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![Krzysztof Kozlowski](/assets/img/avatar_default.png)
Common pattern of handling deferred probe can be simplified with dev_err_probe(). Less code and also it prints the error value. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20200829064726.26268-10-krzk@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
244 lines
5.4 KiB
C
244 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* HMC425A and similar Gain Amplifiers
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*
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* Copyright 2020 Analog Devices Inc.
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*/
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/gpio/consumer.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/regulator/consumer.h>
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#include <linux/sysfs.h>
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enum hmc425a_type {
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ID_HMC425A,
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};
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struct hmc425a_chip_info {
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const char *name;
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const struct iio_chan_spec *channels;
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unsigned int num_channels;
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unsigned int num_gpios;
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int gain_min;
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int gain_max;
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int default_gain;
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};
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struct hmc425a_state {
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struct regulator *reg;
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struct mutex lock; /* protect sensor state */
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struct hmc425a_chip_info *chip_info;
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struct gpio_descs *gpios;
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enum hmc425a_type type;
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u32 gain;
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};
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static int hmc425a_write(struct iio_dev *indio_dev, u32 value)
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{
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struct hmc425a_state *st = iio_priv(indio_dev);
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DECLARE_BITMAP(values, BITS_PER_TYPE(value));
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values[0] = value;
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gpiod_set_array_value_cansleep(st->gpios->ndescs, st->gpios->desc,
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NULL, values);
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return 0;
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}
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static int hmc425a_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan, int *val,
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int *val2, long m)
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{
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struct hmc425a_state *st = iio_priv(indio_dev);
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int code, gain = 0;
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int ret;
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mutex_lock(&st->lock);
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switch (m) {
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case IIO_CHAN_INFO_HARDWAREGAIN:
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code = st->gain;
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switch (st->type) {
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case ID_HMC425A:
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gain = ~code * -500;
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break;
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}
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*val = gain / 1000;
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*val2 = (gain % 1000) * 1000;
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ret = IIO_VAL_INT_PLUS_MICRO_DB;
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break;
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default:
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ret = -EINVAL;
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}
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mutex_unlock(&st->lock);
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return ret;
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};
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static int hmc425a_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan, int val,
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int val2, long mask)
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{
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struct hmc425a_state *st = iio_priv(indio_dev);
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struct hmc425a_chip_info *inf = st->chip_info;
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int code = 0, gain;
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int ret;
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if (val < 0)
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gain = (val * 1000) - (val2 / 1000);
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else
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gain = (val * 1000) + (val2 / 1000);
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if (gain > inf->gain_max || gain < inf->gain_min)
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return -EINVAL;
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switch (st->type) {
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case ID_HMC425A:
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code = ~((abs(gain) / 500) & 0x3F);
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break;
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}
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mutex_lock(&st->lock);
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switch (mask) {
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case IIO_CHAN_INFO_HARDWAREGAIN:
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st->gain = code;
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ret = hmc425a_write(indio_dev, st->gain);
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break;
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default:
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ret = -EINVAL;
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}
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mutex_unlock(&st->lock);
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return ret;
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}
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static int hmc425a_write_raw_get_fmt(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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long mask)
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{
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switch (mask) {
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case IIO_CHAN_INFO_HARDWAREGAIN:
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return IIO_VAL_INT_PLUS_MICRO_DB;
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default:
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return -EINVAL;
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}
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}
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static const struct iio_info hmc425a_info = {
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.read_raw = &hmc425a_read_raw,
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.write_raw = &hmc425a_write_raw,
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.write_raw_get_fmt = &hmc425a_write_raw_get_fmt,
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};
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#define HMC425A_CHAN(_channel) \
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{ \
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.type = IIO_VOLTAGE, \
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.output = 1, \
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.indexed = 1, \
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.channel = _channel, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
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}
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static const struct iio_chan_spec hmc425a_channels[] = {
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HMC425A_CHAN(0),
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};
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/* Match table for of_platform binding */
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static const struct of_device_id hmc425a_of_match[] = {
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{ .compatible = "adi,hmc425a", .data = (void *)ID_HMC425A },
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{},
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};
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MODULE_DEVICE_TABLE(of, hmc425a_of_match);
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static void hmc425a_reg_disable(void *data)
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{
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struct hmc425a_state *st = data;
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regulator_disable(st->reg);
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}
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static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
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[ID_HMC425A] = {
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.name = "hmc425a",
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.channels = hmc425a_channels,
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.num_channels = ARRAY_SIZE(hmc425a_channels),
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.num_gpios = 6,
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.gain_min = -31500,
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.gain_max = 0,
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.default_gain = -0x40, /* set default gain -31.5db*/
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},
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};
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static int hmc425a_probe(struct platform_device *pdev)
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{
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struct iio_dev *indio_dev;
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struct hmc425a_state *st;
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int ret;
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indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
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if (!indio_dev)
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return -ENOMEM;
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st = iio_priv(indio_dev);
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st->type = (enum hmc425a_type)of_device_get_match_data(&pdev->dev);
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st->chip_info = &hmc425a_chip_info_tbl[st->type];
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indio_dev->num_channels = st->chip_info->num_channels;
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indio_dev->channels = st->chip_info->channels;
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indio_dev->name = st->chip_info->name;
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st->gain = st->chip_info->default_gain;
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st->gpios = devm_gpiod_get_array(&pdev->dev, "ctrl", GPIOD_OUT_LOW);
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if (IS_ERR(st->gpios))
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return dev_err_probe(&pdev->dev, PTR_ERR(st->gpios),
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"failed to get gpios\n");
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if (st->gpios->ndescs != st->chip_info->num_gpios) {
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dev_err(&pdev->dev, "%d GPIOs needed to operate\n",
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st->chip_info->num_gpios);
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return -ENODEV;
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}
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st->reg = devm_regulator_get(&pdev->dev, "vcc-supply");
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if (IS_ERR(st->reg))
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return PTR_ERR(st->reg);
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ret = regulator_enable(st->reg);
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if (ret)
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return ret;
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ret = devm_add_action_or_reset(&pdev->dev, hmc425a_reg_disable, st);
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if (ret)
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return ret;
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mutex_init(&st->lock);
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indio_dev->info = &hmc425a_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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return devm_iio_device_register(&pdev->dev, indio_dev);
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}
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static struct platform_driver hmc425a_driver = {
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.driver = {
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.name = KBUILD_MODNAME,
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.of_match_table = hmc425a_of_match,
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},
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.probe = hmc425a_probe,
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};
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module_platform_driver(hmc425a_driver);
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MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
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MODULE_DESCRIPTION("Analog Devices HMC425A and similar GPIO control Gain Amplifiers");
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MODULE_LICENSE("GPL v2");
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