1 // SPDX-License-Identifier: GPL-2.0+
2 
3 /*
4  * Copyright 2020 NXP
5  */
6 
7 #include <linux/firmware/imx/svc/misc.h>
8 #include <linux/mfd/syscon.h>
9 #include <linux/module.h>
10 #include <linux/of.h>
11 #include <linux/of_device.h>
12 #include <linux/of_graph.h>
13 #include <linux/platform_device.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/regmap.h>
16 
17 #include <drm/drm_atomic_state_helper.h>
18 #include <drm/drm_bridge.h>
19 #include <drm/drm_of.h>
20 #include <drm/drm_print.h>
21 
22 #include <dt-bindings/firmware/imx/rsrc.h>
23 
24 #define PXL2DPI_CTRL	0x40
25 #define  CFG1_16BIT	0x0
26 #define  CFG2_16BIT	0x1
27 #define  CFG3_16BIT	0x2
28 #define  CFG1_18BIT	0x3
29 #define  CFG2_18BIT	0x4
30 #define  CFG_24BIT	0x5
31 
32 #define DRIVER_NAME	"imx8qxp-pxl2dpi"
33 
34 struct imx8qxp_pxl2dpi {
35 	struct regmap *regmap;
36 	struct drm_bridge bridge;
37 	struct drm_bridge *next_bridge;
38 	struct drm_bridge *companion;
39 	struct device *dev;
40 	struct imx_sc_ipc *ipc_handle;
41 	u32 sc_resource;
42 	u32 in_bus_format;
43 	u32 out_bus_format;
44 	u32 pl_sel;
45 };
46 
47 #define bridge_to_p2d(b)	container_of(b, struct imx8qxp_pxl2dpi, bridge)
48 
49 static int imx8qxp_pxl2dpi_bridge_attach(struct drm_bridge *bridge,
50 					 enum drm_bridge_attach_flags flags)
51 {
52 	struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;
53 
54 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
55 		DRM_DEV_ERROR(p2d->dev,
56 			      "do not support creating a drm_connector\n");
57 		return -EINVAL;
58 	}
59 
60 	if (!bridge->encoder) {
61 		DRM_DEV_ERROR(p2d->dev, "missing encoder\n");
62 		return -ENODEV;
63 	}
64 
65 	return drm_bridge_attach(bridge->encoder,
66 				 p2d->next_bridge, bridge,
67 				 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
68 }
69 
70 static int
71 imx8qxp_pxl2dpi_bridge_atomic_check(struct drm_bridge *bridge,
72 				    struct drm_bridge_state *bridge_state,
73 				    struct drm_crtc_state *crtc_state,
74 				    struct drm_connector_state *conn_state)
75 {
76 	struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;
77 
78 	p2d->in_bus_format = bridge_state->input_bus_cfg.format;
79 	p2d->out_bus_format = bridge_state->output_bus_cfg.format;
80 
81 	return 0;
82 }
83 
84 static void
85 imx8qxp_pxl2dpi_bridge_mode_set(struct drm_bridge *bridge,
86 				const struct drm_display_mode *mode,
87 				const struct drm_display_mode *adjusted_mode)
88 {
89 	struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;
90 	struct imx8qxp_pxl2dpi *companion_p2d;
91 	int ret;
92 
93 	ret = pm_runtime_get_sync(p2d->dev);
94 	if (ret < 0)
95 		DRM_DEV_ERROR(p2d->dev,
96 			      "failed to get runtime PM sync: %d\n", ret);
97 
98 	ret = imx_sc_misc_set_control(p2d->ipc_handle, p2d->sc_resource,
99 				      IMX_SC_C_PXL_LINK_SEL, p2d->pl_sel);
100 	if (ret)
101 		DRM_DEV_ERROR(p2d->dev,
102 			      "failed to set pixel link selection(%u): %d\n",
103 							p2d->pl_sel, ret);
104 
105 	switch (p2d->out_bus_format) {
106 	case MEDIA_BUS_FMT_RGB888_1X24:
107 		regmap_write(p2d->regmap, PXL2DPI_CTRL, CFG_24BIT);
108 		break;
109 	case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
110 		regmap_write(p2d->regmap, PXL2DPI_CTRL, CFG2_18BIT);
111 		break;
112 	default:
113 		DRM_DEV_ERROR(p2d->dev,
114 			      "unsupported output bus format 0x%08x\n",
115 							p2d->out_bus_format);
116 	}
117 
118 	if (p2d->companion) {
119 		companion_p2d = bridge_to_p2d(p2d->companion);
120 
121 		companion_p2d->in_bus_format = p2d->in_bus_format;
122 		companion_p2d->out_bus_format = p2d->out_bus_format;
123 
124 		p2d->companion->funcs->mode_set(p2d->companion, mode,
125 							adjusted_mode);
126 	}
127 }
128 
129 static void
130 imx8qxp_pxl2dpi_bridge_atomic_disable(struct drm_bridge *bridge,
131 				      struct drm_bridge_state *old_bridge_state)
132 {
133 	struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;
134 	int ret;
135 
136 	ret = pm_runtime_put(p2d->dev);
137 	if (ret < 0)
138 		DRM_DEV_ERROR(p2d->dev, "failed to put runtime PM: %d\n", ret);
139 
140 	if (p2d->companion)
141 		p2d->companion->funcs->atomic_disable(p2d->companion,
142 							old_bridge_state);
143 }
144 
145 static const u32 imx8qxp_pxl2dpi_bus_output_fmts[] = {
146 	MEDIA_BUS_FMT_RGB888_1X24,
147 	MEDIA_BUS_FMT_RGB666_1X24_CPADHI,
148 };
149 
150 static bool imx8qxp_pxl2dpi_bus_output_fmt_supported(u32 fmt)
151 {
152 	int i;
153 
154 	for (i = 0; i < ARRAY_SIZE(imx8qxp_pxl2dpi_bus_output_fmts); i++) {
155 		if (imx8qxp_pxl2dpi_bus_output_fmts[i] == fmt)
156 			return true;
157 	}
158 
159 	return false;
160 }
161 
162 static u32 *
163 imx8qxp_pxl2dpi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
164 						 struct drm_bridge_state *bridge_state,
165 						 struct drm_crtc_state *crtc_state,
166 						 struct drm_connector_state *conn_state,
167 						 u32 output_fmt,
168 						 unsigned int *num_input_fmts)
169 {
170 	u32 *input_fmts;
171 
172 	if (!imx8qxp_pxl2dpi_bus_output_fmt_supported(output_fmt))
173 		return NULL;
174 
175 	*num_input_fmts = 1;
176 
177 	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
178 	if (!input_fmts)
179 		return NULL;
180 
181 	switch (output_fmt) {
182 	case MEDIA_BUS_FMT_RGB888_1X24:
183 		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X36_CPADLO;
184 		break;
185 	case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
186 		input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X36_CPADLO;
187 		break;
188 	default:
189 		kfree(input_fmts);
190 		input_fmts = NULL;
191 		break;
192 	}
193 
194 	return input_fmts;
195 }
196 
197 static u32 *
198 imx8qxp_pxl2dpi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
199 						  struct drm_bridge_state *bridge_state,
200 						  struct drm_crtc_state *crtc_state,
201 						  struct drm_connector_state *conn_state,
202 						  unsigned int *num_output_fmts)
203 {
204 	*num_output_fmts = ARRAY_SIZE(imx8qxp_pxl2dpi_bus_output_fmts);
205 	return kmemdup(imx8qxp_pxl2dpi_bus_output_fmts,
206 			sizeof(imx8qxp_pxl2dpi_bus_output_fmts), GFP_KERNEL);
207 }
208 
209 static const struct drm_bridge_funcs imx8qxp_pxl2dpi_bridge_funcs = {
210 	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
211 	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
212 	.atomic_reset		= drm_atomic_helper_bridge_reset,
213 	.attach			= imx8qxp_pxl2dpi_bridge_attach,
214 	.atomic_check		= imx8qxp_pxl2dpi_bridge_atomic_check,
215 	.mode_set		= imx8qxp_pxl2dpi_bridge_mode_set,
216 	.atomic_disable		= imx8qxp_pxl2dpi_bridge_atomic_disable,
217 	.atomic_get_input_bus_fmts =
218 			imx8qxp_pxl2dpi_bridge_atomic_get_input_bus_fmts,
219 	.atomic_get_output_bus_fmts =
220 			imx8qxp_pxl2dpi_bridge_atomic_get_output_bus_fmts,
221 };
222 
223 static struct device_node *
224 imx8qxp_pxl2dpi_get_available_ep_from_port(struct imx8qxp_pxl2dpi *p2d,
225 					   u32 port_id)
226 {
227 	struct device_node *port, *ep;
228 	int ep_cnt;
229 
230 	port = of_graph_get_port_by_id(p2d->dev->of_node, port_id);
231 	if (!port) {
232 		DRM_DEV_ERROR(p2d->dev, "failed to get port@%u\n", port_id);
233 		return ERR_PTR(-ENODEV);
234 	}
235 
236 	ep_cnt = of_get_available_child_count(port);
237 	if (ep_cnt == 0) {
238 		DRM_DEV_ERROR(p2d->dev, "no available endpoints of port@%u\n",
239 			      port_id);
240 		ep = ERR_PTR(-ENODEV);
241 		goto out;
242 	} else if (ep_cnt > 1) {
243 		DRM_DEV_ERROR(p2d->dev,
244 			      "invalid available endpoints of port@%u\n",
245 			      port_id);
246 		ep = ERR_PTR(-EINVAL);
247 		goto out;
248 	}
249 
250 	ep = of_get_next_available_child(port, NULL);
251 	if (!ep) {
252 		DRM_DEV_ERROR(p2d->dev,
253 			      "failed to get available endpoint of port@%u\n",
254 			      port_id);
255 		ep = ERR_PTR(-ENODEV);
256 		goto out;
257 	}
258 out:
259 	of_node_put(port);
260 	return ep;
261 }
262 
263 static struct drm_bridge *
264 imx8qxp_pxl2dpi_find_next_bridge(struct imx8qxp_pxl2dpi *p2d)
265 {
266 	struct device_node *ep, *remote;
267 	struct drm_bridge *next_bridge;
268 	int ret;
269 
270 	ep = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 1);
271 	if (IS_ERR(ep)) {
272 		ret = PTR_ERR(ep);
273 		return ERR_PTR(ret);
274 	}
275 
276 	remote = of_graph_get_remote_port_parent(ep);
277 	if (!remote || !of_device_is_available(remote)) {
278 		DRM_DEV_ERROR(p2d->dev, "no available remote\n");
279 		next_bridge = ERR_PTR(-ENODEV);
280 		goto out;
281 	} else if (!of_device_is_available(remote->parent)) {
282 		DRM_DEV_ERROR(p2d->dev, "remote parent is not available\n");
283 		next_bridge = ERR_PTR(-ENODEV);
284 		goto out;
285 	}
286 
287 	next_bridge = of_drm_find_bridge(remote);
288 	if (!next_bridge) {
289 		next_bridge = ERR_PTR(-EPROBE_DEFER);
290 		goto out;
291 	}
292 out:
293 	of_node_put(remote);
294 	of_node_put(ep);
295 
296 	return next_bridge;
297 }
298 
299 static int imx8qxp_pxl2dpi_set_pixel_link_sel(struct imx8qxp_pxl2dpi *p2d)
300 {
301 	struct device_node *ep;
302 	struct of_endpoint endpoint;
303 	int ret;
304 
305 	ep = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 0);
306 	if (IS_ERR(ep))
307 		return PTR_ERR(ep);
308 
309 	ret = of_graph_parse_endpoint(ep, &endpoint);
310 	if (ret) {
311 		DRM_DEV_ERROR(p2d->dev,
312 			      "failed to parse endpoint of port@0: %d\n", ret);
313 		goto out;
314 	}
315 
316 	p2d->pl_sel = endpoint.id;
317 out:
318 	of_node_put(ep);
319 
320 	return ret;
321 }
322 
323 static int imx8qxp_pxl2dpi_parse_dt_companion(struct imx8qxp_pxl2dpi *p2d)
324 {
325 	struct imx8qxp_pxl2dpi *companion_p2d;
326 	struct device *dev = p2d->dev;
327 	struct device_node *companion;
328 	struct device_node *port1, *port2;
329 	const struct of_device_id *match;
330 	int dual_link;
331 	int ret = 0;
332 
333 	/* Locate the companion PXL2DPI for dual-link operation, if any. */
334 	companion = of_parse_phandle(dev->of_node, "fsl,companion-pxl2dpi", 0);
335 	if (!companion)
336 		return 0;
337 
338 	if (!of_device_is_available(companion)) {
339 		DRM_DEV_ERROR(dev, "companion PXL2DPI is not available\n");
340 		ret = -ENODEV;
341 		goto out;
342 	}
343 
344 	/*
345 	 * Sanity check: the companion bridge must have the same compatible
346 	 * string.
347 	 */
348 	match = of_match_device(dev->driver->of_match_table, dev);
349 	if (!of_device_is_compatible(companion, match->compatible)) {
350 		DRM_DEV_ERROR(dev, "companion PXL2DPI is incompatible\n");
351 		ret = -ENXIO;
352 		goto out;
353 	}
354 
355 	p2d->companion = of_drm_find_bridge(companion);
356 	if (!p2d->companion) {
357 		ret = -EPROBE_DEFER;
358 		DRM_DEV_DEBUG_DRIVER(p2d->dev,
359 				     "failed to find companion bridge: %d\n",
360 				     ret);
361 		goto out;
362 	}
363 
364 	companion_p2d = bridge_to_p2d(p2d->companion);
365 
366 	/*
367 	 * We need to work out if the sink is expecting us to function in
368 	 * dual-link mode.  We do this by looking at the DT port nodes that
369 	 * the next bridges are connected to.  If they are marked as expecting
370 	 * even pixels and odd pixels than we need to use the companion PXL2DPI.
371 	 */
372 	port1 = of_graph_get_port_by_id(p2d->next_bridge->of_node, 1);
373 	port2 = of_graph_get_port_by_id(companion_p2d->next_bridge->of_node, 1);
374 	dual_link = drm_of_lvds_get_dual_link_pixel_order(port1, port2);
375 	of_node_put(port1);
376 	of_node_put(port2);
377 
378 	if (dual_link < 0) {
379 		ret = dual_link;
380 		DRM_DEV_ERROR(dev, "failed to get dual link pixel order: %d\n",
381 			      ret);
382 		goto out;
383 	}
384 
385 	DRM_DEV_DEBUG_DRIVER(dev,
386 			     "dual-link configuration detected (companion bridge %pOF)\n",
387 			     companion);
388 out:
389 	of_node_put(companion);
390 	return ret;
391 }
392 
393 static int imx8qxp_pxl2dpi_bridge_probe(struct platform_device *pdev)
394 {
395 	struct imx8qxp_pxl2dpi *p2d;
396 	struct device *dev = &pdev->dev;
397 	struct device_node *np = dev->of_node;
398 	int ret;
399 
400 	p2d = devm_kzalloc(dev, sizeof(*p2d), GFP_KERNEL);
401 	if (!p2d)
402 		return -ENOMEM;
403 
404 	p2d->regmap = syscon_node_to_regmap(np->parent);
405 	if (IS_ERR(p2d->regmap)) {
406 		ret = PTR_ERR(p2d->regmap);
407 		if (ret != -EPROBE_DEFER)
408 			DRM_DEV_ERROR(dev, "failed to get regmap: %d\n", ret);
409 		return ret;
410 	}
411 
412 	ret = imx_scu_get_handle(&p2d->ipc_handle);
413 	if (ret) {
414 		if (ret != -EPROBE_DEFER)
415 			DRM_DEV_ERROR(dev, "failed to get SCU ipc handle: %d\n",
416 				      ret);
417 		return ret;
418 	}
419 
420 	p2d->dev = dev;
421 
422 	ret = of_property_read_u32(np, "fsl,sc-resource", &p2d->sc_resource);
423 	if (ret) {
424 		DRM_DEV_ERROR(dev, "failed to get SC resource %d\n", ret);
425 		return ret;
426 	}
427 
428 	p2d->next_bridge = imx8qxp_pxl2dpi_find_next_bridge(p2d);
429 	if (IS_ERR(p2d->next_bridge)) {
430 		ret = PTR_ERR(p2d->next_bridge);
431 		if (ret != -EPROBE_DEFER)
432 			DRM_DEV_ERROR(dev, "failed to find next bridge: %d\n",
433 				      ret);
434 		return ret;
435 	}
436 
437 	ret = imx8qxp_pxl2dpi_set_pixel_link_sel(p2d);
438 	if (ret)
439 		return ret;
440 
441 	ret = imx8qxp_pxl2dpi_parse_dt_companion(p2d);
442 	if (ret)
443 		return ret;
444 
445 	platform_set_drvdata(pdev, p2d);
446 	pm_runtime_enable(dev);
447 
448 	p2d->bridge.driver_private = p2d;
449 	p2d->bridge.funcs = &imx8qxp_pxl2dpi_bridge_funcs;
450 	p2d->bridge.of_node = np;
451 
452 	drm_bridge_add(&p2d->bridge);
453 
454 	return ret;
455 }
456 
457 static int imx8qxp_pxl2dpi_bridge_remove(struct platform_device *pdev)
458 {
459 	struct imx8qxp_pxl2dpi *p2d = platform_get_drvdata(pdev);
460 
461 	drm_bridge_remove(&p2d->bridge);
462 
463 	pm_runtime_disable(&pdev->dev);
464 
465 	return 0;
466 }
467 
468 static const struct of_device_id imx8qxp_pxl2dpi_dt_ids[] = {
469 	{ .compatible = "fsl,imx8qxp-pxl2dpi", },
470 	{ /* sentinel */ }
471 };
472 MODULE_DEVICE_TABLE(of, imx8qxp_pxl2dpi_dt_ids);
473 
474 static struct platform_driver imx8qxp_pxl2dpi_bridge_driver = {
475 	.probe	= imx8qxp_pxl2dpi_bridge_probe,
476 	.remove = imx8qxp_pxl2dpi_bridge_remove,
477 	.driver	= {
478 		.of_match_table = imx8qxp_pxl2dpi_dt_ids,
479 		.name = DRIVER_NAME,
480 	},
481 };
482 module_platform_driver(imx8qxp_pxl2dpi_bridge_driver);
483 
484 MODULE_DESCRIPTION("i.MX8QXP pixel link to DPI bridge driver");
485 MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
486 MODULE_LICENSE("GPL v2");
487 MODULE_ALIAS("platform:" DRIVER_NAME);
488