system76-coreboot/payloads/libpayload/drivers/usb/usbhub.c

/*
 * 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 <usb/usb.h>
#include "generic_hub.h"

/* assume that host_to_device is overwritten if necessary */
#define DR_PORT gen_bmRequestType(host_to_device, class_type, other_recp)
/* status (and status change) bits */
#define PORT_CONNECTION		0x01
#define PORT_ENABLE		0x02
#define PORT_SUSPEND		0x04
#define PORT_OVER_CURRENT	0x08
#define PORT_RESET		0x10
#define BH_PORT_RESET		0x20
#define PORT_LINK_STATE		0x40
#define PORT_CONFIG_ERROR	0x80
/* feature selectors (for setting / clearing features) */
#define SEL_PORT_RESET		0x04
#define SEL_PORT_POWER		0x08
#define SEL_C_PORT_CONNECTION	0x10
#define SEL_C_PORT_ENABLE	0x11
#define SEL_C_PORT_SUSPEND	0x12
#define SEL_C_PORT_OVER_CURRENT	0x13
#define SEL_C_PORT_RESET	0x14
#define SEL_C_PORT_LINK_STATE	0x19
#define SEL_C_PORT_CONFIG_ERROR	0x1a
#define SEL_C_BH_PORT_RESET	0x1d
/* request type (USB 3.0 hubs only) */
#define SET_HUB_DEPTH		12

static endpoint_t *
usb_hub_interrupt_ep(usbdev_t *const dev)
{
	int i;
	for (i = 0; i < dev->num_endp; ++i) {
		if (dev->endpoints[i].type == INTERRUPT &&
				dev->endpoints[i].direction == IN)
			return &dev->endpoints[i];
	}
	return NULL;
}

static int
usb_hub_port_status_changed(usbdev_t *const dev, const int port)
{
	unsigned short buf[2];
	int ret = get_status (dev, port, DR_PORT, sizeof(buf), buf);
	if (ret >= 0) {
		ret = buf[1] & PORT_CONNECTION;
		if (ret)
			clear_feature (dev, port, SEL_C_PORT_CONNECTION,
				       DR_PORT);
	}
	return ret;
}

static int
usb_hub_port_connected(usbdev_t *const dev, const int port)
{
	unsigned short buf[2];
	int ret = get_status (dev, port, DR_PORT, sizeof(buf), buf);
	if (ret >= 0)
		ret = buf[0] & PORT_CONNECTION;
	return ret;
}

static int
usb_hub_port_in_reset(usbdev_t *const dev, const int port)
{
	unsigned short buf[2];
	int ret = get_status (dev, port, DR_PORT, sizeof(buf), buf);
	if (ret >= 0)
		ret = buf[0] & PORT_RESET;
	return ret;
}

static int
usb_hub_port_enabled(usbdev_t *const dev, const int port)
{
	unsigned short buf[2];
	int ret = get_status (dev, port, DR_PORT, sizeof(buf), buf);
	if (ret >= 0)
		ret = buf[0] & PORT_ENABLE;
	return ret;
}

static usb_speed
usb_hub_port_speed(usbdev_t *const dev, const int port)
{
	unsigned short buf[2];
	int ret = get_status (dev, port, DR_PORT, sizeof(buf), buf);
	if (ret >= 0 && (buf[0] & PORT_ENABLE)) {
		/* SuperSpeed hubs can only have SuperSpeed devices. */
		if (is_usb_speed_ss(dev->speed))
			return dev->speed;

		/*[bit] 10  9  (USB 2.0 port status word)
		 *      0   0  full speed
		 *      0   1  low speed
		 *      1   0  high speed
		 *      1   1  invalid
		 */
		ret = (buf[0] >> 9) & 0x3;
		if (ret != 0x3)
			return ret;
	}
	return -1;
}

static int
usb_hub_enable_port(usbdev_t *const dev, const int port)
{
	return set_feature(dev, port, SEL_PORT_POWER, DR_PORT);
}

static int
usb_hub_start_port_reset(usbdev_t *const dev, const int port)
{
	return set_feature (dev, port, SEL_PORT_RESET, DR_PORT);
}

static void usb_hub_set_hub_depth(usbdev_t *const dev)
{
	dev_req_t dr = {
		.bmRequestType = gen_bmRequestType(host_to_device,
						   class_type, dev_recp),
		.bRequest = SET_HUB_DEPTH,
		.wValue = 0,
		.wIndex = 0,
		.wLength = 0,
	};
	usbdev_t *parent = dev;
	while (parent->hub > 0) {
		parent = dev->controller->devices[parent->hub];
		dr.wValue++;
	}
	int ret = dev->controller->control(dev, OUT, sizeof(dr), &dr, 0, NULL);
	if (ret < 0)
		usb_debug("Failed SET_HUB_DEPTH(%d) on hub %d: %d\n",
			  dr.wValue, dev->address, ret);
}

static const generic_hub_ops_t usb_hub_ops = {
	.hub_status_changed	= NULL,
	.port_status_changed	= usb_hub_port_status_changed,
	.port_connected		= usb_hub_port_connected,
	.port_in_reset		= usb_hub_port_in_reset,
	.port_enabled		= usb_hub_port_enabled,
	.port_speed		= usb_hub_port_speed,
	.enable_port		= usb_hub_enable_port,
	.disable_port		= NULL,
	.start_port_reset	= usb_hub_start_port_reset,
	.reset_port		= generic_hub_resetport,
};

/* Clear CSC if set and enumerate port if it's connected regardless of change
   bits. Some broken hubs don't set CSC if already connected during reset. */
static void
usb_hub_port_initialize(usbdev_t *const dev, const int port)
{
	unsigned short buf[2];
	int ret = get_status(dev, port, DR_PORT, sizeof(buf), buf);
	if (ret < 0)
		return;
	if (buf[1] & PORT_CONNECTION)
		clear_feature(dev, port, SEL_C_PORT_CONNECTION, DR_PORT);
	if (buf[0] & PORT_CONNECTION) {
		usb_debug("usbhub: Port coldplug at %d\n", port);
		generic_hub_scanport(dev, port);
	}
}

static int
usb_hub_handle_port_change(usbdev_t *const dev, const int port)
{
	static const struct {
		unsigned short change_bit;
		unsigned short clear_sel;
	} change_bits[] = {
		{ PORT_CONNECTION,	SEL_C_PORT_CONNECTION	},
		{ PORT_ENABLE,		SEL_C_PORT_ENABLE	},
		{ PORT_SUSPEND,		SEL_C_PORT_SUSPEND	},
		{ PORT_OVER_CURRENT,	SEL_C_PORT_OVER_CURRENT	},
		{ PORT_RESET,		SEL_C_PORT_RESET	},
		{ BH_PORT_RESET,	SEL_C_BH_PORT_RESET	},
		{ PORT_LINK_STATE,	SEL_C_PORT_LINK_STATE	},
		{ PORT_CONFIG_ERROR,	SEL_C_PORT_CONFIG_ERROR	},
	};
	int ret = 0;
	unsigned int i;
	unsigned short checked_bits = 0;
	unsigned short buf[2] = { 0, 0 };

	ret = get_status(dev, port, DR_PORT, sizeof(buf), buf);
	if (ret < 0)
		return ret;

	/*
	 * Second word holds the change bits. The interrupt transfer shows
	 * a logical or of these bits, so we have to clear them all.
	 */
	for (i = 0; i < ARRAY_SIZE(change_bits); ++i) {
		if (buf[1] & change_bits[i].change_bit)
			clear_feature(dev, port, change_bits[i].clear_sel, DR_PORT);
		checked_bits |= change_bits[i].change_bit;
	}
	if (buf[1] & ~checked_bits)
		usb_debug("usbhub: Spurious change bit at port %d\n", port);

	/* Now, handle connection changes. */
	if (buf[1] & PORT_CONNECTION) {
		usb_debug("usbhub: Port change at %d\n", port);
		ret = generic_hub_scanport(dev, port);
	}
	return ret;
}

static void
usb_hub_poll(usbdev_t *const dev)
{
	unsigned int port, i;
	u8 buf[32] = { 0 };
	const u8 *ibuf;

	/* First, gather all change bits from finished interrupt transfers. */
	const size_t port_bytes = MIN(ARRAY_SIZE(buf),
			div_round_up(GEN_HUB(dev)->num_ports + 1, 8));
	while ((ibuf = dev->controller->poll_intr_queue(GEN_HUB(dev)->data))) {
		for (i = 0; i < port_bytes; ++i)
			buf[i] |= ibuf[i];
	}

	for (port = 1; port <= GEN_HUB(dev)->num_ports; ++port) {
		/* ports start at bit1; bit0 is hub status change */
		if (buf[port / 8] & (1 << (port % 8))) {
			if (usb_hub_handle_port_change(dev, port) < 0)
				return;
		}
	}
}

static void
usb_hub_destroy(usbdev_t *const dev)
{
	endpoint_t *const intr_ep = usb_hub_interrupt_ep(dev);
	dev->controller->destroy_intr_queue(intr_ep, GEN_HUB(dev)->data);
	generic_hub_destroy(dev);
}

void
usb_hub_init(usbdev_t *const dev)
{
	endpoint_t *const intr_ep = usb_hub_interrupt_ep(dev);
	if (!intr_ep) {
		usb_debug("usbhub: ERROR: No interrupt-in endpoint found\n");
		return;
	}

	/* Get number of ports from hub descriptor */
	int type = is_usb_speed_ss(dev->speed) ? 0x2a : 0x29; /* similar enough */
	hub_descriptor_t desc;	/* won't fit the whole thing, we don't care */
	if (get_descriptor(dev, gen_bmRequestType(device_to_host, class_type,
		dev_recp), type, 0, &desc, sizeof(desc)) != sizeof(desc)) {
		usb_debug("get_descriptor(HUB) failed\n");
		usb_detach_device(dev->controller, dev->address);
		return;
	}

	if (is_usb_speed_ss(dev->speed))
		usb_hub_set_hub_depth(dev);

	/*
	 * Register interrupt transfer:
	 *   one bit per port + one bit for the hub,
	 *   20 transfers in the queue, like our HID driver,
	 *   one transfer per 256ms
	 */
	void *const intrq = dev->controller->create_intr_queue(
			intr_ep, intr_ep->maxpacketsize, 20, 256);
	if (!intrq) {
		usb_detach_device(dev->controller, dev->address);
		return;
	}

	/*
	 * Limit the number of ports by the max packet size of
	 * the interrupt endpoint. This shouldn't be necessary
	 * but prevents a potential overflow in usb_hub_poll().
	 */
	const unsigned int num_ports =
		MIN(desc.bNbrPorts, intr_ep->maxpacketsize * 8 - 1);
	if (generic_hub_init(dev, num_ports, &usb_hub_ops)) {
		dev->controller->destroy_intr_queue(intr_ep, intrq);
		usb_detach_device(dev->controller, dev->address);
		return;
	}

	int port;
	for (port = 1; port <= num_ports; ++port)
		usb_hub_port_initialize(dev, port);

	GEN_HUB(dev)->data = intrq;
	dev->poll = usb_hub_poll;
	dev->destroy = usb_hub_destroy;
}