1_H_QUALIFIER_NONE;
169 	tegra_dc_writel(rgb->dc, value, DC_DISP_SHIFT_CLOCK_OPTIONS);
170 
171 	tegra_dc_commit(rgb->dc);
172 
173 	if (output->panel)
174 		drm_panel_enable(output->panel);
175 }
176 
177 static void tegra_rgb_encoder_disable(struct drm_encoder *encoder)
178 {
179 	struct tegra_output *output = encoder_to_output(encoder);
180 	struct tegra_rgb *rgb = to_rgb(output);
181 
182 	if (output->panel)
183 		drm_panel_disable(output->panel);
184 
185 	tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
186 	tegra_dc_commit(rgb->dc);
187 
188 	if (output->panel)
189 		drm_panel_unprepare(output->panel);
190 }
191 
192 static int
193 tegra_rgb_encoder_atomic_check(struct drm_encoder *encoder,
194 			       struct drm_crtc_state *crtc_state,
195 			       struct drm_connector_state *conn_state)
196 {
197 	struct tegra_output *output = encoder_to_output(encoder);
198 	struct tegra_dc *dc = to_tegra_dc(conn_state->crtc);
199 	unsigned long pclk = crtc_state->mode.clock * 1000;
200 	struct tegra_rgb *rgb = to_rgb(output);
201 	unsigned int div;
202 	int err;
203 
204 	/*
205 	 * We may not want to change the frequency of the parent clock, since
206 	 * it may be a parent for other peripherals. This is due to the fact
207 	 * that on Tegra20 there's only a single clock dedicated to display
208 	 * (pll_d_out0), whereas later generations have a second one that can
209 	 * be used to independently drive a second output (pll_d2_out0).
210 	 *
211 	 * As a way to support multiple outputs on Tegra20 as well, pll_p is
212 	 * typically used as the parent clock for the display controllers.
213 	 * But this comes at a cost: pll_p is the parent of several other
214 	 * peripherals, so its frequency shouldn't change out of the blue.
215 	 *
216 	 * The best we can do at this point is to use the shift clock divider
217 	 * and hope that the desired frequency can be matched (or at least
218 	 * matched sufficiently close that the panel will still work).
219 	 */
220 	div = ((clk_get_rate(rgb->clk) * 2) / pclk) - 2;
221 	pclk = 0;
222 
223 	err = tegra_dc_state_setup_clock(dc, crtc_state, rgb->clk_parent,
224 					 pclk, div);
225 	if (err < 0) {
226 		dev_err(output->dev, "failed to setup CRTC state: %d\n", err);
227 		return err;
228 	}
229 
230 	return err;
231 }
232 
233 static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = {
234 	.dpms = tegra_rgb_encoder_dpms,
235 	.prepare = tegra_rgb_encoder_prepare,
236 	.commit = tegra_rgb_encoder_commit,
237 	.mode_set = tegra_rgb_encoder_mode_set,
238 	.disable = tegra_rgb_encoder_disable,
239 	.atomic_check = tegra_rgb_encoder_atomic_check,
240 };
241 
242 int tegra_dc_rgb_probe(struct tegra_dc *dc)
243 {
244 	struct device_node *np;
245 	struct tegra_rgb *rgb;
246 	int err;
247 
248 	np = of_get_child_by_name(dc->dev->of_node, "rgb");
249 	if (!np || !of_device_is_available(np))
250 		return -ENODEV;
251 
252 	rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
253 	if (!rgb)
254 		return -ENOMEM;
255 
256 	rgb->output.dev = dc->dev;
257 	rgb->output.of_node = np;
258 	rgb->dc = dc;
259 
260 	err = tegra_output_probe(&rgb->output);
261 	if (err < 0)
262 		return err;
263 
264 	rgb->clk = devm_clk_get(dc->dev, NULL);
265 	if (IS_ERR(rgb->clk)) {
266 		dev_err(dc->dev, "failed to get clock\n");
267 		return PTR_ERR(rgb->clk);
268 	}
269 
270 	rgb->clk_parent = devm_clk_get(dc->dev, "parent");
271 	if (IS_ERR(rgb->clk_parent)) {
272 		dev_err(dc->dev, "failed to get parent clock\n");
273 		return PTR_ERR(rgb->clk_parent);
274 	}
275 
276 	err = clk_set_parent(rgb->clk, rgb->clk_parent);
277 	if (err < 0) {
278 		dev_err(dc->dev, "failed to set parent clock: %d\n", err);
279 		return err;
280 	}
281 
282 	dc->rgb = &rgb->output;
283 
284 	return 0;
285 }
286 
287 int tegra_dc_rgb_remove(struct tegra_dc *dc)
288 {
289 	if (!dc->rgb)
290 		return 0;
291 
292 	tegra_output_remove(dc->rgb);
293 	dc->rgb = NULL;
294 
295 	return 0;
296 }
297 
298 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
299 {
300 	struct tegra_output *output = dc->rgb;
301 	int err;
302 
303 	if (!dc->rgb)
304 		return -ENODEV;
305 
306 	drm_connector_init(drm, &output->connector, &tegra_rgb_connector_funcs,
307 			   DRM_MODE_CONNECTOR_LVDS);
308 	drm_connector_helper_add(&output->connector,
309 				 &tegra_rgb_connector_helper_funcs);
310 	output->connector.dpms = DRM_MODE_DPMS_OFF;
311 
312 	drm_encoder_init(drm, &output->encoder, &tegra_rgb_encoder_funcs,
313 			 DRM_MODE_ENCODER_LVDS);
314 	drm_encoder_helper_add(&output->encoder,
315 			       &tegra_rgb_encoder_helper_funcs);
316 
317 	drm_mode_connector_attach_encoder(&output->connector,
318 					  &output->encoder);
319 	drm_connector_register(&output->connector);
320 
321 	err = tegra_output_init(drm, output);
322 	if (err < 0) {
323 		dev_err(output->dev, "failed to initialize output: %d\n", err);
324 		return err;
325 	}
326 
327 	/*
328 	 * Other outputs can be attached to either display controller. The RGB
329 	 * outputs are an exception and work only with their parent display
330 	 * controller.
331 	 */
332 	output->encoder.possible_crtcs = drm_crtc_mask(&dc->base);
333 
334 	return 0;
335 }
336 
337 int tegra_dc_rgb_exit(struct tegra_dc *dc)
338 {
339 	if (dc->rgb)
340 		tegra_output_exit(dc->rgb);
341 
342 	return 0;
343 }
344