[PATCH v4 6/6] iio: imu: kmx61: Add support for any motion trigger

From: Daniel Baluta
Date: Wed Dec 03 2014 - 08:48:12 EST

We use WUFE (Wake Up from Sleep Engine) and BTSE (Back to Sleep Engine)
to detect general motion input.

Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
---
drivers/iio/imu/kmx61.c | 433 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 426 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/imu/kmx61.c b/drivers/iio/imu/kmx61.c
index 0f6816a..972424b 100644
--- a/drivers/iio/imu/kmx61.c
+++ b/drivers/iio/imu/kmx61.c
@@ -20,6 +20,7 @@
#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
#include <linux/iio/trigger.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
@@ -30,6 +31,8 @@
#define KMX61_IRQ_NAME "kmx61_event"

#define KMX61_REG_WHO_AM_I 0x00
+#define KMX61_REG_INS1 0x01
+#define KMX61_REG_INS2 0x02

/*
* three 16-bit accelerometer output registers for X/Y/Z axis
@@ -63,20 +66,36 @@
#define KMX61_REG_INL 0x28
#define KMX61_REG_STBY 0x29
#define KMX61_REG_CTRL1 0x2A
+#define KMX61_REG_CTRL2 0x2B
#define KMX61_REG_ODCNTL 0x2C
#define KMX61_REG_INC1 0x2D

+#define KMX61_REG_WUF_THRESH 0x3D
+#define KMX61_REG_WUF_TIMER 0x3E
+
#define KMX61_ACC_STBY_BIT BIT(0)
#define KMX61_MAG_STBY_BIT BIT(1)
#define KMX61_ACT_STBY_BIT BIT(7)

#define KMX61_ALL_STBY (KMX61_ACC_STBY_BIT | KMX61_MAG_STBY_BIT)

+#define KMX61_REG_INS1_BIT_WUFS BIT(1)
+
+#define KMX61_REG_INS2_BIT_ZP BIT(0)
+#define KMX61_REG_INS2_BIT_ZN BIT(1)
+#define KMX61_REG_INS2_BIT_YP BIT(2)
+#define KMX61_REG_INS2_BIT_YN BIT(3)
+#define KMX61_REG_INS2_BIT_XP BIT(4)
+#define KMX61_REG_INS2_BIT_XN BIT(5)
+
#define KMX61_REG_CTRL1_GSEL_MASK 0x03

#define KMX61_REG_CTRL1_BIT_RES BIT(4)
#define KMX61_REG_CTRL1_BIT_DRDYE BIT(5)
+#define KMX61_REG_CTRL1_BIT_WUFE BIT(6)
+#define KMX61_REG_CTRL1_BIT_BTSE BIT(7)

+#define KMX61_REG_INC1_BIT_WUFS BIT(0)
#define KMX61_REG_INC1_BIT_DRDYM BIT(1)
#define KMX61_REG_INC1_BIT_DRDYA BIT(2)
#define KMX61_REG_INC1_BIT_IEN BIT(5)
@@ -86,6 +105,11 @@
#define KMX61_ACC_ODR_MASK 0x0F
#define KMX61_MAG_ODR_MASK 0xF0

+#define KMX61_OWUF_MASK 0x7
+
+#define KMX61_DEFAULT_WAKE_THRESH 1
+#define KMX61_DEFAULT_WAKE_DURATION 1
+
#define KMX61_SLEEP_DELAY_MS 2000

#define KMX61_CHIP_ID 0x12
@@ -111,11 +135,16 @@ struct kmx61_data {
/* config bits */
u8 range;
u8 odr_bits;
+ u8 wake_thresh;
+ u8 wake_duration;

/* accelerometer specific data */
struct iio_dev *acc_indio_dev;
struct iio_trigger *acc_dready_trig;
+ struct iio_trigger *motion_trig;
bool acc_dready_trig_on;
+ bool motion_trig_on;
+ bool ev_enable_state;

/* magnetometer specific data */
struct iio_dev *mag_indio_dev;
@@ -154,6 +183,23 @@ static const struct {
{3, 125000, 0x0A},
{6, 250000, 0x0B} };

+static const struct {
+ int val;
+ int val2;
+ int odr_bits;
+} kmx61_wake_up_odr_table[] = { {0, 781000, 0x00},
+ {1, 563000, 0x01},
+ {3, 125000, 0x02},
+ {6, 250000, 0x03},
+ {12, 500000, 0x04},
+ {25, 0, 0x05},
+ {50, 0, 0x06},
+ {100, 0, 0x06},
+ {200, 0, 0x06},
+ {400, 0, 0x06},
+ {800, 0, 0x06},
+ {1600, 0, 0x06} };
+
static IIO_CONST_ATTR(accel_scale_available, "0.009582 0.019163 0.038326");
static IIO_CONST_ATTR(magn_scale_available, "0.001465");
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
@@ -179,6 +225,14 @@ static const struct attribute_group kmx61_mag_attribute_group = {
.attrs = kmx61_mag_attributes,
};

+static const struct iio_event_spec kmx61_event = {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_EITHER,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+ BIT(IIO_EV_INFO_ENABLE) |
+ BIT(IIO_EV_INFO_PERIOD),
+};
+
#define KMX61_ACC_CHAN(_axis) { \
.type = IIO_ACCEL, \
.modified = 1, \
@@ -195,6 +249,8 @@ static const struct attribute_group kmx61_mag_attribute_group = {
.shift = 4, \
.endianness = IIO_LE, \
}, \
+ .event_spec = &kmx61_event, \
+ .num_event_specs = 1 \
}

#define KMX61_MAG_CHAN(_axis) { \
@@ -250,6 +306,31 @@ static int kmx61_convert_freq_to_bit(int val, int val2)
return -EINVAL;
}

+static int kmx61_convert_bit_to_freq(u8 odr_bits, int *val, int *val2)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(kmx61_samp_freq_table); i++)
+ if (odr_bits == kmx61_samp_freq_table[i].odr_bits) {
+ *val = kmx61_samp_freq_table[i].val;
+ *val2 = kmx61_samp_freq_table[i].val2;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+
+static int kmx61_convert_wake_up_odr_to_bit(int val, int val2)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(kmx61_wake_up_odr_table); ++i)
+ if (kmx61_wake_up_odr_table[i].val == val &&
+ kmx61_wake_up_odr_table[i].val2 == val2)
+ return kmx61_wake_up_odr_table[i].odr_bits;
+ return -EINVAL;
+}
+
/**
* kmx61_set_mode() - set KMX61 device operating mode
* @data - kmx61 device private data pointer
@@ -338,6 +419,21 @@ static int kmx61_get_mode(struct kmx61_data *data, u8 *mode, u8 device)
return 0;
}

+int kmx61_set_wake_up_odr(struct kmx61_data *data, int val, int val2)
+{
+ int ret, odr_bits;
+
+ odr_bits = kmx61_convert_wake_up_odr_to_bit(val, val2);
+ if (odr_bits < 0)
+ return odr_bits;
+
+ ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_CTRL2,
+ odr_bits);
+ if (ret < 0)
+ dev_err(&data->client->dev, "Error writing reg_ctrl2\n");
+ return ret;
+}
+
static int kmx61_set_odr(struct kmx61_data *data, int val, int val2, u8 device)
{
int ret;
@@ -369,6 +465,12 @@ static int kmx61_set_odr(struct kmx61_data *data, int val, int val2, u8 device)
if (ret < 0)
return ret;

+ if (device & KMX61_ACC) {
+ ret = kmx61_set_wake_up_odr(data, val, val2);
+ if (ret)
+ return ret;
+ }
+
return kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG, true);
}

@@ -449,7 +551,7 @@ static int kmx61_set_scale(struct kmx61_data *data, u16 uscale)

static int kmx61_chip_init(struct kmx61_data *data)
{
- int ret;
+ int ret, val, val2;

ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_WHO_AM_I);
if (ret < 0) {
@@ -476,11 +578,23 @@ static int kmx61_chip_init(struct kmx61_data *data)
}
data->odr_bits = ret;

+ /* set output data rate for wake up (motion detection) function */
+ ret = kmx61_convert_bit_to_freq(data->odr_bits, &val, &val2);
+ if (ret < 0)
+ return ret;
+
+ ret = kmx61_set_wake_up_odr(data, val, val2);
+ if (ret < 0)
+ return ret;
+
/* set acc/magn to OPERATION mode */
ret = kmx61_set_mode(data, 0, KMX61_ACC | KMX61_MAG, true);
if (ret < 0)
return ret;

+ data->wake_thresh = KMX61_DEFAULT_WAKE_THRESH;
+ data->wake_duration = KMX61_DEFAULT_WAKE_DURATION;
+
return 0;
}

@@ -547,6 +661,87 @@ static int kmx61_setup_new_data_interrupt(struct kmx61_data *data,
return 0;
}

+static int kmx61_chip_update_thresholds(struct kmx61_data *data)
+{
+ int ret;
+
+ ret = i2c_smbus_write_byte_data(data->client,
+ KMX61_REG_WUF_TIMER,
+ data->wake_duration);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Errow writing reg_wuf_timer\n");
+ return ret;
+ }
+
+ ret = i2c_smbus_write_byte_data(data->client,
+ KMX61_REG_WUF_THRESH,
+ data->wake_thresh);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error writing reg_wuf_thresh\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int kmx61_setup_any_motion_interrupt(struct kmx61_data *data,
+ bool status, u8 device)
+{
+ u8 mode;
+ int ret;
+
+ ret = kmx61_get_mode(data, &mode, KMX61_ACC | KMX61_MAG);
+ if (ret < 0)
+ return ret;
+
+ ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
+ if (ret < 0)
+ return ret;
+
+ ret = kmx61_chip_update_thresholds(data);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_INC1);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading reg_inc1\n");
+ return ret;
+ }
+ if (status)
+ ret |= (KMX61_REG_INC1_BIT_IEN | KMX61_REG_INC1_BIT_WUFS);
+ else
+ ret &= ~(KMX61_REG_INC1_BIT_IEN | KMX61_REG_INC1_BIT_WUFS);
+
+ ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_INC1, ret);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error writing reg_inc1\n");
+ return ret;
+ }
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_CTRL1);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
+ return ret;
+ }
+
+ if (status)
+ ret |= KMX61_REG_CTRL1_BIT_WUFE | KMX61_REG_CTRL1_BIT_BTSE;
+ else
+ ret &= ~(KMX61_REG_CTRL1_BIT_WUFE | KMX61_REG_CTRL1_BIT_BTSE);
+
+ ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_CTRL1, ret);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error writing reg_ctrl1\n");
+ return ret;
+ }
+ mode |= KMX61_ACT_STBY_BIT;
+ ret = kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG, true);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
/**
* kmx61_set_power_state() - set power state for kmx61 @device
* @data - kmx61 device private pointer
@@ -707,12 +902,111 @@ static int kmx61_write_raw(struct iio_dev *indio_dev,
}
}

+static int kmx61_read_event(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ enum iio_event_info info,
+ int *val, int *val2)
+{
+ struct kmx61_data *data = kmx61_get_data(indio_dev);
+
+ *val2 = 0;
+ switch (info) {
+ case IIO_EV_INFO_VALUE:
+ *val = data->wake_thresh;
+ break;
+ case IIO_EV_INFO_PERIOD:
+ *val = data->wake_duration;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return IIO_VAL_INT;
+}
+
+static int kmx61_write_event(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ enum iio_event_info info,
+ int val, int val2)
+{
+ struct kmx61_data *data = kmx61_get_data(indio_dev);
+
+ if (data->ev_enable_state)
+ return -EBUSY;
+
+ switch (info) {
+ case IIO_EV_INFO_VALUE:
+ data->wake_thresh = val;
+ break;
+ case IIO_EV_INFO_PERIOD:
+ data->wake_duration = val;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return IIO_VAL_INT;
+}
+
+static int kmx61_read_event_config(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir)
+{
+ struct kmx61_data *data = kmx61_get_data(indio_dev);
+
+ return data->ev_enable_state;
+}
+
+static int kmx61_write_event_config(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ int state)
+{
+ struct kmx61_data *data = kmx61_get_data(indio_dev);
+ int ret;
+
+ if (state && data->ev_enable_state)
+ return 0;
+
+ mutex_lock(&data->lock);
+
+ if (!state && data->motion_trig_on) {
+ data->ev_enable_state = 0;
+ mutex_unlock(&data->lock);
+ return 0;
+ }
+
+ ret = kmx61_set_power_state(data, state, KMX61_ACC);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ ret = kmx61_setup_any_motion_interrupt(data, state, KMX61_ACC);
+ if (ret < 0) {
+ kmx61_set_power_state(data, false, KMX61_ACC);
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ data->ev_enable_state = state;
+ mutex_unlock(&data->lock);
+
+ return 0;
+}
+
static int kmx61_acc_validate_trigger(struct iio_dev *indio_dev,
struct iio_trigger *trig)
{
struct kmx61_data *data = kmx61_get_data(indio_dev);

- if (data->acc_dready_trig != trig)
+ if (data->acc_dready_trig != trig && data->motion_trig != trig)
return -EINVAL;

return 0;
@@ -734,6 +1028,10 @@ static const struct iio_info kmx61_acc_info = {
.read_raw = kmx61_read_raw,
.write_raw = kmx61_write_raw,
.attrs = &kmx61_acc_attribute_group,
+ .read_event_value = kmx61_read_event,
+ .write_event_value = kmx61_write_event,
+ .read_event_config = kmx61_read_event_config,
+ .write_event_config = kmx61_write_event_config,
.validate_trigger = kmx61_acc_validate_trigger,
};

@@ -753,11 +1051,18 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
u8 device;

struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
- struct kmx61_data *data = iio_priv(indio_dev);
+ struct kmx61_data *data = kmx61_get_data(indio_dev);

mutex_lock(&data->lock);

- if (data->acc_dready_trig == trig)
+ if (!state && data->ev_enable_state && data->motion_trig_on) {
+ data->motion_trig_on = false;
+ mutex_unlock(&data->lock);
+ return 0;
+ }
+
+
+ if (data->acc_dready_trig == trig || data->motion_trig)
device = KMX61_ACC;
else
device = KMX61_MAG;
@@ -768,7 +1073,10 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
return ret;
}

- ret = kmx61_setup_new_data_interrupt(data, state, device);
+ if (data->acc_dready_trig == trig || data->mag_dready_trig == trig)
+ ret = kmx61_setup_new_data_interrupt(data, state, device);
+ else
+ ret = kmx61_setup_any_motion_interrupt(data, state, KMX61_ACC);
if (ret < 0) {
kmx61_set_power_state(data, false, device);
mutex_unlock(&data->lock);
@@ -777,8 +1085,10 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,

if (data->acc_dready_trig == trig)
data->acc_dready_trig_on = state;
- else
+ else if (data->mag_dready_trig == trig)
data->mag_dready_trig_on = state;
+ else
+ data->motion_trig_on = state;

mutex_unlock(&data->lock);

@@ -806,6 +1116,99 @@ static const struct iio_trigger_ops kmx61_trigger_ops = {
.owner = THIS_MODULE,
};

+static irqreturn_t kmx61_event_handler(int irq, void *private)
+{
+ struct kmx61_data *data = private;
+ struct iio_dev *indio_dev = data->acc_indio_dev;
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_INS1);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading reg_ins1\n");
+ goto ack_intr;
+ }
+
+ if (ret & KMX61_REG_INS1_BIT_WUFS) {
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_INS2);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading reg_ins2\n");
+ goto ack_intr;
+ }
+
+ if (ret & KMX61_REG_INS2_BIT_XN)
+ iio_push_event(indio_dev,
+ IIO_MOD_EVENT_CODE(IIO_ACCEL,
+ 0,
+ IIO_MOD_X,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_FALLING),
+ 0);
+
+ if (ret & KMX61_REG_INS2_BIT_XP)
+ iio_push_event(indio_dev,
+ IIO_MOD_EVENT_CODE(IIO_ACCEL,
+ 0,
+ IIO_MOD_X,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_RISING),
+ 0);
+
+ if (ret & KMX61_REG_INS2_BIT_YN)
+ iio_push_event(indio_dev,
+ IIO_MOD_EVENT_CODE(IIO_ACCEL,
+ 0,
+ IIO_MOD_Y,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_FALLING),
+ 0);
+
+ if (ret & KMX61_REG_INS2_BIT_YP)
+ iio_push_event(indio_dev,
+ IIO_MOD_EVENT_CODE(IIO_ACCEL,
+ 0,
+ IIO_MOD_Y,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_RISING),
+ 0);
+
+ if (ret & KMX61_REG_INS2_BIT_ZN)
+ iio_push_event(indio_dev,
+ IIO_MOD_EVENT_CODE(IIO_ACCEL,
+ 0,
+ IIO_MOD_Z,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_FALLING),
+ 0);
+
+ if (ret & KMX61_REG_INS2_BIT_ZP)
+ iio_push_event(indio_dev,
+ IIO_MOD_EVENT_CODE(IIO_ACCEL,
+ 0,
+ IIO_MOD_Z,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_RISING),
+ 0);
+ }
+
+ack_intr:
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_CTRL1);
+ if (ret < 0)
+ dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
+
+ ret |= KMX61_REG_CTRL1_BIT_RES;
+ ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_CTRL1, ret);
+ if (ret < 0)
+ dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_INL);
+ if (ret < 0)
+ dev_err(&data->client->dev, "Error reading reg_inl\n");
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_INS1);
+
+ return IRQ_HANDLED;
+}
+
static irqreturn_t kmx61_data_rdy_trig_poll(int irq, void *private)
{
struct kmx61_data *data = private;
@@ -815,6 +1218,11 @@ static irqreturn_t kmx61_data_rdy_trig_poll(int irq, void *private)
if (data->mag_dready_trig_on)
iio_trigger_poll(data->mag_dready_trig);

+ if (data->motion_trig_on)
+ iio_trigger_poll(data->motion_trig);
+
+ if (data->ev_enable_state)
+ return IRQ_WAKE_THREAD;
return IRQ_HANDLED;
}

@@ -982,7 +1390,7 @@ static int kmx61_probe(struct i2c_client *client,
if (client->irq >= 0) {
ret = devm_request_threaded_irq(&client->dev, client->irq,
kmx61_data_rdy_trig_poll,
- NULL,
+ kmx61_event_handler,
IRQF_TRIGGER_RISING,
KMX61_IRQ_NAME,
data);
@@ -1003,6 +1411,14 @@ static int kmx61_probe(struct i2c_client *client,
goto err_trigger_unregister;
}

+ data->motion_trig =
+ kmx61_trigger_setup(data, data->acc_indio_dev,
+ "any-motion");
+ if (IS_ERR(data->motion_trig)) {
+ ret = PTR_ERR(data->motion_trig);
+ goto err_trigger_unregister;
+ }
+
ret = iio_triggered_buffer_setup(data->acc_indio_dev,
&iio_pollfunc_store_time,
kmx61_trigger_handler,
@@ -1060,6 +1476,8 @@ err_trigger_unregister:
iio_trigger_unregister(data->acc_dready_trig);
if (data->mag_dready_trig)
iio_trigger_unregister(data->mag_dready_trig);
+ if (data->motion_trig)
+ iio_trigger_unregister(data->motion_trig);
err_chip_uninit:
kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
return ret;
@@ -1081,6 +1499,7 @@ static int kmx61_remove(struct i2c_client *client)
iio_triggered_buffer_cleanup(data->mag_indio_dev);
iio_trigger_unregister(data->acc_dready_trig);
iio_trigger_unregister(data->mag_dready_trig);
+ iio_trigger_unregister(data->motion_trig);
}

mutex_lock(&data->lock);
--
1.9.1

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