iio:accel:kxsd9 move out of staging

This is a very simple driver giving basic access to this part over an
spi bus.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 299 insertions, 0 deletions

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 05e996f..d600353 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -14,4 +14,11 @@ config HID_SENSOR_ACCEL_3D
 	  Say yes here to build support for the HID SENSOR
 	  accelerometers 3D.
 
+config KXSD9
+	tristate "Kionix KXSD9 Accelerometer Driver"
+	depends on SPI
+	help
+	  Say yes here to build support for the Kionix KXSD9 accelerometer.
+	  Currently this only supports the device via an SPI interface.
+
 endmenu
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 5bc6855..4e1c859 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
+obj-$(CONFIG_KXSD9)	+= kxsd9.o
diff --git a/drivers/iio/accel/kxsd9.c b/drivers/iio/accel/kxsd9.c
new file mode 100644
index 0000000..4a24c2e
--- /dev/null
+++ b/drivers/iio/accel/kxsd9.c
@@ -0,0 +1,291 @@
+/*
+ * kxsd9.c	simple support for the Kionix KXSD9 3D
+ *		accelerometer.
+ *
+ * Copyright (c) 2008-2009 Jonathan Cameron <jic23@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * The i2c interface is very similar, so shouldn't be a problem once
+ * I have a suitable wire made up.
+ *
+ * TODO:	Support the motion detector
+ *		Uses register address incrementing so could have a
+ *		heavily optimized ring buffer access function.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define KXSD9_REG_X		0x00
+#define KXSD9_REG_Y		0x02
+#define KXSD9_REG_Z		0x04
+#define KXSD9_REG_AUX		0x06
+#define KXSD9_REG_RESET		0x0a
+#define KXSD9_REG_CTRL_C	0x0c
+
+#define KXSD9_FS_MASK		0x03
+
+#define KXSD9_REG_CTRL_B	0x0d
+#define KXSD9_REG_CTRL_A	0x0e
+
+#define KXSD9_READ(a) (0x80 | (a))
+#define KXSD9_WRITE(a) (a)
+
+#define KXSD9_STATE_RX_SIZE 2
+#define KXSD9_STATE_TX_SIZE 2
+/**
+ * struct kxsd9_state - device related storage
+ * @buf_lock:	protect the rx and tx buffers.
+ * @us:		spi device
+ * @rx:		single rx buffer storage
+ * @tx:		single tx buffer storage
+ **/
+struct kxsd9_state {
+	struct mutex buf_lock;
+	struct spi_device *us;
+	u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned;
+	u8 tx[KXSD9_STATE_TX_SIZE];
+};
+
+#define KXSD9_SCALE_2G "0.011978"
+#define KXSD9_SCALE_4G "0.023927"
+#define KXSD9_SCALE_6G "0.035934"
+#define KXSD9_SCALE_8G "0.047853"
+
+/* reverse order */
+static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 };
+
+static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
+{
+	int ret, i;
+	struct kxsd9_state *st = iio_priv(indio_dev);
+	bool foundit = false;
+
+	for (i = 0; i < 4; i++)
+		if (micro == kxsd9_micro_scales[i]) {
+			foundit = true;
+			break;
+		}
+	if (!foundit)
+		return -EINVAL;
+
+	mutex_lock(&st->buf_lock);
+	ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
+	if (ret)
+		goto error_ret;
+	st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
+	st->tx[1] = (ret & ~KXSD9_FS_MASK) | i;
+
+	ret = spi_write(st->us, st->tx, 2);
+error_ret:
+	mutex_unlock(&st->buf_lock);
+	return ret;
+}
+
+static int kxsd9_read(struct iio_dev *indio_dev, u8 address)
+{
+	struct spi_message msg;
+	int ret;
+	struct kxsd9_state *st = iio_priv(indio_dev);
+	struct spi_transfer xfers[] = {
+		{
+			.bits_per_word = 8,
+			.len = 1,
+			.delay_usecs = 200,
+			.tx_buf = st->tx,
+		}, {
+			.bits_per_word = 8,
+			.len = 2,
+			.rx_buf = st->rx,
+		},
+	};
+
+	mutex_lock(&st->buf_lock);
+	st->tx[0] = KXSD9_READ(address);
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfers[0], &msg);
+	spi_message_add_tail(&xfers[1], &msg);
+	ret = spi_sync(st->us, &msg);
+	if (ret)
+		return ret;
+	return (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
+}
+
+static IIO_CONST_ATTR(accel_scale_available,
+		KXSD9_SCALE_2G " "
+		KXSD9_SCALE_4G " "
+		KXSD9_SCALE_6G " "
+		KXSD9_SCALE_8G);
+
+static struct attribute *kxsd9_attributes[] = {
+	&iio_const_attr_accel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static int kxsd9_write_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int val,
+			   int val2,
+			   long mask)
+{
+	int ret = -EINVAL;
+
+	if (mask == IIO_CHAN_INFO_SCALE) {
+		/* Check no integer component */
+		if (val)
+			return -EINVAL;
+		ret = kxsd9_write_scale(indio_dev, val2);
+	}
+
+	return ret;
+}
+
+static int kxsd9_read_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan,
+			  int *val, int *val2, long mask)
+{
+	int ret = -EINVAL;
+	struct kxsd9_state *st = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = kxsd9_read(indio_dev, chan->address);
+		if (ret < 0)
+			goto error_ret;
+		*val = ret;
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
+		if (ret)
+			goto error_ret;
+		*val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
+		ret = IIO_VAL_INT_PLUS_MICRO;
+		break;
+	}
+
+error_ret:
+	return ret;
+};
+#define KXSD9_ACCEL_CHAN(axis)						\
+	{								\
+		.type = IIO_ACCEL,					\
+		.modified = 1,						\
+		.channel2 = IIO_MOD_##axis,				\
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |		\
+			IIO_CHAN_INFO_SCALE_SHARED_BIT,			\
+		.address = KXSD9_REG_##axis,				\
+	}
+
+static const struct iio_chan_spec kxsd9_channels[] = {
+	KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
+	{
+		.type = IIO_VOLTAGE,
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT,
+		.indexed = 1,
+		.address = KXSD9_REG_AUX,
+	}
+};
+
+static const struct attribute_group kxsd9_attribute_group = {
+	.attrs = kxsd9_attributes,
+};
+
+static int kxsd9_power_up(struct kxsd9_state *st)
+{
+	int ret;
+
+	st->tx[0] = 0x0d;
+	st->tx[1] = 0x40;
+	ret = spi_write(st->us, st->tx, 2);
+	if (ret)
+		return ret;
+
+	st->tx[0] = 0x0c;
+	st->tx[1] = 0x9b;
+	return spi_write(st->us, st->tx, 2);
+};
+
+static const struct iio_info kxsd9_info = {
+	.read_raw = &kxsd9_read_raw,
+	.write_raw = &kxsd9_write_raw,
+	.attrs = &kxsd9_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
+static int kxsd9_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct kxsd9_state *st;
+	int ret;
+
+	indio_dev = iio_device_alloc(sizeof(*st));
+	if (indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+	st = iio_priv(indio_dev);
+	spi_set_drvdata(spi, indio_dev);
+
+	st->us = spi;
+	mutex_init(&st->buf_lock);
+	indio_dev->channels = kxsd9_channels;
+	indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->info = &kxsd9_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	spi->mode = SPI_MODE_0;
+	spi_setup(spi);
+	kxsd9_power_up(st);
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_free_dev;
+
+	return 0;
+
+error_free_dev:
+	iio_device_free(indio_dev);
+error_ret:
+	return ret;
+}
+
+static int kxsd9_remove(struct spi_device *spi)
+{
+	iio_device_unregister(spi_get_drvdata(spi));
+	iio_device_free(spi_get_drvdata(spi));
+
+	return 0;
+}
+
+static const struct spi_device_id kxsd9_id[] = {
+	{"kxsd9", 0},
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, kxsd9_id);
+
+static struct spi_driver kxsd9_driver = {
+	.driver = {
+		.name = "kxsd9",
+		.owner = THIS_MODULE,
+	},
+	.probe = kxsd9_probe,
+	.remove = kxsd9_remove,
+	.id_table = kxsd9_id,
+};
+module_spi_driver(kxsd9_driver);
+
+MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
+MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
+MODULE_LICENSE("GPL v2");