Staging: IIO: lis3l02dq ring buffer and data ready trigger support (14cd9a73) · Commits · 戴 / test

drivers/staging/iio/accel/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -4,6 +4,7 @@
		obj-$(CONFIG_KXSD9) += kxsd9.o

		lis3l02dq-y := lis3l02dq_core.o
		lis3l02dq-$(CONFIG_IIO_RING_BUFFER) += lis3l02dq_ring.o
		obj-$(CONFIG_LIS3L02DQ) += lis3l02dq.o

		sca3000-y := sca3000_core.o sca3000_ring.o

drivers/staging/iio/accel/lis3l02dq.h

+21 −1

Original line number	Diff line number	Diff line
		@@ -183,6 +183,26 @@ int lis3l02dq_spi_write_reg_8(struct device *dev,
		#define LIS3L02DQ_SCAN_ACC_Y 1
		#define LIS3L02DQ_SCAN_ACC_Z 2


		#ifdef CONFIG_IIO_RING_BUFFER
		/* At the moment triggers are only used for ring buffer
		* filling. This may change!
		*/
		void lis3l02dq_remove_trigger(struct iio_dev *indio_dev);
		int lis3l02dq_probe_trigger(struct iio_dev *indio_dev);

		ssize_t lis3l02dq_read_accel_from_ring(struct device *dev,
		struct device_attribute *attr,
		char *buf);


		int lis3l02dq_configure_ring(struct iio_dev *indio_dev);
		void lis3l02dq_unconfigure_ring(struct iio_dev *indio_dev);

		int lis3l02dq_initialize_ring(struct iio_ring_buffer *ring);
		void lis3l02dq_uninitialize_ring(struct iio_ring_buffer *ring);
		#else /* CONFIG_IIO_RING_BUFFER */

		static inline void lis3l02dq_remove_trigger(struct iio_dev *indio_dev) {};
		static inline int lis3l02dq_probe_trigger(struct iio_dev *indio_dev)
		{
		@@ -208,5 +228,5 @@ static inline int lis3l02dq_initialize_ring(struct iio_ring_buffer *ring)
		return 0;
		};
		static inline void lis3l02dq_uninitialize_ring(struct iio_ring_buffer *ring) {};

		#endif /* CONFIG_IIO_RING_BUFFER */
		#endif /* SPI_LIS3L02DQ_H_ */

drivers/staging/iio/accel/lis3l02dq_ring.c

0 → 100644

+599 −0

Original line number	Diff line number	Diff line
		#include <linux/interrupt.h>
		#include <linux/irq.h>
		#include <linux/gpio.h>
		#include <linux/workqueue.h>
		#include <linux/mutex.h>
		#include <linux/device.h>
		#include <linux/kernel.h>
		#include <linux/spi/spi.h>
		#include <linux/sysfs.h>
		#include <linux/list.h>

		#include "../iio.h"
		#include "../sysfs.h"
		#include "../ring_sw.h"
		#include "accel.h"
		#include "../trigger.h"
		#include "lis3l02dq.h"

		/**
		* combine_8_to_16() utility function to munge to u8s into u16
		**/
		static inline u16 combine_8_to_16(u8 lower, u8 upper)
		{
		u16 _lower = lower;
		u16 _upper = upper;
		return _lower \| (_upper << 8);
		}

		/**
		* lis3l02dq_scan_el_set_state() set whether a scan contains a given channel
		* @scan_el: associtate iio scan element attribute
		* @indio_dev: the device structure
		* @bool: desired state
		*
		* mlock already held when this is called.
		**/
		static int lis3l02dq_scan_el_set_state(struct iio_scan_el *scan_el,
		struct iio_dev *indio_dev,
		bool state)
		{
		u8 t, mask;
		int ret;

		ret = lis3l02dq_spi_read_reg_8(&indio_dev->dev,
		LIS3L02DQ_REG_CTRL_1_ADDR,
		&t);
		if (ret)
		goto error_ret;
		switch (scan_el->label) {
		case LIS3L02DQ_REG_OUT_X_L_ADDR:
		mask = LIS3L02DQ_REG_CTRL_1_AXES_X_ENABLE;
		break;
		case LIS3L02DQ_REG_OUT_Y_L_ADDR:
		mask = LIS3L02DQ_REG_CTRL_1_AXES_Y_ENABLE;
		break;
		case LIS3L02DQ_REG_OUT_Z_L_ADDR:
		mask = LIS3L02DQ_REG_CTRL_1_AXES_Z_ENABLE;
		break;
		default:
		ret = -EINVAL;
		goto error_ret;
		}

		if (!(mask & t) == state) {
		if (state)
		t \|= mask;
		else
		t &= ~mask;
		ret = lis3l02dq_spi_write_reg_8(&indio_dev->dev,
		LIS3L02DQ_REG_CTRL_1_ADDR,
		&t);
		}
		error_ret:
		return ret;

		}
		static IIO_SCAN_EL_C(accel_x, LIS3L02DQ_SCAN_ACC_X, IIO_SIGNED(16),
		LIS3L02DQ_REG_OUT_X_L_ADDR,
		&lis3l02dq_scan_el_set_state);
		static IIO_SCAN_EL_C(accel_y, LIS3L02DQ_SCAN_ACC_Y, IIO_SIGNED(16),
		LIS3L02DQ_REG_OUT_Y_L_ADDR,
		&lis3l02dq_scan_el_set_state);
		static IIO_SCAN_EL_C(accel_z, LIS3L02DQ_SCAN_ACC_Z, IIO_SIGNED(16),
		LIS3L02DQ_REG_OUT_Z_L_ADDR,
		&lis3l02dq_scan_el_set_state);
		static IIO_SCAN_EL_TIMESTAMP;

		static struct attribute *lis3l02dq_scan_el_attrs[] = {
		&iio_scan_el_accel_x.dev_attr.attr,
		&iio_scan_el_accel_y.dev_attr.attr,
		&iio_scan_el_accel_z.dev_attr.attr,
		&iio_scan_el_timestamp.dev_attr.attr,
		NULL,
		};

		static struct attribute_group lis3l02dq_scan_el_group = {
		.attrs = lis3l02dq_scan_el_attrs,
		.name = "scan_elements",
		};

		/**
		* lis3l02dq_poll_func_th() top half interrupt handler called by trigger
		* @private_data: iio_dev
		**/
		static void lis3l02dq_poll_func_th(struct iio_dev *indio_dev)
		{
		struct lis3l02dq_state *st = iio_dev_get_devdata(indio_dev);
		st->last_timestamp = indio_dev->trig->timestamp;
		schedule_work(&st->work_trigger_to_ring);
		/* Indicate that this interrupt is being handled */

		/* Technically this is trigger related, but without this
		* handler running there is currently now way for the interrupt
		* to clear.
		*/
		st->inter = 1;
		}

		/**
		* lis3l02dq_data_rdy_trig_poll() the event handler for the data rdy trig
		**/
		static int lis3l02dq_data_rdy_trig_poll(struct iio_dev *dev_info,
		int index,
		s64 timestamp,
		int no_test)
		{
		struct lis3l02dq_state *st = iio_dev_get_devdata(dev_info);
		struct iio_trigger *trig = st->trig;

		trig->timestamp = timestamp;
		iio_trigger_poll(trig);

		return IRQ_HANDLED;
		}

		/* This is an event as it is a response to a physical interrupt */
		IIO_EVENT_SH(data_rdy_trig, &lis3l02dq_data_rdy_trig_poll);

		/**
		* lis3l02dq_read_accel_from_ring() individual acceleration read from ring
		**/
		ssize_t lis3l02dq_read_accel_from_ring(struct device *dev,
		struct device_attribute *attr,
		char *buf)
		{
		struct iio_scan_el *el = NULL;
		int ret, len = 0, i = 0;
		struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
		struct iio_dev *dev_info = dev_get_drvdata(dev);
		s16 *data;

		while (dev_info->scan_el_attrs->attrs[i]) {
		el = to_iio_scan_el((struct device_attribute *)
		(dev_info->scan_el_attrs->attrs[i]));
		/* label is in fact the address */
		if (el->label == this_attr->address)
		break;
		i++;
		}
		if (!dev_info->scan_el_attrs->attrs[i]) {
		ret = -EINVAL;
		goto error_ret;
		}
		/* If this element is in the scan mask */
		ret = iio_scan_mask_query(dev_info, el->number);
		if (ret < 0)
		goto error_ret;
		if (ret) {
		data = kmalloc(dev_info->ring->access.get_bpd(dev_info->ring),
		GFP_KERNEL);
		if (data == NULL)
		return -ENOMEM;
		ret = dev_info->ring->access.read_last(dev_info->ring,
		(u8 *)data);
		if (ret)
		goto error_free_data;
		} else {
		ret = -EINVAL;
		goto error_ret;
		}
		len = iio_scan_mask_count_to_right(dev_info, el->number);
		if (len < 0) {
		ret = len;
		goto error_free_data;
		}
		len = sprintf(buf, "ring %d\n", data[len]);
		error_free_data:
		kfree(data);
		error_ret:
		return ret ? ret : len;

		}

		static const u8 read_all_tx_array[] =
		{
		LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_X_L_ADDR), 0,
		LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_X_H_ADDR), 0,
		LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Y_L_ADDR), 0,
		LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Y_H_ADDR), 0,
		LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Z_L_ADDR), 0,
		LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Z_H_ADDR), 0,
		};

		/**
		* lis3l02dq_read_all() Reads all channels currently selected
		* @st: device specific state
		* @rx_array: (dma capable) recieve array, must be at least
		* 4*number of channels
		**/
		int lis3l02dq_read_all(struct lis3l02dq_state st, u8 rx_array)
		{
		struct spi_transfer *xfers;
		struct spi_message msg;
		int ret, i, j = 0;

		xfers = kzalloc((st->indio_dev->scan_count) * 2
		* sizeof(*xfers), GFP_KERNEL);
		if (!xfers)
		return -ENOMEM;

		mutex_lock(&st->buf_lock);

		for (i = 0; i < ARRAY_SIZE(read_all_tx_array)/4; i++) {
		if (st->indio_dev->scan_mask & (1 << i)) {
		/* lower byte */
		xfers[j].tx_buf = st->tx + 2*j;
		st->tx[2j] = read_all_tx_array[i4];
		st->tx[2*j + 1] = 0;
		if (rx_array)
		xfers[j].rx_buf = rx_array + j*2;
		xfers[j].bits_per_word = 8;
		xfers[j].len = 2;
		xfers[j].cs_change = 1;
		j++;

		/* upper byte */
		xfers[j].tx_buf = st->tx + 2*j;
		st->tx[2j] = read_all_tx_array[i4 + 2];
		st->tx[2*j + 1] = 0;
		if (rx_array)
		xfers[j].rx_buf = rx_array + j*2;
		xfers[j].bits_per_word = 8;
		xfers[j].len = 2;
		xfers[j].cs_change = 1;
		j++;
		}
		}
		/* After these are transmitted, the rx_buff should have
		* values in alternate bytes
		*/
		spi_message_init(&msg);
		for (j = 0; j < st->indio_dev->scan_count * 2; j++)
		spi_message_add_tail(&xfers[j], &msg);

		ret = spi_sync(st->us, &msg);
		mutex_unlock(&st->buf_lock);
		kfree(xfers);

		return ret;
		}


		/* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
		* specific to be rolled into the core.
		*/
		static void lis3l02dq_trigger_bh_to_ring(struct work_struct *work_s)
		{
		struct lis3l02dq_state *st
		= container_of(work_s, struct lis3l02dq_state,
		work_trigger_to_ring);

		u8 *rx_array;
		int i = 0;
		u16 *data;
		size_t datasize = st->indio_dev
		->ring->access.get_bpd(st->indio_dev->ring);

		data = kmalloc(datasize , GFP_KERNEL);
		if (data == NULL) {
		dev_err(&st->us->dev, "memory alloc failed in ring bh");
		return;
		}
		/* Due to interleaved nature of transmission this buffer must be
		* twice the number of bytes, or 4 times the number of channels
		*/
		rx_array = kmalloc(4 * (st->indio_dev->scan_count), GFP_KERNEL);
		if (rx_array == NULL) {
		dev_err(&st->us->dev, "memory alloc failed in ring bh");
		return;
		}

		/* whilst trigger specific, if this read does nto occur the data
		ready interrupt will not be cleared. Need to add a mechanism
		to provide a dummy read function if this is not triggering on
		the data ready function but something else is.
		*/
		st->inter = 0;

		if (st->indio_dev->scan_count)
		if (lis3l02dq_read_all(st, rx_array) >= 0)
		for (; i < st->indio_dev->scan_count; i++)
		data[i] = combine_8_to_16(rx_array[i*4+1],
		rx_array[i*4+3]);
		/* Guaranteed to be aligned with 8 byte boundary */
		if (st->indio_dev->scan_timestamp)
		((s64 )(data + ((i + 3)/4)*4)) = st->last_timestamp;

		st->indio_dev->ring->access.store_to(st->indio_dev->ring,
		(u8 *)data,
		st->last_timestamp);

		iio_trigger_notify_done(st->indio_dev->trig);
		kfree(rx_array);
		kfree(data);

		return;
		}
		/* in these circumstances is it better to go with unaligned packing and
		* deal with the cost?*/
		static int lis3l02dq_data_rdy_ring_preenable(struct iio_dev *indio_dev)
		{
		size_t size;
		/* Check if there are any scan elements enabled, if not fail*/
		if (!(indio_dev->scan_count \|\| indio_dev->scan_timestamp))
		return -EINVAL;

		if (indio_dev->ring->access.set_bpd) {
		if (indio_dev->scan_timestamp)
		if (indio_dev->scan_count) /* Timestamp and data */
		size = 2*sizeof(s64);
		else /* Timestamp only */
		size = sizeof(s64);
		else /* Data only */
		size = indio_dev->scan_count*sizeof(s16);
		indio_dev->ring->access.set_bpd(indio_dev->ring, size);
		}

		return 0;
		}

		static int lis3l02dq_data_rdy_ring_postenable(struct iio_dev *indio_dev)
		{
		return indio_dev->trig
		? iio_trigger_attach_poll_func(indio_dev->trig,
		indio_dev->pollfunc)
		: 0;
		}

		static int lis3l02dq_data_rdy_ring_predisable(struct iio_dev *indio_dev)
		{
		return indio_dev->trig
		? iio_trigger_dettach_poll_func(indio_dev->trig,
		indio_dev->pollfunc)
		: 0;
		}


		/* Caller responsible for locking as necessary. */
		static int __lis3l02dq_write_data_ready_config(struct device *dev,
		struct
		iio_event_handler_list *list,
		bool state)
		{
		int ret;
		u8 valold;
		bool currentlyset;
		struct iio_dev *indio_dev = dev_get_drvdata(dev);

		/* Get the current event mask register */
		ret = lis3l02dq_spi_read_reg_8(dev,
		LIS3L02DQ_REG_CTRL_2_ADDR,
		&valold);
		if (ret)
		goto error_ret;
		/* Find out if data ready is already on */
		currentlyset
		= valold & LIS3L02DQ_REG_CTRL_2_ENABLE_DATA_READY_GENERATION;

		/* Disable requested */
		if (!state && currentlyset) {

		valold &= ~LIS3L02DQ_REG_CTRL_2_ENABLE_DATA_READY_GENERATION;
		/* The double write is to overcome a hardware bug?*/
		ret = lis3l02dq_spi_write_reg_8(dev,
		LIS3L02DQ_REG_CTRL_2_ADDR,
		&valold);
		if (ret)
		goto error_ret;
		ret = lis3l02dq_spi_write_reg_8(dev,
		LIS3L02DQ_REG_CTRL_2_ADDR,
		&valold);
		if (ret)
		goto error_ret;

		iio_remove_event_from_list(list,
		&indio_dev->interrupts[0]
		->ev_list);

		/* Enable requested */
		} else if (state && !currentlyset) {
		/* if not set, enable requested */
		valold \|= LIS3L02DQ_REG_CTRL_2_ENABLE_DATA_READY_GENERATION;
		iio_add_event_to_list(list, &indio_dev->interrupts[0]->ev_list);
		ret = lis3l02dq_spi_write_reg_8(dev,
		LIS3L02DQ_REG_CTRL_2_ADDR,
		&valold);
		if (ret)
		goto error_ret;
		}

		return 0;
		error_ret:
		return ret;
		}

		/**
		* lis3l02dq_data_rdy_trigger_set_state() set datardy interrupt state
		*
		* If disabling the interrupt also does a final read to ensure it is clear.
		* This is only important in some cases where the scan enable elements are
		* switched before the ring is reenabled.
		**/
		static int lis3l02dq_data_rdy_trigger_set_state(struct iio_trigger *trig,
		bool state)
		{
		struct lis3l02dq_state *st = trig->private_data;
		int ret = 0;
		u8 t;
		__lis3l02dq_write_data_ready_config(&st->indio_dev->dev,
		&iio_event_data_rdy_trig,
		state);
		if (state == false) {
		/* possible quirk with handler currently worked around
		by ensuring the work queue is empty */
		flush_scheduled_work();
		/* Clear any outstanding ready events */
		ret = lis3l02dq_read_all(st, NULL);
		}
		lis3l02dq_spi_read_reg_8(&st->indio_dev->dev,
		LIS3L02DQ_REG_WAKE_UP_SRC_ADDR,
		&t);
		return ret;
		}
		DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);

		static struct attribute *lis3l02dq_trigger_attrs[] = {
		&dev_attr_name.attr,
		NULL,
		};

		static const struct attribute_group lis3l02dq_trigger_attr_group = {
		.attrs = lis3l02dq_trigger_attrs,
		};

		/**
		* lis3l02dq_trig_try_reen() try renabling irq for data rdy trigger
		* @trig: the datardy trigger
		*
		* As the trigger may occur on any data element being updated it is
		* really rather likely to occur during the read from the previous
		* trigger event. The only way to discover if this has occured on
		* boards not supporting level interrupts is to take a look at the line.
		* If it is indicating another interrupt and we don't seem to have a
		* handler looking at it, then we need to notify the core that we need
		* to tell the triggering core to try reading all these again.
		**/
		static int lis3l02dq_trig_try_reen(struct iio_trigger *trig)
		{
		struct lis3l02dq_state *st = trig->private_data;
		enable_irq(st->us->irq);
		/* If gpio still high (or high again) */
		if (gpio_get_value(irq_to_gpio(st->us->irq)))
		if (st->inter == 0) {
		/* already interrupt handler dealing with it */
		disable_irq_nosync(st->us->irq);
		if (st->inter == 1) {
		/* interrupt handler snuck in between test
		* and disable */
		enable_irq(st->us->irq);
		return 0;
		}
		return -EAGAIN;
		}
		/* irq reenabled so success! */
		return 0;
		}

		int lis3l02dq_probe_trigger(struct iio_dev *indio_dev)
		{
		int ret;
		struct lis3l02dq_state *state = indio_dev->dev_data;

		state->trig = iio_allocate_trigger();
		state->trig->name = kmalloc(IIO_TRIGGER_NAME_LENGTH, GFP_KERNEL);
		if (!state->trig->name) {
		ret = -ENOMEM;
		goto error_free_trig;
		}
		snprintf((char *)state->trig->name,
		IIO_TRIGGER_NAME_LENGTH,
		"lis3l02dq-dev%d", indio_dev->id);
		state->trig->dev.parent = &state->us->dev;
		state->trig->owner = THIS_MODULE;
		state->trig->private_data = state;
		state->trig->set_trigger_state = &lis3l02dq_data_rdy_trigger_set_state;
		state->trig->try_reenable = &lis3l02dq_trig_try_reen;
		state->trig->control_attrs = &lis3l02dq_trigger_attr_group;
		ret = iio_trigger_register(state->trig);
		if (ret)
		goto error_free_trig_name;

		return 0;

		error_free_trig_name:
		kfree(state->trig->name);
		error_free_trig:
		iio_free_trigger(state->trig);

		return ret;
		}

		void lis3l02dq_remove_trigger(struct iio_dev *indio_dev)
		{
		struct lis3l02dq_state *state = indio_dev->dev_data;

		iio_trigger_unregister(state->trig);
		kfree(state->trig->name);
		iio_free_trigger(state->trig);
		}

		void lis3l02dq_unconfigure_ring(struct iio_dev *indio_dev)
		{
		kfree(indio_dev->pollfunc);
		iio_sw_rb_free(indio_dev->ring);
		}

		int lis3l02dq_configure_ring(struct iio_dev *indio_dev)
		{
		int ret = 0;
		struct lis3l02dq_state *st = indio_dev->dev_data;
		struct iio_ring_buffer *ring;
		INIT_WORK(&st->work_trigger_to_ring, lis3l02dq_trigger_bh_to_ring);
		/* Set default scan mode */

		iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
		iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
		iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
		indio_dev->scan_timestamp = true;

		indio_dev->scan_el_attrs = &lis3l02dq_scan_el_group;

		ring = iio_sw_rb_allocate(indio_dev);
		if (!ring) {
		ret = -ENOMEM;
		return ret;
		}
		indio_dev->ring = ring;
		/* Effectively select the ring buffer implementation */
		iio_ring_sw_register_funcs(&ring->access);
		ring->preenable = &lis3l02dq_data_rdy_ring_preenable;
		ring->postenable = &lis3l02dq_data_rdy_ring_postenable;
		ring->predisable = &lis3l02dq_data_rdy_ring_predisable;
		ring->owner = THIS_MODULE;

		indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
		if (indio_dev->pollfunc == NULL) {
		ret = -ENOMEM;
		goto error_iio_sw_rb_free;;
		}
		indio_dev->pollfunc->poll_func_main = &lis3l02dq_poll_func_th;
		indio_dev->pollfunc->private_data = indio_dev;
		indio_dev->modes \|= INDIO_RING_TRIGGERED;
		return 0;

		error_iio_sw_rb_free:
		iio_sw_rb_free(indio_dev->ring);
		return ret;
		}

		int lis3l02dq_initialize_ring(struct iio_ring_buffer *ring)
		{
		return iio_ring_buffer_register(ring);
		}

		void lis3l02dq_uninitialize_ring(struct iio_ring_buffer *ring)
		{
		iio_ring_buffer_unregister(ring);
		}


		int lis3l02dq_set_ring_length(struct iio_dev *indio_dev, int length)
		{
		/* Set sensible defaults for the ring buffer */
		if (indio_dev->ring->access.set_length)
		return indio_dev->ring->access.set_length(indio_dev->ring, 500);
		return 0;
		}

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