1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ZynqMP DisplayPort Subsystem Driver
4  *
5  * Copyright (C) 2017 - 2020 Xilinx, Inc.
6  *
7  * Authors:
8  * - Hyun Woo Kwon <hyun.kwon@xilinx.com>
9  * - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
10  */
11 
12 #include <linux/clk.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/module.h>
15 #include <linux/of_graph.h>
16 #include <linux/of_reserved_mem.h>
17 #include <linux/platform_device.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/slab.h>
20 
21 #include <drm/drm_atomic_helper.h>
22 #include <drm/drm_bridge.h>
23 #include <drm/drm_modeset_helper.h>
24 #include <drm/drm_module.h>
25 
26 #include "zynqmp_disp.h"
27 #include "zynqmp_dp.h"
28 #include "zynqmp_dpsub.h"
29 #include "zynqmp_kms.h"
30 
31 /* -----------------------------------------------------------------------------
32  * Power Management
33  */
34 
35 static int __maybe_unused zynqmp_dpsub_suspend(struct device *dev)
36 {
37 	struct zynqmp_dpsub *dpsub = dev_get_drvdata(dev);
38 
39 	if (!dpsub->drm)
40 		return 0;
41 
42 	return drm_mode_config_helper_suspend(&dpsub->drm->dev);
43 }
44 
45 static int __maybe_unused zynqmp_dpsub_resume(struct device *dev)
46 {
47 	struct zynqmp_dpsub *dpsub = dev_get_drvdata(dev);
48 
49 	if (!dpsub->drm)
50 		return 0;
51 
52 	return drm_mode_config_helper_resume(&dpsub->drm->dev);
53 }
54 
55 static const struct dev_pm_ops zynqmp_dpsub_pm_ops = {
56 	SET_SYSTEM_SLEEP_PM_OPS(zynqmp_dpsub_suspend, zynqmp_dpsub_resume)
57 };
58 
59 /* -----------------------------------------------------------------------------
60  * DPSUB Configuration
61  */
62 
63 /**
64  * zynqmp_dpsub_audio_enabled - If the audio is enabled
65  * @dpsub: DisplayPort subsystem
66  *
67  * Return if the audio is enabled depending on the audio clock.
68  *
69  * Return: true if audio is enabled, or false.
70  */
71 bool zynqmp_dpsub_audio_enabled(struct zynqmp_dpsub *dpsub)
72 {
73 	return !!dpsub->aud_clk;
74 }
75 
76 /**
77  * zynqmp_dpsub_get_audio_clk_rate - Get the current audio clock rate
78  * @dpsub: DisplayPort subsystem
79  *
80  * Return: the current audio clock rate.
81  */
82 unsigned int zynqmp_dpsub_get_audio_clk_rate(struct zynqmp_dpsub *dpsub)
83 {
84 	if (zynqmp_dpsub_audio_enabled(dpsub))
85 		return 0;
86 	return clk_get_rate(dpsub->aud_clk);
87 }
88 
89 /* -----------------------------------------------------------------------------
90  * Probe & Remove
91  */
92 
93 static int zynqmp_dpsub_init_clocks(struct zynqmp_dpsub *dpsub)
94 {
95 	int ret;
96 
97 	dpsub->apb_clk = devm_clk_get(dpsub->dev, "dp_apb_clk");
98 	if (IS_ERR(dpsub->apb_clk))
99 		return PTR_ERR(dpsub->apb_clk);
100 
101 	ret = clk_prepare_enable(dpsub->apb_clk);
102 	if (ret) {
103 		dev_err(dpsub->dev, "failed to enable the APB clock\n");
104 		return ret;
105 	}
106 
107 	/*
108 	 * Try the live PL video clock, and fall back to the PS clock if the
109 	 * live PL video clock isn't valid.
110 	 */
111 	dpsub->vid_clk = devm_clk_get(dpsub->dev, "dp_live_video_in_clk");
112 	if (!IS_ERR(dpsub->vid_clk))
113 		dpsub->vid_clk_from_ps = false;
114 	else if (PTR_ERR(dpsub->vid_clk) == -EPROBE_DEFER)
115 		return PTR_ERR(dpsub->vid_clk);
116 
117 	if (IS_ERR_OR_NULL(dpsub->vid_clk)) {
118 		dpsub->vid_clk = devm_clk_get(dpsub->dev, "dp_vtc_pixel_clk_in");
119 		if (IS_ERR(dpsub->vid_clk)) {
120 			dev_err(dpsub->dev, "failed to init any video clock\n");
121 			return PTR_ERR(dpsub->vid_clk);
122 		}
123 		dpsub->vid_clk_from_ps = true;
124 	}
125 
126 	/*
127 	 * Try the live PL audio clock, and fall back to the PS clock if the
128 	 * live PL audio clock isn't valid. Missing audio clock disables audio
129 	 * but isn't an error.
130 	 */
131 	dpsub->aud_clk = devm_clk_get(dpsub->dev, "dp_live_audio_aclk");
132 	if (!IS_ERR(dpsub->aud_clk)) {
133 		dpsub->aud_clk_from_ps = false;
134 		return 0;
135 	}
136 
137 	dpsub->aud_clk = devm_clk_get(dpsub->dev, "dp_aud_clk");
138 	if (!IS_ERR(dpsub->aud_clk)) {
139 		dpsub->aud_clk_from_ps = true;
140 		return 0;
141 	}
142 
143 	dev_info(dpsub->dev, "audio disabled due to missing clock\n");
144 	return 0;
145 }
146 
147 static int zynqmp_dpsub_parse_dt(struct zynqmp_dpsub *dpsub)
148 {
149 	struct device_node *np;
150 	unsigned int i;
151 
152 	/*
153 	 * For backward compatibility with old device trees that don't contain
154 	 * ports, consider that only the DP output port is connected if no
155 	 * ports child no exists.
156 	 */
157 	np = of_get_child_by_name(dpsub->dev->of_node, "ports");
158 	of_node_put(np);
159 	if (!np) {
160 		dev_warn(dpsub->dev, "missing ports, update DT bindings\n");
161 		dpsub->connected_ports = BIT(ZYNQMP_DPSUB_PORT_OUT_DP);
162 		dpsub->dma_enabled = true;
163 		return 0;
164 	}
165 
166 	/* Check which ports are connected. */
167 	for (i = 0; i < ZYNQMP_DPSUB_NUM_PORTS; ++i) {
168 		struct device_node *np;
169 
170 		np = of_graph_get_remote_node(dpsub->dev->of_node, i, -1);
171 		if (np) {
172 			dpsub->connected_ports |= BIT(i);
173 			of_node_put(np);
174 		}
175 	}
176 
177 	/* Sanity checks. */
178 	if ((dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO)) &&
179 	    (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))) {
180 		dev_err(dpsub->dev, "only one live video input is supported\n");
181 		return -EINVAL;
182 	}
183 
184 	if ((dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO)) ||
185 	    (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))) {
186 		if (dpsub->vid_clk_from_ps) {
187 			dev_err(dpsub->dev,
188 				"live video input requires PL clock\n");
189 			return -EINVAL;
190 		}
191 	} else {
192 		dpsub->dma_enabled = true;
193 	}
194 
195 	if (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_AUDIO))
196 		dev_warn(dpsub->dev, "live audio unsupported, ignoring\n");
197 
198 	if ((dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_OUT_VIDEO)) ||
199 	    (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_OUT_AUDIO)))
200 		dev_warn(dpsub->dev, "output to PL unsupported, ignoring\n");
201 
202 	if (!(dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_OUT_DP))) {
203 		dev_err(dpsub->dev, "DP output port not connected\n");
204 		return -EINVAL;
205 	}
206 
207 	return 0;
208 }
209 
210 void zynqmp_dpsub_release(struct zynqmp_dpsub *dpsub)
211 {
212 	kfree(dpsub->disp);
213 	kfree(dpsub->dp);
214 	kfree(dpsub);
215 }
216 
217 static int zynqmp_dpsub_probe(struct platform_device *pdev)
218 {
219 	struct zynqmp_dpsub *dpsub;
220 	int ret;
221 
222 	/* Allocate private data. */
223 	dpsub = kzalloc(sizeof(*dpsub), GFP_KERNEL);
224 	if (!dpsub)
225 		return -ENOMEM;
226 
227 	dpsub->dev = &pdev->dev;
228 	platform_set_drvdata(pdev, dpsub);
229 
230 	dma_set_mask(dpsub->dev, DMA_BIT_MASK(ZYNQMP_DISP_MAX_DMA_BIT));
231 
232 	/* Try the reserved memory. Proceed if there's none. */
233 	of_reserved_mem_device_init(&pdev->dev);
234 
235 	ret = zynqmp_dpsub_init_clocks(dpsub);
236 	if (ret < 0)
237 		goto err_mem;
238 
239 	ret = zynqmp_dpsub_parse_dt(dpsub);
240 	if (ret < 0)
241 		goto err_mem;
242 
243 	pm_runtime_enable(&pdev->dev);
244 
245 	/*
246 	 * DP should be probed first so that the zynqmp_disp can set the output
247 	 * format accordingly.
248 	 */
249 	ret = zynqmp_dp_probe(dpsub);
250 	if (ret)
251 		goto err_pm;
252 
253 	ret = zynqmp_disp_probe(dpsub);
254 	if (ret)
255 		goto err_dp;
256 
257 	if (dpsub->dma_enabled) {
258 		ret = zynqmp_dpsub_drm_init(dpsub);
259 		if (ret)
260 			goto err_disp;
261 	} else {
262 		drm_bridge_add(dpsub->bridge);
263 	}
264 
265 	dev_info(&pdev->dev, "ZynqMP DisplayPort Subsystem driver probed");
266 
267 	return 0;
268 
269 err_disp:
270 	zynqmp_disp_remove(dpsub);
271 err_dp:
272 	zynqmp_dp_remove(dpsub);
273 err_pm:
274 	pm_runtime_disable(&pdev->dev);
275 	clk_disable_unprepare(dpsub->apb_clk);
276 err_mem:
277 	of_reserved_mem_device_release(&pdev->dev);
278 	if (!dpsub->drm)
279 		zynqmp_dpsub_release(dpsub);
280 	return ret;
281 }
282 
283 static int zynqmp_dpsub_remove(struct platform_device *pdev)
284 {
285 	struct zynqmp_dpsub *dpsub = platform_get_drvdata(pdev);
286 
287 	if (dpsub->drm)
288 		zynqmp_dpsub_drm_cleanup(dpsub);
289 	else
290 		drm_bridge_remove(dpsub->bridge);
291 
292 	zynqmp_disp_remove(dpsub);
293 	zynqmp_dp_remove(dpsub);
294 
295 	pm_runtime_disable(&pdev->dev);
296 	clk_disable_unprepare(dpsub->apb_clk);
297 	of_reserved_mem_device_release(&pdev->dev);
298 
299 	if (!dpsub->drm)
300 		zynqmp_dpsub_release(dpsub);
301 
302 	return 0;
303 }
304 
305 static void zynqmp_dpsub_shutdown(struct platform_device *pdev)
306 {
307 	struct zynqmp_dpsub *dpsub = platform_get_drvdata(pdev);
308 
309 	if (!dpsub->drm)
310 		return;
311 
312 	drm_atomic_helper_shutdown(&dpsub->drm->dev);
313 }
314 
315 static const struct of_device_id zynqmp_dpsub_of_match[] = {
316 	{ .compatible = "xlnx,zynqmp-dpsub-1.7", },
317 	{ /* end of table */ },
318 };
319 MODULE_DEVICE_TABLE(of, zynqmp_dpsub_of_match);
320 
321 static struct platform_driver zynqmp_dpsub_driver = {
322 	.probe			= zynqmp_dpsub_probe,
323 	.remove			= zynqmp_dpsub_remove,
324 	.shutdown		= zynqmp_dpsub_shutdown,
325 	.driver			= {
326 		.name		= "zynqmp-dpsub",
327 		.pm		= &zynqmp_dpsub_pm_ops,
328 		.of_match_table	= zynqmp_dpsub_of_match,
329 	},
330 };
331 
332 drm_module_platform_driver(zynqmp_dpsub_driver);
333 
334 MODULE_AUTHOR("Xilinx, Inc.");
335 MODULE_DESCRIPTION("ZynqMP DP Subsystem Driver");
336 MODULE_LICENSE("GPL v2");
337