staging: iio: lis3l02dq: use iio_sw_ring_helper_state and funcs
authorJonathan Cameron <jic23@cam.ac.uk>
Sun, 11 Jul 2010 15:39:19 +0000 (16:39 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 22 Jul 2010 18:38:29 +0000 (11:38 -0700)
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/staging/iio/accel/lis3l02dq.h
drivers/staging/iio/accel/lis3l02dq_core.c
drivers/staging/iio/accel/lis3l02dq_ring.c

index 6de172e..44669ee 100644 (file)
@@ -148,30 +148,29 @@ Form of high byte dependant on justification set in ctrl reg */
 #define LIS3L02DQ_MAX_RX 12
 /**
  * struct lis3l02dq_state - device instance specific data
+ * @helper:            data and func pointer allowing generic functions
  * @us:                        actual spi_device
- * @work_trigger_to_ring: bh for triggered event handling
  * @work_thresh:       bh for threshold events
  * @inter:             used to check if new interrupt has been triggered
- * @last_timestamp:    passing timestamp from th to bh of interrupt handler
- * @indio_dev:         industrial I/O device structure
  * @trig:              data ready trigger registered with iio
  * @tx:                        transmit buffer
  * @rx:                        recieve buffer
  * @buf_lock:          mutex to protect tx and rx
  **/
 struct lis3l02dq_state {
+       struct iio_sw_ring_helper_state help;
        struct spi_device               *us;
-       struct work_struct              work_trigger_to_ring;
        struct work_struct              work_thresh;
        bool                            inter;
-       s64                             last_timestamp;
-       struct iio_dev                  *indio_dev;
        struct iio_trigger              *trig;
        u8                              *tx;
        u8                              *rx;
        struct mutex                    buf_lock;
 };
 
+#define lis3l02dq_h_to_s(_h)                           \
+       container_of(_h, struct lis3l02dq_state, help)
+
 int lis3l02dq_spi_read_reg_8(struct device *dev,
                             u8 reg_address,
                             u8 *val);
index f86ffb8..b04f498 100644 (file)
@@ -28,6 +28,8 @@
 #include "../iio.h"
 #include "../sysfs.h"
 #include "../ring_generic.h"
+#include "../ring_sw.h"
+
 #include "accel.h"
 
 #include "lis3l02dq.h"
@@ -48,7 +50,9 @@ int lis3l02dq_spi_read_reg_8(struct device *dev, u8 reg_address, u8 *val)
        int ret;
        struct spi_message msg;
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
-       struct lis3l02dq_state *st = iio_dev_get_devdata(indio_dev);
+       struct iio_sw_ring_helper_state *h = iio_dev_get_devdata(indio_dev);
+       struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
+
        struct spi_transfer xfer = {
                .tx_buf = st->tx,
                .rx_buf = st->rx,
@@ -83,7 +87,9 @@ int lis3l02dq_spi_write_reg_8(struct device *dev,
        int ret;
        struct spi_message msg;
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
-       struct lis3l02dq_state *st = iio_dev_get_devdata(indio_dev);
+       struct iio_sw_ring_helper_state *h
+               = iio_dev_get_devdata(indio_dev);
+       struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
        struct spi_transfer xfer = {
                .tx_buf = st->tx,
                .bits_per_word = 8,
@@ -117,7 +123,9 @@ static int lis3l02dq_spi_write_reg_s16(struct device *dev,
        int ret;
        struct spi_message msg;
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
-       struct lis3l02dq_state *st = iio_dev_get_devdata(indio_dev);
+       struct iio_sw_ring_helper_state *h
+               = iio_dev_get_devdata(indio_dev);
+       struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
        struct spi_transfer xfers[] = { {
                        .tx_buf = st->tx,
                        .bits_per_word = 8,
@@ -159,7 +167,9 @@ static int lis3l02dq_spi_read_reg_s16(struct device *dev,
 {
        struct spi_message msg;
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
-       struct lis3l02dq_state *st = iio_dev_get_devdata(indio_dev);
+       struct iio_sw_ring_helper_state *h
+               = iio_dev_get_devdata(indio_dev);
+       struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
        int ret;
        struct spi_transfer xfers[] = { {
                        .tx_buf = st->tx,
@@ -412,7 +422,7 @@ static int lis3l02dq_initial_setup(struct lis3l02dq_state *st)
 
        val = LIS3L02DQ_DEFAULT_CTRL1;
        /* Write suitable defaults to ctrl1 */
-       ret = lis3l02dq_spi_write_reg_8(&st->indio_dev->dev,
+       ret = lis3l02dq_spi_write_reg_8(&st->help.indio_dev->dev,
                                        LIS3L02DQ_REG_CTRL_1_ADDR,
                                        &val);
        if (ret) {
@@ -420,7 +430,7 @@ static int lis3l02dq_initial_setup(struct lis3l02dq_state *st)
                goto err_ret;
        }
        /* Repeat as sometimes doesn't work first time?*/
-       ret = lis3l02dq_spi_write_reg_8(&st->indio_dev->dev,
+       ret = lis3l02dq_spi_write_reg_8(&st->help.indio_dev->dev,
                                        LIS3L02DQ_REG_CTRL_1_ADDR,
                                        &val);
        if (ret) {
@@ -430,17 +440,17 @@ static int lis3l02dq_initial_setup(struct lis3l02dq_state *st)
 
        /* Read back to check this has worked acts as loose test of correct
         * chip */
-       ret = lis3l02dq_spi_read_reg_8(&st->indio_dev->dev,
+       ret = lis3l02dq_spi_read_reg_8(&st->help.indio_dev->dev,
                                       LIS3L02DQ_REG_CTRL_1_ADDR,
                                       &valtest);
        if (ret || (valtest != val)) {
-               dev_err(&st->indio_dev->dev, "device not playing ball");
+               dev_err(&st->help.indio_dev->dev, "device not playing ball");
                ret = -EINVAL;
                goto err_ret;
        }
 
        val = LIS3L02DQ_DEFAULT_CTRL2;
-       ret = lis3l02dq_spi_write_reg_8(&st->indio_dev->dev,
+       ret = lis3l02dq_spi_write_reg_8(&st->help.indio_dev->dev,
                                        LIS3L02DQ_REG_CTRL_2_ADDR,
                                        &val);
        if (ret) {
@@ -449,7 +459,7 @@ static int lis3l02dq_initial_setup(struct lis3l02dq_state *st)
        }
 
        val = LIS3L02DQ_REG_WAKE_UP_CFG_LATCH_SRC;
-       ret = lis3l02dq_spi_write_reg_8(&st->indio_dev->dev,
+       ret = lis3l02dq_spi_write_reg_8(&st->help.indio_dev->dev,
                                        LIS3L02DQ_REG_WAKE_UP_CFG_ADDR,
                                        &val);
        if (ret)
@@ -595,15 +605,17 @@ error_mutex_unlock:
 }
 
 
-static int lis3l02dq_thresh_handler_th(struct iio_dev *dev_info,
+static int lis3l02dq_thresh_handler_th(struct iio_dev *indio_dev,
                                       int index,
                                       s64 timestamp,
                                       int no_test)
 {
-       struct lis3l02dq_state *st = dev_info->dev_data;
+       struct iio_sw_ring_helper_state *h
+               = iio_dev_get_devdata(indio_dev);
+       struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
 
        /* Stash the timestamp somewhere convenient for the bh */
-       st->last_timestamp = timestamp;
+       h->last_timestamp = timestamp;
        schedule_work(&st->work_thresh);
 
        return 0;
@@ -621,43 +633,43 @@ static void lis3l02dq_thresh_handler_bh_no_check(struct work_struct *work_s)
 
        u8 t;
 
-       lis3l02dq_spi_read_reg_8(&st->indio_dev->dev,
+       lis3l02dq_spi_read_reg_8(&st->help.indio_dev->dev,
                                 LIS3L02DQ_REG_WAKE_UP_SRC_ADDR,
                                 &t);
 
        if (t & LIS3L02DQ_REG_WAKE_UP_SRC_INTERRUPT_Z_HIGH)
-               iio_push_event(st->indio_dev, 0,
+               iio_push_event(st->help.indio_dev, 0,
                               IIO_EVENT_CODE_ACCEL_Z_HIGH,
-                              st->last_timestamp);
+                              st->help.last_timestamp);
 
        if (t & LIS3L02DQ_REG_WAKE_UP_SRC_INTERRUPT_Z_LOW)
-               iio_push_event(st->indio_dev, 0,
+               iio_push_event(st->help.indio_dev, 0,
                               IIO_EVENT_CODE_ACCEL_Z_LOW,
-                              st->last_timestamp);
+                              st->help.last_timestamp);
 
        if (t & LIS3L02DQ_REG_WAKE_UP_SRC_INTERRUPT_Y_HIGH)
-               iio_push_event(st->indio_dev, 0,
+               iio_push_event(st->help.indio_dev, 0,
                               IIO_EVENT_CODE_ACCEL_Y_HIGH,
-                              st->last_timestamp);
+                              st->help.last_timestamp);
 
        if (t & LIS3L02DQ_REG_WAKE_UP_SRC_INTERRUPT_Y_LOW)
-               iio_push_event(st->indio_dev, 0,
+               iio_push_event(st->help.indio_dev, 0,
                               IIO_EVENT_CODE_ACCEL_Y_LOW,
-                              st->last_timestamp);
+                              st->help.last_timestamp);
 
        if (t & LIS3L02DQ_REG_WAKE_UP_SRC_INTERRUPT_X_HIGH)
-               iio_push_event(st->indio_dev, 0,
+               iio_push_event(st->help.indio_dev, 0,
                               IIO_EVENT_CODE_ACCEL_X_HIGH,
-                              st->last_timestamp);
+                              st->help.last_timestamp);
 
        if (t & LIS3L02DQ_REG_WAKE_UP_SRC_INTERRUPT_X_LOW)
-               iio_push_event(st->indio_dev, 0,
+               iio_push_event(st->help.indio_dev, 0,
                               IIO_EVENT_CODE_ACCEL_X_LOW,
-                              st->last_timestamp);
+                              st->help.last_timestamp);
        /* reenable the irq */
        enable_irq(st->us->irq);
        /* Ack and allow for new interrupts */
-       lis3l02dq_spi_read_reg_8(&st->indio_dev->dev,
+       lis3l02dq_spi_read_reg_8(&st->help.indio_dev->dev,
                                 LIS3L02DQ_REG_WAKE_UP_ACK_ADDR,
                                 &t);
 
@@ -769,30 +781,30 @@ static int __devinit lis3l02dq_probe(struct spi_device *spi)
        st->us = spi;
        mutex_init(&st->buf_lock);
        /* setup the industrialio driver allocated elements */
-       st->indio_dev = iio_allocate_device();
-       if (st->indio_dev == NULL) {
+       st->help.indio_dev = iio_allocate_device();
+       if (st->help.indio_dev == NULL) {
                ret = -ENOMEM;
                goto error_free_tx;
        }
 
-       st->indio_dev->dev.parent = &spi->dev;
-       st->indio_dev->num_interrupt_lines = 1;
-       st->indio_dev->event_attrs = &lis3l02dq_event_attribute_group;
-       st->indio_dev->attrs = &lis3l02dq_attribute_group;
-       st->indio_dev->dev_data = (void *)(st);
-       st->indio_dev->driver_module = THIS_MODULE;
-       st->indio_dev->modes = INDIO_DIRECT_MODE;
+       st->help.indio_dev->dev.parent = &spi->dev;
+       st->help.indio_dev->num_interrupt_lines = 1;
+       st->help.indio_dev->event_attrs = &lis3l02dq_event_attribute_group;
+       st->help.indio_dev->attrs = &lis3l02dq_attribute_group;
+       st->help.indio_dev->dev_data = (void *)(&st->help);
+       st->help.indio_dev->driver_module = THIS_MODULE;
+       st->help.indio_dev->modes = INDIO_DIRECT_MODE;
 
-       ret = lis3l02dq_configure_ring(st->indio_dev);
+       ret = lis3l02dq_configure_ring(st->help.indio_dev);
        if (ret)
                goto error_free_dev;
 
-       ret = iio_device_register(st->indio_dev);
+       ret = iio_device_register(st->help.indio_dev);
        if (ret)
                goto error_unreg_ring_funcs;
        regdone = 1;
 
-       ret = iio_ring_buffer_register(st->indio_dev->ring, 0);
+       ret = iio_ring_buffer_register(st->help.indio_dev->ring, 0);
        if (ret) {
                printk(KERN_ERR "failed to initialize the ring\n");
                goto error_unreg_ring_funcs;
@@ -801,14 +813,14 @@ static int __devinit lis3l02dq_probe(struct spi_device *spi)
        if (spi->irq && gpio_is_valid(irq_to_gpio(spi->irq)) > 0) {
                st->inter = 0;
                ret = iio_register_interrupt_line(spi->irq,
-                                                 st->indio_dev,
+                                                 st->help.indio_dev,
                                                  0,
                                                  IRQF_TRIGGER_RISING,
                                                  "lis3l02dq");
                if (ret)
                        goto error_uninitialize_ring;
 
-               ret = lis3l02dq_probe_trigger(st->indio_dev);
+               ret = lis3l02dq_probe_trigger(st->help.indio_dev);
                if (ret)
                        goto error_unregister_line;
        }
@@ -820,20 +832,20 @@ static int __devinit lis3l02dq_probe(struct spi_device *spi)
        return 0;
 
 error_remove_trigger:
-       if (st->indio_dev->modes & INDIO_RING_TRIGGERED)
-               lis3l02dq_remove_trigger(st->indio_dev);
+       if (st->help.indio_dev->modes & INDIO_RING_TRIGGERED)
+               lis3l02dq_remove_trigger(st->help.indio_dev);
 error_unregister_line:
-       if (st->indio_dev->modes & INDIO_RING_TRIGGERED)
-               iio_unregister_interrupt_line(st->indio_dev, 0);
+       if (st->help.indio_dev->modes & INDIO_RING_TRIGGERED)
+               iio_unregister_interrupt_line(st->help.indio_dev, 0);
 error_uninitialize_ring:
-       iio_ring_buffer_unregister(st->indio_dev->ring);
+       iio_ring_buffer_unregister(st->help.indio_dev->ring);
 error_unreg_ring_funcs:
-       lis3l02dq_unconfigure_ring(st->indio_dev);
+       lis3l02dq_unconfigure_ring(st->help.indio_dev);
 error_free_dev:
        if (regdone)
-               iio_device_unregister(st->indio_dev);
+               iio_device_unregister(st->help.indio_dev);
        else
-               iio_free_device(st->indio_dev);
+               iio_free_device(st->help.indio_dev);
 error_free_tx:
        kfree(st->tx);
 error_free_rx:
@@ -848,7 +860,9 @@ error_ret:
 static int lis3l02dq_stop_device(struct iio_dev *indio_dev)
 {
        int ret;
-       struct lis3l02dq_state *st = indio_dev->dev_data;
+       struct iio_sw_ring_helper_state *h
+               = iio_dev_get_devdata(indio_dev);
+       struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
        u8 val = 0;
 
        mutex_lock(&indio_dev->mlock);
@@ -875,7 +889,7 @@ static int lis3l02dq_remove(struct spi_device *spi)
 {
        int ret;
        struct lis3l02dq_state *st = spi_get_drvdata(spi);
-       struct iio_dev *indio_dev = st->indio_dev;
+       struct iio_dev *indio_dev = st->help.indio_dev;
 
        ret = lis3l02dq_stop_device(indio_dev);
        if (ret)
index 2c11209..a960a8f 100644 (file)
@@ -105,11 +105,13 @@ static struct attribute_group lis3l02dq_scan_el_group = {
  **/
 static void lis3l02dq_poll_func_th(struct iio_dev *indio_dev, s64 time)
 {
-       struct lis3l02dq_state *st = iio_dev_get_devdata(indio_dev);
-       st->last_timestamp = time;
-       schedule_work(&st->work_trigger_to_ring);
-       /* Indicate that this interrupt is being handled */
+       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.
@@ -120,15 +122,16 @@ static void lis3l02dq_poll_func_th(struct iio_dev *indio_dev, s64 time)
 /**
  * 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,
+static int lis3l02dq_data_rdy_trig_poll(struct iio_dev *indio_dev,
                                       int index,
                                       s64 timestamp,
                                       int no_test)
 {
-       struct lis3l02dq_state *st = iio_dev_get_devdata(dev_info);
-       struct iio_trigger *trig = st->trig;
+       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(trig, timestamp);
+       iio_trigger_poll(st->trig, timestamp);
 
        return IRQ_HANDLED;
 }
@@ -212,7 +215,7 @@ static int lis3l02dq_read_all(struct lis3l02dq_state *st, u8 *rx_array)
        struct spi_message msg;
        int ret, i, j = 0;
 
-       xfers = kzalloc((st->indio_dev->scan_count) * 2
+       xfers = kzalloc((st->help.indio_dev->scan_count) * 2
                        * sizeof(*xfers), GFP_KERNEL);
        if (!xfers)
                return -ENOMEM;
@@ -220,7 +223,7 @@ static int lis3l02dq_read_all(struct lis3l02dq_state *st, u8 *rx_array)
        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)) {
+               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];
@@ -248,7 +251,7 @@ static int lis3l02dq_read_all(struct lis3l02dq_state *st, u8 *rx_array)
         * values in alternate bytes
         */
        spi_message_init(&msg);
-       for (j = 0; j < st->indio_dev->scan_count * 2; j++)
+       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);
@@ -258,62 +261,36 @@ static int lis3l02dq_read_all(struct lis3l02dq_state *st, u8 *rx_array)
        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");
-               kfree(data);
-               return;
-       }
+       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);
 
-       /* 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;
+       iio_sw_trigger_bh_to_ring(work_s);
+}
 
-       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);
+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;
 
-       iio_trigger_notify_done(st->indio_dev->trig);
+       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);
-       kfree(data);
 
-       return;
+       return i*sizeof(data[0]);
 }
 
 /* Caller responsible for locking as necessary. */
@@ -387,7 +364,7 @@ static int lis3l02dq_data_rdy_trigger_set_state(struct iio_trigger *trig,
        struct lis3l02dq_state *st = trig->private_data;
        int ret = 0;
        u8 t;
-       __lis3l02dq_write_data_ready_config(&st->indio_dev->dev,
+       __lis3l02dq_write_data_ready_config(&st->help.indio_dev->dev,
                                            &iio_event_data_rdy_trig,
                                            state);
        if (state == false) {
@@ -397,7 +374,7 @@ static int lis3l02dq_data_rdy_trigger_set_state(struct iio_trigger *trig,
                /* Clear any outstanding ready events */
                ret = lis3l02dq_read_all(st, NULL);
        }
-       lis3l02dq_spi_read_reg_8(&st->indio_dev->dev,
+       lis3l02dq_spi_read_reg_8(&st->help.indio_dev->dev,
                                 LIS3L02DQ_REG_WAKE_UP_SRC_ADDR,
                                 &t);
        return ret;
@@ -500,12 +477,12 @@ void lis3l02dq_unconfigure_ring(struct iio_dev *indio_dev)
 
 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 */
+       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);
@@ -513,19 +490,17 @@ int lis3l02dq_configure_ring(struct iio_dev *indio_dev)
 
        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;
+       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(&ring->access);
-       ring->bpe = 2;
-       ring->preenable = &iio_sw_ring_preenable;
-       ring->postenable = &iio_triggered_ring_postenable;
-       ring->predisable = &iio_triggered_ring_predisable;
-       ring->owner = THIS_MODULE;
+       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)
@@ -537,6 +512,3 @@ error_iio_sw_rb_free:
        iio_sw_rb_free(indio_dev->ring);
        return ret;
 }
-
-
-