iio: gyro: Add itg3200

This patch adds support for the InvenSense itg3200.
The itg3200 is a three-axis gyro with 16-bit ADC and
I2C interface.

Signed-off-by: Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

4 files changed, 569 insertions, 0 deletions

diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig
index 51ac6bc791c6..6be4628faffe 100644
--- a/drivers/iio/gyro/Kconfig
+++ b/drivers/iio/gyro/Kconfig
@@ -70,4 +70,12 @@ config IIO_ST_GYRO_SPI_3AXIS
         depends on IIO_ST_GYRO_3AXIS
         depends on IIO_ST_SENSORS_SPI
 
+config ITG3200
+        tristate "InvenSense ITG3200 Digital 3-Axis Gyroscope I2C driver"
+        depends on I2C
+        select IIO_TRIGGERED_BUFFER if IIO_BUFFER
+        help
+          Say yes here to add support for the InvenSense ITG3200 digital
+          3-axis gyroscope sensor.
+
 endmenu
diff --git a/drivers/iio/gyro/Makefile b/drivers/iio/gyro/Makefile
index eff9bb0119a2..225d289082e6 100644
--- a/drivers/iio/gyro/Makefile
+++ b/drivers/iio/gyro/Makefile
@@ -8,6 +8,10 @@ obj-$(CONFIG_ADXRS450) += adxrs450.o
 
 obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o
 
+itg3200-y               := itg3200_core.o
+itg3200-$(CONFIG_IIO_BUFFER) += itg3200_buffer.o
+obj-$(CONFIG_ITG3200)   += itg3200.o
+
 obj-$(CONFIG_IIO_ST_GYRO_3AXIS) += st_gyro.o
 st_gyro-y := st_gyro_core.o
 st_gyro-$(CONFIG_IIO_BUFFER) += st_gyro_buffer.o
diff --git a/drivers/iio/gyro/itg3200_buffer.c b/drivers/iio/gyro/itg3200_buffer.c
new file mode 100644
index 000000000000..f667d2c8c00f
--- /dev/null
+++ b/drivers/iio/gyro/itg3200_buffer.c
@@ -0,0 +1,156 @@
+/*
+ * itg3200_buffer.c -- support InvenSense ITG3200
+ *                     Digital 3-Axis Gyroscope driver
+ *
+ * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de>
+ * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
+ * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
+ *
+ * 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.
+ */
+
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/gyro/itg3200.h>
+
+
+static int itg3200_read_all_channels(struct i2c_client *i2c, __be16 *buf)
+{
+        u8 tx = 0x80 | ITG3200_REG_TEMP_OUT_H;
+        struct i2c_msg msg[2] = {
+                {
+                        .addr = i2c->addr,
+                        .flags = i2c->flags,
+                        .len = 1,
+                        .buf = &tx,
+                },
+                {
+                        .addr = i2c->addr,
+                        .flags = i2c->flags | I2C_M_RD,
+                        .len = ITG3200_SCAN_ELEMENTS * sizeof(s16),
+                        .buf = (char *)&buf,
+                },
+        };
+
+        return i2c_transfer(i2c->adapter, msg, 2);
+}
+
+static irqreturn_t itg3200_trigger_handler(int irq, void *p)
+{
+        struct iio_poll_func *pf = p;
+        struct iio_dev *indio_dev = pf->indio_dev;
+        struct itg3200 *st = iio_priv(indio_dev);
+        __be16 buf[ITG3200_SCAN_ELEMENTS + sizeof(s64)/sizeof(u16)];
+
+        int ret = itg3200_read_all_channels(st->i2c, buf);
+        if (ret < 0)
+                goto error_ret;
+
+        if (indio_dev->scan_timestamp)
+                memcpy(buf + indio_dev->scan_bytes - sizeof(s64),
+                                &pf->timestamp, sizeof(pf->timestamp));
+
+        iio_push_to_buffers(indio_dev, (u8 *)buf);
+        iio_trigger_notify_done(indio_dev->trig);
+
+error_ret:
+        return IRQ_HANDLED;
+}
+
+int itg3200_buffer_configure(struct iio_dev *indio_dev)
+{
+        return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+                itg3200_trigger_handler, NULL);
+}
+
+void itg3200_buffer_unconfigure(struct iio_dev *indio_dev)
+{
+        iio_triggered_buffer_cleanup(indio_dev);
+}
+
+
+static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig,
+                bool state)
+{
+        struct iio_dev *indio_dev = trig->private_data;
+        int ret;
+        u8 msc;
+
+        ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc);
+        if (ret)
+                goto error_ret;
+
+        if (state)
+                msc |= ITG3200_IRQ_DATA_RDY_ENABLE;
+        else
+                msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE;
+
+        ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, msc);
+        if (ret)
+                goto error_ret;
+
+error_ret:
+        return ret;
+
+}
+
+static const struct iio_trigger_ops itg3200_trigger_ops = {
+        .owner = THIS_MODULE,
+        .set_trigger_state = &itg3200_data_rdy_trigger_set_state,
+};
+
+int itg3200_probe_trigger(struct iio_dev *indio_dev)
+{
+        int ret;
+        struct itg3200 *st = iio_priv(indio_dev);
+
+        st->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name,
+                                     indio_dev->id);
+        if (!st->trig)
+                return -ENOMEM;
+
+        ret = request_irq(st->i2c->irq,
+                          &iio_trigger_generic_data_rdy_poll,
+                          IRQF_TRIGGER_RISING,
+                          "itg3200_data_rdy",
+                          st->trig);
+        if (ret)
+                goto error_free_trig;
+
+
+        st->trig->dev.parent = &st->i2c->dev;
+        st->trig->ops = &itg3200_trigger_ops;
+        st->trig->private_data = indio_dev;
+        ret = iio_trigger_register(st->trig);
+        if (ret)
+                goto error_free_irq;
+
+        /* select default trigger */
+        indio_dev->trig = st->trig;
+
+        return 0;
+
+error_free_irq:
+        free_irq(st->i2c->irq, st->trig);
+error_free_trig:
+        iio_trigger_free(st->trig);
+        return ret;
+}
+
+void itg3200_remove_trigger(struct iio_dev *indio_dev)
+{
+        struct itg3200 *st = iio_priv(indio_dev);
+
+        iio_trigger_unregister(st->trig);
+        free_irq(st->i2c->irq, st->trig);
+        iio_trigger_free(st->trig);
+}
diff --git a/drivers/iio/gyro/itg3200_core.c b/drivers/iio/gyro/itg3200_core.c
new file mode 100644
index 000000000000..df2e6aa5d73b
--- /dev/null
+++ b/drivers/iio/gyro/itg3200_core.c
@@ -0,0 +1,401 @@
+/*
+ * itg3200_core.c -- support InvenSense ITG3200
+ *                   Digital 3-Axis Gyroscope driver
+ *
+ * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de>
+ * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
+ * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
+ *
+ * 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.
+ *
+ * TODO:
+ * - Support digital low pass filter
+ * - Support power management
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+#include <linux/iio/buffer.h>
+
+#include <linux/iio/gyro/itg3200.h>
+
+
+int itg3200_write_reg_8(struct iio_dev *indio_dev,
+                u8 reg_address, u8 val)
+{
+        struct itg3200 *st = iio_priv(indio_dev);
+
+        return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val);
+}
+
+int itg3200_read_reg_8(struct iio_dev *indio_dev,
+                u8 reg_address, u8 *val)
+{
+        struct itg3200 *st = iio_priv(indio_dev);
+        int ret;
+
+        ret = i2c_smbus_read_byte_data(st->i2c, reg_address);
+        if (ret < 0)
+                return ret;
+        *val = ret;
+        return 0;
+}
+
+static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address,
+                int *val)
+{
+        struct itg3200 *st = iio_priv(indio_dev);
+        struct i2c_client *client = st->i2c;
+        int ret;
+        s16 out;
+
+        struct i2c_msg msg[2] = {
+                {
+                        .addr = client->addr,
+                        .flags = client->flags,
+                        .len = 1,
+                        .buf = (char *)&lower_reg_address,
+                },
+                {
+                        .addr = client->addr,
+                        .flags = client->flags | I2C_M_RD,
+                        .len = 2,
+                        .buf = (char *)&out,
+                },
+        };
+
+        lower_reg_address |= 0x80;
+        ret = i2c_transfer(client->adapter, msg, 2);
+        be16_to_cpus(&out);
+        *val = out;
+
+        return (ret == 2) ? 0 : ret;
+}
+
+static int itg3200_read_raw(struct iio_dev *indio_dev,
+                const struct iio_chan_spec *chan,
+                int *val, int *val2, long info)
+{
+        int ret = 0;
+        u8 reg;
+
+        switch (info) {
+        case IIO_CHAN_INFO_RAW:
+                reg = (u8)chan->address;
+                ret = itg3200_read_reg_s16(indio_dev, reg, val);
+                return IIO_VAL_INT;
+        case IIO_CHAN_INFO_SCALE:
+                *val = 0;
+                if (chan->type == IIO_TEMP)
+                        *val2 = 1000000000/280;
+                else
+                        *val2 = 1214142; /* (1 / 14,375) * (PI / 180) */
+                return IIO_VAL_INT_PLUS_NANO;
+        case IIO_CHAN_INFO_OFFSET:
+                /* Only the temperature channel has an offset */
+                *val = 23000;
+                return IIO_VAL_INT;
+        default:
+                return -EINVAL;
+        }
+
+        return ret;
+}
+
+static ssize_t itg3200_read_frequency(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+        int ret, sps;
+        u8 val;
+
+        ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
+        if (ret)
+                return ret;
+
+        sps = (val & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
+
+        ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, &val);
+        if (ret)
+                return ret;
+
+        sps /= val + 1;
+
+        return sprintf(buf, "%d\n", sps);
+}
+
+static ssize_t itg3200_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);
+        unsigned val;
+        int ret;
+        u8 t;
+
+        ret = kstrtouint(buf, 10, &val);
+        if (ret)
+                return ret;
+
+        mutex_lock(&indio_dev->mlock);
+
+        ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
+        if (ret)
+                goto err_ret;
+
+        if (val == 0) {
+                ret = -EINVAL;
+                goto err_ret;
+        }
+        t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
+
+        ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, t);
+
+err_ret:
+        mutex_unlock(&indio_dev->mlock);
+
+        return ret ? ret : len;
+}
+
+/*
+ * Reset device and internal registers to the power-up-default settings
+ * Use the gyro clock as reference, as suggested by the datasheet
+ */
+static int itg3200_reset(struct iio_dev *indio_dev)
+{
+        struct itg3200 *st = iio_priv(indio_dev);
+        int ret;
+
+        dev_dbg(&st->i2c->dev, "reset device");
+
+        ret = itg3200_write_reg_8(indio_dev,
+                        ITG3200_REG_POWER_MANAGEMENT,
+                        ITG3200_RESET);
+        if (ret) {
+                dev_err(&st->i2c->dev, "error resetting device");
+                goto error_ret;
+        }
+
+        /* Wait for PLL (1ms according to datasheet) */
+        udelay(1500);
+
+        ret = itg3200_write_reg_8(indio_dev,
+                        ITG3200_REG_IRQ_CONFIG,
+                        ITG3200_IRQ_ACTIVE_HIGH |
+                        ITG3200_IRQ_PUSH_PULL |
+                        ITG3200_IRQ_LATCH_50US_PULSE |
+                        ITG3200_IRQ_LATCH_CLEAR_ANY);
+
+        if (ret)
+                dev_err(&st->i2c->dev, "error init device");
+
+error_ret:
+        return ret;
+}
+
+/* itg3200_enable_full_scale() - Disables the digital low pass filter */
+static int itg3200_enable_full_scale(struct iio_dev *indio_dev)
+{
+        u8 val;
+        int ret;
+
+        ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
+        if (ret)
+                goto err_ret;
+
+        val |= ITG3200_DLPF_FS_SEL_2000;
+        return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val);
+
+err_ret:
+        return ret;
+}
+
+static int itg3200_initial_setup(struct iio_dev *indio_dev)
+{
+        struct itg3200 *st = iio_priv(indio_dev);
+        int ret;
+        u8 val;
+
+        ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
+        if (ret)
+                goto err_ret;
+
+        if (((val >> 1) & 0x3f) != 0x34) {
+                dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val);
+                ret = -ENXIO;
+                goto err_ret;
+        }
+
+        ret = itg3200_reset(indio_dev);
+        if (ret)
+                goto err_ret;
+
+        ret = itg3200_enable_full_scale(indio_dev);
+err_ret:
+        return ret;
+}
+
+#define ITG3200_TEMP_INFO_MASK  (IIO_CHAN_INFO_OFFSET_SHARED_BIT | \
+                                 IIO_CHAN_INFO_SCALE_SHARED_BIT | \
+                                 IIO_CHAN_INFO_RAW_SEPARATE_BIT)
+#define ITG3200_GYRO_INFO_MASK  (IIO_CHAN_INFO_SCALE_SHARED_BIT | \
+                                 IIO_CHAN_INFO_RAW_SEPARATE_BIT)
+
+#define ITG3200_ST                                              \
+        { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE }
+
+#define ITG3200_GYRO_CHAN(_mod) { \
+        .type = IIO_ANGL_VEL, \
+        .modified = 1, \
+        .channel2 = IIO_MOD_ ## _mod, \
+        .info_mask = ITG3200_GYRO_INFO_MASK, \
+        .address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
+        .scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
+        .scan_type = ITG3200_ST, \
+}
+
+static const struct iio_chan_spec itg3200_channels[] = {
+        {
+                .type = IIO_TEMP,
+                .channel2 = IIO_NO_MOD,
+                .info_mask = ITG3200_TEMP_INFO_MASK,
+                .address = ITG3200_REG_TEMP_OUT_H,
+                .scan_index = ITG3200_SCAN_TEMP,
+                .scan_type = ITG3200_ST,
+        },
+        ITG3200_GYRO_CHAN(X),
+        ITG3200_GYRO_CHAN(Y),
+        ITG3200_GYRO_CHAN(Z),
+        IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
+};
+
+/* IIO device attributes */
+static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, itg3200_read_frequency,
+                itg3200_write_frequency);
+
+static struct attribute *itg3200_attributes[] = {
+        &iio_dev_attr_sampling_frequency.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group itg3200_attribute_group = {
+        .attrs = itg3200_attributes,
+};
+
+static const struct iio_info itg3200_info = {
+        .attrs = &itg3200_attribute_group,
+        .read_raw = &itg3200_read_raw,
+        .driver_module = THIS_MODULE,
+};
+
+static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 };
+
+static int itg3200_probe(struct i2c_client *client,
+                const struct i2c_device_id *id)
+{
+        int ret;
+        struct itg3200 *st;
+        struct iio_dev *indio_dev;
+
+        dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq);
+
+        indio_dev = iio_device_alloc(sizeof(*st));
+        if (indio_dev == NULL) {
+                ret =  -ENOMEM;
+                goto error_ret;
+        }
+
+        st = iio_priv(indio_dev);
+
+        i2c_set_clientdata(client, indio_dev);
+        st->i2c = client;
+
+        indio_dev->dev.parent = &client->dev;
+        indio_dev->name = client->dev.driver->name;
+        indio_dev->channels = itg3200_channels;
+        indio_dev->num_channels = ARRAY_SIZE(itg3200_channels);
+        indio_dev->available_scan_masks = itg3200_available_scan_masks;
+        indio_dev->info = &itg3200_info;
+        indio_dev->modes = INDIO_DIRECT_MODE;
+
+        ret = itg3200_buffer_configure(indio_dev);
+        if (ret)
+                goto error_free_dev;
+
+        if (client->irq) {
+                ret = itg3200_probe_trigger(indio_dev);
+                if (ret)
+                        goto error_unconfigure_buffer;
+        }
+
+        ret = itg3200_initial_setup(indio_dev);
+        if (ret)
+                goto error_remove_trigger;
+
+        ret = iio_device_register(indio_dev);
+        if (ret)
+                goto error_remove_trigger;
+
+        return 0;
+
+error_remove_trigger:
+        if (client->irq)
+                itg3200_remove_trigger(indio_dev);
+error_unconfigure_buffer:
+        itg3200_buffer_unconfigure(indio_dev);
+error_free_dev:
+        iio_device_free(indio_dev);
+error_ret:
+        return ret;
+}
+
+static int itg3200_remove(struct i2c_client *client)
+{
+        struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+        iio_device_unregister(indio_dev);
+
+        if (client->irq)
+                itg3200_remove_trigger(indio_dev);
+
+        itg3200_buffer_unconfigure(indio_dev);
+
+        iio_device_free(indio_dev);
+
+        return 0;
+}
+
+static const struct i2c_device_id itg3200_id[] = {
+        { "itg3200", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, itg3200_id);
+
+static struct i2c_driver itg3200_driver = {
+        .driver = {
+                .owner  = THIS_MODULE,
+                .name   = "itg3200",
+        },
+        .id_table       = itg3200_id,
+        .probe          = itg3200_probe,
+        .remove         = itg3200_remove,
+};
+
+module_i2c_driver(itg3200_driver);
+
+MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>");
+MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver");
+MODULE_LICENSE("GPL v2");