[linux.git] / drivers / gpio / gpio-grgpio.c

/*
 * Driver for Aeroflex Gaisler GRGPIO General Purpose I/O cores.
 *
 * 2013 (c) Aeroflex Gaisler AB
 *
 * This driver supports the GRGPIO GPIO core available in the GRLIB VHDL
 * IP core library.
 *
 * Full documentation of the GRGPIO core can be found here:
 * http://www.gaisler.com/products/grlib/grip.pdf
 *
 * See "Documentation/devicetree/bindings/gpio/gpio-grgpio.txt" for
 * information on open firmware properties.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * Contributors: Andreas Larsson <[email protected]>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/gpio/driver.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/bitops.h>

#define GRGPIO_MAX_NGPIO 32

#define GRGPIO_DATA		0x00
#define GRGPIO_OUTPUT		0x04
#define GRGPIO_DIR		0x08
#define GRGPIO_IMASK		0x0c
#define GRGPIO_IPOL		0x10
#define GRGPIO_IEDGE		0x14
#define GRGPIO_BYPASS		0x18
#define GRGPIO_IMAP_BASE	0x20

/* Structure for an irq of the core - called an underlying irq */
struct grgpio_uirq {
	u8 refcnt; /* Reference counter to manage requesting/freeing of uirq */
	u8 uirq; /* Underlying irq of the gpio driver */
};

/*
 * Structure for an irq of a gpio line handed out by this driver. The index is
 * used to map to the corresponding underlying irq.
 */
struct grgpio_lirq {
	s8 index; /* Index into struct grgpio_priv's uirqs, or -1 */
	u8 irq; /* irq for the gpio line */
};

struct grgpio_priv {
	struct gpio_chip gc;
	void __iomem *regs;
	struct device *dev;

	u32 imask; /* irq mask shadow register */

	/*
	 * The grgpio core can have multiple "underlying" irqs. The gpio lines
	 * can be mapped to any one or none of these underlying irqs
	 * independently of each other. This driver sets up an irq domain and
	 * hands out separate irqs to each gpio line
	 */
	struct irq_domain *domain;

	/*
	 * This array contains information on each underlying irq, each
	 * irq of the grgpio core itself.
	 */
	struct grgpio_uirq uirqs[GRGPIO_MAX_NGPIO];

	/*
	 * This array contains information for each gpio line on the irqs
	 * obtains from this driver. An index value of -1 for a certain gpio
	 * line indicates that the line has no irq. Otherwise the index connects
	 * the irq to the underlying irq by pointing into the uirqs array.
	 */
	struct grgpio_lirq lirqs[GRGPIO_MAX_NGPIO];
};

static void grgpio_set_imask(struct grgpio_priv *priv, unsigned int offset,
			     int val)
{
	struct gpio_chip *gc = &priv->gc;

	if (val)
		priv->imask |= BIT(offset);
	else
		priv->imask &= ~BIT(offset);
	gc->write_reg(priv->regs + GRGPIO_IMASK, priv->imask);
}

static int grgpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
	struct grgpio_priv *priv = gpiochip_get_data(gc);

	if (offset >= gc->ngpio)
		return -ENXIO;

	if (priv->lirqs[offset].index < 0)
		return -ENXIO;

	return irq_create_mapping(priv->domain, offset);
}

/* -------------------- IRQ chip functions -------------------- */

static int grgpio_irq_set_type(struct irq_data *d, unsigned int type)
{
	struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
	unsigned long flags;
	u32 mask = BIT(d->hwirq);
	u32 ipol;
	u32 iedge;
	u32 pol;
	u32 edge;

	switch (type) {
	case IRQ_TYPE_LEVEL_LOW:
		pol = 0;
		edge = 0;
		break;
	case IRQ_TYPE_LEVEL_HIGH:
		pol = mask;
		edge = 0;
		break;
	case IRQ_TYPE_EDGE_FALLING:
		pol = 0;
		edge = mask;
		break;
	case IRQ_TYPE_EDGE_RISING:
		pol = mask;
		edge = mask;
		break;
	default:
		return -EINVAL;
	}

	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);

	ipol = priv->gc.read_reg(priv->regs + GRGPIO_IPOL) & ~mask;
	iedge = priv->gc.read_reg(priv->regs + GRGPIO_IEDGE) & ~mask;

	priv->gc.write_reg(priv->regs + GRGPIO_IPOL, ipol | pol);
	priv->gc.write_reg(priv->regs + GRGPIO_IEDGE, iedge | edge);

	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);

	return 0;
}

static void grgpio_irq_mask(struct irq_data *d)
{
	struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
	int offset = d->hwirq;
	unsigned long flags;

	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);

	grgpio_set_imask(priv, offset, 0);

	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
}

static void grgpio_irq_unmask(struct irq_data *d)
{
	struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
	int offset = d->hwirq;
	unsigned long flags;

	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);

	grgpio_set_imask(priv, offset, 1);

	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
}

static struct irq_chip grgpio_irq_chip = {
	.name			= "grgpio",
	.irq_mask		= grgpio_irq_mask,
	.irq_unmask		= grgpio_irq_unmask,
	.irq_set_type		= grgpio_irq_set_type,
};

static irqreturn_t grgpio_irq_handler(int irq, void *dev)
{
	struct grgpio_priv *priv = dev;
	int ngpio = priv->gc.ngpio;
	unsigned long flags;
	int i;
	int match = 0;

	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);

	/*
	 * For each gpio line, call its interrupt handler if it its underlying
	 * irq matches the current irq that is handled.
	 */
	for (i = 0; i < ngpio; i++) {
		struct grgpio_lirq *lirq = &priv->lirqs[i];

		if (priv->imask & BIT(i) && lirq->index >= 0 &&
		    priv->uirqs[lirq->index].uirq == irq) {
			generic_handle_irq(lirq->irq);
			match = 1;
		}
	}

	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);

	if (!match)
		dev_warn(priv->dev, "No gpio line matched irq %d\n", irq);

	return IRQ_HANDLED;
}

/*
 * This function will be called as a consequence of the call to
 * irq_create_mapping in grgpio_to_irq
 */
static int grgpio_irq_map(struct irq_domain *d, unsigned int irq,
			  irq_hw_number_t hwirq)
{
	struct grgpio_priv *priv = d->host_data;
	struct grgpio_lirq *lirq;
	struct grgpio_uirq *uirq;
	unsigned long flags;
	int offset = hwirq;
	int ret = 0;

	if (!priv)
		return -EINVAL;

	lirq = &priv->lirqs[offset];
	if (lirq->index < 0)
		return -EINVAL;

	dev_dbg(priv->dev, "Mapping irq %d for gpio line %d\n",
		irq, offset);

	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);

	/* Request underlying irq if not already requested */
	lirq->irq = irq;
	uirq = &priv->uirqs[lirq->index];
	if (uirq->refcnt == 0) {
		ret = request_irq(uirq->uirq, grgpio_irq_handler, 0,
				  dev_name(priv->dev), priv);
		if (ret) {
			dev_err(priv->dev,
				"Could not request underlying irq %d\n",
				uirq->uirq);

			spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);

			return ret;
		}
	}
	uirq->refcnt++;

	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);

	/* Setup irq  */
	irq_set_chip_data(irq, priv);
	irq_set_chip_and_handler(irq, &grgpio_irq_chip,
				 handle_simple_irq);
	irq_set_noprobe(irq);

	return ret;
}

static void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq)
{
	struct grgpio_priv *priv = d->host_data;
	int index;
	struct grgpio_lirq *lirq;
	struct grgpio_uirq *uirq;
	unsigned long flags;
	int ngpio = priv->gc.ngpio;
	int i;

	irq_set_chip_and_handler(irq, NULL, NULL);
	irq_set_chip_data(irq, NULL);

	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);

	/* Free underlying irq if last user unmapped */
	index = -1;
	for (i = 0; i < ngpio; i++) {
		lirq = &priv->lirqs[i];
		if (lirq->irq == irq) {
			grgpio_set_imask(priv, i, 0);
			lirq->irq = 0;
			index = lirq->index;
			break;
		}
	}
	WARN_ON(index < 0);

	if (index >= 0) {
		uirq = &priv->uirqs[lirq->index];
		uirq->refcnt--;
		if (uirq->refcnt == 0)
			free_irq(uirq->uirq, priv);
	}

	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
}

static const struct irq_domain_ops grgpio_irq_domain_ops = {
	.map	= grgpio_irq_map,
	.unmap	= grgpio_irq_unmap,
};

/* ------------------------------------------------------------ */

static int grgpio_probe(struct platform_device *ofdev)
{
	struct device_node *np = ofdev->dev.of_node;
	void  __iomem *regs;
	struct gpio_chip *gc;
	struct grgpio_priv *priv;
	struct resource *res;
	int err;
	u32 prop;
	s32 *irqmap;
	int size;
	int i;

	priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
	regs = devm_ioremap_resource(&ofdev->dev, res);
	if (IS_ERR(regs))
		return PTR_ERR(regs);

	gc = &priv->gc;
	err = bgpio_init(gc, &ofdev->dev, 4, regs + GRGPIO_DATA,
			 regs + GRGPIO_OUTPUT, NULL, regs + GRGPIO_DIR, NULL,
			 BGPIOF_BIG_ENDIAN_BYTE_ORDER);
	if (err) {
		dev_err(&ofdev->dev, "bgpio_init() failed\n");
		return err;
	}

	priv->regs = regs;
	priv->imask = gc->read_reg(regs + GRGPIO_IMASK);
	priv->dev = &ofdev->dev;

	gc->of_node = np;
	gc->owner = THIS_MODULE;
	gc->to_irq = grgpio_to_irq;
	gc->label = devm_kasprintf(&ofdev->dev, GFP_KERNEL, "%pOF", np);
	gc->base = -1;

	err = of_property_read_u32(np, "nbits", &prop);
	if (err || prop <= 0 || prop > GRGPIO_MAX_NGPIO) {
		gc->ngpio = GRGPIO_MAX_NGPIO;
		dev_dbg(&ofdev->dev,
			"No or invalid nbits property: assume %d\n", gc->ngpio);
	} else {
		gc->ngpio = prop;
	}

	/*
	 * The irqmap contains the index values indicating which underlying irq,
	 * if anyone, is connected to that line
	 */
	irqmap = (s32 *)of_get_property(np, "irqmap", &size);
	if (irqmap) {
		if (size < gc->ngpio) {
			dev_err(&ofdev->dev,
				"irqmap shorter than ngpio (%d < %d)\n",
				size, gc->ngpio);
			return -EINVAL;
		}

		priv->domain = irq_domain_add_linear(np, gc->ngpio,
						     &grgpio_irq_domain_ops,
						     priv);
		if (!priv->domain) {
			dev_err(&ofdev->dev, "Could not add irq domain\n");
			return -EINVAL;
		}

		for (i = 0; i < gc->ngpio; i++) {
			struct grgpio_lirq *lirq;
			int ret;

			lirq = &priv->lirqs[i];
			lirq->index = irqmap[i];

			if (lirq->index < 0)
				continue;

			ret = platform_get_irq(ofdev, lirq->index);
			if (ret <= 0) {
				/*
				 * Continue without irq functionality for that
				 * gpio line
				 */
				dev_err(priv->dev,
					"Failed to get irq for offset %d\n", i);
				continue;
			}
			priv->uirqs[lirq->index].uirq = ret;
		}
	}

	platform_set_drvdata(ofdev, priv);

	err = gpiochip_add_data(gc, priv);
	if (err) {
		dev_err(&ofdev->dev, "Could not add gpiochip\n");
		if (priv->domain)
			irq_domain_remove(priv->domain);
		return err;
	}

	dev_info(&ofdev->dev, "regs=0x%p, base=%d, ngpio=%d, irqs=%s\n",
		 priv->regs, gc->base, gc->ngpio, priv->domain ? "on" : "off");

	return 0;
}

static int grgpio_remove(struct platform_device *ofdev)
{
	struct grgpio_priv *priv = platform_get_drvdata(ofdev);
	unsigned long flags;
	int i;
	int ret = 0;

	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);

	if (priv->domain) {
		for (i = 0; i < GRGPIO_MAX_NGPIO; i++) {
			if (priv->uirqs[i].refcnt != 0) {
				ret = -EBUSY;
				goto out;
			}
		}
	}

	gpiochip_remove(&priv->gc);

	if (priv->domain)
		irq_domain_remove(priv->domain);

out:
	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);

	return ret;
}

static const struct of_device_id grgpio_match[] = {
	{.name = "GAISLER_GPIO"},
	{.name = "01_01a"},
	{},
};

MODULE_DEVICE_TABLE(of, grgpio_match);

static struct platform_driver grgpio_driver = {
	.driver = {
		.name = "grgpio",
		.of_match_table = grgpio_match,
	},
	.probe = grgpio_probe,
	.remove = grgpio_remove,
};
module_platform_driver(grgpio_driver);

MODULE_AUTHOR("Aeroflex Gaisler AB.");
MODULE_DESCRIPTION("Driver for Aeroflex Gaisler GRGPIO");
MODULE_LICENSE("GPL");
Commit	Line	Data
ddb27f3b AL	1	/*
	2	* Driver for Aeroflex Gaisler GRGPIO General Purpose I/O cores.
	3	*
	4	* 2013 (c) Aeroflex Gaisler AB
	5	*
	6	* This driver supports the GRGPIO GPIO core available in the GRLIB VHDL
	7	* IP core library.
	8	*
	9	* Full documentation of the GRGPIO core can be found here:
	10	* http://www.gaisler.com/products/grlib/grip.pdf
	11	*
	12	* See "Documentation/devicetree/bindings/gpio/gpio-grgpio.txt" for
	13	* information on open firmware properties.
	14	*
	15	* This program is free software; you can redistribute it and/or modify it
	16	* under the terms of the GNU General Public License as published by the
	17	* Free Software Foundation; either version 2 of the License, or (at your
	18	* option) any later version.
	19	*
	20	* Contributors: Andreas Larsson <[email protected]>
	21	*/
	22
	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
	25	#include <linux/init.h>
	26	#include <linux/spinlock.h>
	27	#include <linux/io.h>
	28	#include <linux/of.h>
ddb27f3b	29	#include <linux/of_platform.h>
00d712a9	30	#include <linux/gpio/driver.h>
ddb27f3b AL	31	#include <linux/slab.h>
ddb27f3b AL	32	#include <linux/err.h>
0f4630f3	33	#include <linux/gpio/driver.h>
08ffb222 AL	34	#include <linux/interrupt.h>
	35	#include <linux/irq.h>
	36	#include <linux/irqdomain.h>
5c7b0c4e	37	#include <linux/bitops.h>
ddb27f3b AL	38
	39	#define GRGPIO_MAX_NGPIO 32
	40
	41	#define GRGPIO_DATA 0x00
	42	#define GRGPIO_OUTPUT 0x04
	43	#define GRGPIO_DIR 0x08
	44	#define GRGPIO_IMASK 0x0c
	45	#define GRGPIO_IPOL 0x10
	46	#define GRGPIO_IEDGE 0x14
	47	#define GRGPIO_BYPASS 0x18
	48	#define GRGPIO_IMAP_BASE 0x20
	49
08ffb222 AL	50	/* Structure for an irq of the core - called an underlying irq */
	51	struct grgpio_uirq {
	52	u8 refcnt; /* Reference counter to manage requesting/freeing of uirq */
	53	u8 uirq; /* Underlying irq of the gpio driver */
	54	};
	55
	56	/*
	57	* Structure for an irq of a gpio line handed out by this driver. The index is
	58	* used to map to the corresponding underlying irq.
	59	*/
	60	struct grgpio_lirq {
	61	s8 index; /* Index into struct grgpio_priv's uirqs, or -1 */
	62	u8 irq; /* irq for the gpio line */
	63	};
	64
ddb27f3b	65	struct grgpio_priv {
0f4630f3	66	struct gpio_chip gc;
ddb27f3b AL	67	void __iomem *regs;
ddb27f3b AL	68	struct device *dev;
08ffb222 AL	69
	70	u32 imask; /* irq mask shadow register */
	71
	72	/*
	73	* The grgpio core can have multiple "underlying" irqs. The gpio lines
	74	* can be mapped to any one or none of these underlying irqs
	75	* independently of each other. This driver sets up an irq domain and
	76	* hands out separate irqs to each gpio line
	77	*/
	78	struct irq_domain *domain;
	79
	80	/*
	81	* This array contains information on each underlying irq, each
	82	* irq of the grgpio core itself.
	83	*/
	84	struct grgpio_uirq uirqs[GRGPIO_MAX_NGPIO];
	85
	86	/*
	87	* This array contains information for each gpio line on the irqs
	88	* obtains from this driver. An index value of -1 for a certain gpio
	89	* line indicates that the line has no irq. Otherwise the index connects
	90	* the irq to the underlying irq by pointing into the uirqs array.
	91	*/
	92	struct grgpio_lirq lirqs[GRGPIO_MAX_NGPIO];
ddb27f3b AL	93	};
ddb27f3b AL	94
08ffb222 AL	95	static void grgpio_set_imask(struct grgpio_priv *priv, unsigned int offset,
	96	int val)
	97	{
0f4630f3	98	struct gpio_chip *gc = &priv->gc;
08ffb222 AL	99
08ffb222 AL	100	if (val)
5c7b0c4e	101	priv->imask \|= BIT(offset);
08ffb222	102	else
5c7b0c4e	103	priv->imask &= ~BIT(offset);
0f4630f3	104	gc->write_reg(priv->regs + GRGPIO_IMASK, priv->imask);
08ffb222 AL	105	}
	106
	107	static int grgpio_to_irq(struct gpio_chip *gc, unsigned offset)
	108	{
0f4630f3	109	struct grgpio_priv *priv = gpiochip_get_data(gc);
08ffb222	110
d3c2155c	111	if (offset >= gc->ngpio)
08ffb222 AL	112	return -ENXIO;
	113
	114	if (priv->lirqs[offset].index < 0)
	115	return -ENXIO;
	116
	117	return irq_create_mapping(priv->domain, offset);
	118	}
	119
	120	/* -------------------- IRQ chip functions -------------------- */
	121
	122	static int grgpio_irq_set_type(struct irq_data *d, unsigned int type)
	123	{
	124	struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
	125	unsigned long flags;
	126	u32 mask = BIT(d->hwirq);
	127	u32 ipol;
	128	u32 iedge;
	129	u32 pol;
	130	u32 edge;
	131
	132	switch (type) {
	133	case IRQ_TYPE_LEVEL_LOW:
	134	pol = 0;
	135	edge = 0;
	136	break;
	137	case IRQ_TYPE_LEVEL_HIGH:
	138	pol = mask;
	139	edge = 0;
	140	break;
	141	case IRQ_TYPE_EDGE_FALLING:
	142	pol = 0;
	143	edge = mask;
	144	break;
	145	case IRQ_TYPE_EDGE_RISING:
	146	pol = mask;
	147	edge = mask;
	148	break;
	149	default:
	150	return -EINVAL;
	151	}
	152
0f4630f3	153	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
08ffb222	154
0f4630f3 LW	155	ipol = priv->gc.read_reg(priv->regs + GRGPIO_IPOL) & ~mask;
0f4630f3 LW	156	iedge = priv->gc.read_reg(priv->regs + GRGPIO_IEDGE) & ~mask;
08ffb222	157
0f4630f3 LW	158	priv->gc.write_reg(priv->regs + GRGPIO_IPOL, ipol \| pol);
0f4630f3 LW	159	priv->gc.write_reg(priv->regs + GRGPIO_IEDGE, iedge \| edge);
08ffb222	160
0f4630f3	161	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
08ffb222 AL	162
	163	return 0;
	164	}
	165
	166	static void grgpio_irq_mask(struct irq_data *d)
	167	{
	168	struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
	169	int offset = d->hwirq;
7fa25937 AC	170	unsigned long flags;
7fa25937 AC	171
0f4630f3	172	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
08ffb222 AL	173
08ffb222 AL	174	grgpio_set_imask(priv, offset, 0);
7fa25937	175
0f4630f3	176	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
08ffb222 AL	177	}
	178
	179	static void grgpio_irq_unmask(struct irq_data *d)
	180	{
	181	struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
	182	int offset = d->hwirq;
7fa25937 AC	183	unsigned long flags;
7fa25937 AC	184
0f4630f3	185	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
08ffb222 AL	186
08ffb222 AL	187	grgpio_set_imask(priv, offset, 1);
7fa25937	188
0f4630f3	189	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
08ffb222 AL	190	}
	191
	192	static struct irq_chip grgpio_irq_chip = {
	193	.name = "grgpio",
	194	.irq_mask = grgpio_irq_mask,
	195	.irq_unmask = grgpio_irq_unmask,
	196	.irq_set_type = grgpio_irq_set_type,
	197	};
	198
	199	static irqreturn_t grgpio_irq_handler(int irq, void *dev)
	200	{
	201	struct grgpio_priv *priv = dev;
0f4630f3	202	int ngpio = priv->gc.ngpio;
08ffb222 AL	203	unsigned long flags;
	204	int i;
	205	int match = 0;
	206
0f4630f3	207	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
08ffb222 AL	208
	209	/*
	210	* For each gpio line, call its interrupt handler if it its underlying
	211	* irq matches the current irq that is handled.
	212	*/
	213	for (i = 0; i < ngpio; i++) {
	214	struct grgpio_lirq *lirq = &priv->lirqs[i];
	215
	216	if (priv->imask & BIT(i) && lirq->index >= 0 &&
	217	priv->uirqs[lirq->index].uirq == irq) {
	218	generic_handle_irq(lirq->irq);
	219	match = 1;
	220	}
	221	}
	222
0f4630f3	223	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
08ffb222 AL	224
	225	if (!match)
	226	dev_warn(priv->dev, "No gpio line matched irq %d\n", irq);
	227
	228	return IRQ_HANDLED;
	229	}
	230
	231	/*
	232	* This function will be called as a consequence of the call to
	233	* irq_create_mapping in grgpio_to_irq
	234	*/
61e3884e SK	235	static int grgpio_irq_map(struct irq_domain *d, unsigned int irq,
61e3884e SK	236	irq_hw_number_t hwirq)
08ffb222 AL	237	{
	238	struct grgpio_priv *priv = d->host_data;
	239	struct grgpio_lirq *lirq;
	240	struct grgpio_uirq *uirq;
	241	unsigned long flags;
	242	int offset = hwirq;
	243	int ret = 0;
	244
	245	if (!priv)
	246	return -EINVAL;
	247
	248	lirq = &priv->lirqs[offset];
	249	if (lirq->index < 0)
	250	return -EINVAL;
	251
	252	dev_dbg(priv->dev, "Mapping irq %d for gpio line %d\n",
	253	irq, offset);
	254
0f4630f3	255	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
08ffb222 AL	256
	257	/* Request underlying irq if not already requested */
	258	lirq->irq = irq;
	259	uirq = &priv->uirqs[lirq->index];
	260	if (uirq->refcnt == 0) {
	261	ret = request_irq(uirq->uirq, grgpio_irq_handler, 0,
	262	dev_name(priv->dev), priv);
	263	if (ret) {
	264	dev_err(priv->dev,
	265	"Could not request underlying irq %d\n",
	266	uirq->uirq);
	267
0f4630f3	268	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
08ffb222 AL	269
	270	return ret;
	271	}
	272	}
	273	uirq->refcnt++;
	274
0f4630f3	275	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
08ffb222 AL	276
	277	/* Setup irq */
	278	irq_set_chip_data(irq, priv);
	279	irq_set_chip_and_handler(irq, &grgpio_irq_chip,
	280	handle_simple_irq);
08ffb222	281	irq_set_noprobe(irq);
08ffb222 AL	282
	283	return ret;
	284	}
	285
61e3884e	286	static void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq)
08ffb222 AL	287	{
	288	struct grgpio_priv *priv = d->host_data;
	289	int index;
	290	struct grgpio_lirq *lirq;
	291	struct grgpio_uirq *uirq;
	292	unsigned long flags;
0f4630f3	293	int ngpio = priv->gc.ngpio;
08ffb222 AL	294	int i;
08ffb222 AL	295
08ffb222 AL	296	irq_set_chip_and_handler(irq, NULL, NULL);
	297	irq_set_chip_data(irq, NULL);
	298
0f4630f3	299	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
08ffb222 AL	300
	301	/* Free underlying irq if last user unmapped */
	302	index = -1;
	303	for (i = 0; i < ngpio; i++) {
	304	lirq = &priv->lirqs[i];
	305	if (lirq->irq == irq) {
	306	grgpio_set_imask(priv, i, 0);
	307	lirq->irq = 0;
	308	index = lirq->index;
	309	break;
	310	}
	311	}
	312	WARN_ON(index < 0);
	313
	314	if (index >= 0) {
	315	uirq = &priv->uirqs[lirq->index];
	316	uirq->refcnt--;
	317	if (uirq->refcnt == 0)
	318	free_irq(uirq->uirq, priv);
	319	}
	320
0f4630f3	321	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
08ffb222 AL	322	}
08ffb222 AL	323
0b354dc4	324	static const struct irq_domain_ops grgpio_irq_domain_ops = {
08ffb222 AL	325	.map = grgpio_irq_map,
	326	.unmap = grgpio_irq_unmap,
	327	};
	328
	329	/* ------------------------------------------------------------ */
	330
ddb27f3b AL	331	static int grgpio_probe(struct platform_device *ofdev)
	332	{
	333	struct device_node *np = ofdev->dev.of_node;
	334	void __iomem *regs;
	335	struct gpio_chip *gc;
ddb27f3b AL	336	struct grgpio_priv *priv;
	337	struct resource *res;
	338	int err;
	339	u32 prop;
08ffb222 AL	340	s32 *irqmap;
	341	int size;
	342	int i;
ddb27f3b AL	343
	344	priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL);
	345	if (!priv)
	346	return -ENOMEM;
	347
	348	res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
	349	regs = devm_ioremap_resource(&ofdev->dev, res);
	350	if (IS_ERR(regs))
	351	return PTR_ERR(regs);
	352
0f4630f3 LW	353	gc = &priv->gc;
0f4630f3 LW	354	err = bgpio_init(gc, &ofdev->dev, 4, regs + GRGPIO_DATA,
ddb27f3b AL	355	regs + GRGPIO_OUTPUT, NULL, regs + GRGPIO_DIR, NULL,
	356	BGPIOF_BIG_ENDIAN_BYTE_ORDER);
	357	if (err) {
	358	dev_err(&ofdev->dev, "bgpio_init() failed\n");
	359	return err;
	360	}
	361
	362	priv->regs = regs;
0f4630f3	363	priv->imask = gc->read_reg(regs + GRGPIO_IMASK);
ddb27f3b AL	364	priv->dev = &ofdev->dev;
ddb27f3b AL	365
ddb27f3b AL	366	gc->of_node = np;
ddb27f3b AL	367	gc->owner = THIS_MODULE;
08ffb222	368	gc->to_irq = grgpio_to_irq;
7eb6ce2f	369	gc->label = devm_kasprintf(&ofdev->dev, GFP_KERNEL, "%pOF", np);
ddb27f3b AL	370	gc->base = -1;
	371
	372	err = of_property_read_u32(np, "nbits", &prop);
	373	if (err \|\| prop <= 0 \|\| prop > GRGPIO_MAX_NGPIO) {
	374	gc->ngpio = GRGPIO_MAX_NGPIO;
	375	dev_dbg(&ofdev->dev,
	376	"No or invalid nbits property: assume %d\n", gc->ngpio);
	377	} else {
	378	gc->ngpio = prop;
	379	}
	380
08ffb222 AL	381	/*
	382	* The irqmap contains the index values indicating which underlying irq,
	383	* if anyone, is connected to that line
	384	*/
	385	irqmap = (s32 *)of_get_property(np, "irqmap", &size);
	386	if (irqmap) {
	387	if (size < gc->ngpio) {
	388	dev_err(&ofdev->dev,
	389	"irqmap shorter than ngpio (%d < %d)\n",
	390	size, gc->ngpio);
	391	return -EINVAL;
	392	}
	393
	394	priv->domain = irq_domain_add_linear(np, gc->ngpio,
	395	&grgpio_irq_domain_ops,
	396	priv);
	397	if (!priv->domain) {
	398	dev_err(&ofdev->dev, "Could not add irq domain\n");
	399	return -EINVAL;
	400	}
	401
	402	for (i = 0; i < gc->ngpio; i++) {
	403	struct grgpio_lirq *lirq;
	404	int ret;
	405
	406	lirq = &priv->lirqs[i];
	407	lirq->index = irqmap[i];
	408
	409	if (lirq->index < 0)
	410	continue;
	411
	412	ret = platform_get_irq(ofdev, lirq->index);
	413	if (ret <= 0) {
	414	/*
	415	* Continue without irq functionality for that
	416	* gpio line
	417	*/
	418	dev_err(priv->dev,
	419	"Failed to get irq for offset %d\n", i);
	420	continue;
	421	}
	422	priv->uirqs[lirq->index].uirq = ret;
	423	}
	424	}
	425
ddb27f3b AL	426	platform_set_drvdata(ofdev, priv);
ddb27f3b AL	427
0f4630f3	428	err = gpiochip_add_data(gc, priv);
ddb27f3b AL	429	if (err) {
ddb27f3b AL	430	dev_err(&ofdev->dev, "Could not add gpiochip\n");
879828c6 AL	431	if (priv->domain)
879828c6 AL	432	irq_domain_remove(priv->domain);
ddb27f3b AL	433	return err;
	434	}
	435
08ffb222 AL	436	dev_info(&ofdev->dev, "regs=0x%p, base=%d, ngpio=%d, irqs=%s\n",
08ffb222 AL	437	priv->regs, gc->base, gc->ngpio, priv->domain ? "on" : "off");
ddb27f3b AL	438
	439	return 0;
	440	}
	441
	442	static int grgpio_remove(struct platform_device *ofdev)
	443	{
	444	struct grgpio_priv *priv = platform_get_drvdata(ofdev);
08ffb222 AL	445	unsigned long flags;
	446	int i;
	447	int ret = 0;
	448
0f4630f3	449	spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
08ffb222 AL	450
	451	if (priv->domain) {
	452	for (i = 0; i < GRGPIO_MAX_NGPIO; i++) {
	453	if (priv->uirqs[i].refcnt != 0) {
	454	ret = -EBUSY;
	455	goto out;
	456	}
	457	}
	458	}
	459
0f4630f3	460	gpiochip_remove(&priv->gc);
08ffb222 AL	461
	462	if (priv->domain)
	463	irq_domain_remove(priv->domain);
	464
	465	out:
0f4630f3	466	spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
ddb27f3b	467
08ffb222	468	return ret;
ddb27f3b AL	469	}
ddb27f3b AL	470
f77b6448	471	static const struct of_device_id grgpio_match[] = {
ddb27f3b AL	472	{.name = "GAISLER_GPIO"},
	473	{.name = "01_01a"},
	474	{},
	475	};
	476
	477	MODULE_DEVICE_TABLE(of, grgpio_match);
	478
	479	static struct platform_driver grgpio_driver = {
	480	.driver = {
	481	.name = "grgpio",
ddb27f3b AL	482	.of_match_table = grgpio_match,
	483	},
	484	.probe = grgpio_probe,
	485	.remove = grgpio_remove,
	486	};
	487	module_platform_driver(grgpio_driver);
	488
	489	MODULE_AUTHOR("Aeroflex Gaisler AB.");
	490	MODULE_DESCRIPTION("Driver for Aeroflex Gaisler GRGPIO");
	491	MODULE_LICENSE("GPL");