[deliverable/linux.git] / drivers / uio / uio_pdrv_genirq.c

/*
 * drivers/uio/uio_pdrv_genirq.c
 *
 * Userspace I/O platform driver with generic IRQ handling code.
 *
 * Copyright (C) 2008 Magnus Damm
 *
 * Based on uio_pdrv.c by Uwe Kleine-Koenig,
 * 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/spinlock.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/stringify.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>

#define DRIVER_NAME "uio_pdrv_genirq"

struct uio_pdrv_genirq_platdata {
	struct uio_info *uioinfo;
	spinlock_t lock;
	unsigned long flags;
	struct platform_device *pdev;
};

/* Bits in uio_pdrv_genirq_platdata.flags */
enum {
	UIO_IRQ_DISABLED = 0,
};

static int uio_pdrv_genirq_open(struct uio_info *info, struct inode *inode)
{
	struct uio_pdrv_genirq_platdata *priv = info->priv;

	/* Wait until the Runtime PM code has woken up the device */
	pm_runtime_get_sync(&priv->pdev->dev);
	return 0;
}

static int uio_pdrv_genirq_release(struct uio_info *info, struct inode *inode)
{
	struct uio_pdrv_genirq_platdata *priv = info->priv;

	/* Tell the Runtime PM code that the device has become idle */
	pm_runtime_put_sync(&priv->pdev->dev);
	return 0;
}

static irqreturn_t uio_pdrv_genirq_handler(int irq, struct uio_info *dev_info)
{
	struct uio_pdrv_genirq_platdata *priv = dev_info->priv;

	/* Just disable the interrupt in the interrupt controller, and
	 * remember the state so we can allow user space to enable it later.
	 */

	spin_lock(&priv->lock);
	if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags))
		disable_irq_nosync(irq);
	spin_unlock(&priv->lock);

	return IRQ_HANDLED;
}

static int uio_pdrv_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on)
{
	struct uio_pdrv_genirq_platdata *priv = dev_info->priv;
	unsigned long flags;

	/* Allow user space to enable and disable the interrupt
	 * in the interrupt controller, but keep track of the
	 * state to prevent per-irq depth damage.
	 *
	 * Serialize this operation to support multiple tasks and concurrency
	 * with irq handler on SMP systems.
	 */

	spin_lock_irqsave(&priv->lock, flags);
	if (irq_on) {
		if (__test_and_clear_bit(UIO_IRQ_DISABLED, &priv->flags))
			enable_irq(dev_info->irq);
	} else {
		if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags))
			disable_irq_nosync(dev_info->irq);
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int uio_pdrv_genirq_probe(struct platform_device *pdev)
{
	struct uio_info *uioinfo = pdev->dev.platform_data;
	struct uio_pdrv_genirq_platdata *priv;
	struct uio_mem *uiomem;
	int ret = -EINVAL;
	int i;

	if (pdev->dev.of_node) {
		/* alloc uioinfo for one device */
		uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL);
		if (!uioinfo) {
			ret = -ENOMEM;
			dev_err(&pdev->dev, "unable to kmalloc\n");
			return ret;
		}
		uioinfo->name = pdev->dev.of_node->name;
		uioinfo->version = "devicetree";
		/* Multiple IRQs are not supported */
	}

	if (!uioinfo || !uioinfo->name || !uioinfo->version) {
		dev_err(&pdev->dev, "missing platform_data\n");
		goto bad0;
	}

	if (uioinfo->handler || uioinfo->irqcontrol ||
	    uioinfo->irq_flags & IRQF_SHARED) {
		dev_err(&pdev->dev, "interrupt configuration error\n");
		goto bad0;
	}

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv) {
		ret = -ENOMEM;
		dev_err(&pdev->dev, "unable to kmalloc\n");
		goto bad0;
	}

	priv->uioinfo = uioinfo;
	spin_lock_init(&priv->lock);
	priv->flags = 0; /* interrupt is enabled to begin with */
	priv->pdev = pdev;

	if (!uioinfo->irq) {
		ret = platform_get_irq(pdev, 0);
		uioinfo->irq = ret;
		if (ret == -ENXIO && pdev->dev.of_node)
			uioinfo->irq = UIO_IRQ_NONE;
		else if (ret < 0) {
			dev_err(&pdev->dev, "failed to get IRQ\n");
			goto bad1;
		}
	}

	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 = resource_size(r);
		uiomem->name = r->name;
		++uiomem;
	}

	while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) {
		uiomem->size = 0;
		++uiomem;
	}

	/* This driver requires no hardware specific kernel code to handle
	 * interrupts. Instead, the interrupt handler simply disables the
	 * interrupt in the interrupt controller. User space is responsible
	 * for performing hardware specific acknowledge and re-enabling of
	 * the interrupt in the interrupt controller.
	 *
	 * Interrupt sharing is not supported.
	 */

	uioinfo->handler = uio_pdrv_genirq_handler;
	uioinfo->irqcontrol = uio_pdrv_genirq_irqcontrol;
	uioinfo->open = uio_pdrv_genirq_open;
	uioinfo->release = uio_pdrv_genirq_release;
	uioinfo->priv = priv;

	/* Enable Runtime PM for this device:
	 * The device starts in suspended state to allow the hardware to be
	 * turned off by default. The Runtime PM bus code should power on the
	 * hardware and enable clocks at open().
	 */
	pm_runtime_enable(&pdev->dev);

	ret = uio_register_device(&pdev->dev, priv->uioinfo);
	if (ret) {
		dev_err(&pdev->dev, "unable to register uio device\n");
		goto bad2;
	}

	platform_set_drvdata(pdev, priv);
	return 0;
 bad2:
	pm_runtime_disable(&pdev->dev);
 bad1:
	kfree(priv);
 bad0:
	/* kfree uioinfo for OF */
	if (pdev->dev.of_node)
		kfree(uioinfo);
	return ret;
}

static int uio_pdrv_genirq_remove(struct platform_device *pdev)
{
	struct uio_pdrv_genirq_platdata *priv = platform_get_drvdata(pdev);

	uio_unregister_device(priv->uioinfo);
	pm_runtime_disable(&pdev->dev);

	priv->uioinfo->handler = NULL;
	priv->uioinfo->irqcontrol = NULL;

	/* kfree uioinfo for OF */
	if (pdev->dev.of_node)
		kfree(priv->uioinfo);

	kfree(priv);
	return 0;
}

static int uio_pdrv_genirq_runtime_nop(struct device *dev)
{
	/* Runtime PM callback shared between ->runtime_suspend()
	 * and ->runtime_resume(). Simply returns success.
	 *
	 * In this driver pm_runtime_get_sync() and pm_runtime_put_sync()
	 * are used at open() and release() time. This allows the
	 * Runtime PM code to turn off power to the device while the
	 * device is unused, ie before open() and after release().
	 *
	 * This Runtime PM callback does not need to save or restore
	 * any registers since user space is responsbile for hardware
	 * register reinitialization after open().
	 */
	return 0;
}

static const struct dev_pm_ops uio_pdrv_genirq_dev_pm_ops = {
	.runtime_suspend = uio_pdrv_genirq_runtime_nop,
	.runtime_resume = uio_pdrv_genirq_runtime_nop,
};

#ifdef CONFIG_OF
static struct of_device_id uio_of_genirq_match[] = {
	{ /* This is filled with module_parm */ },
	{ /* Sentinel */ },
};
MODULE_DEVICE_TABLE(of, uio_of_genirq_match);
module_param_string(of_id, uio_of_genirq_match[0].compatible, 128, 0);
MODULE_PARM_DESC(of_id, "Openfirmware id of the device to be handled by uio");
#endif

static struct platform_driver uio_pdrv_genirq = {
	.probe = uio_pdrv_genirq_probe,
	.remove = uio_pdrv_genirq_remove,
	.driver = {
		.name = DRIVER_NAME,
		.owner = THIS_MODULE,
		.pm = &uio_pdrv_genirq_dev_pm_ops,
		.of_match_table = of_match_ptr(uio_of_genirq_match),
	},
};

module_platform_driver(uio_pdrv_genirq);

MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("Userspace I/O platform driver with generic IRQ handling");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);
Commit	Line	Data
c767db0a MD	1	/*
	2	* drivers/uio/uio_pdrv_genirq.c
	3	*
	4	* Userspace I/O platform driver with generic IRQ handling code.
	5	*
	6	* Copyright (C) 2008 Magnus Damm
	7	*
	8	* Based on uio_pdrv.c by Uwe Kleine-Koenig,
	9	* Copyright (C) 2008 by Digi International Inc.
	10	* All rights reserved.
	11	*
	12	* This program is free software; you can redistribute it and/or modify it
	13	* under the terms of the GNU General Public License version 2 as published by
	14	* the Free Software Foundation.
	15	*/
	16
	17	#include <linux/platform_device.h>
	18	#include <linux/uio_driver.h>
	19	#include <linux/spinlock.h>
	20	#include <linux/bitops.h>
2949ead4	21	#include <linux/module.h>
c767db0a MD	22	#include <linux/interrupt.h>
c767db0a MD	23	#include <linux/stringify.h>
af76756e	24	#include <linux/pm_runtime.h>
5a0e3ad6	25	#include <linux/slab.h>
c767db0a	26
27760f86 HK	27	#include <linux/of.h>
	28	#include <linux/of_platform.h>
	29	#include <linux/of_address.h>
	30
c767db0a MD	31	#define DRIVER_NAME "uio_pdrv_genirq"
	32
	33	struct uio_pdrv_genirq_platdata {
	34	struct uio_info *uioinfo;
	35	spinlock_t lock;
	36	unsigned long flags;
af76756e	37	struct platform_device *pdev;
c767db0a MD	38	};
c767db0a MD	39
34cb2752 VD	40	/* Bits in uio_pdrv_genirq_platdata.flags */
	41	enum {
	42	UIO_IRQ_DISABLED = 0,
	43	};
	44
af76756e MD	45	static int uio_pdrv_genirq_open(struct uio_info info, struct inode inode)
	46	{
	47	struct uio_pdrv_genirq_platdata *priv = info->priv;
	48
	49	/* Wait until the Runtime PM code has woken up the device */
	50	pm_runtime_get_sync(&priv->pdev->dev);
	51	return 0;
	52	}
	53
	54	static int uio_pdrv_genirq_release(struct uio_info info, struct inode inode)
	55	{
	56	struct uio_pdrv_genirq_platdata *priv = info->priv;
	57
	58	/* Tell the Runtime PM code that the device has become idle */
	59	pm_runtime_put_sync(&priv->pdev->dev);
	60	return 0;
	61	}
	62
c767db0a MD	63	static irqreturn_t uio_pdrv_genirq_handler(int irq, struct uio_info *dev_info)
	64	{
	65	struct uio_pdrv_genirq_platdata *priv = dev_info->priv;
	66
	67	/* Just disable the interrupt in the interrupt controller, and
	68	* remember the state so we can allow user space to enable it later.
	69	*/
	70
34cb2752 VD	71	spin_lock(&priv->lock);
34cb2752 VD	72	if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags))
c767db0a	73	disable_irq_nosync(irq);
34cb2752	74	spin_unlock(&priv->lock);
c767db0a MD	75
	76	return IRQ_HANDLED;
	77	}
	78
	79	static int uio_pdrv_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on)
	80	{
	81	struct uio_pdrv_genirq_platdata *priv = dev_info->priv;
	82	unsigned long flags;
	83
	84	/* Allow user space to enable and disable the interrupt
	85	* in the interrupt controller, but keep track of the
	86	* state to prevent per-irq depth damage.
	87	*
34cb2752 VD	88	* Serialize this operation to support multiple tasks and concurrency
34cb2752 VD	89	* with irq handler on SMP systems.
c767db0a MD	90	*/
	91
	92	spin_lock_irqsave(&priv->lock, flags);
	93	if (irq_on) {
34cb2752	94	if (__test_and_clear_bit(UIO_IRQ_DISABLED, &priv->flags))
c767db0a MD	95	enable_irq(dev_info->irq);
c767db0a MD	96	} else {
34cb2752 VD	97	if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags))
34cb2752 VD	98	disable_irq_nosync(dev_info->irq);
c767db0a MD	99	}
	100	spin_unlock_irqrestore(&priv->lock, flags);
	101
	102	return 0;
	103	}
	104
	105	static int uio_pdrv_genirq_probe(struct platform_device *pdev)
	106	{
	107	struct uio_info *uioinfo = pdev->dev.platform_data;
	108	struct uio_pdrv_genirq_platdata *priv;
	109	struct uio_mem *uiomem;
	110	int ret = -EINVAL;
	111	int i;
	112
d5185c4e	113	if (pdev->dev.of_node) {
27760f86 HK	114	/* alloc uioinfo for one device */
	115	uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL);
	116	if (!uioinfo) {
	117	ret = -ENOMEM;
	118	dev_err(&pdev->dev, "unable to kmalloc\n");
e3a3c3a2	119	return ret;
27760f86 HK	120	}
	121	uioinfo->name = pdev->dev.of_node->name;
	122	uioinfo->version = "devicetree";
27760f86	123	/* Multiple IRQs are not supported */
27760f86 HK	124	}
27760f86 HK	125
c767db0a MD	126	if (!uioinfo \|\| !uioinfo->name \|\| !uioinfo->version) {
	127	dev_err(&pdev->dev, "missing platform_data\n");
	128	goto bad0;
	129	}
	130
e543ae89 MF	131	if (uioinfo->handler \|\| uioinfo->irqcontrol \|\|
e543ae89 MF	132	uioinfo->irq_flags & IRQF_SHARED) {
c767db0a MD	133	dev_err(&pdev->dev, "interrupt configuration error\n");
	134	goto bad0;
	135	}
	136
	137	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	138	if (!priv) {
	139	ret = -ENOMEM;
	140	dev_err(&pdev->dev, "unable to kmalloc\n");
	141	goto bad0;
	142	}
	143
	144	priv->uioinfo = uioinfo;
	145	spin_lock_init(&priv->lock);
	146	priv->flags = 0; /* interrupt is enabled to begin with */
af76756e	147	priv->pdev = pdev;
c767db0a	148
94ca629e BS	149	if (!uioinfo->irq) {
94ca629e BS	150	ret = platform_get_irq(pdev, 0);
e3a3c3a2 PM	151	uioinfo->irq = ret;
	152	if (ret == -ENXIO && pdev->dev.of_node)
	153	uioinfo->irq = UIO_IRQ_NONE;
	154	else if (ret < 0) {
94ca629e	155	dev_err(&pdev->dev, "failed to get IRQ\n");
e3a3c3a2	156	goto bad1;
94ca629e	157	}
94ca629e	158	}
e3a3c3a2	159
c767db0a MD	160	uiomem = &uioinfo->mem[0];
	161
	162	for (i = 0; i < pdev->num_resources; ++i) {
	163	struct resource *r = &pdev->resource[i];
	164
	165	if (r->flags != IORESOURCE_MEM)
	166	continue;
	167
	168	if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) {
	169	dev_warn(&pdev->dev, "device has more than "
	170	__stringify(MAX_UIO_MAPS)
	171	" I/O memory resources.\n");
	172	break;
	173	}
	174
	175	uiomem->memtype = UIO_MEM_PHYS;
	176	uiomem->addr = r->start;
28f65c11	177	uiomem->size = resource_size(r);
ecd43c0d	178	uiomem->name = r->name;
c767db0a MD	179	++uiomem;
	180	}
	181
	182	while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) {
	183	uiomem->size = 0;
	184	++uiomem;
	185	}
	186
	187	/* This driver requires no hardware specific kernel code to handle
	188	* interrupts. Instead, the interrupt handler simply disables the
	189	* interrupt in the interrupt controller. User space is responsible
	190	* for performing hardware specific acknowledge and re-enabling of
	191	* the interrupt in the interrupt controller.
	192	*
	193	* Interrupt sharing is not supported.
	194	*/
	195
c767db0a MD	196	uioinfo->handler = uio_pdrv_genirq_handler;
c767db0a MD	197	uioinfo->irqcontrol = uio_pdrv_genirq_irqcontrol;
af76756e MD	198	uioinfo->open = uio_pdrv_genirq_open;
af76756e MD	199	uioinfo->release = uio_pdrv_genirq_release;
c767db0a MD	200	uioinfo->priv = priv;
c767db0a MD	201
af76756e MD	202	/* Enable Runtime PM for this device:
	203	* The device starts in suspended state to allow the hardware to be
	204	* turned off by default. The Runtime PM bus code should power on the
	205	* hardware and enable clocks at open().
	206	*/
	207	pm_runtime_enable(&pdev->dev);
	208
c767db0a MD	209	ret = uio_register_device(&pdev->dev, priv->uioinfo);
	210	if (ret) {
	211	dev_err(&pdev->dev, "unable to register uio device\n");
e3a3c3a2	212	goto bad2;
c767db0a MD	213	}
	214
	215	platform_set_drvdata(pdev, priv);
	216	return 0;
e3a3c3a2 PM	217	bad2:
e3a3c3a2 PM	218	pm_runtime_disable(&pdev->dev);
c767db0a MD	219	bad1:
	220	kfree(priv);
	221	bad0:
27760f86 HK	222	/* kfree uioinfo for OF */
	223	if (pdev->dev.of_node)
	224	kfree(uioinfo);
c767db0a MD	225	return ret;
	226	}
	227
	228	static int uio_pdrv_genirq_remove(struct platform_device *pdev)
	229	{
	230	struct uio_pdrv_genirq_platdata *priv = platform_get_drvdata(pdev);
	231
	232	uio_unregister_device(priv->uioinfo);
af76756e	233	pm_runtime_disable(&pdev->dev);
47296b19 JZ	234
	235	priv->uioinfo->handler = NULL;
	236	priv->uioinfo->irqcontrol = NULL;
	237
27760f86 HK	238	/* kfree uioinfo for OF */
	239	if (pdev->dev.of_node)
	240	kfree(priv->uioinfo);
	241
c767db0a MD	242	kfree(priv);
	243	return 0;
	244	}
	245
af76756e MD	246	static int uio_pdrv_genirq_runtime_nop(struct device *dev)
	247	{
	248	/* Runtime PM callback shared between ->runtime_suspend()
	249	* and ->runtime_resume(). Simply returns success.
	250	*
	251	* In this driver pm_runtime_get_sync() and pm_runtime_put_sync()
	252	* are used at open() and release() time. This allows the
	253	* Runtime PM code to turn off power to the device while the
	254	* device is unused, ie before open() and after release().
	255	*
	256	* This Runtime PM callback does not need to save or restore
	257	* any registers since user space is responsbile for hardware
	258	* register reinitialization after open().
	259	*/
	260	return 0;
	261	}
	262
47145210	263	static const struct dev_pm_ops uio_pdrv_genirq_dev_pm_ops = {
af76756e MD	264	.runtime_suspend = uio_pdrv_genirq_runtime_nop,
	265	.runtime_resume = uio_pdrv_genirq_runtime_nop,
	266	};
	267
27760f86	268	#ifdef CONFIG_OF
05c3e0bb PM	269	static struct of_device_id uio_of_genirq_match[] = {
	270	{ /* This is filled with module_parm */ },
	271	{ /* Sentinel */ },
27760f86 HK	272	};
27760f86 HK	273	MODULE_DEVICE_TABLE(of, uio_of_genirq_match);
05c3e0bb PM	274	module_param_string(of_id, uio_of_genirq_match[0].compatible, 128, 0);
05c3e0bb PM	275	MODULE_PARM_DESC(of_id, "Openfirmware id of the device to be handled by uio");
27760f86 HK	276	#endif
27760f86 HK	277
c767db0a MD	278	static struct platform_driver uio_pdrv_genirq = {
	279	.probe = uio_pdrv_genirq_probe,
	280	.remove = uio_pdrv_genirq_remove,
	281	.driver = {
	282	.name = DRIVER_NAME,
	283	.owner = THIS_MODULE,
af76756e	284	.pm = &uio_pdrv_genirq_dev_pm_ops,
cee4fbd6	285	.of_match_table = of_match_ptr(uio_of_genirq_match),
c767db0a MD	286	},
	287	};
	288
11e3123d	289	module_platform_driver(uio_pdrv_genirq);
c767db0a MD	290
	291	MODULE_AUTHOR("Magnus Damm");
	292	MODULE_DESCRIPTION("Userspace I/O platform driver with generic IRQ handling");
	293	MODULE_LICENSE("GPL v2");
	294	MODULE_ALIAS("platform:" DRIVER_NAME);