1 // SPDX-License-Identifier: GPL-2.0+
2 
3 /*
4  * Copyright 2020 NXP
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/io.h>
11 #include <linux/media-bus-format.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_graph.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm_runtime.h>
17 
18 #include <drm/drm_atomic_state_helper.h>
19 #include <drm/drm_bridge.h>
20 #include <drm/drm_print.h>
21 
22 #define PC_CTRL_REG			0x0
23 #define  PC_COMBINE_ENABLE		BIT(0)
24 #define  PC_DISP_BYPASS(n)		BIT(1 + 21 * (n))
25 #define  PC_DISP_HSYNC_POLARITY(n)	BIT(2 + 11 * (n))
26 #define  PC_DISP_HSYNC_POLARITY_POS(n)	DISP_HSYNC_POLARITY(n)
27 #define  PC_DISP_VSYNC_POLARITY(n)	BIT(3 + 11 * (n))
28 #define  PC_DISP_VSYNC_POLARITY_POS(n)	DISP_VSYNC_POLARITY(n)
29 #define  PC_DISP_DVALID_POLARITY(n)	BIT(4 + 11 * (n))
30 #define  PC_DISP_DVALID_POLARITY_POS(n)	DISP_DVALID_POLARITY(n)
31 #define  PC_VSYNC_MASK_ENABLE		BIT(5)
32 #define  PC_SKIP_MODE			BIT(6)
33 #define  PC_SKIP_NUMBER_MASK		GENMASK(12, 7)
34 #define  PC_SKIP_NUMBER(n)		FIELD_PREP(PC_SKIP_NUMBER_MASK, (n))
35 #define  PC_DISP0_PIX_DATA_FORMAT_MASK	GENMASK(18, 16)
36 #define  PC_DISP0_PIX_DATA_FORMAT(fmt)	\
37 				FIELD_PREP(PC_DISP0_PIX_DATA_FORMAT_MASK, (fmt))
38 #define  PC_DISP1_PIX_DATA_FORMAT_MASK	GENMASK(21, 19)
39 #define  PC_DISP1_PIX_DATA_FORMAT(fmt)	\
40 				FIELD_PREP(PC_DISP1_PIX_DATA_FORMAT_MASK, (fmt))
41 
42 #define PC_SW_RESET_REG			0x20
43 #define  PC_SW_RESET_N			BIT(0)
44 #define  PC_DISP_SW_RESET_N(n)		BIT(1 + (n))
45 #define  PC_FULL_RESET_N		(PC_SW_RESET_N |		\
46 					 PC_DISP_SW_RESET_N(0) |	\
47 					 PC_DISP_SW_RESET_N(1))
48 
49 #define PC_REG_SET			0x4
50 #define PC_REG_CLR			0x8
51 
52 #define DRIVER_NAME			"imx8qxp-pixel-combiner"
53 
54 enum imx8qxp_pc_pix_data_format {
55 	RGB,
56 	YUV444,
57 	YUV422,
58 	SPLIT_RGB,
59 };
60 
61 struct imx8qxp_pc_channel {
62 	struct drm_bridge bridge;
63 	struct drm_bridge *next_bridge;
64 	struct imx8qxp_pc *pc;
65 	unsigned int stream_id;
66 	bool is_available;
67 };
68 
69 struct imx8qxp_pc {
70 	struct device *dev;
71 	struct imx8qxp_pc_channel ch[2];
72 	struct clk *clk_apb;
73 	void __iomem *base;
74 };
75 
imx8qxp_pc_read(struct imx8qxp_pc * pc,unsigned int offset)76 static inline u32 imx8qxp_pc_read(struct imx8qxp_pc *pc, unsigned int offset)
77 {
78 	return readl(pc->base + offset);
79 }
80 
81 static inline void
imx8qxp_pc_write(struct imx8qxp_pc * pc,unsigned int offset,u32 value)82 imx8qxp_pc_write(struct imx8qxp_pc *pc, unsigned int offset, u32 value)
83 {
84 	writel(value, pc->base + offset);
85 }
86 
87 static inline void
imx8qxp_pc_write_set(struct imx8qxp_pc * pc,unsigned int offset,u32 value)88 imx8qxp_pc_write_set(struct imx8qxp_pc *pc, unsigned int offset, u32 value)
89 {
90 	imx8qxp_pc_write(pc, offset + PC_REG_SET, value);
91 }
92 
93 static inline void
imx8qxp_pc_write_clr(struct imx8qxp_pc * pc,unsigned int offset,u32 value)94 imx8qxp_pc_write_clr(struct imx8qxp_pc *pc, unsigned int offset, u32 value)
95 {
96 	imx8qxp_pc_write(pc, offset + PC_REG_CLR, value);
97 }
98 
99 static enum drm_mode_status
imx8qxp_pc_bridge_mode_valid(struct drm_bridge * bridge,const struct drm_display_info * info,const struct drm_display_mode * mode)100 imx8qxp_pc_bridge_mode_valid(struct drm_bridge *bridge,
101 			     const struct drm_display_info *info,
102 			     const struct drm_display_mode *mode)
103 {
104 	if (mode->hdisplay > 2560)
105 		return MODE_BAD_HVALUE;
106 
107 	return MODE_OK;
108 }
109 
imx8qxp_pc_bridge_attach(struct drm_bridge * bridge,enum drm_bridge_attach_flags flags)110 static int imx8qxp_pc_bridge_attach(struct drm_bridge *bridge,
111 				    enum drm_bridge_attach_flags flags)
112 {
113 	struct imx8qxp_pc_channel *ch = bridge->driver_private;
114 	struct imx8qxp_pc *pc = ch->pc;
115 
116 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
117 		DRM_DEV_ERROR(pc->dev,
118 			      "do not support creating a drm_connector\n");
119 		return -EINVAL;
120 	}
121 
122 	if (!bridge->encoder) {
123 		DRM_DEV_ERROR(pc->dev, "missing encoder\n");
124 		return -ENODEV;
125 	}
126 
127 	return drm_bridge_attach(bridge->encoder,
128 				 ch->next_bridge, bridge,
129 				 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
130 }
131 
132 static void
imx8qxp_pc_bridge_mode_set(struct drm_bridge * bridge,const struct drm_display_mode * mode,const struct drm_display_mode * adjusted_mode)133 imx8qxp_pc_bridge_mode_set(struct drm_bridge *bridge,
134 			   const struct drm_display_mode *mode,
135 			   const struct drm_display_mode *adjusted_mode)
136 {
137 	struct imx8qxp_pc_channel *ch = bridge->driver_private;
138 	struct imx8qxp_pc *pc = ch->pc;
139 	u32 val;
140 	int ret;
141 
142 	ret = pm_runtime_get_sync(pc->dev);
143 	if (ret < 0)
144 		DRM_DEV_ERROR(pc->dev,
145 			      "failed to get runtime PM sync: %d\n", ret);
146 
147 	ret = clk_prepare_enable(pc->clk_apb);
148 	if (ret)
149 		DRM_DEV_ERROR(pc->dev, "%s: failed to enable apb clock: %d\n",
150 			      __func__,  ret);
151 
152 	/* HSYNC to pixel link is active low. */
153 	imx8qxp_pc_write_clr(pc, PC_CTRL_REG,
154 			     PC_DISP_HSYNC_POLARITY(ch->stream_id));
155 
156 	/* VSYNC to pixel link is active low. */
157 	imx8qxp_pc_write_clr(pc, PC_CTRL_REG,
158 			     PC_DISP_VSYNC_POLARITY(ch->stream_id));
159 
160 	/* Data enable to pixel link is active high. */
161 	imx8qxp_pc_write_set(pc, PC_CTRL_REG,
162 			     PC_DISP_DVALID_POLARITY(ch->stream_id));
163 
164 	/* Mask the first frame output which may be incomplete. */
165 	imx8qxp_pc_write_set(pc, PC_CTRL_REG, PC_VSYNC_MASK_ENABLE);
166 
167 	/* Only support RGB currently. */
168 	val = imx8qxp_pc_read(pc, PC_CTRL_REG);
169 	if (ch->stream_id == 0) {
170 		val &= ~PC_DISP0_PIX_DATA_FORMAT_MASK;
171 		val |= PC_DISP0_PIX_DATA_FORMAT(RGB);
172 	} else {
173 		val &= ~PC_DISP1_PIX_DATA_FORMAT_MASK;
174 		val |= PC_DISP1_PIX_DATA_FORMAT(RGB);
175 	}
176 	imx8qxp_pc_write(pc, PC_CTRL_REG, val);
177 
178 	/* Only support bypass mode currently. */
179 	imx8qxp_pc_write_set(pc, PC_CTRL_REG, PC_DISP_BYPASS(ch->stream_id));
180 
181 	clk_disable_unprepare(pc->clk_apb);
182 }
183 
184 static void
imx8qxp_pc_bridge_atomic_disable(struct drm_bridge * bridge,struct drm_bridge_state * old_bridge_state)185 imx8qxp_pc_bridge_atomic_disable(struct drm_bridge *bridge,
186 				 struct drm_bridge_state *old_bridge_state)
187 {
188 	struct imx8qxp_pc_channel *ch = bridge->driver_private;
189 	struct imx8qxp_pc *pc = ch->pc;
190 	int ret;
191 
192 	ret = pm_runtime_put(pc->dev);
193 	if (ret < 0)
194 		DRM_DEV_ERROR(pc->dev, "failed to put runtime PM: %d\n", ret);
195 }
196 
197 static const u32 imx8qxp_pc_bus_output_fmts[] = {
198 	MEDIA_BUS_FMT_RGB888_1X36_CPADLO,
199 	MEDIA_BUS_FMT_RGB666_1X36_CPADLO,
200 };
201 
imx8qxp_pc_bus_output_fmt_supported(u32 fmt)202 static bool imx8qxp_pc_bus_output_fmt_supported(u32 fmt)
203 {
204 	int i;
205 
206 	for (i = 0; i < ARRAY_SIZE(imx8qxp_pc_bus_output_fmts); i++) {
207 		if (imx8qxp_pc_bus_output_fmts[i] == fmt)
208 			return true;
209 	}
210 
211 	return false;
212 }
213 
214 static u32 *
imx8qxp_pc_bridge_atomic_get_input_bus_fmts(struct drm_bridge * bridge,struct drm_bridge_state * bridge_state,struct drm_crtc_state * crtc_state,struct drm_connector_state * conn_state,u32 output_fmt,unsigned int * num_input_fmts)215 imx8qxp_pc_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
216 					    struct drm_bridge_state *bridge_state,
217 					    struct drm_crtc_state *crtc_state,
218 					    struct drm_connector_state *conn_state,
219 					    u32 output_fmt,
220 					    unsigned int *num_input_fmts)
221 {
222 	u32 *input_fmts;
223 
224 	if (!imx8qxp_pc_bus_output_fmt_supported(output_fmt))
225 		return NULL;
226 
227 	*num_input_fmts = 1;
228 
229 	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
230 	if (!input_fmts)
231 		return NULL;
232 
233 	switch (output_fmt) {
234 	case MEDIA_BUS_FMT_RGB888_1X36_CPADLO:
235 		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X30_CPADLO;
236 		break;
237 	case MEDIA_BUS_FMT_RGB666_1X36_CPADLO:
238 		input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X30_CPADLO;
239 		break;
240 	default:
241 		kfree(input_fmts);
242 		input_fmts = NULL;
243 		break;
244 	}
245 
246 	return input_fmts;
247 }
248 
249 static u32 *
imx8qxp_pc_bridge_atomic_get_output_bus_fmts(struct drm_bridge * bridge,struct drm_bridge_state * bridge_state,struct drm_crtc_state * crtc_state,struct drm_connector_state * conn_state,unsigned int * num_output_fmts)250 imx8qxp_pc_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
251 					     struct drm_bridge_state *bridge_state,
252 					     struct drm_crtc_state *crtc_state,
253 					     struct drm_connector_state *conn_state,
254 					     unsigned int *num_output_fmts)
255 {
256 	*num_output_fmts = ARRAY_SIZE(imx8qxp_pc_bus_output_fmts);
257 	return kmemdup(imx8qxp_pc_bus_output_fmts,
258 			sizeof(imx8qxp_pc_bus_output_fmts), GFP_KERNEL);
259 }
260 
261 static const struct drm_bridge_funcs imx8qxp_pc_bridge_funcs = {
262 	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
263 	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
264 	.atomic_reset		= drm_atomic_helper_bridge_reset,
265 	.mode_valid		= imx8qxp_pc_bridge_mode_valid,
266 	.attach			= imx8qxp_pc_bridge_attach,
267 	.mode_set		= imx8qxp_pc_bridge_mode_set,
268 	.atomic_disable		= imx8qxp_pc_bridge_atomic_disable,
269 	.atomic_get_input_bus_fmts =
270 				imx8qxp_pc_bridge_atomic_get_input_bus_fmts,
271 	.atomic_get_output_bus_fmts =
272 				imx8qxp_pc_bridge_atomic_get_output_bus_fmts,
273 };
274 
imx8qxp_pc_bridge_probe(struct platform_device * pdev)275 static int imx8qxp_pc_bridge_probe(struct platform_device *pdev)
276 {
277 	struct imx8qxp_pc *pc;
278 	struct imx8qxp_pc_channel *ch;
279 	struct device *dev = &pdev->dev;
280 	struct device_node *np = dev->of_node;
281 	struct device_node *child, *remote;
282 	u32 i;
283 	int ret;
284 
285 	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
286 	if (!pc)
287 		return -ENOMEM;
288 
289 	pc->base = devm_platform_ioremap_resource(pdev, 0);
290 	if (IS_ERR(pc->base))
291 		return PTR_ERR(pc->base);
292 
293 	pc->dev = dev;
294 
295 	pc->clk_apb = devm_clk_get(dev, "apb");
296 	if (IS_ERR(pc->clk_apb)) {
297 		ret = PTR_ERR(pc->clk_apb);
298 		if (ret != -EPROBE_DEFER)
299 			DRM_DEV_ERROR(dev, "failed to get apb clock: %d\n", ret);
300 		return ret;
301 	}
302 
303 	platform_set_drvdata(pdev, pc);
304 	pm_runtime_enable(dev);
305 
306 	for_each_available_child_of_node(np, child) {
307 		ret = of_property_read_u32(child, "reg", &i);
308 		if (ret || i > 1) {
309 			ret = -EINVAL;
310 			DRM_DEV_ERROR(dev,
311 				      "invalid channel(%u) node address\n", i);
312 			goto free_child;
313 		}
314 
315 		ch = &pc->ch[i];
316 		ch->pc = pc;
317 		ch->stream_id = i;
318 
319 		remote = of_graph_get_remote_node(child, 1, 0);
320 		if (!remote) {
321 			ret = -ENODEV;
322 			DRM_DEV_ERROR(dev,
323 				      "channel%u failed to get port1's remote node: %d\n",
324 				      i, ret);
325 			goto free_child;
326 		}
327 
328 		ch->next_bridge = of_drm_find_bridge(remote);
329 		if (!ch->next_bridge) {
330 			of_node_put(remote);
331 			ret = -EPROBE_DEFER;
332 			DRM_DEV_DEBUG_DRIVER(dev,
333 					     "channel%u failed to find next bridge: %d\n",
334 					     i, ret);
335 			goto free_child;
336 		}
337 
338 		of_node_put(remote);
339 
340 		ch->bridge.driver_private = ch;
341 		ch->bridge.funcs = &imx8qxp_pc_bridge_funcs;
342 		ch->bridge.of_node = child;
343 		ch->is_available = true;
344 
345 		drm_bridge_add(&ch->bridge);
346 	}
347 
348 	return 0;
349 
350 free_child:
351 	of_node_put(child);
352 
353 	if (i == 1 && pc->ch[0].next_bridge)
354 		drm_bridge_remove(&pc->ch[0].bridge);
355 
356 	pm_runtime_disable(dev);
357 	return ret;
358 }
359 
imx8qxp_pc_bridge_remove(struct platform_device * pdev)360 static void imx8qxp_pc_bridge_remove(struct platform_device *pdev)
361 {
362 	struct imx8qxp_pc *pc = platform_get_drvdata(pdev);
363 	struct imx8qxp_pc_channel *ch;
364 	int i;
365 
366 	for (i = 0; i < 2; i++) {
367 		ch = &pc->ch[i];
368 
369 		if (!ch->is_available)
370 			continue;
371 
372 		drm_bridge_remove(&ch->bridge);
373 		ch->is_available = false;
374 	}
375 
376 	pm_runtime_disable(&pdev->dev);
377 }
378 
imx8qxp_pc_runtime_suspend(struct device * dev)379 static int __maybe_unused imx8qxp_pc_runtime_suspend(struct device *dev)
380 {
381 	struct platform_device *pdev = to_platform_device(dev);
382 	struct imx8qxp_pc *pc = platform_get_drvdata(pdev);
383 	int ret;
384 
385 	ret = clk_prepare_enable(pc->clk_apb);
386 	if (ret)
387 		DRM_DEV_ERROR(pc->dev, "%s: failed to enable apb clock: %d\n",
388 			      __func__,  ret);
389 
390 	/* Disable pixel combiner by full reset. */
391 	imx8qxp_pc_write_clr(pc, PC_SW_RESET_REG, PC_FULL_RESET_N);
392 
393 	clk_disable_unprepare(pc->clk_apb);
394 
395 	/* Ensure the reset takes effect. */
396 	usleep_range(10, 20);
397 
398 	return ret;
399 }
400 
imx8qxp_pc_runtime_resume(struct device * dev)401 static int __maybe_unused imx8qxp_pc_runtime_resume(struct device *dev)
402 {
403 	struct platform_device *pdev = to_platform_device(dev);
404 	struct imx8qxp_pc *pc = platform_get_drvdata(pdev);
405 	int ret;
406 
407 	ret = clk_prepare_enable(pc->clk_apb);
408 	if (ret) {
409 		DRM_DEV_ERROR(pc->dev, "%s: failed to enable apb clock: %d\n",
410 			      __func__, ret);
411 		return ret;
412 	}
413 
414 	/* out of reset */
415 	imx8qxp_pc_write_set(pc, PC_SW_RESET_REG, PC_FULL_RESET_N);
416 
417 	clk_disable_unprepare(pc->clk_apb);
418 
419 	return ret;
420 }
421 
422 static const struct dev_pm_ops imx8qxp_pc_pm_ops = {
423 	SET_RUNTIME_PM_OPS(imx8qxp_pc_runtime_suspend,
424 			   imx8qxp_pc_runtime_resume, NULL)
425 };
426 
427 static const struct of_device_id imx8qxp_pc_dt_ids[] = {
428 	{ .compatible = "fsl,imx8qm-pixel-combiner", },
429 	{ .compatible = "fsl,imx8qxp-pixel-combiner", },
430 	{ /* sentinel */ }
431 };
432 MODULE_DEVICE_TABLE(of, imx8qxp_pc_dt_ids);
433 
434 static struct platform_driver imx8qxp_pc_bridge_driver = {
435 	.probe	= imx8qxp_pc_bridge_probe,
436 	.remove_new = imx8qxp_pc_bridge_remove,
437 	.driver	= {
438 		.pm = &imx8qxp_pc_pm_ops,
439 		.name = DRIVER_NAME,
440 		.of_match_table = imx8qxp_pc_dt_ids,
441 	},
442 };
443 module_platform_driver(imx8qxp_pc_bridge_driver);
444 
445 MODULE_DESCRIPTION("i.MX8QM/QXP pixel combiner bridge driver");
446 MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
447 MODULE_LICENSE("GPL v2");
448 MODULE_ALIAS("platform:" DRIVER_NAME);
449