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 21e27e2fc68c..48ed1483ff27 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 8a895d9fcbce..702a058907e3 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 000000000000..05486dfd721b
--- /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");