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 	media_device_init(&csi->mdev);
195 	csi->v4l.mdev = &csi->mdev;
196 
197 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
198 	csi->regs = devm_ioremap_resource(&pdev->dev, res);
199 	if (IS_ERR(csi->regs))
200 		return PTR_ERR(csi->regs);
201 
202 	irq = platform_get_irq(pdev, 0);
203 	if (irq < 0)
204 		return irq;
205 
206 	csi->bus_clk = devm_clk_get(&pdev->dev, "bus");
207 	if (IS_ERR(csi->bus_clk)) {
208 		dev_err(&pdev->dev, "Couldn't get our bus clock\n");
209 		return PTR_ERR(csi->bus_clk);
210 	}
211 
212 	if (csi->traits->has_isp) {
213 		csi->isp_clk = devm_clk_get(&pdev->dev, "isp");
214 		if (IS_ERR(csi->isp_clk)) {
215 			dev_err(&pdev->dev, "Couldn't get our ISP clock\n");
216 			return PTR_ERR(csi->isp_clk);
217 		}
218 	}
219 
220 	csi->ram_clk = devm_clk_get(&pdev->dev, "ram");
221 	if (IS_ERR(csi->ram_clk)) {
222 		dev_err(&pdev->dev, "Couldn't get our ram clock\n");
223 		return PTR_ERR(csi->ram_clk);
224 	}
225 
226 	csi->rst = devm_reset_control_get(&pdev->dev, NULL);
227 	if (IS_ERR(csi->rst)) {
228 		dev_err(&pdev->dev, "Couldn't get our reset line\n");
229 		return PTR_ERR(csi->rst);
230 	}
231 
232 	/* Initialize subdev */
233 	v4l2_subdev_init(subdev, &sun4i_csi_subdev_ops);
234 	subdev->flags = V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
235 	subdev->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
236 	subdev->owner = THIS_MODULE;
237 	snprintf(subdev->name, sizeof(subdev->name), "sun4i-csi-0");
238 	v4l2_set_subdevdata(subdev, csi);
239 
240 	csi->subdev_pads[CSI_SUBDEV_SINK].flags =
241 		MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
242 	csi->subdev_pads[CSI_SUBDEV_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
243 	ret = media_entity_pads_init(&subdev->entity, CSI_SUBDEV_PADS,
244 				     csi->subdev_pads);
245 	if (ret < 0)
246 		return ret;
247 
248 	csi->vdev_pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
249 	vdev->entity.ops = &sun4i_csi_video_entity_ops;
250 	ret = media_entity_pads_init(&vdev->entity, 1, &csi->vdev_pad);
251 	if (ret < 0)
252 		return ret;
253 
254 	ret = sun4i_csi_dma_register(csi, irq);
255 	if (ret)
256 		goto err_clean_pad;
257 
258 	ret = sun4i_csi_notifier_init(csi);
259 	if (ret)
260 		goto err_unregister_media;
261 
262 	ret = v4l2_async_notifier_register(&csi->v4l, &csi->notifier);
263 	if (ret) {
264 		dev_err(csi->dev, "Couldn't register our notifier.\n");
265 		goto err_unregister_media;
266 	}
267 
268 	pm_runtime_enable(&pdev->dev);
269 
270 	return 0;
271 
272 err_unregister_media:
273 	media_device_unregister(&csi->mdev);
274 	sun4i_csi_dma_unregister(csi);
275 
276 err_clean_pad:
277 	media_device_cleanup(&csi->mdev);
278 
279 	return ret;
280 }
281 
282 static int sun4i_csi_remove(struct platform_device *pdev)
283 {
284 	struct sun4i_csi *csi = platform_get_drvdata(pdev);
285 
286 	v4l2_async_notifier_unregister(&csi->notifier);
287 	v4l2_async_notifier_cleanup(&csi->notifier);
288 	media_device_unregister(&csi->mdev);
289 	sun4i_csi_dma_unregister(csi);
290 	media_device_cleanup(&csi->mdev);
291 
292 	return 0;
293 }
294 
295 static const struct sun4i_csi_traits sun4i_a10_csi1_traits = {
296 	.channels = 1,
297 	.max_width = 24,
298 	.has_isp = false,
299 };
300 
301 static const struct sun4i_csi_traits sun7i_a20_csi0_traits = {
302 	.channels = 4,
303 	.max_width = 16,
304 	.has_isp = true,
305 };
306 
307 static const struct of_device_id sun4i_csi_of_match[] = {
308 	{ .compatible = "allwinner,sun4i-a10-csi1", .data = &sun4i_a10_csi1_traits },
309 	{ .compatible = "allwinner,sun7i-a20-csi0", .data = &sun7i_a20_csi0_traits },
310 	{ /* Sentinel */ }
311 };
312 MODULE_DEVICE_TABLE(of, sun4i_csi_of_match);
313 
314 static int __maybe_unused sun4i_csi_runtime_resume(struct device *dev)
315 {
316 	struct sun4i_csi *csi = dev_get_drvdata(dev);
317 
318 	reset_control_deassert(csi->rst);
319 	clk_prepare_enable(csi->bus_clk);
320 	clk_prepare_enable(csi->ram_clk);
321 	clk_set_rate(csi->isp_clk, 80000000);
322 	clk_prepare_enable(csi->isp_clk);
323 
324 	writel(1, csi->regs + CSI_EN_REG);
325 
326 	return 0;
327 }
328 
329 static int __maybe_unused sun4i_csi_runtime_suspend(struct device *dev)
330 {
331 	struct sun4i_csi *csi = dev_get_drvdata(dev);
332 
333 	clk_disable_unprepare(csi->isp_clk);
334 	clk_disable_unprepare(csi->ram_clk);
335 	clk_disable_unprepare(csi->bus_clk);
336 
337 	reset_control_assert(csi->rst);
338 
339 	return 0;
340 }
341 
342 static const struct dev_pm_ops sun4i_csi_pm_ops = {
343 	SET_RUNTIME_PM_OPS(sun4i_csi_runtime_suspend,
344 			   sun4i_csi_runtime_resume,
345 			   NULL)
346 };
347 
348 static struct platform_driver sun4i_csi_driver = {
349 	.probe	= sun4i_csi_probe,
350 	.remove	= sun4i_csi_remove,
351 	.driver	= {
352 		.name		= "sun4i-csi",
353 		.of_match_table	= sun4i_csi_of_match,
354 		.pm		= &sun4i_csi_pm_ops,
355 	},
356 };
357 module_platform_driver(sun4i_csi_driver);
358 
359 MODULE_DESCRIPTION("Allwinner A10 Camera Sensor Interface driver");
360 MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");
361 MODULE_LICENSE("GPL");
362