1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/usb/tcpm/tcpm-uclass.c b/drivers/usb/tcpm/tcpm-uclass.c
new file mode 100644
index 00000000000..d4fe260e0db
--- /dev/null
+++ b/drivers/usb/tcpm/tcpm-uclass.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2024 Collabora Ltd.
+ *
+ * USB Power Delivery protocol stack.
+ */
+
+#include <dm/device.h>
+#include <dm/device_compat.h>
+#include <dm/uclass.h>
+#include <linux/err.h>
+#include <usb/tcpm.h>
+#include "tcpm-internal.h"
+
+int tcpm_get_voltage(struct udevice *dev)
+{
+	struct tcpm_port *port = dev_get_uclass_plat(dev);
+
+	return port->supply_voltage;
+}
+
+int tcpm_get_current(struct udevice *dev)
+{
+	struct tcpm_port *port = dev_get_uclass_plat(dev);
+
+	return port->current_limit;
+}
+
+enum typec_orientation tcpm_get_orientation(struct udevice *dev)
+{
+	struct tcpm_port *port = dev_get_uclass_plat(dev);
+
+	switch (port->polarity) {
+	case TYPEC_POLARITY_CC1:
+		return TYPEC_ORIENTATION_NORMAL;
+	case TYPEC_POLARITY_CC2:
+		return TYPEC_ORIENTATION_REVERSE;
+	default:
+		return TYPEC_ORIENTATION_NONE;
+	}
+}
+
+const char *tcpm_get_state(struct udevice *dev)
+{
+	struct tcpm_port *port = dev_get_uclass_plat(dev);
+
+	return tcpm_states[port->state];
+}
+
+int tcpm_get_pd_rev(struct udevice *dev)
+{
+	struct tcpm_port *port = dev_get_uclass_plat(dev);
+
+	return port->negotiated_rev;
+}
+
+enum typec_role tcpm_get_pwr_role(struct udevice *dev)
+{
+	struct tcpm_port *port = dev_get_uclass_plat(dev);
+
+	return port->pwr_role;
+}
+
+enum typec_data_role tcpm_get_data_role(struct udevice *dev)
+{
+	struct tcpm_port *port = dev_get_uclass_plat(dev);
+
+	return port->data_role;
+}
+
+bool tcpm_is_connected(struct udevice *dev)
+{
+	struct tcpm_port *port = dev_get_uclass_plat(dev);
+
+	return port->connected;
+}
+
+int tcpm_get(int index, struct udevice **devp)
+{
+	return uclass_get_device(UCLASS_TCPM, index, devp);
+}
+
+static int tcpm_post_bind(struct udevice *dev)
+{
+	const struct dm_tcpm_ops *drvops = dev_get_driver_ops(dev);
+	const char *cap_str;
+	ofnode node;
+	int ret;
+
+	/*
+	 * USB Power Delivery (USB PD) specification requires, that communication
+	 * with a sink happens within roughly 5 seconds. Otherwise the source
+	 * might assume that the sink does not support USB PD. Starting to do
+	 * USB PD communication after that results in a hard reset, which briefly
+	 * removes any power from the USB-C port.
+	 *
+	 * On systems with alternative power supplies this is not an issue, but
+	 * systems, which get soleley powered through their USB-C port will end
+	 * up losing their power supply and doing a board level reset. The hard
+	 * reset will also restart the 5 second timeout. That means a operating
+	 * system initializing USB PD will put the system into a boot loop when
+	 * it takes more than 5 seconds from cold boot to the operating system
+	 * starting to transmit USB PD messages.
+	 *
+	 * The issue can be avoided by doing the initial USB PD communication
+	 * in U-Boot. The operating system can then re-negotiate by doing a
+	 * soft reset, which does not trigger removal of the supply voltage.
+	 *
+	 * Since the TCPM state machine is quite complex and depending on the
+	 * remote side can take quite some time to finish, this tries to limit
+	 * the automatic probing to systems probably relying on power being
+	 * provided by the USB-C port(s):
+	 *
+	 * 1. self-powered devices won't reset when the USB-C port looses power
+	 * 2. if the power is allowed to go into anything else than sink mode
+	 *    it is not the only power source
+	 */
+	ret = drvops->get_connector_node(dev, &node);
+	if (ret)
+		return ret;
+
+	if (ofnode_read_bool(node, "self-powered"))
+		return 0;
+
+	cap_str = ofnode_read_string(node, "power-role");
+	if (!cap_str)
+		return -EINVAL;
+
+	if (strcmp("sink", cap_str))
+		return 0;
+
+	/* Do not auto-probe PD controller when PD is disabled */
+	if (ofnode_read_bool(node, "pd-disable"))
+		return 0;
+
+	dev_info(dev, "probing Type-C port manager...");
+
+	dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND);
+
+	return 0;
+}
+
+UCLASS_DRIVER(tcpm) = {
+	.id		= UCLASS_TCPM,
+	.name		= "tcpm",
+	.per_device_plat_auto	= sizeof(struct tcpm_port),
+	.post_bind	= tcpm_post_bind,
+	.post_probe	= tcpm_post_probe,
+};