Add an EHCI driver to libpayload's USB stack.

Interrupt transfer support is missing (ie. no keyboard),
bulk and control transfers work (ie. mass storage).

Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>
Acked-by: Peter Stuge <peter@stuge.se>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5845 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

5 files changed, 812 insertions, 3 deletions

diff --git a/payloads/libpayload/drivers/usb/ehci.c b/payloads/libpayload/drivers/usb/ehci.c
new file mode 100644
index 0000000000..93cc00ced1
--- /dev/null
+++ b/payloads/libpayload/drivers/usb/ehci.c
@@ -0,0 +1,359 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2010 coresystems GmbH
+ *
+ * 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.
+ */
+
+#include <libpayload.h>
+#include "ehci.h"
+#include "ehci_private.h"
+
+static void dump_td(u32 addr) {
+	qtd_t *td = phys_to_virt(addr);
+	printf("td at phys(%x): active: %x, halted: %x, data_buf_err: %x\n    babble: %x, xact_err: %x, missed_mframe: %x\n    splitxstate: %x, perr: %x\n\n",
+		addr, td->active, td->halted, td->data_buf_err, td->babble, td->xact_err, td->missed_mframe, td->splitxstate, td->perr);
+	printf("-   cerr: %x, total_len: %x\n\n", td->cerr, td->total_len);
+}
+
+static void ehci_start (hci_t *controller)
+{
+	EHCI_INST(controller)->operation->rs = 1;
+}
+
+static void ehci_stop (hci_t *controller)
+{
+	EHCI_INST(controller)->operation->rs = 0;
+}
+
+static void ehci_reset (hci_t *controller)
+{
+
+}
+
+static void ehci_shutdown (hci_t *controller)
+{
+
+}
+
+enum { EHCI_OUT=0, EHCI_IN=1, EHCI_SETUP=2 };
+
+/* returns handled bytes */
+int fill_td(qtd_t *td, void* data, int datalen) {
+	u32 total_len = 0;
+	u32 page_minus_1 = 0;
+
+	u32 start = virt_to_phys(data);
+	u32 page = start & ~4095;
+	u32 offset = start & 4095;
+	u32 page_len = 4096 - offset;
+
+	td->c_page = 0;
+	td->bufptr0 = page;
+	td->cur_off = offset;
+
+	if (datalen <= page_len) {
+		total_len = datalen;
+	} else {
+		datalen -= page_len;
+		total_len += page_len;
+
+		do {
+			/* we have a continguous mapping between virtual and physical memory */
+			page += 4096;
+
+			td->bufptrs[page_minus_1] = page;
+			if (datalen <= 4096) {
+				total_len += datalen;
+				break;
+			}
+			page_minus_1++;
+			datalen -= 4096;
+			total_len += 4096;
+		} while (page_minus_1<4);
+	}
+	td->total_len = total_len;
+	return total_len;
+}
+
+/* free up data structures */
+void free_qh_and_tds(ehci_qh_t *qh, qtd_t *cur) {
+	qtd_t *next;
+	while (cur) {
+		next = (qtd_t*)phys_to_virt(cur->next_qtd & ~31);
+		free(cur);
+		cur = next;
+	}
+	free(qh);
+}
+
+int wait_for_tds(qtd_t *head) {
+	int result = 0;
+	qtd_t *cur = head;
+	while (1) {
+		if (0) dump_td(virt_to_phys(cur));
+		while (cur->active && !cur->halted) udelay(60);
+		if (cur->halted) {
+			printf("ERROR with packet\n");
+			dump_td(virt_to_phys(cur));
+			printf("-----------------\n");
+			return 1;
+		}
+		if (cur->next_qtd & 1) {
+			return 0;
+		}
+		if (0) dump_td(virt_to_phys(cur));
+		/* helps debugging the TD chain */
+		if (0) printf("\nmoving from %x to %x\n", cur, phys_to_virt(cur->next_qtd));
+		cur = phys_to_virt(cur->next_qtd);
+	}
+	return result;
+}
+
+static int ehci_bulk (endpoint_t *ep, int size, u8 *data, int finalize)
+{
+	int result = 0;
+	int endp = ep->endpoint & 0xf;
+	int pid = (ep->direction==IN)?EHCI_IN:EHCI_OUT;
+
+	qtd_t *head = memalign(32, sizeof(qtd_t));
+	qtd_t *cur = head;
+	while (1) {
+		memset(cur, 0, sizeof(qtd_t));
+		cur->active = 1;
+		cur->pid = pid;
+		cur->cerr = 0;
+		u32 chunk = fill_td(cur, data, size);
+		size -= chunk;
+		data += chunk;
+
+		cur->alt_terminate = 1;
+		if (size == 0) {
+			cur->next_qtd = virt_to_phys(0);
+			cur->terminate = 1;
+			break;
+		} else {
+			qtd_t *next = memalign(32, sizeof(qtd_t));
+			cur->next_qtd = virt_to_phys(next);
+			cur = next;
+		}
+	}
+
+	/* create QH */
+	ehci_qh_t *qh = memalign(32, sizeof(ehci_qh_t));
+	memset(qh, 0, sizeof(ehci_qh_t));
+	qh->horiz_link_ptr = virt_to_phys(qh);
+	qh->type = 1; // FIXME: proper symbols for type. this is QH
+	qh->addr = ep->dev->address;
+	qh->ep = endp;
+	qh->eps = ep->dev->speed;
+	qh->dtc = 0;
+	qh->reclaim_head = 1;
+	qh->max_packet_len = ep->maxpacketsize;
+	qh->nak_cnt_reload = 0;
+	qh->pipe_multiplier = 3;
+
+	qh->td.next_qtd = virt_to_phys(head);
+	qh->td.dt = ep->toggle;
+	head->dt = ep->toggle;
+
+	/* hook up QH */
+	EHCI_INST(ep->dev->controller)->operation->asynclistaddr = virt_to_phys(qh);
+
+	/* start async schedule */
+	EHCI_INST(ep->dev->controller)->operation->async_sched_enable = 1;
+	while (!EHCI_INST(ep->dev->controller)->operation->async_sched_status) ; /* wait */
+
+	/* wait for result */
+	result = wait_for_tds(head);
+
+	/* disable async schedule */
+	EHCI_INST(ep->dev->controller)->operation->async_sched_enable = 0;
+	while (EHCI_INST(ep->dev->controller)->operation->async_sched_status) ; /* wait */
+
+	ep->toggle = cur->dt;
+
+	free_qh_and_tds(qh, head);
+	return result;
+}
+
+
+/* FIXME: Handle control transfers as 3 QHs, so the 2nd stage can be >0x4000 bytes */
+static int ehci_control (usbdev_t *dev, direction_t dir, int drlen, void *devreq,
+			 int dalen, u8 *data)
+{
+	int endp = 0; // this is control. always 0 (for now)
+	int toggle = 0;
+	int mlen = dev->endpoints[0].maxpacketsize;
+	int result = 0;
+
+	/* create qTDs */
+	qtd_t *head = memalign(32, sizeof(qtd_t));
+	qtd_t *cur = head;
+	memset(cur, 0, sizeof(qtd_t));
+	cur->active = 1;
+	cur->dt = toggle;
+	cur->pid = EHCI_SETUP;
+	cur->cerr = 3;
+	if (fill_td(cur, devreq, drlen) != drlen) {
+		printf("ERROR: couldn't send the entire device request\n");
+	}
+	qtd_t *next = memalign(32, sizeof(qtd_t));
+	cur->next_qtd = virt_to_phys(next);
+	cur->alt_terminate = 1;
+
+	/* FIXME: We're limited to 16-20K (depending on alignment) for payload for now.
+	 * Figure out, how toggle can be set sensibly in this scenario */
+	if (dalen > 0) {
+		toggle ^= 1;
+		cur = next;
+		memset(cur, 0, sizeof(qtd_t));
+		cur->active = 1;
+		cur->dt = toggle;
+		cur->pid = (dir == OUT)?EHCI_OUT:EHCI_IN;
+		cur->cerr = 3;
+		if (fill_td(cur, data, dalen) != dalen) {
+			printf("ERROR: couldn't send the entire control payload\n");
+		}
+		next = memalign(32, sizeof(qtd_t));
+		cur->next_qtd = virt_to_phys(next);
+		cur->alt_terminate = 1;
+	}
+
+	toggle = 1;
+	cur = next;
+	memset(cur, 0, sizeof(qtd_t));
+	cur->active = 1;
+	cur->dt = toggle;
+	cur->pid = (dir == OUT)?EHCI_IN:EHCI_OUT;
+	cur->cerr = 0;
+	fill_td(cur, NULL, 0);
+	cur->next_qtd = virt_to_phys(0);
+	cur->terminate = 1;
+	cur->alt_terminate = 1;
+
+	/* create QH */
+	ehci_qh_t *qh = memalign(32, sizeof(ehci_qh_t));
+	memset(qh, 0, sizeof(ehci_qh_t));
+	qh->horiz_link_ptr = virt_to_phys(qh);
+	qh->type = 1; // FIXME: proper symbols for type. this is QH
+	qh->addr = dev->address;
+	qh->ep = endp;
+	qh->eps = dev->speed;
+	qh->dtc = 1; /* Take data toggle from TD, as control transfers are special */
+	qh->reclaim_head = 1;
+	qh->max_packet_len = mlen;
+	qh->non_hs_control_ep = 0; // no support for non-HS devices at this time
+	qh->nak_cnt_reload = 0;
+	qh->pipe_multiplier = 3;
+	qh->td.next_qtd = virt_to_phys(head);
+
+	/* hook up QH */
+	EHCI_INST(dev->controller)->operation->asynclistaddr = virt_to_phys(qh);
+
+	/* start async schedule */
+	EHCI_INST(dev->controller)->operation->async_sched_enable = 1;
+	while (!EHCI_INST(dev->controller)->operation->async_sched_status) ; /* wait */
+
+	result = wait_for_tds(head);
+
+	/* disable async schedule */
+	EHCI_INST(dev->controller)->operation->async_sched_enable = 0;
+	while (EHCI_INST(dev->controller)->operation->async_sched_status) ; /* wait */
+
+	free_qh_and_tds(qh, head);
+	return result;
+}
+
+static void* ehci_create_intr_queue (endpoint_t *ep, int reqsize, int reqcount, int reqtiming)
+{
+	return NULL;
+}
+
+static void ehci_destroy_intr_queue (endpoint_t *ep, void *queue)
+{
+}
+
+static u8* ehci_poll_intr_queue (void *queue)
+{
+	return NULL;
+}
+
+hci_t *
+ehci_init (pcidev_t addr)
+{
+	int i;
+	hci_t *controller = new_controller ();
+
+	if (!controller)
+		usb_fatal("Could not create USB controller instance.\n");
+
+	controller->instance = malloc (sizeof (ehci_t));
+	if(!controller->instance)
+		usb_fatal("Not enough memory creating USB controller instance.\n");
+
+#define PCI_COMMAND 4
+#define PCI_COMMAND_IO 1
+#define PCI_COMMAND_MEMORY 2
+#define PCI_COMMAND_MASTER 4
+
+	u32 pci_command = pci_read_config32(addr, PCI_COMMAND);
+	pci_command = (pci_command | PCI_COMMAND_MEMORY) & ~PCI_COMMAND_IO ;
+	pci_write_config32(addr, PCI_COMMAND, pci_command);
+
+	controller->start = ehci_start;
+	controller->stop = ehci_stop;
+	controller->reset = ehci_reset;
+	controller->shutdown = ehci_shutdown;
+	controller->bulk = ehci_bulk;
+	controller->control = ehci_control;
+	controller->create_intr_queue = ehci_create_intr_queue;
+	controller->destroy_intr_queue = ehci_destroy_intr_queue;
+	controller->poll_intr_queue = ehci_poll_intr_queue;
+	for (i = 0; i < 128; i++) {
+		controller->devices[i] = 0;
+	}
+	init_device_entry (controller, 0);
+
+	EHCI_INST(controller)->capabilities = phys_to_virt(pci_read_config32(addr, USBBASE));
+	EHCI_INST(controller)->operation = (hc_op_t *)(phys_to_virt(pci_read_config32(addr, USBBASE)) + EHCI_INST(controller)->capabilities->caplength);
+
+	/* default value for frame length adjust */
+	pci_write_config8(addr, FLADJ, FLADJ_framelength(60000));
+
+	/* Enable operation of controller */
+	controller->start(controller);
+
+	/* take over all ports. USB1 should be blind now */
+	EHCI_INST(controller)->operation->configflag = 1;
+
+	/* TODO lots of stuff missing */
+
+	controller->devices[0]->controller = controller;
+	controller->devices[0]->init = ehci_rh_init;
+	controller->devices[0]->init (controller->devices[0]);
+
+	return controller;
+}
diff --git a/payloads/libpayload/drivers/usb/ehci.h b/payloads/libpayload/drivers/usb/ehci.h
new file mode 100644
index 0000000000..c66643c702
--- /dev/null
+++ b/payloads/libpayload/drivers/usb/ehci.h
@@ -0,0 +1,40 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2010 coresystems GmbH
+ *
+ * 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 __EHCI_H
+#define __EHCI_H
+
+#include <pci.h>
+#include <usb/usb.h>
+
+hci_t *ehci_init (pcidev_t addr);
+
+void ehci_rh_init (usbdev_t *dev);
+
+#endif
diff --git a/payloads/libpayload/drivers/usb/ehci_private.h b/payloads/libpayload/drivers/usb/ehci_private.h
new file mode 100644
index 0000000000..e63a81db13
--- /dev/null
+++ b/payloads/libpayload/drivers/usb/ehci_private.h
@@ -0,0 +1,266 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2010 coresystems GmbH
+ *
+ * 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 __EHCI_PRIVATE_H
+#define __EHCI_PRIVATE_H
+
+#include <pci.h>
+#include <usb/usb.h>
+
+#define USBBASE 0x10
+#define FLADJ 0x61
+#define FLADJ_framelength(x) (((x)-59488)/16)
+
+typedef union {
+	u32 val;
+	volatile struct {
+		unsigned long current_conn_status:1;
+		unsigned long conn_status_change:1;
+		unsigned long port_enable:1;
+		unsigned long port_enable_change:1;
+		unsigned long overcurrent:1;
+		unsigned long overcurrent_change:1;
+		unsigned long force_port_resume:1;
+		unsigned long suspend:1;
+		unsigned long port_reset:1;
+		unsigned long:1;
+		unsigned long line_status:2;
+		unsigned long pp:1;
+		unsigned long port_owner:1;
+		unsigned long port_indicator_control:2;
+		unsigned long port_test_control:4;
+		unsigned long wake_on_connect_en:1;
+		unsigned long wake_on_disconnect_en:1;
+		unsigned long wake_on_overcurrent_en:1;
+		unsigned long:9;
+	} __attribute__ ((packed));
+} __attribute__ ((packed)) portsc_t;
+
+typedef struct {
+	u8 caplength;
+	u8 res1;
+	u16 hciversion;
+	union {
+		u32 hcsparams;
+		struct {
+			unsigned long n_ports:4;
+			unsigned long ppc:1;
+			unsigned long:2;
+			unsigned long port_routing_rules:1;
+			unsigned long n_pcc:4;
+			unsigned long n_cc:4;
+			unsigned long p_indicator:1;
+			unsigned long:3;
+			unsigned long debug_port_number:4;
+			unsigned long:8;
+		} __attribute__ ((packed));
+	};
+	union {
+		u32 hccparams;
+		struct {
+			unsigned long cap_64b_addr:1;
+			unsigned long cap_prog_framelist_size:1;
+			unsigned long cap_async_park:1;
+			unsigned long:1;
+			unsigned long isoc_sched_threshold:4;
+			unsigned long eecp:8;
+			unsigned long:16;
+		} __attribute__ ((packed));
+	};
+	union {
+		u64 hcsp_portroute;
+		struct {
+			unsigned long portroute0:4;
+			unsigned long portroute1:4;
+			unsigned long portroute2:4;
+			unsigned long portroute3:4;
+			unsigned long portroute4:4;
+			unsigned long portroute5:4;
+			unsigned long portroute6:4;
+			unsigned long portroute7:4;
+			unsigned long portroute8:4;
+			unsigned long portroute9:4;
+			unsigned long portroute10:4;
+			unsigned long portroute11:4;
+			unsigned long portroute12:4;
+			unsigned long portroute13:4;
+			unsigned long portroute14:4;
+			unsigned long portroute15:4;
+			unsigned long:4;
+		} __attribute__ ((packed));
+	};
+} __attribute__ ((packed)) hc_cap_t;
+
+typedef struct {
+	union {
+		u32 usbcmd;
+		volatile struct {
+			unsigned long rs:1;
+			unsigned long hcreset:1;
+			unsigned long frame_list_size:2;
+			unsigned long periodic_sched_enable:1;
+			unsigned long async_sched_enable:1;
+			unsigned long irq_on_async_advance_doorbell:1;
+			unsigned long light_hc_reset:1;
+			unsigned long async_sched_park_mode_count:2;
+			unsigned long:1;
+			unsigned long async_sched_park_mode_enable:1;
+			unsigned long:4;
+			unsigned long irq_threshold_count:8;
+			unsigned long:8;
+		} __attribute__ ((packed));
+	};
+	union {
+		u32 usbsts;
+		struct {
+			unsigned long usbint:1;
+			unsigned long usberrint:1;
+			unsigned long port_change_detect:1;
+			unsigned long frame_list_rollover:1;
+			unsigned long host_system_error:1;
+			unsigned long irq_on_async_advance:1;
+			unsigned long:6;
+			unsigned long hchalted:1;
+			unsigned long reclamation:1;
+			unsigned long periodic_sched_status:1;
+			unsigned long async_sched_status:1;
+			unsigned long:16;
+		} __attribute__ ((packed));
+	};
+	union {
+		u32 usbintr;
+		struct {
+			unsigned long en_usb_irq:1;
+			unsigned long en_usb_err_irq:1;
+			unsigned long en_port_change_irq:1;
+			unsigned long en_frame_list_rollover_irq:1;
+			unsigned long en_host_system_error_irq:1;
+			unsigned long en_irq_on_async_advance:1;
+			unsigned long:26;
+		} __attribute__ ((packed));
+	};
+	u32 frindex;
+	u32 ctrldssegment;
+	u32 periodiclistbase;
+	u32 asynclistaddr;
+	u8 res1[0x3f-0x1c];
+	u32 configflag;
+	portsc_t portsc[0];
+} hc_op_t;
+
+typedef struct {
+	union {
+		u32 next_qtd;
+		struct {
+			unsigned long terminate:1;
+			unsigned long:4;
+			unsigned long:27;
+		} __attribute__ ((packed));
+	};
+	union {
+		u32 alt_next_qtd;
+		struct {
+			unsigned long alt_terminate:1;
+			unsigned long:4;
+			unsigned long:27;
+		} __attribute__ ((packed));
+	};
+	struct {
+		union {
+			volatile u8 status;
+			struct {
+				volatile unsigned long perr:1;
+				volatile unsigned long splitxstate:1;
+				volatile unsigned long missed_mframe:1;
+				volatile unsigned long xact_err:1;
+				volatile unsigned long babble:1;
+				volatile unsigned long data_buf_err:1;
+				volatile unsigned long halted:1;
+				volatile unsigned long active:1;
+			} __attribute__ ((packed));
+		};
+		unsigned long pid:2;
+		volatile unsigned long cerr:2;
+		volatile unsigned long c_page:3;
+		unsigned long ioc:1;
+		volatile unsigned long total_len:15;
+		volatile unsigned long dt:1;
+	} __attribute__ ((packed));
+	union {
+		u32 bufptr0;
+		struct {
+			volatile unsigned long cur_off:12;
+			unsigned long:20;
+		} __attribute__ ((packed));
+	};
+	u32 bufptrs[4];
+	u32 bufptrs64[5];
+} __attribute__ ((packed)) qtd_t;
+
+typedef struct {
+	union {
+		u32 horiz_link_ptr;
+		struct {
+			unsigned long terminate:1;
+			unsigned long type:2;
+			unsigned long:1;
+			unsigned long:28;
+		} __attribute__ ((packed));
+	};
+	struct {
+		unsigned long addr:7;
+		unsigned long inactivate:1;
+		unsigned long ep:4;
+		unsigned long eps:2;
+		unsigned long dtc:1;
+		unsigned long reclaim_head:1;
+		unsigned long max_packet_len:11;
+		unsigned long non_hs_control_ep:1;
+		unsigned long nak_cnt_reload:4;
+	} __attribute__ ((packed));
+	struct {
+		unsigned long irq_sched_mask:8;
+		unsigned long split_compl_mask:8;
+		unsigned long hub_addr:7;
+		unsigned long port_num:7;
+		unsigned long pipe_multiplier:2;
+	} __attribute__ ((packed));
+	volatile u32 current_td_ptr;
+	volatile qtd_t td;
+} ehci_qh_t;
+
+typedef struct ehci {
+	hc_cap_t *capabilities;
+	hc_op_t *operation;
+} ehci_t;
+
+
+#define EHCI_INST(controller) ((ehci_t*)((controller)->instance))
+
+#endif
diff --git a/payloads/libpayload/drivers/usb/ehci_rh.c b/payloads/libpayload/drivers/usb/ehci_rh.c
new file mode 100644
index 0000000000..5eaeeb690e
--- /dev/null
+++ b/payloads/libpayload/drivers/usb/ehci_rh.c
@@ -0,0 +1,145 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2010 coresystems GmbH
+ *
+ * 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.
+ */
+
+#include <libpayload.h>
+#include "ehci.h"
+#include "ehci_private.h"
+
+typedef struct {
+	int n_ports;
+	/* typical C, n_ports is the number
+	 * of ports, while ports[] spans [0,n_ports-1],
+	 * even though the spec counts from 1.
+	 */
+	volatile portsc_t *ports;
+	int *devices;
+} rh_inst_t;
+
+#define RH_INST(dev) ((rh_inst_t*)(dev)->data)
+
+static void
+ehci_rh_destroy (usbdev_t *dev)
+{
+        free (RH_INST(dev)->devices);
+        free (RH_INST(dev));
+}
+
+static void
+ehci_rh_hand_over_port (usbdev_t *dev, int port)
+{
+	volatile portsc_t *p = &(RH_INST(dev)->ports[port]);
+
+	printf("giving up port %x, it's USB1\n", port+1);
+
+	/* Lowspeed device. Hand over to companion */
+	p->port_owner = 1;
+	do {} while (!p->conn_status_change);
+	/* RW/C register, so clear it by writing 1 */
+	p->conn_status_change = 1;
+	return;
+}
+
+static void
+ehci_rh_scanport (usbdev_t *dev, int port)
+{
+	volatile portsc_t *p = &(RH_INST(dev)->ports[port]);
+	if (RH_INST(dev)->devices[port]!=-1) {
+		printf("Unregister device at port %x\n", port+1);
+		usb_detach_device(dev->controller, RH_INST(dev)->devices[port]);
+		RH_INST(dev)->devices[port]=-1;
+	}
+	/* device connected, handle */
+	if (p->current_conn_status) {
+		mdelay(100);
+		if (p->line_status == 0x1) {
+			ehci_rh_hand_over_port(dev, port);
+			return;
+		}
+		p->port_enable = 0;
+		p->port_reset = 1;
+		mdelay(50);
+		p->port_reset = 0;
+		/* Wait for flag change to finish. The controller might take a while */
+		while (p->port_reset) ;
+		if (!p->port_enable) {
+			ehci_rh_hand_over_port(dev, port);
+			return;
+		}
+		printf("port %x hosts a USB2 device\n", port+1);
+		RH_INST(dev)->devices[port] = usb_attach_device(dev->controller, dev->address, port, 2);
+	}
+	/* RW/C register, so clear it by writing 1 */
+	p->conn_status_change = 1;
+}
+
+static int
+ehci_rh_report_port_changes (usbdev_t *dev)
+{
+	int i;
+	for (i=0; i<RH_INST(dev)->n_ports; i++) {
+		if (RH_INST(dev)->ports[i].conn_status_change)
+			return i;
+	}
+	return -1;
+}
+
+static void
+ehci_rh_poll (usbdev_t *dev)
+{
+	int port;
+	while ((port = ehci_rh_report_port_changes (dev)) != -1)
+		ehci_rh_scanport (dev, port);
+}
+
+
+void
+ehci_rh_init (usbdev_t *dev)
+{
+	int i;
+
+	dev->destroy = ehci_rh_destroy;
+	dev->poll = ehci_rh_poll;
+
+	dev->data = malloc(sizeof(rh_inst_t));
+
+	RH_INST(dev)->n_ports = EHCI_INST(dev->controller)->capabilities->n_ports;
+	RH_INST(dev)->ports = EHCI_INST(dev->controller)->operation->portsc;
+
+	printf("root hub has %x ports\n", RH_INST(dev)->n_ports);
+
+	RH_INST(dev)->devices = malloc(RH_INST(dev)->n_ports * sizeof(int));
+	for (i=0; i < RH_INST(dev)->n_ports; i++) {
+		RH_INST(dev)->devices[i] = -1;
+		RH_INST(dev)->ports[i].pp = 1;
+	}
+
+	dev->address = 0;
+	dev->hub = -1;
+	dev->port = -1;
+}
diff --git a/payloads/libpayload/drivers/usb/usbinit.c b/payloads/libpayload/drivers/usb/usbinit.c
index 50dbf97470..f0d5a60d1e 100644
--- a/payloads/libpayload/drivers/usb/usbinit.c
+++ b/payloads/libpayload/drivers/usb/usbinit.c
@@ -31,7 +31,7 @@
 #include <usb/usb.h>
 #include "uhci.h"
 #include "ohci.h"
-//#include "ehci.h"
+#include "ehci.h"
 #include "xhci.h"
 #include <usb/usbdisk.h>
 
@@ -90,8 +90,7 @@ usb_controller_initialize (int bus, int dev, int func)
 		if (prog_if == 0x20) {
 			printf ("EHCI controller\n");
 #ifdef CONFIG_USB_EHCI
-			//ehci_init(addr);
-			printf ("Not supported.\n");
+			ehci_init(addr);
 #else
 			printf ("Not supported.\n");
 #endif