[GitHub/mt8127/android_kernel_alcatel_ttab.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;
};

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.
	 */

	if (!test_and_set_bit(0, &priv->flags))
		disable_irq_nosync(irq);

	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.
	 */

	spin_lock_irqsave(&priv->lock, flags);
	if (irq_on) {
		if (test_and_clear_bit(0, &priv->flags))
			enable_irq(dev_info->irq);
	} else {
		if (!test_and_set_bit(0, &priv->flags))
			disable_irq(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) {
		int irq;

		/* alloc uioinfo for one device */
		uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL);
		if (!uioinfo) {
			ret = -ENOMEM;
			dev_err(&pdev->dev, "unable to kmalloc\n");
			goto bad2;
		}
		uioinfo->name = pdev->dev.of_node->name;
		uioinfo->version = "devicetree";

		/* Multiple IRQs are not supported */
		irq = platform_get_irq(pdev, 0);
		if (irq == -ENXIO)
			uioinfo->irq = UIO_IRQ_NONE;
		else
			uioinfo->irq = irq;
	}

	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);
		if (ret < 0) {
			dev_err(&pdev->dev, "failed to get IRQ\n");
			goto bad0;
		}
		uioinfo->irq = ret;
	}
	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 bad1;
	}

	platform_set_drvdata(pdev, priv);
	return 0;
 bad1:
	kfree(priv);
	pm_runtime_disable(&pdev->dev);
 bad0:
	/* kfree uioinfo for OF */
	if (pdev->dev.of_node)
		kfree(uioinfo);
 bad2:
	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 const struct of_device_id uio_of_genirq_match[] = {
	{ /* empty for now */ },
};
MODULE_DEVICE_TABLE(of, uio_of_genirq_match);
#else
# define uio_of_genirq_match NULL
#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 = 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
af76756e MD	40	static int uio_pdrv_genirq_open(struct uio_info info, struct inode inode)
	41	{
	42	struct uio_pdrv_genirq_platdata *priv = info->priv;
	43
	44	/* Wait until the Runtime PM code has woken up the device */
	45	pm_runtime_get_sync(&priv->pdev->dev);
	46	return 0;
	47	}
	48
	49	static int uio_pdrv_genirq_release(struct uio_info info, struct inode inode)
	50	{
	51	struct uio_pdrv_genirq_platdata *priv = info->priv;
	52
	53	/* Tell the Runtime PM code that the device has become idle */
	54	pm_runtime_put_sync(&priv->pdev->dev);
	55	return 0;
	56	}
	57
c767db0a MD	58	static irqreturn_t uio_pdrv_genirq_handler(int irq, struct uio_info *dev_info)
	59	{
	60	struct uio_pdrv_genirq_platdata *priv = dev_info->priv;
	61
	62	/* Just disable the interrupt in the interrupt controller, and
	63	* remember the state so we can allow user space to enable it later.
	64	*/
	65
	66	if (!test_and_set_bit(0, &priv->flags))
	67	disable_irq_nosync(irq);
	68
	69	return IRQ_HANDLED;
	70	}
	71
	72	static int uio_pdrv_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on)
	73	{
	74	struct uio_pdrv_genirq_platdata *priv = dev_info->priv;
	75	unsigned long flags;
	76
	77	/* Allow user space to enable and disable the interrupt
	78	* in the interrupt controller, but keep track of the
	79	* state to prevent per-irq depth damage.
	80	*
	81	* Serialize this operation to support multiple tasks.
	82	*/
	83
	84	spin_lock_irqsave(&priv->lock, flags);
	85	if (irq_on) {
	86	if (test_and_clear_bit(0, &priv->flags))
	87	enable_irq(dev_info->irq);
	88	} else {
	89	if (!test_and_set_bit(0, &priv->flags))
	90	disable_irq(dev_info->irq);
	91	}
	92	spin_unlock_irqrestore(&priv->lock, flags);
	93
	94	return 0;
	95	}
	96
	97	static int uio_pdrv_genirq_probe(struct platform_device *pdev)
	98	{
	99	struct uio_info *uioinfo = pdev->dev.platform_data;
	100	struct uio_pdrv_genirq_platdata *priv;
	101	struct uio_mem *uiomem;
	102	int ret = -EINVAL;
	103	int i;
	104
d5185c4e	105	if (pdev->dev.of_node) {
27760f86 HK	106	int irq;
	107
	108	/* alloc uioinfo for one device */
	109	uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL);
	110	if (!uioinfo) {
	111	ret = -ENOMEM;
	112	dev_err(&pdev->dev, "unable to kmalloc\n");
	113	goto bad2;
	114	}
	115	uioinfo->name = pdev->dev.of_node->name;
	116	uioinfo->version = "devicetree";
	117
	118	/* Multiple IRQs are not supported */
	119	irq = platform_get_irq(pdev, 0);
	120	if (irq == -ENXIO)
	121	uioinfo->irq = UIO_IRQ_NONE;
	122	else
	123	uioinfo->irq = irq;
	124	}
	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) {
	150	ret = platform_get_irq(pdev, 0);
	151	if (ret < 0) {
	152	dev_err(&pdev->dev, "failed to get IRQ\n");
	153	goto bad0;
	154	}
	155	uioinfo->irq = ret;
	156	}
c767db0a MD	157	uiomem = &uioinfo->mem[0];
	158
	159	for (i = 0; i < pdev->num_resources; ++i) {
	160	struct resource *r = &pdev->resource[i];
	161
	162	if (r->flags != IORESOURCE_MEM)
	163	continue;
	164
	165	if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) {
	166	dev_warn(&pdev->dev, "device has more than "
	167	__stringify(MAX_UIO_MAPS)
	168	" I/O memory resources.\n");
	169	break;
	170	}
	171
	172	uiomem->memtype = UIO_MEM_PHYS;
	173	uiomem->addr = r->start;
28f65c11	174	uiomem->size = resource_size(r);
ecd43c0d	175	uiomem->name = r->name;
c767db0a MD	176	++uiomem;
	177	}
	178
	179	while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) {
	180	uiomem->size = 0;
	181	++uiomem;
	182	}
	183
	184	/* This driver requires no hardware specific kernel code to handle
	185	* interrupts. Instead, the interrupt handler simply disables the
	186	* interrupt in the interrupt controller. User space is responsible
	187	* for performing hardware specific acknowledge and re-enabling of
	188	* the interrupt in the interrupt controller.
	189	*
	190	* Interrupt sharing is not supported.
	191	*/
	192
c767db0a MD	193	uioinfo->handler = uio_pdrv_genirq_handler;
c767db0a MD	194	uioinfo->irqcontrol = uio_pdrv_genirq_irqcontrol;
af76756e MD	195	uioinfo->open = uio_pdrv_genirq_open;
af76756e MD	196	uioinfo->release = uio_pdrv_genirq_release;
c767db0a MD	197	uioinfo->priv = priv;
c767db0a MD	198
af76756e MD	199	/* Enable Runtime PM for this device:
	200	* The device starts in suspended state to allow the hardware to be
	201	* turned off by default. The Runtime PM bus code should power on the
	202	* hardware and enable clocks at open().
	203	*/
	204	pm_runtime_enable(&pdev->dev);
	205
c767db0a MD	206	ret = uio_register_device(&pdev->dev, priv->uioinfo);
	207	if (ret) {
	208	dev_err(&pdev->dev, "unable to register uio device\n");
	209	goto bad1;
	210	}
	211
	212	platform_set_drvdata(pdev, priv);
	213	return 0;
	214	bad1:
	215	kfree(priv);
68fb2e49	216	pm_runtime_disable(&pdev->dev);
c767db0a	217	bad0:
27760f86 HK	218	/* kfree uioinfo for OF */
	219	if (pdev->dev.of_node)
	220	kfree(uioinfo);
	221	bad2:
c767db0a MD	222	return ret;
	223	}
	224
	225	static int uio_pdrv_genirq_remove(struct platform_device *pdev)
	226	{
	227	struct uio_pdrv_genirq_platdata *priv = platform_get_drvdata(pdev);
	228
	229	uio_unregister_device(priv->uioinfo);
af76756e	230	pm_runtime_disable(&pdev->dev);
47296b19 JZ	231
	232	priv->uioinfo->handler = NULL;
	233	priv->uioinfo->irqcontrol = NULL;
	234
27760f86 HK	235	/* kfree uioinfo for OF */
	236	if (pdev->dev.of_node)
	237	kfree(priv->uioinfo);
	238
c767db0a MD	239	kfree(priv);
	240	return 0;
	241	}
	242
af76756e MD	243	static int uio_pdrv_genirq_runtime_nop(struct device *dev)
	244	{
	245	/* Runtime PM callback shared between ->runtime_suspend()
	246	* and ->runtime_resume(). Simply returns success.
	247	*
	248	* In this driver pm_runtime_get_sync() and pm_runtime_put_sync()
	249	* are used at open() and release() time. This allows the
	250	* Runtime PM code to turn off power to the device while the
	251	* device is unused, ie before open() and after release().
	252	*
	253	* This Runtime PM callback does not need to save or restore
	254	* any registers since user space is responsbile for hardware
	255	* register reinitialization after open().
	256	*/
	257	return 0;
	258	}
	259
47145210	260	static const struct dev_pm_ops uio_pdrv_genirq_dev_pm_ops = {
af76756e MD	261	.runtime_suspend = uio_pdrv_genirq_runtime_nop,
	262	.runtime_resume = uio_pdrv_genirq_runtime_nop,
	263	};
	264
27760f86	265	#ifdef CONFIG_OF
9245acd2	266	static const struct of_device_id uio_of_genirq_match[] = {
27760f86 HK	267	{ /* empty for now */ },
	268	};
	269	MODULE_DEVICE_TABLE(of, uio_of_genirq_match);
	270	#else
	271	# define uio_of_genirq_match NULL
	272	#endif
	273
c767db0a MD	274	static struct platform_driver uio_pdrv_genirq = {
	275	.probe = uio_pdrv_genirq_probe,
	276	.remove = uio_pdrv_genirq_remove,
	277	.driver = {
	278	.name = DRIVER_NAME,
	279	.owner = THIS_MODULE,
af76756e	280	.pm = &uio_pdrv_genirq_dev_pm_ops,
27760f86	281	.of_match_table = uio_of_genirq_match,
c767db0a MD	282	},
	283	};
	284
11e3123d	285	module_platform_driver(uio_pdrv_genirq);
c767db0a MD	286
	287	MODULE_AUTHOR("Magnus Damm");
	288	MODULE_DESCRIPTION("Userspace I/O platform driver with generic IRQ handling");
	289	MODULE_LICENSE("GPL v2");
	290	MODULE_ALIAS("platform:" DRIVER_NAME);