/drivers/staging/iio/accel/lis3l02dq_ring.c
C | 514 lines | 379 code | 58 blank | 77 comment | 47 complexity | ba2de05258ae8ea7fd50f58eef015c1e MD5 | raw file
- #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 <linux/slab.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, 0, IIO_SIGNED(16),
- LIS3L02DQ_REG_OUT_X_L_ADDR,
- &lis3l02dq_scan_el_set_state);
- static IIO_SCAN_EL_C(accel_y, 1, IIO_SIGNED(16),
- LIS3L02DQ_REG_OUT_Y_L_ADDR,
- &lis3l02dq_scan_el_set_state);
- static IIO_SCAN_EL_C(accel_z, 2, IIO_SIGNED(16),
- LIS3L02DQ_REG_OUT_Z_L_ADDR,
- &lis3l02dq_scan_el_set_state);
- static IIO_SCAN_EL_TIMESTAMP(3);
- 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, s64 time)
- {
- struct iio_sw_ring_helper_state *h
- = iio_dev_get_devdata(indio_dev);
- struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
- /* in this case we need to slightly extend the helper function */
- iio_sw_poll_func_th(indio_dev, time);
- /* 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 *indio_dev,
- int index,
- s64 timestamp,
- int no_test)
- {
- struct iio_sw_ring_helper_state *h
- = iio_dev_get_devdata(indio_dev);
- struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
- iio_trigger_poll(st->trig, timestamp);
- 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
- **/
- static 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->help.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->help.indio_dev->scan_mask & (1 << i)) {
- /* lower byte */
- xfers[j].tx_buf = st->tx + 2*j;
- st->tx[2*j] = read_all_tx_array[i*4];
- 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[2*j] = read_all_tx_array[i*4 + 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->help.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;
- }
- static void lis3l02dq_trigger_bh_to_ring(struct work_struct *work_s)
- {
- struct iio_sw_ring_helper_state *h
- = container_of(work_s, struct iio_sw_ring_helper_state,
- work_trigger_to_ring);
- struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
- st->inter = 0;
- iio_sw_trigger_bh_to_ring(work_s);
- }
- static int lis3l02dq_get_ring_element(struct iio_sw_ring_helper_state *h,
- u8 *buf)
- {
- int ret, i;
- u8 *rx_array ;
- s16 *data = (s16 *)buf;
- rx_array = kzalloc(4 * (h->indio_dev->scan_count), GFP_KERNEL);
- if (rx_array == NULL)
- return -ENOMEM;
- ret = lis3l02dq_read_all(lis3l02dq_h_to_s(h), rx_array);
- if (ret < 0)
- return ret;
- for (i = 0; i < h->indio_dev->scan_count; i++)
- data[i] = combine_8_to_16(rx_array[i*4+1],
- rx_array[i*4+3]);
- kfree(rx_array);
- return i*sizeof(data[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->help.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->help.indio_dev->dev,
- LIS3L02DQ_REG_WAKE_UP_SRC_ADDR,
- &t);
- return ret;
- }
- static 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();
- if (!state->trig)
- return -ENOMEM;
- state->trig->name = kasprintf(GFP_KERNEL,
- "lis3l02dq-dev%d",
- indio_dev->id);
- if (!state->trig->name) {
- ret = -ENOMEM;
- goto error_free_trig;
- }
- 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;
- struct iio_sw_ring_helper_state *h = iio_dev_get_devdata(indio_dev);
- INIT_WORK(&h->work_trigger_to_ring, lis3l02dq_trigger_bh_to_ring);
- /* Set default scan mode */
- h->get_ring_element = &lis3l02dq_get_ring_element;
- 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;
- indio_dev->ring = iio_sw_rb_allocate(indio_dev);
- if (!indio_dev->ring)
- return -ENOMEM;
- /* Effectively select the ring buffer implementation */
- iio_ring_sw_register_funcs(&indio_dev->ring->access);
- indio_dev->ring->bpe = 2;
- indio_dev->ring->preenable = &iio_sw_ring_preenable;
- indio_dev->ring->postenable = &iio_triggered_ring_postenable;
- indio_dev->ring->predisable = &iio_triggered_ring_predisable;
- indio_dev->ring->owner = THIS_MODULE;
- ret = iio_alloc_pollfunc(indio_dev, NULL, &lis3l02dq_poll_func_th);
- if (ret)
- goto error_iio_sw_rb_free;;
- indio_dev->modes |= INDIO_RING_TRIGGERED;
- return 0;
- error_iio_sw_rb_free:
- iio_sw_rb_free(indio_dev->ring);
- return ret;
- }