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Commit 4d80d594 authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Greg Kroah-Hartman
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UIO: add generic UIO platform driver 



This patch adds a generic UIO platform driver. It eliminates the need for a
dedicated kernel module for simple platform devices. Users only need to
implement their irq handler in platform code and fill a struct uio_info
there. This helps avoiding code duplication as UIO platform drivers often
share a lot of common code.

Signed-off-by: default avatarUwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Signed-off-by: default avatarHans J. Koch <hjk@linutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 328a14e7

drivers/uio/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -26,6 +26,13 @@ config UIO_CIF 
	  To compile this driver as a module, choose M here: the module

	  will be called uio_cif.



config UIO_PDRV

	tristate "Userspace I/O platform driver"

	help

	  Generic platform driver for Userspace I/O devices.



	  If you don't know what to do here, say N.



config UIO_SMX

	tristate "SMX cryptengine UIO interface"

	default n

drivers/uio/Makefile

+1 −0
Original line number Diff line number Diff line 
obj-$(CONFIG_UIO)	+= uio.o

obj-$(CONFIG_UIO_CIF)	+= uio_cif.o

obj-$(CONFIG_UIO_PDRV)	+= uio_pdrv.o

obj-$(CONFIG_UIO_SMX)	+= uio_smx.o

drivers/uio/uio_pdrv.c

0 → 100644
+118 −0
Original line number Diff line number Diff line 
/*

 * drivers/uio/uio_pdrv.c

 *

 * Copyright (C) 2008 by Digi International Inc.

 * All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 as published by

 * the Free Software Foundation.

 */

#include <linux/platform_device.h>

#include <linux/uio_driver.h>

#include <linux/stringify.h>



#define DRIVER_NAME "uio"



struct uio_platdata {

	struct uio_info *uioinfo;

};



static int uio_pdrv_probe(struct platform_device *pdev)

{

	struct uio_info *uioinfo = pdev->dev.platform_data;

	struct uio_platdata *pdata;

	struct uio_mem *uiomem;

	int ret = -ENODEV;

	int i;



	if (!uioinfo || !uioinfo->name || !uioinfo->version) {

		dev_dbg(&pdev->dev, "%s: err_uioinfo\n", __func__);

		goto err_uioinfo;

	}



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

	if (!pdata) {

		ret = -ENOMEM;

		dev_dbg(&pdev->dev, "%s: err_alloc_pdata\n", __func__);

		goto err_alloc_pdata;

	}



	pdata->uioinfo = uioinfo;



	uiomem = &uioinfo->mem[0];



	for (i = 0; i < pdev->num_resources; ++i) {

		struct resource *r = &pdev->resource[i];



		if (r->flags != IORESOURCE_MEM)

			continue;



		if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) {

			dev_warn(&pdev->dev, "device has more than "

					__stringify(MAX_UIO_MAPS)

					" I/O memory resources.\n");

			break;

		}



		uiomem->memtype = UIO_MEM_PHYS;

		uiomem->addr = r->start;

		uiomem->size = r->end - r->start + 1;

		++uiomem;

	}



	while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) {

		uiomem->size = 0;

		++uiomem;

	}



	pdata->uioinfo->priv = pdata;



	ret = uio_register_device(&pdev->dev, pdata->uioinfo);



	if (ret) {

		kfree(pdata);

err_alloc_pdata:

err_uioinfo:

		return ret;

	}



	platform_set_drvdata(pdev, pdata);



	return 0;

}



static int uio_pdrv_remove(struct platform_device *pdev)

{

	struct uio_platdata *pdata = platform_get_drvdata(pdev);



	uio_unregister_device(pdata->uioinfo);



	return 0;

}



static struct platform_driver uio_pdrv = {

	.probe = uio_pdrv_probe,

	.remove = uio_pdrv_remove,

	.driver = {

		.name = DRIVER_NAME,

		.owner = THIS_MODULE,

	},

};



static int __init uio_pdrv_init(void)

{

	return platform_driver_register(&uio_pdrv);

}



static void __exit uio_pdrv_exit(void)

{

	platform_driver_unregister(&uio_pdrv);

}

module_init(uio_pdrv_init);

module_exit(uio_pdrv_exit);



MODULE_AUTHOR("Uwe Kleine-Koenig");

MODULE_DESCRIPTION("Userspace I/O platform driver");

MODULE_LICENSE("GPL");

MODULE_ALIAS("platform:" DRIVER_NAME);