diff options
Diffstat (limited to 'drivers/iio/accel/mma8452.c')
| -rw-r--r-- | drivers/iio/accel/mma8452.c | 212 |
1 files changed, 211 insertions, 1 deletions
diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c index 877ce2954196..f30eb9b7a99c 100644 --- a/drivers/iio/accel/mma8452.c +++ b/drivers/iio/accel/mma8452.c @@ -9,7 +9,7 @@ * * 7-bit I2C slave address 0x1c/0x1d (pin selectable) * - * TODO: interrupt, thresholding, orientation / freefall events, autosleep + * TODO: orientation / freefall events, autosleep */ #include <linux/module.h> @@ -19,20 +19,33 @@ #include <linux/iio/trigger_consumer.h> #include <linux/iio/buffer.h> #include <linux/iio/triggered_buffer.h> +#include <linux/iio/events.h> #include <linux/delay.h> #define MMA8452_STATUS 0x00 #define MMA8452_OUT_X 0x01 /* MSB first, 12-bit */ #define MMA8452_OUT_Y 0x03 #define MMA8452_OUT_Z 0x05 +#define MMA8452_INT_SRC 0x0c #define MMA8452_WHO_AM_I 0x0d #define MMA8452_DATA_CFG 0x0e +#define MMA8452_TRANSIENT_CFG 0x1d +#define MMA8452_TRANSIENT_CFG_ELE BIT(4) +#define MMA8452_TRANSIENT_CFG_CHAN(chan) BIT(chan + 1) +#define MMA8452_TRANSIENT_SRC 0x1e +#define MMA8452_TRANSIENT_SRC_XTRANSE BIT(1) +#define MMA8452_TRANSIENT_SRC_YTRANSE BIT(3) +#define MMA8452_TRANSIENT_SRC_ZTRANSE BIT(5) +#define MMA8452_TRANSIENT_THS 0x1f +#define MMA8452_TRANSIENT_THS_MASK 0x7f #define MMA8452_OFF_X 0x2f #define MMA8452_OFF_Y 0x30 #define MMA8452_OFF_Z 0x31 #define MMA8452_CTRL_REG1 0x2a #define MMA8452_CTRL_REG2 0x2b #define MMA8452_CTRL_REG2_RST BIT(6) +#define MMA8452_CTRL_REG4 0x2d +#define MMA8452_CTRL_REG5 0x2e #define MMA8452_MAX_REG 0x31 @@ -48,6 +61,8 @@ #define MMA8452_DATA_CFG_FS_4G 1 #define MMA8452_DATA_CFG_FS_8G 2 +#define MMA8452_INT_TRANS BIT(5) + #define MMA8452_DEVICE_ID 0x2a struct mma8452_data { @@ -274,6 +289,126 @@ static int mma8452_write_raw(struct iio_dev *indio_dev, } } +static int mma8452_read_thresh(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 mma8452_data *data = iio_priv(indio_dev); + int ret; + + ret = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_THS); + if (ret < 0) + return ret; + + *val = ret & MMA8452_TRANSIENT_THS_MASK; + + return IIO_VAL_INT; +} + +static int mma8452_write_thresh(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 mma8452_data *data = iio_priv(indio_dev); + + return mma8452_change_config(data, MMA8452_TRANSIENT_THS, + val & MMA8452_TRANSIENT_THS_MASK); +} + +static int mma8452_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 mma8452_data *data = iio_priv(indio_dev); + int ret; + + ret = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_CFG); + if (ret < 0) + return ret; + + return ret & MMA8452_TRANSIENT_CFG_CHAN(chan->scan_index) ? 1 : 0; +} + +static int mma8452_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 mma8452_data *data = iio_priv(indio_dev); + int val; + + val = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_CFG); + if (val < 0) + return val; + + if (state) + val |= MMA8452_TRANSIENT_CFG_CHAN(chan->scan_index); + else + val &= ~MMA8452_TRANSIENT_CFG_CHAN(chan->scan_index); + + val |= MMA8452_TRANSIENT_CFG_ELE; + + return mma8452_change_config(data, MMA8452_TRANSIENT_CFG, val); +} + +static void mma8452_transient_interrupt(struct iio_dev *indio_dev) +{ + struct mma8452_data *data = iio_priv(indio_dev); + s64 ts = iio_get_time_ns(); + int src; + + src = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_SRC); + if (src < 0) + return; + + if (src & MMA8452_TRANSIENT_SRC_XTRANSE) + iio_push_event(indio_dev, + IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_X, + IIO_EV_TYPE_THRESH, + IIO_EV_DIR_RISING), + ts); + + if (src & MMA8452_TRANSIENT_SRC_YTRANSE) + iio_push_event(indio_dev, + IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Y, + IIO_EV_TYPE_THRESH, + IIO_EV_DIR_RISING), + ts); + + if (src & MMA8452_TRANSIENT_SRC_ZTRANSE) + iio_push_event(indio_dev, + IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Z, + IIO_EV_TYPE_THRESH, + IIO_EV_DIR_RISING), + ts); +} + +static irqreturn_t mma8452_interrupt(int irq, void *p) +{ + struct iio_dev *indio_dev = p; + struct mma8452_data *data = iio_priv(indio_dev); + int src; + + src = i2c_smbus_read_byte_data(data->client, MMA8452_INT_SRC); + if (src < 0) + return IRQ_NONE; + + if (src & MMA8452_INT_TRANS) { + mma8452_transient_interrupt(indio_dev); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + static irqreturn_t mma8452_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; @@ -316,6 +451,31 @@ static int mma8452_reg_access_dbg(struct iio_dev *indio_dev, return 0; } +static const struct iio_event_spec mma8452_transient_event[] = { + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_RISING, + .mask_separate = BIT(IIO_EV_INFO_ENABLE), + .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) + }, +}; + +/* + * Threshold is configured in fixed 8G/127 steps regardless of + * currently selected scale for measurement. + */ +static IIO_CONST_ATTR_NAMED(accel_transient_scale, in_accel_scale, "0.617742"); + +static struct attribute *mma8452_event_attributes[] = { + &iio_const_attr_accel_transient_scale.dev_attr.attr, + NULL, +}; + +static struct attribute_group mma8452_event_attribute_group = { + .attrs = mma8452_event_attributes, + .name = "events", +}; + #define MMA8452_CHANNEL(axis, idx) { \ .type = IIO_ACCEL, \ .modified = 1, \ @@ -332,6 +492,8 @@ static int mma8452_reg_access_dbg(struct iio_dev *indio_dev, .shift = 4, \ .endianness = IIO_BE, \ }, \ + .event_spec = mma8452_transient_event, \ + .num_event_specs = ARRAY_SIZE(mma8452_transient_event), \ } static const struct iio_chan_spec mma8452_channels[] = { @@ -355,6 +517,11 @@ static const struct iio_info mma8452_info = { .attrs = &mma8452_group, .read_raw = &mma8452_read_raw, .write_raw = &mma8452_write_raw, + .event_attrs = &mma8452_event_attribute_group, + .read_event_value = &mma8452_read_thresh, + .write_event_value = &mma8452_write_thresh, + .read_event_config = &mma8452_read_event_config, + .write_event_config = &mma8452_write_event_config, .debugfs_reg_access = &mma8452_reg_access_dbg, .driver_module = THIS_MODULE, }; @@ -425,6 +592,38 @@ static int mma8452_probe(struct i2c_client *client, if (ret < 0) return ret; + /* + * By default set transient threshold to max to avoid events if + * enabling without configuring threshold. + */ + ret = i2c_smbus_write_byte_data(client, MMA8452_TRANSIENT_THS, + MMA8452_TRANSIENT_THS_MASK); + if (ret < 0) + return ret; + + if (client->irq) { + /* + * Although we enable the transient interrupt source once and + * for all here the transient event detection itself is not + * enabled until userspace asks for it by + * mma8452_write_event_config() + */ + int supported_interrupts = MMA8452_INT_TRANS; + + /* Assume wired to INT1 pin */ + ret = i2c_smbus_write_byte_data(client, + MMA8452_CTRL_REG5, + supported_interrupts); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte_data(client, + MMA8452_CTRL_REG4, + supported_interrupts); + if (ret < 0) + return ret; + } + data->ctrl_reg1 = MMA8452_CTRL_ACTIVE | (MMA8452_CTRL_DR_DEFAULT << MMA8452_CTRL_DR_SHIFT); ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG1, @@ -437,9 +636,20 @@ static int mma8452_probe(struct i2c_client *client, if (ret < 0) return ret; + if (client->irq) { + ret = devm_request_threaded_irq(&client->dev, + client->irq, + NULL, mma8452_interrupt, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + client->name, indio_dev); + if (ret) + goto buffer_cleanup; + } + ret = iio_device_register(indio_dev); if (ret < 0) goto buffer_cleanup; + return 0; buffer_cleanup: |