vip.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Parallel video capture module (VIP) for the Tegra VI.
  4 *
  5 * This file implements the VIP-specific infrastructure.
  6 *
  7 * Copyright (C) 2023 SKIDATA GmbH
  8 * Author: Luca Ceresoli <luca.ceresoli@bootlin.com>
  9 */
 10
 11#include <linux/device.h>
 12#include <linux/host1x.h>
 13#include <linux/module.h>
 14#include <linux/of.h>
 15#include <linux/of_graph.h>
 16#include <linux/platform_device.h>
 17#include <linux/pm_runtime.h>
 18
 19#include <media/v4l2-fwnode.h>
 20
 21#include "vip.h"
 22#include "video.h"
 23
 24static inline struct tegra_vip *host1x_client_to_vip(struct host1x_client *client)
 25{
 26	return container_of(client, struct tegra_vip, client);
 27}
 28
 29static inline struct tegra_vip_channel *subdev_to_vip_channel(struct v4l2_subdev *subdev)
 30{
 31	return container_of(subdev, struct tegra_vip_channel, subdev);
 32}
 33
 34static inline struct tegra_vip *vip_channel_to_vip(struct tegra_vip_channel *chan)
 35{
 36	return container_of(chan, struct tegra_vip, chan);
 37}
 38
 39/* Find the previous subdev in the pipeline (i.e. the one connected to our sink pad) */
 40static struct v4l2_subdev *tegra_vip_channel_get_prev_subdev(struct tegra_vip_channel *chan)
 41{
 42	struct media_pad *remote_pad;
 43
 44	remote_pad = media_pad_remote_pad_first(&chan->pads[TEGRA_VIP_PAD_SINK]);
 45	if (!remote_pad)
 46		return NULL;
 47
 48	return media_entity_to_v4l2_subdev(remote_pad->entity);
 49}
 50
 51static int tegra_vip_enable_stream(struct v4l2_subdev *subdev)
 52{
 53	struct tegra_vip_channel *vip_chan = subdev_to_vip_channel(subdev);
 54	struct tegra_vip *vip = vip_channel_to_vip(vip_chan);
 55	struct v4l2_subdev *prev_subdev = tegra_vip_channel_get_prev_subdev(vip_chan);
 56	int err;
 57
 58	err = pm_runtime_resume_and_get(vip->dev);
 59	if (err)
 60		return dev_err_probe(vip->dev, err, "failed to get runtime PM\n");
 61
 62	err = vip->soc->ops->vip_start_streaming(vip_chan);
 63	if (err < 0)
 64		goto err_start_streaming;
 65
 66	err = v4l2_subdev_call(prev_subdev, video, s_stream, true);
 67	if (err < 0 && err != -ENOIOCTLCMD)
 68		goto err_prev_subdev_start_stream;
 69
 70	return 0;
 71
 72err_prev_subdev_start_stream:
 73err_start_streaming:
 74	pm_runtime_put(vip->dev);
 75	return err;
 76}
 77
 78static int tegra_vip_disable_stream(struct v4l2_subdev *subdev)
 79{
 80	struct tegra_vip_channel *vip_chan = subdev_to_vip_channel(subdev);
 81	struct tegra_vip *vip = vip_channel_to_vip(vip_chan);
 82	struct v4l2_subdev *prev_subdev = tegra_vip_channel_get_prev_subdev(vip_chan);
 83
 84	v4l2_subdev_call(prev_subdev, video, s_stream, false);
 85
 86	pm_runtime_put(vip->dev);
 87
 88	return 0;
 89}
 90
 91static int tegra_vip_s_stream(struct v4l2_subdev *subdev, int enable)
 92{
 93	int err;
 94
 95	if (enable)
 96		err = tegra_vip_enable_stream(subdev);
 97	else
 98		err = tegra_vip_disable_stream(subdev);
 99
100	return err;
101}
102
103static const struct v4l2_subdev_video_ops tegra_vip_video_ops = {
104	.s_stream = tegra_vip_s_stream,
105};
106
107static const struct v4l2_subdev_ops tegra_vip_ops = {
108	.video  = &tegra_vip_video_ops,
109};
110
111static int tegra_vip_channel_of_parse(struct tegra_vip *vip)
112{
113	struct device *dev = vip->dev;
114	struct device_node *np = dev->of_node;
115	struct v4l2_fwnode_endpoint v4l2_ep = {
116		.bus_type = V4L2_MBUS_PARALLEL
117	};
118	struct fwnode_handle *fwh;
119	struct device_node *ep;
120	unsigned int num_pads;
121	int err;
122
123	dev_dbg(dev, "Parsing %pOF", np);
124
125	ep = of_graph_get_endpoint_by_regs(np, 0, 0);
126	if (!ep) {
127		err = -EINVAL;
128		dev_err_probe(dev, err, "%pOF: error getting endpoint node\n", np);
129		goto err_node_put;
130	}
131
132	fwh = of_fwnode_handle(ep);
133	err = v4l2_fwnode_endpoint_parse(fwh, &v4l2_ep);
134	of_node_put(ep);
135	if (err) {
136		dev_err_probe(dev, err, "%pOF: failed to parse v4l2 endpoint\n", np);
137		goto err_node_put;
138	}
139
140	num_pads = of_graph_get_endpoint_count(np);
141	if (num_pads != TEGRA_VIP_PADS_NUM) {
142		err = -EINVAL;
143		dev_err_probe(dev, err, "%pOF: need 2 pads, got %d\n", np, num_pads);
144		goto err_node_put;
145	}
146
147	vip->chan.of_node = of_node_get(np);
148	vip->chan.pads[TEGRA_VIP_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
149	vip->chan.pads[TEGRA_VIP_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
150
151	return 0;
152
153err_node_put:
154	of_node_put(np);
155	return err;
156}
157
158static int tegra_vip_channel_init(struct tegra_vip *vip)
159{
160	struct v4l2_subdev *subdev;
161	int err;
162
163	subdev = &vip->chan.subdev;
164	v4l2_subdev_init(subdev, &tegra_vip_ops);
165	subdev->dev = vip->dev;
166	snprintf(subdev->name, sizeof(subdev->name), "%s",
167		 kbasename(vip->chan.of_node->full_name));
168
169	v4l2_set_subdevdata(subdev, &vip->chan);
170	subdev->fwnode = of_fwnode_handle(vip->chan.of_node);
171	subdev->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
172
173	err = media_entity_pads_init(&subdev->entity, TEGRA_VIP_PADS_NUM, vip->chan.pads);
174	if (err)
175		return dev_err_probe(vip->dev, err, "failed to initialize media entity\n");
176
177	err = v4l2_async_register_subdev(subdev);
178	if (err) {
179		dev_err_probe(vip->dev, err, "failed to register subdev\n");
180		goto err_register_subdev;
181	}
182
183	return 0;
184
185err_register_subdev:
186	media_entity_cleanup(&subdev->entity);
187	return err;
188}
189
190static int tegra_vip_init(struct host1x_client *client)
191{
192	struct tegra_vip *vip = host1x_client_to_vip(client);
193	int err;
194
195	err = tegra_vip_channel_of_parse(vip);
196	if (err)
197		return err;
198
199	err = tegra_vip_channel_init(vip);
200	if (err)
201		goto err_init;
202
203	return 0;
204
205err_init:
206	of_node_put(vip->chan.of_node);
207	return err;
208}
209
210static int tegra_vip_exit(struct host1x_client *client)
211{
212	struct tegra_vip *vip = host1x_client_to_vip(client);
213	struct v4l2_subdev *subdev = &vip->chan.subdev;
214
215	v4l2_async_unregister_subdev(subdev);
216	media_entity_cleanup(&subdev->entity);
217	of_node_put(vip->chan.of_node);
218
219	return 0;
220}
221
222static const struct host1x_client_ops vip_client_ops = {
223	.init = tegra_vip_init,
224	.exit = tegra_vip_exit,
225};
226
227static int tegra_vip_probe(struct platform_device *pdev)
228{
229	struct tegra_vip *vip;
230	int err;
231
232	dev_dbg(&pdev->dev, "Probing VIP \"%s\" from %pOF\n", pdev->name, pdev->dev.of_node);
233
234	vip = devm_kzalloc(&pdev->dev, sizeof(*vip), GFP_KERNEL);
235	if (!vip)
236		return -ENOMEM;
237
238	vip->soc = of_device_get_match_data(&pdev->dev);
239
240	vip->dev = &pdev->dev;
241	platform_set_drvdata(pdev, vip);
242
243	/* initialize host1x interface */
244	INIT_LIST_HEAD(&vip->client.list);
245	vip->client.ops = &vip_client_ops;
246	vip->client.dev = &pdev->dev;
247
248	err = host1x_client_register(&vip->client);
249	if (err)
250		return dev_err_probe(&pdev->dev, err, "failed to register host1x client\n");
251
252	pm_runtime_enable(&pdev->dev);
253
254	return 0;
255}
256
257static void tegra_vip_remove(struct platform_device *pdev)
258{
259	struct tegra_vip *vip = platform_get_drvdata(pdev);
260
261	host1x_client_unregister(&vip->client);
262
263	pm_runtime_disable(&pdev->dev);
264}
265
266#if defined(CONFIG_ARCH_TEGRA_2x_SOC)
267extern const struct tegra_vip_soc tegra20_vip_soc;
268#endif
269
270static const struct of_device_id tegra_vip_of_id_table[] = {
271#if defined(CONFIG_ARCH_TEGRA_2x_SOC)
272	{ .compatible = "nvidia,tegra20-vip", .data = &tegra20_vip_soc },
273#endif
274	{ }
275};
276MODULE_DEVICE_TABLE(of, tegra_vip_of_id_table);
277
278struct platform_driver tegra_vip_driver = {
279	.driver = {
280		.name		= "tegra-vip",
281		.of_match_table	= tegra_vip_of_id_table,
282	},
283	.probe			= tegra_vip_probe,
284	.remove			= tegra_vip_remove,
285};