[net-next-2.6.git] / drivers / gpio / sx150x.c

/* Copyright (c) 2010, Code Aurora Forum. 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 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/i2c/sx150x.h>

struct sx150x_device_data {
	u8 reg_pullup;
	u8 reg_pulldn;
	u8 reg_drain;
	u8 reg_polarity;
	u8 reg_dir;
	u8 reg_data;
	u8 reg_irq_mask;
	u8 reg_irq_src;
	u8 reg_sense;
	u8 reg_clock;
	u8 reg_misc;
	u8 reg_reset;
	u8 ngpios;
};

struct sx150x_chip {
	struct gpio_chip                 gpio_chip;
	struct i2c_client               *client;
	const struct sx150x_device_data *dev_cfg;
	int                              irq_summary;
	int                              irq_base;
	u32                              irq_sense;
	unsigned long                    irq_set_type_pending;
	struct irq_chip                  irq_chip;
	struct mutex                     lock;
};

static const struct sx150x_device_data sx150x_devices[] = {
	[0] = { /* sx1508q */
		.reg_pullup   = 0x03,
		.reg_pulldn   = 0x04,
		.reg_drain    = 0x05,
		.reg_polarity = 0x06,
		.reg_dir      = 0x07,
		.reg_data     = 0x08,
		.reg_irq_mask = 0x09,
		.reg_irq_src  = 0x0c,
		.reg_sense    = 0x0b,
		.reg_clock    = 0x0f,
		.reg_misc     = 0x10,
		.reg_reset    = 0x7d,
		.ngpios       = 8
	},
	[1] = { /* sx1509q */
		.reg_pullup   = 0x07,
		.reg_pulldn   = 0x09,
		.reg_drain    = 0x0b,
		.reg_polarity = 0x0d,
		.reg_dir      = 0x0f,
		.reg_data     = 0x11,
		.reg_irq_mask = 0x13,
		.reg_irq_src  = 0x19,
		.reg_sense    = 0x17,
		.reg_clock    = 0x1e,
		.reg_misc     = 0x1f,
		.reg_reset    = 0x7d,
		.ngpios       = 16
	},
};

static const struct i2c_device_id sx150x_id[] = {
	{"sx1508q", 0},
	{"sx1509q", 1},
	{}
};
MODULE_DEVICE_TABLE(i2c, sx150x_id);

static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
{
	s32 err = i2c_smbus_write_byte_data(client, reg, val);

	if (err < 0)
		dev_warn(&client->dev,
			"i2c write fail: can't write %02x to %02x: %d\n",
			val, reg, err);
	return err;
}

static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
{
	s32 err = i2c_smbus_read_byte_data(client, reg);

	if (err >= 0)
		*val = err;
	else
		dev_warn(&client->dev,
			"i2c read fail: can't read from %02x: %d\n",
			reg, err);
	return err;
}

static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
{
	return (chip->dev_cfg->ngpios == offset);
}

/*
 * These utility functions solve the common problem of locating and setting
 * configuration bits.  Configuration bits are grouped into registers
 * whose indexes increase downwards.  For example, with eight-bit registers,
 * sixteen gpios would have their config bits grouped in the following order:
 * REGISTER N-1 [ f e d c b a 9 8 ]
 *          N   [ 7 6 5 4 3 2 1 0 ]
 *
 * For multi-bit configurations, the pattern gets wider:
 * REGISTER N-3 [ f f e e d d c c ]
 *          N-2 [ b b a a 9 9 8 8 ]
 *          N-1 [ 7 7 6 6 5 5 4 4 ]
 *          N   [ 3 3 2 2 1 1 0 0 ]
 *
 * Given the address of the starting register 'N', the index of the gpio
 * whose configuration we seek to change, and the width in bits of that
 * configuration, these functions allow us to locate the correct
 * register and mask the correct bits.
 */
static inline void sx150x_find_cfg(u8 offset, u8 width,
				u8 *reg, u8 *mask, u8 *shift)
{
	*reg   -= offset * width / 8;
	*mask   = (1 << width) - 1;
	*shift  = (offset * width) % 8;
	*mask <<= *shift;
}

static s32 sx150x_write_cfg(struct sx150x_chip *chip,
			u8 offset, u8 width, u8 reg, u8 val)
{
	u8  mask;
	u8  data;
	u8  shift;
	s32 err;

	sx150x_find_cfg(offset, width, &reg, &mask, &shift);
	err = sx150x_i2c_read(chip->client, reg, &data);
	if (err < 0)
		return err;

	data &= ~mask;
	data |= (val << shift) & mask;
	return sx150x_i2c_write(chip->client, reg, data);
}

static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
{
	u8  reg = chip->dev_cfg->reg_data;
	u8  mask;
	u8  data;
	u8  shift;
	s32 err;

	sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
	err = sx150x_i2c_read(chip->client, reg, &data);
	if (err >= 0)
		err = (data & mask) != 0 ? 1 : 0;

	return err;
}

static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
{
	sx150x_i2c_write(chip->client,
			chip->dev_cfg->reg_clock,
			(val ? 0x1f : 0x10));
}

static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
{
	sx150x_write_cfg(chip,
			offset,
			1,
			chip->dev_cfg->reg_data,
			(val ? 1 : 0));
}

static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
{
	return sx150x_write_cfg(chip,
				offset,
				1,
				chip->dev_cfg->reg_dir,
				1);
}

static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
{
	int err;

	err = sx150x_write_cfg(chip,
			offset,
			1,
			chip->dev_cfg->reg_data,
			(val ? 1 : 0));
	if (err >= 0)
		err = sx150x_write_cfg(chip,
				offset,
				1,
				chip->dev_cfg->reg_dir,
				0);
	return err;
}

static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
{
	struct sx150x_chip *chip;
	int status = -EINVAL;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	if (!offset_is_oscio(chip, offset)) {
		mutex_lock(&chip->lock);
		status = sx150x_get_io(chip, offset);
		mutex_unlock(&chip->lock);
	}

	return status;
}

static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
{
	struct sx150x_chip *chip;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	mutex_lock(&chip->lock);
	if (offset_is_oscio(chip, offset))
		sx150x_set_oscio(chip, val);
	else
		sx150x_set_io(chip, offset, val);
	mutex_unlock(&chip->lock);
}

static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
{
	struct sx150x_chip *chip;
	int status = -EINVAL;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	if (!offset_is_oscio(chip, offset)) {
		mutex_lock(&chip->lock);
		status = sx150x_io_input(chip, offset);
		mutex_unlock(&chip->lock);
	}
	return status;
}

static int sx150x_gpio_direction_output(struct gpio_chip *gc,
					unsigned offset,
					int val)
{
	struct sx150x_chip *chip;
	int status = 0;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	if (!offset_is_oscio(chip, offset)) {
		mutex_lock(&chip->lock);
		status = sx150x_io_output(chip, offset, val);
		mutex_unlock(&chip->lock);
	}
	return status;
}

static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
	struct sx150x_chip *chip;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	if (offset >= chip->dev_cfg->ngpios)
		return -EINVAL;

	if (chip->irq_base < 0)
		return -EINVAL;

	return chip->irq_base + offset;
}

static void sx150x_irq_mask(unsigned int irq)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;
	unsigned n;

	chip = container_of(ic, struct sx150x_chip, irq_chip);
	n = irq - chip->irq_base;

	sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
	sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
}

static void sx150x_irq_unmask(unsigned int irq)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;
	unsigned n;

	chip = container_of(ic, struct sx150x_chip, irq_chip);
	n = irq - chip->irq_base;

	sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
	sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
			 chip->irq_sense >> (n * 2));
}

static int sx150x_irq_set_type(unsigned int irq, unsigned int flow_type)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;
	unsigned n, val = 0;

	if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
		return -EINVAL;

	chip = container_of(ic, struct sx150x_chip, irq_chip);
	n = irq - chip->irq_base;

	if (flow_type & IRQ_TYPE_EDGE_RISING)
		val |= 0x1;
	if (flow_type & IRQ_TYPE_EDGE_FALLING)
		val |= 0x2;

	chip->irq_sense &= ~(3UL << (n * 2));
	chip->irq_sense |= val << (n * 2);
	chip->irq_set_type_pending |= BIT(n);
	return 0;
}

static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
{
	struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
	unsigned nhandled = 0;
	unsigned sub_irq;
	unsigned n;
	s32 err;
	u8 val;
	int i;

	for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
		err = sx150x_i2c_read(chip->client,
				      chip->dev_cfg->reg_irq_src - i,
				      &val);
		if (err < 0)
			continue;

		sx150x_i2c_write(chip->client,
				chip->dev_cfg->reg_irq_src - i,
				val);
		for (n = 0; n < 8; ++n) {
			if (val & (1 << n)) {
				sub_irq = chip->irq_base + (i * 8) + n;
				handle_nested_irq(sub_irq);
				++nhandled;
			}
		}
	}

	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
}

static void sx150x_irq_bus_lock(unsigned int irq)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;

	chip = container_of(ic, struct sx150x_chip, irq_chip);

	mutex_lock(&chip->lock);
}

static void sx150x_irq_bus_sync_unlock(unsigned int irq)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;
	unsigned n;

	chip = container_of(ic, struct sx150x_chip, irq_chip);

	while (chip->irq_set_type_pending) {
		n = __ffs(chip->irq_set_type_pending);
		chip->irq_set_type_pending &= ~BIT(n);
		if (!(irq_to_desc(n + chip->irq_base)->status & IRQ_MASKED))
			sx150x_write_cfg(chip, n, 2,
					chip->dev_cfg->reg_sense,
					chip->irq_sense >> (n * 2));
	}

	mutex_unlock(&chip->lock);
}

static void sx150x_init_chip(struct sx150x_chip *chip,
			struct i2c_client *client,
			kernel_ulong_t driver_data,
			struct sx150x_platform_data *pdata)
{
	mutex_init(&chip->lock);

	chip->client                     = client;
	chip->dev_cfg                    = &sx150x_devices[driver_data];
	chip->gpio_chip.label            = client->name;
	chip->gpio_chip.direction_input  = sx150x_gpio_direction_input;
	chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
	chip->gpio_chip.get              = sx150x_gpio_get;
	chip->gpio_chip.set              = sx150x_gpio_set;
	chip->gpio_chip.to_irq           = sx150x_gpio_to_irq;
	chip->gpio_chip.base             = pdata->gpio_base;
	chip->gpio_chip.can_sleep        = 1;
	chip->gpio_chip.ngpio            = chip->dev_cfg->ngpios;
	if (pdata->oscio_is_gpo)
		++chip->gpio_chip.ngpio;

	chip->irq_chip.name            = client->name;
	chip->irq_chip.mask            = sx150x_irq_mask;
	chip->irq_chip.unmask          = sx150x_irq_unmask;
	chip->irq_chip.set_type        = sx150x_irq_set_type;
	chip->irq_chip.bus_lock        = sx150x_irq_bus_lock;
	chip->irq_chip.bus_sync_unlock = sx150x_irq_bus_sync_unlock;
	chip->irq_summary              = -1;
	chip->irq_base                 = -1;
	chip->irq_sense                = 0;
	chip->irq_set_type_pending     = 0;
}

static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
{
	int err = 0;
	unsigned n;

	for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
		err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
	return err;
}

static int sx150x_init_hw(struct sx150x_chip *chip,
			struct sx150x_platform_data *pdata)
{
	int err = 0;

	err = i2c_smbus_write_word_data(chip->client,
					chip->dev_cfg->reg_reset,
					0x3412);
	if (err < 0)
		return err;

	err = sx150x_i2c_write(chip->client,
			chip->dev_cfg->reg_misc,
			0x01);
	if (err < 0)
		return err;

	err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
			pdata->io_pullup_ena);
	if (err < 0)
		return err;

	err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
			pdata->io_pulldn_ena);
	if (err < 0)
		return err;

	err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
			pdata->io_open_drain_ena);
	if (err < 0)
		return err;

	err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
			pdata->io_polarity);
	if (err < 0)
		return err;

	if (pdata->oscio_is_gpo)
		sx150x_set_oscio(chip, 0);

	return err;
}

static int sx150x_install_irq_chip(struct sx150x_chip *chip,
				int irq_summary,
				int irq_base)
{
	int err;
	unsigned n;
	unsigned irq;

	chip->irq_summary = irq_summary;
	chip->irq_base    = irq_base;

	for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
		irq = irq_base + n;
		set_irq_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
		set_irq_nested_thread(irq, 1);
#ifdef CONFIG_ARM
		set_irq_flags(irq, IRQF_VALID);
#else
		set_irq_noprobe(irq);
#endif
	}

	err = request_threaded_irq(irq_summary,
				NULL,
				sx150x_irq_thread_fn,
				IRQF_SHARED | IRQF_TRIGGER_FALLING,
				chip->irq_chip.name,
				chip);
	if (err < 0) {
		chip->irq_summary = -1;
		chip->irq_base    = -1;
	}

	return err;
}

static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
{
	unsigned n;
	unsigned irq;

	free_irq(chip->irq_summary, chip);

	for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
		irq = chip->irq_base + n;
		set_irq_handler(irq, NULL);
		set_irq_chip(irq, NULL);
	}
}

static int __devinit sx150x_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
				     I2C_FUNC_SMBUS_WRITE_WORD_DATA;
	struct sx150x_platform_data *pdata;
	struct sx150x_chip *chip;
	int rc;

	pdata = client->dev.platform_data;
	if (!pdata)
		return -EINVAL;

	if (!i2c_check_functionality(client->adapter, i2c_funcs))
		return -ENOSYS;

	chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	sx150x_init_chip(chip, client, id->driver_data, pdata);
	rc = sx150x_init_hw(chip, pdata);
	if (rc < 0)
		goto probe_fail_pre_gpiochip_add;

	rc = gpiochip_add(&chip->gpio_chip);
	if (rc < 0)
		goto probe_fail_pre_gpiochip_add;

	if (pdata->irq_summary >= 0) {
		rc = sx150x_install_irq_chip(chip,
					pdata->irq_summary,
					pdata->irq_base);
		if (rc < 0)
			goto probe_fail_post_gpiochip_add;
	}

	i2c_set_clientdata(client, chip);

	return 0;
probe_fail_post_gpiochip_add:
	WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
probe_fail_pre_gpiochip_add:
	kfree(chip);
	return rc;
}

static int __devexit sx150x_remove(struct i2c_client *client)
{
	struct sx150x_chip *chip;
	int rc;

	chip = i2c_get_clientdata(client);
	rc = gpiochip_remove(&chip->gpio_chip);
	if (rc < 0)
		return rc;

	if (chip->irq_summary >= 0)
		sx150x_remove_irq_chip(chip);

	kfree(chip);

	return 0;
}

static struct i2c_driver sx150x_driver = {
	.driver = {
		.name = "sx150x",
		.owner = THIS_MODULE
	},
	.probe    = sx150x_probe,
	.remove   = __devexit_p(sx150x_remove),
	.id_table = sx150x_id,
};

static int __init sx150x_init(void)
{
	return i2c_add_driver(&sx150x_driver);
}
subsys_initcall(sx150x_init);

static void __exit sx150x_exit(void)
{
	return i2c_del_driver(&sx150x_driver);
}
module_exit(sx150x_exit);

MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("i2c:sx150x");
Commit	Line	Data
c34f16b7 GB	1	/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
	2	*
	3	* This program is free software; you can redistribute it and/or modify
	4	* it under the terms of the GNU General Public License version 2 and
	5	* only version 2 as published by the Free Software Foundation.
	6	*
	7	* This program is distributed in the hope that it will be useful,
	8	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	9	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	10	* GNU General Public License for more details.
	11	*
	12	* You should have received a copy of the GNU General Public License
	13	* along with this program; if not, write to the Free Software
	14	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	15	* 02110-1301, USA.
	16	*/
	17	#include <linux/gpio.h>
	18	#include <linux/i2c.h>
	19	#include <linux/init.h>
	20	#include <linux/interrupt.h>
	21	#include <linux/irq.h>
	22	#include <linux/module.h>
	23	#include <linux/mutex.h>
	24	#include <linux/slab.h>
	25	#include <linux/workqueue.h>
	26	#include <linux/i2c/sx150x.h>
	27
	28	struct sx150x_device_data {
	29	u8 reg_pullup;
	30	u8 reg_pulldn;
	31	u8 reg_drain;
	32	u8 reg_polarity;
	33	u8 reg_dir;
	34	u8 reg_data;
	35	u8 reg_irq_mask;
	36	u8 reg_irq_src;
	37	u8 reg_sense;
	38	u8 reg_clock;
	39	u8 reg_misc;
	40	u8 reg_reset;
	41	u8 ngpios;
	42	};
	43
	44	struct sx150x_chip {
	45	struct gpio_chip gpio_chip;
	46	struct i2c_client *client;
	47	const struct sx150x_device_data *dev_cfg;
	48	int irq_summary;
	49	int irq_base;
	50	u32 irq_sense;
	51	unsigned long irq_set_type_pending;
	52	struct irq_chip irq_chip;
	53	struct mutex lock;
	54	};
	55
	56	static const struct sx150x_device_data sx150x_devices[] = {
	57	[0] = { /* sx1508q */
	58	.reg_pullup = 0x03,
	59	.reg_pulldn = 0x04,
	60	.reg_drain = 0x05,
	61	.reg_polarity = 0x06,
	62	.reg_dir = 0x07,
	63	.reg_data = 0x08,
	64	.reg_irq_mask = 0x09,
65	.reg_irq_src = 0x0c,
66	.reg_sense = 0x0b,
67	.reg_clock = 0x0f,
68	.reg_misc = 0x10,
69	.reg_reset = 0x7d,
70	.ngpios = 8
71	},
72	[1] = { /* sx1509q */
73	.reg_pullup = 0x07,
74	.reg_pulldn = 0x09,
75	.reg_drain = 0x0b,
76	.reg_polarity = 0x0d,
77	.reg_dir = 0x0f,
78	.reg_data = 0x11,
79	.reg_irq_mask = 0x13,
80	.reg_irq_src = 0x19,
81	.reg_sense = 0x17,
82	.reg_clock = 0x1e,
83	.reg_misc = 0x1f,
84	.reg_reset = 0x7d,
85	.ngpios = 16
86	},
87	};
88
89	static const struct i2c_device_id sx150x_id[] = {
90	{"sx1508q", 0},
91	{"sx1509q", 1},
92	{}
93	};
94	MODULE_DEVICE_TABLE(i2c, sx150x_id);
95
96	static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
97	{
98	s32 err = i2c_smbus_write_byte_data(client, reg, val);
99
100	if (err < 0)
101	dev_warn(&client->dev,
102	"i2c write fail: can't write %02x to %02x: %d\n",
103	val, reg, err);
104	return err;
105	}
106
107	static s32 sx150x_i2c_read(struct i2c_client client, u8 reg, u8 val)
108	{
109	s32 err = i2c_smbus_read_byte_data(client, reg);
110
111	if (err >= 0)
112	*val = err;
113	else
114	dev_warn(&client->dev,
115	"i2c read fail: can't read from %02x: %d\n",
116	reg, err);
117	return err;
118	}
119
120	static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
121	{
122	return (chip->dev_cfg->ngpios == offset);
123	}
124
125	/*
126	* These utility functions solve the common problem of locating and setting
127	* configuration bits. Configuration bits are grouped into registers
128	* whose indexes increase downwards. For example, with eight-bit registers,
129	* sixteen gpios would have their config bits grouped in the following order:
130	* REGISTER N-1 [ f e d c b a 9 8 ]
131	* N [ 7 6 5 4 3 2 1 0 ]
132	*
133	* For multi-bit configurations, the pattern gets wider:
134	* REGISTER N-3 [ f f e e d d c c ]
135	* N-2 [ b b a a 9 9 8 8 ]
136	* N-1 [ 7 7 6 6 5 5 4 4 ]
137	* N [ 3 3 2 2 1 1 0 0 ]
138	*
139	* Given the address of the starting register 'N', the index of the gpio
140	* whose configuration we seek to change, and the width in bits of that
141	* configuration, these functions allow us to locate the correct
142	* register and mask the correct bits.
143	*/
144	static inline void sx150x_find_cfg(u8 offset, u8 width,
145	u8 reg, u8 mask, u8 *shift)
146	{
147	reg -= offset width / 8;
148	*mask = (1 << width) - 1;
149	shift = (offset width) % 8;
150	mask <<= shift;
151	}
152
153	static s32 sx150x_write_cfg(struct sx150x_chip *chip,
154	u8 offset, u8 width, u8 reg, u8 val)
155	{
156	u8 mask;
157	u8 data;
158	u8 shift;
159	s32 err;
160
161	sx150x_find_cfg(offset, width, &reg, &mask, &shift);
162	err = sx150x_i2c_read(chip->client, reg, &data);
163	if (err < 0)
164	return err;
165
166	data &= ~mask;
167	data \|= (val << shift) & mask;
168	return sx150x_i2c_write(chip->client, reg, data);
169	}
170
171	static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
172	{
173	u8 reg = chip->dev_cfg->reg_data;
174	u8 mask;
175	u8 data;
176	u8 shift;
177	s32 err;
178
179	sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
180	err = sx150x_i2c_read(chip->client, reg, &data);
181	if (err >= 0)
182	err = (data & mask) != 0 ? 1 : 0;
183
184	return err;
185	}
186
187	static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
188	{
189	sx150x_i2c_write(chip->client,
190	chip->dev_cfg->reg_clock,
191	(val ? 0x1f : 0x10));
192	}
193
194	static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
195	{
196	sx150x_write_cfg(chip,
197	offset,
198	1,
199	chip->dev_cfg->reg_data,
200	(val ? 1 : 0));
201	}
202
203	static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
204	{
205	return sx150x_write_cfg(chip,
206	offset,
207	1,
208	chip->dev_cfg->reg_dir,
209	1);
210	}
211
212	static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
213	{
214	int err;
215
216	err = sx150x_write_cfg(chip,
217	offset,
218	1,
219	chip->dev_cfg->reg_data,
220	(val ? 1 : 0));
221	if (err >= 0)
222	err = sx150x_write_cfg(chip,
223	offset,
224	1,
225	chip->dev_cfg->reg_dir,
226	0);
227	return err;
228	}
229
230	static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
231	{
232	struct sx150x_chip *chip;
233	int status = -EINVAL;
234
235	chip = container_of(gc, struct sx150x_chip, gpio_chip);
236
237	if (!offset_is_oscio(chip, offset)) {
238	mutex_lock(&chip->lock);
239	status = sx150x_get_io(chip, offset);
240	mutex_unlock(&chip->lock);
241	}
242
243	return status;
244	}
245
246	static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
247	{
248	struct sx150x_chip *chip;
249
250	chip = container_of(gc, struct sx150x_chip, gpio_chip);
251
252	mutex_lock(&chip->lock);
253	if (offset_is_oscio(chip, offset))
254	sx150x_set_oscio(chip, val);
255	else
256	sx150x_set_io(chip, offset, val);
257	mutex_unlock(&chip->lock);
258	}
259
260	static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
261	{
262	struct sx150x_chip *chip;
263	int status = -EINVAL;
264
265	chip = container_of(gc, struct sx150x_chip, gpio_chip);
266
267	if (!offset_is_oscio(chip, offset)) {
268	mutex_lock(&chip->lock);
269	status = sx150x_io_input(chip, offset);
270	mutex_unlock(&chip->lock);
271	}
272	return status;
273	}
274
275	static int sx150x_gpio_direction_output(struct gpio_chip *gc,
276	unsigned offset,
277	int val)
278	{
279	struct sx150x_chip *chip;
280	int status = 0;
281
282	chip = container_of(gc, struct sx150x_chip, gpio_chip);
283
284	if (!offset_is_oscio(chip, offset)) {
285	mutex_lock(&chip->lock);
286	status = sx150x_io_output(chip, offset, val);
287	mutex_unlock(&chip->lock);
288	}
289	return status;
290	}
291
292	static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
293	{
294	struct sx150x_chip *chip;
295
296	chip = container_of(gc, struct sx150x_chip, gpio_chip);
297
298	if (offset >= chip->dev_cfg->ngpios)
299	return -EINVAL;
300
301	if (chip->irq_base < 0)
302	return -EINVAL;
303
304	return chip->irq_base + offset;
305	}
306
307	static void sx150x_irq_mask(unsigned int irq)
308	{
309	struct irq_chip *ic = get_irq_chip(irq);
310	struct sx150x_chip *chip;
311	unsigned n;
312
313	chip = container_of(ic, struct sx150x_chip, irq_chip);
314	n = irq - chip->irq_base;
315
316	sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
317	sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
318	}
319
320	static void sx150x_irq_unmask(unsigned int irq)
321	{
322	struct irq_chip *ic = get_irq_chip(irq);
323	struct sx150x_chip *chip;
324	unsigned n;
325
326	chip = container_of(ic, struct sx150x_chip, irq_chip);
327	n = irq - chip->irq_base;
328
329	sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
330	sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
331	chip->irq_sense >> (n * 2));
332	}
333
334	static int sx150x_irq_set_type(unsigned int irq, unsigned int flow_type)
335	{
336	struct irq_chip *ic = get_irq_chip(irq);
337	struct sx150x_chip *chip;
338	unsigned n, val = 0;
339
340	if (flow_type & (IRQ_TYPE_LEVEL_HIGH \| IRQ_TYPE_LEVEL_LOW))
341	return -EINVAL;
342
343	chip = container_of(ic, struct sx150x_chip, irq_chip);
344	n = irq - chip->irq_base;
345
346	if (flow_type & IRQ_TYPE_EDGE_RISING)
347	val \|= 0x1;
348	if (flow_type & IRQ_TYPE_EDGE_FALLING)
349	val \|= 0x2;
350
351	chip->irq_sense &= ~(3UL << (n * 2));
352	chip->irq_sense \|= val << (n * 2);
353	chip->irq_set_type_pending \|= BIT(n);
354	return 0;
355	}
356
357	static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
358	{
359	struct sx150x_chip chip = (struct sx150x_chip )dev_id;
360	unsigned nhandled = 0;
361	unsigned sub_irq;
362	unsigned n;
363	s32 err;
364	u8 val;
365	int i;
366
367	for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
368	err = sx150x_i2c_read(chip->client,
369	chip->dev_cfg->reg_irq_src - i,
370	&val);
371	if (err < 0)
372	continue;
373
374	sx150x_i2c_write(chip->client,
375	chip->dev_cfg->reg_irq_src - i,
376	val);
377	for (n = 0; n < 8; ++n) {
378	if (val & (1 << n)) {
379	sub_irq = chip->irq_base + (i * 8) + n;
380	handle_nested_irq(sub_irq);
381	++nhandled;
382	}
383	}
384	}
385
386	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
387	}
388
389	static void sx150x_irq_bus_lock(unsigned int irq)
390	{
391	struct irq_chip *ic = get_irq_chip(irq);
392	struct sx150x_chip *chip;
393
394	chip = container_of(ic, struct sx150x_chip, irq_chip);
395
396	mutex_lock(&chip->lock);
397	}
398
399	static void sx150x_irq_bus_sync_unlock(unsigned int irq)
400	{
401	struct irq_chip *ic = get_irq_chip(irq);
402	struct sx150x_chip *chip;
403	unsigned n;
404
405	chip = container_of(ic, struct sx150x_chip, irq_chip);
406
407	while (chip->irq_set_type_pending) {
408	n = __ffs(chip->irq_set_type_pending);
409	chip->irq_set_type_pending &= ~BIT(n);
410	if (!(irq_to_desc(n + chip->irq_base)->status & IRQ_MASKED))
411	sx150x_write_cfg(chip, n, 2,
412	chip->dev_cfg->reg_sense,
413	chip->irq_sense >> (n * 2));
414	}
415
416	mutex_unlock(&chip->lock);
417	}
418
419	static void sx150x_init_chip(struct sx150x_chip *chip,
420	struct i2c_client *client,
421	kernel_ulong_t driver_data,
422	struct sx150x_platform_data *pdata)
423	{
424	mutex_init(&chip->lock);
425
426	chip->client = client;
427	chip->dev_cfg = &sx150x_devices[driver_data];
428	chip->gpio_chip.label = client->name;
429	chip->gpio_chip.direction_input = sx150x_gpio_direction_input;
430	chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
431	chip->gpio_chip.get = sx150x_gpio_get;
432	chip->gpio_chip.set = sx150x_gpio_set;
433	chip->gpio_chip.to_irq = sx150x_gpio_to_irq;
434	chip->gpio_chip.base = pdata->gpio_base;
435	chip->gpio_chip.can_sleep = 1;
436	chip->gpio_chip.ngpio = chip->dev_cfg->ngpios;
437	if (pdata->oscio_is_gpo)
438	++chip->gpio_chip.ngpio;
439
440	chip->irq_chip.name = client->name;
441	chip->irq_chip.mask = sx150x_irq_mask;
442	chip->irq_chip.unmask = sx150x_irq_unmask;
443	chip->irq_chip.set_type = sx150x_irq_set_type;
444	chip->irq_chip.bus_lock = sx150x_irq_bus_lock;
445	chip->irq_chip.bus_sync_unlock = sx150x_irq_bus_sync_unlock;
446	chip->irq_summary = -1;
447	chip->irq_base = -1;
448	chip->irq_sense = 0;
449	chip->irq_set_type_pending = 0;
450	}
451
452	static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
453	{
454	int err = 0;
455	unsigned n;
456
457	for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
458	err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
459	return err;
460	}
461
462	static int sx150x_init_hw(struct sx150x_chip *chip,
463	struct sx150x_platform_data *pdata)
464	{
465	int err = 0;
466
467	err = i2c_smbus_write_word_data(chip->client,
468	chip->dev_cfg->reg_reset,
469	0x3412);
470	if (err < 0)
471	return err;
472
473	err = sx150x_i2c_write(chip->client,
474	chip->dev_cfg->reg_misc,
475	0x01);
476	if (err < 0)
477	return err;
478
479	err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
480	pdata->io_pullup_ena);
481	if (err < 0)
482	return err;
483
484	err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
485	pdata->io_pulldn_ena);
486	if (err < 0)
487	return err;
488
489	err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
490	pdata->io_open_drain_ena);
491	if (err < 0)
492	return err;
493
494	err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
495	pdata->io_polarity);
496	if (err < 0)
497	return err;
498
499	if (pdata->oscio_is_gpo)
500	sx150x_set_oscio(chip, 0);
501
502	return err;
503	}
504
505	static int sx150x_install_irq_chip(struct sx150x_chip *chip,
506	int irq_summary,
507	int irq_base)
508	{
509	int err;
510	unsigned n;
511	unsigned irq;
512
513	chip->irq_summary = irq_summary;
514	chip->irq_base = irq_base;
515
516	for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
517	irq = irq_base + n;
518	set_irq_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
519	set_irq_nested_thread(irq, 1);
520	#ifdef CONFIG_ARM
521	set_irq_flags(irq, IRQF_VALID);
522	#else
523	set_irq_noprobe(irq);
524	#endif
525	}
526
527	err = request_threaded_irq(irq_summary,
528	NULL,
529	sx150x_irq_thread_fn,
530	IRQF_SHARED \| IRQF_TRIGGER_FALLING,
531	chip->irq_chip.name,
532	chip);
533	if (err < 0) {
534	chip->irq_summary = -1;
535	chip->irq_base = -1;
536	}
537
538	return err;
539	}
540
541	static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
542	{
543	unsigned n;
544	unsigned irq;
545
546	free_irq(chip->irq_summary, chip);
547
548	for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
549	irq = chip->irq_base + n;
550	set_irq_handler(irq, NULL);
551	set_irq_chip(irq, NULL);
552	}
553	}
554
555	static int __devinit sx150x_probe(struct i2c_client *client,
556	const struct i2c_device_id *id)
557	{
558	static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA \|
559	I2C_FUNC_SMBUS_WRITE_WORD_DATA;
560	struct sx150x_platform_data *pdata;
561	struct sx150x_chip *chip;
562	int rc;
563
564	pdata = client->dev.platform_data;
565	if (!pdata)
566	return -EINVAL;
567
568	if (!i2c_check_functionality(client->adapter, i2c_funcs))
569	return -ENOSYS;
570
571	chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
572	if (!chip)
573	return -ENOMEM;
574
575	sx150x_init_chip(chip, client, id->driver_data, pdata);
576	rc = sx150x_init_hw(chip, pdata);
577	if (rc < 0)
578	goto probe_fail_pre_gpiochip_add;
579
580	rc = gpiochip_add(&chip->gpio_chip);
581	if (rc < 0)
582	goto probe_fail_pre_gpiochip_add;
583
584	if (pdata->irq_summary >= 0) {
585	rc = sx150x_install_irq_chip(chip,
586	pdata->irq_summary,
587	pdata->irq_base);
588	if (rc < 0)
589	goto probe_fail_post_gpiochip_add;
590	}
591
592	i2c_set_clientdata(client, chip);
593
594	return 0;
595	probe_fail_post_gpiochip_add:
596	WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
597	probe_fail_pre_gpiochip_add:
598	kfree(chip);
599	return rc;
600	}
601
602	static int __devexit sx150x_remove(struct i2c_client *client)
603	{
604	struct sx150x_chip *chip;
605	int rc;
606
607	chip = i2c_get_clientdata(client);
608	rc = gpiochip_remove(&chip->gpio_chip);
609	if (rc < 0)
610	return rc;
611
612	if (chip->irq_summary >= 0)
613	sx150x_remove_irq_chip(chip);
614
615	kfree(chip);
616
617	return 0;
618	}
619
620	static struct i2c_driver sx150x_driver = {
621	.driver = {
622	.name = "sx150x",
623	.owner = THIS_MODULE
624	},
625	.probe = sx150x_probe,
626	.remove = __devexit_p(sx150x_remove),
627	.id_table = sx150x_id,
628	};
629
630	static int __init sx150x_init(void)
631	{
632	return i2c_add_driver(&sx150x_driver);
633	}
634	subsys_initcall(sx150x_init);
635
636	static void __exit sx150x_exit(void)
637	{
638	return i2c_del_driver(&sx150x_driver);
639	}
640	module_exit(sx150x_exit);
641
642	MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
643	MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
644	MODULE_LICENSE("GPL v2");
645	MODULE_ALIAS("i2c:sx150x");