usb: typec: driver for Pericom PI3USB30532 Type-C cross switch

Add a driver for the Pericom PI3USB30532 Type-C cross switch /
mux chip found on some devices with a Type-C port.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -14544,6 +14544,12 @@ F:	drivers/usb/
 F:	include/linux/usb.h
 F:	include/linux/usb/
 
+USB TYPEC PI3USB30532 MUX DRIVER
+M:	Hans de Goede <hdegoede@redhat.com>
+L:	linux-usb@vger.kernel.org
+S:	Maintained
+F:	drivers/usb/typec/mux/pi3usb30532.c
+
 USB TYPEC SUBSYSTEM
 M:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
 L:	linux-usb@vger.kernel.org

drivers/usb/typec/Kconfig

@@ -85,4 +85,6 @@ config TYPEC_TPS6598X
 	  If you choose to build this driver as a dynamically linked module, the
 	  module will be called tps6598x.ko.
 
+source "drivers/usb/typec/mux/Kconfig"
+
 endif # TYPEC

drivers/usb/typec/Makefile

@@ -6,3 +6,4 @@ obj-y				+= fusb302/
 obj-$(CONFIG_TYPEC_WCOVE)	+= typec_wcove.o
 obj-$(CONFIG_TYPEC_UCSI)	+= ucsi/
 obj-$(CONFIG_TYPEC_TPS6598X)	+= tps6598x.o
+obj-$(CONFIG_TYPEC)		+= mux/

drivers/usb/typec/mux/Kconfig

+menu "USB Type-C Multiplexer/DeMultiplexer Switch support"
+
+config TYPEC_MUX_PI3USB30532
+	tristate "Pericom PI3USB30532 Type-C cross switch driver"
+	depends on I2C
+	help
+	  Say Y or M if your system has a Pericom PI3USB30532 Type-C cross
+	  switch / mux chip found on some devices with a Type-C port.
+
+endmenu

drivers/usb/typec/mux/Makefile

+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_TYPEC_MUX_PI3USB30532)	+= pi3usb30532.o

drivers/usb/typec/mux/pi3usb30532.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Pericom PI3USB30532 Type-C cross switch / mux driver
+ *
+ * Copyright (c) 2017-2018 Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/usb/tcpm.h>
+#include <linux/usb/typec_mux.h>
+
+#define PI3USB30532_CONF			0x00
+
+#define PI3USB30532_CONF_OPEN			0x00
+#define PI3USB30532_CONF_SWAP			0x01
+#define PI3USB30532_CONF_4LANE_DP		0x02
+#define PI3USB30532_CONF_USB3			0x04
+#define PI3USB30532_CONF_USB3_AND_2LANE_DP	0x06
+
+struct pi3usb30532 {
+	struct i2c_client *client;
+	struct mutex lock; /* protects the cached conf register */
+	struct typec_switch sw;
+	struct typec_mux mux;
+	u8 conf;
+};
+
+static int pi3usb30532_set_conf(struct pi3usb30532 *pi, u8 new_conf)
+{
+	int ret = 0;
+
+	if (pi->conf == new_conf)
+		return 0;
+
+	ret = i2c_smbus_write_byte_data(pi->client, PI3USB30532_CONF, new_conf);
+	if (ret) {
+		dev_err(&pi->client->dev, "Error writing conf: %d\n", ret);
+		return ret;
+	}
+
+	pi->conf = new_conf;
+	return 0;
+}
+
+static int pi3usb30532_sw_set(struct typec_switch *sw,
+			      enum typec_orientation orientation)
+{
+	struct pi3usb30532 *pi = container_of(sw, struct pi3usb30532, sw);
+	u8 new_conf;
+	int ret;
+
+	mutex_lock(&pi->lock);
+	new_conf = pi->conf;
+
+	switch (orientation) {
+	case TYPEC_ORIENTATION_NONE:
+		new_conf = PI3USB30532_CONF_OPEN;
+		break;
+	case TYPEC_ORIENTATION_NORMAL:
+		new_conf &= ~PI3USB30532_CONF_SWAP;
+		break;
+	case TYPEC_ORIENTATION_REVERSE:
+		new_conf |= PI3USB30532_CONF_SWAP;
+		break;
+	}
+
+	ret = pi3usb30532_set_conf(pi, new_conf);
+	mutex_unlock(&pi->lock);
+
+	return ret;
+}
+
+static int pi3usb30532_mux_set(struct typec_mux *mux, int state)
+{
+	struct pi3usb30532 *pi = container_of(mux, struct pi3usb30532, mux);
+	u8 new_conf;
+	int ret;
+
+	mutex_lock(&pi->lock);
+	new_conf = pi->conf;
+
+	switch (state) {
+	case TYPEC_MUX_NONE:
+		new_conf = PI3USB30532_CONF_OPEN;
+		break;
+	case TYPEC_MUX_USB:
+		new_conf = (new_conf & PI3USB30532_CONF_SWAP) |
+			   PI3USB30532_CONF_USB3;
+		break;
+	case TYPEC_MUX_DP:
+		new_conf = (new_conf & PI3USB30532_CONF_SWAP) |
+			   PI3USB30532_CONF_4LANE_DP;
+		break;
+	case TYPEC_MUX_DOCK:
+		new_conf = (new_conf & PI3USB30532_CONF_SWAP) |
+			   PI3USB30532_CONF_USB3_AND_2LANE_DP;
+		break;
+	}
+
+	ret = pi3usb30532_set_conf(pi, new_conf);
+	mutex_unlock(&pi->lock);
+
+	return ret;
+}
+
+static int pi3usb30532_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct pi3usb30532 *pi;
+	int ret;
+
+	pi = devm_kzalloc(dev, sizeof(*pi), GFP_KERNEL);
+	if (!pi)
+		return -ENOMEM;
+
+	pi->client = client;
+	pi->sw.dev = dev;
+	pi->sw.set = pi3usb30532_sw_set;
+	pi->mux.dev = dev;
+	pi->mux.set = pi3usb30532_mux_set;
+	mutex_init(&pi->lock);
+
+	ret = i2c_smbus_read_byte_data(client, PI3USB30532_CONF);
+	if (ret < 0) {
+		dev_err(dev, "Error reading config register %d\n", ret);
+		return ret;
+	}
+	pi->conf = ret;
+
+	ret = typec_switch_register(&pi->sw);
+	if (ret) {
+		dev_err(dev, "Error registering typec switch: %d\n", ret);
+		return ret;
+	}
+
+	ret = typec_mux_register(&pi->mux);
+	if (ret) {
+		typec_switch_unregister(&pi->sw);
+		dev_err(dev, "Error registering typec mux: %d\n", ret);
+		return ret;
+	}
+
+	i2c_set_clientdata(client, pi);
+	return 0;
+}
+
+static int pi3usb30532_remove(struct i2c_client *client)
+{
+	struct pi3usb30532 *pi = i2c_get_clientdata(client);
+
+	typec_mux_unregister(&pi->mux);
+	typec_switch_unregister(&pi->sw);
+	return 0;
+}
+
+static const struct i2c_device_id pi3usb30532_table[] = {
+	{ "pi3usb30532" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, pi3usb30532_table);
+
+static struct i2c_driver pi3usb30532_driver = {
+	.driver = {
+		.name = "pi3usb30532",
+	},
+	.probe_new	= pi3usb30532_probe,
+	.remove		= pi3usb30532_remove,
+	.id_table	= pi3usb30532_table,
+};
+
+module_i2c_driver(pi3usb30532_driver);
+
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_DESCRIPTION("Pericom PI3USB30532 Type-C mux driver");
+MODULE_LICENSE("GPL");