From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Mike Frysinger To: linux-iio@vger.kernel.org, Jonathan Cameron Cc: device-drivers-devel@blackfin.uclinux.org, Graf Yang , Michael Hennerich Subject: [PATCH 34/36] staging: iio: resolver: new driver for AD2S90 devices Date: Tue, 26 Oct 2010 14:17:44 -0400 Message-Id: <1288117066-18055-35-git-send-email-vapier@gentoo.org> In-Reply-To: <1288117066-18055-1-git-send-email-vapier@gentoo.org> References: <1288117066-18055-1-git-send-email-vapier@gentoo.org> List-ID: From: Graf Yang This also kicks off the new resolver subsection. Signed-off-by: Graf Yang Signed-off-by: Michael Hennerich Acked-by: Jonathan Cameron Signed-off-by: Mike Frysinger --- drivers/staging/iio/Kconfig | 1 + drivers/staging/iio/Makefile | 1 + drivers/staging/iio/resolver/Kconfig | 11 +++ drivers/staging/iio/resolver/Makefile | 5 + drivers/staging/iio/resolver/ad2s90.c | 159 +++++++++++++++++++++++++++++++++ 5 files changed, 177 insertions(+), 0 deletions(-) create mode 100644 drivers/staging/iio/resolver/Kconfig create mode 100644 drivers/staging/iio/resolver/Makefile create mode 100644 drivers/staging/iio/resolver/ad2s90.c diff --git a/drivers/staging/iio/Kconfig b/drivers/staging/iio/Kconfig index ffe8912..e2ac07d 100644 --- a/drivers/staging/iio/Kconfig +++ b/drivers/staging/iio/Kconfig @@ -50,6 +50,7 @@ source "drivers/staging/iio/imu/Kconfig" source "drivers/staging/iio/light/Kconfig" source "drivers/staging/iio/magnetometer/Kconfig" source "drivers/staging/iio/meter/Kconfig" +source "drivers/staging/iio/resolver/Kconfig" source "drivers/staging/iio/trigger/Kconfig" endif # IIO diff --git a/drivers/staging/iio/Makefile b/drivers/staging/iio/Makefile index 5b449a1..f9b5fb2 100644 --- a/drivers/staging/iio/Makefile +++ b/drivers/staging/iio/Makefile @@ -19,4 +19,5 @@ obj-y += imu/ obj-y += light/ obj-y += magnetometer/ obj-y += meter/ +obj-y += resolver/ obj-y += trigger/ diff --git a/drivers/staging/iio/resolver/Kconfig b/drivers/staging/iio/resolver/Kconfig new file mode 100644 index 0000000..05b15a9 --- /dev/null +++ b/drivers/staging/iio/resolver/Kconfig @@ -0,0 +1,11 @@ +# +# Resolver/Synchro drivers +# +comment "Resolver to digital converters" + +config AD2S90 + tristate "Analog Devices ad2s90 driver" + depends on SPI + help + Say yes here to build support for Analog Devices spi resolver + to digital converters, ad2s90, provides direct access via sysfs. diff --git a/drivers/staging/iio/resolver/Makefile b/drivers/staging/iio/resolver/Makefile new file mode 100644 index 0000000..067fa70 --- /dev/null +++ b/drivers/staging/iio/resolver/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for Resolver/Synchro drivers +# + +obj-$(CONFIG_AD2S90) += ad2s90.o diff --git a/drivers/staging/iio/resolver/ad2s90.c b/drivers/staging/iio/resolver/ad2s90.c new file mode 100644 index 0000000..4143535 --- /dev/null +++ b/drivers/staging/iio/resolver/ad2s90.c @@ -0,0 +1,159 @@ +/* + * 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 +#include +#include +#include +#include +#include + +#include "../iio.h" +#include "../sysfs.h" + +#define DRV_NAME "ad2s90" + +struct ad2s90_state { + struct mutex lock; + struct iio_dev *idev; + struct spi_device *sdev; + u8 rx[2]; + u8 tx[2]; +}; + +static ssize_t ad2s90_show_angular(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct spi_message msg; + struct spi_transfer xfer; + int ret; + ssize_t len = 0; + u16 val; + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s90_state *st = idev->dev_data; + + xfer.len = 1; + xfer.tx_buf = st->tx; + xfer.rx_buf = st->rx; + mutex_lock(&st->lock); + + spi_message_init(&msg); + spi_message_add_tail(&xfer, &msg); + ret = spi_sync(st->sdev, &msg); + if (ret) + goto error_ret; + val = (((u16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4); + len = sprintf(buf, "%d\n", val); +error_ret: + mutex_unlock(&st->lock); + + return ret ? ret : len; +} + +#define IIO_DEV_ATTR_SIMPLE_RESOLVER(_show) \ + IIO_DEVICE_ATTR(angular, S_IRUGO, _show, NULL, 0) + +static IIO_CONST_ATTR(description, + "Low Cost, Complete 12-Bit Resolver-to-Digital Converter"); +static IIO_DEV_ATTR_SIMPLE_RESOLVER(ad2s90_show_angular); + +static struct attribute *ad2s90_attributes[] = { + &iio_const_attr_description.dev_attr.attr, + &iio_dev_attr_angular.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad2s90_attribute_group = { + .name = DRV_NAME, + .attrs = ad2s90_attributes, +}; + +static int __devinit ad2s90_probe(struct spi_device *spi) +{ + struct ad2s90_state *st; + int ret = 0; + + st = kzalloc(sizeof(*st), GFP_KERNEL); + if (st == NULL) { + ret = -ENOMEM; + goto error_ret; + } + spi_set_drvdata(spi, st); + + mutex_init(&st->lock); + st->sdev = spi; + + st->idev = iio_allocate_device(); + if (st->idev == NULL) { + ret = -ENOMEM; + goto error_free_st; + } + st->idev->dev.parent = &spi->dev; + st->idev->num_interrupt_lines = 0; + st->idev->event_attrs = NULL; + + st->idev->attrs = &ad2s90_attribute_group; + st->idev->dev_data = (void *)(st); + st->idev->driver_module = THIS_MODULE; + st->idev->modes = INDIO_DIRECT_MODE; + + ret = iio_device_register(st->idev); + if (ret) + goto error_free_dev; + + /* 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; + +error_free_dev: + iio_free_device(st->idev); +error_free_st: + kfree(st); +error_ret: + return ret; +} + +static int __devexit ad2s90_remove(struct spi_device *spi) +{ + struct ad2s90_state *st = spi_get_drvdata(spi); + + iio_device_unregister(st->idev); + kfree(st); + + return 0; +} + +static struct spi_driver ad2s90_driver = { + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, + .probe = ad2s90_probe, + .remove = __devexit_p(ad2s90_remove), +}; + +static __init int ad2s90_spi_init(void) +{ + return spi_register_driver(&ad2s90_driver); +} +module_init(ad2s90_spi_init); + +static __exit void ad2s90_spi_exit(void) +{ + spi_unregister_driver(&ad2s90_driver); +} +module_exit(ad2s90_spi_exit); + +MODULE_AUTHOR("Graff Yang "); +MODULE_DESCRIPTION("Analog Devices AD2S90 Resolver to Digital SPI driver"); +MODULE_LICENSE("GPL v2"); -- 1.7.3.2