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From:   Samuel Holland <samuel@sholland.org>
To:     Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Guenter Roeck <linux@roeck-us.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        Samuel Holland <samuel@sholland.org>
Subject: [PATCH v3 4/4] usb: typec: Support the WUSB3801 port controller
Date:   Sun, 13 Feb 2022 23:01:17 -0600
Message-Id: <20220214050118.61015-5-samuel@sholland.org>
In-Reply-To: <20220214050118.61015-1-samuel@sholland.org>
References: <20220214050118.61015-1-samuel@sholland.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

WUSB3801 features a configurable port type, accessory detection, and
plug orientation detection. It provides a hardware "ID" pin output for
compatibility with USB 2.0 OTG PHYs. Add a typec class driver for it.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

Changes in v3:
 - Remove version info printout

Changes in v2:
 - License the driver as GPL 2 only; probably best anyway as I used a
   lot of other drivers/usb/typec code as inspiration
 - Don't try to be clever; use `default` instead of `unreachable`
 - Free the IRQ before unregistering the partner/port

 drivers/usb/typec/Kconfig    |  10 +
 drivers/usb/typec/Makefile   |   1 +
 drivers/usb/typec/wusb3801.c | 437 +++++++++++++++++++++++++++++++++++
 3 files changed, 448 insertions(+)
 create mode 100644 drivers/usb/typec/wusb3801.c

diff --git a/drivers/usb/typec/Kconfig b/drivers/usb/typec/Kconfig
index ab480f38523a..74acde9fc09f 100644
--- a/drivers/usb/typec/Kconfig
+++ b/drivers/usb/typec/Kconfig
@@ -88,6 +88,16 @@ config TYPEC_QCOM_PMIC
 	  It will also enable the VBUS output to connected devices when a
 	  DFP connection is made.
 
+config TYPEC_WUSB3801
+	tristate "Willsemi WUSB3801 Type-C port controller driver"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Say Y or M here if your system has a WUSB3801 Type-C port controller.
+
+	  If you choose to build this driver as a dynamically linked module, the
+	  module will be called wusb3801.ko.
+
 source "drivers/usb/typec/mux/Kconfig"
 
 source "drivers/usb/typec/altmodes/Kconfig"
diff --git a/drivers/usb/typec/Makefile b/drivers/usb/typec/Makefile
index 57870a2bd787..3b722ec28d99 100644
--- a/drivers/usb/typec/Makefile
+++ b/drivers/usb/typec/Makefile
@@ -9,4 +9,5 @@ obj-$(CONFIG_TYPEC_TPS6598X)	+= tipd/
 obj-$(CONFIG_TYPEC_HD3SS3220)	+= hd3ss3220.o
 obj-$(CONFIG_TYPEC_QCOM_PMIC)	+= qcom-pmic-typec.o
 obj-$(CONFIG_TYPEC_STUSB160X) 	+= stusb160x.o
+obj-$(CONFIG_TYPEC_WUSB3801)	+= wusb3801.o
 obj-$(CONFIG_TYPEC)		+= mux/
diff --git a/drivers/usb/typec/wusb3801.c b/drivers/usb/typec/wusb3801.c
new file mode 100644
index 000000000000..e63509f8b01e
--- /dev/null
+++ b/drivers/usb/typec/wusb3801.c
@@ -0,0 +1,437 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Willsemi WUSB3801 Type-C port controller driver
+ *
+ * Copyright (C) 2022 Samuel Holland <samuel@sholland.org>
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/usb/typec.h>
+
+#define WUSB3801_REG_DEVICE_ID		0x01
+#define WUSB3801_REG_CTRL0		0x02
+#define WUSB3801_REG_INT		0x03
+#define WUSB3801_REG_STAT		0x04
+#define WUSB3801_REG_CTRL1		0x05
+#define WUSB3801_REG_TEST00		0x06
+#define WUSB3801_REG_TEST01		0x07
+#define WUSB3801_REG_TEST02		0x08
+#define WUSB3801_REG_TEST03		0x09
+#define WUSB3801_REG_TEST04		0x0a
+#define WUSB3801_REG_TEST05		0x0b
+#define WUSB3801_REG_TEST06		0x0c
+#define WUSB3801_REG_TEST07		0x0d
+#define WUSB3801_REG_TEST08		0x0e
+#define WUSB3801_REG_TEST09		0x0f
+#define WUSB3801_REG_TEST0A		0x10
+#define WUSB3801_REG_TEST0B		0x11
+#define WUSB3801_REG_TEST0C		0x12
+#define WUSB3801_REG_TEST0D		0x13
+#define WUSB3801_REG_TEST0E		0x14
+#define WUSB3801_REG_TEST0F		0x15
+#define WUSB3801_REG_TEST10		0x16
+#define WUSB3801_REG_TEST11		0x17
+#define WUSB3801_REG_TEST12		0x18
+
+#define WUSB3801_DEVICE_ID_VERSION_ID	GENMASK(7, 3)
+#define WUSB3801_DEVICE_ID_VENDOR_ID	GENMASK(2, 0)
+
+#define WUSB3801_CTRL0_DIS_ACC_SUPPORT	BIT(7)
+#define WUSB3801_CTRL0_TRY		GENMASK(6, 5)
+#define WUSB3801_CTRL0_TRY_NONE		(0x0 << 5)
+#define WUSB3801_CTRL0_TRY_SNK		(0x1 << 5)
+#define WUSB3801_CTRL0_TRY_SRC		(0x2 << 5)
+#define WUSB3801_CTRL0_CURRENT		GENMASK(4, 3) /* SRC */
+#define WUSB3801_CTRL0_CURRENT_DEFAULT	(0x0 << 3)
+#define WUSB3801_CTRL0_CURRENT_1_5A	(0x1 << 3)
+#define WUSB3801_CTRL0_CURRENT_3_0A	(0x2 << 3)
+#define WUSB3801_CTRL0_ROLE		GENMASK(2, 1)
+#define WUSB3801_CTRL0_ROLE_SNK		(0x0 << 1)
+#define WUSB3801_CTRL0_ROLE_SRC		(0x1 << 1)
+#define WUSB3801_CTRL0_ROLE_DRP		(0x2 << 1)
+#define WUSB3801_CTRL0_INT_MASK		BIT(0)
+
+#define WUSB3801_INT_ATTACHED		BIT(0)
+#define WUSB3801_INT_DETACHED		BIT(1)
+
+#define WUSB3801_STAT_VBUS_DETECTED	BIT(7)
+#define WUSB3801_STAT_CURRENT		GENMASK(6, 5) /* SNK */
+#define WUSB3801_STAT_CURRENT_STANDBY	(0x0 << 5)
+#define WUSB3801_STAT_CURRENT_DEFAULT	(0x1 << 5)
+#define WUSB3801_STAT_CURRENT_1_5A	(0x2 << 5)
+#define WUSB3801_STAT_CURRENT_3_0A	(0x3 << 5)
+#define WUSB3801_STAT_PARTNER		GENMASK(4, 2)
+#define WUSB3801_STAT_PARTNER_STANDBY	(0x0 << 2)
+#define WUSB3801_STAT_PARTNER_SNK	(0x1 << 2)
+#define WUSB3801_STAT_PARTNER_SRC	(0x2 << 2)
+#define WUSB3801_STAT_PARTNER_AUDIO	(0x3 << 2)
+#define WUSB3801_STAT_PARTNER_DEBUG	(0x4 << 2)
+#define WUSB3801_STAT_ORIENTATION	GENMASK(1, 0)
+#define WUSB3801_STAT_ORIENTATION_NONE	(0x0 << 0)
+#define WUSB3801_STAT_ORIENTATION_CC1	(0x1 << 0)
+#define WUSB3801_STAT_ORIENTATION_CC2	(0x2 << 0)
+#define WUSB3801_STAT_ORIENTATION_BOTH	(0x3 << 0)
+
+#define WUSB3801_CTRL1_SM_RESET		BIT(0)
+
+#define WUSB3801_TEST01_VENDOR_SUB_ID	(BIT(8) | BIT(6))
+
+#define WUSB3801_TEST02_FORCE_ERR_RCY	BIT(8)
+
+#define WUSB3801_TEST0A_WAIT_VBUS	BIT(5)
+
+struct wusb3801 {
+	struct typec_capability	cap;
+	struct device		*dev;
+	struct typec_partner	*partner;
+	struct typec_port	*port;
+	struct regmap		*regmap;
+	struct regulator	*vbus_supply;
+	unsigned int		partner_type;
+	enum typec_port_type	port_type;
+	enum typec_pwr_opmode	pwr_opmode;
+	bool			vbus_on;
+};
+
+static enum typec_role wusb3801_get_default_role(struct wusb3801 *wusb3801)
+{
+	switch (wusb3801->port_type) {
+	case TYPEC_PORT_SRC:
+		return TYPEC_SOURCE;
+	case TYPEC_PORT_SNK:
+		return TYPEC_SINK;
+	case TYPEC_PORT_DRP:
+	default:
+		if (wusb3801->cap.prefer_role == TYPEC_SOURCE)
+			return TYPEC_SOURCE;
+		return TYPEC_SINK;
+	}
+}
+
+static int wusb3801_map_port_type(enum typec_port_type type)
+{
+	switch (type) {
+	case TYPEC_PORT_SRC:
+		return WUSB3801_CTRL0_ROLE_SRC;
+	case TYPEC_PORT_SNK:
+		return WUSB3801_CTRL0_ROLE_SNK;
+	case TYPEC_PORT_DRP:
+	default:
+		return WUSB3801_CTRL0_ROLE_DRP;
+	}
+}
+
+static int wusb3801_map_pwr_opmode(enum typec_pwr_opmode mode)
+{
+	switch (mode) {
+	case TYPEC_PWR_MODE_USB:
+	default:
+		return WUSB3801_CTRL0_CURRENT_DEFAULT;
+	case TYPEC_PWR_MODE_1_5A:
+		return WUSB3801_CTRL0_CURRENT_1_5A;
+	case TYPEC_PWR_MODE_3_0A:
+		return WUSB3801_CTRL0_CURRENT_3_0A;
+	}
+}
+
+static unsigned int wusb3801_map_try_role(int role)
+{
+	switch (role) {
+	case TYPEC_NO_PREFERRED_ROLE:
+	default:
+		return WUSB3801_CTRL0_TRY_NONE;
+	case TYPEC_SINK:
+		return WUSB3801_CTRL0_TRY_SNK;
+	case TYPEC_SOURCE:
+		return WUSB3801_CTRL0_TRY_SRC;
+	}
+}
+
+static enum typec_orientation wusb3801_unmap_orientation(unsigned int status)
+{
+	switch (status & WUSB3801_STAT_ORIENTATION) {
+	case WUSB3801_STAT_ORIENTATION_NONE:
+	case WUSB3801_STAT_ORIENTATION_BOTH:
+	default:
+		return TYPEC_ORIENTATION_NONE;
+	case WUSB3801_STAT_ORIENTATION_CC1:
+		return TYPEC_ORIENTATION_NORMAL;
+	case WUSB3801_STAT_ORIENTATION_CC2:
+		return TYPEC_ORIENTATION_REVERSE;
+	}
+}
+
+static enum typec_pwr_opmode wusb3801_unmap_pwr_opmode(unsigned int status)
+{
+	switch (status & WUSB3801_STAT_CURRENT) {
+	case WUSB3801_STAT_CURRENT_STANDBY:
+	case WUSB3801_STAT_CURRENT_DEFAULT:
+	default:
+		return TYPEC_PWR_MODE_USB;
+	case WUSB3801_STAT_CURRENT_1_5A:
+		return TYPEC_PWR_MODE_1_5A;
+	case WUSB3801_STAT_CURRENT_3_0A:
+		return TYPEC_PWR_MODE_3_0A;
+	}
+}
+
+static int wusb3801_try_role(struct typec_port *port, int role)
+{
+	struct wusb3801 *wusb3801 = typec_get_drvdata(port);
+
+	return regmap_update_bits(wusb3801->regmap, WUSB3801_REG_CTRL0,
+				  WUSB3801_CTRL0_TRY,
+				  wusb3801_map_try_role(role));
+}
+
+static int wusb3801_port_type_set(struct typec_port *port,
+				  enum typec_port_type type)
+{
+	struct wusb3801 *wusb3801 = typec_get_drvdata(port);
+	int ret;
+
+	ret = regmap_update_bits(wusb3801->regmap, WUSB3801_REG_CTRL0,
+				 WUSB3801_CTRL0_ROLE,
+				 wusb3801_map_port_type(type));
+	if (ret)
+		return ret;
+
+	wusb3801->port_type = type;
+
+	return 0;
+}
+
+static const struct typec_operations wusb3801_typec_ops = {
+	.try_role	= wusb3801_try_role,
+	.port_type_set	= wusb3801_port_type_set,
+};
+
+static int wusb3801_hw_init(struct wusb3801 *wusb3801)
+{
+	return regmap_write(wusb3801->regmap, WUSB3801_REG_CTRL0,
+			    wusb3801_map_try_role(wusb3801->cap.prefer_role) |
+			    wusb3801_map_pwr_opmode(wusb3801->pwr_opmode) |
+			    wusb3801_map_port_type(wusb3801->port_type));
+}
+
+static void wusb3801_hw_update(struct wusb3801 *wusb3801)
+{
+	struct typec_port *port = wusb3801->port;
+	struct device *dev = wusb3801->dev;
+	unsigned int partner_type, status;
+	int ret;
+
+	ret = regmap_read(wusb3801->regmap, WUSB3801_REG_STAT, &status);
+	if (ret) {
+		dev_warn(dev, "Failed to read port status: %d\n", ret);
+		status = 0;
+	}
+	dev_dbg(dev, "status = 0x%02x\n", status);
+
+	partner_type = status & WUSB3801_STAT_PARTNER;
+
+	if (partner_type == WUSB3801_STAT_PARTNER_SNK) {
+		if (!wusb3801->vbus_on) {
+			ret = regulator_enable(wusb3801->vbus_supply);
+			if (ret)
+				dev_warn(dev, "Failed to enable VBUS: %d\n", ret);
+			wusb3801->vbus_on = true;
+		}
+	} else {
+		if (wusb3801->vbus_on) {
+			regulator_disable(wusb3801->vbus_supply);
+			wusb3801->vbus_on = false;
+		}
+	}
+
+	if (partner_type != wusb3801->partner_type) {
+		struct typec_partner_desc desc = {};
+		enum typec_data_role data_role;
+		enum typec_role pwr_role = wusb3801_get_default_role(wusb3801);
+
+		switch (partner_type) {
+		case WUSB3801_STAT_PARTNER_STANDBY:
+			break;
+		case WUSB3801_STAT_PARTNER_SNK:
+			pwr_role = TYPEC_SOURCE;
+			break;
+		case WUSB3801_STAT_PARTNER_SRC:
+			pwr_role = TYPEC_SINK;
+			break;
+		case WUSB3801_STAT_PARTNER_AUDIO:
+			desc.accessory = TYPEC_ACCESSORY_AUDIO;
+			break;
+		case WUSB3801_STAT_PARTNER_DEBUG:
+			desc.accessory = TYPEC_ACCESSORY_DEBUG;
+			break;
+		}
+
+		if (wusb3801->partner) {
+			typec_unregister_partner(wusb3801->partner);
+			wusb3801->partner = NULL;
+		}
+
+		if (partner_type != WUSB3801_STAT_PARTNER_STANDBY) {
+			wusb3801->partner = typec_register_partner(port, &desc);
+			if (IS_ERR(wusb3801->partner))
+				dev_err(dev, "Failed to register partner: %ld\n",
+					PTR_ERR(wusb3801->partner));
+		}
+
+		data_role = pwr_role == TYPEC_SOURCE ? TYPEC_HOST : TYPEC_DEVICE;
+		typec_set_data_role(port, data_role);
+		typec_set_pwr_role(port, pwr_role);
+		typec_set_vconn_role(port, pwr_role);
+	}
+
+	typec_set_pwr_opmode(wusb3801->port,
+			     partner_type == WUSB3801_STAT_PARTNER_SRC
+				? wusb3801_unmap_pwr_opmode(status)
+				: wusb3801->pwr_opmode);
+	typec_set_orientation(wusb3801->port,
+			      wusb3801_unmap_orientation(status));
+
+	wusb3801->partner_type = partner_type;
+}
+
+static irqreturn_t wusb3801_irq(int irq, void *data)
+{
+	struct wusb3801 *wusb3801 = data;
+	unsigned int dummy;
+
+	/*
+	 * The interrupt register must be read in order to clear the IRQ,
+	 * but all of the useful information is in the status register.
+	 */
+	regmap_read(wusb3801->regmap, WUSB3801_REG_INT, &dummy);
+
+	wusb3801_hw_update(wusb3801);
+
+	return IRQ_HANDLED;
+}
+
+static const struct regmap_config config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.max_register	= WUSB3801_REG_TEST12,
+};
+
+static int wusb3801_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct fwnode_handle *connector;
+	struct wusb3801 *wusb3801;
+	const char *cap_str;
+	int ret;
+
+	wusb3801 = devm_kzalloc(dev, sizeof(*wusb3801), GFP_KERNEL);
+	if (!wusb3801)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, wusb3801);
+
+	wusb3801->dev = dev;
+
+	wusb3801->regmap = devm_regmap_init_i2c(client, &config);
+	if (IS_ERR(wusb3801->regmap))
+		return PTR_ERR(wusb3801->regmap);
+
+	wusb3801->vbus_supply = devm_regulator_get(dev, "vbus");
+	if (IS_ERR(wusb3801->vbus_supply))
+		return PTR_ERR(wusb3801->vbus_supply);
+
+	connector = device_get_named_child_node(dev, "connector");
+	if (!connector)
+		return -ENODEV;
+
+	ret = typec_get_fw_cap(&wusb3801->cap, connector);
+	if (ret)
+		goto err_put_connector;
+	wusb3801->port_type = wusb3801->cap.type;
+
+	ret = fwnode_property_read_string(connector, "typec-power-opmode", &cap_str);
+	if (ret)
+		goto err_put_connector;
+
+	ret = typec_find_pwr_opmode(cap_str);
+	if (ret < 0 || ret == TYPEC_PWR_MODE_PD)
+		goto err_put_connector;
+	wusb3801->pwr_opmode = ret;
+
+	/* Initialize the hardware with the devicetree settings. */
+	ret = wusb3801_hw_init(wusb3801);
+	if (ret)
+		return ret;
+
+	wusb3801->cap.revision		= USB_TYPEC_REV_1_2;
+	wusb3801->cap.accessory[0]	= TYPEC_ACCESSORY_AUDIO;
+	wusb3801->cap.accessory[1]	= TYPEC_ACCESSORY_DEBUG;
+	wusb3801->cap.orientation_aware	= true;
+	wusb3801->cap.driver_data	= wusb3801;
+	wusb3801->cap.ops		= &wusb3801_typec_ops;
+
+	wusb3801->port = typec_register_port(dev, &wusb3801->cap);
+	if (IS_ERR(wusb3801->port)) {
+		ret = PTR_ERR(wusb3801->port);
+		goto err_put_connector;
+	}
+
+	/* Initialize the port attributes from the hardware state. */
+	wusb3801_hw_update(wusb3801);
+
+	ret = request_threaded_irq(client->irq, NULL, wusb3801_irq,
+				   IRQF_ONESHOT, dev_name(dev), wusb3801);
+	if (ret)
+		goto err_unregister_port;
+
+	fwnode_handle_put(connector);
+
+	return 0;
+
+err_unregister_port:
+	typec_unregister_port(wusb3801->port);
+err_put_connector:
+	fwnode_handle_put(connector);
+
+	return ret;
+}
+
+static int wusb3801_remove(struct i2c_client *client)
+{
+	struct wusb3801 *wusb3801 = i2c_get_clientdata(client);
+
+	free_irq(client->irq, wusb3801);
+
+	if (wusb3801->partner)
+		typec_unregister_partner(wusb3801->partner);
+	typec_unregister_port(wusb3801->port);
+
+	if (wusb3801->vbus_on)
+		regulator_disable(wusb3801->vbus_supply);
+
+	return 0;
+}
+
+static const struct of_device_id wusb3801_of_match[] = {
+	{ .compatible = "willsemi,wusb3801" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, wusb3801_of_match);
+
+static struct i2c_driver wusb3801_driver = {
+	.probe_new	= wusb3801_probe,
+	.remove		= wusb3801_remove,
+	.driver		= {
+		.name		= "wusb3801",
+		.of_match_table	= wusb3801_of_match,
+	},
+};
+
+module_i2c_driver(wusb3801_driver);
+
+MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
+MODULE_DESCRIPTION("Willsemi WUSB3801 Type-C port controller driver");
+MODULE_LICENSE("GPL");
-- 
2.33.1