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author | Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> | 2008-05-31 09:37:27 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-07-22 04:54:55 (GMT) |
commit | 4d80d59437247075029534adec8d69fce2cfb87a (patch) | |
tree | b694224e588968d58732fa34274c5a594a9e430e /drivers/uio/uio_pdrv.c | |
parent | 328a14e70e7f46997cb50d4258dd93d5377f98c6 (diff) | |
download | linux-4d80d59437247075029534adec8d69fce2cfb87a.tar.xz |
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: 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>
Diffstat (limited to 'drivers/uio/uio_pdrv.c')
-rw-r--r-- | drivers/uio/uio_pdrv.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/drivers/uio/uio_pdrv.c b/drivers/uio/uio_pdrv.c new file mode 100644 index 0000000..5d0d2e8 --- /dev/null +++ b/drivers/uio/uio_pdrv.c @@ -0,0 +1,118 @@ +/* + * 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); |