staging:iio:meter:ade7758: Use iio channel spec and miscellaneous other changes.
authorMichael Hennerich <michael.hennerich@analog.com>
Wed, 18 May 2011 13:42:07 +0000 (14:42 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 19 May 2011 23:14:59 +0000 (16:14 -0700)
Use iio channel spec for the ring buffer channels.
Add/update file comment/license headers.
Use available_scan_masks to prevent that multiple channels are enabled.
Remove wavefrom type attributes. (no handled directly by the scan_elements)
Use SPI_MODE_1.
Move ade7758_initial_setup() before ade7758_probe_trigger() to ensure the
ADE7758 interrupt is disabled when the host interrupt get's enabled.
Add spi_device_id.
Update ring buffer setup.

Some backporting needed to ensure driver builds all the way through core
changes.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/staging/iio/meter/ade7758.h
drivers/staging/iio/meter/ade7758_core.c
drivers/staging/iio/meter/ade7758_ring.c

index 169982b..372a9f6 100644 (file)
@@ -1,3 +1,11 @@
+/*
+ * ADE7758 Poly Phase Multifunction Energy Metering IC driver
+ *
+ * Copyright 2010-2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
 #ifndef _ADE7758_H
 #define _ADE7758_H
 
 #define ADE7758_MAX_RX    4
 #define ADE7758_STARTUP_DELAY 1
 
-#define ADE7758_SPI_SLOW       (u32)(300 * 1000)
-#define ADE7758_SPI_BURST      (u32)(1000 * 1000)
-#define ADE7758_SPI_FAST       (u32)(2000 * 1000)
+#define AD7758_NUM_WAVSEL      5
+#define AD7758_NUM_PHSEL       3
+#define AD7758_NUM_WAVESRC     (AD7758_NUM_WAVSEL * AD7758_NUM_PHSEL)
+
+#define AD7758_PHASE_A         0
+#define AD7758_PHASE_B         1
+#define AD7758_PHASE_C         2
+#define AD7758_CURRENT         0
+#define AD7758_VOLTAGE         1
+#define AD7758_ACT_PWR         2
+#define AD7758_REACT_PWR       3
+#define AD7758_APP_PWR         4
+#define AD7758_WT(p, w)                (((w) << 2) | (p))
 
 #define DRIVER_NAME            "ade7758"
 
+
 /**
  * struct ade7758_state - device instance specific data
  * @us:                        actual spi_device
  * @buf_lock:          mutex to protect tx and rx
  **/
 struct ade7758_state {
-       struct spi_device               *us;
-       struct iio_dev                  *indio_dev;
-       struct iio_trigger              *trig;
-       u8                              *tx;
-       u8                              *rx;
-       struct mutex                    buf_lock;
+       struct spi_device       *us;
+       struct iio_dev          *indio_dev;
+       struct iio_trigger      *trig;
+       u8                      *tx;
+       u8                      *rx;
+       struct mutex            buf_lock;
+       u32                     available_scan_masks[AD7758_NUM_WAVESRC];
+       struct iio_chan_spec    *ade7758_ring_channels;
+       struct spi_transfer             ring_xfer[4];
+       struct spi_message              ring_msg;
+       /*
+        * DMA (thus cache coherency maintenance) requires the
+        * transfer buffers to live in their own cache lines.
+        */
+       unsigned char                   rx_buf[8] ____cacheline_aligned;
+       unsigned char                   tx_buf[8];
+
 };
 #ifdef CONFIG_IIO_RING_BUFFER
 /* At the moment triggers are only used for ring buffer
  * filling. This may change!
  */
 
-enum ade7758_scan {
-       ADE7758_SCAN_WFORM,
-};
-
 void ade7758_remove_trigger(struct iio_dev *indio_dev);
 int ade7758_probe_trigger(struct iio_dev *indio_dev);
 
@@ -129,6 +155,12 @@ void ade7758_unconfigure_ring(struct iio_dev *indio_dev);
 int ade7758_initialize_ring(struct iio_ring_buffer *ring);
 void ade7758_uninitialize_ring(struct iio_ring_buffer *ring);
 int ade7758_set_irq(struct device *dev, bool enable);
+
+int ade7758_spi_write_reg_8(struct device *dev,
+               u8 reg_address, u8 val);
+int ade7758_spi_read_reg_8(struct device *dev,
+               u8 reg_address, u8 *val);
+
 #else /* CONFIG_IIO_RING_BUFFER */
 
 static inline void ade7758_remove_trigger(struct iio_dev *indio_dev)
@@ -139,14 +171,6 @@ static inline int ade7758_probe_trigger(struct iio_dev *indio_dev)
        return 0;
 }
 
-static inline ssize_t
-ade7758_read_data_from_ring(struct device *dev,
-               struct device_attribute *attr,
-               char *buf)
-{
-       return 0;
-}
-
 static int ade7758_configure_ring(struct iio_dev *indio_dev)
 {
        return 0;
index 26ff31b..42682ad 100644 (file)
 
 #include "../iio.h"
 #include "../sysfs.h"
+#include "../ring_generic.h"
 #include "meter.h"
 #include "ade7758.h"
 
-static int ade7758_spi_write_reg_8(struct device *dev,
+int ade7758_spi_write_reg_8(struct device *dev,
                u8 reg_address,
                u8 val)
 {
@@ -490,7 +491,7 @@ static int ade7758_initial_setup(struct ade7758_state *st)
        struct device *dev = &st->indio_dev->dev;
 
        /* use low spi speed for init */
-       st->us->mode = SPI_MODE_3;
+       st->us->mode = SPI_MODE_1;
        spi_setup(st->us);
 
        /* Disable IRQ */
@@ -580,63 +581,6 @@ out:
        return ret ? ret : len;
 }
 
-static ssize_t ade7758_read_waveform_type(struct device *dev,
-               struct device_attribute *attr,
-               char *buf)
-{
-       int ret, len = 0;
-       u8 t;
-       ret = ade7758_spi_read_reg_8(dev,
-                       ADE7758_WAVMODE,
-                       &t);
-       if (ret)
-               return ret;
-
-       t = (t >> 2) & 0x7;
-
-       len = sprintf(buf, "%d\n", t);
-
-       return len;
-}
-
-static ssize_t ade7758_write_waveform_type(struct device *dev,
-               struct device_attribute *attr,
-               const char *buf,
-               size_t len)
-{
-       struct iio_dev *indio_dev = dev_get_drvdata(dev);
-       unsigned long val;
-       int ret;
-       u8 reg;
-
-       ret = strict_strtol(buf, 10, &val);
-       if (ret)
-               return ret;
-
-       if (val > 4)
-               return -EINVAL;
-
-       mutex_lock(&indio_dev->mlock);
-
-       ret = ade7758_spi_read_reg_8(dev,
-                       ADE7758_WAVMODE,
-                       &reg);
-       if (ret)
-               goto out;
-
-       reg &= ~(7 << 2);
-       reg |= val << 2;
-
-       ret = ade7758_spi_write_reg_8(dev,
-                       ADE7758_WAVMODE,
-                       reg);
-
-out:
-       mutex_unlock(&indio_dev->mlock);
-
-       return ret ? ret : len;
-}
-
 static IIO_DEV_ATTR_TEMP_RAW(ade7758_read_8bit);
 static IIO_CONST_ATTR(temp_offset, "129 C");
 static IIO_CONST_ATTR(temp_scale, "4 C");
@@ -664,19 +608,6 @@ static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
                ade7758_read_frequency,
                ade7758_write_frequency);
 
-/**
- * IIO_DEV_ATTR_WAVEFORM_TYPE - set the type of waveform.
- * @_mode: sysfs file mode/permissions
- * @_show: output method for the attribute
- * @_store: input method for the attribute
- **/
-#define IIO_DEV_ATTR_WAVEFORM_TYPE(_mode, _show, _store)                       \
-       IIO_DEVICE_ATTR(waveform_type, _mode, _show, _store, 0)
-
-static IIO_DEV_ATTR_WAVEFORM_TYPE(S_IWUSR | S_IRUGO,
-               ade7758_read_waveform_type,
-               ade7758_write_waveform_type);
-
 static IIO_DEV_ATTR_RESET(ade7758_write_reset);
 
 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("26040 13020 6510 3255");
@@ -686,7 +617,6 @@ static struct attribute *ade7758_attributes[] = {
        &iio_const_attr_temp_offset.dev_attr.attr,
        &iio_const_attr_temp_scale.dev_attr.attr,
        &iio_dev_attr_sampling_frequency.dev_attr.attr,
-       &iio_dev_attr_waveform_type.dev_attr.attr,
        &iio_const_attr_sampling_frequency_available.dev_attr.attr,
        &iio_dev_attr_reset.dev_attr.attr,
        &iio_dev_attr_awatthr.dev_attr.attr,
@@ -730,11 +660,73 @@ static const struct attribute_group ade7758_attribute_group = {
        .attrs = ade7758_attributes,
 };
 
-
+static struct iio_chan_spec ade7758_channels[] = {
+       IIO_CHAN(IIO_IN, 0, 1, 0, "raw", 0, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_A, AD7758_VOLTAGE),
+               0, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_CURRENT, 0, 1, 0, "raw", 0, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_A, AD7758_CURRENT),
+               1, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_POWER, 0, 1, 0, "apparent_raw", 0, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_A, AD7758_APP_PWR),
+               2, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_POWER, 0, 1, 0, "active_raw", 0, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_A, AD7758_ACT_PWR),
+               3, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_POWER, 0, 1, 0, "reactive_raw", 0, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_A, AD7758_REACT_PWR),
+               4, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_IN, 0, 1, 0, "raw", 1, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_B, AD7758_VOLTAGE),
+               5, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_CURRENT, 0, 1, 0, "raw", 1, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_B, AD7758_CURRENT),
+               6, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_POWER, 0, 1, 0, "apparent_raw", 1, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_B, AD7758_APP_PWR),
+               7, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_POWER, 0, 1, 0, "active_raw", 1, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_B, AD7758_ACT_PWR),
+               8, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_POWER, 0, 1, 0, "reactive_raw", 1, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_B, AD7758_REACT_PWR),
+               9, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_IN, 0, 1, 0, "raw", 2, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_C, AD7758_VOLTAGE),
+               10, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_CURRENT, 0, 1, 0, "raw", 2, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_C, AD7758_CURRENT),
+               11, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_POWER, 0, 1, 0, "apparent_raw", 2, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_C, AD7758_APP_PWR),
+               12, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_POWER, 0, 1, 0, "active_raw", 2, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_C, AD7758_ACT_PWR),
+               13, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN(IIO_POWER, 0, 1, 0, "reactive_raw", 2, 0,
+               (1 << IIO_CHAN_INFO_SCALE_SHARED),
+               AD7758_WT(AD7758_PHASE_C, AD7758_REACT_PWR),
+               14, IIO_ST('s', 24, 32, 0), 0),
+       IIO_CHAN_SOFT_TIMESTAMP(15),
+};
 
 static int __devinit ade7758_probe(struct spi_device *spi)
 {
-       int ret, regdone = 0;
+       int i, ret, regdone = 0;
        struct ade7758_state *st = kzalloc(sizeof *st, GFP_KERNEL);
        if (!st) {
                ret =  -ENOMEM;
@@ -755,6 +747,7 @@ static int __devinit ade7758_probe(struct spi_device *spi)
                goto error_free_rx;
        }
        st->us = spi;
+       st->ade7758_ring_channels = &ade7758_channels[0];
        mutex_init(&st->buf_lock);
        /* setup the industrialio driver allocated elements */
        st->indio_dev = iio_allocate_device(0);
@@ -770,6 +763,11 @@ static int __devinit ade7758_probe(struct spi_device *spi)
        st->indio_dev->driver_module = THIS_MODULE;
        st->indio_dev->modes = INDIO_DIRECT_MODE;
 
+       for (i = 0; i < AD7758_NUM_WAVESRC; i++)
+               st->available_scan_masks[i] = 1 << i;
+
+       st->indio_dev->available_scan_masks = st->available_scan_masks;
+
        ret = ade7758_configure_ring(st->indio_dev);
        if (ret)
                goto error_free_dev;
@@ -779,22 +777,25 @@ static int __devinit ade7758_probe(struct spi_device *spi)
                goto error_unreg_ring_funcs;
        regdone = 1;
 
-       ret = ade7758_initialize_ring(st->indio_dev->ring);
+       ret = iio_ring_buffer_register_ex(st->indio_dev->ring, 0,
+                                         &ade7758_channels[0],
+                                         ARRAY_SIZE(ade7758_channels));
        if (ret) {
-               printk(KERN_ERR "failed to initialize the ring\n");
+               dev_err(&spi->dev, "failed to initialize the ring\n");
                goto error_unreg_ring_funcs;
        }
 
+       /* Get the device into a sane initial state */
+       ret = ade7758_initial_setup(st);
+       if (ret)
+               goto error_uninitialize_ring;
+
        if (spi->irq) {
                ret = ade7758_probe_trigger(st->indio_dev);
                if (ret)
-                       goto error_uninitialize_ring;
+                       goto error_remove_trigger;
        }
 
-       /* Get the device into a sane initial state */
-       ret = ade7758_initial_setup(st);
-       if (ret)
-               goto error_remove_trigger;
        return 0;
 
 error_remove_trigger:
@@ -829,8 +830,6 @@ static int ade7758_remove(struct spi_device *spi)
        if (ret)
                goto err_ret;
 
-       flush_scheduled_work();
-
        ade7758_remove_trigger(indio_dev);
        ade7758_uninitialize_ring(indio_dev->ring);
        iio_device_unregister(indio_dev);
@@ -845,6 +844,11 @@ err_ret:
        return ret;
 }
 
+static const struct spi_device_id ade7758_id[] = {
+       {"ade7758", 0},
+       {}
+};
+
 static struct spi_driver ade7758_driver = {
        .driver = {
                .name = "ade7758",
@@ -852,6 +856,7 @@ static struct spi_driver ade7758_driver = {
        },
        .probe = ade7758_probe,
        .remove = __devexit_p(ade7758_remove),
+       .id_table = ade7758_id,
 };
 
 static __init int ade7758_init(void)
index 2c9865d..c8ebfd2 100644 (file)
@@ -1,3 +1,10 @@
+/*
+ * ADE7758 Poly Phase Multifunction Energy Metering IC driver
+ *
+ * Copyright 2010-2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/gpio.h>
@@ -9,6 +16,7 @@
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/list.h>
+#include <asm/unaligned.h>
 
 #include "../iio.h"
 #include "../sysfs.h"
 #include "ade7758.h"
 
 /**
- * combine_8_to_32() utility function to munge to u8s into u32
- **/
-static inline u32 combine_8_to_32(u8 lower, u8 mid, u8 upper)
-{
-       u32 _lower = lower;
-       u32 _mid = mid;
-       u32 _upper = upper;
-
-       return _lower | (_mid << 8) | (_upper << 16);
-}
-
-static IIO_SCAN_EL_C(wform, ADE7758_SCAN_WFORM, ADE7758_WFORM, NULL);
-static IIO_CONST_ATTR_SCAN_EL_TYPE(wform, s, 24, 32);
-static IIO_SCAN_EL_TIMESTAMP(1);
-static IIO_CONST_ATTR_SCAN_EL_TYPE(timestamp, s, 64, 64);
-
-static struct attribute *ade7758_scan_el_attrs[] = {
-       &iio_scan_el_wform.dev_attr.attr,
-       &iio_const_attr_wform_index.dev_attr.attr,
-       &iio_const_attr_wform_type.dev_attr.attr,
-       &iio_scan_el_timestamp.dev_attr.attr,
-       &iio_const_attr_timestamp_index.dev_attr.attr,
-       &iio_const_attr_timestamp_type.dev_attr.attr,
-       NULL,
-};
-
-static struct attribute_group ade7758_scan_el_group = {
-       .attrs = ade7758_scan_el_attrs,
-       .name = "scan_elements",
-};
-
-/**
- * ade7758_spi_read_burst() - read all data registers
+ * ade7758_spi_read_burst() - read data registers
  * @dev: device associated with child of actual device (iio_dev or iio_trig)
- * @rx: somewhere to pass back the value read (min size is 24 bytes)
  **/
-static int ade7758_spi_read_burst(struct device *dev, u8 *rx)
+static int ade7758_spi_read_burst(struct device *dev)
 {
-       struct spi_message msg;
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct ade7758_state *st = iio_dev_get_devdata(indio_dev);
        int ret;
 
-       struct spi_transfer xfers[] = {
-               {
-                       .tx_buf = st->tx,
-                       .rx_buf = rx,
-                       .bits_per_word = 8,
-                       .len = 4,
-               }, {
-                       .tx_buf = st->tx + 4,
-                       .rx_buf = rx,
-                       .bits_per_word = 8,
-                       .len = 4,
-               },
-       };
-
-       mutex_lock(&st->buf_lock);
-       st->tx[0] = ADE7758_READ_REG(ADE7758_RSTATUS);
-       st->tx[1] = 0;
-       st->tx[2] = 0;
-       st->tx[3] = 0;
-       st->tx[4] = ADE7758_READ_REG(ADE7758_WFORM);
-       st->tx[5] = 0;
-       st->tx[6] = 0;
-       st->tx[7] = 0;
-
-       spi_message_init(&msg);
-       spi_message_add_tail(&xfers[0], &msg);
-       spi_message_add_tail(&xfers[1], &msg);
-       ret = spi_sync(st->us, &msg);
+       ret = spi_sync(st->us, &st->ring_msg);
        if (ret)
                dev_err(&st->us->dev, "problem when reading WFORM value\n");
 
-       mutex_unlock(&st->buf_lock);
+       return ret;
+}
+
+static int ade7758_write_waveform_type(struct device *dev, unsigned type)
+{
+       int ret;
+       u8 reg;
+
+       ret = ade7758_spi_read_reg_8(dev,
+                       ADE7758_WAVMODE,
+                       &reg);
+       if (ret)
+               goto out;
+
+       reg &= ~0x1F;
+       reg |= type & 0x1F;
 
+       ret = ade7758_spi_write_reg_8(dev,
+                       ADE7758_WAVMODE,
+                       reg);
+out:
        return ret;
 }
 
@@ -106,41 +72,70 @@ static irqreturn_t ade7758_trigger_handler(int irq, void *p)
        struct iio_dev *indio_dev = pf->private_data;
        struct iio_ring_buffer *ring = indio_dev->ring;
        struct ade7758_state *st = iio_dev_get_devdata(indio_dev);
-       int i = 0;
-       s32 *data;
-       size_t datasize = ring->access.get_bytes_per_datum(ring);
-
-       data = kmalloc(datasize, GFP_KERNEL);
-       if (data == NULL) {
-               dev_err(&st->us->dev, "memory alloc failed in ring bh");
-               return -ENOMEM;
-       }
+       s64 dat64[2];
+       u32 *dat32 = (u32 *)dat64;
 
        if (ring->scan_count)
-               if (ade7758_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
-                       for (; i < ring->scan_count; i++)
-                               data[i] = combine_8_to_32(st->rx[i*2+2],
-                                               st->rx[i*2+1],
-                                               st->rx[i*2]);
+               if (ade7758_spi_read_burst(&st->indio_dev->dev) >= 0)
+                       *dat32 = get_unaligned_be32(&st->rx_buf[5]) & 0xFFFFFF;
 
        /* Guaranteed to be aligned with 8 byte boundary */
        if (ring->scan_timestamp)
-               *((s64 *)
-               (((u32)data + 4 * ring->scan_count + 4) & ~0x7)) =
-                       pf->timestamp;
+               dat64[1] = pf->timestamp;
 
-       ring->access.store_to(ring,
-                             (u8 *)data,
-                             pf->timestamp);
+       ring->access.store_to(ring, (u8 *)dat64, pf->timestamp);
 
        iio_trigger_notify_done(st->indio_dev->trig);
-       kfree(data);
 
        return IRQ_HANDLED;
 }
 
+/**
+ * ade7758_ring_preenable() setup the parameters of the ring before enabling
+ *
+ * The complex nature of the setting of the nuber of bytes per datum is due
+ * to this driver currently ensuring that the timestamp is stored at an 8
+ * byte boundary.
+ **/
+static int ade7758_ring_preenable(struct iio_dev *indio_dev)
+{
+       struct ade7758_state *st = indio_dev->dev_data;
+       struct iio_ring_buffer *ring = indio_dev->ring;
+       size_t d_size;
+       unsigned channel;
+
+       if (!ring->scan_count)
+               return -EINVAL;
+
+       channel = __ffs(ring->scan_mask);
+
+       d_size = st->ade7758_ring_channels[channel].scan_type.storagebits / 8;
+
+       if (ring->scan_timestamp) {
+               d_size += sizeof(s64);
+
+               if (d_size % sizeof(s64))
+                       d_size += sizeof(s64) - (d_size % sizeof(s64));
+       }
+
+       if (indio_dev->ring->access.set_bytes_per_datum)
+               indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring,
+                                                           d_size);
+
+       ade7758_write_waveform_type(&indio_dev->dev,
+               st->ade7758_ring_channels[channel].address);
+
+       return 0;
+}
+
 void ade7758_unconfigure_ring(struct iio_dev *indio_dev)
 {
+       /* ensure that the trigger has been detached */
+       if (indio_dev->trig) {
+               iio_put_trigger(indio_dev->trig);
+               iio_trigger_dettach_poll_func(indio_dev->trig,
+                                             indio_dev->pollfunc);
+       }
        kfree(indio_dev->pollfunc->name);
        kfree(indio_dev->pollfunc);
        iio_sw_rb_free(indio_dev->ring);
@@ -148,34 +143,28 @@ void ade7758_unconfigure_ring(struct iio_dev *indio_dev)
 
 int ade7758_configure_ring(struct iio_dev *indio_dev)
 {
+       struct ade7758_state *st = indio_dev->dev_data;
        int ret = 0;
-       struct iio_ring_buffer *ring;
 
-       ring = iio_sw_rb_allocate(indio_dev);
-       if (!ring) {
+       indio_dev->ring = iio_sw_rb_allocate(indio_dev);
+       if (!indio_dev->ring) {
                ret = -ENOMEM;
                return ret;
        }
-       indio_dev->ring = ring;
+
        /* Effectively select the ring buffer implementation */
-       iio_ring_sw_register_funcs(&ring->access);
-       ring->bpe = 4;
-       ring->scan_el_attrs = &ade7758_scan_el_group;
-       ring->scan_timestamp = true;
-       ring->preenable = &iio_sw_ring_preenable;
-       ring->postenable = &iio_triggered_ring_postenable;
-       ring->predisable = &iio_triggered_ring_predisable;
-       ring->owner = THIS_MODULE;
-
-       /* Set default scan mode */
-       iio_scan_mask_set(ring, iio_scan_el_wform.number);
+       iio_ring_sw_register_funcs(&indio_dev->ring->access);
+       indio_dev->ring->preenable = &ade7758_ring_preenable;
+       indio_dev->ring->postenable = &iio_triggered_ring_postenable;
+       indio_dev->ring->predisable = &iio_triggered_ring_predisable;
+       indio_dev->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->private_data = indio_dev->ring;
+       indio_dev->pollfunc->private_data = indio_dev;
        indio_dev->pollfunc->h = &iio_pollfunc_store_time;
        indio_dev->pollfunc->thread = &ade7758_trigger_handler;
        indio_dev->pollfunc->name
@@ -186,6 +175,39 @@ int ade7758_configure_ring(struct iio_dev *indio_dev)
        }
        indio_dev->modes |= INDIO_RING_TRIGGERED;
 
+       st->tx_buf[0] = ADE7758_READ_REG(ADE7758_RSTATUS);
+       st->tx_buf[1] = 0;
+       st->tx_buf[2] = 0;
+       st->tx_buf[3] = 0;
+       st->tx_buf[4] = ADE7758_READ_REG(ADE7758_WFORM);
+       st->tx_buf[5] = 0;
+       st->tx_buf[6] = 0;
+       st->tx_buf[7] = 0;
+
+       /* build spi ring message */
+       st->ring_xfer[0].tx_buf = &st->tx_buf[0];
+       st->ring_xfer[0].len = 1;
+       st->ring_xfer[0].bits_per_word = 8;
+       st->ring_xfer[0].delay_usecs = 4;
+       st->ring_xfer[1].rx_buf = &st->rx_buf[1];
+       st->ring_xfer[1].len = 3;
+       st->ring_xfer[1].bits_per_word = 8;
+       st->ring_xfer[1].cs_change = 1;
+
+       st->ring_xfer[2].tx_buf = &st->tx_buf[4];
+       st->ring_xfer[2].len = 1;
+       st->ring_xfer[2].bits_per_word = 8;
+       st->ring_xfer[2].delay_usecs = 1;
+       st->ring_xfer[3].rx_buf = &st->rx_buf[5];
+       st->ring_xfer[3].len = 3;
+       st->ring_xfer[3].bits_per_word = 8;
+
+       spi_message_init(&st->ring_msg);
+       spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
+       spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
+       spi_message_add_tail(&st->ring_xfer[2], &st->ring_msg);
+       spi_message_add_tail(&st->ring_xfer[3], &st->ring_msg);
+
        return 0;
 
 error_free_pollfunc:
@@ -195,11 +217,6 @@ error_iio_sw_rb_free:
        return ret;
 }
 
-int ade7758_initialize_ring(struct iio_ring_buffer *ring)
-{
-       return iio_ring_buffer_register(ring, 0);
-}
-
 void ade7758_uninitialize_ring(struct iio_ring_buffer *ring)
 {
        iio_ring_buffer_unregister(ring);