alistair23-linux/drivers/staging/iio/resolver/ad2s90.c
Linus Torvalds 75f5db39ff spi: Updates for v4.4
Quite a lot of activity in SPI this cycle, almost all of it in drivers
 with a few minor improvements and tweaks in the core.
 
  - Updates to pxa2xx to support Intel Broxton and multiple chip selects.
  - Support for big endian in the bcm63xx driver.
  - Multiple slave support for the mt8173
  - New driver for the auxiliary SPI controller in bcm2835 SoCs.
  - Support for Layerscale SoCs in the Freescale DSPI driver.
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Merge tag 'spi-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "Quite a lot of activity in SPI this cycle, almost all of it in drivers
  with a few minor improvements and tweaks in the core.

   - Updates to pxa2xx to support Intel Broxton and multiple chip selects.
   - Support for big endian in the bcm63xx driver.
   - Multiple slave support for the mt8173
   - New driver for the auxiliary SPI controller in bcm2835 SoCs.
   - Support for Layerscale SoCs in the Freescale DSPI driver"

* tag 'spi-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (87 commits)
  spi: pxa2xx: Rework self-initiated platform data creation for non-ACPI
  spi: pxa2xx: Add support for Intel Broxton
  spi: pxa2xx: Detect number of enabled Intel LPSS SPI chip select signals
  spi: pxa2xx: Add output control for multiple Intel LPSS chip selects
  spi: pxa2xx: Use LPSS prefix for defines that are Intel LPSS specific
  spi: Add DSPI support for layerscape family
  spi: ti-qspi: improve ->remove() callback
  spi/spi-xilinx: Fix race condition on last word read
  spi: Drop owner assignment from spi_drivers
  spi: Add THIS_MODULE to spi_driver in SPI core
  spi: Setup the master controller driver before setting the chipselect
  spi: dw: replace magic constant by DW_SPI_DR
  spi: mediatek: mt8173 spi multiple devices support
  spi: mediatek: handle controller_data in mtk_spi_setup
  spi: mediatek: remove mtk_spi_config
  spi: mediatek: Update document devicetree bindings to support multiple devices
  spi: fix kernel-doc warnings about missing return desc in spi.c
  spi: fix kernel-doc warnings about missing return desc in spi.h
  spi: pxa2xx: Align a few defines
  spi: pxa2xx: Save other reg_cs_ctrl bits when configuring chip select
  ...
2015-11-05 13:15:12 -08:00

112 lines
2.5 KiB
C

/*
* ad2s90.c simple support for the ADI Resolver to Digital Converters: AD2S90
*
* Copyright (c) 2010-2010 Analog Devices Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
struct ad2s90_state {
struct mutex lock;
struct spi_device *sdev;
u8 rx[2] ____cacheline_aligned;
};
static int ad2s90_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
int ret;
struct ad2s90_state *st = iio_priv(indio_dev);
mutex_lock(&st->lock);
ret = spi_read(st->sdev, st->rx, 2);
if (ret)
goto error_ret;
*val = (((u16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4);
error_ret:
mutex_unlock(&st->lock);
return IIO_VAL_INT;
}
static const struct iio_info ad2s90_info = {
.read_raw = &ad2s90_read_raw,
.driver_module = THIS_MODULE,
};
static const struct iio_chan_spec ad2s90_chan = {
.type = IIO_ANGL,
.indexed = 1,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
};
static int ad2s90_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct ad2s90_state *st;
int ret = 0;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
spi_set_drvdata(spi, indio_dev);
mutex_init(&st->lock);
st->sdev = spi;
indio_dev->dev.parent = &spi->dev;
indio_dev->info = &ad2s90_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = &ad2s90_chan;
indio_dev->num_channels = 1;
indio_dev->name = spi_get_device_id(spi)->name;
ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
if (ret)
return ret;
/* need 600ns between CS and the first falling edge of SCLK */
spi->max_speed_hz = 830000;
spi->mode = SPI_MODE_3;
spi_setup(spi);
return 0;
}
static const struct spi_device_id ad2s90_id[] = {
{ "ad2s90" },
{}
};
MODULE_DEVICE_TABLE(spi, ad2s90_id);
static struct spi_driver ad2s90_driver = {
.driver = {
.name = "ad2s90",
},
.probe = ad2s90_probe,
.id_table = ad2s90_id,
};
module_spi_driver(ad2s90_driver);
MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
MODULE_DESCRIPTION("Analog Devices AD2S90 Resolver to Digital SPI driver");
MODULE_LICENSE("GPL v2");