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gpio: max732x driver
This adds a driver supporting a family of I2C port expanders from Maxim, which includes the MAX7319 and MAX7320-7327 chips. [dbrownell@users.sourceforge.net: minor fixes] Signed-off-by: Jack Ren <jack.ren@marvell.com> Signed-off-by: Eric Miao <eric.miao@marvell.com> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Eric Miao
Linus Torvalds
parent
7444a72eff
commit
bbcd6d543d
@ -67,6 +67,25 @@ config GPIO_SYSFS
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comment "I2C GPIO expanders:"
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config GPIO_MAX732X
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tristate "MAX7319, MAX7320-7327 I2C Port Expanders"
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depends on I2C
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help
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Say yes here to support the MAX7319, MAX7320-7327 series of I2C
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Port Expanders. Each IO port on these chips has a fixed role of
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Input (designated by 'I'), Push-Pull Output ('O'), or Open-Drain
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Input and Output (designed by 'P'). The combinations are listed
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below:
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8 bits: max7319 (8I), max7320 (8O), max7321 (8P),
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max7322 (4I4O), max7323 (4P4O)
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16 bits: max7324 (8I8O), max7325 (8P8O),
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max7326 (4I12O), max7327 (4P12O)
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Board setup code must specify the model to use, and the start
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number for these GPIOs.
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config GPIO_PCA953X
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tristate "PCA953x, PCA955x, and MAX7310 I/O ports"
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depends on I2C
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@ -5,6 +5,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG
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obj-$(CONFIG_GPIOLIB) += gpiolib.o
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obj-$(CONFIG_GPIO_MAX7301) += max7301.o
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obj-$(CONFIG_GPIO_MAX732X) += max732x.o
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obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o
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obj-$(CONFIG_GPIO_PCA953X) += pca953x.o
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obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o
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385
drivers/gpio/max732x.c
Normal file
385
drivers/gpio/max732x.c
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@ -0,0 +1,385 @@
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/*
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* max732x.c - I2C Port Expander with 8/16 I/O
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*
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* Copyright (C) 2007 Marvell International Ltd.
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* Copyright (C) 2008 Jack Ren <jack.ren@marvell.com>
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* Copyright (C) 2008 Eric Miao <eric.miao@marvell.com>
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*
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* Derived from drivers/gpio/pca953x.c
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/gpio.h>
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#include <linux/i2c.h>
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#include <linux/i2c/max732x.h>
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/*
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* Each port of MAX732x (including MAX7319) falls into one of the
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* following three types:
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*
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* - Push Pull Output
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* - Input
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* - Open Drain I/O
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*
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* designated by 'O', 'I' and 'P' individually according to MAXIM's
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* datasheets.
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*
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* There are two groups of I/O ports, each group usually includes
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* up to 8 I/O ports, and is accessed by a specific I2C address:
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*
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* - Group A : by I2C address 0b'110xxxx
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* - Group B : by I2C address 0b'101xxxx
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*
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* where 'xxxx' is decided by the connections of pin AD2/AD0. The
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* address used also affects the initial state of output signals.
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*
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* Within each group of ports, there are five known combinations of
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* I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
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* the detailed organization of these ports.
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*
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* GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
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* and GPIOs from GROUP_A are numbered before those from GROUP_B
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* (if there are two groups).
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*
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* NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
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* they are not supported by this driver.
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*/
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#define PORT_NONE 0x0 /* '/' No Port */
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#define PORT_OUTPUT 0x1 /* 'O' Push-Pull, Output Only */
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#define PORT_INPUT 0x2 /* 'I' Input Only */
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#define PORT_OPENDRAIN 0x3 /* 'P' Open-Drain, I/O */
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#define IO_4I4O 0x5AA5 /* O7 O6 I5 I4 I3 I2 O1 O0 */
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#define IO_4P4O 0x5FF5 /* O7 O6 P5 P4 P3 P2 O1 O0 */
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#define IO_8I 0xAAAA /* I7 I6 I5 I4 I3 I2 I1 I0 */
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#define IO_8P 0xFFFF /* P7 P6 P5 P4 P3 P2 P1 P0 */
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#define IO_8O 0x5555 /* O7 O6 O5 O4 O3 O2 O1 O0 */
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#define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */
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#define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */
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static const struct i2c_device_id max732x_id[] = {
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{ "max7319", GROUP_A(IO_8I) },
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{ "max7320", GROUP_B(IO_8O) },
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{ "max7321", GROUP_A(IO_8P) },
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{ "max7322", GROUP_A(IO_4I4O) },
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{ "max7323", GROUP_A(IO_4P4O) },
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{ "max7324", GROUP_A(IO_8I) | GROUP_B(IO_8O) },
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{ "max7325", GROUP_A(IO_8P) | GROUP_B(IO_8O) },
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{ "max7326", GROUP_A(IO_4I4O) | GROUP_B(IO_8O) },
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{ "max7327", GROUP_A(IO_4P4O) | GROUP_B(IO_8O) },
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{ },
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};
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MODULE_DEVICE_TABLE(i2c, max732x_id);
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struct max732x_chip {
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struct gpio_chip gpio_chip;
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struct i2c_client *client; /* "main" client */
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struct i2c_client *client_dummy;
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struct i2c_client *client_group_a;
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struct i2c_client *client_group_b;
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unsigned int mask_group_a;
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unsigned int dir_input;
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unsigned int dir_output;
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struct mutex lock;
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uint8_t reg_out[2];
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};
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static int max732x_write(struct max732x_chip *chip, int group_a, uint8_t val)
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{
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struct i2c_client *client;
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int ret;
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client = group_a ? chip->client_group_a : chip->client_group_b;
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ret = i2c_smbus_write_byte(client, val);
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if (ret < 0) {
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dev_err(&client->dev, "failed writing\n");
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return ret;
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}
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return 0;
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}
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static int max732x_read(struct max732x_chip *chip, int group_a, uint8_t *val)
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{
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struct i2c_client *client;
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int ret;
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client = group_a ? chip->client_group_a : chip->client_group_b;
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ret = i2c_smbus_read_byte(client);
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if (ret < 0) {
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dev_err(&client->dev, "failed reading\n");
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return ret;
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}
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*val = (uint8_t)ret;
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return 0;
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}
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static inline int is_group_a(struct max732x_chip *chip, unsigned off)
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{
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return (1u << off) & chip->mask_group_a;
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}
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static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
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{
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struct max732x_chip *chip;
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uint8_t reg_val;
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int ret;
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chip = container_of(gc, struct max732x_chip, gpio_chip);
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ret = max732x_read(chip, is_group_a(chip, off), ®_val);
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if (ret < 0)
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return 0;
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return reg_val & (1u << (off & 0x7));
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}
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static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
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{
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struct max732x_chip *chip;
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uint8_t reg_out, mask = 1u << (off & 0x7);
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int ret;
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chip = container_of(gc, struct max732x_chip, gpio_chip);
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mutex_lock(&chip->lock);
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reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
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reg_out = (val) ? reg_out | mask : reg_out & ~mask;
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ret = max732x_write(chip, is_group_a(chip, off), reg_out);
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if (ret < 0)
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goto out;
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/* update the shadow register then */
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if (off > 7)
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chip->reg_out[1] = reg_out;
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else
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chip->reg_out[0] = reg_out;
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out:
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mutex_unlock(&chip->lock);
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}
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static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
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{
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struct max732x_chip *chip;
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unsigned int mask = 1u << off;
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chip = container_of(gc, struct max732x_chip, gpio_chip);
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if ((mask & chip->dir_input) == 0) {
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dev_dbg(&chip->client->dev, "%s port %d is output only\n",
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chip->client->name, off);
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return -EACCES;
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}
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return 0;
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}
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static int max732x_gpio_direction_output(struct gpio_chip *gc,
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unsigned off, int val)
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{
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struct max732x_chip *chip;
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unsigned int mask = 1u << off;
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chip = container_of(gc, struct max732x_chip, gpio_chip);
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if ((mask & chip->dir_output) == 0) {
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dev_dbg(&chip->client->dev, "%s port %d is input only\n",
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chip->client->name, off);
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return -EACCES;
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}
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max732x_gpio_set_value(gc, off, val);
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return 0;
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}
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static int __devinit max732x_setup_gpio(struct max732x_chip *chip,
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const struct i2c_device_id *id,
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unsigned gpio_start)
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{
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struct gpio_chip *gc = &chip->gpio_chip;
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uint32_t id_data = id->driver_data;
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int i, port = 0;
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for (i = 0; i < 16; i++, id_data >>= 2) {
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unsigned int mask = 1 << port;
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switch (id_data & 0x3) {
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case PORT_OUTPUT:
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chip->dir_output |= mask;
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break;
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case PORT_INPUT:
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chip->dir_input |= mask;
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break;
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case PORT_OPENDRAIN:
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chip->dir_output |= mask;
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chip->dir_input |= mask;
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break;
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default:
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continue;
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}
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if (i < 8)
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chip->mask_group_a |= mask;
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port++;
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}
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if (chip->dir_input)
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gc->direction_input = max732x_gpio_direction_input;
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if (chip->dir_output) {
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gc->direction_output = max732x_gpio_direction_output;
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gc->set = max732x_gpio_set_value;
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}
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gc->get = max732x_gpio_get_value;
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gc->can_sleep = 1;
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gc->base = gpio_start;
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gc->ngpio = port;
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gc->label = chip->client->name;
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gc->owner = THIS_MODULE;
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return port;
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}
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static int __devinit max732x_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct max732x_platform_data *pdata;
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struct max732x_chip *chip;
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struct i2c_client *c;
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uint16_t addr_a, addr_b;
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int ret, nr_port;
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pdata = client->dev.platform_data;
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if (pdata == NULL)
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return -ENODEV;
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chip = kzalloc(sizeof(struct max732x_chip), GFP_KERNEL);
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if (chip == NULL)
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return -ENOMEM;
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chip->client = client;
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nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
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addr_a = (client->addr & 0x0f) | 0x60;
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addr_b = (client->addr & 0x0f) | 0x50;
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switch (client->addr & 0x70) {
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case 0x60:
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chip->client_group_a = client;
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if (nr_port > 7) {
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c = i2c_new_dummy(client->adapter, addr_b);
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chip->client_group_b = chip->client_dummy = c;
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}
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break;
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case 0x50:
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chip->client_group_b = client;
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if (nr_port > 7) {
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c = i2c_new_dummy(client->adapter, addr_a);
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chip->client_group_a = chip->client_dummy = c;
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}
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break;
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default:
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dev_err(&client->dev, "invalid I2C address specified %02x\n",
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client->addr);
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ret = -EINVAL;
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goto out_failed;
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}
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mutex_init(&chip->lock);
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max732x_read(chip, is_group_a(chip, 0), &chip->reg_out[0]);
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if (nr_port > 7)
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max732x_read(chip, is_group_a(chip, 8), &chip->reg_out[1]);
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ret = gpiochip_add(&chip->gpio_chip);
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if (ret)
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goto out_failed;
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if (pdata->setup) {
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ret = pdata->setup(client, chip->gpio_chip.base,
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chip->gpio_chip.ngpio, pdata->context);
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if (ret < 0)
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dev_warn(&client->dev, "setup failed, %d\n", ret);
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}
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i2c_set_clientdata(client, chip);
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return 0;
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out_failed:
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kfree(chip);
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return ret;
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}
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static int __devexit max732x_remove(struct i2c_client *client)
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{
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struct max732x_platform_data *pdata = client->dev.platform_data;
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struct max732x_chip *chip = i2c_get_clientdata(client);
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int ret;
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if (pdata->teardown) {
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ret = pdata->teardown(client, chip->gpio_chip.base,
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chip->gpio_chip.ngpio, pdata->context);
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if (ret < 0) {
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dev_err(&client->dev, "%s failed, %d\n",
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"teardown", ret);
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return ret;
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}
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}
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ret = gpiochip_remove(&chip->gpio_chip);
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if (ret) {
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dev_err(&client->dev, "%s failed, %d\n",
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"gpiochip_remove()", ret);
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return ret;
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}
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/* unregister any dummy i2c_client */
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if (chip->client_dummy)
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i2c_unregister_device(chip->client_dummy);
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kfree(chip);
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return 0;
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}
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static struct i2c_driver max732x_driver = {
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.driver = {
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.name = "max732x",
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.owner = THIS_MODULE,
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},
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.probe = max732x_probe,
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.remove = __devexit_p(max732x_remove),
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.id_table = max732x_id,
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};
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static int __init max732x_init(void)
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{
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return i2c_add_driver(&max732x_driver);
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}
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module_init(max732x_init);
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static void __exit max732x_exit(void)
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{
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i2c_del_driver(&max732x_driver);
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}
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module_exit(max732x_exit);
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MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
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MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
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MODULE_LICENSE("GPL");
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19
include/linux/i2c/max732x.h
Normal file
19
include/linux/i2c/max732x.h
Normal file
@ -0,0 +1,19 @@
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#ifndef __LINUX_I2C_MAX732X_H
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#define __LINUX_I2C_MAX732X_H
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/* platform data for the MAX732x 8/16-bit I/O expander driver */
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struct max732x_platform_data {
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/* number of the first GPIO */
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unsigned gpio_base;
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void *context; /* param to setup/teardown */
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int (*setup)(struct i2c_client *client,
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unsigned gpio, unsigned ngpio,
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void *context);
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int (*teardown)(struct i2c_client *client,
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unsigned gpio, unsigned ngpio,
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void *context);
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};
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#endif /* __LINUX_I2C_MAX732X_H */
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