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