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+/*
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+ * pca9539.c - 16-bit I/O port with interrupt and reset
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+ *
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+ * Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
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+ * Copyright (C) 2007 Marvell International Ltd.
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+ *
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+ * Derived from drivers/i2c/chips/pca9539.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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+
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+#include <linux/module.h>
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+#include <linux/init.h>
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+#include <linux/i2c.h>
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+#include <linux/i2c/pca9539.h>
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+
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+#include <asm/gpio.h>
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+
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+
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+#define NR_PCA9539_GPIOS 16
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+
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+#define PCA9539_INPUT 0
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+#define PCA9539_OUTPUT 2
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+#define PCA9539_INVERT 4
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+#define PCA9539_DIRECTION 6
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+
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+struct pca9539_chip {
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+ unsigned gpio_start;
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+ uint16_t reg_output;
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+ uint16_t reg_direction;
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+
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+ struct i2c_client *client;
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+ struct gpio_chip gpio_chip;
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+};
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+
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+/* NOTE: we can't currently rely on fault codes to come from SMBus
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+ * calls, so we map all errors to EIO here and return zero otherwise.
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+ */
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+static int pca9539_write_reg(struct pca9539_chip *chip, int reg, uint16_t val)
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+{
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+ if (i2c_smbus_write_word_data(chip->client, reg, val) < 0)
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+ return -EIO;
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+ else
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+ return 0;
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+}
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+
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+static int pca9539_read_reg(struct pca9539_chip *chip, int reg, uint16_t *val)
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+{
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+ int ret;
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+
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+ ret = i2c_smbus_read_word_data(chip->client, reg);
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+ if (ret < 0) {
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+ dev_err(&chip->client->dev, "failed reading register\n");
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+ return -EIO;
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+ }
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+
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+ *val = (uint16_t)ret;
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+ return 0;
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+}
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+
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+static int pca9539_gpio_direction_input(struct gpio_chip *gc, unsigned off)
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+{
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+ struct pca9539_chip *chip;
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+ uint16_t reg_val;
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+ int ret;
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+
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+ chip = container_of(gc, struct pca9539_chip, gpio_chip);
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+
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+ reg_val = chip->reg_direction | (1u << off);
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+ ret = pca9539_write_reg(chip, PCA9539_DIRECTION, reg_val);
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+ if (ret)
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+ return ret;
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+
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+ chip->reg_direction = reg_val;
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+ return 0;
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+}
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+
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+static int pca9539_gpio_direction_output(struct gpio_chip *gc,
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+ unsigned off, int val)
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+{
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+ struct pca9539_chip *chip;
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+ uint16_t reg_val;
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+ int ret;
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+
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+ chip = container_of(gc, struct pca9539_chip, gpio_chip);
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+
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+ /* set output level */
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+ if (val)
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+ reg_val = chip->reg_output | (1u << off);
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+ else
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+ reg_val = chip->reg_output & ~(1u << off);
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+
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+ ret = pca9539_write_reg(chip, PCA9539_OUTPUT, reg_val);
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+ if (ret)
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+ return ret;
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+
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+ chip->reg_output = reg_val;
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+
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+ /* then direction */
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+ reg_val = chip->reg_direction & ~(1u << off);
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+ ret = pca9539_write_reg(chip, PCA9539_DIRECTION, reg_val);
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+ if (ret)
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+ return ret;
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+
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+ chip->reg_direction = reg_val;
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+ return 0;
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+}
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+
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+static int pca9539_gpio_get_value(struct gpio_chip *gc, unsigned off)
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+{
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+ struct pca9539_chip *chip;
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+ uint16_t reg_val;
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+ int ret;
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+
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+ chip = container_of(gc, struct pca9539_chip, gpio_chip);
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+
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+ ret = pca9539_read_reg(chip, PCA9539_INPUT, ®_val);
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+ if (ret < 0) {
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+ /* NOTE: diagnostic already emitted; that's all we should
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+ * do unless gpio_*_value_cansleep() calls become different
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+ * from their nonsleeping siblings (and report faults).
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+ */
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+ return 0;
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+ }
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+
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+ return (reg_val & (1u << off)) ? 1 : 0;
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+}
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+
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+static void pca9539_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
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+{
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+ struct pca9539_chip *chip;
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+ uint16_t reg_val;
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+ int ret;
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+
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+ chip = container_of(gc, struct pca9539_chip, gpio_chip);
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+
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+ if (val)
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+ reg_val = chip->reg_output | (1u << off);
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+ else
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+ reg_val = chip->reg_output & ~(1u << off);
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+
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+ ret = pca9539_write_reg(chip, PCA9539_OUTPUT, reg_val);
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+ if (ret)
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+ return;
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+
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+ chip->reg_output = reg_val;
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+}
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+
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+static int pca9539_init_gpio(struct pca9539_chip *chip)
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+{
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+ struct gpio_chip *gc;
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+
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+ gc = &chip->gpio_chip;
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+
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+ gc->direction_input = pca9539_gpio_direction_input;
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+ gc->direction_output = pca9539_gpio_direction_output;
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+ gc->get = pca9539_gpio_get_value;
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+ gc->set = pca9539_gpio_set_value;
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+
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+ gc->base = chip->gpio_start;
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+ gc->ngpio = NR_PCA9539_GPIOS;
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+ gc->label = "pca9539";
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+
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+ return gpiochip_add(gc);
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+}
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+
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+static int __devinit pca9539_probe(struct i2c_client *client)
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+{
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+ struct pca9539_platform_data *pdata;
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+ struct pca9539_chip *chip;
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+ int ret;
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+
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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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+
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+ chip = kzalloc(sizeof(struct pca9539_chip), GFP_KERNEL);
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+ if (chip == NULL)
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+ return -ENOMEM;
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+
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+ chip->client = client;
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+
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+ chip->gpio_start = pdata->gpio_base;
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+
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+ /* initialize cached registers from their original values.
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+ * we can't share this chip with another i2c master.
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+ */
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+ ret = pca9539_read_reg(chip, PCA9539_OUTPUT, &chip->reg_output);
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+ if (ret)
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+ goto out_failed;
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+
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+ ret = pca9539_read_reg(chip, PCA9539_DIRECTION, &chip->reg_direction);
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+ if (ret)
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+ goto out_failed;
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+
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+ /* set platform specific polarity inversion */
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+ ret = pca9539_write_reg(chip, PCA9539_INVERT, pdata->invert);
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+ if (ret)
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+ goto out_failed;
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+
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+ ret = pca9539_init_gpio(chip);
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+ if (ret)
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+ goto out_failed;
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+
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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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+
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+ i2c_set_clientdata(client, chip);
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+ return 0;
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+
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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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+
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+static int pca9539_remove(struct i2c_client *client)
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+{
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+ struct pca9539_platform_data *pdata = client->dev.platform_data;
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+ struct pca9539_chip *chip = i2c_get_clientdata(client);
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+ int ret = 0;
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+
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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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+
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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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+
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+ kfree(chip);
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+ return 0;
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+}
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+
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+static struct i2c_driver pca9539_driver = {
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+ .driver = {
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+ .name = "pca9539",
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+ },
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+ .probe = pca9539_probe,
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+ .remove = pca9539_remove,
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+};
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+
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+static int __init pca9539_init(void)
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+{
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+ return i2c_add_driver(&pca9539_driver);
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+}
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+module_init(pca9539_init);
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+
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+static void __exit pca9539_exit(void)
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+{
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+ i2c_del_driver(&pca9539_driver);
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+}
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+module_exit(pca9539_exit);
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+
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+MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
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+MODULE_DESCRIPTION("GPIO expander driver for PCA9539");
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+MODULE_LICENSE("GPL");
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