xref: /linux/drivers/gpu/drm/tegra/rgb.c (revision d198b34f3855eee2571dda03eea75a09c7c31480)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2012 Avionic Design GmbH
4  * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
5  */
6 
7 #include <linux/clk.h>
8 
9 #include <drm/drm_atomic_helper.h>
10 #include <drm/drm_panel.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 
19 	struct clk *clk_parent;
20 	struct clk *clk;
21 };
22 
23 static inline struct tegra_rgb *to_rgb(struct tegra_output *output)
24 {
25 	return container_of(output, struct tegra_rgb, output);
26 }
27 
28 struct reg_entry {
29 	unsigned long offset;
30 	unsigned long value;
31 };
32 
33 static const struct reg_entry rgb_enable[] = {
34 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x00000000 },
35 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x00000000 },
36 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x00000000 },
37 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x00000000 },
38 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
39 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x01000000 },
40 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
41 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
42 	{ DC_COM_PIN_OUTPUT_DATA(0),     0x00000000 },
43 	{ DC_COM_PIN_OUTPUT_DATA(1),     0x00000000 },
44 	{ DC_COM_PIN_OUTPUT_DATA(2),     0x00000000 },
45 	{ DC_COM_PIN_OUTPUT_DATA(3),     0x00000000 },
46 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
47 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
48 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
49 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
50 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00210222 },
51 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00002200 },
52 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00020000 },
53 };
54 
55 static const struct reg_entry rgb_disable[] = {
56 	{ DC_COM_PIN_OUTPUT_SELECT(6),   0x00000000 },
57 	{ DC_COM_PIN_OUTPUT_SELECT(5),   0x00000000 },
58 	{ DC_COM_PIN_OUTPUT_SELECT(4),   0x00000000 },
59 	{ DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
60 	{ DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
61 	{ DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
62 	{ DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
63 	{ DC_COM_PIN_OUTPUT_DATA(3),     0xaaaaaaaa },
64 	{ DC_COM_PIN_OUTPUT_DATA(2),     0xaaaaaaaa },
65 	{ DC_COM_PIN_OUTPUT_DATA(1),     0xaaaaaaaa },
66 	{ DC_COM_PIN_OUTPUT_DATA(0),     0xaaaaaaaa },
67 	{ DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
68 	{ DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
69 	{ DC_COM_PIN_OUTPUT_POLARITY(1), 0x00000000 },
70 	{ DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
71 	{ DC_COM_PIN_OUTPUT_ENABLE(3),   0x55555555 },
72 	{ DC_COM_PIN_OUTPUT_ENABLE(2),   0x55555555 },
73 	{ DC_COM_PIN_OUTPUT_ENABLE(1),   0x55150005 },
74 	{ DC_COM_PIN_OUTPUT_ENABLE(0),   0x55555555 },
75 };
76 
77 static void tegra_dc_write_regs(struct tegra_dc *dc,
78 				const struct reg_entry *table,
79 				unsigned int num)
80 {
81 	unsigned int i;
82 
83 	for (i = 0; i < num; i++)
84 		tegra_dc_writel(dc, table[i].value, table[i].offset);
85 }
86 
87 static const struct drm_connector_funcs tegra_rgb_connector_funcs = {
88 	.reset = drm_atomic_helper_connector_reset,
89 	.detect = tegra_output_connector_detect,
90 	.fill_modes = drm_helper_probe_single_connector_modes,
91 	.destroy = tegra_output_connector_destroy,
92 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
93 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
94 };
95 
96 static enum drm_mode_status
97 tegra_rgb_connector_mode_valid(struct drm_connector *connector,
98 			       struct drm_display_mode *mode)
99 {
100 	/*
101 	 * FIXME: For now, always assume that the mode is okay. There are
102 	 * unresolved issues with clk_round_rate(), which doesn't always
103 	 * reliably report whether a frequency can be set or not.
104 	 */
105 	return MODE_OK;
106 }
107 
108 static const struct drm_connector_helper_funcs tegra_rgb_connector_helper_funcs = {
109 	.get_modes = tegra_output_connector_get_modes,
110 	.mode_valid = tegra_rgb_connector_mode_valid,
111 };
112 
113 static const struct drm_encoder_funcs tegra_rgb_encoder_funcs = {
114 	.destroy = tegra_output_encoder_destroy,
115 };
116 
117 static void tegra_rgb_encoder_disable(struct drm_encoder *encoder)
118 {
119 	struct tegra_output *output = encoder_to_output(encoder);
120 	struct tegra_rgb *rgb = to_rgb(output);
121 
122 	if (output->panel)
123 		drm_panel_disable(output->panel);
124 
125 	tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
126 	tegra_dc_commit(rgb->dc);
127 
128 	if (output->panel)
129 		drm_panel_unprepare(output->panel);
130 }
131 
132 static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
133 {
134 	struct tegra_output *output = encoder_to_output(encoder);
135 	struct tegra_rgb *rgb = to_rgb(output);
136 	u32 value;
137 
138 	if (output->panel)
139 		drm_panel_prepare(output->panel);
140 
141 	tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
142 
143 	value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
144 	tegra_dc_writel(rgb->dc, value, DC_DISP_DATA_ENABLE_OPTIONS);
145 
146 	/* XXX: parameterize? */
147 	value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(1));
148 	value &= ~LVS_OUTPUT_POLARITY_LOW;
149 	value &= ~LHS_OUTPUT_POLARITY_LOW;
150 	tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(1));
151 
152 	/* XXX: parameterize? */
153 	value = DISP_DATA_FORMAT_DF1P1C | DISP_ALIGNMENT_MSB |
154 		DISP_ORDER_RED_BLUE;
155 	tegra_dc_writel(rgb->dc, value, DC_DISP_DISP_INTERFACE_CONTROL);
156 
157 	/* XXX: parameterize? */
158 	value = SC0_H_QUALIFIER_NONE | SC1_H_QUALIFIER_NONE;
159 	tegra_dc_writel(rgb->dc, value, DC_DISP_SHIFT_CLOCK_OPTIONS);
160 
161 	tegra_dc_commit(rgb->dc);
162 
163 	if (output->panel)
164 		drm_panel_enable(output->panel);
165 }
166 
167 static int
168 tegra_rgb_encoder_atomic_check(struct drm_encoder *encoder,
169 			       struct drm_crtc_state *crtc_state,
170 			       struct drm_connector_state *conn_state)
171 {
172 	struct tegra_output *output = encoder_to_output(encoder);
173 	struct tegra_dc *dc = to_tegra_dc(conn_state->crtc);
174 	unsigned long pclk = crtc_state->mode.clock * 1000;
175 	struct tegra_rgb *rgb = to_rgb(output);
176 	unsigned int div;
177 	int err;
178 
179 	/*
180 	 * We may not want to change the frequency of the parent clock, since
181 	 * it may be a parent for other peripherals. This is due to the fact
182 	 * that on Tegra20 there's only a single clock dedicated to display
183 	 * (pll_d_out0), whereas later generations have a second one that can
184 	 * be used to independently drive a second output (pll_d2_out0).
185 	 *
186 	 * As a way to support multiple outputs on Tegra20 as well, pll_p is
187 	 * typically used as the parent clock for the display controllers.
188 	 * But this comes at a cost: pll_p is the parent of several other
189 	 * peripherals, so its frequency shouldn't change out of the blue.
190 	 *
191 	 * The best we can do at this point is to use the shift clock divider
192 	 * and hope that the desired frequency can be matched (or at least
193 	 * matched sufficiently close that the panel will still work).
194 	 */
195 	div = ((clk_get_rate(rgb->clk) * 2) / pclk) - 2;
196 	pclk = 0;
197 
198 	err = tegra_dc_state_setup_clock(dc, crtc_state, rgb->clk_parent,
199 					 pclk, div);
200 	if (err < 0) {
201 		dev_err(output->dev, "failed to setup CRTC state: %d\n", err);
202 		return err;
203 	}
204 
205 	return err;
206 }
207 
208 static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = {
209 	.disable = tegra_rgb_encoder_disable,
210 	.enable = tegra_rgb_encoder_enable,
211 	.atomic_check = tegra_rgb_encoder_atomic_check,
212 };
213 
214 int tegra_dc_rgb_probe(struct tegra_dc *dc)
215 {
216 	struct device_node *np;
217 	struct tegra_rgb *rgb;
218 	int err;
219 
220 	np = of_get_child_by_name(dc->dev->of_node, "rgb");
221 	if (!np || !of_device_is_available(np))
222 		return -ENODEV;
223 
224 	rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
225 	if (!rgb)
226 		return -ENOMEM;
227 
228 	rgb->output.dev = dc->dev;
229 	rgb->output.of_node = np;
230 	rgb->dc = dc;
231 
232 	err = tegra_output_probe(&rgb->output);
233 	if (err < 0)
234 		return err;
235 
236 	rgb->clk = devm_clk_get(dc->dev, NULL);
237 	if (IS_ERR(rgb->clk)) {
238 		dev_err(dc->dev, "failed to get clock\n");
239 		return PTR_ERR(rgb->clk);
240 	}
241 
242 	rgb->clk_parent = devm_clk_get(dc->dev, "parent");
243 	if (IS_ERR(rgb->clk_parent)) {
244 		dev_err(dc->dev, "failed to get parent clock\n");
245 		return PTR_ERR(rgb->clk_parent);
246 	}
247 
248 	err = clk_set_parent(rgb->clk, rgb->clk_parent);
249 	if (err < 0) {
250 		dev_err(dc->dev, "failed to set parent clock: %d\n", err);
251 		return err;
252 	}
253 
254 	dc->rgb = &rgb->output;
255 
256 	return 0;
257 }
258 
259 int tegra_dc_rgb_remove(struct tegra_dc *dc)
260 {
261 	if (!dc->rgb)
262 		return 0;
263 
264 	tegra_output_remove(dc->rgb);
265 	dc->rgb = NULL;
266 
267 	return 0;
268 }
269 
270 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
271 {
272 	struct tegra_output *output = dc->rgb;
273 	int err;
274 
275 	if (!dc->rgb)
276 		return -ENODEV;
277 
278 	drm_connector_init(drm, &output->connector, &tegra_rgb_connector_funcs,
279 			   DRM_MODE_CONNECTOR_LVDS);
280 	drm_connector_helper_add(&output->connector,
281 				 &tegra_rgb_connector_helper_funcs);
282 	output->connector.dpms = DRM_MODE_DPMS_OFF;
283 
284 	drm_encoder_init(drm, &output->encoder, &tegra_rgb_encoder_funcs,
285 			 DRM_MODE_ENCODER_LVDS, NULL);
286 	drm_encoder_helper_add(&output->encoder,
287 			       &tegra_rgb_encoder_helper_funcs);
288 
289 	drm_connector_attach_encoder(&output->connector,
290 					  &output->encoder);
291 	drm_connector_register(&output->connector);
292 
293 	err = tegra_output_init(drm, output);
294 	if (err < 0) {
295 		dev_err(output->dev, "failed to initialize output: %d\n", err);
296 		return err;
297 	}
298 
299 	/*
300 	 * Other outputs can be attached to either display controller. The RGB
301 	 * outputs are an exception and work only with their parent display
302 	 * controller.
303 	 */
304 	output->encoder.possible_crtcs = drm_crtc_mask(&dc->base);
305 
306 	return 0;
307 }
308 
309 int tegra_dc_rgb_exit(struct tegra_dc *dc)
310 {
311 	if (dc->rgb)
312 		tegra_output_exit(dc->rgb);
313 
314 	return 0;
315 }
316