iio:gyro: Add support for the ADIS16136 gyroscope

This patch adds support for the ADIS16133, ADIS16135, ADIS16136 single channel
gyroscopes. The main difference between them is the sensor precision.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 591 insertions, 0 deletions

diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig
index 21e27e2fc68..48ed1483ff2 100644
--- a/drivers/iio/gyro/Kconfig
+++ b/drivers/iio/gyro/Kconfig
@@ -3,6 +3,15 @@
 #
 menu "Digital gyroscope sensors"
 
+config ADIS16136
+	tristate "Analog devices ADIS16136 and similar gyroscopes driver"
+	depends on SPI_MASTER
+	select IIO_ADIS_LIB
+	select IIO_ADIS_LIB_BUFFER if IIO_BUFFER
+	help
+	  Say yes here to build support for the Analog Devices ADIS16133, ADIS16135,
+	  ADIS16136 gyroscope devices.
+
 config HID_SENSOR_GYRO_3D
 	depends on HID_SENSOR_HUB
 	select IIO_BUFFER
diff --git a/drivers/iio/gyro/Makefile b/drivers/iio/gyro/Makefile
index 8a895d9fcbc..702a058907e 100644
--- a/drivers/iio/gyro/Makefile
+++ b/drivers/iio/gyro/Makefile
@@ -2,4 +2,5 @@
 # Makefile for industrial I/O gyroscope sensor drivers
 #
 
+obj-$(CONFIG_ADIS16136) += adis16136.o
 obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o
diff --git a/drivers/iio/gyro/adis16136.c b/drivers/iio/gyro/adis16136.c
new file mode 100644
index 00000000000..05486dfd721
--- /dev/null
+++ b/drivers/iio/gyro/adis16136.c
@@ -0,0 +1,581 @@
+/*
+ * ADIS16133/ADIS16135/ADIS16136 gyroscope driver
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *   Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#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 <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/imu/adis.h>
+
+#include <linux/iio/iio.h>
+#include <linux/debugfs.h>
+
+#define ADIS16136_REG_FLASH_CNT		0x00
+#define ADIS16136_REG_TEMP_OUT		0x02
+#define ADIS16136_REG_GYRO_OUT2		0x04
+#define ADIS16136_REG_GYRO_OUT		0x06
+#define ADIS16136_REG_GYRO_OFF2		0x08
+#define ADIS16136_REG_GYRO_OFF		0x0A
+#define ADIS16136_REG_ALM_MAG1		0x10
+#define ADIS16136_REG_ALM_MAG2		0x12
+#define ADIS16136_REG_ALM_SAMPL1	0x14
+#define ADIS16136_REG_ALM_SAMPL2	0x16
+#define ADIS16136_REG_ALM_CTRL		0x18
+#define ADIS16136_REG_GPIO_CTRL		0x1A
+#define ADIS16136_REG_MSC_CTRL		0x1C
+#define ADIS16136_REG_SMPL_PRD		0x1E
+#define ADIS16136_REG_AVG_CNT		0x20
+#define ADIS16136_REG_DEC_RATE		0x22
+#define ADIS16136_REG_SLP_CTRL		0x24
+#define ADIS16136_REG_DIAG_STAT		0x26
+#define ADIS16136_REG_GLOB_CMD		0x28
+#define ADIS16136_REG_LOT1		0x32
+#define ADIS16136_REG_LOT2		0x34
+#define ADIS16136_REG_LOT3		0x36
+#define ADIS16136_REG_PROD_ID		0x38
+#define ADIS16136_REG_SERIAL_NUM	0x3A
+
+#define ADIS16136_DIAG_STAT_FLASH_UPDATE_FAIL	2
+#define ADIS16136_DIAG_STAT_SPI_FAIL		3
+#define ADIS16136_DIAG_STAT_SELF_TEST_FAIL	5
+#define ADIS16136_DIAG_STAT_FLASH_CHKSUM_FAIL	6
+
+#define ADIS16136_MSC_CTRL_MEMORY_TEST BIT(11)
+#define ADIS16136_MSC_CTRL_SELF_TEST BIT(10)
+
+struct adis16136_chip_info {
+	unsigned int precision;
+	unsigned int fullscale;
+};
+
+struct adis16136 {
+	const struct adis16136_chip_info *chip_info;
+
+	struct adis adis;
+};
+
+#ifdef CONFIG_DEBUG_FS
+
+static ssize_t adis16136_show_serial(struct file *file,
+		char __user *userbuf, size_t count, loff_t *ppos)
+{
+	struct adis16136 *adis16136 = file->private_data;
+	uint16_t lot1, lot2, lot3, serial;
+	char buf[20];
+	size_t len;
+	int ret;
+
+	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_SERIAL_NUM,
+		&serial);
+	if (ret < 0)
+		return ret;
+
+	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_LOT1, &lot1);
+	if (ret < 0)
+		return ret;
+
+	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_LOT2, &lot2);
+	if (ret < 0)
+		return ret;
+
+	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_LOT3, &lot3);
+	if (ret < 0)
+		return ret;
+
+	len = snprintf(buf, sizeof(buf), "%.4x%.4x%.4x-%.4x\n", lot1, lot2,
+		lot3, serial);
+
+	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
+}
+
+static const struct file_operations adis16136_serial_fops = {
+	.open = simple_open,
+	.read = adis16136_show_serial,
+	.llseek = default_llseek,
+	.owner = THIS_MODULE,
+};
+
+static int adis16136_show_product_id(void *arg, u64 *val)
+{
+	struct adis16136 *adis16136 = arg;
+	u16 prod_id;
+	int ret;
+
+	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_PROD_ID,
+		&prod_id);
+	if (ret < 0)
+		return ret;
+
+	*val = prod_id;
+
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(adis16136_product_id_fops,
+	adis16136_show_product_id, NULL, "%llu\n");
+
+static int adis16136_show_flash_count(void *arg, u64 *val)
+{
+	struct adis16136 *adis16136 = arg;
+	uint16_t flash_count;
+	int ret;
+
+	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_FLASH_CNT,
+		&flash_count);
+	if (ret < 0)
+		return ret;
+
+	*val = flash_count;
+
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(adis16136_flash_count_fops,
+	adis16136_show_flash_count, NULL, "%lld\n");
+
+static int adis16136_debugfs_init(struct iio_dev *indio_dev)
+{
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+
+	debugfs_create_file("serial_number", 0400, indio_dev->debugfs_dentry,
+		adis16136, &adis16136_serial_fops);
+	debugfs_create_file("product_id", 0400, indio_dev->debugfs_dentry,
+		adis16136, &adis16136_product_id_fops);
+	debugfs_create_file("flash_count", 0400, indio_dev->debugfs_dentry,
+		adis16136, &adis16136_flash_count_fops);
+
+	return 0;
+}
+
+#else
+
+static int adis16136_debugfs_init(struct iio_dev *indio_dev)
+{
+	return 0;
+}
+
+#endif
+
+static int adis16136_set_freq(struct adis16136 *adis16136, unsigned int freq)
+{
+	unsigned int t;
+
+	t = 32768 / freq;
+	if (t < 0xf)
+		t = 0xf;
+	else if (t > 0xffff)
+		t = 0xffff;
+	else
+		t--;
+
+	return adis_write_reg_16(&adis16136->adis, ADIS16136_REG_SMPL_PRD, t);
+}
+
+static int adis16136_get_freq(struct adis16136 *adis16136, unsigned int *freq)
+{
+	uint16_t t;
+	int ret;
+
+	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_SMPL_PRD, &t);
+	if (ret < 0)
+		return ret;
+
+	*freq = 32768 / (t + 1);
+
+	return 0;
+}
+
+static ssize_t adis16136_write_frequency(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+	long val;
+	int ret;
+
+	ret = kstrtol(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	if (val == 0)
+		return -EINVAL;
+
+	ret = adis16136_set_freq(adis16136, val);
+
+	return ret ? ret : len;
+}
+
+static ssize_t adis16136_read_frequency(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+	unsigned int freq;
+	int ret;
+
+	ret = adis16136_get_freq(adis16136, &freq);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d\n", freq);
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
+				  adis16136_read_frequency,
+				  adis16136_write_frequency);
+
+static const unsigned adis16136_3db_divisors[] = {
+	[0] = 2, /* Special case */
+	[1] = 6,
+	[2] = 12,
+	[3] = 25,
+	[4] = 50,
+	[5] = 100,
+	[6] = 200,
+	[7] = 200, /* Not a valid setting */
+};
+
+static int adis16136_set_filter(struct iio_dev *indio_dev, int val)
+{
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+	unsigned int freq;
+	int i, ret;
+
+	ret = adis16136_get_freq(adis16136, &freq);
+	if (ret < 0)
+		return ret;
+
+	for (i = ARRAY_SIZE(adis16136_3db_divisors) - 1; i >= 1; i--) {
+		if (freq / adis16136_3db_divisors[i] >= val)
+			break;
+	}
+
+	return adis_write_reg_16(&adis16136->adis, ADIS16136_REG_AVG_CNT, i);
+}
+
+static int adis16136_get_filter(struct iio_dev *indio_dev, int *val)
+{
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+	unsigned int freq;
+	uint16_t val16;
+	int ret;
+
+	mutex_lock(&indio_dev->mlock);
+
+	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_AVG_CNT, &val16);
+	if (ret < 0)
+		goto err_unlock;
+
+	ret = adis16136_get_freq(adis16136, &freq);
+	if (ret < 0)
+		goto err_unlock;
+
+	*val = freq / adis16136_3db_divisors[val16 & 0x07];
+
+err_unlock:
+	mutex_unlock(&indio_dev->mlock);
+
+	return ret ? ret : IIO_VAL_INT;
+}
+
+static int adis16136_read_raw(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int *val, int *val2, long info)
+{
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+	uint32_t val32;
+	int ret;
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		return adis_single_conversion(indio_dev, chan, 0, val);
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			*val = adis16136->chip_info->precision;
+			*val2 = (adis16136->chip_info->fullscale << 16);
+			return IIO_VAL_FRACTIONAL;
+		case IIO_TEMP:
+			*val = 10;
+			*val2 = 697000; /* 0.010697 degree Celsius */
+			return IIO_VAL_INT_PLUS_MICRO;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_CALIBBIAS:
+		ret = adis_read_reg_32(&adis16136->adis,
+			ADIS16136_REG_GYRO_OFF2, &val32);
+		if (ret < 0)
+			return ret;
+
+		*val = sign_extend32(val32, 31);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		return adis16136_get_filter(indio_dev, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int adis16136_write_raw(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int val, int val2, long info)
+{
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_CALIBBIAS:
+		return adis_write_reg_32(&adis16136->adis,
+			ADIS16136_REG_GYRO_OFF2, val);
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		return adis16136_set_filter(indio_dev, val);
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+enum {
+	ADIS16136_SCAN_GYRO,
+	ADIS16136_SCAN_TEMP,
+};
+
+static const struct iio_chan_spec adis16136_channels[] = {
+	{
+		.type = IIO_ANGL_VEL,
+		.modified = 1,
+		.channel2 = IIO_MOD_X,
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
+			IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT |
+			IIO_CHAN_INFO_SCALE_SHARED_BIT |
+			IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SEPARATE_BIT,
+		.address = ADIS16136_REG_GYRO_OUT2,
+		.scan_index = ADIS16136_SCAN_GYRO,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_BE,
+		},
+	}, {
+		.type = IIO_TEMP,
+		.indexed = 1,
+		.channel = 0,
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
+			IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
+		.address = ADIS16136_REG_TEMP_OUT,
+		.scan_index = ADIS16136_SCAN_TEMP,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_BE,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+static struct attribute *adis16136_attributes[] = {
+	&iio_dev_attr_sampling_frequency.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group adis16136_attribute_group = {
+	.attrs = adis16136_attributes,
+};
+
+static const struct iio_info adis16136_info = {
+	.driver_module = THIS_MODULE,
+	.attrs = &adis16136_attribute_group,
+	.read_raw = &adis16136_read_raw,
+	.write_raw = &adis16136_write_raw,
+	.update_scan_mode = adis_update_scan_mode,
+	.debugfs_reg_access = adis_debugfs_reg_access,
+};
+
+static int adis16136_stop_device(struct iio_dev *indio_dev)
+{
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+	int ret;
+
+	ret = adis_write_reg_16(&adis16136->adis, ADIS16136_REG_SLP_CTRL, 0xff);
+	if (ret)
+		dev_err(&indio_dev->dev,
+			"Could not power down device: %d\n", ret);
+
+	return ret;
+}
+
+static int adis16136_initial_setup(struct iio_dev *indio_dev)
+{
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+	unsigned int device_id;
+	uint16_t prod_id;
+	int ret;
+
+	ret = adis_initial_startup(&adis16136->adis);
+	if (ret)
+		return ret;
+
+	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_PROD_ID,
+		&prod_id);
+	if (ret)
+		return ret;
+
+	sscanf(indio_dev->name, "adis%u\n", &device_id);
+
+	if (prod_id != device_id)
+		dev_warn(&indio_dev->dev, "Device ID(%u) and product ID(%u) do not match.",
+				device_id, prod_id);
+
+	return 0;
+}
+
+static const char * const adis16136_status_error_msgs[] = {
+	[ADIS16136_DIAG_STAT_FLASH_UPDATE_FAIL] = "Flash update failed",
+	[ADIS16136_DIAG_STAT_SPI_FAIL] = "SPI failure",
+	[ADIS16136_DIAG_STAT_SELF_TEST_FAIL] = "Self test error",
+	[ADIS16136_DIAG_STAT_FLASH_CHKSUM_FAIL] = "Flash checksum error",
+};
+
+static const struct adis_data adis16136_data = {
+	.diag_stat_reg = ADIS16136_REG_DIAG_STAT,
+	.glob_cmd_reg = ADIS16136_REG_GLOB_CMD,
+	.msc_ctrl_reg = ADIS16136_REG_MSC_CTRL,
+
+	.self_test_mask = ADIS16136_MSC_CTRL_SELF_TEST,
+	.startup_delay = 80,
+
+	.read_delay = 10,
+	.write_delay = 10,
+
+	.status_error_msgs = adis16136_status_error_msgs,
+	.status_error_mask = BIT(ADIS16136_DIAG_STAT_FLASH_UPDATE_FAIL) |
+		BIT(ADIS16136_DIAG_STAT_SPI_FAIL) |
+		BIT(ADIS16136_DIAG_STAT_SELF_TEST_FAIL) |
+		BIT(ADIS16136_DIAG_STAT_FLASH_CHKSUM_FAIL),
+};
+
+enum adis16136_id {
+	ID_ADIS16133,
+	ID_ADIS16135,
+	ID_ADIS16136,
+};
+
+static const struct adis16136_chip_info adis16136_chip_info[] = {
+	[ID_ADIS16133] = {
+		.precision = IIO_DEGREE_TO_RAD(1200),
+		.fullscale = 24000,
+	},
+	[ID_ADIS16135] = {
+		.precision = IIO_DEGREE_TO_RAD(300),
+		.fullscale = 24000,
+	},
+	[ID_ADIS16136] = {
+		.precision = IIO_DEGREE_TO_RAD(450),
+		.fullscale = 24623,
+	},
+};
+
+static int adis16136_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct adis16136 *adis16136;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = iio_device_alloc(sizeof(*adis16136));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, indio_dev);
+
+	adis16136 = iio_priv(indio_dev);
+
+	adis16136->chip_info = &adis16136_chip_info[id->driver_data];
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->channels = adis16136_channels;
+	indio_dev->num_channels = ARRAY_SIZE(adis16136_channels);
+	indio_dev->info = &adis16136_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = adis_init(&adis16136->adis, indio_dev, spi, &adis16136_data);
+	if (ret)
+		goto error_free_dev;
+
+	ret = adis_setup_buffer_and_trigger(&adis16136->adis, indio_dev, NULL);
+	if (ret)
+		goto error_free_dev;
+
+	ret = adis16136_initial_setup(indio_dev);
+	if (ret)
+		goto error_cleanup_buffer;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_stop_device;
+
+	adis16136_debugfs_init(indio_dev);
+
+	return 0;
+
+error_stop_device:
+	adis16136_stop_device(indio_dev);
+error_cleanup_buffer:
+	adis_cleanup_buffer_and_trigger(&adis16136->adis, indio_dev);
+error_free_dev:
+	iio_device_free(indio_dev);
+	return ret;
+}
+
+static int adis16136_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct adis16136 *adis16136 = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	adis16136_stop_device(indio_dev);
+
+	adis_cleanup_buffer_and_trigger(&adis16136->adis, indio_dev);
+
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct spi_device_id adis16136_ids[] = {
+	{ "adis16133", ID_ADIS16133 },
+	{ "adis16135", ID_ADIS16135 },
+	{ "adis16136", ID_ADIS16136 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, adis16136_ids);
+
+static struct spi_driver adis16136_driver = {
+	.driver = {
+		.name = "adis16136",
+		.owner = THIS_MODULE,
+	},
+	.id_table = adis16136_ids,
+	.probe = adis16136_probe,
+	.remove = adis16136_remove,
+};
+module_spi_driver(adis16136_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Analog Devices ADIS16133/ADIS16135/ADIS16136 gyroscope driver");
+MODULE_LICENSE("GPL v2");