167 lines
3.5 KiB
C
167 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* General Purpose I2C multiplexer
|
|
*
|
|
* Copyright (C) 2017 Axentia Technologies AB
|
|
*
|
|
* Author: Peter Rosin <peda@axentia.se>
|
|
*/
|
|
|
|
#include <linux/i2c.h>
|
|
#include <linux/i2c-mux.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mux/consumer.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
struct mux {
|
|
struct mux_control *control;
|
|
|
|
bool do_not_deselect;
|
|
};
|
|
|
|
static int i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
|
|
{
|
|
struct mux *mux = i2c_mux_priv(muxc);
|
|
int ret;
|
|
|
|
ret = mux_control_select(mux->control, chan);
|
|
mux->do_not_deselect = ret < 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int i2c_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
|
|
{
|
|
struct mux *mux = i2c_mux_priv(muxc);
|
|
|
|
if (mux->do_not_deselect)
|
|
return 0;
|
|
|
|
return mux_control_deselect(mux->control);
|
|
}
|
|
|
|
static struct i2c_adapter *mux_parent_adapter(struct device *dev)
|
|
{
|
|
struct device_node *np = dev->of_node;
|
|
struct device_node *parent_np;
|
|
struct i2c_adapter *parent;
|
|
|
|
parent_np = of_parse_phandle(np, "i2c-parent", 0);
|
|
if (!parent_np) {
|
|
dev_err(dev, "Cannot parse i2c-parent\n");
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
parent = of_find_i2c_adapter_by_node(parent_np);
|
|
of_node_put(parent_np);
|
|
if (!parent)
|
|
return ERR_PTR(-EPROBE_DEFER);
|
|
|
|
return parent;
|
|
}
|
|
|
|
static const struct of_device_id i2c_mux_of_match[] = {
|
|
{ .compatible = "i2c-mux", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, i2c_mux_of_match);
|
|
|
|
static int i2c_mux_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct device_node *np = dev->of_node;
|
|
struct device_node *child;
|
|
struct i2c_mux_core *muxc;
|
|
struct mux *mux;
|
|
struct i2c_adapter *parent;
|
|
int children;
|
|
int ret;
|
|
|
|
if (!np)
|
|
return -ENODEV;
|
|
|
|
mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
|
|
if (!mux)
|
|
return -ENOMEM;
|
|
|
|
mux->control = devm_mux_control_get(dev, NULL);
|
|
if (IS_ERR(mux->control))
|
|
return dev_err_probe(dev, PTR_ERR(mux->control),
|
|
"failed to get control-mux\n");
|
|
|
|
parent = mux_parent_adapter(dev);
|
|
if (IS_ERR(parent))
|
|
return dev_err_probe(dev, PTR_ERR(parent),
|
|
"failed to get i2c-parent adapter\n");
|
|
|
|
children = of_get_child_count(np);
|
|
|
|
muxc = i2c_mux_alloc(parent, dev, children, 0, 0,
|
|
i2c_mux_select, i2c_mux_deselect);
|
|
if (!muxc) {
|
|
ret = -ENOMEM;
|
|
goto err_parent;
|
|
}
|
|
muxc->priv = mux;
|
|
|
|
platform_set_drvdata(pdev, muxc);
|
|
|
|
muxc->mux_locked = of_property_read_bool(np, "mux-locked");
|
|
|
|
for_each_child_of_node(np, child) {
|
|
u32 chan;
|
|
|
|
ret = of_property_read_u32(child, "reg", &chan);
|
|
if (ret < 0) {
|
|
dev_err(dev, "no reg property for node '%pOFn'\n",
|
|
child);
|
|
goto err_children;
|
|
}
|
|
|
|
if (chan >= mux_control_states(mux->control)) {
|
|
dev_err(dev, "invalid reg %u\n", chan);
|
|
ret = -EINVAL;
|
|
goto err_children;
|
|
}
|
|
|
|
ret = i2c_mux_add_adapter(muxc, 0, chan, 0);
|
|
if (ret)
|
|
goto err_children;
|
|
}
|
|
|
|
dev_info(dev, "%d-port mux on %s adapter\n", children, parent->name);
|
|
|
|
return 0;
|
|
|
|
err_children:
|
|
i2c_mux_del_adapters(muxc);
|
|
err_parent:
|
|
i2c_put_adapter(parent);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int i2c_mux_remove(struct platform_device *pdev)
|
|
{
|
|
struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
|
|
|
|
i2c_mux_del_adapters(muxc);
|
|
i2c_put_adapter(muxc->parent);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver i2c_mux_driver = {
|
|
.probe = i2c_mux_probe,
|
|
.remove = i2c_mux_remove,
|
|
.driver = {
|
|
.name = "i2c-mux-gpmux",
|
|
.of_match_table = i2c_mux_of_match,
|
|
},
|
|
};
|
|
module_platform_driver(i2c_mux_driver);
|
|
|
|
MODULE_DESCRIPTION("General Purpose I2C multiplexer driver");
|
|
MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
|
|
MODULE_LICENSE("GPL v2");
|