1 files changed, 124 insertions, 107 deletions

diff --git a/drivers/staging/iio/meter/ade7758_ring.c b/drivers/staging/iio/meter/ade7758_ring.c
index 2c9865d..c8ebfd2 100644
--- a/drivers/staging/iio/meter/ade7758_ring.c
+++ b/drivers/staging/iio/meter/ade7758_ring.c
@@ -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"
@@ -18,82 +26,40 @@
 #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);