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/media-bus-format.h>
9 #include <linux/mfd/syscon.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/of_device.h>
13 #include <linux/of_graph.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/regmap.h>
17 
18 #include <drm/drm_atomic_state_helper.h>
19 #include <drm/drm_bridge.h>
20 #include <drm/drm_of.h>
21 #include <drm/drm_print.h>
22 
23 #include <dt-bindings/firmware/imx/rsrc.h>
24 
25 #define PXL2DPI_CTRL	0x40
26 #define  CFG1_16BIT	0x0
27 #define  CFG2_16BIT	0x1
28 #define  CFG3_16BIT	0x2
29 #define  CFG1_18BIT	0x3
30 #define  CFG2_18BIT	0x4
31 #define  CFG_24BIT	0x5
32 
33 #define DRIVER_NAME	"imx8qxp-pxl2dpi"
34 
35 struct imx8qxp_pxl2dpi {
36 	struct regmap *regmap;
37 	struct drm_bridge bridge;
38 	struct drm_bridge *next_bridge;
39 	struct drm_bridge *companion;
40 	struct device *dev;
41 	struct imx_sc_ipc *ipc_handle;
42 	u32 sc_resource;
43 	u32 in_bus_format;
44 	u32 out_bus_format;
45 	u32 pl_sel;
46 };
47 
48 #define bridge_to_p2d(b)	container_of(b, struct imx8qxp_pxl2dpi, bridge)
49 
50 static int imx8qxp_pxl2dpi_bridge_attach(struct drm_bridge *bridge,
51 					 enum drm_bridge_attach_flags flags)
52 {
53 	struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;
54 
55 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
56 		DRM_DEV_ERROR(p2d->dev,
57 			      "do not support creating a drm_connector\n");
58 		return -EINVAL;
59 	}
60 
61 	if (!bridge->encoder) {
62 		DRM_DEV_ERROR(p2d->dev, "missing encoder\n");
63 		return -ENODEV;
64 	}
65 
66 	return drm_bridge_attach(bridge->encoder,
67 				 p2d->next_bridge, bridge,
68 				 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
69 }
70 
71 static int
72 imx8qxp_pxl2dpi_bridge_atomic_check(struct drm_bridge *bridge,
73 				    struct drm_bridge_state *bridge_state,
74 				    struct drm_crtc_state *crtc_state,
75 				    struct drm_connector_state *conn_state)
76 {
77 	struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;
78 
79 	p2d->in_bus_format = bridge_state->input_bus_cfg.format;
80 	p2d->out_bus_format = bridge_state->output_bus_cfg.format;
81 
82 	return 0;
83 }
84 
85 static void
86 imx8qxp_pxl2dpi_bridge_mode_set(struct drm_bridge *bridge,
87 				const struct drm_display_mode *mode,
88 				const struct drm_display_mode *adjusted_mode)
89 {
90 	struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;
91 	struct imx8qxp_pxl2dpi *companion_p2d;
92 	int ret;
93 
94 	ret = pm_runtime_get_sync(p2d->dev);
95 	if (ret < 0)
96 		DRM_DEV_ERROR(p2d->dev,
97 			      "failed to get runtime PM sync: %d\n", ret);
98 
99 	ret = imx_sc_misc_set_control(p2d->ipc_handle, p2d->sc_resource,
100 				      IMX_SC_C_PXL_LINK_SEL, p2d->pl_sel);
101 	if (ret)
102 		DRM_DEV_ERROR(p2d->dev,
103 			      "failed to set pixel link selection(%u): %d\n",
104 							p2d->pl_sel, ret);
105 
106 	switch (p2d->out_bus_format) {
107 	case MEDIA_BUS_FMT_RGB888_1X24:
108 		regmap_write(p2d->regmap, PXL2DPI_CTRL, CFG_24BIT);
109 		break;
110 	case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
111 		regmap_write(p2d->regmap, PXL2DPI_CTRL, CFG2_18BIT);
112 		break;
113 	default:
114 		DRM_DEV_ERROR(p2d->dev,
115 			      "unsupported output bus format 0x%08x\n",
116 							p2d->out_bus_format);
117 	}
118 
119 	if (p2d->companion) {
120 		companion_p2d = bridge_to_p2d(p2d->companion);
121 
122 		companion_p2d->in_bus_format = p2d->in_bus_format;
123 		companion_p2d->out_bus_format = p2d->out_bus_format;
124 
125 		p2d->companion->funcs->mode_set(p2d->companion, mode,
126 							adjusted_mode);
127 	}
128 }
129 
130 static void
131 imx8qxp_pxl2dpi_bridge_atomic_disable(struct drm_bridge *bridge,
132 				      struct drm_bridge_state *old_bridge_state)
133 {
134 	struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;
135 	int ret;
136 
137 	ret = pm_runtime_put(p2d->dev);
138 	if (ret < 0)
139 		DRM_DEV_ERROR(p2d->dev, "failed to put runtime PM: %d\n", ret);
140 
141 	if (p2d->companion)
142 		p2d->companion->funcs->atomic_disable(p2d->companion,
143 							old_bridge_state);
144 }
145 
146 static const u32 imx8qxp_pxl2dpi_bus_output_fmts[] = {
147 	MEDIA_BUS_FMT_RGB888_1X24,
148 	MEDIA_BUS_FMT_RGB666_1X24_CPADHI,
149 };
150 
151 static bool imx8qxp_pxl2dpi_bus_output_fmt_supported(u32 fmt)
152 {
153 	int i;
154 
155 	for (i = 0; i < ARRAY_SIZE(imx8qxp_pxl2dpi_bus_output_fmts); i++) {
156 		if (imx8qxp_pxl2dpi_bus_output_fmts[i] == fmt)
157 			return true;
158 	}
159 
160 	return false;
161 }
162 
163 static u32 *
164 imx8qxp_pxl2dpi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
165 						 struct drm_bridge_state *bridge_state,
166 						 struct drm_crtc_state *crtc_state,
167 						 struct drm_connector_state *conn_state,
168 						 u32 output_fmt,
169 						 unsigned int *num_input_fmts)
170 {
171 	u32 *input_fmts;
172 
173 	if (!imx8qxp_pxl2dpi_bus_output_fmt_supported(output_fmt))
174 		return NULL;
175 
176 	*num_input_fmts = 1;
177 
178 	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
179 	if (!input_fmts)
180 		return NULL;
181 
182 	switch (output_fmt) {
183 	case MEDIA_BUS_FMT_RGB888_1X24:
184 		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X36_CPADLO;
185 		break;
186 	case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
187 		input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X36_CPADLO;
188 		break;
189 	default:
190 		kfree(input_fmts);
191 		input_fmts = NULL;
192 		break;
193 	}
194 
195 	return input_fmts;
196 }
197 
198 static u32 *
199 imx8qxp_pxl2dpi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
200 						  struct drm_bridge_state *bridge_state,
201 						  struct drm_crtc_state *crtc_state,
202 						  struct drm_connector_state *conn_state,
203 						  unsigned int *num_output_fmts)
204 {
205 	*num_output_fmts = ARRAY_SIZE(imx8qxp_pxl2dpi_bus_output_fmts);
206 	return kmemdup(imx8qxp_pxl2dpi_bus_output_fmts,
207 			sizeof(imx8qxp_pxl2dpi_bus_output_fmts), GFP_KERNEL);
208 }
209 
210 static const struct drm_bridge_funcs imx8qxp_pxl2dpi_bridge_funcs = {
211 	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
212 	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
213 	.atomic_reset		= drm_atomic_helper_bridge_reset,
214 	.attach			= imx8qxp_pxl2dpi_bridge_attach,
215 	.atomic_check		= imx8qxp_pxl2dpi_bridge_atomic_check,
216 	.mode_set		= imx8qxp_pxl2dpi_bridge_mode_set,
217 	.atomic_disable		= imx8qxp_pxl2dpi_bridge_atomic_disable,
218 	.atomic_get_input_bus_fmts =
219 			imx8qxp_pxl2dpi_bridge_atomic_get_input_bus_fmts,
220 	.atomic_get_output_bus_fmts =
221 			imx8qxp_pxl2dpi_bridge_atomic_get_output_bus_fmts,
222 };
223 
224 static struct device_node *
225 imx8qxp_pxl2dpi_get_available_ep_from_port(struct imx8qxp_pxl2dpi *p2d,
226 					   u32 port_id)
227 {
228 	struct device_node *port, *ep;
229 	int ep_cnt;
230 
231 	port = of_graph_get_port_by_id(p2d->dev->of_node, port_id);
232 	if (!port) {
233 		DRM_DEV_ERROR(p2d->dev, "failed to get port@%u\n", port_id);
234 		return ERR_PTR(-ENODEV);
235 	}
236 
237 	ep_cnt = of_get_available_child_count(port);
238 	if (ep_cnt == 0) {
239 		DRM_DEV_ERROR(p2d->dev, "no available endpoints of port@%u\n",
240 			      port_id);
241 		ep = ERR_PTR(-ENODEV);
242 		goto out;
243 	} else if (ep_cnt > 1) {
244 		DRM_DEV_ERROR(p2d->dev,
245 			      "invalid available endpoints of port@%u\n",
246 			      port_id);
247 		ep = ERR_PTR(-EINVAL);
248 		goto out;
249 	}
250 
251 	ep = of_get_next_available_child(port, NULL);
252 	if (!ep) {
253 		DRM_DEV_ERROR(p2d->dev,
254 			      "failed to get available endpoint of port@%u\n",
255 			      port_id);
256 		ep = ERR_PTR(-ENODEV);
257 		goto out;
258 	}
259 out:
260 	of_node_put(port);
261 	return ep;
262 }
263 
264 static struct drm_bridge *
265 imx8qxp_pxl2dpi_find_next_bridge(struct imx8qxp_pxl2dpi *p2d)
266 {
267 	struct device_node *ep, *remote;
268 	struct drm_bridge *next_bridge;
269 	int ret;
270 
271 	ep = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 1);
272 	if (IS_ERR(ep)) {
273 		ret = PTR_ERR(ep);
274 		return ERR_PTR(ret);
275 	}
276 
277 	remote = of_graph_get_remote_port_parent(ep);
278 	if (!remote || !of_device_is_available(remote)) {
279 		DRM_DEV_ERROR(p2d->dev, "no available remote\n");
280 		next_bridge = ERR_PTR(-ENODEV);
281 		goto out;
282 	} else if (!of_device_is_available(remote->parent)) {
283 		DRM_DEV_ERROR(p2d->dev, "remote parent is not available\n");
284 		next_bridge = ERR_PTR(-ENODEV);
285 		goto out;
286 	}
287 
288 	next_bridge = of_drm_find_bridge(remote);
289 	if (!next_bridge) {
290 		next_bridge = ERR_PTR(-EPROBE_DEFER);
291 		goto out;
292 	}
293 out:
294 	of_node_put(remote);
295 	of_node_put(ep);
296 
297 	return next_bridge;
298 }
299 
300 static int imx8qxp_pxl2dpi_set_pixel_link_sel(struct imx8qxp_pxl2dpi *p2d)
301 {
302 	struct device_node *ep;
303 	struct of_endpoint endpoint;
304 	int ret;
305 
306 	ep = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 0);
307 	if (IS_ERR(ep))
308 		return PTR_ERR(ep);
309 
310 	ret = of_graph_parse_endpoint(ep, &endpoint);
311 	if (ret) {
312 		DRM_DEV_ERROR(p2d->dev,
313 			      "failed to parse endpoint of port@0: %d\n", ret);
314 		goto out;
315 	}
316 
317 	p2d->pl_sel = endpoint.id;
318 out:
319 	of_node_put(ep);
320 
321 	return ret;
322 }
323 
324 static int imx8qxp_pxl2dpi_parse_dt_companion(struct imx8qxp_pxl2dpi *p2d)
325 {
326 	struct imx8qxp_pxl2dpi *companion_p2d;
327 	struct device *dev = p2d->dev;
328 	struct device_node *companion;
329 	struct device_node *port1, *port2;
330 	const struct of_device_id *match;
331 	int dual_link;
332 	int ret = 0;
333 
334 	/* Locate the companion PXL2DPI for dual-link operation, if any. */
335 	companion = of_parse_phandle(dev->of_node, "fsl,companion-pxl2dpi", 0);
336 	if (!companion)
337 		return 0;
338 
339 	if (!of_device_is_available(companion)) {
340 		DRM_DEV_ERROR(dev, "companion PXL2DPI is not available\n");
341 		ret = -ENODEV;
342 		goto out;
343 	}
344 
345 	/*
346 	 * Sanity check: the companion bridge must have the same compatible
347 	 * string.
348 	 */
349 	match = of_match_device(dev->driver->of_match_table, dev);
350 	if (!of_device_is_compatible(companion, match->compatible)) {
351 		DRM_DEV_ERROR(dev, "companion PXL2DPI is incompatible\n");
352 		ret = -ENXIO;
353 		goto out;
354 	}
355 
356 	p2d->companion = of_drm_find_bridge(companion);
357 	if (!p2d->companion) {
358 		ret = -EPROBE_DEFER;
359 		DRM_DEV_DEBUG_DRIVER(p2d->dev,
360 				     "failed to find companion bridge: %d\n",
361 				     ret);
362 		goto out;
363 	}
364 
365 	companion_p2d = bridge_to_p2d(p2d->companion);
366 
367 	/*
368 	 * We need to work out if the sink is expecting us to function in
369 	 * dual-link mode.  We do this by looking at the DT port nodes that
370 	 * the next bridges are connected to.  If they are marked as expecting
371 	 * even pixels and odd pixels than we need to use the companion PXL2DPI.
372 	 */
373 	port1 = of_graph_get_port_by_id(p2d->next_bridge->of_node, 1);
374 	port2 = of_graph_get_port_by_id(companion_p2d->next_bridge->of_node, 1);
375 	dual_link = drm_of_lvds_get_dual_link_pixel_order(port1, port2);
376 	of_node_put(port1);
377 	of_node_put(port2);
378 
379 	if (dual_link < 0) {
380 		ret = dual_link;
381 		DRM_DEV_ERROR(dev, "failed to get dual link pixel order: %d\n",
382 			      ret);
383 		goto out;
384 	}
385 
386 	DRM_DEV_DEBUG_DRIVER(dev,
387 			     "dual-link configuration detected (companion bridge %pOF)\n",
388 			     companion);
389 out:
390 	of_node_put(companion);
391 	return ret;
392 }
393 
394 static int imx8qxp_pxl2dpi_bridge_probe(struct platform_device *pdev)
395 {
396 	struct imx8qxp_pxl2dpi *p2d;
397 	struct device *dev = &pdev->dev;
398 	struct device_node *np = dev->of_node;
399 	int ret;
400 
401 	p2d = devm_kzalloc(dev, sizeof(*p2d), GFP_KERNEL);
402 	if (!p2d)
403 		return -ENOMEM;
404 
405 	p2d->regmap = syscon_node_to_regmap(np->parent);
406 	if (IS_ERR(p2d->regmap)) {
407 		ret = PTR_ERR(p2d->regmap);
408 		if (ret != -EPROBE_DEFER)
409 			DRM_DEV_ERROR(dev, "failed to get regmap: %d\n", ret);
410 		return ret;
411 	}
412 
413 	ret = imx_scu_get_handle(&p2d->ipc_handle);
414 	if (ret) {
415 		if (ret != -EPROBE_DEFER)
416 			DRM_DEV_ERROR(dev, "failed to get SCU ipc handle: %d\n",
417 				      ret);
418 		return ret;
419 	}
420 
421 	p2d->dev = dev;
422 
423 	ret = of_property_read_u32(np, "fsl,sc-resource", &p2d->sc_resource);
424 	if (ret) {
425 		DRM_DEV_ERROR(dev, "failed to get SC resource %d\n", ret);
426 		return ret;
427 	}
428 
429 	p2d->next_bridge = imx8qxp_pxl2dpi_find_next_bridge(p2d);
430 	if (IS_ERR(p2d->next_bridge)) {
431 		ret = PTR_ERR(p2d->next_bridge);
432 		if (ret != -EPROBE_DEFER)
433 			DRM_DEV_ERROR(dev, "failed to find next bridge: %d\n",
434 				      ret);
435 		return ret;
436 	}
437 
438 	ret = imx8qxp_pxl2dpi_set_pixel_link_sel(p2d);
439 	if (ret)
440 		return ret;
441 
442 	ret = imx8qxp_pxl2dpi_parse_dt_companion(p2d);
443 	if (ret)
444 		return ret;
445 
446 	platform_set_drvdata(pdev, p2d);
447 	pm_runtime_enable(dev);
448 
449 	p2d->bridge.driver_private = p2d;
450 	p2d->bridge.funcs = &imx8qxp_pxl2dpi_bridge_funcs;
451 	p2d->bridge.of_node = np;
452 
453 	drm_bridge_add(&p2d->bridge);
454 
455 	return ret;
456 }
457 
458 static int imx8qxp_pxl2dpi_bridge_remove(struct platform_device *pdev)
459 {
460 	struct imx8qxp_pxl2dpi *p2d = platform_get_drvdata(pdev);
461 
462 	drm_bridge_remove(&p2d->bridge);
463 
464 	pm_runtime_disable(&pdev->dev);
465 
466 	return 0;
467 }
468 
469 static const struct of_device_id imx8qxp_pxl2dpi_dt_ids[] = {
470 	{ .compatible = "fsl,imx8qxp-pxl2dpi", },
471 	{ /* sentinel */ }
472 };
473 MODULE_DEVICE_TABLE(of, imx8qxp_pxl2dpi_dt_ids);
474 
475 static struct platform_driver imx8qxp_pxl2dpi_bridge_driver = {
476 	.probe	= imx8qxp_pxl2dpi_bridge_probe,
477 	.remove = imx8qxp_pxl2dpi_bridge_remove,
478 	.driver	= {
479 		.of_match_table = imx8qxp_pxl2dpi_dt_ids,
480 		.name = DRIVER_NAME,
481 	},
482 };
483 module_platform_driver(imx8qxp_pxl2dpi_bridge_driver);
484 
485 MODULE_DESCRIPTION("i.MX8QXP pixel link to DPI bridge driver");
486 MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
487 MODULE_LICENSE("GPL v2");
488 MODULE_ALIAS("platform:" DRIVER_NAME);
489