[mirror_ubuntu-hirsute-kernel.git] / drivers / i2c / muxes / i2c-mux-gpmux.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");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
ac8498f0 PR	2	/*
	3	* General Purpose I2C multiplexer
	4	*
	5	* Copyright (C) 2017 Axentia Technologies AB
	6	*
	7	* Author: Peter Rosin <peda@axentia.se>
ac8498f0 PR	8	*/
	9
	10	#include <linux/i2c.h>
	11	#include <linux/i2c-mux.h>
	12	#include <linux/module.h>
	13	#include <linux/mux/consumer.h>
	14	#include <linux/of_device.h>
	15	#include <linux/platform_device.h>
	16
	17	struct mux {
	18	struct mux_control *control;
	19
	20	bool do_not_deselect;
	21	};
	22
	23	static int i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
	24	{
	25	struct mux *mux = i2c_mux_priv(muxc);
	26	int ret;
	27
	28	ret = mux_control_select(mux->control, chan);
	29	mux->do_not_deselect = ret < 0;
	30
	31	return ret;
	32	}
	33
	34	static int i2c_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
	35	{
	36	struct mux *mux = i2c_mux_priv(muxc);
	37
	38	if (mux->do_not_deselect)
	39	return 0;
	40
	41	return mux_control_deselect(mux->control);
	42	}
	43
	44	static struct i2c_adapter mux_parent_adapter(struct device dev)
	45	{
	46	struct device_node *np = dev->of_node;
	47	struct device_node *parent_np;
	48	struct i2c_adapter *parent;
	49
	50	parent_np = of_parse_phandle(np, "i2c-parent", 0);
	51	if (!parent_np) {
	52	dev_err(dev, "Cannot parse i2c-parent\n");
	53	return ERR_PTR(-ENODEV);
	54	}
	55	parent = of_find_i2c_adapter_by_node(parent_np);
	56	of_node_put(parent_np);
	57	if (!parent)
	58	return ERR_PTR(-EPROBE_DEFER);
	59
	60	return parent;
	61	}
	62
	63	static const struct of_device_id i2c_mux_of_match[] = {
	64	{ .compatible = "i2c-mux", },
	65	{},
	66	};
	67	MODULE_DEVICE_TABLE(of, i2c_mux_of_match);
	68
	69	static int i2c_mux_probe(struct platform_device *pdev)
	70	{
	71	struct device *dev = &pdev->dev;
72	struct device_node *np = dev->of_node;
73	struct device_node *child;
74	struct i2c_mux_core *muxc;
75	struct mux *mux;
76	struct i2c_adapter *parent;
77	int children;
78	int ret;
79
80	if (!np)
81	return -ENODEV;
82
83	mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
84	if (!mux)
85	return -ENOMEM;
86
87	mux->control = devm_mux_control_get(dev, NULL);
432d159a KK	88	if (IS_ERR(mux->control))
	89	return dev_err_probe(dev, PTR_ERR(mux->control),
	90	"failed to get control-mux\n");
ac8498f0 PR	91
ac8498f0 PR	92	parent = mux_parent_adapter(dev);
432d159a KK	93	if (IS_ERR(parent))
	94	return dev_err_probe(dev, PTR_ERR(parent),
	95	"failed to get i2c-parent adapter\n");
ac8498f0 PR	96
	97	children = of_get_child_count(np);
	98
	99	muxc = i2c_mux_alloc(parent, dev, children, 0, 0,
	100	i2c_mux_select, i2c_mux_deselect);
	101	if (!muxc) {
	102	ret = -ENOMEM;
	103	goto err_parent;
	104	}
	105	muxc->priv = mux;
	106
	107	platform_set_drvdata(pdev, muxc);
	108
	109	muxc->mux_locked = of_property_read_bool(np, "mux-locked");
	110
	111	for_each_child_of_node(np, child) {
	112	u32 chan;
	113
	114	ret = of_property_read_u32(child, "reg", &chan);
	115	if (ret < 0) {
49d54abe RH	116	dev_err(dev, "no reg property for node '%pOFn'\n",
49d54abe RH	117	child);
ac8498f0 PR	118	goto err_children;
	119	}
	120
	121	if (chan >= mux_control_states(mux->control)) {
	122	dev_err(dev, "invalid reg %u\n", chan);
	123	ret = -EINVAL;
	124	goto err_children;
	125	}
	126
	127	ret = i2c_mux_add_adapter(muxc, 0, chan, 0);
	128	if (ret)
	129	goto err_children;
	130	}
	131
	132	dev_info(dev, "%d-port mux on %s adapter\n", children, parent->name);
	133
	134	return 0;
	135
	136	err_children:
	137	i2c_mux_del_adapters(muxc);
	138	err_parent:
	139	i2c_put_adapter(parent);
	140
	141	return ret;
	142	}
	143
	144	static int i2c_mux_remove(struct platform_device *pdev)
	145	{
	146	struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
	147
	148	i2c_mux_del_adapters(muxc);
	149	i2c_put_adapter(muxc->parent);
	150
	151	return 0;
	152	}
	153
	154	static struct platform_driver i2c_mux_driver = {
	155	.probe = i2c_mux_probe,
	156	.remove = i2c_mux_remove,
	157	.driver = {
	158	.name = "i2c-mux-gpmux",
	159	.of_match_table = i2c_mux_of_match,
	160	},
	161	};
	162	module_platform_driver(i2c_mux_driver);
	163
	164	MODULE_DESCRIPTION("General Purpose I2C multiplexer driver");
	165	MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
	166	MODULE_LICENSE("GPL v2");