1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2019-2022 Bootlin
4  * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/clk.h>
9 #include <linux/mfd/syscon.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/of_address.h>
13 #include <linux/of_device.h>
14 #include <linux/of_reserved_mem.h>
15 #include <linux/regmap.h>
16 #include <linux/types.h>
17 
18 #include <drm/drm_atomic_helper.h>
19 #include <drm/drm_drv.h>
20 #include <drm/drm_fbdev_dma.h>
21 #include <drm/drm_gem_dma_helper.h>
22 #include <drm/drm_print.h>
23 
24 #include "logicvc_crtc.h"
25 #include "logicvc_drm.h"
26 #include "logicvc_interface.h"
27 #include "logicvc_mode.h"
28 #include "logicvc_layer.h"
29 #include "logicvc_of.h"
30 #include "logicvc_regs.h"
31 
32 DEFINE_DRM_GEM_DMA_FOPS(logicvc_drm_fops);
33 
34 static int logicvc_drm_gem_dma_dumb_create(struct drm_file *file_priv,
35 					   struct drm_device *drm_dev,
36 					   struct drm_mode_create_dumb *args)
37 {
38 	struct logicvc_drm *logicvc = logicvc_drm(drm_dev);
39 
40 	/* Stride is always fixed to its configuration value. */
41 	args->pitch = logicvc->config.row_stride * DIV_ROUND_UP(args->bpp, 8);
42 
43 	return drm_gem_dma_dumb_create_internal(file_priv, drm_dev, args);
44 }
45 
46 static struct drm_driver logicvc_drm_driver = {
47 	.driver_features		= DRIVER_GEM | DRIVER_MODESET |
48 					  DRIVER_ATOMIC,
49 
50 	.fops				= &logicvc_drm_fops,
51 	.name				= "logicvc-drm",
52 	.desc				= "Xylon LogiCVC DRM driver",
53 	.date				= "20200403",
54 	.major				= 1,
55 	.minor				= 0,
56 
57 	DRM_GEM_DMA_DRIVER_OPS_VMAP_WITH_DUMB_CREATE(logicvc_drm_gem_dma_dumb_create),
58 };
59 
60 static struct regmap_config logicvc_drm_regmap_config = {
61 	.reg_bits	= 32,
62 	.val_bits	= 32,
63 	.reg_stride	= 4,
64 	.name		= "logicvc-drm",
65 };
66 
67 static irqreturn_t logicvc_drm_irq_handler(int irq, void *data)
68 {
69 	struct logicvc_drm *logicvc = data;
70 	irqreturn_t ret = IRQ_NONE;
71 	u32 stat = 0;
72 
73 	/* Get pending interrupt sources. */
74 	regmap_read(logicvc->regmap, LOGICVC_INT_STAT_REG, &stat);
75 
76 	/* Clear all pending interrupt sources. */
77 	regmap_write(logicvc->regmap, LOGICVC_INT_STAT_REG, stat);
78 
79 	if (stat & LOGICVC_INT_STAT_V_SYNC) {
80 		logicvc_crtc_vblank_handler(logicvc);
81 		ret = IRQ_HANDLED;
82 	}
83 
84 	return ret;
85 }
86 
87 static int logicvc_drm_config_parse(struct logicvc_drm *logicvc)
88 {
89 	struct drm_device *drm_dev = &logicvc->drm_dev;
90 	struct device *dev = drm_dev->dev;
91 	struct device_node *of_node = dev->of_node;
92 	struct logicvc_drm_config *config = &logicvc->config;
93 	struct device_node *layers_node;
94 	int ret;
95 
96 	logicvc_of_property_parse_bool(of_node, LOGICVC_OF_PROPERTY_DITHERING,
97 				       &config->dithering);
98 	logicvc_of_property_parse_bool(of_node,
99 				       LOGICVC_OF_PROPERTY_BACKGROUND_LAYER,
100 				       &config->background_layer);
101 	logicvc_of_property_parse_bool(of_node,
102 				       LOGICVC_OF_PROPERTY_LAYERS_CONFIGURABLE,
103 				       &config->layers_configurable);
104 
105 	ret = logicvc_of_property_parse_u32(of_node,
106 					    LOGICVC_OF_PROPERTY_DISPLAY_INTERFACE,
107 					    &config->display_interface);
108 	if (ret)
109 		return ret;
110 
111 	ret = logicvc_of_property_parse_u32(of_node,
112 					    LOGICVC_OF_PROPERTY_DISPLAY_COLORSPACE,
113 					    &config->display_colorspace);
114 	if (ret)
115 		return ret;
116 
117 	ret = logicvc_of_property_parse_u32(of_node,
118 					    LOGICVC_OF_PROPERTY_DISPLAY_DEPTH,
119 					    &config->display_depth);
120 	if (ret)
121 		return ret;
122 
123 	ret = logicvc_of_property_parse_u32(of_node,
124 					    LOGICVC_OF_PROPERTY_ROW_STRIDE,
125 					    &config->row_stride);
126 	if (ret)
127 		return ret;
128 
129 	layers_node = of_get_child_by_name(of_node, "layers");
130 	if (!layers_node) {
131 		drm_err(drm_dev, "Missing non-optional layers node\n");
132 		return -EINVAL;
133 	}
134 
135 	config->layers_count = of_get_child_count(layers_node);
136 	if (!config->layers_count) {
137 		drm_err(drm_dev,
138 			"Missing a non-optional layers children node\n");
139 		return -EINVAL;
140 	}
141 
142 	return 0;
143 }
144 
145 static int logicvc_clocks_prepare(struct logicvc_drm *logicvc)
146 {
147 	struct drm_device *drm_dev = &logicvc->drm_dev;
148 	struct device *dev = drm_dev->dev;
149 
150 	struct {
151 		struct clk **clk;
152 		char *name;
153 		bool optional;
154 	} clocks_map[] = {
155 		{
156 			.clk = &logicvc->vclk,
157 			.name = "vclk",
158 			.optional = false,
159 		},
160 		{
161 			.clk = &logicvc->vclk2,
162 			.name = "vclk2",
163 			.optional = true,
164 		},
165 		{
166 			.clk = &logicvc->lvdsclk,
167 			.name = "lvdsclk",
168 			.optional = true,
169 		},
170 		{
171 			.clk = &logicvc->lvdsclkn,
172 			.name = "lvdsclkn",
173 			.optional = true,
174 		},
175 	};
176 	unsigned int i;
177 	int ret;
178 
179 	for (i = 0; i < ARRAY_SIZE(clocks_map); i++) {
180 		struct clk *clk;
181 
182 		clk = devm_clk_get(dev, clocks_map[i].name);
183 		if (IS_ERR(clk)) {
184 			if (PTR_ERR(clk) == -ENOENT && clocks_map[i].optional)
185 				continue;
186 
187 			drm_err(drm_dev, "Missing non-optional clock %s\n",
188 				clocks_map[i].name);
189 
190 			ret = PTR_ERR(clk);
191 			goto error;
192 		}
193 
194 		ret = clk_prepare_enable(clk);
195 		if (ret) {
196 			drm_err(drm_dev,
197 				"Failed to prepare and enable clock %s\n",
198 				clocks_map[i].name);
199 			goto error;
200 		}
201 
202 		*clocks_map[i].clk = clk;
203 	}
204 
205 	return 0;
206 
207 error:
208 	for (i = 0; i < ARRAY_SIZE(clocks_map); i++) {
209 		if (!*clocks_map[i].clk)
210 			continue;
211 
212 		clk_disable_unprepare(*clocks_map[i].clk);
213 		*clocks_map[i].clk = NULL;
214 	}
215 
216 	return ret;
217 }
218 
219 static int logicvc_clocks_unprepare(struct logicvc_drm *logicvc)
220 {
221 	struct clk **clocks[] = {
222 		&logicvc->vclk,
223 		&logicvc->vclk2,
224 		&logicvc->lvdsclk,
225 		&logicvc->lvdsclkn,
226 	};
227 	unsigned int i;
228 
229 	for (i = 0; i < ARRAY_SIZE(clocks); i++) {
230 		if (!*clocks[i])
231 			continue;
232 
233 		clk_disable_unprepare(*clocks[i]);
234 		*clocks[i] = NULL;
235 	}
236 
237 	return 0;
238 }
239 
240 static const struct logicvc_drm_caps logicvc_drm_caps[] = {
241 	{
242 		.major		= 3,
243 		.layer_address	= false,
244 	},
245 	{
246 		.major		= 4,
247 		.layer_address	= true,
248 	},
249 	{
250 		.major		= 5,
251 		.layer_address	= true,
252 	},
253 };
254 
255 static const struct logicvc_drm_caps *
256 logicvc_drm_caps_match(struct logicvc_drm *logicvc)
257 {
258 	struct drm_device *drm_dev = &logicvc->drm_dev;
259 	const struct logicvc_drm_caps *caps = NULL;
260 	unsigned int major, minor;
261 	char level;
262 	unsigned int i;
263 	u32 version;
264 
265 	regmap_read(logicvc->regmap, LOGICVC_IP_VERSION_REG, &version);
266 
267 	major = FIELD_GET(LOGICVC_IP_VERSION_MAJOR_MASK, version);
268 	minor = FIELD_GET(LOGICVC_IP_VERSION_MINOR_MASK, version);
269 	level = FIELD_GET(LOGICVC_IP_VERSION_LEVEL_MASK, version) + 'a';
270 
271 	for (i = 0; i < ARRAY_SIZE(logicvc_drm_caps); i++) {
272 		if (logicvc_drm_caps[i].major &&
273 		    logicvc_drm_caps[i].major != major)
274 			continue;
275 
276 		if (logicvc_drm_caps[i].minor &&
277 		    logicvc_drm_caps[i].minor != minor)
278 			continue;
279 
280 		if (logicvc_drm_caps[i].level &&
281 		    logicvc_drm_caps[i].level != level)
282 			continue;
283 
284 		caps = &logicvc_drm_caps[i];
285 	}
286 
287 	drm_info(drm_dev, "LogiCVC version %d.%02d.%c\n", major, minor, level);
288 
289 	return caps;
290 }
291 
292 static int logicvc_drm_probe(struct platform_device *pdev)
293 {
294 	struct device_node *of_node = pdev->dev.of_node;
295 	struct device_node *reserved_mem_node;
296 	struct reserved_mem *reserved_mem = NULL;
297 	const struct logicvc_drm_caps *caps;
298 	struct logicvc_drm *logicvc;
299 	struct device *dev = &pdev->dev;
300 	struct drm_device *drm_dev;
301 	struct regmap *regmap = NULL;
302 	struct resource res;
303 	void __iomem *base;
304 	unsigned int preferred_bpp;
305 	int irq;
306 	int ret;
307 
308 	ret = of_reserved_mem_device_init(dev);
309 	if (ret && ret != -ENODEV) {
310 		dev_err(dev, "Failed to init memory region\n");
311 		goto error_early;
312 	}
313 
314 	reserved_mem_node = of_parse_phandle(of_node, "memory-region", 0);
315 	if (reserved_mem_node) {
316 		reserved_mem = of_reserved_mem_lookup(reserved_mem_node);
317 		of_node_put(reserved_mem_node);
318 	}
319 
320 	/* Get regmap from parent if available. */
321 	if (of_node->parent)
322 		regmap = syscon_node_to_regmap(of_node->parent);
323 
324 	/* Register our own regmap otherwise. */
325 	if (IS_ERR_OR_NULL(regmap)) {
326 		ret = of_address_to_resource(of_node, 0, &res);
327 		if (ret) {
328 			dev_err(dev, "Failed to get resource from address\n");
329 			goto error_reserved_mem;
330 		}
331 
332 		base = devm_ioremap_resource(dev, &res);
333 		if (IS_ERR(base)) {
334 			dev_err(dev, "Failed to map I/O base\n");
335 			ret = PTR_ERR(base);
336 			goto error_reserved_mem;
337 		}
338 
339 		logicvc_drm_regmap_config.max_register = resource_size(&res) -
340 							 4;
341 
342 		regmap = devm_regmap_init_mmio(dev, base,
343 					       &logicvc_drm_regmap_config);
344 		if (IS_ERR(regmap)) {
345 			dev_err(dev, "Failed to create regmap for I/O\n");
346 			ret = PTR_ERR(regmap);
347 			goto error_reserved_mem;
348 		}
349 	}
350 
351 	irq = platform_get_irq(pdev, 0);
352 	if (irq < 0) {
353 		ret = -ENODEV;
354 		goto error_reserved_mem;
355 	}
356 
357 	logicvc = devm_drm_dev_alloc(dev, &logicvc_drm_driver,
358 				     struct logicvc_drm, drm_dev);
359 	if (IS_ERR(logicvc)) {
360 		ret = PTR_ERR(logicvc);
361 		goto error_reserved_mem;
362 	}
363 
364 	platform_set_drvdata(pdev, logicvc);
365 	drm_dev = &logicvc->drm_dev;
366 
367 	logicvc->regmap = regmap;
368 	INIT_LIST_HEAD(&logicvc->layers_list);
369 
370 	caps = logicvc_drm_caps_match(logicvc);
371 	if (!caps) {
372 		ret = -EINVAL;
373 		goto error_reserved_mem;
374 	}
375 
376 	logicvc->caps = caps;
377 
378 	if (reserved_mem)
379 		logicvc->reserved_mem_base = reserved_mem->base;
380 
381 	ret = logicvc_clocks_prepare(logicvc);
382 	if (ret) {
383 		drm_err(drm_dev, "Failed to prepare clocks\n");
384 		goto error_reserved_mem;
385 	}
386 
387 	ret = devm_request_irq(dev, irq, logicvc_drm_irq_handler, 0,
388 			       dev_name(dev), logicvc);
389 	if (ret) {
390 		drm_err(drm_dev, "Failed to request IRQ\n");
391 		goto error_clocks;
392 	}
393 
394 	ret = logicvc_drm_config_parse(logicvc);
395 	if (ret && ret != -ENODEV) {
396 		drm_err(drm_dev, "Failed to parse config\n");
397 		goto error_clocks;
398 	}
399 
400 	ret = drmm_mode_config_init(drm_dev);
401 	if (ret) {
402 		drm_err(drm_dev, "Failed to init mode config\n");
403 		goto error_clocks;
404 	}
405 
406 	ret = logicvc_layers_init(logicvc);
407 	if (ret) {
408 		drm_err(drm_dev, "Failed to initialize layers\n");
409 		goto error_clocks;
410 	}
411 
412 	ret = logicvc_crtc_init(logicvc);
413 	if (ret) {
414 		drm_err(drm_dev, "Failed to initialize CRTC\n");
415 		goto error_clocks;
416 	}
417 
418 	logicvc_layers_attach_crtc(logicvc);
419 
420 	ret = logicvc_interface_init(logicvc);
421 	if (ret) {
422 		if (ret != -EPROBE_DEFER)
423 			drm_err(drm_dev, "Failed to initialize interface\n");
424 
425 		goto error_clocks;
426 	}
427 
428 	logicvc_interface_attach_crtc(logicvc);
429 
430 	ret = logicvc_mode_init(logicvc);
431 	if (ret) {
432 		drm_err(drm_dev, "Failed to initialize KMS\n");
433 		goto error_clocks;
434 	}
435 
436 	ret = drm_dev_register(drm_dev, 0);
437 	if (ret) {
438 		drm_err(drm_dev, "Failed to register DRM device\n");
439 		goto error_mode;
440 	}
441 
442 	switch (drm_dev->mode_config.preferred_depth) {
443 	case 16:
444 		preferred_bpp = 16;
445 		break;
446 	case 24:
447 	case 32:
448 	default:
449 		preferred_bpp = 32;
450 		break;
451 	}
452 	drm_fbdev_dma_setup(drm_dev, preferred_bpp);
453 
454 	return 0;
455 
456 error_mode:
457 	logicvc_mode_fini(logicvc);
458 
459 error_clocks:
460 	logicvc_clocks_unprepare(logicvc);
461 
462 error_reserved_mem:
463 	of_reserved_mem_device_release(dev);
464 
465 error_early:
466 	return ret;
467 }
468 
469 static int logicvc_drm_remove(struct platform_device *pdev)
470 {
471 	struct logicvc_drm *logicvc = platform_get_drvdata(pdev);
472 	struct device *dev = &pdev->dev;
473 	struct drm_device *drm_dev = &logicvc->drm_dev;
474 
475 	drm_dev_unregister(drm_dev);
476 	drm_atomic_helper_shutdown(drm_dev);
477 
478 	logicvc_mode_fini(logicvc);
479 
480 	logicvc_clocks_unprepare(logicvc);
481 
482 	of_reserved_mem_device_release(dev);
483 
484 	return 0;
485 }
486 
487 static const struct of_device_id logicvc_drm_of_table[] = {
488 	{ .compatible = "xylon,logicvc-3.02.a-display" },
489 	{ .compatible = "xylon,logicvc-4.01.a-display" },
490 	{},
491 };
492 MODULE_DEVICE_TABLE(of, logicvc_drm_of_table);
493 
494 static struct platform_driver logicvc_drm_platform_driver = {
495 	.probe		= logicvc_drm_probe,
496 	.remove		= logicvc_drm_remove,
497 	.driver		= {
498 		.name		= "logicvc-drm",
499 		.of_match_table	= logicvc_drm_of_table,
500 	},
501 };
502 
503 module_platform_driver(logicvc_drm_platform_driver);
504 
505 MODULE_AUTHOR("Paul Kocialkowski <paul.kocialkowski@bootlin.com>");
506 MODULE_DESCRIPTION("Xylon LogiCVC DRM driver");
507 MODULE_LICENSE("GPL");
508