xref: /openbmc/linux/drivers/gpu/drm/tegra/rgb.c (revision b96fc2f3)
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 
22 	struct clk *clk_parent;
23 	struct clk *clk;
24 };
25 
26 static inline struct tegra_rgb *to_rgb(struct tegra_output *output)
27 {
28 	return container_of(output, struct tegra_rgb, output);
29 }
30 
31 struct reg_entry {
32 	unsigned long offset;
33 	unsigned long value;
34 };
35 
36 static const struct reg_entry rgb_enable[] = {
37 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x00000000 },
38 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x00000000 },
39 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x00000000 },
40 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x00000000 },
41 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
42 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x01000000 },
43 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
44 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
45 	{ DC_COM_PIN_OUTPUT_DATA(0),     0x00000000 },
46 	{ DC_COM_PIN_OUTPUT_DATA(1),     0x00000000 },
47 	{ DC_COM_PIN_OUTPUT_DATA(2),     0x00000000 },
48 	{ DC_COM_PIN_OUTPUT_DATA(3),     0x00000000 },
49 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
50 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
51 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
52 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
53 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00210222 },
54 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00002200 },
55 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00020000 },
56 };
57 
58 static const struct reg_entry rgb_disable[] = {
59 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00000000 },
60 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00000000 },
61 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00000000 },
62 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
63 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
64 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
65 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
66 	{ DC_COM_PIN_OUTPUT_DATA(3),     0xaaaaaaaa },
67 	{ DC_COM_PIN_OUTPUT_DATA(2),     0xaaaaaaaa },
68 	{ DC_COM_PIN_OUTPUT_DATA(1),     0xaaaaaaaa },
69 	{ DC_COM_PIN_OUTPUT_DATA(0),     0xaaaaaaaa },
70 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
71 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
72 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x00000000 },
73 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
74 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x55555555 },
75 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x55555555 },
76 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x55150005 },
77 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x55555555 },
78 };
79 
80 static void tegra_dc_write_regs(struct tegra_dc *dc,
81 				const struct reg_entry *table,
82 				unsigned int num)
83 {
84 	unsigned int i;
85 
86 	for (i = 0; i < num; i++)
87 		tegra_dc_writel(dc, table[i].value, table[i].offset);
88 }
89 
90 static const struct drm_connector_funcs tegra_rgb_connector_funcs = {
91 	.dpms = drm_atomic_helper_connector_dpms,
92 	.reset = drm_atomic_helper_connector_reset,
93 	.detect = tegra_output_connector_detect,
94 	.fill_modes = drm_helper_probe_single_connector_modes,
95 	.destroy = tegra_output_connector_destroy,
96 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
97 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
98 };
99 
100 static enum drm_mode_status
101 tegra_rgb_connector_mode_valid(struct drm_connector *connector,
102 			       struct drm_display_mode *mode)
103 {
104 	/*
105 	 * FIXME: For now, always assume that the mode is okay. There are
106 	 * unresolved issues with clk_round_rate(), which doesn't always
107 	 * reliably report whether a frequency can be set or not.
108 	 */
109 	return MODE_OK;
110 }
111 
112 static const struct drm_connector_helper_funcs tegra_rgb_connector_helper_funcs = {
113 	.get_modes = tegra_output_connector_get_modes,
114 	.mode_valid = tegra_rgb_connector_mode_valid,
115 	.best_encoder = tegra_output_connector_best_encoder,
116 };
117 
118 static const struct drm_encoder_funcs tegra_rgb_encoder_funcs = {
119 	.destroy = tegra_output_encoder_destroy,
120 };
121 
122 static void tegra_rgb_encoder_disable(struct drm_encoder *encoder)
123 {
124 	struct tegra_output *output = encoder_to_output(encoder);
125 	struct tegra_rgb *rgb = to_rgb(output);
126 
127 	if (output->panel)
128 		drm_panel_disable(output->panel);
129 
130 	tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
131 	tegra_dc_commit(rgb->dc);
132 
133 	if (output->panel)
134 		drm_panel_unprepare(output->panel);
135 }
136 
137 static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
138 {
139 	struct tegra_output *output = encoder_to_output(encoder);
140 	struct tegra_rgb *rgb = to_rgb(output);
141 	u32 value;
142 
143 	if (output->panel)
144 		drm_panel_prepare(output->panel);
145 
146 	tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
147 
148 	value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
149 	tegra_dc_writel(rgb->dc, value, DC_DISP_DATA_ENABLE_OPTIONS);
150 
151 	/* XXX: parameterize? */
152 	value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(1));
153 	value &= ~LVS_OUTPUT_POLARITY_LOW;
154 	value &= ~LHS_OUTPUT_POLARITY_LOW;
155 	tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(1));
156 
157 	/* XXX: parameterize? */
158 	value = DISP_DATA_FORMAT_DF1P1C | DISP_ALIGNMENT_MSB |
159 		DISP_ORDER_RED_BLUE;
160 	tegra_dc_writel(rgb->dc, value, DC_DISP_DISP_INTERFACE_CONTROL);
161 
162 	/* XXX: parameterize? */
163 	value = SC0_H_QUALIFIER_NONE | SC1_H_QUALIFIER_NONE;
164 	tegra_dc_writel(rgb->dc, value, DC_DISP_SHIFT_CLOCK_OPTIONS);
165 
166 	tegra_dc_commit(rgb->dc);
167 
168 	if (output->panel)
169 		drm_panel_enable(output->panel);
170 }
171 
172 static int
173 tegra_rgb_encoder_atomic_check(struct drm_encoder *encoder,
174 			       struct drm_crtc_state *crtc_state,
175 			       struct drm_connector_state *conn_state)
176 {
177 	struct tegra_output *output = encoder_to_output(encoder);
178 	struct tegra_dc *dc = to_tegra_dc(conn_state->crtc);
179 	unsigned long pclk = crtc_state->mode.clock * 1000;
180 	struct tegra_rgb *rgb = to_rgb(output);
181 	unsigned int div;
182 	int err;
183 
184 	/*
185 	 * We may not want to change the frequency of the parent clock, since
186 	 * it may be a parent for other peripherals. This is due to the fact
187 	 * that on Tegra20 there's only a single clock dedicated to display
188 	 * (pll_d_out0), whereas later generations have a second one that can
189 	 * be used to independently drive a second output (pll_d2_out0).
190 	 *
191 	 * As a way to support multiple outputs on Tegra20 as well, pll_p is
192 	 * typically used as the parent clock for the display controllers.
193 	 * But this comes at a cost: pll_p is the parent of several other
194 	 * peripherals, so its frequency shouldn't change out of the blue.
195 	 *
196 	 * The best we can do at this point is to use the shift clock divider
197 	 * and hope that the desired frequency can be matched (or at least
198 	 * matched sufficiently close that the panel will still work).
199 	 */
200 	div = ((clk_get_rate(rgb->clk) * 2) / pclk) - 2;
201 	pclk = 0;
202 
203 	err = tegra_dc_state_setup_clock(dc, crtc_state, rgb->clk_parent,
204 					 pclk, div);
205 	if (err < 0) {
206 		dev_err(output->dev, "failed to setup CRTC state: %d\n", err);
207 		return err;
208 	}
209 
210 	return err;
211 }
212 
213 static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = {
214 	.disable = tegra_rgb_encoder_disable,
215 	.enable = tegra_rgb_encoder_enable,
216 	.atomic_check = tegra_rgb_encoder_atomic_check,
217 };
218 
219 int tegra_dc_rgb_probe(struct tegra_dc *dc)
220 {
221 	struct device_node *np;
222 	struct tegra_rgb *rgb;
223 	int err;
224 
225 	np = of_get_child_by_name(dc->dev->of_node, "rgb");
226 	if (!np || !of_device_is_available(np))
227 		return -ENODEV;
228 
229 	rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
230 	if (!rgb)
231 		return -ENOMEM;
232 
233 	rgb->output.dev = dc->dev;
234 	rgb->output.of_node = np;
235 	rgb->dc = dc;
236 
237 	err = tegra_output_probe(&rgb->output);
238 	if (err < 0)
239 		return err;
240 
241 	rgb->clk = devm_clk_get(dc->dev, NULL);
242 	if (IS_ERR(rgb->clk)) {
243 		dev_err(dc->dev, "failed to get clock\n");
244 		return PTR_ERR(rgb->clk);
245 	}
246 
247 	rgb->clk_parent = devm_clk_get(dc->dev, "parent");
248 	if (IS_ERR(rgb->clk_parent)) {
249 		dev_err(dc->dev, "failed to get parent clock\n");
250 		return PTR_ERR(rgb->clk_parent);
251 	}
252 
253 	err = clk_set_parent(rgb->clk, rgb->clk_parent);
254 	if (err < 0) {
255 		dev_err(dc->dev, "failed to set parent clock: %d\n", err);
256 		return err;
257 	}
258 
259 	dc->rgb = &rgb->output;
260 
261 	return 0;
262 }
263 
264 int tegra_dc_rgb_remove(struct tegra_dc *dc)
265 {
266 	if (!dc->rgb)
267 		return 0;
268 
269 	tegra_output_remove(dc->rgb);
270 	dc->rgb = NULL;
271 
272 	return 0;
273 }
274 
275 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
276 {
277 	struct tegra_output *output = dc->rgb;
278 	int err;
279 
280 	if (!dc->rgb)
281 		return -ENODEV;
282 
283 	drm_connector_init(drm, &output->connector, &tegra_rgb_connector_funcs,
284 			   DRM_MODE_CONNECTOR_LVDS);
285 	drm_connector_helper_add(&output->connector,
286 				 &tegra_rgb_connector_helper_funcs);
287 	output->connector.dpms = DRM_MODE_DPMS_OFF;
288 
289 	drm_encoder_init(drm, &output->encoder, &tegra_rgb_encoder_funcs,
290 			 DRM_MODE_ENCODER_LVDS);
291 	drm_encoder_helper_add(&output->encoder,
292 			       &tegra_rgb_encoder_helper_funcs);
293 
294 	drm_mode_connector_attach_encoder(&output->connector,
295 					  &output->encoder);
296 	drm_connector_register(&output->connector);
297 
298 	err = tegra_output_init(drm, output);
299 	if (err < 0) {
300 		dev_err(output->dev, "failed to initialize output: %d\n", err);
301 		return err;
302 	}
303 
304 	/*
305 	 * Other outputs can be attached to either display controller. The RGB
306 	 * outputs are an exception and work only with their parent display
307 	 * controller.
308 	 */
309 	output->encoder.possible_crtcs = drm_crtc_mask(&dc->base);
310 
311 	return 0;
312 }
313 
314 int tegra_dc_rgb_exit(struct tegra_dc *dc)
315 {
316 	if (dc->rgb)
317 		tegra_output_exit(dc->rgb);
318 
319 	return 0;
320 }
321