79 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			79 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-or-later
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| /*
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|  * v4l2-spi - SPI helpers for Video4Linux2
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|  */
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| 
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| #include <linux/module.h>
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| #include <linux/spi/spi.h>
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| #include <media/v4l2-common.h>
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| #include <media/v4l2-device.h>
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| 
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| void v4l2_spi_subdev_unregister(struct v4l2_subdev *sd)
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| {
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| 	struct spi_device *spi = v4l2_get_subdevdata(sd);
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| 
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| 	if (spi && !spi->dev.of_node && !spi->dev.fwnode)
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| 		spi_unregister_device(spi);
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| }
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| 
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| void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
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| 			  const struct v4l2_subdev_ops *ops)
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| {
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| 	v4l2_subdev_init(sd, ops);
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| 	sd->flags |= V4L2_SUBDEV_FL_IS_SPI;
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| 	/* the owner is the same as the spi_device's driver owner */
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| 	sd->owner = spi->dev.driver->owner;
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| 	sd->dev = &spi->dev;
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| 	/* spi_device and v4l2_subdev point to one another */
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| 	v4l2_set_subdevdata(sd, spi);
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| 	spi_set_drvdata(spi, sd);
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| 	/* initialize name */
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| 	snprintf(sd->name, sizeof(sd->name), "%s %s",
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| 		 spi->dev.driver->name, dev_name(&spi->dev));
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| }
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| EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init);
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| 
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| struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
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| 					struct spi_master *master,
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| 					struct spi_board_info *info)
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| {
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| 	struct v4l2_subdev *sd = NULL;
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| 	struct spi_device *spi = NULL;
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| 
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| 	if (!v4l2_dev)
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| 		return NULL;
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| 	if (info->modalias[0])
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| 		request_module(info->modalias);
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| 
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| 	spi = spi_new_device(master, info);
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| 
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| 	if (!spi || !spi->dev.driver)
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| 		goto error;
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| 
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| 	if (!try_module_get(spi->dev.driver->owner))
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| 		goto error;
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| 
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| 	sd = spi_get_drvdata(spi);
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| 
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| 	/*
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| 	 * Register with the v4l2_device which increases the module's
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| 	 * use count as well.
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| 	 */
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| 	if (v4l2_device_register_subdev(v4l2_dev, sd))
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| 		sd = NULL;
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| 
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| 	/* Decrease the module use count to match the first try_module_get. */
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| 	module_put(spi->dev.driver->owner);
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| 
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| error:
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| 	/*
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| 	 * If we have a client but no subdev, then something went wrong and
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| 	 * we must unregister the client.
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| 	 */
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| 	if (!sd)
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| 		spi_unregister_device(spi);
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| 
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| 	return sd;
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| }
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| EXPORT_SYMBOL_GPL(v4l2_spi_new_subdev);
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