1 files changed, 337 insertions, 0 deletions
diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
new file mode 100644
index 000000000000..8259b774078f
--- /dev/null
+++ b/drivers/iio/imu/adis.c
@@ -0,0 +1,337 @@
+/*
+ * Common library for ADIS16XXX devices
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *   Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/module.h>
+#include <asm/unaligned.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/imu/adis.h>
+
+#define ADIS_MSC_CTRL_DATA_RDY_EN	BIT(2)
+#define ADIS_MSC_CTRL_DATA_RDY_POL_HIGH	BIT(1)
+#define ADIS_MSC_CTRL_DATA_RDY_DIO2	BIT(0)
+#define ADIS_GLOB_CMD_SW_RESET		BIT(7)
+
+/**
+ * adis_write_reg_8() - Write single byte to a register
+ * @adis: The adis device
+ * @reg: The address of the register to be written
+ * @val: The value to write
+ */
+int adis_write_reg_8(struct adis *adis, unsigned int reg, uint8_t val)
+{
+	int ret;
+
+	mutex_lock(&adis->txrx_lock);
+	adis->tx[0] = ADIS_WRITE_REG(reg);
+	adis->tx[1] = val;
+
+	ret = spi_write(adis->spi, adis->tx, 2);
+	mutex_unlock(&adis->txrx_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(adis_write_reg_8);
+
+/**
+ * adis_write_reg_16() - Write 2 bytes to a pair of registers
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @val: Value to be written
+ */
+int adis_write_reg_16(struct adis *adis, unsigned int reg, uint16_t value)
+{
+	int ret;
+	struct spi_message msg;
+	struct spi_transfer xfers[] = {
+		{
+			.tx_buf = adis->tx,
+			.bits_per_word = 8,
+			.len = 2,
+			.cs_change = 1,
+			.delay_usecs = adis->data->write_delay,
+		}, {
+			.tx_buf = adis->tx + 2,
+			.bits_per_word = 8,
+			.len = 2,
+			.delay_usecs = adis->data->write_delay,
+		},
+	};
+
+	mutex_lock(&adis->txrx_lock);
+	adis->tx[0] = ADIS_WRITE_REG(reg);
+	adis->tx[1] = value & 0xff;
+	adis->tx[2] = ADIS_WRITE_REG(reg + 1);
+	adis->tx[3] = (value >> 8) & 0xff;
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfers[0], &msg);
+	spi_message_add_tail(&xfers[1], &msg);
+	ret = spi_sync(adis->spi, &msg);
+	mutex_unlock(&adis->txrx_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(adis_write_reg_16);
+
+/**
+ * adis_read_reg_16() - read 2 bytes from a 16-bit register
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @val: The value read back from the device
+ */
+int adis_read_reg_16(struct adis *adis, unsigned int reg, uint16_t *val)
+{
+	struct spi_message msg;
+	int ret;
+	struct spi_transfer xfers[] = {
+		{
+			.tx_buf = adis->tx,
+			.bits_per_word = 8,
+			.len = 2,
+			.cs_change = 1,
+			.delay_usecs = adis->data->read_delay,
+		}, {
+			.rx_buf = adis->rx,
+			.bits_per_word = 8,
+			.len = 2,
+			.delay_usecs = adis->data->read_delay,
+		},
+	};
+
+	mutex_lock(&adis->txrx_lock);
+	adis->tx[0] = ADIS_READ_REG(reg);
+	adis->tx[1] = 0;
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfers[0], &msg);
+	spi_message_add_tail(&xfers[1], &msg);
+	ret = spi_sync(adis->spi, &msg);
+	if (ret) {
+		dev_err(&adis->spi->dev, "Failed to read 16 bit register 0x%02X: %d\n",
+				reg, ret);
+		goto error_ret;
+	}
+	*val = get_unaligned_be16(adis->rx);
+
+error_ret:
+	mutex_unlock(&adis->txrx_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(adis_read_reg_16);
+
+/**
+ * adis_enable_irq() - Enable or disable data ready IRQ
+ * @adis: The adis device
+ * @enable: Whether to enable the IRQ
+ *
+ * Returns 0 on success, negative error code otherwise
+ */
+int adis_enable_irq(struct adis *adis, bool enable)
+{
+	int ret = 0;
+	uint16_t msc;
+
+	ret = adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc);
+	if (ret)
+		goto error_ret;
+
+	msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH;
+	msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2;
+	if (enable)
+		msc |= ADIS_MSC_CTRL_DATA_RDY_EN;
+	else
+		msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN;
+
+	ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc);
+
+error_ret:
+	return ret;
+}
+EXPORT_SYMBOL(adis_enable_irq);
+
+/**
+ * adis_check_status() - Check the device for error conditions
+ * @adis: The adis device
+ *
+ * Returns 0 on success, a negative error code otherwise
+ */
+int adis_check_status(struct adis *adis)
+{
+	uint16_t status;
+	int ret;
+	int i;
+
+	ret = adis_read_reg_16(adis, adis->data->diag_stat_reg, &status);
+	if (ret < 0)
+		return ret;
+
+	status &= adis->data->status_error_mask;
+
+	if (status == 0)
+		return 0;
+
+	for (i = 0; i < 16; ++i) {
+		if (status & BIT(i)) {
+			dev_err(&adis->spi->dev, "%s.\n",
+				adis->data->status_error_msgs[i]);
+		}
+	}
+
+	return -EIO;
+}
+EXPORT_SYMBOL_GPL(adis_check_status);
+
+/**
+ * adis_reset() - Reset the device
+ * @adis: The adis device
+ *
+ * Returns 0 on success, a negative error code otherwise
+ */
+int adis_reset(struct adis *adis)
+{
+	int ret;
+
+	ret = adis_write_reg_8(adis, adis->data->glob_cmd_reg,
+			ADIS_GLOB_CMD_SW_RESET);
+	if (ret)
+		dev_err(&adis->spi->dev, "Failed to reset device: %d\n", ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(adis_reset);
+
+static int adis_self_test(struct adis *adis)
+{
+	int ret;
+
+	ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg,
+			adis->data->self_test_mask);
+	if (ret) {
+		dev_err(&adis->spi->dev, "Failed to initiate self test: %d\n",
+			ret);
+		return ret;
+	}
+
+	msleep(adis->data->startup_delay);
+
+	return adis_check_status(adis);
+}
+
+/**
+ * adis_inital_startup() - Performs device self-test
+ * @adis: The adis device
+ *
+ * Returns 0 if the device is operational, a negative error code otherwise.
+ *
+ * This function should be called early on in the device initialization sequence
+ * to ensure that the device is in a sane and known state and that it is usable.
+ */
+int adis_initial_startup(struct adis *adis)
+{
+	int ret;
+
+	ret = adis_self_test(adis);
+	if (ret) {
+		dev_err(&adis->spi->dev, "Self-test failed, trying reset.\n");
+		adis_reset(adis);
+		msleep(adis->data->startup_delay);
+		ret = adis_self_test(adis);
+		if (ret) {
+			dev_err(&adis->spi->dev, "Second self-test failed, giving up.\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(adis_initial_startup);
+
+/**
+ * adis_single_conversion() - Performs a single sample conversion
+ * @indio_dev: The IIO device
+ * @chan: The IIO channel
+ * @error_mask: Mask for the error bit
+ * @val: Result of the conversion
+ *
+ * Returns IIO_VAL_INT on success, a negative error code otherwise.
+ *
+ * The function performs a single conversion on a given channel and post
+ * processes the value accordingly to the channel spec. If a error_mask is given
+ * the function will check if the mask is set in the returned raw value. If it
+ * is set the function will perform a self-check. If the device does not report
+ * a error bit in the channels raw value set error_mask to 0.
+ */
+int adis_single_conversion(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, unsigned int error_mask, int *val)
+{
+	struct adis *adis = iio_device_get_drvdata(indio_dev);
+	uint16_t val16;
+	int ret;
+
+	mutex_lock(&indio_dev->mlock);
+
+	ret = adis_read_reg_16(adis, chan->address, &val16);
+	if (ret)
+		goto err_unlock;
+
+	if (val16 & error_mask) {
+		ret = adis_check_status(adis);
+		if (ret)
+			goto err_unlock;
+	}
+
+	if (chan->scan_type.sign == 's')
+		*val = sign_extend32(val16, chan->scan_type.realbits - 1);
+	else
+		*val = val16 & ((1 << chan->scan_type.realbits) - 1);
+
+	ret = IIO_VAL_INT;
+err_unlock:
+	mutex_unlock(&indio_dev->mlock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(adis_single_conversion);
+
+/**
+ * adis_init() - Initialize adis device structure
+ * @adis:	The adis device
+ * @indio_dev:	The iio device
+ * @spi:	The spi device
+ * @data:	Chip specific data
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ *
+ * This function must be called, before any other adis helper function may be
+ * called.
+ */
+int adis_init(struct adis *adis, struct iio_dev *indio_dev,
+	struct spi_device *spi, const struct adis_data *data)
+{
+	mutex_init(&adis->txrx_lock);
+	adis->spi = spi;
+	adis->data = data;
+	iio_device_set_drvdata(indio_dev, adis);
+
+	return adis_enable_irq(adis, false);
+}
+EXPORT_SYMBOL_GPL(adis_init);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Common library code for ADIS16XXX devices");