1 files changed, 286 insertions, 0 deletions

diff --git a/drivers/staging/iio/imu/adis16350_ring.c b/drivers/staging/iio/imu/adis16350_ring.c
new file mode 100644
index 000000000000..5e9716ea7c77
--- /dev/null
+++ b/drivers/staging/iio/imu/adis16350_ring.c
@@ -0,0 +1,286 @@
+#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/accel.h"
+#include "../trigger.h"
+#include "adis16350.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);
+}
+
+static IIO_SCAN_EL_C(supply, ADIS16350_SCAN_SUPPLY, IIO_UNSIGNED(12),
+		ADIS16350_SUPPLY_OUT, NULL);
+
+static IIO_SCAN_EL_C(gyro_x, ADIS16350_SCAN_GYRO_X, IIO_SIGNED(14),
+		ADIS16350_XGYRO_OUT, NULL);
+static IIO_SCAN_EL_C(gyro_y, ADIS16350_SCAN_GYRO_Y, IIO_SIGNED(14),
+		ADIS16350_YGYRO_OUT, NULL);
+static IIO_SCAN_EL_C(gyro_z, ADIS16350_SCAN_GYRO_Z, IIO_SIGNED(14),
+		ADIS16350_ZGYRO_OUT, NULL);
+
+static IIO_SCAN_EL_C(accel_x, ADIS16350_SCAN_ACC_X, IIO_SIGNED(14),
+		ADIS16350_XACCL_OUT, NULL);
+static IIO_SCAN_EL_C(accel_y, ADIS16350_SCAN_ACC_Y, IIO_SIGNED(14),
+		ADIS16350_YACCL_OUT, NULL);
+static IIO_SCAN_EL_C(accel_z, ADIS16350_SCAN_ACC_Z, IIO_SIGNED(14),
+		ADIS16350_ZACCL_OUT, NULL);
+
+static IIO_SCAN_EL_C(temp_x, ADIS16350_SCAN_TEMP_X, IIO_SIGNED(12),
+		ADIS16350_XTEMP_OUT, NULL);
+static IIO_SCAN_EL_C(temp_y, ADIS16350_SCAN_TEMP_Y, IIO_SIGNED(12),
+		ADIS16350_YTEMP_OUT, NULL);
+static IIO_SCAN_EL_C(temp_z, ADIS16350_SCAN_TEMP_Z, IIO_SIGNED(12),
+		ADIS16350_ZTEMP_OUT, NULL);
+
+static IIO_SCAN_EL_C(adc_0, ADIS16350_SCAN_ADC_0, IIO_UNSIGNED(12),
+		ADIS16350_AUX_ADC, NULL);
+
+static IIO_SCAN_EL_TIMESTAMP(11);
+
+static struct attribute *adis16350_scan_el_attrs[] = {
+	&iio_scan_el_supply.dev_attr.attr,
+	&iio_scan_el_gyro_x.dev_attr.attr,
+	&iio_scan_el_gyro_y.dev_attr.attr,
+	&iio_scan_el_gyro_z.dev_attr.attr,
+	&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_temp_x.dev_attr.attr,
+	&iio_scan_el_temp_y.dev_attr.attr,
+	&iio_scan_el_temp_z.dev_attr.attr,
+	&iio_scan_el_adc_0.dev_attr.attr,
+	&iio_scan_el_timestamp.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute_group adis16350_scan_el_group = {
+	.attrs = adis16350_scan_el_attrs,
+	.name = "scan_elements",
+};
+
+/**
+ * adis16350_poll_func_th() top half interrupt handler called by trigger
+ * @private_data:	iio_dev
+ **/
+static void adis16350_poll_func_th(struct iio_dev *indio_dev)
+{
+	struct adis16350_state *st = iio_dev_get_devdata(indio_dev);
+	st->last_timestamp = indio_dev->trig->timestamp;
+	schedule_work(&st->work_trigger_to_ring);
+}
+
+/**
+ * adis16350_spi_read_burst() - read all 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 adis16350_spi_read_burst(struct device *dev, u8 *rx)
+{
+	struct spi_message msg;
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct adis16350_state *st = iio_dev_get_devdata(indio_dev);
+	u32 old_speed_hz = st->us->max_speed_hz;
+	int ret;
+
+	struct spi_transfer xfers[] = {
+		{
+			.tx_buf = st->tx,
+			.bits_per_word = 8,
+			.len = 2,
+			.cs_change = 0,
+		}, {
+			.rx_buf = rx,
+			.bits_per_word = 8,
+			.len = 22,
+			.cs_change = 0,
+		},
+	};
+
+	mutex_lock(&st->buf_lock);
+	st->tx[0] = ADIS16350_READ_REG(ADIS16350_GLOB_CMD);
+	st->tx[1] = 0;
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfers[0], &msg);
+	spi_message_add_tail(&xfers[1], &msg);
+
+	st->us->max_speed_hz = ADIS16350_SPI_BURST;
+	spi_setup(st->us);
+
+	ret = spi_sync(st->us, &msg);
+	if (ret)
+		dev_err(&st->us->dev, "problem when burst reading");
+
+	st->us->max_speed_hz = old_speed_hz;
+	spi_setup(st->us);
+	mutex_unlock(&st->buf_lock);
+	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 adis16350_trigger_bh_to_ring(struct work_struct *work_s)
+{
+	struct adis16350_state *st
+		= container_of(work_s, struct adis16350_state,
+			       work_trigger_to_ring);
+
+	int i = 0;
+	s16 *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;
+	}
+
+	if (st->indio_dev->scan_count)
+		if (adis16350_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
+			for (; i < st->indio_dev->scan_count; i++) {
+				data[i] = combine_8_to_16(st->rx[i*2+1],
+							  st->rx[i*2]);
+			}
+
+	/* 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(data);
+
+	return;
+}
+
+static int adis16350_data_rdy_ring_preenable(struct iio_dev *indio_dev)
+{
+	size_t size;
+	dev_dbg(&indio_dev->dev, "%s\n", __func__);
+	/* 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 (aligned sizeof(s64) and data */
+				size = (((indio_dev->scan_count * sizeof(s16))
+						+ sizeof(s64) - 1)
+					& ~(sizeof(s64) - 1))
+					+ 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 adis16350_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 adis16350_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;
+}
+
+void adis16350_unconfigure_ring(struct iio_dev *indio_dev)
+{
+	kfree(indio_dev->pollfunc);
+	iio_sw_rb_free(indio_dev->ring);
+}
+
+int adis16350_configure_ring(struct iio_dev *indio_dev)
+{
+	int ret = 0;
+	struct adis16350_state *st = indio_dev->dev_data;
+	struct iio_ring_buffer *ring;
+	INIT_WORK(&st->work_trigger_to_ring, adis16350_trigger_bh_to_ring);
+	/* Set default scan mode */
+
+	iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
+	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
+	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_y.number);
+	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_z.number);
+	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);
+	iio_scan_mask_set(indio_dev, iio_scan_el_temp_x.number);
+	iio_scan_mask_set(indio_dev, iio_scan_el_temp_y.number);
+	iio_scan_mask_set(indio_dev, iio_scan_el_temp_z.number);
+	iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
+	indio_dev->scan_timestamp = true;
+
+	indio_dev->scan_el_attrs = &adis16350_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 = &adis16350_data_rdy_ring_preenable;
+	ring->postenable = &adis16350_data_rdy_ring_postenable;
+	ring->predisable = &adis16350_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 = &adis16350_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 adis16350_initialize_ring(struct iio_ring_buffer *ring)
+{
+	return iio_ring_buffer_register(ring, 0);
+}
+
+void adis16350_uninitialize_ring(struct iio_ring_buffer *ring)
+{
+	iio_ring_buffer_unregister(ring);
+}