// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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>
 */

#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];
                aligned_s64 ts;
        } 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(&st->i2c->dev, "%s-dev%d", indio_dev->name,
                                     iio_device_id(indio_dev));
        if (!st->trig)
                return -ENOMEM;

        ret = request_irq(st->i2c->irq, &iio_trigger_generic_data_rdy_poll,
                          IRQF_TRIGGER_RISING | IRQF_NO_THREAD,
                          "itg3200_data_rdy", st->trig);
        if (ret)
                goto error_free_trig;


        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);
}