1 files changed, 448 insertions, 0 deletions
diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
new file mode 100644
index 000000000..c771ae680
--- /dev/null
+++ b/drivers/iio/imu/adis.c
@@ -0,0 +1,448 @@
+/*
+ * 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)
+
+int adis_write_reg(struct adis *adis, unsigned int reg,
+	unsigned int value, unsigned int size)
+{
+	unsigned int page = reg / ADIS_PAGE_SIZE;
+	int ret, i;
+	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,
+			.cs_change = 1,
+			.delay_usecs = adis->data->write_delay,
+		}, {
+			.tx_buf = adis->tx + 4,
+			.bits_per_word = 8,
+			.len = 2,
+			.cs_change = 1,
+			.delay_usecs = adis->data->write_delay,
+		}, {
+			.tx_buf = adis->tx + 6,
+			.bits_per_word = 8,
+			.len = 2,
+			.delay_usecs = adis->data->write_delay,
+		}, {
+			.tx_buf = adis->tx + 8,
+			.bits_per_word = 8,
+			.len = 2,
+			.delay_usecs = adis->data->write_delay,
+		},
+	};
+
+	mutex_lock(&adis->txrx_lock);
+
+	spi_message_init(&msg);
+
+	if (adis->current_page != page) {
+		adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
+		adis->tx[1] = page;
+		spi_message_add_tail(&xfers[0], &msg);
+	}
+
+	switch (size) {
+	case 4:
+		adis->tx[8] = ADIS_WRITE_REG(reg + 3);
+		adis->tx[9] = (value >> 24) & 0xff;
+		adis->tx[6] = ADIS_WRITE_REG(reg + 2);
+		adis->tx[7] = (value >> 16) & 0xff;
+		/* fall through */
+	case 2:
+		adis->tx[4] = ADIS_WRITE_REG(reg + 1);
+		adis->tx[5] = (value >> 8) & 0xff;
+		/* fall through */
+	case 1:
+		adis->tx[2] = ADIS_WRITE_REG(reg);
+		adis->tx[3] = value & 0xff;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	xfers[size].cs_change = 0;
+
+	for (i = 1; i <= size; i++)
+		spi_message_add_tail(&xfers[i], &msg);
+
+	ret = spi_sync(adis->spi, &msg);
+	if (ret) {
+		dev_err(&adis->spi->dev, "Failed to write register 0x%02X: %d\n",
+				reg, ret);
+	} else {
+		adis->current_page = page;
+	}
+
+out_unlock:
+	mutex_unlock(&adis->txrx_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(adis_write_reg);
+
+/**
+ * adis_read_reg() - 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(struct adis *adis, unsigned int reg,
+	unsigned int *val, unsigned int size)
+{
+	unsigned int page = reg / ADIS_PAGE_SIZE;
+	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->write_delay,
+		}, {
+			.tx_buf = adis->tx + 2,
+			.bits_per_word = 8,
+			.len = 2,
+			.cs_change = 1,
+			.delay_usecs = adis->data->read_delay,
+		}, {
+			.tx_buf = adis->tx + 4,
+			.rx_buf = adis->rx,
+			.bits_per_word = 8,
+			.len = 2,
+			.cs_change = 1,
+			.delay_usecs = adis->data->read_delay,
+		}, {
+			.rx_buf = adis->rx + 2,
+			.bits_per_word = 8,
+			.len = 2,
+			.delay_usecs = adis->data->read_delay,
+		},
+	};
+
+	mutex_lock(&adis->txrx_lock);
+	spi_message_init(&msg);
+
+	if (adis->current_page != page) {
+		adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
+		adis->tx[1] = page;
+		spi_message_add_tail(&xfers[0], &msg);
+	}
+
+	switch (size) {
+	case 4:
+		adis->tx[2] = ADIS_READ_REG(reg + 2);
+		adis->tx[3] = 0;
+		spi_message_add_tail(&xfers[1], &msg);
+		/* fall through */
+	case 2:
+		adis->tx[4] = ADIS_READ_REG(reg);
+		adis->tx[5] = 0;
+		spi_message_add_tail(&xfers[2], &msg);
+		spi_message_add_tail(&xfers[3], &msg);
+		break;
+	default:
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	ret = spi_sync(adis->spi, &msg);
+	if (ret) {
+		dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n",
+				reg, ret);
+		goto out_unlock;
+	} else {
+		adis->current_page = page;
+	}
+
+	switch (size) {
+	case 4:
+		*val = get_unaligned_be32(adis->rx);
+		break;
+	case 2:
+		*val = get_unaligned_be16(adis->rx + 2);
+		break;
+	}
+
+out_unlock:
+	mutex_unlock(&adis->txrx_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(adis_read_reg);
+
+#ifdef CONFIG_DEBUG_FS
+
+int adis_debugfs_reg_access(struct iio_dev *indio_dev,
+	unsigned int reg, unsigned int writeval, unsigned int *readval)
+{
+	struct adis *adis = iio_device_get_drvdata(indio_dev);
+
+	if (readval) {
+		uint16_t val16;
+		int ret;
+
+		ret = adis_read_reg_16(adis, reg, &val16);
+		*readval = val16;
+
+		return ret;
+	} else {
+		return adis_write_reg_16(adis, reg, writeval);
+	}
+}
+EXPORT_SYMBOL(adis_debugfs_reg_access);
+
+#endif
+
+/**
+ * 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;
+
+	if (adis->data->enable_irq)
+		return adis->data->enable_irq(adis, enable);
+
+	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);
+
+	ret = adis_check_status(adis);
+
+	if (adis->data->self_test_no_autoclear)
+		adis_write_reg_16(adis, adis->data->msc_ctrl_reg, 0x00);
+
+	return ret;
+}
+
+/**
+ * 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);
+	unsigned int uval;
+	int ret;
+
+	mutex_lock(&indio_dev->mlock);
+
+	ret = adis_read_reg(adis, chan->address, &uval,
+			chan->scan_type.storagebits / 8);
+	if (ret)
+		goto err_unlock;
+
+	if (uval & error_mask) {
+		ret = adis_check_status(adis);
+		if (ret)
+			goto err_unlock;
+	}
+
+	if (chan->scan_type.sign == 's')
+		*val = sign_extend32(uval, chan->scan_type.realbits - 1);
+	else
+		*val = uval & ((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);
+
+	if (data->has_paging) {
+		/* Need to set the page before first read/write */
+		adis->current_page = -1;
+	} else {
+		/* Page will always be 0 */
+		adis->current_page = 0;
+	}
+
+	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");