diff options
Diffstat (limited to 'drivers/iio/gyro/itg3200_buffer.c')
| -rw-r--r-- | drivers/iio/gyro/itg3200_buffer.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/iio/gyro/itg3200_buffer.c b/drivers/iio/gyro/itg3200_buffer.c new file mode 100644 index 000000000..56aac0a9b --- /dev/null +++ b/drivers/iio/gyro/itg3200_buffer.c @@ -0,0 +1,159 @@ +/* + * 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); + /* + * Ensure correct alignment and padding including for the + * timestamp that may be inserted. + */ + struct { + __be16 buf[ITG3200_SCAN_ELEMENTS]; + s64 ts __aligned(8); + } scan; + + int ret = itg3200_read_all_channels(st->i2c, scan.buf); + if (ret < 0) + goto error_ret; + + iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp); + +error_ret: + iio_trigger_notify_done(indio_dev->trig); + + 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 = iio_trigger_get_drvdata(trig); + 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 = { + .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; + iio_trigger_set_drvdata(st->trig, indio_dev); + ret = iio_trigger_register(st->trig); + if (ret) + goto error_free_irq; + + /* select default trigger */ + indio_dev->trig = iio_trigger_get(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); +} |