4d80d59437
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: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
119 lines
2.4 KiB
C
119 lines
2.4 KiB
C
/*
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* drivers/uio/uio_pdrv.c
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*
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* Copyright (C) 2008 by Digi International Inc.
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/platform_device.h>
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#include <linux/uio_driver.h>
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#include <linux/stringify.h>
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#define DRIVER_NAME "uio"
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struct uio_platdata {
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struct uio_info *uioinfo;
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};
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static int uio_pdrv_probe(struct platform_device *pdev)
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{
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struct uio_info *uioinfo = pdev->dev.platform_data;
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struct uio_platdata *pdata;
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struct uio_mem *uiomem;
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int ret = -ENODEV;
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int i;
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if (!uioinfo || !uioinfo->name || !uioinfo->version) {
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dev_dbg(&pdev->dev, "%s: err_uioinfo\n", __func__);
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goto err_uioinfo;
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}
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pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
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if (!pdata) {
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ret = -ENOMEM;
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dev_dbg(&pdev->dev, "%s: err_alloc_pdata\n", __func__);
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goto err_alloc_pdata;
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}
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pdata->uioinfo = uioinfo;
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uiomem = &uioinfo->mem[0];
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for (i = 0; i < pdev->num_resources; ++i) {
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struct resource *r = &pdev->resource[i];
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if (r->flags != IORESOURCE_MEM)
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continue;
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if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) {
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dev_warn(&pdev->dev, "device has more than "
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__stringify(MAX_UIO_MAPS)
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" I/O memory resources.\n");
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break;
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}
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uiomem->memtype = UIO_MEM_PHYS;
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uiomem->addr = r->start;
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uiomem->size = r->end - r->start + 1;
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++uiomem;
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}
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while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) {
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uiomem->size = 0;
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++uiomem;
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}
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pdata->uioinfo->priv = pdata;
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ret = uio_register_device(&pdev->dev, pdata->uioinfo);
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if (ret) {
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kfree(pdata);
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err_alloc_pdata:
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err_uioinfo:
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return ret;
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}
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platform_set_drvdata(pdev, pdata);
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return 0;
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}
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static int uio_pdrv_remove(struct platform_device *pdev)
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{
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struct uio_platdata *pdata = platform_get_drvdata(pdev);
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uio_unregister_device(pdata->uioinfo);
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return 0;
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}
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static struct platform_driver uio_pdrv = {
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.probe = uio_pdrv_probe,
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.remove = uio_pdrv_remove,
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.driver = {
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.name = DRIVER_NAME,
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.owner = THIS_MODULE,
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},
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};
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static int __init uio_pdrv_init(void)
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{
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return platform_driver_register(&uio_pdrv);
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}
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static void __exit uio_pdrv_exit(void)
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{
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platform_driver_unregister(&uio_pdrv);
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}
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module_init(uio_pdrv_init);
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module_exit(uio_pdrv_exit);
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MODULE_AUTHOR("Uwe Kleine-Koenig");
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MODULE_DESCRIPTION("Userspace I/O platform driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:" DRIVER_NAME);
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