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![Krzysztof Kozlowski](/assets/img/avatar_default.png)
Common pattern of handling deferred probe can be simplified with dev_err_probe(). Less code and also it prints the error value. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Peter Rosin <peda@axentia.se> Link: https://lore.kernel.org/r/20200829064726.26268-18-krzk@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
459 lines
9.9 KiB
C
459 lines
9.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* IIO multiplexer driver
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*
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* Copyright (C) 2017 Axentia Technologies AB
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*
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* Author: Peter Rosin <peda@axentia.se>
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*/
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#include <linux/err.h>
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#include <linux/iio/consumer.h>
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#include <linux/iio/iio.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/mux/consumer.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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struct mux_ext_info_cache {
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char *data;
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ssize_t size;
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};
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struct mux_child {
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struct mux_ext_info_cache *ext_info_cache;
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};
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struct mux {
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int cached_state;
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struct mux_control *control;
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struct iio_channel *parent;
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struct iio_dev *indio_dev;
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struct iio_chan_spec *chan;
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struct iio_chan_spec_ext_info *ext_info;
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struct mux_child *child;
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};
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static int iio_mux_select(struct mux *mux, int idx)
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{
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struct mux_child *child = &mux->child[idx];
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struct iio_chan_spec const *chan = &mux->chan[idx];
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int ret;
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int i;
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ret = mux_control_select(mux->control, chan->channel);
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if (ret < 0) {
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mux->cached_state = -1;
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return ret;
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}
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if (mux->cached_state == chan->channel)
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return 0;
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if (chan->ext_info) {
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for (i = 0; chan->ext_info[i].name; ++i) {
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const char *attr = chan->ext_info[i].name;
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struct mux_ext_info_cache *cache;
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cache = &child->ext_info_cache[i];
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if (cache->size < 0)
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continue;
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ret = iio_write_channel_ext_info(mux->parent, attr,
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cache->data,
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cache->size);
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if (ret < 0) {
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mux_control_deselect(mux->control);
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mux->cached_state = -1;
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return ret;
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}
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}
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}
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mux->cached_state = chan->channel;
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return 0;
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}
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static void iio_mux_deselect(struct mux *mux)
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{
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mux_control_deselect(mux->control);
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}
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static int mux_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct mux *mux = iio_priv(indio_dev);
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int idx = chan - mux->chan;
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int ret;
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ret = iio_mux_select(mux, idx);
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if (ret < 0)
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return ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = iio_read_channel_raw(mux->parent, val);
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break;
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case IIO_CHAN_INFO_SCALE:
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ret = iio_read_channel_scale(mux->parent, val, val2);
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break;
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default:
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ret = -EINVAL;
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}
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iio_mux_deselect(mux);
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return ret;
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}
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static int mux_read_avail(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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const int **vals, int *type, int *length,
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long mask)
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{
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struct mux *mux = iio_priv(indio_dev);
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int idx = chan - mux->chan;
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int ret;
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ret = iio_mux_select(mux, idx);
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if (ret < 0)
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return ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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*type = IIO_VAL_INT;
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ret = iio_read_avail_channel_raw(mux->parent, vals, length);
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break;
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default:
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ret = -EINVAL;
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}
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iio_mux_deselect(mux);
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return ret;
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}
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static int mux_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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struct mux *mux = iio_priv(indio_dev);
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int idx = chan - mux->chan;
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int ret;
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ret = iio_mux_select(mux, idx);
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if (ret < 0)
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return ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = iio_write_channel_raw(mux->parent, val);
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break;
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default:
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ret = -EINVAL;
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}
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iio_mux_deselect(mux);
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return ret;
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}
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static const struct iio_info mux_info = {
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.read_raw = mux_read_raw,
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.read_avail = mux_read_avail,
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.write_raw = mux_write_raw,
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};
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static ssize_t mux_read_ext_info(struct iio_dev *indio_dev, uintptr_t private,
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struct iio_chan_spec const *chan, char *buf)
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{
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struct mux *mux = iio_priv(indio_dev);
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int idx = chan - mux->chan;
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ssize_t ret;
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ret = iio_mux_select(mux, idx);
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if (ret < 0)
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return ret;
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ret = iio_read_channel_ext_info(mux->parent,
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mux->ext_info[private].name,
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buf);
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iio_mux_deselect(mux);
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return ret;
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}
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static ssize_t mux_write_ext_info(struct iio_dev *indio_dev, uintptr_t private,
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struct iio_chan_spec const *chan,
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const char *buf, size_t len)
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{
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struct device *dev = indio_dev->dev.parent;
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struct mux *mux = iio_priv(indio_dev);
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int idx = chan - mux->chan;
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char *new;
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ssize_t ret;
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if (len >= PAGE_SIZE)
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return -EINVAL;
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ret = iio_mux_select(mux, idx);
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if (ret < 0)
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return ret;
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new = devm_kmemdup(dev, buf, len + 1, GFP_KERNEL);
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if (!new) {
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iio_mux_deselect(mux);
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return -ENOMEM;
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}
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new[len] = 0;
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ret = iio_write_channel_ext_info(mux->parent,
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mux->ext_info[private].name,
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buf, len);
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if (ret < 0) {
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iio_mux_deselect(mux);
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devm_kfree(dev, new);
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return ret;
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}
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devm_kfree(dev, mux->child[idx].ext_info_cache[private].data);
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mux->child[idx].ext_info_cache[private].data = new;
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mux->child[idx].ext_info_cache[private].size = len;
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iio_mux_deselect(mux);
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return ret;
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}
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static int mux_configure_channel(struct device *dev, struct mux *mux,
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u32 state, const char *label, int idx)
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{
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struct mux_child *child = &mux->child[idx];
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struct iio_chan_spec *chan = &mux->chan[idx];
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struct iio_chan_spec const *pchan = mux->parent->channel;
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char *page = NULL;
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int num_ext_info;
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int i;
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int ret;
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chan->indexed = 1;
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chan->output = pchan->output;
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chan->datasheet_name = label;
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chan->ext_info = mux->ext_info;
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ret = iio_get_channel_type(mux->parent, &chan->type);
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if (ret < 0) {
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dev_err(dev, "failed to get parent channel type\n");
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return ret;
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}
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if (iio_channel_has_info(pchan, IIO_CHAN_INFO_RAW))
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chan->info_mask_separate |= BIT(IIO_CHAN_INFO_RAW);
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if (iio_channel_has_info(pchan, IIO_CHAN_INFO_SCALE))
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chan->info_mask_separate |= BIT(IIO_CHAN_INFO_SCALE);
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if (iio_channel_has_available(pchan, IIO_CHAN_INFO_RAW))
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chan->info_mask_separate_available |= BIT(IIO_CHAN_INFO_RAW);
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if (state >= mux_control_states(mux->control)) {
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dev_err(dev, "too many channels\n");
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return -EINVAL;
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}
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chan->channel = state;
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num_ext_info = iio_get_channel_ext_info_count(mux->parent);
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if (num_ext_info) {
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page = devm_kzalloc(dev, PAGE_SIZE, GFP_KERNEL);
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if (!page)
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return -ENOMEM;
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}
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child->ext_info_cache = devm_kcalloc(dev,
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num_ext_info,
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sizeof(*child->ext_info_cache),
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GFP_KERNEL);
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if (!child->ext_info_cache)
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return -ENOMEM;
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for (i = 0; i < num_ext_info; ++i) {
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child->ext_info_cache[i].size = -1;
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if (!pchan->ext_info[i].write)
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continue;
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if (!pchan->ext_info[i].read)
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continue;
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ret = iio_read_channel_ext_info(mux->parent,
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mux->ext_info[i].name,
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page);
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if (ret < 0) {
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dev_err(dev, "failed to get ext_info '%s'\n",
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pchan->ext_info[i].name);
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return ret;
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}
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if (ret >= PAGE_SIZE) {
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dev_err(dev, "too large ext_info '%s'\n",
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pchan->ext_info[i].name);
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return -EINVAL;
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}
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child->ext_info_cache[i].data = devm_kmemdup(dev, page, ret + 1,
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GFP_KERNEL);
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if (!child->ext_info_cache[i].data)
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return -ENOMEM;
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child->ext_info_cache[i].data[ret] = 0;
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child->ext_info_cache[i].size = ret;
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}
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if (page)
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devm_kfree(dev, page);
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return 0;
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}
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/*
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* Same as of_property_for_each_string(), but also keeps track of the
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* index of each string.
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*/
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#define of_property_for_each_string_index(np, propname, prop, s, i) \
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for (prop = of_find_property(np, propname, NULL), \
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s = of_prop_next_string(prop, NULL), \
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i = 0; \
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s; \
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s = of_prop_next_string(prop, s), \
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i++)
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static int mux_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *np = pdev->dev.of_node;
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struct iio_dev *indio_dev;
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struct iio_channel *parent;
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struct mux *mux;
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struct property *prop;
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const char *label;
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u32 state;
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int sizeof_ext_info;
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int children;
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int sizeof_priv;
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int i;
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int ret;
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if (!np)
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return -ENODEV;
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parent = devm_iio_channel_get(dev, "parent");
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if (IS_ERR(parent))
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return dev_err_probe(dev, PTR_ERR(parent),
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"failed to get parent channel\n");
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sizeof_ext_info = iio_get_channel_ext_info_count(parent);
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if (sizeof_ext_info) {
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sizeof_ext_info += 1; /* one extra entry for the sentinel */
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sizeof_ext_info *= sizeof(*mux->ext_info);
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}
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children = 0;
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of_property_for_each_string(np, "channels", prop, label) {
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if (*label)
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children++;
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}
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if (children <= 0) {
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dev_err(dev, "not even a single child\n");
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return -EINVAL;
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}
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sizeof_priv = sizeof(*mux);
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sizeof_priv += sizeof(*mux->child) * children;
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sizeof_priv += sizeof(*mux->chan) * children;
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sizeof_priv += sizeof_ext_info;
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indio_dev = devm_iio_device_alloc(dev, sizeof_priv);
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if (!indio_dev)
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return -ENOMEM;
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mux = iio_priv(indio_dev);
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mux->child = (struct mux_child *)(mux + 1);
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mux->chan = (struct iio_chan_spec *)(mux->child + children);
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platform_set_drvdata(pdev, indio_dev);
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mux->parent = parent;
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mux->cached_state = -1;
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indio_dev->name = dev_name(dev);
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indio_dev->info = &mux_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = mux->chan;
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indio_dev->num_channels = children;
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if (sizeof_ext_info) {
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mux->ext_info = devm_kmemdup(dev,
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parent->channel->ext_info,
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sizeof_ext_info, GFP_KERNEL);
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if (!mux->ext_info)
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return -ENOMEM;
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for (i = 0; mux->ext_info[i].name; ++i) {
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if (parent->channel->ext_info[i].read)
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mux->ext_info[i].read = mux_read_ext_info;
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if (parent->channel->ext_info[i].write)
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mux->ext_info[i].write = mux_write_ext_info;
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mux->ext_info[i].private = i;
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}
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}
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mux->control = devm_mux_control_get(dev, NULL);
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if (IS_ERR(mux->control)) {
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if (PTR_ERR(mux->control) != -EPROBE_DEFER)
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dev_err(dev, "failed to get control-mux\n");
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return PTR_ERR(mux->control);
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}
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i = 0;
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of_property_for_each_string_index(np, "channels", prop, label, state) {
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if (!*label)
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continue;
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ret = mux_configure_channel(dev, mux, state, label, i++);
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if (ret < 0)
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return ret;
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}
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ret = devm_iio_device_register(dev, indio_dev);
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if (ret) {
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dev_err(dev, "failed to register iio device\n");
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return ret;
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}
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return 0;
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}
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static const struct of_device_id mux_match[] = {
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{ .compatible = "io-channel-mux" },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, mux_match);
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static struct platform_driver mux_driver = {
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.probe = mux_probe,
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.driver = {
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.name = "iio-mux",
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.of_match_table = mux_match,
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},
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};
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module_platform_driver(mux_driver);
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MODULE_DESCRIPTION("IIO multiplexer driver");
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MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
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MODULE_LICENSE("GPL v2");
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