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206 lines
4.8 KiB
206 lines
4.8 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* ad2s1200.c simple support for the ADI Resolver to Digital Converters: |
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* AD2S1200/1205 |
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* |
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* Copyright (c) 2018-2018 David Veenstra <[email protected]> |
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* Copyright (c) 2010-2010 Analog Devices Inc. |
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*/ |
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#include <linux/bitops.h> |
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#include <linux/delay.h> |
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#include <linux/device.h> |
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#include <linux/gpio/consumer.h> |
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#include <linux/module.h> |
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#include <linux/mod_devicetable.h> |
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#include <linux/mutex.h> |
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#include <linux/spi/spi.h> |
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#include <linux/sysfs.h> |
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#include <linux/types.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#define DRV_NAME "ad2s1200" |
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/* input clock on serial interface */ |
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#define AD2S1200_HZ 8192000 |
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/* clock period in nano second */ |
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#define AD2S1200_TSCLK (1000000000 / AD2S1200_HZ) |
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/** |
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* struct ad2s1200_state - driver instance specific data. |
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* @lock: protects both the GPIO pins and the rx buffer. |
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* @sdev: spi device. |
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* @sample: GPIO pin SAMPLE. |
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* @rdvel: GPIO pin RDVEL. |
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* @rx: buffer for spi transfers. |
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*/ |
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struct ad2s1200_state { |
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struct mutex lock; |
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struct spi_device *sdev; |
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struct gpio_desc *sample; |
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struct gpio_desc *rdvel; |
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__be16 rx ____cacheline_aligned; |
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}; |
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static int ad2s1200_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, |
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int *val2, |
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long m) |
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{ |
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struct ad2s1200_state *st = iio_priv(indio_dev); |
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int ret; |
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switch (m) { |
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case IIO_CHAN_INFO_SCALE: |
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switch (chan->type) { |
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case IIO_ANGL: |
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/* 2 * Pi / (2^12 - 1) ~= 0.001534355 */ |
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*val = 0; |
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*val2 = 1534355; |
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return IIO_VAL_INT_PLUS_NANO; |
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case IIO_ANGL_VEL: |
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/* 2 * Pi ~= 6.283185 */ |
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*val = 6; |
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*val2 = 283185; |
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return IIO_VAL_INT_PLUS_MICRO; |
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default: |
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return -EINVAL; |
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} |
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break; |
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case IIO_CHAN_INFO_RAW: |
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mutex_lock(&st->lock); |
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gpiod_set_value(st->sample, 0); |
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/* delay (6 * AD2S1200_TSCLK + 20) nano seconds */ |
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udelay(1); |
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gpiod_set_value(st->sample, 1); |
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gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL)); |
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ret = spi_read(st->sdev, &st->rx, 2); |
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if (ret < 0) { |
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mutex_unlock(&st->lock); |
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return ret; |
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} |
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switch (chan->type) { |
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case IIO_ANGL: |
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*val = be16_to_cpup(&st->rx) >> 4; |
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break; |
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case IIO_ANGL_VEL: |
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*val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11); |
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break; |
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default: |
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mutex_unlock(&st->lock); |
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return -EINVAL; |
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} |
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/* delay (2 * AD2S1200_TSCLK + 20) ns for sample pulse */ |
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udelay(1); |
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mutex_unlock(&st->lock); |
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return IIO_VAL_INT; |
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default: |
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break; |
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} |
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return -EINVAL; |
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} |
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static const struct iio_chan_spec ad2s1200_channels[] = { |
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{ |
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.type = IIO_ANGL, |
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.indexed = 1, |
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.channel = 0, |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), |
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}, { |
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.type = IIO_ANGL_VEL, |
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.indexed = 1, |
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.channel = 0, |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), |
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} |
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}; |
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static const struct iio_info ad2s1200_info = { |
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.read_raw = ad2s1200_read_raw, |
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}; |
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static int ad2s1200_probe(struct spi_device *spi) |
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{ |
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struct ad2s1200_state *st; |
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struct iio_dev *indio_dev; |
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int ret; |
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); |
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if (!indio_dev) |
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return -ENOMEM; |
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spi_set_drvdata(spi, indio_dev); |
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st = iio_priv(indio_dev); |
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mutex_init(&st->lock); |
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st->sdev = spi; |
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st->sample = devm_gpiod_get(&spi->dev, "adi,sample", GPIOD_OUT_LOW); |
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if (IS_ERR(st->sample)) { |
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dev_err(&spi->dev, "Failed to claim SAMPLE gpio: err=%ld\n", |
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PTR_ERR(st->sample)); |
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return PTR_ERR(st->sample); |
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} |
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st->rdvel = devm_gpiod_get(&spi->dev, "adi,rdvel", GPIOD_OUT_LOW); |
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if (IS_ERR(st->rdvel)) { |
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dev_err(&spi->dev, "Failed to claim RDVEL gpio: err=%ld\n", |
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PTR_ERR(st->rdvel)); |
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return PTR_ERR(st->rdvel); |
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} |
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indio_dev->info = &ad2s1200_info; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->channels = ad2s1200_channels; |
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indio_dev->num_channels = ARRAY_SIZE(ad2s1200_channels); |
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indio_dev->name = spi_get_device_id(spi)->name; |
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spi->max_speed_hz = AD2S1200_HZ; |
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spi->mode = SPI_MODE_3; |
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ret = spi_setup(spi); |
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if (ret < 0) { |
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dev_err(&spi->dev, "spi_setup failed!\n"); |
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return ret; |
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} |
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return devm_iio_device_register(&spi->dev, indio_dev); |
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} |
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static const struct of_device_id ad2s1200_of_match[] = { |
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{ .compatible = "adi,ad2s1200", }, |
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{ .compatible = "adi,ad2s1205", }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, ad2s1200_of_match); |
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static const struct spi_device_id ad2s1200_id[] = { |
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{ "ad2s1200" }, |
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{ "ad2s1205" }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(spi, ad2s1200_id); |
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static struct spi_driver ad2s1200_driver = { |
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.driver = { |
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.name = DRV_NAME, |
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.of_match_table = ad2s1200_of_match, |
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}, |
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.probe = ad2s1200_probe, |
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.id_table = ad2s1200_id, |
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}; |
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module_spi_driver(ad2s1200_driver); |
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MODULE_AUTHOR("David Veenstra <[email protected]>"); |
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MODULE_AUTHOR("Graff Yang <[email protected]>"); |
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MODULE_DESCRIPTION("Analog Devices AD2S1200/1205 Resolver to Digital SPI driver"); |
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MODULE_LICENSE("GPL v2");
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