diff options
Diffstat (limited to 'drivers/staging/iio/accel/sca3000_ring.c')
-rw-r--r-- | drivers/staging/iio/accel/sca3000_ring.c | 350 |
1 files changed, 0 insertions, 350 deletions
diff --git a/drivers/staging/iio/accel/sca3000_ring.c b/drivers/staging/iio/accel/sca3000_ring.c deleted file mode 100644 index d1cb9b9cf22b..000000000000 --- a/drivers/staging/iio/accel/sca3000_ring.c +++ /dev/null @@ -1,350 +0,0 @@ -/* - * sca3000_ring.c -- support VTI sca3000 series accelerometers via SPI - * - * 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. - * - * Copyright (c) 2009 Jonathan Cameron <jic23@kernel.org> - * - */ - -#include <linux/interrupt.h> -#include <linux/fs.h> -#include <linux/slab.h> -#include <linux/kernel.h> -#include <linux/spi/spi.h> -#include <linux/sysfs.h> -#include <linux/sched.h> -#include <linux/poll.h> - -#include <linux/iio/iio.h> -#include <linux/iio/sysfs.h> -#include <linux/iio/buffer.h> -#include "../ring_hw.h" -#include "sca3000.h" - -/* RFC / future work - * - * The internal ring buffer doesn't actually change what it holds depending - * on which signals are enabled etc, merely whether you can read them. - * As such the scan mode selection is somewhat different than for a software - * ring buffer and changing it actually covers any data already in the buffer. - * Currently scan elements aren't configured so it doesn't matter. - */ - -static int sca3000_read_data(struct sca3000_state *st, - u8 reg_address_high, - u8 **rx_p, - int len) -{ - int ret; - struct spi_transfer xfer[2] = { - { - .len = 1, - .tx_buf = st->tx, - }, { - .len = len, - } - }; - *rx_p = kmalloc(len, GFP_KERNEL); - if (!*rx_p) { - ret = -ENOMEM; - goto error_ret; - } - xfer[1].rx_buf = *rx_p; - st->tx[0] = SCA3000_READ_REG(reg_address_high); - ret = spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer)); - if (ret) { - dev_err(get_device(&st->us->dev), "problem reading register"); - goto error_free_rx; - } - - return 0; -error_free_rx: - kfree(*rx_p); -error_ret: - return ret; -} - -/** - * sca3000_read_first_n_hw_rb() - main ring access, pulls data from ring - * @r: the ring - * @count: number of samples to try and pull - * @data: output the actual samples pulled from the hw ring - * - * Currently does not provide timestamps. As the hardware doesn't add them they - * can only be inferred approximately from ring buffer events such as 50% full - * and knowledge of when buffer was last emptied. This is left to userspace. - **/ -static int sca3000_read_first_n_hw_rb(struct iio_buffer *r, - size_t count, char __user *buf) -{ - struct iio_hw_buffer *hw_ring = iio_to_hw_buf(r); - struct iio_dev *indio_dev = hw_ring->private; - struct sca3000_state *st = iio_priv(indio_dev); - u8 *rx; - int ret, i, num_available, num_read = 0; - int bytes_per_sample = 1; - - if (st->bpse == 11) - bytes_per_sample = 2; - - mutex_lock(&st->lock); - if (count % bytes_per_sample) { - ret = -EINVAL; - goto error_ret; - } - - ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_BUF_COUNT, 1); - if (ret) - goto error_ret; - num_available = st->rx[0]; - /* - * num_available is the total number of samples available - * i.e. number of time points * number of channels. - */ - if (count > num_available * bytes_per_sample) - num_read = num_available * bytes_per_sample; - else - num_read = count; - - ret = sca3000_read_data(st, - SCA3000_REG_ADDR_RING_OUT, - &rx, num_read); - if (ret) - goto error_ret; - - for (i = 0; i < num_read / sizeof(u16); i++) - *(((u16 *)rx) + i) = be16_to_cpup((__be16 *)rx + i); - - if (copy_to_user(buf, rx, num_read)) - ret = -EFAULT; - kfree(rx); - r->stufftoread = 0; -error_ret: - mutex_unlock(&st->lock); - - return ret ? ret : num_read; -} - -static size_t sca3000_ring_buf_data_available(struct iio_buffer *r) -{ - return r->stufftoread ? r->watermark : 0; -} - -/** - * sca3000_query_ring_int() is the hardware ring status interrupt enabled - **/ -static ssize_t sca3000_query_ring_int(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); - int ret, val; - struct iio_dev *indio_dev = dev_to_iio_dev(dev); - struct sca3000_state *st = iio_priv(indio_dev); - - mutex_lock(&st->lock); - ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1); - val = st->rx[0]; - mutex_unlock(&st->lock); - if (ret) - return ret; - - return sprintf(buf, "%d\n", !!(val & this_attr->address)); -} - -/** - * sca3000_set_ring_int() set state of ring status interrupt - **/ -static ssize_t sca3000_set_ring_int(struct device *dev, - struct device_attribute *attr, - const char *buf, - size_t len) -{ - struct iio_dev *indio_dev = dev_to_iio_dev(dev); - struct sca3000_state *st = iio_priv(indio_dev); - struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); - u8 val; - int ret; - - mutex_lock(&st->lock); - ret = kstrtou8(buf, 10, &val); - if (ret) - goto error_ret; - ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1); - if (ret) - goto error_ret; - if (val) - ret = sca3000_write_reg(st, - SCA3000_REG_ADDR_INT_MASK, - st->rx[0] | this_attr->address); - else - ret = sca3000_write_reg(st, - SCA3000_REG_ADDR_INT_MASK, - st->rx[0] & ~this_attr->address); -error_ret: - mutex_unlock(&st->lock); - - return ret ? ret : len; -} - -static IIO_DEVICE_ATTR(50_percent, S_IRUGO | S_IWUSR, - sca3000_query_ring_int, - sca3000_set_ring_int, - SCA3000_INT_MASK_RING_HALF); - -static IIO_DEVICE_ATTR(75_percent, S_IRUGO | S_IWUSR, - sca3000_query_ring_int, - sca3000_set_ring_int, - SCA3000_INT_MASK_RING_THREE_QUARTER); - -static ssize_t sca3000_show_buffer_scale(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - struct iio_dev *indio_dev = dev_to_iio_dev(dev); - struct sca3000_state *st = iio_priv(indio_dev); - - return sprintf(buf, "0.%06d\n", 4 * st->info->scale); -} - -static IIO_DEVICE_ATTR(in_accel_scale, - S_IRUGO, - sca3000_show_buffer_scale, - NULL, - 0); - -/* - * Ring buffer attributes - * This device is a bit unusual in that the sampling frequency and bpse - * only apply to the ring buffer. At all times full rate and accuracy - * is available via direct reading from registers. - */ -static const struct attribute *sca3000_ring_attributes[] = { - &iio_dev_attr_50_percent.dev_attr.attr, - &iio_dev_attr_75_percent.dev_attr.attr, - &iio_dev_attr_in_accel_scale.dev_attr.attr, - NULL, -}; - -static struct iio_buffer *sca3000_rb_allocate(struct iio_dev *indio_dev) -{ - struct iio_buffer *buf; - struct iio_hw_buffer *ring; - - ring = kzalloc(sizeof(*ring), GFP_KERNEL); - if (!ring) - return NULL; - - ring->private = indio_dev; - buf = &ring->buf; - buf->stufftoread = 0; - buf->length = 64; - buf->attrs = sca3000_ring_attributes; - iio_buffer_init(buf); - - return buf; -} - -static void sca3000_ring_release(struct iio_buffer *r) -{ - kfree(iio_to_hw_buf(r)); -} - -static const struct iio_buffer_access_funcs sca3000_ring_access_funcs = { - .read_first_n = &sca3000_read_first_n_hw_rb, - .data_available = sca3000_ring_buf_data_available, - .release = sca3000_ring_release, - - .modes = INDIO_BUFFER_HARDWARE, -}; - -int sca3000_configure_ring(struct iio_dev *indio_dev) -{ - struct iio_buffer *buffer; - - buffer = sca3000_rb_allocate(indio_dev); - if (!buffer) - return -ENOMEM; - indio_dev->modes |= INDIO_BUFFER_HARDWARE; - - indio_dev->buffer->access = &sca3000_ring_access_funcs; - - iio_device_attach_buffer(indio_dev, buffer); - - return 0; -} - -void sca3000_unconfigure_ring(struct iio_dev *indio_dev) -{ - iio_buffer_put(indio_dev->buffer); -} - -static inline -int __sca3000_hw_ring_state_set(struct iio_dev *indio_dev, bool state) -{ - struct sca3000_state *st = iio_priv(indio_dev); - int ret; - - mutex_lock(&st->lock); - ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); - if (ret) - goto error_ret; - if (state) { - dev_info(&indio_dev->dev, "supposedly enabling ring buffer\n"); - ret = sca3000_write_reg(st, - SCA3000_REG_ADDR_MODE, - (st->rx[0] | SCA3000_RING_BUF_ENABLE)); - } else - ret = sca3000_write_reg(st, - SCA3000_REG_ADDR_MODE, - (st->rx[0] & ~SCA3000_RING_BUF_ENABLE)); -error_ret: - mutex_unlock(&st->lock); - - return ret; -} - -/** - * sca3000_hw_ring_preenable() hw ring buffer preenable function - * - * Very simple enable function as the chip will allows normal reads - * during ring buffer operation so as long as it is indeed running - * before we notify the core, the precise ordering does not matter. - **/ -static int sca3000_hw_ring_preenable(struct iio_dev *indio_dev) -{ - return __sca3000_hw_ring_state_set(indio_dev, 1); -} - -static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev) -{ - return __sca3000_hw_ring_state_set(indio_dev, 0); -} - -static const struct iio_buffer_setup_ops sca3000_ring_setup_ops = { - .preenable = &sca3000_hw_ring_preenable, - .postdisable = &sca3000_hw_ring_postdisable, -}; - -void sca3000_register_ring_funcs(struct iio_dev *indio_dev) -{ - indio_dev->setup_ops = &sca3000_ring_setup_ops; -} - -/** - * sca3000_ring_int_process() ring specific interrupt handling. - * - * This is only split from the main interrupt handler so as to - * reduce the amount of code if the ring buffer is not enabled. - **/ -void sca3000_ring_int_process(u8 val, struct iio_buffer *ring) -{ - if (val & (SCA3000_INT_STATUS_THREE_QUARTERS | - SCA3000_INT_STATUS_HALF)) { - ring->stufftoread = true; - wake_up_interruptible(&ring->pollq); - } -} |