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Commit 3265edaf authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Greg Kroah-Hartman
Browse files

greybus: Add driver for the camera class protocol 



Integration with the V4L2 camera drivers isn't available yet, a debugfs
interface is exposed instead to call the camera Greybus operations.

The debugfs interface will be kept for module testing purpose in order
to exercise all the protocol operations with various valid and invalid
parameters.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarJacopo Mondi <jacopo.mondi@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
parent e61a2a71

drivers/staging/greybus/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ gb-hid-y := hid.o 
gb-es2-y := es2.o

gb-db3-y := db3-platform.o

gb-audio-codec-y := audio-codec.o

gb-camera-y := camera.o



obj-m += greybus.o

obj-m += gb-phy.o
@@ -42,6 +43,7 @@ obj-m += gb-raw.o 
obj-m += gb-es2.o

obj-m += gb-db3.o

obj-m += gb-audio-codec.o

obj-m += gb-camera.o



KERNELVER		?= $(shell uname -r)

KERNELDIR 		?= /lib/modules/$(KERNELVER)/build

drivers/staging/greybus/camera.c

0 → 100644
+611 −0
Original line number Diff line number Diff line 
/*

 * Greybus Camera protocol driver.

 *

 * Copyright 2015 Google Inc.

 * Copyright 2015 Linaro Ltd.

 *

 * Released under the GPLv2 only.

 */



#include <linux/debugfs.h>

#include <linux/fs.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/string.h>

#include <linux/uaccess.h>

#include <linux/vmalloc.h>



#include "greybus.h"

#include "greybus_protocols.h"



enum gb_camera_debugs_buffer_id {

	GB_CAMERA_DEBUGFS_BUFFER_CAPABILITIES,

	GB_CAMERA_DEBUGFS_BUFFER_STREAMS,

	GB_CAMERA_DEBUGFS_BUFFER_CAPTURE,

	GB_CAMERA_DEBUGFS_BUFFER_FLUSH,

	GB_CAMERA_DEBUGFS_BUFFER_MAX,

};



struct gb_camera_debugfs_buffer {

	char data[PAGE_SIZE];

	size_t length;

};



/**

 * struct gb_camera - A Greybus Camera Device

 * @connection: the greybus connection for camera control

 * @data_connected: whether the data connection has been established

 * @debugfs: debugfs entries for camera protocol operations testing

 */

struct gb_camera {

	struct gb_connection *connection;

	bool data_connected;



	struct {

		struct dentry *root;

		struct gb_camera_debugfs_buffer *buffers;

	} debugfs;

};



struct gb_camera_stream_config {

	unsigned int width;

	unsigned int height;

	unsigned int format;

	unsigned int vc;

	unsigned int dt[2];

	unsigned int max_size;

};



#define ES2_APB_CDSI0_CPORT		16

#define ES2_APB_CDSI1_CPORT		17



#define GB_CAMERA_MAX_SETTINGS_SIZE	8192



#define gcam_dbg(gcam, format...) \

	dev_dbg(&gcam->connection->bundle->dev, format)

#define gcam_info(gcam, format...) \

	dev_info(&gcam->connection->bundle->dev, format)

#define gcam_err(gcam, format...) \

	dev_err(&gcam->connection->bundle->dev, format)



/* -----------------------------------------------------------------------------

 * Camera Protocol Operations

 */



static int gb_camera_configure_streams(struct gb_camera *gcam,

				       unsigned int nstreams,

				       struct gb_camera_stream_config *streams)

{

	struct gb_camera_configure_streams_request *req;

	struct gb_camera_configure_streams_response *resp;

	unsigned int i;

	size_t req_size;

	size_t resp_size;

	int ret;



	if (nstreams > GB_CAMERA_MAX_STREAMS)

		return -EINVAL;



	req_size = sizeof(*req) + nstreams * sizeof(req->config[0]);

	resp_size = sizeof(*resp) + nstreams * sizeof(resp->config[0]);



	req = kmalloc(req_size, GFP_KERNEL);

	resp = kmalloc(resp_size, GFP_KERNEL);

	if (!req || !resp) {

		ret = -ENOMEM;

		goto done;

	}



	req->num_streams = nstreams;

	req->padding = 0;



	for (i = 0; i < nstreams; ++i) {

		struct gb_camera_stream_config_request *cfg = &req->config[i];



		cfg->width = streams[i].width;

		cfg->height = streams[i].height;

		cfg->format = streams[i].format;

		cfg->padding = 0;

	}



	ret = gb_operation_sync(gcam->connection,

				GB_CAMERA_TYPE_CONFIGURE_STREAMS,

				req, req_size, resp, resp_size);

	if (ret < 0)

		return ret;



	if (resp->num_streams > nstreams) {

		gcam_dbg(gcam, "got #streams %u > request %u\n",

			 resp->num_streams, nstreams);

		ret = -EIO;

		goto done;

	}



	if (resp->padding != 0) {

		gcam_dbg(gcam, "response padding != 0");

		ret = -EIO;

		goto done;

	}



	for (i = 0; i < nstreams; ++i) {

		struct gb_camera_stream_config_response *cfg = &resp->config[i];



		streams[i].width = cfg->width;

		streams[i].height = cfg->height;

		streams[i].format = cfg->format;

		streams[i].vc = cfg->virtual_channel;

		streams[i].dt[0] = cfg->data_type[0];

		streams[i].dt[1] = cfg->data_type[1];

		streams[i].max_size = cfg->max_size;



		if (cfg->padding[0] || cfg->padding[1] || cfg->padding[2]) {

			gcam_dbg(gcam, "stream #%u padding != 0", i);

			ret = -EIO;

			goto done;

		}

	}



	ret = resp->num_streams;



done:

	kfree(req);

	kfree(resp);

	return ret;

}



static int gb_camera_capture(struct gb_camera *gcam, u32 request_id,

			     unsigned int streams, unsigned int num_frames,

			     size_t settings_size, const void *settings)

{

	struct gb_camera_capture_request *req;

	size_t req_size;



	if (settings_size > GB_CAMERA_MAX_SETTINGS_SIZE)

		return -EINVAL;



	req_size = sizeof(*req) + settings_size;

	req = kmalloc(req_size, GFP_KERNEL);

	if (!req)

		return -ENOMEM;



	req->request_id = request_id;

	req->streams = streams;

	req->padding = 0;

	req->num_frames = num_frames;

	memcpy(req->settings, settings, settings_size);



	return gb_operation_sync(gcam->connection, GB_CAMERA_TYPE_CAPTURE,

				 req, req_size, NULL, 0);

}



static int gb_camera_flush(struct gb_camera *gcam, u32 *request_id)

{

	struct gb_camera_flush_response resp;

	int ret;



	ret = gb_operation_sync(gcam->connection, GB_CAMERA_TYPE_FLUSH, NULL, 0,

				&resp, sizeof(resp));

	if (ret < 0)

		return ret;



	if (request_id)

		*request_id = resp.request_id;



	return 0;

}



static int gb_camera_event_recv(u8 type, struct gb_operation *op)

{

	struct gb_camera *gcam = op->connection->private;

	struct gb_camera_metadata_request *payload;

	struct gb_message *request;



	if (type != GB_CAMERA_TYPE_METADATA) {

		gcam_err(gcam, "Unsupported unsolicited event: %u\n", type);

		return -EINVAL;

	}



	request = op->request;



	if (request->payload_size < sizeof(*payload)) {

		gcam_err(gcam, "Wrong event size received (%zu < %zu)\n",

			 request->payload_size, sizeof(*payload));

		return -EINVAL;

	}



	payload = request->payload;



	gcam_dbg(gcam, "received metadata for request %u, frame %u, stream %u\n",

		 payload->request_id, payload->frame_number, payload->stream);



	return 0;

}



/* -----------------------------------------------------------------------------

 * DebugFS

 */

static ssize_t gb_camera_debugfs_capabilities(struct gb_camera *gcam,

		char *buf, size_t len)

{

	return len;

}



static ssize_t gb_camera_debugfs_configure_streams(struct gb_camera *gcam,

		char *buf, size_t len)

{

	struct gb_camera_debugfs_buffer *buffer =

		&gcam->debugfs.buffers[GB_CAMERA_DEBUGFS_BUFFER_STREAMS];

	struct gb_camera_stream_config *streams;

	unsigned int nstreams;

	const char *sep = ";";

	unsigned int i;

	char *token;

	int ret;



	/* Retrieve number of streams to configure */

	token = strsep(&buf, sep);

	if (token == NULL)

		return -EINVAL;



	ret = kstrtouint(token, 10, &nstreams);

	if (ret < 0)

		return ret;



	if (nstreams > GB_CAMERA_MAX_STREAMS)

		return -EINVAL;



	/* For each stream to configure parse width, height and format */

	streams = kzalloc(nstreams * sizeof(*streams), GFP_KERNEL);

	if (!streams)

		return -ENOMEM;



	for (i = 0; i < nstreams; ++i) {

		struct gb_camera_stream_config *stream = &streams[i];



		/* width */

		token = strsep(&buf, ";");

		if (token == NULL) {

			ret = -EINVAL;

			goto done;

		}

		ret = kstrtouint(token, 10, &stream->width);

		if (ret < 0)

			goto done;



		/* height */

		token = strsep(&buf, ";");

		if (token == NULL)

			goto done;



		ret = kstrtouint(token, 10, &stream->height);

		if (ret < 0)

			goto done;



		/* Image format code */

		token = strsep(&buf, ";");

		if (token == NULL)

			goto done;



		ret = kstrtouint(token, 16, &stream->format);

		if (ret < 0)

			goto done;

	}



	ret = gb_camera_configure_streams(gcam, nstreams, streams);

	if (ret < 0)

		goto done;



	nstreams = ret;

	buffer->length = sprintf(buffer->data, "%u;", nstreams);



	for (i = 0; i < nstreams; ++i) {

		struct gb_camera_stream_config *stream = &streams[i];



		buffer->length += sprintf(buffer->data + buffer->length,

					  "%u;%u;%u;%u;%u;%u;%u;",

					  stream->width, stream->height,

					  stream->format, stream->vc,

					  stream->dt[0], stream->dt[1],

					  stream->max_size);

	}



	ret = len;



done:

	kfree(streams);

	return ret;

};



static ssize_t gb_camera_debugfs_capture(struct gb_camera *gcam,

		char *buf, size_t len)

{

	unsigned int request_id;

	unsigned int streams_mask;

	unsigned int num_frames;

	char *token;

	int ret;



	/* Request id */

	token = strsep(&buf, ";");

	if (token == NULL)

		return -EINVAL;

	ret = kstrtouint(token, 10, &request_id);

	if (ret < 0)

		return ret;



	/* Stream mask */

	token = strsep(&buf, ";");

	if (token == NULL)

		return -EINVAL;

	ret = kstrtouint(token, 16, &streams_mask);

	if (ret < 0)

		return ret;



	/* number of frames */

	token = strsep(&buf, ";");

	if (token == NULL)

		return -EINVAL;

	ret = kstrtouint(token, 10, &num_frames);

	if (ret < 0)

		return ret;



	ret = gb_camera_capture(gcam, request_id, streams_mask, num_frames, 0,

				NULL);

	if (ret < 0)

		return ret;



	return len;

}



static ssize_t gb_camera_debugfs_flush(struct gb_camera *gcam,

		char *buf, size_t len)

{

	struct gb_camera_debugfs_buffer *buffer =

		&gcam->debugfs.buffers[GB_CAMERA_DEBUGFS_BUFFER_FLUSH];

	unsigned int req_id;

	int ret;



	ret = gb_camera_flush(gcam, &req_id);

	if (ret < 0)

		return ret;



	buffer->length = sprintf(buffer->data, "%u", req_id);



	return len;

}



struct gb_camera_debugfs_entry {

	const char *name;

	unsigned int mask;

	unsigned int buffer;

	ssize_t (*execute)(struct gb_camera *gcam, char *buf, size_t len);

};



static const struct gb_camera_debugfs_entry gb_camera_debugfs_entries[] = {

	{

		.name = "capabilities",

		.mask = S_IFREG | S_IRUGO,

		.buffer = GB_CAMERA_DEBUGFS_BUFFER_CAPABILITIES,

		.execute = gb_camera_debugfs_capabilities,

	}, {

		.name = "configure_streams",

		.mask = S_IFREG | S_IRUGO | S_IWUGO,

		.buffer = GB_CAMERA_DEBUGFS_BUFFER_STREAMS,

		.execute = gb_camera_debugfs_configure_streams,

	}, {

		.name = "capture",

		.mask = S_IFREG | S_IRUGO | S_IWUGO,

		.buffer = GB_CAMERA_DEBUGFS_BUFFER_CAPTURE,

		.execute = gb_camera_debugfs_capture,

	}, {

		.name = "flush",

		.mask = S_IFREG | S_IRUGO | S_IWUGO,

		.buffer = GB_CAMERA_DEBUGFS_BUFFER_FLUSH,

		.execute = gb_camera_debugfs_flush,

	},

};



static ssize_t gb_camera_debugfs_read(struct file *file, char __user *buf,

				      size_t len, loff_t *offset)

{

	const struct gb_camera_debugfs_entry *op = file->private_data;

	struct gb_camera *gcam = file->f_inode->i_private;

	struct gb_camera_debugfs_buffer *buffer;

	ssize_t ret;



	/* For read-only entries the operation is triggered by a read. */

	if (!(op->mask & S_IWUGO)) {

		ret = op->execute(gcam, NULL, 0);

		if (ret < 0)

			return ret;

	}



	buffer = &gcam->debugfs.buffers[op->buffer];



	return simple_read_from_buffer(buf, len, offset, buffer->data,

				       buffer->length);

}



static ssize_t gb_camera_debugfs_write(struct file *file,

				       const char __user *buf, size_t len,

				       loff_t *offset)

{

	const struct gb_camera_debugfs_entry *op = file->private_data;

	struct gb_camera *gcam = file->f_inode->i_private;

	ssize_t ret;

	char *kbuf;



	if (len > 1024)

	       return -EINVAL;



	kbuf = kmalloc(len + 1, GFP_KERNEL);

	if (kbuf == NULL)

		return -ENOMEM;



	if (copy_from_user(kbuf, buf, len)) {

		ret = -EFAULT;

		goto done;

	}



	kbuf[len] = '\0';



	ret = op->execute(gcam, kbuf, len);



done:

	kfree(kbuf);

	return ret;

}



static int gb_camera_debugfs_open(struct inode *inode, struct file *file)

{

	unsigned int i;



	for (i = 0; i < ARRAY_SIZE(gb_camera_debugfs_entries); ++i) {

		const struct gb_camera_debugfs_entry *entry =

			&gb_camera_debugfs_entries[i];



		if (!strcmp(file->f_dentry->d_iname, entry->name)) {

			file->private_data = (void *)entry;

			break;

		}

	}



	return 0;

}



static const struct file_operations gb_camera_debugfs_ops = {

	.open = gb_camera_debugfs_open,

	.read = gb_camera_debugfs_read,

	.write = gb_camera_debugfs_write,

};



static int gb_camera_debugfs_init(struct gb_camera *gcam)

{

	struct gb_connection *connection = gcam->connection;

	char dirname[27];

	unsigned int i;



	/*

	 * Create root debugfs entry and a file entry for each camera operation.

	 */

	snprintf(dirname, 27, "camera-%u.%u", connection->intf->interface_id,

		 connection->bundle->id);



	gcam->debugfs.root = debugfs_create_dir(dirname, gb_debugfs_get());

	if (IS_ERR(gcam->debugfs.root)) {

		gcam_err(gcam, "debugfs root create failed (%ld)\n",

			 PTR_ERR(gcam->debugfs.root));

		return PTR_ERR(gcam->debugfs.root);

	}



	gcam->debugfs.buffers = vmalloc(sizeof(*gcam->debugfs.buffers) *

					GB_CAMERA_DEBUGFS_BUFFER_MAX);

	if (!gcam->debugfs.buffers)

		return -ENOMEM;



	for (i = 0; i < ARRAY_SIZE(gb_camera_debugfs_entries); ++i) {

		const struct gb_camera_debugfs_entry *entry =

			&gb_camera_debugfs_entries[i];

		struct dentry *dentry;



		gcam->debugfs.buffers[i].length = 0;



		dentry = debugfs_create_file(entry->name, entry->mask,

					     gcam->debugfs.root, gcam,

					     &gb_camera_debugfs_ops);

		if (IS_ERR(dentry)) {

			gcam_err(gcam,

				 "debugfs operation %s create failed (%ld)\n",

				 entry->name, PTR_ERR(gcam->debugfs.root));

			return PTR_ERR(dentry);

		}

	}



	return 0;

}



static void gb_camera_debugfs_cleanup(struct gb_camera *gcam)

{

	if (gcam->debugfs.root)

		debugfs_remove_recursive(gcam->debugfs.root);



	vfree(gcam->debugfs.buffers);

}



/* -----------------------------------------------------------------------------

 * Init & Cleanup

 */



static void gb_camera_cleanup(struct gb_camera *gcam)

{

	gb_camera_debugfs_cleanup(gcam);



	if (gcam->data_connected) {

		struct gb_interface *intf = gcam->connection->intf;

		struct gb_svc *svc = gcam->connection->hd->svc;



		gb_svc_connection_destroy(svc, intf->interface_id,

					  ES2_APB_CDSI0_CPORT, svc->ap_intf_id,

					  ES2_APB_CDSI1_CPORT);

	}



	kfree(gcam);

}



static int gb_camera_connection_init(struct gb_connection *connection)

{

	struct gb_svc *svc = connection->hd->svc;

	struct gb_camera *gcam;

	int ret;



	gcam = kzalloc(sizeof(*gcam), GFP_KERNEL);

	if (!gcam)

		return -ENOMEM;



	gcam->connection = connection;

	connection->private = gcam;



	/*

	 * Create the data connection between camera module CDSI0 and APB CDS1.

	 * The CPort IDs are hardcoded by the ES2 bridges.

	 */

	ret = gb_svc_connection_create(svc, connection->intf->interface_id,

				       ES2_APB_CDSI0_CPORT, svc->ap_intf_id,

				       ES2_APB_CDSI1_CPORT, false);

	if (ret < 0)

		goto error;



	gcam->data_connected = true;



	ret = gb_camera_debugfs_init(gcam);

	if (ret < 0)

		goto error;



	return 0;



error:

	gb_camera_cleanup(gcam);

	return ret;

}



static void gb_camera_connection_exit(struct gb_connection *connection)

{

	struct gb_camera *gcam = connection->private;



	gb_camera_cleanup(gcam);

}



static struct gb_protocol camera_protocol = {

	.name			= "camera",

	.id			= GREYBUS_PROTOCOL_CAMERA_MGMT,

	.major			= GB_CAMERA_VERSION_MAJOR,

	.minor			= GB_CAMERA_VERSION_MINOR,

	.connection_init	= gb_camera_connection_init,

	.connection_exit	= gb_camera_connection_exit,

	.request_recv		= gb_camera_event_recv,

};



gb_protocol_driver(&camera_protocol);



MODULE_LICENSE("GPL v2");