libpayload: Add a generic driver for usb hubs

The current drivers for external usb hubs and root hubs all follow
the same pattern. Before adding another one with 90% of the same code,
extract the common parts and rewrite them with a simple interface.

This also adds debouncing of new attachments. Current drivers just
waited 100ms before they reset the device. However, we should check
if the device becomes disconnected and reconnected during this period.

Porting of the current hub drivers will take place in separate
commits (when I have time to test the older HCIs).

Change-Id: I0c0ce0ac1b1cc51fb4cd009b3f9fcd1b9d2ba8fe
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/3450
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

2 files changed, 380 insertions, 0 deletions

diff --git a/payloads/libpayload/drivers/usb/generic_hub.c b/payloads/libpayload/drivers/usb/generic_hub.c
new file mode 100644
index 0000000000..d568d4b8a4
--- /dev/null
+++ b/payloads/libpayload/drivers/usb/generic_hub.c
@@ -0,0 +1,297 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2013 secunet Security Networks AG
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+//#define USB_DEBUG
+
+#include <stdlib.h>
+#include <usb/usb.h>
+#include "generic_hub.h"
+
+void
+generic_hub_destroy(usbdev_t *const dev)
+{
+	generic_hub_t *const hub = GEN_HUB(dev);
+	if (!hub)
+		return;
+
+	/* First, detach all devices behind this hub */
+	int port;
+	for (port = 1; port <= hub->num_ports; ++port) {
+		if (hub->ports[port] >= 0) {
+			usb_debug("generic_hub: Detachment at port %d\n", port);
+			usb_detach_device(dev->controller, hub->ports[port]);
+			hub->ports[port] = NO_DEV;
+		}
+	}
+
+	/* Disable all ports */
+	if (hub->ops->disable_port) {
+		for (port = 1; port <= hub->num_ports; ++port)
+			hub->ops->disable_port(dev, port);
+	}
+
+	free(hub->ports);
+	free(hub);
+}
+
+static int
+generic_hub_debounce(usbdev_t *const dev, const int port)
+{
+	generic_hub_t *const hub = GEN_HUB(dev);
+
+	const int step_ms	= 1;	/* linux uses 25ms, we're busy anyway */
+	const int at_least_ms	= 100;	/* 100ms as in usb20 spec 9.1.2 */
+	const int timeout_ms	= 1500;	/* linux uses this value */
+
+	int total_ms = 0;
+	int stable_ms = 0;
+	while (stable_ms < at_least_ms && total_ms < timeout_ms) {
+		mdelay(step_ms);
+
+		const int changed = hub->ops->port_status_changed(dev, port);
+		const int connected = hub->ops->port_connected(dev, port);
+		if (changed < 0 || connected < 0)
+			return -1;
+
+		if (!changed && connected) {
+			stable_ms += step_ms;
+		} else {
+			usb_debug("generic_hub: Unstable connection at %d\n",
+				  port);
+			stable_ms = 0;
+		}
+		total_ms += step_ms;
+	}
+	if (total_ms >= timeout_ms)
+		usb_debug("generic_hub: Debouncing timed out at %d\n", port);
+	return 0; /* ignore timeouts, try to always go on */
+}
+
+static int
+generic_hub_wait_for_port(usbdev_t *const dev, const int port,
+			  const int wait_for,
+			  int (*const port_op)(usbdev_t *, int),
+			  int timeout_steps, const int step_us)
+{
+	int state;
+	do {
+		state = port_op(dev, port);
+		if (state < 0)
+			return -1;
+		else if (!!state == wait_for)
+			return timeout_steps;
+		udelay(step_us);
+		--timeout_steps;
+	} while (timeout_steps);
+	return 0;
+}
+
+int
+generic_hub_resetport(usbdev_t *const dev, const int port)
+{
+	generic_hub_t *const hub = GEN_HUB(dev);
+
+	if (hub->ops->start_port_reset(dev, port) < 0)
+		return -1;
+
+	/* wait for 10ms (usb20 spec 11.5.1.5: reset should take 10 to 20ms) */
+	mdelay(10);
+
+	/* now wait 12ms for the hub to finish the reset */
+	const int ret = generic_hub_wait_for_port(
+			/* time out after 120 * 100us = 12ms */
+			dev, port, 0, hub->ops->port_in_reset, 120, 100);
+	if (ret < 0)
+		return -1;
+	else if (!ret)
+		usb_debug("generic_hub: Reset timed out at port %d\n", port);
+
+	return 0; /* ignore timeouts, try to always go on */
+}
+
+int
+generic_hub_rh_resetport(usbdev_t *const dev, const int port)
+{
+	generic_hub_t *const hub = GEN_HUB(dev);
+
+	/*
+	 * Resetting a root hub port should hold 50ms with pulses of at
+	 * least 10ms and gaps of at most 3ms (usb20 spec 7.1.7.5).
+	 * After reset, the port will be enabled automatically.
+	 */
+	int total = 500; /* 500 * 100us = 50ms */
+	while (total > 0) {
+		if (hub->ops->start_port_reset(dev, port) < 0)
+			return -1;
+
+		/* wait 100ms for the hub to finish the reset pulse */
+		const int timeout = generic_hub_wait_for_port(
+				/* time out after 1000 * 100us = 100ms */
+				dev, port, 0, hub->ops->port_in_reset, 1000, 100);
+		const int reset_time = 1000 - timeout;
+		if (timeout < 0)
+			return -1;
+		else if (!timeout)
+			usb_debug("generic_hub: Reset timed out at port %d\n",
+				  port);
+		else if (reset_time < 100) /* i.e. < 100 * 100us */
+			usb_debug("generic_hub: Port reset too short\n");
+		total -= reset_time;
+	}
+	return 0; /* ignore timeouts, try to always go on */
+}
+
+static int
+generic_hub_detach_dev(usbdev_t *const dev, const int port)
+{
+	generic_hub_t *const hub = GEN_HUB(dev);
+
+	usb_detach_device(dev->controller, hub->ports[port]);
+	hub->ports[port] = NO_DEV;
+
+	return 0;
+}
+
+static int
+generic_hub_attach_dev(usbdev_t *const dev, const int port)
+{
+	generic_hub_t *const hub = GEN_HUB(dev);
+
+	if (generic_hub_debounce(dev, port) < 0)
+		return -1;
+
+	if (hub->ops->reset_port) {
+		if (hub->ops->reset_port(dev, port) < 0)
+			return -1;
+		/* after reset the port will be enabled automatically */
+		const int ret = generic_hub_wait_for_port(
+			/* time out after 1,000 * 10us = 10ms */
+			dev, port, 1, hub->ops->port_enabled, 1000, 10);
+		if (ret < 0)
+			return -1;
+		else if (!ret)
+			usb_debug("generic_hub: Port %d still "
+				  "disabled after 10ms\n", port);
+	}
+
+	const int speed = hub->ops->port_speed(dev, port);
+	if (speed >= 0) {
+		usb_debug("generic_hub: Success at port %d\n", port);
+		if (hub->ops->reset_port)
+			mdelay(10); /* Reset recovery time
+				       (usb20 spec 7.1.7.5) */
+		hub->ports[port] = usb_attach_device(
+				dev->controller, dev->address, port, speed);
+	}
+	return 0;
+}
+
+int
+generic_hub_scanport(usbdev_t *const dev, const int port)
+{
+	generic_hub_t *const hub = GEN_HUB(dev);
+
+	if (hub->ports[port] >= 0) {
+		usb_debug("generic_hub: Detachment at port %d\n", port);
+
+		const int ret = generic_hub_detach_dev(dev, port);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (hub->ops->port_connected(dev, port)) {
+		usb_debug("generic_hub: Attachment at port %d\n", port);
+
+		return generic_hub_attach_dev(dev, port);
+	}
+
+	return 0;
+}
+
+static void
+generic_hub_poll(usbdev_t *const dev)
+{
+	generic_hub_t *const hub = GEN_HUB(dev);
+	if (!hub)
+		return;
+
+	if (hub->ops->hub_status_changed &&
+			hub->ops->hub_status_changed(dev) != 1)
+		return;
+
+	int port;
+	for (port = 1; port <= hub->num_ports; ++port) {
+		const int ret = hub->ops->port_status_changed(dev, port);
+		if (ret < 0) {
+			return;
+		} else if (ret == 1) {
+			usb_debug("generic_hub: Port change at %d\n", port);
+			if (generic_hub_scanport(dev, port) < 0)
+				return;
+		}
+	}
+}
+
+int
+generic_hub_init(usbdev_t *const dev, const int num_ports,
+		 const generic_hub_ops_t *const ops)
+{
+	int port;
+
+	dev->destroy = generic_hub_destroy;
+	dev->poll = generic_hub_poll;
+	dev->data = malloc(sizeof(generic_hub_t));
+	if (!dev->data) {
+		usb_debug("generic_hub: ERROR: Out of memory\n");
+		return -1;
+	}
+
+	generic_hub_t *const hub = GEN_HUB(dev);
+	hub->num_ports = num_ports;
+	hub->ports = malloc(sizeof(*hub->ports) * (num_ports + 1));
+	hub->ops = ops;
+	if (!hub->ports) {
+		usb_debug("generic_hub: ERROR: Out of memory\n");
+		free(dev->data);
+		dev->data = NULL;
+		return -1;
+	}
+	for (port = 1; port <= num_ports; ++port)
+		hub->ports[port] = NO_DEV;
+
+	/* Enable all ports */
+	if (ops->enable_port) {
+		for (port = 1; port <= num_ports; ++port)
+			ops->enable_port(dev, port);
+		/* wait once for all ports */
+		mdelay(20);
+	}
+
+	return 0;
+}
diff --git a/payloads/libpayload/drivers/usb/generic_hub.h b/payloads/libpayload/drivers/usb/generic_hub.h
new file mode 100644
index 0000000000..7be20e8a9e
--- /dev/null
+++ b/payloads/libpayload/drivers/usb/generic_hub.h
@@ -0,0 +1,83 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2013 secunet Security Networks AG
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef __USB_HUB_H
+#define __USB_HUB_H
+
+#include <usb/usb.h>
+
+typedef struct generic_hub_ops {
+	/* negative results denote an error */
+
+	/* returns 1 if the hub's status changed since the last call (optional) */
+	int (*hub_status_changed)(usbdev_t *);
+	/* returns 1 if the port's status changed since the last call */
+	int (*port_status_changed)(usbdev_t *, int port);
+	/* returns 1 if something is connected to the port */
+	int (*port_connected)(usbdev_t *, int port);
+	/* returns 1 if port is currently resetting */
+	int (*port_in_reset)(usbdev_t *, int port);
+	/* returns 1 if the port is enabled */
+	int (*port_enabled)(usbdev_t *, int port);
+	/* returns speed if port is enabled, negative value if not */
+	int (*port_speed)(usbdev_t *, int port);
+
+	/* enables (powers up) a port (optional) */
+	int (*enable_port)(usbdev_t *, int port);
+	/* disables (powers down) a port (optional) */
+	int (*disable_port)(usbdev_t *, int port);
+	/* starts a port reset (required if reset_port is set to a generic one from below) */
+	int (*start_port_reset)(usbdev_t *, int port);
+
+	/* performs a port reset (optional, generic implementations below) */
+	int (*reset_port)(usbdev_t *, int port);
+} generic_hub_ops_t;
+
+typedef struct generic_hub {
+	int num_ports;
+	/* port numbers are always 1 based,
+	   so we waste one int for convenience */
+	int *ports; /* allocated to sizeof(*ports)*(num_ports+1) */
+#define NO_DEV -1
+
+	const generic_hub_ops_t *ops;
+
+	void *data;
+} generic_hub_t;
+
+void generic_hub_destroy(usbdev_t *);
+int  generic_hub_resetport(usbdev_t *, int port);
+int  generic_hub_rh_resetport(usbdev_t *, int port); /* root hubs have different timing requirements */
+int  generic_hub_scanport(usbdev_t *, int port);
+/* the provided generic_hub_ops struct has to be static */
+int generic_hub_init(usbdev_t *, int num_ports, const generic_hub_ops_t *);
+
+#define GEN_HUB(usbdev) ((generic_hub_t *)(usbdev)->data)
+
+#endif