1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2016 NextThing Co
4  * Copyright (C) 2016-2019 Bootlin
5  *
6  * Author: Maxime Ripard <maxime.ripard@bootlin.com>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
12 #include <linux/mutex.h>
13 #include <linux/of.h>
14 #include <linux/of_device.h>
15 #include <linux/of_graph.h>
16 #include <linux/platform_device.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/reset.h>
19 #include <linux/videodev2.h>
20 
21 #include <media/v4l2-dev.h>
22 #include <media/v4l2-device.h>
23 #include <media/v4l2-fwnode.h>
24 #include <media/v4l2-ioctl.h>
25 #include <media/v4l2-mediabus.h>
26 
27 #include <media/videobuf2-core.h>
28 #include <media/videobuf2-dma-contig.h>
29 
30 #include "sun4i_csi.h"
31 
32 struct sun4i_csi_traits {
33 	unsigned int channels;
34 	unsigned int max_width;
35 	bool has_isp;
36 };
37 
38 static const struct media_entity_operations sun4i_csi_video_entity_ops = {
39 	.link_validate = v4l2_subdev_link_validate,
40 };
41 
42 static int sun4i_csi_notify_bound(struct v4l2_async_notifier *notifier,
43 				  struct v4l2_subdev *subdev,
44 				  struct v4l2_async_subdev *asd)
45 {
46 	struct sun4i_csi *csi = container_of(notifier, struct sun4i_csi,
47 					     notifier);
48 
49 	csi->src_subdev = subdev;
50 	csi->src_pad = media_entity_get_fwnode_pad(&subdev->entity,
51 						   subdev->fwnode,
52 						   MEDIA_PAD_FL_SOURCE);
53 	if (csi->src_pad < 0) {
54 		dev_err(csi->dev, "Couldn't find output pad for subdev %s\n",
55 			subdev->name);
56 		return csi->src_pad;
57 	}
58 
59 	dev_dbg(csi->dev, "Bound %s pad: %d\n", subdev->name, csi->src_pad);
60 	return 0;
61 }
62 
63 static int sun4i_csi_notify_complete(struct v4l2_async_notifier *notifier)
64 {
65 	struct sun4i_csi *csi = container_of(notifier, struct sun4i_csi,
66 					     notifier);
67 	struct v4l2_subdev *subdev = &csi->subdev;
68 	struct video_device *vdev = &csi->vdev;
69 	int ret;
70 
71 	ret = v4l2_device_register_subdev(&csi->v4l, subdev);
72 	if (ret < 0)
73 		return ret;
74 
75 	ret = sun4i_csi_v4l2_register(csi);
76 	if (ret < 0)
77 		return ret;
78 
79 	ret = media_device_register(&csi->mdev);
80 	if (ret)
81 		return ret;
82 
83 	/* Create link from subdev to main device */
84 	ret = media_create_pad_link(&subdev->entity, CSI_SUBDEV_SOURCE,
85 				    &vdev->entity, 0,
86 				    MEDIA_LNK_FL_ENABLED |
87 				    MEDIA_LNK_FL_IMMUTABLE);
88 	if (ret)
89 		goto err_clean_media;
90 
91 	ret = media_create_pad_link(&csi->src_subdev->entity, csi->src_pad,
92 				    &subdev->entity, CSI_SUBDEV_SINK,
93 				    MEDIA_LNK_FL_ENABLED |
94 				    MEDIA_LNK_FL_IMMUTABLE);
95 	if (ret)
96 		goto err_clean_media;
97 
98 	ret = v4l2_device_register_subdev_nodes(&csi->v4l);
99 	if (ret < 0)
100 		goto err_clean_media;
101 
102 	return 0;
103 
104 err_clean_media:
105 	media_device_unregister(&csi->mdev);
106 
107 	return ret;
108 }
109 
110 static const struct v4l2_async_notifier_operations sun4i_csi_notify_ops = {
111 	.bound		= sun4i_csi_notify_bound,
112 	.complete	= sun4i_csi_notify_complete,
113 };
114 
115 static int sun4i_csi_notifier_init(struct sun4i_csi *csi)
116 {
117 	struct v4l2_fwnode_endpoint vep = {
118 		.bus_type = V4L2_MBUS_PARALLEL,
119 	};
120 	struct fwnode_handle *ep;
121 	int ret;
122 
123 	v4l2_async_notifier_init(&csi->notifier);
124 
125 	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csi->dev), 0, 0,
126 					     FWNODE_GRAPH_ENDPOINT_NEXT);
127 	if (!ep)
128 		return -EINVAL;
129 
130 	ret = v4l2_fwnode_endpoint_parse(ep, &vep);
131 	if (ret)
132 		goto out;
133 
134 	csi->bus = vep.bus.parallel;
135 
136 	ret = v4l2_async_notifier_add_fwnode_remote_subdev(&csi->notifier,
137 							   ep, &csi->asd);
138 	if (ret)
139 		goto out;
140 
141 	csi->notifier.ops = &sun4i_csi_notify_ops;
142 
143 out:
144 	fwnode_handle_put(ep);
145 	return ret;
146 }
147 
148 static int sun4i_csi_probe(struct platform_device *pdev)
149 {
150 	struct v4l2_subdev *subdev;
151 	struct video_device *vdev;
152 	struct sun4i_csi *csi;
153 	struct resource *res;
154 	int ret;
155 	int irq;
156 
157 	csi = devm_kzalloc(&pdev->dev, sizeof(*csi), GFP_KERNEL);
158 	if (!csi)
159 		return -ENOMEM;
160 	platform_set_drvdata(pdev, csi);
161 	csi->dev = &pdev->dev;
162 	subdev = &csi->subdev;
163 	vdev = &csi->vdev;
164 
165 	csi->traits = of_device_get_match_data(&pdev->dev);
166 	if (!csi->traits)
167 		return -EINVAL;
168 
169 	/*
170 	 * On Allwinner SoCs, some high memory bandwidth devices do DMA
171 	 * directly over the memory bus (called MBUS), instead of the
172 	 * system bus. The memory bus has a different addressing scheme
173 	 * without the DRAM starting offset.
174 	 *
175 	 * In some cases this can be described by an interconnect in
176 	 * the device tree. In other cases where the hardware is not
177 	 * fully understood and the interconnect is left out of the
178 	 * device tree, fall back to a default offset.
179 	 */
180 	if (of_find_property(csi->dev->of_node, "interconnects", NULL)) {
181 		ret = of_dma_configure(csi->dev, csi->dev->of_node, true);
182 		if (ret)
183 			return ret;
184 	} else {
185 #ifdef PHYS_PFN_OFFSET
186 		csi->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
187 #endif
188 	}
189 
190 	csi->mdev.dev = csi->dev;
191 	strscpy(csi->mdev.model, "Allwinner Video Capture Device",
192 		sizeof(csi->mdev.model));
193 	csi->mdev.hw_revision = 0;
194 	snprintf(csi->mdev.bus_info, sizeof(csi->mdev.bus_info), "platform:%s",
195 		 dev_name(csi->dev));
196 	media_device_init(&csi->mdev);
197 	csi->v4l.mdev = &csi->mdev;
198 
199 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
200 	csi->regs = devm_ioremap_resource(&pdev->dev, res);
201 	if (IS_ERR(csi->regs))
202 		return PTR_ERR(csi->regs);
203 
204 	irq = platform_get_irq(pdev, 0);
205 	if (irq < 0)
206 		return irq;
207 
208 	csi->bus_clk = devm_clk_get(&pdev->dev, "bus");
209 	if (IS_ERR(csi->bus_clk)) {
210 		dev_err(&pdev->dev, "Couldn't get our bus clock\n");
211 		return PTR_ERR(csi->bus_clk);
212 	}
213 
214 	if (csi->traits->has_isp) {
215 		csi->isp_clk = devm_clk_get(&pdev->dev, "isp");
216 		if (IS_ERR(csi->isp_clk)) {
217 			dev_err(&pdev->dev, "Couldn't get our ISP clock\n");
218 			return PTR_ERR(csi->isp_clk);
219 		}
220 	}
221 
222 	csi->ram_clk = devm_clk_get(&pdev->dev, "ram");
223 	if (IS_ERR(csi->ram_clk)) {
224 		dev_err(&pdev->dev, "Couldn't get our ram clock\n");
225 		return PTR_ERR(csi->ram_clk);
226 	}
227 
228 	csi->rst = devm_reset_control_get(&pdev->dev, NULL);
229 	if (IS_ERR(csi->rst)) {
230 		dev_err(&pdev->dev, "Couldn't get our reset line\n");
231 		return PTR_ERR(csi->rst);
232 	}
233 
234 	/* Initialize subdev */
235 	v4l2_subdev_init(subdev, &sun4i_csi_subdev_ops);
236 	subdev->flags = V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
237 	subdev->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
238 	subdev->owner = THIS_MODULE;
239 	snprintf(subdev->name, sizeof(subdev->name), "sun4i-csi-0");
240 	v4l2_set_subdevdata(subdev, csi);
241 
242 	csi->subdev_pads[CSI_SUBDEV_SINK].flags =
243 		MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
244 	csi->subdev_pads[CSI_SUBDEV_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
245 	ret = media_entity_pads_init(&subdev->entity, CSI_SUBDEV_PADS,
246 				     csi->subdev_pads);
247 	if (ret < 0)
248 		return ret;
249 
250 	csi->vdev_pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
251 	vdev->entity.ops = &sun4i_csi_video_entity_ops;
252 	ret = media_entity_pads_init(&vdev->entity, 1, &csi->vdev_pad);
253 	if (ret < 0)
254 		return ret;
255 
256 	ret = sun4i_csi_dma_register(csi, irq);
257 	if (ret)
258 		goto err_clean_pad;
259 
260 	ret = sun4i_csi_notifier_init(csi);
261 	if (ret)
262 		goto err_unregister_media;
263 
264 	ret = v4l2_async_notifier_register(&csi->v4l, &csi->notifier);
265 	if (ret) {
266 		dev_err(csi->dev, "Couldn't register our notifier.\n");
267 		goto err_unregister_media;
268 	}
269 
270 	pm_runtime_enable(&pdev->dev);
271 
272 	return 0;
273 
274 err_unregister_media:
275 	media_device_unregister(&csi->mdev);
276 	sun4i_csi_dma_unregister(csi);
277 
278 err_clean_pad:
279 	media_device_cleanup(&csi->mdev);
280 
281 	return ret;
282 }
283 
284 static int sun4i_csi_remove(struct platform_device *pdev)
285 {
286 	struct sun4i_csi *csi = platform_get_drvdata(pdev);
287 
288 	v4l2_async_notifier_unregister(&csi->notifier);
289 	v4l2_async_notifier_cleanup(&csi->notifier);
290 	media_device_unregister(&csi->mdev);
291 	sun4i_csi_dma_unregister(csi);
292 	media_device_cleanup(&csi->mdev);
293 
294 	return 0;
295 }
296 
297 static const struct sun4i_csi_traits sun4i_a10_csi1_traits = {
298 	.channels = 1,
299 	.max_width = 24,
300 	.has_isp = false,
301 };
302 
303 static const struct sun4i_csi_traits sun7i_a20_csi0_traits = {
304 	.channels = 4,
305 	.max_width = 16,
306 	.has_isp = true,
307 };
308 
309 static const struct of_device_id sun4i_csi_of_match[] = {
310 	{ .compatible = "allwinner,sun4i-a10-csi1", .data = &sun4i_a10_csi1_traits },
311 	{ .compatible = "allwinner,sun7i-a20-csi0", .data = &sun7i_a20_csi0_traits },
312 	{ /* Sentinel */ }
313 };
314 MODULE_DEVICE_TABLE(of, sun4i_csi_of_match);
315 
316 static int __maybe_unused sun4i_csi_runtime_resume(struct device *dev)
317 {
318 	struct sun4i_csi *csi = dev_get_drvdata(dev);
319 
320 	reset_control_deassert(csi->rst);
321 	clk_prepare_enable(csi->bus_clk);
322 	clk_prepare_enable(csi->ram_clk);
323 	clk_set_rate(csi->isp_clk, 80000000);
324 	clk_prepare_enable(csi->isp_clk);
325 
326 	writel(1, csi->regs + CSI_EN_REG);
327 
328 	return 0;
329 }
330 
331 static int __maybe_unused sun4i_csi_runtime_suspend(struct device *dev)
332 {
333 	struct sun4i_csi *csi = dev_get_drvdata(dev);
334 
335 	clk_disable_unprepare(csi->isp_clk);
336 	clk_disable_unprepare(csi->ram_clk);
337 	clk_disable_unprepare(csi->bus_clk);
338 
339 	reset_control_assert(csi->rst);
340 
341 	return 0;
342 }
343 
344 static const struct dev_pm_ops sun4i_csi_pm_ops = {
345 	SET_RUNTIME_PM_OPS(sun4i_csi_runtime_suspend,
346 			   sun4i_csi_runtime_resume,
347 			   NULL)
348 };
349 
350 static struct platform_driver sun4i_csi_driver = {
351 	.probe	= sun4i_csi_probe,
352 	.remove	= sun4i_csi_remove,
353 	.driver	= {
354 		.name		= "sun4i-csi",
355 		.of_match_table	= sun4i_csi_of_match,
356 		.pm		= &sun4i_csi_pm_ops,
357 	},
358 };
359 module_platform_driver(sun4i_csi_driver);
360 
361 MODULE_DESCRIPTION("Allwinner A10 Camera Sensor Interface driver");
362 MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");
363 MODULE_LICENSE("GPL");
364