usb: typec: mux: Add support for the TUSB1046 crosspoint switch

The TUSB1046-DCI is a USB-C linear redriver crosspoint switch, which can
mux SuperSpeed lanes from a Type-C connector to a USB3.0 data lane or up to
4 display port lanes.

Add support for driving the TUSB1046 as a Type-C orientation switch and
DisplayPort altmode multiplexer.

Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20241024-tusb1046-v2-2-d031b1a43e6d@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 213 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index e9659a5a7fb3..3cf9aa8eb647 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23997,6 +23997,13 @@ L:	linux-usb@vger.kernel.org
 S:	Orphan
 F:	drivers/usb/typec/tcpm/
 
+USB TYPEC TUSB1046 MUX DRIVER
+M:	Romain Gantois <romain.gantois@bootlin.com>
+L:	linux-usb@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/usb/ti,tusb1046.yaml
+F:	drivers/usb/typec/mux/tusb1046.c
+
 USB UHCI DRIVER
 M:	Alan Stern <stern@rowland.harvard.edu>
 L:	linux-usb@vger.kernel.org
diff --git a/drivers/usb/typec/mux/Kconfig b/drivers/usb/typec/mux/Kconfig
index ce7db6ad3057..67381b4ef4f6 100644
--- a/drivers/usb/typec/mux/Kconfig
+++ b/drivers/usb/typec/mux/Kconfig
@@ -66,6 +66,15 @@ config TYPEC_MUX_PTN36502
 	  Say Y or M if your system has a NXP PTN36502 Type-C redriver chip
 	  found on some devices with a Type-C port.
 
+config TYPEC_MUX_TUSB1046
+	tristate "TI TUSB1046 Type-C crosspoint switch driver"
+	depends on I2C
+	help
+	  Driver for the Texas Instruments TUSB1046-DCI crosspoint switch.
+	  Supports flipping USB-C SuperSpeed lanes to adapt to orientation
+	  changes, as well as muxing DisplayPort and sideband signals to a
+	  common Type-C connector.
+
 config TYPEC_MUX_WCD939X_USBSS
 	tristate "Qualcomm WCD939x USBSS Analog Audio Switch driver"
 	depends on I2C
diff --git a/drivers/usb/typec/mux/Makefile b/drivers/usb/typec/mux/Makefile
index bb96f30267af..60879446da93 100644
--- a/drivers/usb/typec/mux/Makefile
+++ b/drivers/usb/typec/mux/Makefile
@@ -7,4 +7,5 @@ obj-$(CONFIG_TYPEC_MUX_INTEL_PMC)	+= intel_pmc_mux.o
 obj-$(CONFIG_TYPEC_MUX_IT5205)		+= it5205.o
 obj-$(CONFIG_TYPEC_MUX_NB7VPQ904M)	+= nb7vpq904m.o
 obj-$(CONFIG_TYPEC_MUX_PTN36502)	+= ptn36502.o
+obj-$(CONFIG_TYPEC_MUX_TUSB1046)	+= tusb1046.o
 obj-$(CONFIG_TYPEC_MUX_WCD939X_USBSS)	+= wcd939x-usbss.o
diff --git a/drivers/usb/typec/mux/tusb1046.c b/drivers/usb/typec/mux/tusb1046.c
new file mode 100644
index 000000000000..b4f45c217b59
--- /dev/null
+++ b/drivers/usb/typec/mux/tusb1046.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for the TUSB1046-DCI USB Type-C crosspoint switch
+ *
+ * Copyright (C) 2024 Bootlin
+ */
+
+#include <linux/bits.h>
+#include <linux/i2c.h>
+#include <linux/usb/typec_mux.h>
+#include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_altmode.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/err.h>
+#include <linux/of_device.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+
+#define TUSB1046_REG_GENERAL 0xa
+
+/* General register bits */
+#define TUSB1046_GENERAL_FLIPSEL BIT(2)
+#define TUSB1046_GENERAL_CTLSEL  GENMASK(1, 0)
+
+/* Mux modes */
+#define TUSB1046_CTLSEL_DISABLED          0x0
+#define TUSB1046_CTLSEL_USB3              0x1
+#define TUSB1046_CTLSEL_4LANE_DP          0x2
+#define TUSB1046_CTLSEL_USB3_AND_2LANE_DP 0x3
+
+struct tusb1046_priv {
+	struct i2c_client *client;
+	struct typec_switch_dev *sw;
+	struct typec_mux_dev *mux;
+
+	/* Lock General register during accesses */
+	struct mutex general_reg_lock;
+};
+
+static int tusb1046_mux_set(struct typec_mux_dev *mux,
+			    struct typec_mux_state *state)
+{
+	struct tusb1046_priv *priv = typec_mux_get_drvdata(mux);
+	struct i2c_client *client = priv->client;
+	struct device *dev = &client->dev;
+	int mode, val, ret = 0;
+
+	if (state->mode >= TYPEC_STATE_MODAL &&
+	    state->alt->svid != USB_TYPEC_DP_SID)
+		return -EINVAL;
+
+	dev_dbg(dev, "mux mode requested: %lu\n", state->mode);
+
+	mutex_lock(&priv->general_reg_lock);
+
+	val = i2c_smbus_read_byte_data(client, TUSB1046_REG_GENERAL);
+	if (val < 0) {
+		dev_err(dev, "failed to read ctlsel status, err %d\n", val);
+		ret = val;
+		goto out_unlock;
+	}
+
+	switch (state->mode) {
+	case TYPEC_STATE_USB:
+		mode = TUSB1046_CTLSEL_USB3;
+		break;
+	case TYPEC_DP_STATE_C:
+	case TYPEC_DP_STATE_E:
+		mode = TUSB1046_CTLSEL_4LANE_DP;
+		break;
+	case TYPEC_DP_STATE_D:
+		mode = TUSB1046_CTLSEL_USB3_AND_2LANE_DP;
+		break;
+	case TYPEC_STATE_SAFE:
+	default:
+		mode = TUSB1046_CTLSEL_DISABLED;
+		break;
+	}
+
+	val &= ~TUSB1046_GENERAL_CTLSEL;
+	val |= mode;
+
+	ret = i2c_smbus_write_byte_data(client, TUSB1046_REG_GENERAL, val);
+
+out_unlock:
+	mutex_unlock(&priv->general_reg_lock);
+	return ret;
+}
+
+static int tusb1046_switch_set(struct typec_switch_dev *sw,
+			       enum typec_orientation orientation)
+{
+	struct tusb1046_priv *priv = typec_switch_get_drvdata(sw);
+	struct i2c_client *client = priv->client;
+	struct device *dev = &client->dev;
+	int val, ret = 0;
+
+	dev_dbg(dev, "setting USB3.0 lane flip for orientation %d\n", orientation);
+
+	mutex_lock(&priv->general_reg_lock);
+
+	val = i2c_smbus_read_byte_data(client, TUSB1046_REG_GENERAL);
+	if (val < 0) {
+		dev_err(dev, "failed to read flipsel status, err %d\n", val);
+		ret = val;
+		goto out_unlock;
+	}
+
+	if (orientation == TYPEC_ORIENTATION_REVERSE)
+		val |= TUSB1046_GENERAL_FLIPSEL;
+	else
+		val &= ~TUSB1046_GENERAL_FLIPSEL;
+
+	ret = i2c_smbus_write_byte_data(client, TUSB1046_REG_GENERAL, val);
+
+out_unlock:
+	mutex_unlock(&priv->general_reg_lock);
+	return ret;
+}
+
+static int tusb1046_i2c_probe(struct i2c_client *client)
+{
+	struct typec_switch_desc sw_desc = { };
+	struct typec_mux_desc mux_desc = { };
+	struct device *dev = &client->dev;
+	struct tusb1046_priv *priv;
+	int ret = 0;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return dev_err_probe(dev, -ENOMEM, "failed to allocate driver data\n");
+
+	priv->client = client;
+
+	mutex_init(&priv->general_reg_lock);
+
+	sw_desc.drvdata = priv;
+	sw_desc.fwnode = dev_fwnode(dev);
+	sw_desc.set = tusb1046_switch_set;
+
+	priv->sw = typec_switch_register(dev, &sw_desc);
+	if (IS_ERR(priv->sw)) {
+		ret = dev_err_probe(dev, PTR_ERR(priv->sw), "failed to register type-c switch\n");
+		goto err_destroy_mutex;
+	}
+
+	mux_desc.drvdata = priv;
+	mux_desc.fwnode = dev_fwnode(dev);
+	mux_desc.set = tusb1046_mux_set;
+
+	priv->mux = typec_mux_register(dev, &mux_desc);
+	if (IS_ERR(priv->mux)) {
+		ret = dev_err_probe(dev, PTR_ERR(priv->mux), "failed to register type-c mux\n");
+		goto err_unregister_switch;
+	}
+
+	i2c_set_clientdata(client, priv);
+
+	return 0;
+
+err_unregister_switch:
+	typec_switch_unregister(priv->sw);
+err_destroy_mutex:
+	mutex_destroy(&priv->general_reg_lock);
+	return ret;
+}
+
+static void tusb1046_i2c_remove(struct i2c_client *client)
+{
+	struct tusb1046_priv *priv = i2c_get_clientdata(client);
+
+	typec_switch_unregister(priv->sw);
+	typec_mux_unregister(priv->mux);
+	mutex_destroy(&priv->general_reg_lock);
+}
+
+static const struct of_device_id tusb1046_match_table[] = {
+	{.compatible = "ti,tusb1046"},
+	{},
+};
+
+static struct i2c_driver tusb1046_driver = {
+	.driver = {
+		.name = "tusb1046",
+		.of_match_table = tusb1046_match_table,
+	},
+	.probe = tusb1046_i2c_probe,
+	.remove = tusb1046_i2c_remove,
+};
+
+module_i2c_driver(tusb1046_driver);
+
+MODULE_DESCRIPTION("TUSB1046 USB Type-C switch driver");
+MODULE_AUTHOR("Romain Gantois <romain.gantois@bootlin.com>");
+MODULE_LICENSE("GPL");