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32 results

gpio-pca953x.c

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  • gpio-pca953x.c 24.04 KiB
    /*
     *  PCA953x 4/8/16/24/40 bit I/O ports
     *
     *  Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
     *  Copyright (C) 2007 Marvell International Ltd.
     *
     *  Derived from drivers/i2c/chips/pca9539.c
     *
     *  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; version 2 of the License.
     */
    
    #include <linux/module.h>
    #include <linux/init.h>
    #include <linux/gpio.h>
    #include <linux/interrupt.h>
    #include <linux/i2c.h>
    #include <linux/platform_data/pca953x.h>
    #include <linux/slab.h>
    #include <asm/unaligned.h>
    #include <linux/of_platform.h>
    #include <linux/acpi.h>
    #include <linux/regulator/consumer.h>
    
    #define PCA953X_INPUT		0
    #define PCA953X_OUTPUT		1
    #define PCA953X_INVERT		2
    #define PCA953X_DIRECTION	3
    
    #define REG_ADDR_AI		0x80
    
    #define PCA957X_IN		0
    #define PCA957X_INVRT		1
    #define PCA957X_BKEN		2
    #define PCA957X_PUPD		3
    #define PCA957X_CFG		4
    #define PCA957X_OUT		5
    #define PCA957X_MSK		6
    #define PCA957X_INTS		7
    
    #define PCAL953X_IN_LATCH	34
    #define PCAL953X_INT_MASK	37
    #define PCAL953X_INT_STAT	38
    
    #define PCA_GPIO_MASK		0x00FF
    #define PCA_INT			0x0100
    #define PCA_PCAL		0x0200
    #define PCA953X_TYPE		0x1000
    #define PCA957X_TYPE		0x2000
    #define PCA_TYPE_MASK		0xF000
    
    #define PCA_CHIP_TYPE(x)	((x) & PCA_TYPE_MASK)
    
    static const struct i2c_device_id pca953x_id[] = {
    	{ "pca9505", 40 | PCA953X_TYPE | PCA_INT, },
    	{ "pca9534", 8  | PCA953X_TYPE | PCA_INT, },
    	{ "pca9535", 16 | PCA953X_TYPE | PCA_INT, },
    	{ "pca9536", 4  | PCA953X_TYPE, },
    	{ "pca9537", 4  | PCA953X_TYPE | PCA_INT, },
    	{ "pca9538", 8  | PCA953X_TYPE | PCA_INT, },
    	{ "pca9539", 16 | PCA953X_TYPE | PCA_INT, },
    	{ "pca9554", 8  | PCA953X_TYPE | PCA_INT, },
    	{ "pca9555", 16 | PCA953X_TYPE | PCA_INT, },
    	{ "pca9556", 8  | PCA953X_TYPE, },
    	{ "pca9557", 8  | PCA953X_TYPE, },
    	{ "pca9574", 8  | PCA957X_TYPE | PCA_INT, },
    	{ "pca9575", 16 | PCA957X_TYPE | PCA_INT, },
    	{ "pca9698", 40 | PCA953X_TYPE, },
    
    	{ "pcal9555a", 16 | PCA953X_TYPE | PCA_INT | PCA_PCAL, },
    
    	{ "max7310", 8  | PCA953X_TYPE, },
    	{ "max7312", 16 | PCA953X_TYPE | PCA_INT, },
    	{ "max7313", 16 | PCA953X_TYPE | PCA_INT, },
    	{ "max7315", 8  | PCA953X_TYPE | PCA_INT, },
    	{ "pca6107", 8  | PCA953X_TYPE | PCA_INT, },
    	{ "tca6408", 8  | PCA953X_TYPE | PCA_INT, },
    	{ "tca6416", 16 | PCA953X_TYPE | PCA_INT, },
    	{ "tca6424", 24 | PCA953X_TYPE | PCA_INT, },
    	{ "tca9539", 16 | PCA953X_TYPE | PCA_INT, },
    	{ "xra1202", 8  | PCA953X_TYPE },
    	{ }
    };
    MODULE_DEVICE_TABLE(i2c, pca953x_id);
    
    static const struct acpi_device_id pca953x_acpi_ids[] = {
    	{ "INT3491", 16 | PCA953X_TYPE | PCA_INT | PCA_PCAL, },
    	{ }
    };
    MODULE_DEVICE_TABLE(acpi, pca953x_acpi_ids);
    
    #define MAX_BANK 5
    #define BANK_SZ 8
    
    #define NBANK(chip) DIV_ROUND_UP(chip->gpio_chip.ngpio, BANK_SZ)
    
    struct pca953x_reg_config {
    	int direction;
    	int output;
    	int input;
    };
    
    static const struct pca953x_reg_config pca953x_regs = {
    	.direction = PCA953X_DIRECTION,
    	.output = PCA953X_OUTPUT,
    	.input = PCA953X_INPUT,
    };
    
    static const struct pca953x_reg_config pca957x_regs = {
    	.direction = PCA957X_CFG,
    	.output = PCA957X_OUT,
    	.input = PCA957X_IN,
    };
    
    struct pca953x_chip {
    	unsigned gpio_start;
    	u8 reg_output[MAX_BANK];
    	u8 reg_direction[MAX_BANK];
    	struct mutex i2c_lock;
    
    #ifdef CONFIG_GPIO_PCA953X_IRQ
    	struct mutex irq_lock;
    	u8 irq_mask[MAX_BANK];
    	u8 irq_stat[MAX_BANK];
    	u8 irq_trig_raise[MAX_BANK];
    	u8 irq_trig_fall[MAX_BANK];
    #endif
    
    	struct i2c_client *client;
    	struct gpio_chip gpio_chip;
    	const char *const *names;
    	unsigned long driver_data;
    	struct regulator *regulator;
    
    	const struct pca953x_reg_config *regs;
    
    	int (*write_regs)(struct pca953x_chip *, int, u8 *);
    	int (*read_regs)(struct pca953x_chip *, int, u8 *);
    };
    
    static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
    				int off)
    {
    	int ret;
    	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
    	int offset = off / BANK_SZ;
    
    	ret = i2c_smbus_read_byte_data(chip->client,
    				(reg << bank_shift) + offset);
    	*val = ret;
    
    	if (ret < 0) {
    		dev_err(&chip->client->dev, "failed reading register\n");
    		return ret;
    	}
    
    	return 0;
    }
    
    static int pca953x_write_single(struct pca953x_chip *chip, int reg, u32 val,
    				int off)
    {
    	int ret;
    	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
    	int offset = off / BANK_SZ;
    
    	ret = i2c_smbus_write_byte_data(chip->client,
    					(reg << bank_shift) + offset, val);
    
    	if (ret < 0) {
    		dev_err(&chip->client->dev, "failed writing register\n");
    		return ret;
    	}
    
    	return 0;
    }
    
    static int pca953x_write_regs_8(struct pca953x_chip *chip, int reg, u8 *val)
    {
    	return i2c_smbus_write_byte_data(chip->client, reg, *val);
    }
    
    static int pca953x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
    {
    	__le16 word = cpu_to_le16(get_unaligned((u16 *)val));
    
    	return i2c_smbus_write_word_data(chip->client,
    					 reg << 1, (__force u16)word);
    }
    
    static int pca957x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
    {
    	int ret;
    
    	ret = i2c_smbus_write_byte_data(chip->client, reg << 1, val[0]);
    	if (ret < 0)
    		return ret;
    
    	return i2c_smbus_write_byte_data(chip->client, (reg << 1) + 1, val[1]);
    }
    
    static int pca953x_write_regs_24(struct pca953x_chip *chip, int reg, u8 *val)
    {
    	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
    
    	return i2c_smbus_write_i2c_block_data(chip->client,
    					      (reg << bank_shift) | REG_ADDR_AI,
    					      NBANK(chip), val);
    }
    
    static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
    {
    	int ret = 0;
    
    	ret = chip->write_regs(chip, reg, val);
    	if (ret < 0) {
    		dev_err(&chip->client->dev, "failed writing register\n");
    		return ret;
    	}
    
    	return 0;
    }
    
    static int pca953x_read_regs_8(struct pca953x_chip *chip, int reg, u8 *val)
    {
    	int ret;
    
    	ret = i2c_smbus_read_byte_data(chip->client, reg);
    	*val = ret;
    
    	return ret;
    }
    
    static int pca953x_read_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
    {
    	int ret;
    
    	ret = i2c_smbus_read_word_data(chip->client, reg << 1);
    	val[0] = (u16)ret & 0xFF;
    	val[1] = (u16)ret >> 8;
    
    	return ret;
    }
    
    static int pca953x_read_regs_24(struct pca953x_chip *chip, int reg, u8 *val)
    {
    	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
    
    	return i2c_smbus_read_i2c_block_data(chip->client,
    					     (reg << bank_shift) | REG_ADDR_AI,
    					     NBANK(chip), val);
    }
    
    static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
    {
    	int ret;
    
    	ret = chip->read_regs(chip, reg, val);
    	if (ret < 0) {
    		dev_err(&chip->client->dev, "failed reading register\n");
    		return ret;
    	}
    
    	return 0;
    }
    
    static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
    {
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    	u8 reg_val;
    	int ret;
    
    	mutex_lock(&chip->i2c_lock);
    	reg_val = chip->reg_direction[off / BANK_SZ] | (1u << (off % BANK_SZ));
    
    	ret = pca953x_write_single(chip, chip->regs->direction, reg_val, off);
    	if (ret)
    		goto exit;
    
    	chip->reg_direction[off / BANK_SZ] = reg_val;
    exit:
    	mutex_unlock(&chip->i2c_lock);
    	return ret;
    }
    
    static int pca953x_gpio_direction_output(struct gpio_chip *gc,
    		unsigned off, int val)
    {
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    	u8 reg_val;
    	int ret;
    
    	mutex_lock(&chip->i2c_lock);
    	/* set output level */
    	if (val)
    		reg_val = chip->reg_output[off / BANK_SZ]
    			| (1u << (off % BANK_SZ));
    	else
    		reg_val = chip->reg_output[off / BANK_SZ]
    			& ~(1u << (off % BANK_SZ));
    
    	ret = pca953x_write_single(chip, chip->regs->output, reg_val, off);
    	if (ret)
    		goto exit;
    
    	chip->reg_output[off / BANK_SZ] = reg_val;
    
    	/* then direction */
    	reg_val = chip->reg_direction[off / BANK_SZ] & ~(1u << (off % BANK_SZ));
    	ret = pca953x_write_single(chip, chip->regs->direction, reg_val, off);
    	if (ret)
    		goto exit;
    
    	chip->reg_direction[off / BANK_SZ] = reg_val;
    exit:
    	mutex_unlock(&chip->i2c_lock);
    	return ret;
    }
    
    static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
    {
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    	u32 reg_val;
    	int ret;
    
    	mutex_lock(&chip->i2c_lock);
    	ret = pca953x_read_single(chip, chip->regs->input, &reg_val, off);
    	mutex_unlock(&chip->i2c_lock);
    	if (ret < 0) {
    		/* NOTE:  diagnostic already emitted; that's all we should
    		 * do unless gpio_*_value_cansleep() calls become different
    		 * from their nonsleeping siblings (and report faults).
    		 */
    		return 0;
    	}
    
    	return (reg_val & (1u << (off % BANK_SZ))) ? 1 : 0;
    }
    
    static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
    {
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    	u8 reg_val;
    	int ret;
    
    	mutex_lock(&chip->i2c_lock);
    	if (val)
    		reg_val = chip->reg_output[off / BANK_SZ]
    			| (1u << (off % BANK_SZ));
    	else
    		reg_val = chip->reg_output[off / BANK_SZ]
    			& ~(1u << (off % BANK_SZ));
    
    	ret = pca953x_write_single(chip, chip->regs->output, reg_val, off);
    	if (ret)
    		goto exit;
    
    	chip->reg_output[off / BANK_SZ] = reg_val;
    exit:
    	mutex_unlock(&chip->i2c_lock);
    }
    
    static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
    				      unsigned long *mask, unsigned long *bits)
    {
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    	unsigned int bank_mask, bank_val;
    	int bank_shift, bank;
    	u8 reg_val[MAX_BANK];
    	int ret;
    
    	bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
    
    	mutex_lock(&chip->i2c_lock);
    	memcpy(reg_val, chip->reg_output, NBANK(chip));
    	for (bank = 0; bank < NBANK(chip); bank++) {
    		bank_mask = mask[bank / sizeof(*mask)] >>
    			   ((bank % sizeof(*mask)) * 8);
    		if (bank_mask) {
    			bank_val = bits[bank / sizeof(*bits)] >>
    				  ((bank % sizeof(*bits)) * 8);
    			bank_val &= bank_mask;
    			reg_val[bank] = (reg_val[bank] & ~bank_mask) | bank_val;
    		}
    	}
    
    	ret = i2c_smbus_write_i2c_block_data(chip->client,
    					     chip->regs->output << bank_shift,
    					     NBANK(chip), reg_val);
    	if (ret)
    		goto exit;
    
    	memcpy(chip->reg_output, reg_val, NBANK(chip));
    exit:
    	mutex_unlock(&chip->i2c_lock);
    }
    
    static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
    {
    	struct gpio_chip *gc;
    
    	gc = &chip->gpio_chip;
    
    	gc->direction_input  = pca953x_gpio_direction_input;
    	gc->direction_output = pca953x_gpio_direction_output;
    	gc->get = pca953x_gpio_get_value;
    	gc->set = pca953x_gpio_set_value;
    	gc->set_multiple = pca953x_gpio_set_multiple;
    	gc->can_sleep = true;
    
    	gc->base = chip->gpio_start;
    	gc->ngpio = gpios;
    	gc->label = chip->client->name;
    	gc->parent = &chip->client->dev;
    	gc->owner = THIS_MODULE;
    	gc->names = chip->names;
    }
    
    #ifdef CONFIG_GPIO_PCA953X_IRQ
    static void pca953x_irq_mask(struct irq_data *d)
    {
    	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    
    	chip->irq_mask[d->hwirq / BANK_SZ] &= ~(1 << (d->hwirq % BANK_SZ));
    }
    
    static void pca953x_irq_unmask(struct irq_data *d)
    {
    	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    
    	chip->irq_mask[d->hwirq / BANK_SZ] |= 1 << (d->hwirq % BANK_SZ);
    }
    
    static void pca953x_irq_bus_lock(struct irq_data *d)
    {
    	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    
    	mutex_lock(&chip->irq_lock);
    }
    
    static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
    {
    	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    	u8 new_irqs;
    	int level, i;
    	u8 invert_irq_mask[MAX_BANK];
    
    	if (chip->driver_data & PCA_PCAL) {
    		/* Enable latch on interrupt-enabled inputs */
    		pca953x_write_regs(chip, PCAL953X_IN_LATCH, chip->irq_mask);
    
    		for (i = 0; i < NBANK(chip); i++)
    			invert_irq_mask[i] = ~chip->irq_mask[i];
    
    		/* Unmask enabled interrupts */
    		pca953x_write_regs(chip, PCAL953X_INT_MASK, invert_irq_mask);
    	}
    
    	/* Look for any newly setup interrupt */
    	for (i = 0; i < NBANK(chip); i++) {
    		new_irqs = chip->irq_trig_fall[i] | chip->irq_trig_raise[i];
    		new_irqs &= ~chip->reg_direction[i];
    
    		while (new_irqs) {
    			level = __ffs(new_irqs);
    			pca953x_gpio_direction_input(&chip->gpio_chip,
    							level + (BANK_SZ * i));
    			new_irqs &= ~(1 << level);
    		}
    	}
    
    	mutex_unlock(&chip->irq_lock);
    }
    
    static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
    {
    	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
    	struct pca953x_chip *chip = gpiochip_get_data(gc);
    	int bank_nb = d->hwirq / BANK_SZ;
    	u8 mask = 1 << (d->hwirq % BANK_SZ);
    
    	if (!(type & IRQ_TYPE_EDGE_BOTH)) {
    		dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
    			d->irq, type);
    		return -EINVAL;
    	}
    
    	if (type & IRQ_TYPE_EDGE_FALLING)
    		chip->irq_trig_fall[bank_nb] |= mask;
    	else
    		chip->irq_trig_fall[bank_nb] &= ~mask;
    
    	if (type & IRQ_TYPE_EDGE_RISING)
    		chip->irq_trig_raise[bank_nb] |= mask;
    	else
    		chip->irq_trig_raise[bank_nb] &= ~mask;
    
    	return 0;
    }
    
    static struct irq_chip pca953x_irq_chip = {
    	.name			= "pca953x",
    	.irq_mask		= pca953x_irq_mask,
    	.irq_unmask		= pca953x_irq_unmask,
    	.irq_bus_lock		= pca953x_irq_bus_lock,
    	.irq_bus_sync_unlock	= pca953x_irq_bus_sync_unlock,
    	.irq_set_type		= pca953x_irq_set_type,
    };
    
    static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
    {
    	u8 cur_stat[MAX_BANK];
    	u8 old_stat[MAX_BANK];
    	bool pending_seen = false;
    	bool trigger_seen = false;
    	u8 trigger[MAX_BANK];
    	int ret, i;
    
    	if (chip->driver_data & PCA_PCAL) {
    		/* Read the current interrupt status from the device */
    		ret = pca953x_read_regs(chip, PCAL953X_INT_STAT, trigger);
    		if (ret)
    			return false;
    
    		/* Check latched inputs and clear interrupt status */
    		ret = pca953x_read_regs(chip, PCA953X_INPUT, cur_stat);
    		if (ret)
    			return false;
    
    		for (i = 0; i < NBANK(chip); i++) {
    			/* Apply filter for rising/falling edge selection */
    			pending[i] = (~cur_stat[i] & chip->irq_trig_fall[i]) |
    				(cur_stat[i] & chip->irq_trig_raise[i]);
    			pending[i] &= trigger[i];
    			if (pending[i])
    				pending_seen = true;
    		}
    
    		return pending_seen;
    	}
    
    	ret = pca953x_read_regs(chip, chip->regs->input, cur_stat);
    	if (ret)
    		return false;
    
    	/* Remove output pins from the equation */
    	for (i = 0; i < NBANK(chip); i++)
    		cur_stat[i] &= chip->reg_direction[i];
    
    	memcpy(old_stat, chip->irq_stat, NBANK(chip));
    
    	for (i = 0; i < NBANK(chip); i++) {
    		trigger[i] = (cur_stat[i] ^ old_stat[i]) & chip->irq_mask[i];
    		if (trigger[i])
    			trigger_seen = true;
    	}
    
    	if (!trigger_seen)
    		return false;
    
    	memcpy(chip->irq_stat, cur_stat, NBANK(chip));
    
    	for (i = 0; i < NBANK(chip); i++) {
    		pending[i] = (old_stat[i] & chip->irq_trig_fall[i]) |
    			(cur_stat[i] & chip->irq_trig_raise[i]);
    		pending[i] &= trigger[i];
    		if (pending[i])
    			pending_seen = true;
    	}
    
    	return pending_seen;
    }
    
    static irqreturn_t pca953x_irq_handler(int irq, void *devid)
    {
    	struct pca953x_chip *chip = devid;
    	u8 pending[MAX_BANK];
    	u8 level;
    	unsigned nhandled = 0;
    	int i;
    
    	if (!pca953x_irq_pending(chip, pending))
    		return IRQ_NONE;
    
    	for (i = 0; i < NBANK(chip); i++) {
    		while (pending[i]) {
    			level = __ffs(pending[i]);
    			handle_nested_irq(irq_find_mapping(chip->gpio_chip.irqdomain,
    							level + (BANK_SZ * i)));
    			pending[i] &= ~(1 << level);
    			nhandled++;
    		}
    	}
    
    	return (nhandled > 0) ? IRQ_HANDLED : IRQ_NONE;
    }
    
    static int pca953x_irq_setup(struct pca953x_chip *chip,
    			     int irq_base)
    {
    	struct i2c_client *client = chip->client;
    	int ret, i;
    
    	if (client->irq && irq_base != -1
    			&& (chip->driver_data & PCA_INT)) {
    		ret = pca953x_read_regs(chip,
    					chip->regs->input, chip->irq_stat);
    		if (ret)
    			return ret;
    
    		/*
    		 * There is no way to know which GPIO line generated the
    		 * interrupt.  We have to rely on the previous read for
    		 * this purpose.
    		 */
    		for (i = 0; i < NBANK(chip); i++)
    			chip->irq_stat[i] &= chip->reg_direction[i];
    		mutex_init(&chip->irq_lock);
    
    		ret = devm_request_threaded_irq(&client->dev,
    					client->irq,
    					   NULL,
    					   pca953x_irq_handler,
    					   IRQF_TRIGGER_LOW | IRQF_ONESHOT |
    						   IRQF_SHARED,
    					   dev_name(&client->dev), chip);
    		if (ret) {
    			dev_err(&client->dev, "failed to request irq %d\n",
    				client->irq);
    			return ret;
    		}
    
    		ret =  gpiochip_irqchip_add(&chip->gpio_chip,
    					    &pca953x_irq_chip,
    					    irq_base,
    					    handle_simple_irq,
    					    IRQ_TYPE_NONE);
    		if (ret) {
    			dev_err(&client->dev,
    				"could not connect irqchip to gpiochip\n");
    			return ret;
    		}
    
    		gpiochip_set_chained_irqchip(&chip->gpio_chip,
    					     &pca953x_irq_chip,
    					     client->irq, NULL);
    	}
    
    	return 0;
    }
    
    #else /* CONFIG_GPIO_PCA953X_IRQ */
    static int pca953x_irq_setup(struct pca953x_chip *chip,
    			     int irq_base)
    {
    	struct i2c_client *client = chip->client;
    
    	if (irq_base != -1 && (chip->driver_data & PCA_INT))
    		dev_warn(&client->dev, "interrupt support not compiled in\n");
    
    	return 0;
    }
    #endif
    
    static int device_pca953x_init(struct pca953x_chip *chip, u32 invert)
    {
    	int ret;
    	u8 val[MAX_BANK];
    
    	chip->regs = &pca953x_regs;
    
    	ret = pca953x_read_regs(chip, chip->regs->output, chip->reg_output);
    	if (ret)
    		goto out;
    
    	ret = pca953x_read_regs(chip, chip->regs->direction,
    				chip->reg_direction);
    	if (ret)
    		goto out;
    
    	/* set platform specific polarity inversion */
    	if (invert)
    		memset(val, 0xFF, NBANK(chip));
    	else
    		memset(val, 0, NBANK(chip));
    
    	ret = pca953x_write_regs(chip, PCA953X_INVERT, val);
    out:
    	return ret;
    }
    
    static int device_pca957x_init(struct pca953x_chip *chip, u32 invert)
    {
    	int ret;
    	u8 val[MAX_BANK];
    
    	chip->regs = &pca957x_regs;
    
    	ret = pca953x_read_regs(chip, chip->regs->output, chip->reg_output);
    	if (ret)
    		goto out;
    	ret = pca953x_read_regs(chip, chip->regs->direction,
    				chip->reg_direction);
    	if (ret)
    		goto out;
    
    	/* set platform specific polarity inversion */
    	if (invert)
    		memset(val, 0xFF, NBANK(chip));
    	else
    		memset(val, 0, NBANK(chip));
    	ret = pca953x_write_regs(chip, PCA957X_INVRT, val);
    	if (ret)
    		goto out;
    
    	/* To enable register 6, 7 to control pull up and pull down */
    	memset(val, 0x02, NBANK(chip));
    	ret = pca953x_write_regs(chip, PCA957X_BKEN, val);
    	if (ret)
    		goto out;
    
    	return 0;
    out:
    	return ret;
    }
    
    static const struct of_device_id pca953x_dt_ids[];
    
    static int pca953x_probe(struct i2c_client *client,
    				   const struct i2c_device_id *i2c_id)
    {
    	struct pca953x_platform_data *pdata;
    	struct pca953x_chip *chip;
    	int irq_base = 0;
    	int ret;
    	u32 invert = 0;
    	struct regulator *reg;
    
    	chip = devm_kzalloc(&client->dev,
    			sizeof(struct pca953x_chip), GFP_KERNEL);
    	if (chip == NULL)
    		return -ENOMEM;
    
    	pdata = dev_get_platdata(&client->dev);
    	if (pdata) {
    		irq_base = pdata->irq_base;
    		chip->gpio_start = pdata->gpio_base;
    		invert = pdata->invert;
    		chip->names = pdata->names;
    	} else {
    		chip->gpio_start = -1;
    		irq_base = 0;
    	}
    
    	chip->client = client;
    
    	reg = devm_regulator_get(&client->dev, "vcc");
    	if (IS_ERR(reg)) {
    		ret = PTR_ERR(reg);
    		if (ret != -EPROBE_DEFER)
    			dev_err(&client->dev, "reg get err: %d\n", ret);
    		return ret;
    	}
    	ret = regulator_enable(reg);
    	if (ret) {
    		dev_err(&client->dev, "reg en err: %d\n", ret);
    		return ret;
    	}
    	chip->regulator = reg;
    
    	if (i2c_id) {
    		chip->driver_data = i2c_id->driver_data;
    	} else {
    		const struct acpi_device_id *acpi_id;
    		const struct of_device_id *match;
    
    		match = of_match_device(pca953x_dt_ids, &client->dev);
    		if (match) {
    			chip->driver_data = (int)(uintptr_t)match->data;
    		} else {
    			acpi_id = acpi_match_device(pca953x_acpi_ids, &client->dev);
    			if (!acpi_id) {
    				ret = -ENODEV;
    				goto err_exit;
    			}
    
    			chip->driver_data = acpi_id->driver_data;
    		}
    	}
    
    	mutex_init(&chip->i2c_lock);
    	/*
    	 * In case we have an i2c-mux controlled by a GPIO provided by an
    	 * expander using the same driver higher on the device tree, read the
    	 * i2c adapter nesting depth and use the retrieved value as lockdep
    	 * subclass for chip->i2c_lock.
    	 *
    	 * REVISIT: This solution is not complete. It protects us from lockdep
    	 * false positives when the expander controlling the i2c-mux is on
    	 * a different level on the device tree, but not when it's on the same
    	 * level on a different branch (in which case the subclass number
    	 * would be the same).
    	 *
    	 * TODO: Once a correct solution is developed, a similar fix should be
    	 * applied to all other i2c-controlled GPIO expanders (and potentially
    	 * regmap-i2c).
    	 */
    	lockdep_set_subclass(&chip->i2c_lock,
    			     i2c_adapter_depth(client->adapter));
    
    	/* initialize cached registers from their original values.
    	 * we can't share this chip with another i2c master.
    	 */
    	pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);
    
    	if (chip->gpio_chip.ngpio <= 8) {
    		chip->write_regs = pca953x_write_regs_8;
    		chip->read_regs = pca953x_read_regs_8;
    	} else if (chip->gpio_chip.ngpio >= 24) {
    		chip->write_regs = pca953x_write_regs_24;
    		chip->read_regs = pca953x_read_regs_24;
    	} else {
    		if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
    			chip->write_regs = pca953x_write_regs_16;
    		else
    			chip->write_regs = pca957x_write_regs_16;
    		chip->read_regs = pca953x_read_regs_16;
    	}
    
    	if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
    		ret = device_pca953x_init(chip, invert);
    	else
    		ret = device_pca957x_init(chip, invert);
    	if (ret)
    		goto err_exit;
    
    	ret = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);
    	if (ret)
    		goto err_exit;
    
    	ret = pca953x_irq_setup(chip, irq_base);
    	if (ret)
    		goto err_exit;
    
    	if (pdata && pdata->setup) {
    		ret = pdata->setup(client, chip->gpio_chip.base,
    				chip->gpio_chip.ngpio, pdata->context);
    		if (ret < 0)
    			dev_warn(&client->dev, "setup failed, %d\n", ret);
    	}
    
    	i2c_set_clientdata(client, chip);
    	return 0;
    
    err_exit:
    	regulator_disable(chip->regulator);
    	return ret;
    }
    
    static int pca953x_remove(struct i2c_client *client)
    {
    	struct pca953x_platform_data *pdata = dev_get_platdata(&client->dev);
    	struct pca953x_chip *chip = i2c_get_clientdata(client);
    	int ret;
    
    	if (pdata && pdata->teardown) {
    		ret = pdata->teardown(client, chip->gpio_chip.base,
    				chip->gpio_chip.ngpio, pdata->context);
    		if (ret < 0)
    			dev_err(&client->dev, "%s failed, %d\n",
    					"teardown", ret);
    	} else {
    		ret = 0;
    	}
    
    	regulator_disable(chip->regulator);
    
    	return ret;
    }
    
    /* convenience to stop overlong match-table lines */
    #define OF_953X(__nrgpio, __int) (void *)(__nrgpio | PCA953X_TYPE | __int)
    #define OF_957X(__nrgpio, __int) (void *)(__nrgpio | PCA957X_TYPE | __int)
    
    static const struct of_device_id pca953x_dt_ids[] = {
    	{ .compatible = "nxp,pca9505", .data = OF_953X(40, PCA_INT), },
    	{ .compatible = "nxp,pca9534", .data = OF_953X( 8, PCA_INT), },
    	{ .compatible = "nxp,pca9535", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "nxp,pca9536", .data = OF_953X( 4, 0), },
    	{ .compatible = "nxp,pca9537", .data = OF_953X( 4, PCA_INT), },
    	{ .compatible = "nxp,pca9538", .data = OF_953X( 8, PCA_INT), },
    	{ .compatible = "nxp,pca9539", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "nxp,pca9554", .data = OF_953X( 8, PCA_INT), },
    	{ .compatible = "nxp,pca9555", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "nxp,pca9556", .data = OF_953X( 8, 0), },
    	{ .compatible = "nxp,pca9557", .data = OF_953X( 8, 0), },
    	{ .compatible = "nxp,pca9574", .data = OF_957X( 8, PCA_INT), },
    	{ .compatible = "nxp,pca9575", .data = OF_957X(16, PCA_INT), },
    	{ .compatible = "nxp,pca9698", .data = OF_953X(40, 0), },
    
    	{ .compatible = "maxim,max7310", .data = OF_953X( 8, 0), },
    	{ .compatible = "maxim,max7312", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "maxim,max7313", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "maxim,max7315", .data = OF_953X( 8, PCA_INT), },
    
    	{ .compatible = "ti,pca6107", .data = OF_953X( 8, PCA_INT), },
    	{ .compatible = "ti,pca9536", .data = OF_953X( 4, 0), },
    	{ .compatible = "ti,tca6408", .data = OF_953X( 8, PCA_INT), },
    	{ .compatible = "ti,tca6416", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "ti,tca6424", .data = OF_953X(24, PCA_INT), },
    
    	{ .compatible = "onsemi,pca9654", .data = OF_953X( 8, PCA_INT), },
    
    	{ .compatible = "exar,xra1202", .data = OF_953X( 8, 0), },
    	{ }
    };
    
    MODULE_DEVICE_TABLE(of, pca953x_dt_ids);
    
    static struct i2c_driver pca953x_driver = {
    	.driver = {
    		.name	= "pca953x",
    		.of_match_table = pca953x_dt_ids,
    		.acpi_match_table = ACPI_PTR(pca953x_acpi_ids),
    	},
    	.probe		= pca953x_probe,
    	.remove		= pca953x_remove,
    	.id_table	= pca953x_id,
    };
    
    static int __init pca953x_init(void)
    {
    	return i2c_add_driver(&pca953x_driver);
    }
    /* register after i2c postcore initcall and before
     * subsys initcalls that may rely on these GPIOs
     */
    subsys_initcall(pca953x_init);
    
    static void __exit pca953x_exit(void)
    {
    	i2c_del_driver(&pca953x_driver);
    }
    module_exit(pca953x_exit);
    
    MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
    MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
    MODULE_LICENSE("GPL");