From fcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 Mon Sep 17 00:00:00 2001 From: Jonathan Herman Date: Tue, 22 Jan 2013 10:38:37 -0500 Subject: Added missing tegra files. --- drivers/staging/iio/resolver/ad2s120x.c | 177 ++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) create mode 100644 drivers/staging/iio/resolver/ad2s120x.c (limited to 'drivers/staging/iio/resolver') diff --git a/drivers/staging/iio/resolver/ad2s120x.c b/drivers/staging/iio/resolver/ad2s120x.c new file mode 100644 index 00000000000..bed4c725f2d --- /dev/null +++ b/drivers/staging/iio/resolver/ad2s120x.c @@ -0,0 +1,177 @@ +/* + * ad2s120x.c simple support for the ADI Resolver to Digital Converters: AD2S1200/1205 + * + * 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 +#include + +#include "../iio.h" +#include "../sysfs.h" + +#define DRV_NAME "ad2s120x" + +/* input pin sample and rdvel is controlled by driver */ +#define AD2S120X_PN 2 + +/* input clock on serial interface */ +#define AD2S120X_HZ 8192000 +/* clock period in nano second */ +#define AD2S120X_TSCLK (1000000000/AD2S120X_HZ) + +struct ad2s120x_state { + struct mutex lock; + struct spi_device *sdev; + int sample; + int rdvel; + u8 rx[2] ____cacheline_aligned; +}; + +static ssize_t ad2s120x_show_val(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int ret = 0; + ssize_t len = 0; + u16 pos; + s16 vel; + u8 status; + struct ad2s120x_state *st = iio_priv(dev_get_drvdata(dev)); + struct iio_dev_attr *iattr = to_iio_dev_attr(attr); + + mutex_lock(&st->lock); + + gpio_set_value(st->sample, 0); + /* delay (6 * AD2S120X_TSCLK + 20) nano seconds */ + udelay(1); + gpio_set_value(st->sample, 1); + gpio_set_value(st->rdvel, iattr->address); + ret = spi_read(st->sdev, st->rx, 2); + if (ret < 0) + goto error_ret; + status = st->rx[1]; + if (iattr->address) + pos = (((u16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4); + else { + vel = (st->rx[0] & 0x80) ? 0xf000 : 0; + vel |= (((s16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4); + } + len = sprintf(buf, "%d %c%c%c%c ", iattr->address ? pos : vel, + (status & 0x8) ? 'P' : 'V', + (status & 0x4) ? 'd' : '_', + (status & 0x2) ? 'l' : '_', + (status & 0x1) ? '1' : '0'); +error_ret: + /* delay (2 * AD2S120X_TSCLK + 20) ns for sample pulse */ + udelay(1); + mutex_unlock(&st->lock); + + return ret ? ret : len; +} + +static IIO_DEVICE_ATTR(pos, S_IRUGO, ad2s120x_show_val, NULL, 1); +static IIO_DEVICE_ATTR(vel, S_IRUGO, ad2s120x_show_val, NULL, 0); + +static struct attribute *ad2s120x_attributes[] = { + &iio_dev_attr_pos.dev_attr.attr, + &iio_dev_attr_vel.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad2s120x_attribute_group = { + .attrs = ad2s120x_attributes, +}; + +static const struct iio_info ad2s120x_info = { + .attrs = &ad2s120x_attribute_group, + .driver_module = THIS_MODULE, +}; + +static int __devinit ad2s120x_probe(struct spi_device *spi) +{ + struct ad2s120x_state *st; + struct iio_dev *indio_dev; + int pn, ret = 0; + unsigned short *pins = spi->dev.platform_data; + + for (pn = 0; pn < AD2S120X_PN; pn++) + if (gpio_request_one(pins[pn], GPIOF_DIR_OUT, DRV_NAME)) { + pr_err("%s: request gpio pin %d failed\n", + DRV_NAME, pins[pn]); + goto error_ret; + } + indio_dev = iio_allocate_device(sizeof(*st)); + if (indio_dev == NULL) { + ret = -ENOMEM; + goto error_ret; + } + spi_set_drvdata(spi, indio_dev); + st = iio_priv(indio_dev); + mutex_init(&st->lock); + st->sdev = spi; + st->sample = pins[0]; + st->rdvel = pins[1]; + + indio_dev->dev.parent = &spi->dev; + indio_dev->info = &ad2s120x_info; + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_free_dev; + + spi->max_speed_hz = AD2S120X_HZ; + spi->mode = SPI_MODE_3; + spi_setup(spi); + + return 0; + +error_free_dev: + iio_free_device(indio_dev); +error_ret: + for (--pn; pn >= 0; pn--) + gpio_free(pins[pn]); + return ret; +} + +static int __devexit ad2s120x_remove(struct spi_device *spi) +{ + iio_device_unregister(spi_get_drvdata(spi)); + + return 0; +} + +static struct spi_driver ad2s120x_driver = { + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, + .probe = ad2s120x_probe, + .remove = __devexit_p(ad2s120x_remove), +}; + +static __init int ad2s120x_spi_init(void) +{ + return spi_register_driver(&ad2s120x_driver); +} +module_init(ad2s120x_spi_init); + +static __exit void ad2s120x_spi_exit(void) +{ + spi_unregister_driver(&ad2s120x_driver); +} +module_exit(ad2s120x_spi_exit); + +MODULE_AUTHOR("Graff Yang "); +MODULE_DESCRIPTION("Analog Devices AD2S1200/1205 Resolver to Digital SPI driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.2