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>

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>
Uwe Kleine-König · Greg Kroah-Hartman
1 parent 328a14e70e
Showing 3 changed files with 126 additions and 0 deletions Side-by-side Diff
drivers/uio/Kconfig
drivers/uio/Makefile
drivers/uio/uio_pdrv.c
@@ -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
 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
+ *
+ * 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);
...	...	@@ -26,6 +26,13 @@
26	26	To compile this driver as a module, choose M here: the module
27	27	will be called uio_cif.
28	28
	29	+config UIO_PDRV
	30	+ tristate "Userspace I/O platform driver"
	31	+ help
	32	+ Generic platform driver for Userspace I/O devices.
	33	+
	34	+ If you don't know what to do here, say N.
	35	+
29	36	config UIO_SMX
30	37	tristate "SMX cryptengine UIO interface"
31	38	default n
1	1	obj-$(CONFIG_UIO) += uio.o
2	2	obj-$(CONFIG_UIO_CIF) += uio_cif.o
	3	+obj-$(CONFIG_UIO_PDRV) += uio_pdrv.o
3	4	obj-$(CONFIG_UIO_SMX) += uio_smx.o
	1	+/*
	2	+ * drivers/uio/uio_pdrv.c
	3	+ *
	4	+ * Copyright (C) 2008 by Digi International Inc.
	5	+ * All rights reserved.
	6	+ *
	7	+ * This program is free software; you can redistribute it and/or modify it
	8	+ * under the terms of the GNU General Public License version 2 as published by
	9	+ * the Free Software Foundation.
	10	+ */
	11	+#include <linux/platform_device.h>
	12	+#include <linux/uio_driver.h>
	13	+#include <linux/stringify.h>
	14	+
	15	+#define DRIVER_NAME "uio"
	16	+
	17	+struct uio_platdata {
	18	+ struct uio_info *uioinfo;
	19	+};
	20	+
	21	+static int uio_pdrv_probe(struct platform_device *pdev)
	22	+{
	23	+ struct uio_info *uioinfo = pdev->dev.platform_data;
	24	+ struct uio_platdata *pdata;
	25	+ struct uio_mem *uiomem;
	26	+ int ret = -ENODEV;
	27	+ int i;
	28	+
	29	+ if (!uioinfo \|\| !uioinfo->name \|\| !uioinfo->version) {
	30	+ dev_dbg(&pdev->dev, "%s: err_uioinfo\n", __func__);
	31	+ goto err_uioinfo;
	32	+ }
	33	+
	34	+ pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
	35	+ if (!pdata) {
	36	+ ret = -ENOMEM;
	37	+ dev_dbg(&pdev->dev, "%s: err_alloc_pdata\n", __func__);
	38	+ goto err_alloc_pdata;
	39	+ }
	40	+
	41	+ pdata->uioinfo = uioinfo;
	42	+
	43	+ uiomem = &uioinfo->mem[0];
	44	+
	45	+ for (i = 0; i < pdev->num_resources; ++i) {
	46	+ struct resource *r = &pdev->resource[i];
	47	+
	48	+ if (r->flags != IORESOURCE_MEM)
	49	+ continue;
	50	+
	51	+ if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) {
	52	+ dev_warn(&pdev->dev, "device has more than "
	53	+ __stringify(MAX_UIO_MAPS)
	54	+ " I/O memory resources.\n");
	55	+ break;
	56	+ }
	57	+
	58	+ uiomem->memtype = UIO_MEM_PHYS;
	59	+ uiomem->addr = r->start;
	60	+ uiomem->size = r->end - r->start + 1;
	61	+ ++uiomem;
	62	+ }
	63	+
	64	+ while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) {
	65	+ uiomem->size = 0;
	66	+ ++uiomem;
	67	+ }
	68	+
	69	+ pdata->uioinfo->priv = pdata;
	70	+
	71	+ ret = uio_register_device(&pdev->dev, pdata->uioinfo);
	72	+
	73	+ if (ret) {
	74	+ kfree(pdata);
	75	+err_alloc_pdata:
	76	+err_uioinfo:
	77	+ return ret;
	78	+ }
	79	+
	80	+ platform_set_drvdata(pdev, pdata);
	81	+
	82	+ return 0;
	83	+}
	84	+
	85	+static int uio_pdrv_remove(struct platform_device *pdev)
	86	+{
	87	+ struct uio_platdata *pdata = platform_get_drvdata(pdev);
	88	+
	89	+ uio_unregister_device(pdata->uioinfo);
	90	+
	91	+ return 0;
	92	+}
	93	+
	94	+static struct platform_driver uio_pdrv = {
	95	+ .probe = uio_pdrv_probe,
	96	+ .remove = uio_pdrv_remove,
	97	+ .driver = {
	98	+ .name = DRIVER_NAME,
	99	+ .owner = THIS_MODULE,
	100	+ },
	101	+};
	102	+
	103	+static int __init uio_pdrv_init(void)
	104	+{
	105	+ return platform_driver_register(&uio_pdrv);
	106	+}
	107	+
	108	+static void __exit uio_pdrv_exit(void)
	109	+{
	110	+ platform_driver_unregister(&uio_pdrv);
	111	+}
	112	+module_init(uio_pdrv_init);
	113	+module_exit(uio_pdrv_exit);
	114	+
	115	+MODULE_AUTHOR("Uwe Kleine-Koenig");
	116	+MODULE_DESCRIPTION("Userspace I/O platform driver");
	117	+MODULE_LICENSE("GPL");
	118	+MODULE_ALIAS("platform:" DRIVER_NAME);