1 files changed, 167 insertions, 0 deletions

diff --git a/drivers/i2c/muxes/i2c-mux-gpmux.c b/drivers/i2c/muxes/i2c-mux-gpmux.c
new file mode 100644
index 000000000..0ebc12575
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-gpmux.c
@@ -0,0 +1,167 @@
+// 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_get_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:
+	of_node_put(child);
+	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");