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 #include <linux/of.h>
9
10 #include <drm/drm_atomic_helper.h>
11 #include <drm/drm_bridge_connector.h>
12 #include <drm/drm_simple_kms_helper.h>
13
14 #include "drm.h"
15 #include "dc.h"
16
17 struct tegra_rgb {
18 struct tegra_output output;
19 struct tegra_dc *dc;
20
21 struct clk *pll_d_out0;
22 struct clk *pll_d2_out0;
23 struct clk *clk_parent;
24 struct clk *clk;
25 };
26
to_rgb(struct tegra_output * output)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
tegra_dc_write_regs(struct tegra_dc * dc,const struct reg_entry * table,unsigned int num)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
tegra_rgb_encoder_disable(struct drm_encoder * encoder)91 static void tegra_rgb_encoder_disable(struct drm_encoder *encoder)
92 {
93 struct tegra_output *output = encoder_to_output(encoder);
94 struct tegra_rgb *rgb = to_rgb(output);
95
96 tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
97 tegra_dc_commit(rgb->dc);
98 }
99
tegra_rgb_encoder_enable(struct drm_encoder * encoder)100 static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
101 {
102 struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
103 struct tegra_output *output = encoder_to_output(encoder);
104 struct tegra_rgb *rgb = to_rgb(output);
105 u32 value;
106
107 tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
108
109 value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
110 tegra_dc_writel(rgb->dc, value, DC_DISP_DATA_ENABLE_OPTIONS);
111
112 /* configure H- and V-sync signal polarities */
113 value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(1));
114
115 if (mode->flags & DRM_MODE_FLAG_NHSYNC)
116 value |= LHS_OUTPUT_POLARITY_LOW;
117 else
118 value &= ~LHS_OUTPUT_POLARITY_LOW;
119
120 if (mode->flags & DRM_MODE_FLAG_NVSYNC)
121 value |= LVS_OUTPUT_POLARITY_LOW;
122 else
123 value &= ~LVS_OUTPUT_POLARITY_LOW;
124
125 tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(1));
126
127 /* XXX: parameterize? */
128 value = DISP_DATA_FORMAT_DF1P1C | DISP_ALIGNMENT_MSB |
129 DISP_ORDER_RED_BLUE;
130 tegra_dc_writel(rgb->dc, value, DC_DISP_DISP_INTERFACE_CONTROL);
131
132 tegra_dc_commit(rgb->dc);
133 }
134
tegra_rgb_pll_rate_change_allowed(struct tegra_rgb * rgb)135 static bool tegra_rgb_pll_rate_change_allowed(struct tegra_rgb *rgb)
136 {
137 if (!rgb->pll_d2_out0)
138 return false;
139
140 if (!clk_is_match(rgb->clk_parent, rgb->pll_d_out0) &&
141 !clk_is_match(rgb->clk_parent, rgb->pll_d2_out0))
142 return false;
143
144 return true;
145 }
146
147 static int
tegra_rgb_encoder_atomic_check(struct drm_encoder * encoder,struct drm_crtc_state * crtc_state,struct drm_connector_state * conn_state)148 tegra_rgb_encoder_atomic_check(struct drm_encoder *encoder,
149 struct drm_crtc_state *crtc_state,
150 struct drm_connector_state *conn_state)
151 {
152 struct tegra_output *output = encoder_to_output(encoder);
153 struct tegra_dc *dc = to_tegra_dc(conn_state->crtc);
154 unsigned long pclk = crtc_state->mode.clock * 1000;
155 struct tegra_rgb *rgb = to_rgb(output);
156 unsigned int div;
157 int err;
158
159 /*
160 * We may not want to change the frequency of the parent clock, since
161 * it may be a parent for other peripherals. This is due to the fact
162 * that on Tegra20 there's only a single clock dedicated to display
163 * (pll_d_out0), whereas later generations have a second one that can
164 * be used to independently drive a second output (pll_d2_out0).
165 *
166 * As a way to support multiple outputs on Tegra20 as well, pll_p is
167 * typically used as the parent clock for the display controllers.
168 * But this comes at a cost: pll_p is the parent of several other
169 * peripherals, so its frequency shouldn't change out of the blue.
170 *
171 * The best we can do at this point is to use the shift clock divider
172 * and hope that the desired frequency can be matched (or at least
173 * matched sufficiently close that the panel will still work).
174 */
175 if (tegra_rgb_pll_rate_change_allowed(rgb)) {
176 /*
177 * Set display controller clock to x2 of PCLK in order to
178 * produce higher resolution pulse positions.
179 */
180 div = 2;
181 pclk *= 2;
182 } else {
183 div = ((clk_get_rate(rgb->clk) * 2) / pclk) - 2;
184 pclk = 0;
185 }
186
187 err = tegra_dc_state_setup_clock(dc, crtc_state, rgb->clk_parent,
188 pclk, div);
189 if (err < 0) {
190 dev_err(output->dev, "failed to setup CRTC state: %d\n", err);
191 return err;
192 }
193
194 return err;
195 }
196
197 static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = {
198 .disable = tegra_rgb_encoder_disable,
199 .enable = tegra_rgb_encoder_enable,
200 .atomic_check = tegra_rgb_encoder_atomic_check,
201 };
202
tegra_dc_rgb_probe(struct tegra_dc * dc)203 int tegra_dc_rgb_probe(struct tegra_dc *dc)
204 {
205 struct device_node *np;
206 struct tegra_rgb *rgb;
207 int err;
208
209 np = of_get_child_by_name(dc->dev->of_node, "rgb");
210 if (!np || !of_device_is_available(np))
211 return -ENODEV;
212
213 rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
214 if (!rgb)
215 return -ENOMEM;
216
217 rgb->output.dev = dc->dev;
218 rgb->output.of_node = np;
219 rgb->dc = dc;
220
221 err = tegra_output_probe(&rgb->output);
222 if (err < 0)
223 return err;
224
225 rgb->clk = devm_clk_get(dc->dev, NULL);
226 if (IS_ERR(rgb->clk)) {
227 dev_err(dc->dev, "failed to get clock\n");
228 err = PTR_ERR(rgb->clk);
229 goto remove;
230 }
231
232 rgb->clk_parent = devm_clk_get(dc->dev, "parent");
233 if (IS_ERR(rgb->clk_parent)) {
234 dev_err(dc->dev, "failed to get parent clock\n");
235 err = PTR_ERR(rgb->clk_parent);
236 goto remove;
237 }
238
239 err = clk_set_parent(rgb->clk, rgb->clk_parent);
240 if (err < 0) {
241 dev_err(dc->dev, "failed to set parent clock: %d\n", err);
242 goto remove;
243 }
244
245 rgb->pll_d_out0 = clk_get_sys(NULL, "pll_d_out0");
246 if (IS_ERR(rgb->pll_d_out0)) {
247 err = PTR_ERR(rgb->pll_d_out0);
248 dev_err(dc->dev, "failed to get pll_d_out0: %d\n", err);
249 goto remove;
250 }
251
252 if (dc->soc->has_pll_d2_out0) {
253 rgb->pll_d2_out0 = clk_get_sys(NULL, "pll_d2_out0");
254 if (IS_ERR(rgb->pll_d2_out0)) {
255 err = PTR_ERR(rgb->pll_d2_out0);
256 dev_err(dc->dev, "failed to get pll_d2_out0: %d\n", err);
257 goto put_pll;
258 }
259 }
260
261 dc->rgb = &rgb->output;
262
263 return 0;
264
265 put_pll:
266 clk_put(rgb->pll_d_out0);
267 remove:
268 tegra_output_remove(&rgb->output);
269 return err;
270 }
271
tegra_dc_rgb_remove(struct tegra_dc * dc)272 void tegra_dc_rgb_remove(struct tegra_dc *dc)
273 {
274 struct tegra_rgb *rgb;
275
276 if (!dc->rgb)
277 return;
278
279 rgb = to_rgb(dc->rgb);
280 clk_put(rgb->pll_d2_out0);
281 clk_put(rgb->pll_d_out0);
282
283 tegra_output_remove(dc->rgb);
284 dc->rgb = NULL;
285 }
286
tegra_dc_rgb_init(struct drm_device * drm,struct tegra_dc * dc)287 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
288 {
289 struct tegra_output *output = dc->rgb;
290 struct drm_connector *connector;
291 int err;
292
293 if (!dc->rgb)
294 return -ENODEV;
295
296 drm_simple_encoder_init(drm, &output->encoder, DRM_MODE_ENCODER_LVDS);
297 drm_encoder_helper_add(&output->encoder,
298 &tegra_rgb_encoder_helper_funcs);
299
300 /*
301 * Wrap directly-connected panel into DRM bridge in order to let
302 * DRM core to handle panel for us.
303 */
304 if (output->panel) {
305 output->bridge = devm_drm_panel_bridge_add(output->dev,
306 output->panel);
307 if (IS_ERR(output->bridge)) {
308 dev_err(output->dev,
309 "failed to wrap panel into bridge: %pe\n",
310 output->bridge);
311 return PTR_ERR(output->bridge);
312 }
313
314 output->panel = NULL;
315 }
316
317 /*
318 * Tegra devices that have LVDS panel utilize LVDS encoder bridge
319 * for converting up to 28 LCD LVTTL lanes into 5/4 LVDS lanes that
320 * go to display panel's receiver.
321 *
322 * Encoder usually have a power-down control which needs to be enabled
323 * in order to transmit data to the panel. Historically devices that
324 * use an older device-tree version didn't model the bridge, assuming
325 * that encoder is turned ON by default, while today's DRM allows us
326 * to model LVDS encoder properly.
327 *
328 * Newer device-trees utilize LVDS encoder bridge, which provides
329 * us with a connector and handles the display panel.
330 *
331 * For older device-trees we wrapped panel into the panel-bridge.
332 */
333 if (output->bridge) {
334 err = drm_bridge_attach(&output->encoder, output->bridge,
335 NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
336 if (err)
337 return err;
338
339 connector = drm_bridge_connector_init(drm, &output->encoder);
340 if (IS_ERR(connector)) {
341 dev_err(output->dev,
342 "failed to initialize bridge connector: %pe\n",
343 connector);
344 return PTR_ERR(connector);
345 }
346
347 drm_connector_attach_encoder(connector, &output->encoder);
348 }
349
350 err = tegra_output_init(drm, output);
351 if (err < 0) {
352 dev_err(output->dev, "failed to initialize output: %d\n", err);
353 return err;
354 }
355
356 /*
357 * Other outputs can be attached to either display controller. The RGB
358 * outputs are an exception and work only with their parent display
359 * controller.
360 */
361 output->encoder.possible_crtcs = drm_crtc_mask(&dc->base);
362
363 return 0;
364 }
365
tegra_dc_rgb_exit(struct tegra_dc * dc)366 int tegra_dc_rgb_exit(struct tegra_dc *dc)
367 {
368 if (dc->rgb)
369 tegra_output_exit(dc->rgb);
370
371 return 0;
372 }
373