Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 210 insertions, 0 deletions

diff --git a/drivers/i2c/muxes/i2c-mux-pinctrl.c b/drivers/i2c/muxes/i2c-mux-pinctrl.c
new file mode 100644
index 000000000..cc6818aab
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-pinctrl.c
@@ -0,0 +1,210 @@
+/*
+ * I2C multiplexer using pinctrl API
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include "../../pinctrl/core.h"
+
+struct i2c_mux_pinctrl {
+	struct pinctrl *pinctrl;
+	struct pinctrl_state **states;
+};
+
+static int i2c_mux_pinctrl_select(struct i2c_mux_core *muxc, u32 chan)
+{
+	struct i2c_mux_pinctrl *mux = i2c_mux_priv(muxc);
+
+	return pinctrl_select_state(mux->pinctrl, mux->states[chan]);
+}
+
+static int i2c_mux_pinctrl_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+	return i2c_mux_pinctrl_select(muxc, muxc->num_adapters);
+}
+
+static struct i2c_adapter *i2c_mux_pinctrl_root_adapter(
+	struct pinctrl_state *state)
+{
+	struct i2c_adapter *root = NULL;
+	struct pinctrl_setting *setting;
+	struct i2c_adapter *pin_root;
+
+	list_for_each_entry(setting, &state->settings, node) {
+		pin_root = i2c_root_adapter(setting->pctldev->dev);
+		if (!pin_root)
+			return NULL;
+		if (!root)
+			root = pin_root;
+		else if (root != pin_root)
+			return NULL;
+	}
+
+	return root;
+}
+
+static struct i2c_adapter *i2c_mux_pinctrl_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 int i2c_mux_pinctrl_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct i2c_mux_core *muxc;
+	struct i2c_mux_pinctrl *mux;
+	struct i2c_adapter *parent;
+	struct i2c_adapter *root;
+	int num_names, i, ret;
+	const char *name;
+
+	num_names = of_property_count_strings(np, "pinctrl-names");
+	if (num_names < 0) {
+		dev_err(dev, "Cannot parse pinctrl-names: %d\n",
+			num_names);
+		return num_names;
+	}
+
+	parent = i2c_mux_pinctrl_parent_adapter(dev);
+	if (IS_ERR(parent))
+		return PTR_ERR(parent);
+
+	muxc = i2c_mux_alloc(parent, dev, num_names,
+			     sizeof(*mux) + num_names * sizeof(*mux->states),
+			     0, i2c_mux_pinctrl_select, NULL);
+	if (!muxc) {
+		ret = -ENOMEM;
+		goto err_put_parent;
+	}
+	mux = i2c_mux_priv(muxc);
+	mux->states = (struct pinctrl_state **)(mux + 1);
+
+	platform_set_drvdata(pdev, muxc);
+
+	mux->pinctrl = devm_pinctrl_get(dev);
+	if (IS_ERR(mux->pinctrl)) {
+		ret = PTR_ERR(mux->pinctrl);
+		dev_err(dev, "Cannot get pinctrl: %d\n", ret);
+		goto err_put_parent;
+	}
+
+	for (i = 0; i < num_names; i++) {
+		ret = of_property_read_string_index(np, "pinctrl-names", i,
+						    &name);
+		if (ret < 0) {
+			dev_err(dev, "Cannot parse pinctrl-names: %d\n", ret);
+			goto err_put_parent;
+		}
+
+		mux->states[i] = pinctrl_lookup_state(mux->pinctrl, name);
+		if (IS_ERR(mux->states[i])) {
+			ret = PTR_ERR(mux->states[i]);
+			dev_err(dev, "Cannot look up pinctrl state %s: %d\n",
+				name, ret);
+			goto err_put_parent;
+		}
+
+		if (strcmp(name, "idle"))
+			continue;
+
+		if (i != num_names - 1) {
+			dev_err(dev, "idle state must be last\n");
+			ret = -EINVAL;
+			goto err_put_parent;
+		}
+		muxc->deselect = i2c_mux_pinctrl_deselect;
+	}
+
+	root = i2c_root_adapter(&muxc->parent->dev);
+
+	muxc->mux_locked = true;
+	for (i = 0; i < num_names; i++) {
+		if (root != i2c_mux_pinctrl_root_adapter(mux->states[i])) {
+			muxc->mux_locked = false;
+			break;
+		}
+	}
+	if (muxc->mux_locked)
+		dev_info(dev, "mux-locked i2c mux\n");
+
+	/* Do not add any adapter for the idle state (if it's there at all). */
+	for (i = 0; i < num_names - !!muxc->deselect; i++) {
+		ret = i2c_mux_add_adapter(muxc, 0, i, 0);
+		if (ret)
+			goto err_del_adapter;
+	}
+
+	return 0;
+
+err_del_adapter:
+	i2c_mux_del_adapters(muxc);
+err_put_parent:
+	i2c_put_adapter(parent);
+
+	return ret;
+}
+
+static int i2c_mux_pinctrl_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 const struct of_device_id i2c_mux_pinctrl_of_match[] = {
+	{ .compatible = "i2c-mux-pinctrl", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_pinctrl_of_match);
+
+static struct platform_driver i2c_mux_pinctrl_driver = {
+	.driver	= {
+		.name	= "i2c-mux-pinctrl",
+		.of_match_table = of_match_ptr(i2c_mux_pinctrl_of_match),
+	},
+	.probe	= i2c_mux_pinctrl_probe,
+	.remove	= i2c_mux_pinctrl_remove,
+};
+module_platform_driver(i2c_mux_pinctrl_driver);
+
+MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver");
+MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-mux-pinctrl");