[mirror_ubuntu-bionic-kernel.git] / drivers / i2c / muxes / i2c-mux-pca954x.c

/*
 * I2C multiplexer
 *
 * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
 * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
 *
 * This module supports the PCA954x series of I2C multiplexer/switch chips
 * made by Philips Semiconductors.
 * This includes the:
 *	 PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547
 *	 and PCA9548.
 *
 * These chips are all controlled via the I2C bus itself, and all have a
 * single 8-bit register. The upstream "parent" bus fans out to two,
 * four, or eight downstream busses or channels; which of these
 * are selected is determined by the chip type and register contents. A
 * mux can select only one sub-bus at a time; a switch can select any
 * combination simultaneously.
 *
 * Based on:
 *	pca954x.c from Kumar Gala <galak@kernel.crashing.org>
 * Copyright (C) 2006
 *
 * Based on:
 *	pca954x.c from Ken Harrenstien
 * Copyright (C) 2004 Google, Inc. (Ken Harrenstien)
 *
 * Based on:
 *	i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
 * and
 *	pca9540.c from Jean Delvare <jdelvare@suse.de>.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/i2c-mux.h>
#include <linux/i2c/pca954x.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#define PCA954X_MAX_NCHANS 8

#define PCA954X_IRQ_OFFSET 4

enum pca_type {
	pca_9540,
	pca_9542,
	pca_9543,
	pca_9544,
	pca_9545,
	pca_9546,
	pca_9547,
	pca_9548,
};

struct chip_desc {
	u8 nchans;
	u8 enable;	/* used for muxes only */
	u8 has_irq;
	enum muxtype {
		pca954x_ismux = 0,
		pca954x_isswi
	} muxtype;
};

struct pca954x {
	const struct chip_desc *chip;

	u8 last_chan;		/* last register value */
	u8 deselect;
	struct i2c_client *client;

	struct irq_domain *irq;
	unsigned int irq_mask;
	raw_spinlock_t lock;
};

/* Provide specs for the PCA954x types we know about */
static const struct chip_desc chips[] = {
	[pca_9540] = {
		.nchans = 2,
		.enable = 0x4,
		.muxtype = pca954x_ismux,
	},
	[pca_9542] = {
		.nchans = 2,
		.enable = 0x4,
		.has_irq = 1,
		.muxtype = pca954x_ismux,
	},
	[pca_9543] = {
		.nchans = 2,
		.has_irq = 1,
		.muxtype = pca954x_isswi,
	},
	[pca_9544] = {
		.nchans = 4,
		.enable = 0x4,
		.has_irq = 1,
		.muxtype = pca954x_ismux,
	},
	[pca_9545] = {
		.nchans = 4,
		.has_irq = 1,
		.muxtype = pca954x_isswi,
	},
	[pca_9546] = {
		.nchans = 4,
		.muxtype = pca954x_isswi,
	},
	[pca_9547] = {
		.nchans = 8,
		.enable = 0x8,
		.muxtype = pca954x_ismux,
	},
	[pca_9548] = {
		.nchans = 8,
		.muxtype = pca954x_isswi,
	},
};

static const struct i2c_device_id pca954x_id[] = {
	{ "pca9540", pca_9540 },
	{ "pca9542", pca_9542 },
	{ "pca9543", pca_9543 },
	{ "pca9544", pca_9544 },
	{ "pca9545", pca_9545 },
	{ "pca9546", pca_9546 },
	{ "pca9547", pca_9547 },
	{ "pca9548", pca_9548 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pca954x_id);

#ifdef CONFIG_OF
static const struct of_device_id pca954x_of_match[] = {
	{ .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
	{ .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
	{ .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
	{ .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
	{ .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
	{ .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
	{ .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
	{ .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
	{}
};
MODULE_DEVICE_TABLE(of, pca954x_of_match);
#endif

/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
   for this as they will try to lock adapter a second time */
static int pca954x_reg_write(struct i2c_adapter *adap,
			     struct i2c_client *client, u8 val)
{
	int ret = -ENODEV;

	if (adap->algo->master_xfer) {
		struct i2c_msg msg;
		char buf[1];

		msg.addr = client->addr;
		msg.flags = 0;
		msg.len = 1;
		buf[0] = val;
		msg.buf = buf;
		ret = __i2c_transfer(adap, &msg, 1);

		if (ret >= 0 && ret != 1)
			ret = -EREMOTEIO;
	} else {
		union i2c_smbus_data data;
		ret = adap->algo->smbus_xfer(adap, client->addr,
					     client->flags,
					     I2C_SMBUS_WRITE,
					     val, I2C_SMBUS_BYTE, &data);
	}

	return ret;
}

static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
{
	struct pca954x *data = i2c_mux_priv(muxc);
	struct i2c_client *client = data->client;
	const struct chip_desc *chip = data->chip;
	u8 regval;
	int ret = 0;

	/* we make switches look like muxes, not sure how to be smarter */
	if (chip->muxtype == pca954x_ismux)
		regval = chan | chip->enable;
	else
		regval = 1 << chan;

	/* Only select the channel if its different from the last channel */
	if (data->last_chan != regval) {
		ret = pca954x_reg_write(muxc->parent, client, regval);
		data->last_chan = ret < 0 ? 0 : regval;
	}

	return ret;
}

static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
{
	struct pca954x *data = i2c_mux_priv(muxc);
	struct i2c_client *client = data->client;

	if (!(data->deselect & (1 << chan)))
		return 0;

	/* Deselect active channel */
	data->last_chan = 0;
	return pca954x_reg_write(muxc->parent, client, data->last_chan);
}

static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
{
	struct pca954x *data = dev_id;
	unsigned int child_irq;
	int ret, i, handled = 0;

	ret = i2c_smbus_read_byte(data->client);
	if (ret < 0)
		return IRQ_NONE;

	for (i = 0; i < data->chip->nchans; i++) {
		if (ret & BIT(PCA954X_IRQ_OFFSET + i)) {
			child_irq = irq_linear_revmap(data->irq, i);
			handle_nested_irq(child_irq);
			handled++;
		}
	}
	return handled ? IRQ_HANDLED : IRQ_NONE;
}

static void pca954x_irq_mask(struct irq_data *idata)
{
	struct pca954x *data = irq_data_get_irq_chip_data(idata);
	unsigned int pos = idata->hwirq;
	unsigned long flags;

	raw_spin_lock_irqsave(&data->lock, flags);

	data->irq_mask &= ~BIT(pos);
	if (!data->irq_mask)
		disable_irq(data->client->irq);

	raw_spin_unlock_irqrestore(&data->lock, flags);
}

static void pca954x_irq_unmask(struct irq_data *idata)
{
	struct pca954x *data = irq_data_get_irq_chip_data(idata);
	unsigned int pos = idata->hwirq;
	unsigned long flags;

	raw_spin_lock_irqsave(&data->lock, flags);

	if (!data->irq_mask)
		enable_irq(data->client->irq);
	data->irq_mask |= BIT(pos);

	raw_spin_unlock_irqrestore(&data->lock, flags);
}

static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
{
	if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW)
		return -EINVAL;
	return 0;
}

static struct irq_chip pca954x_irq_chip = {
	.name = "i2c-mux-pca954x",
	.irq_mask = pca954x_irq_mask,
	.irq_unmask = pca954x_irq_unmask,
	.irq_set_type = pca954x_irq_set_type,
};

static int pca954x_irq_setup(struct i2c_mux_core *muxc)
{
	struct pca954x *data = i2c_mux_priv(muxc);
	struct i2c_client *client = data->client;
	int c, err, irq;

	if (!data->chip->has_irq || client->irq <= 0)
		return 0;

	raw_spin_lock_init(&data->lock);

	data->irq = irq_domain_add_linear(client->dev.of_node,
					  data->chip->nchans,
					  &irq_domain_simple_ops, data);
	if (!data->irq)
		return -ENODEV;

	for (c = 0; c < data->chip->nchans; c++) {
		irq = irq_create_mapping(data->irq, c);
		irq_set_chip_data(irq, data);
		irq_set_chip_and_handler(irq, &pca954x_irq_chip,
			handle_simple_irq);
	}

	err = devm_request_threaded_irq(&client->dev, data->client->irq, NULL,
					pca954x_irq_handler,
					IRQF_ONESHOT | IRQF_SHARED,
					"pca954x", data);
	if (err)
		goto err_req_irq;

	disable_irq(data->client->irq);

	return 0;
err_req_irq:
	for (c = 0; c < data->chip->nchans; c++) {
		irq = irq_find_mapping(data->irq, c);
		irq_dispose_mapping(irq);
	}
	irq_domain_remove(data->irq);

	return err;
}

/*
 * I2C init/probing/exit functions
 */
static int pca954x_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
	struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
	struct device_node *of_node = client->dev.of_node;
	bool idle_disconnect_dt;
	struct gpio_desc *gpio;
	int num, force, class;
	struct i2c_mux_core *muxc;
	struct pca954x *data;
	const struct of_device_id *match;
	int ret;

	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
		return -ENODEV;

	muxc = i2c_mux_alloc(adap, &client->dev,
			     PCA954X_MAX_NCHANS, sizeof(*data), 0,
			     pca954x_select_chan, pca954x_deselect_mux);
	if (!muxc)
		return -ENOMEM;
	data = i2c_mux_priv(muxc);

	i2c_set_clientdata(client, muxc);
	data->client = client;

	/* Get the mux out of reset if a reset GPIO is specified. */
	gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
	if (IS_ERR(gpio))
		return PTR_ERR(gpio);

	/* Write the mux register at addr to verify
	 * that the mux is in fact present. This also
	 * initializes the mux to disconnected state.
	 */
	if (i2c_smbus_write_byte(client, 0) < 0) {
		dev_warn(&client->dev, "probe failed\n");
		return -ENODEV;
	}

	match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
	if (match)
		data->chip = of_device_get_match_data(&client->dev);
	else
		data->chip = &chips[id->driver_data];

	data->last_chan = 0;		   /* force the first selection */

	idle_disconnect_dt = of_node &&
		of_property_read_bool(of_node, "i2c-mux-idle-disconnect");

	ret = pca954x_irq_setup(muxc);
	if (ret)
		goto fail_del_adapters;

	/* Now create an adapter for each channel */
	for (num = 0; num < data->chip->nchans; num++) {
		bool idle_disconnect_pd = false;

		force = 0;			  /* dynamic adap number */
		class = 0;			  /* no class by default */
		if (pdata) {
			if (num < pdata->num_modes) {
				/* force static number */
				force = pdata->modes[num].adap_id;
				class = pdata->modes[num].class;
			} else
				/* discard unconfigured channels */
				break;
			idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
		}
		data->deselect |= (idle_disconnect_pd ||
				   idle_disconnect_dt) << num;

		ret = i2c_mux_add_adapter(muxc, force, num, class);
		if (ret)
			goto fail_del_adapters;
	}

	dev_info(&client->dev,
		 "registered %d multiplexed busses for I2C %s %s\n",
		 num, data->chip->muxtype == pca954x_ismux
				? "mux" : "switch", client->name);

	return 0;

fail_del_adapters:
	i2c_mux_del_adapters(muxc);
	return ret;
}

static int pca954x_remove(struct i2c_client *client)
{
	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
	struct pca954x *data = i2c_mux_priv(muxc);
	int c, irq;

	if (data->irq) {
		for (c = 0; c < data->chip->nchans; c++) {
			irq = irq_find_mapping(data->irq, c);
			irq_dispose_mapping(irq);
		}
		irq_domain_remove(data->irq);
	}

	i2c_mux_del_adapters(muxc);
	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int pca954x_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
	struct pca954x *data = i2c_mux_priv(muxc);

	data->last_chan = 0;
	return i2c_smbus_write_byte(client, 0);
}
#endif

static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);

static struct i2c_driver pca954x_driver = {
	.driver		= {
		.name	= "pca954x",
		.pm	= &pca954x_pm,
		.of_match_table = of_match_ptr(pca954x_of_match),
	},
	.probe		= pca954x_probe,
	.remove		= pca954x_remove,
	.id_table	= pca954x_id,
};

module_i2c_driver(pca954x_driver);

MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
7f528135 ML	1	/*
	2	* I2C multiplexer
	3	*
	4	* Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
	5	* Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
	6	*
	7	* This module supports the PCA954x series of I2C multiplexer/switch chips
	8	* made by Philips Semiconductors.
	9	* This includes the:
	10	* PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547
	11	* and PCA9548.
	12	*
	13	* These chips are all controlled via the I2C bus itself, and all have a
	14	* single 8-bit register. The upstream "parent" bus fans out to two,
	15	* four, or eight downstream busses or channels; which of these
	16	* are selected is determined by the chip type and register contents. A
	17	* mux can select only one sub-bus at a time; a switch can select any
	18	* combination simultaneously.
	19	*
	20	* Based on:
	21	* pca954x.c from Kumar Gala <galak@kernel.crashing.org>
	22	* Copyright (C) 2006
	23	*
	24	* Based on:
	25	* pca954x.c from Ken Harrenstien
	26	* Copyright (C) 2004 Google, Inc. (Ken Harrenstien)
	27	*
	28	* Based on:
	29	* i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
	30	* and
7c81c60f	31	* pca9540.c from Jean Delvare <jdelvare@suse.de>.
7f528135 ML	32	*
	33	* This file is licensed under the terms of the GNU General Public
	34	* License version 2. This program is licensed "as is" without any
	35	* warranty of any kind, whether express or implied.
	36	*/
	37
7f528135	38	#include <linux/device.h>
642653d1	39	#include <linux/gpio/consumer.h>
7f528135 ML	40	#include <linux/i2c.h>
7f528135 ML	41	#include <linux/i2c-mux.h>
7f528135	42	#include <linux/i2c/pca954x.h>
f2114795 PR	43	#include <linux/interrupt.h>
f2114795 PR	44	#include <linux/irq.h>
4b9b0073	45	#include <linux/module.h>
72f02715	46	#include <linux/of.h>
8a191a7a	47	#include <linux/of_device.h>
f2114795	48	#include <linux/of_irq.h>
f5e596cd	49	#include <linux/pm.h>
4b9b0073	50	#include <linux/slab.h>
f2114795	51	#include <linux/spinlock.h>
7f528135 ML	52
	53	#define PCA954X_MAX_NCHANS 8
	54
f2114795 PR	55	#define PCA954X_IRQ_OFFSET 4
f2114795 PR	56
7f528135 ML	57	enum pca_type {
	58	pca_9540,
	59	pca_9542,
	60	pca_9543,
	61	pca_9544,
	62	pca_9545,
	63	pca_9546,
	64	pca_9547,
	65	pca_9548,
	66	};
	67
7f528135 ML	68	struct chip_desc {
	69	u8 nchans;
	70	u8 enable; /* used for muxes only */
f2114795	71	u8 has_irq;
7f528135 ML	72	enum muxtype {
	73	pca954x_ismux = 0,
	74	pca954x_isswi
	75	} muxtype;
	76	};
	77
8a191a7a PR	78	struct pca954x {
	79	const struct chip_desc *chip;
	80
	81	u8 last_chan; /* last register value */
	82	u8 deselect;
	83	struct i2c_client *client;
f2114795 PR	84
	85	struct irq_domain *irq;
	86	unsigned int irq_mask;
743cc375	87	raw_spinlock_t lock;
8a191a7a PR	88	};
8a191a7a PR	89
7f528135 ML	90	/* Provide specs for the PCA954x types we know about */
	91	static const struct chip_desc chips[] = {
	92	[pca_9540] = {
	93	.nchans = 2,
	94	.enable = 0x4,
	95	.muxtype = pca954x_ismux,
	96	},
f8251f1d PR	97	[pca_9542] = {
	98	.nchans = 2,
	99	.enable = 0x4,
f2114795	100	.has_irq = 1,
f8251f1d PR	101	.muxtype = pca954x_ismux,
f8251f1d PR	102	},
7f528135 ML	103	[pca_9543] = {
7f528135 ML	104	.nchans = 2,
f2114795	105	.has_irq = 1,
7f528135 ML	106	.muxtype = pca954x_isswi,
	107	},
	108	[pca_9544] = {
	109	.nchans = 4,
	110	.enable = 0x4,
f2114795	111	.has_irq = 1,
7f528135 ML	112	.muxtype = pca954x_ismux,
	113	},
	114	[pca_9545] = {
	115	.nchans = 4,
f2114795	116	.has_irq = 1,
7f528135 ML	117	.muxtype = pca954x_isswi,
7f528135 ML	118	},
dbe4d69d ML	119	[pca_9546] = {
	120	.nchans = 4,
	121	.muxtype = pca954x_isswi,
	122	},
7f528135 ML	123	[pca_9547] = {
	124	.nchans = 8,
	125	.enable = 0x8,
	126	.muxtype = pca954x_ismux,
	127	},
	128	[pca_9548] = {
	129	.nchans = 8,
	130	.muxtype = pca954x_isswi,
	131	},
	132	};
	133
	134	static const struct i2c_device_id pca954x_id[] = {
	135	{ "pca9540", pca_9540 },
f8251f1d	136	{ "pca9542", pca_9542 },
7f528135 ML	137	{ "pca9543", pca_9543 },
	138	{ "pca9544", pca_9544 },
	139	{ "pca9545", pca_9545 },
dbe4d69d	140	{ "pca9546", pca_9546 },
7f528135 ML	141	{ "pca9547", pca_9547 },
	142	{ "pca9548", pca_9548 },
	143	{ }
	144	};
	145	MODULE_DEVICE_TABLE(i2c, pca954x_id);
	146
8a191a7a PR	147	#ifdef CONFIG_OF
	148	static const struct of_device_id pca954x_of_match[] = {
	149	{ .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
	150	{ .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
	151	{ .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
	152	{ .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
	153	{ .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
	154	{ .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
	155	{ .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
	156	{ .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
	157	{}
	158	};
acf6ef1d	159	MODULE_DEVICE_TABLE(of, pca954x_of_match);
8a191a7a PR	160	#endif
8a191a7a PR	161
7f528135 ML	162	/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
	163	for this as they will try to lock adapter a second time */
	164	static int pca954x_reg_write(struct i2c_adapter *adap,
	165	struct i2c_client *client, u8 val)
	166	{
	167	int ret = -ENODEV;
	168
	169	if (adap->algo->master_xfer) {
	170	struct i2c_msg msg;
	171	char buf[1];
	172
	173	msg.addr = client->addr;
	174	msg.flags = 0;
	175	msg.len = 1;
	176	buf[0] = val;
	177	msg.buf = buf;
0a8237ae	178	ret = __i2c_transfer(adap, &msg, 1);
7f638c1c RK	179
	180	if (ret >= 0 && ret != 1)
	181	ret = -EREMOTEIO;
7f528135 ML	182	} else {
	183	union i2c_smbus_data data;
	184	ret = adap->algo->smbus_xfer(adap, client->addr,
	185	client->flags,
	186	I2C_SMBUS_WRITE,
	187	val, I2C_SMBUS_BYTE, &data);
	188	}
	189
	190	return ret;
	191	}
	192
7fcac980	193	static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
7f528135	194	{
7fcac980 PR	195	struct pca954x *data = i2c_mux_priv(muxc);
7fcac980 PR	196	struct i2c_client *client = data->client;
8a191a7a	197	const struct chip_desc *chip = data->chip;
7f528135 ML	198	u8 regval;
	199	int ret = 0;
	200
	201	/* we make switches look like muxes, not sure how to be smarter */
	202	if (chip->muxtype == pca954x_ismux)
	203	regval = chan \| chip->enable;
	204	else
	205	regval = 1 << chan;
	206
	207	/* Only select the channel if its different from the last channel */
	208	if (data->last_chan != regval) {
7fcac980	209	ret = pca954x_reg_write(muxc->parent, client, regval);
7f638c1c	210	data->last_chan = ret < 0 ? 0 : regval;
7f528135 ML	211	}
	212
	213	return ret;
	214	}
	215
7fcac980	216	static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
7f528135	217	{
7fcac980 PR	218	struct pca954x *data = i2c_mux_priv(muxc);
	219	struct i2c_client *client = data->client;
	220
	221	if (!(data->deselect & (1 << chan)))
	222	return 0;
7f528135 ML	223
	224	/* Deselect active channel */
	225	data->last_chan = 0;
7fcac980	226	return pca954x_reg_write(muxc->parent, client, data->last_chan);
7f528135 ML	227	}
7f528135 ML	228
f2114795 PR	229	static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
	230	{
	231	struct pca954x *data = dev_id;
	232	unsigned int child_irq;
	233	int ret, i, handled = 0;
	234
	235	ret = i2c_smbus_read_byte(data->client);
	236	if (ret < 0)
	237	return IRQ_NONE;
	238
	239	for (i = 0; i < data->chip->nchans; i++) {
	240	if (ret & BIT(PCA954X_IRQ_OFFSET + i)) {
	241	child_irq = irq_linear_revmap(data->irq, i);
	242	handle_nested_irq(child_irq);
	243	handled++;
	244	}
	245	}
	246	return handled ? IRQ_HANDLED : IRQ_NONE;
	247	}
	248
	249	static void pca954x_irq_mask(struct irq_data *idata)
	250	{
	251	struct pca954x *data = irq_data_get_irq_chip_data(idata);
	252	unsigned int pos = idata->hwirq;
	253	unsigned long flags;
	254
743cc375	255	raw_spin_lock_irqsave(&data->lock, flags);
f2114795 PR	256
	257	data->irq_mask &= ~BIT(pos);
	258	if (!data->irq_mask)
	259	disable_irq(data->client->irq);
	260
743cc375	261	raw_spin_unlock_irqrestore(&data->lock, flags);
f2114795 PR	262	}
	263
	264	static void pca954x_irq_unmask(struct irq_data *idata)
	265	{
	266	struct pca954x *data = irq_data_get_irq_chip_data(idata);
	267	unsigned int pos = idata->hwirq;
	268	unsigned long flags;
	269
743cc375	270	raw_spin_lock_irqsave(&data->lock, flags);
f2114795 PR	271
	272	if (!data->irq_mask)
	273	enable_irq(data->client->irq);
	274	data->irq_mask \|= BIT(pos);
	275
743cc375	276	raw_spin_unlock_irqrestore(&data->lock, flags);
f2114795 PR	277	}
	278
	279	static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
	280	{
	281	if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW)
	282	return -EINVAL;
	283	return 0;
	284	}
	285
	286	static struct irq_chip pca954x_irq_chip = {
	287	.name = "i2c-mux-pca954x",
	288	.irq_mask = pca954x_irq_mask,
	289	.irq_unmask = pca954x_irq_unmask,
	290	.irq_set_type = pca954x_irq_set_type,
	291	};
	292
	293	static int pca954x_irq_setup(struct i2c_mux_core *muxc)
	294	{
	295	struct pca954x *data = i2c_mux_priv(muxc);
	296	struct i2c_client *client = data->client;
	297	int c, err, irq;
	298
	299	if (!data->chip->has_irq \|\| client->irq <= 0)
	300	return 0;
	301
743cc375	302	raw_spin_lock_init(&data->lock);
f2114795 PR	303
	304	data->irq = irq_domain_add_linear(client->dev.of_node,
	305	data->chip->nchans,
	306	&irq_domain_simple_ops, data);
	307	if (!data->irq)
	308	return -ENODEV;
	309
	310	for (c = 0; c < data->chip->nchans; c++) {
	311	irq = irq_create_mapping(data->irq, c);
	312	irq_set_chip_data(irq, data);
	313	irq_set_chip_and_handler(irq, &pca954x_irq_chip,
	314	handle_simple_irq);
	315	}
	316
	317	err = devm_request_threaded_irq(&client->dev, data->client->irq, NULL,
	318	pca954x_irq_handler,
	319	IRQF_ONESHOT \| IRQF_SHARED,
	320	"pca954x", data);
	321	if (err)
	322	goto err_req_irq;
	323
	324	disable_irq(data->client->irq);
	325
	326	return 0;
	327	err_req_irq:
	328	for (c = 0; c < data->chip->nchans; c++) {
	329	irq = irq_find_mapping(data->irq, c);
	330	irq_dispose_mapping(irq);
	331	}
	332	irq_domain_remove(data->irq);
	333
	334	return err;
	335	}
	336
7f528135 ML	337	/*
	338	* I2C init/probing/exit functions
	339	*/
db79f2a1 GR	340	static int pca954x_probe(struct i2c_client *client,
db79f2a1 GR	341	const struct i2c_device_id *id)
7f528135 ML	342	{
7f528135 ML	343	struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
6d4028c6	344	struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
72f02715 AS	345	struct device_node *of_node = client->dev.of_node;
72f02715 AS	346	bool idle_disconnect_dt;
4807e845	347	struct gpio_desc *gpio;
eee543e8	348	int num, force, class;
7fcac980	349	struct i2c_mux_core *muxc;
7f528135	350	struct pca954x *data;
8a191a7a	351	const struct of_device_id *match;
bc12cfc8	352	int ret;
7f528135 ML	353
7f528135 ML	354	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
bc12cfc8	355	return -ENODEV;
7f528135	356
7fcac980 PR	357	muxc = i2c_mux_alloc(adap, &client->dev,
	358	PCA954X_MAX_NCHANS, sizeof(*data), 0,
	359	pca954x_select_chan, pca954x_deselect_mux);
	360	if (!muxc)
bc12cfc8	361	return -ENOMEM;
7fcac980	362	data = i2c_mux_priv(muxc);
7f528135	363
7fcac980 PR	364	i2c_set_clientdata(client, muxc);
7fcac980 PR	365	data->client = client;
7f528135	366
4807e845	367	/* Get the mux out of reset if a reset GPIO is specified. */
58b59e0f UKK	368	gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
	369	if (IS_ERR(gpio))
	370	return PTR_ERR(gpio);
12097957	371
cd823db8 PG	372	/* Write the mux register at addr to verify
	373	* that the mux is in fact present. This also
	374	* initializes the mux to disconnected state.
7f528135	375	*/
cd823db8	376	if (i2c_smbus_write_byte(client, 0) < 0) {
7f528135	377	dev_warn(&client->dev, "probe failed\n");
bc12cfc8	378	return -ENODEV;
7f528135 ML	379	}
7f528135 ML	380
8a191a7a PR	381	match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
	382	if (match)
	383	data->chip = of_device_get_match_data(&client->dev);
e88162f9	384	else
8a191a7a PR	385	data->chip = &chips[id->driver_data];
8a191a7a PR	386
7f528135 ML	387	data->last_chan = 0; /* force the first selection */
7f528135 ML	388
72f02715 AS	389	idle_disconnect_dt = of_node &&
	390	of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
	391
f2114795 PR	392	ret = pca954x_irq_setup(muxc);
	393	if (ret)
	394	goto fail_del_adapters;
	395
7f528135	396	/* Now create an adapter for each channel */
8a191a7a	397	for (num = 0; num < data->chip->nchans; num++) {
72f02715 AS	398	bool idle_disconnect_pd = false;
72f02715 AS	399
7f528135	400	force = 0; /* dynamic adap number */
eee543e8	401	class = 0; /* no class by default */
7f528135	402	if (pdata) {
eee543e8	403	if (num < pdata->num_modes) {
7f528135 ML	404	/* force static number */
7f528135 ML	405	force = pdata->modes[num].adap_id;
eee543e8 JD	406	class = pdata->modes[num].class;
eee543e8 JD	407	} else
7f528135 ML	408	/* discard unconfigured channels */
7f528135 ML	409	break;
72f02715	410	idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
7f528135	411	}
ad092de6 AH	412	data->deselect \|= (idle_disconnect_pd \|\|
ad092de6 AH	413	idle_disconnect_dt) << num;
7f528135	414
7fcac980	415	ret = i2c_mux_add_adapter(muxc, force, num, class);
0756ac32	416	if (ret)
f2114795	417	goto fail_del_adapters;
7f528135 ML	418	}
	419
	420	dev_info(&client->dev,
	421	"registered %d multiplexed busses for I2C %s %s\n",
8a191a7a	422	num, data->chip->muxtype == pca954x_ismux
7f528135 ML	423	? "mux" : "switch", client->name);
	424
	425	return 0;
	426
f2114795	427	fail_del_adapters:
7fcac980	428	i2c_mux_del_adapters(muxc);
7f528135 ML	429	return ret;
	430	}
	431
db79f2a1	432	static int pca954x_remove(struct i2c_client *client)
7f528135	433	{
7fcac980	434	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
f2114795 PR	435	struct pca954x *data = i2c_mux_priv(muxc);
	436	int c, irq;
	437
	438	if (data->irq) {
	439	for (c = 0; c < data->chip->nchans; c++) {
	440	irq = irq_find_mapping(data->irq, c);
	441	irq_dispose_mapping(irq);
	442	}
	443	irq_domain_remove(data->irq);
	444	}
7f528135	445
7fcac980	446	i2c_mux_del_adapters(muxc);
7f528135 ML	447	return 0;
	448	}
	449
f5e596cd JZ	450	#ifdef CONFIG_PM_SLEEP
	451	static int pca954x_resume(struct device *dev)
	452	{
	453	struct i2c_client *client = to_i2c_client(dev);
7fcac980 PR	454	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
7fcac980 PR	455	struct pca954x *data = i2c_mux_priv(muxc);
f5e596cd JZ	456
	457	data->last_chan = 0;
	458	return i2c_smbus_write_byte(client, 0);
	459	}
	460	#endif
	461
	462	static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
	463
7f528135 ML	464	static struct i2c_driver pca954x_driver = {
	465	.driver = {
	466	.name = "pca954x",
f5e596cd	467	.pm = &pca954x_pm,
8a191a7a	468	.of_match_table = of_match_ptr(pca954x_of_match),
7f528135 ML	469	},
7f528135 ML	470	.probe = pca954x_probe,
db79f2a1	471	.remove = pca954x_remove,
7f528135 ML	472	.id_table = pca954x_id,
	473	};
	474
de05497a	475	module_i2c_driver(pca954x_driver);
7f528135 ML	476
	477	MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
	478	MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
	479	MODULE_LICENSE("GPL v2");