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>
diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index 78e139c..2e9079d 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -26,6 +26,13 @@
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
diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
index 18c4566..e00ce0d 100644
--- a/drivers/uio/Makefile
+++ b/drivers/uio/Makefile
@@ -1,3 +1,4 @@
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
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);