Merge https://source.denx.de/u-boot/custodians/u-boot-usbWIP/26Jan2022

9 files changed, 962 insertions, 70 deletions

diff --git a/common/stdio.c b/common/stdio.c
index 976f51c..063c659 100644
--- a/common/stdio.c
+++ b/common/stdio.c
@@ -381,6 +381,9 @@ int stdio_add_devices(void)
 #ifdef CONFIG_USB_TTY
 	drv_usbtty_init();
 #endif
+#ifdef CONFIG_USB_FUNCTION_ACM
+	drv_usbacm_init ();
+#endif
 	if (IS_ENABLED(CONFIG_NETCONSOLE))
 		drv_nc_init();
 #ifdef CONFIG_JTAG_CONSOLE
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 327ea86..d81a9c5 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -182,6 +182,15 @@ config USB_FUNCTION_THOR
 	  Enable Tizen's THOR download protocol support in U-Boot. It
 	  allows downloading images into memory and flash them to target device.
 
+config USB_FUNCTION_ACM
+	bool "Enable CDC ACM gadget"
+	select SYS_STDIO_DEREGISTER
+	select CIRCBUF
+	help
+	  ACM serial link. This function can be used to create a stdio device to
+	  interoperate with MS-Windows hosts or with the Linux-USB "cdc-acm"
+	  driver.
+
 endif # USB_GADGET_DOWNLOAD
 
 config USB_ETHER
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index f560068..d5d891b 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_USB_FUNCTION_MASS_STORAGE) += f_mass_storage.o
 obj-$(CONFIG_USB_FUNCTION_FASTBOOT) += f_fastboot.o
 obj-$(CONFIG_USB_FUNCTION_SDP) += f_sdp.o
 obj-$(CONFIG_USB_FUNCTION_ROCKUSB) += f_rockusb.o
+obj-$(CONFIG_USB_FUNCTION_ACM)	+= f_acm.o
 endif
 endif
 ifdef CONFIG_USB_ETHER
diff --git a/drivers/usb/gadget/f_acm.c b/drivers/usb/gadget/f_acm.c
new file mode 100644
index 0000000..388f73d
--- /dev/null
+++ b/drivers/usb/gadget/f_acm.c
@@ -0,0 +1,672 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * USB CDC serial (ACM) function driver
+ *
+ * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
+ * Copyright (C) 2008 by David Brownell
+ * Copyright (C) 2008 by Nokia Corporation
+ * Copyright (C) 2009 by Samsung Electronics
+ * Copyright (c) 2021, Linaro Ltd <loic.poulain@linaro.org>
+ */
+
+#include <circbuf.h>
+#include <common.h>
+#include <console.h>
+#include <errno.h>
+#include <g_dnl.h>
+#include <malloc.h>
+#include <memalign.h>
+#include <stdio_dev.h>
+#include <version.h>
+#include <watchdog.h>
+
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/composite.h>
+#include <linux/usb/cdc.h>
+
+#define REQ_SIZE_MAX	512
+
+struct f_acm {
+	int ctrl_id;
+	int data_id;
+
+	struct usb_ep *ep_in;
+	struct usb_ep *ep_out;
+	struct usb_ep *ep_notify;
+
+	struct usb_request *req_in;
+	struct usb_request *req_out;
+
+	bool connected;
+	bool tx_on;
+
+	circbuf_t rx_buf;
+	circbuf_t tx_buf;
+
+	struct usb_function usb_function;
+
+	struct usb_cdc_line_coding line_coding;
+	u16 handshake_bits;
+#define ACM_CTRL_RTS	BIT(1)	/* unused with full duplex */
+#define ACM_CTRL_DTR	BIT(0)	/* host is ready for data r/w */
+
+	int controller_index;
+};
+
+static struct f_acm *default_acm_function;
+
+static inline struct f_acm *func_to_acm(struct usb_function *f)
+{
+	return container_of(f, struct f_acm, usb_function);
+}
+
+static inline struct f_acm *stdio_to_acm(struct stdio_dev *s)
+{
+	/* stdio dev is cloned on registration, do not use container_of */
+	return s->priv;
+}
+
+static struct usb_interface_assoc_descriptor
+acm_iad_descriptor = {
+	.bLength =              sizeof(acm_iad_descriptor),
+	.bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
+	.bFirstInterface =      0,
+	.bInterfaceCount =      2,	// control + data
+	.bFunctionClass =       USB_CLASS_COMM,
+	.bFunctionSubClass =    USB_CDC_SUBCLASS_ACM,
+	.bFunctionProtocol =    USB_CDC_ACM_PROTO_AT_V25TER,
+};
+
+static struct usb_interface_descriptor acm_control_intf_desc = {
+	.bLength =              USB_DT_INTERFACE_SIZE,
+	.bDescriptorType =      USB_DT_INTERFACE,
+	.bNumEndpoints =        1,
+	.bInterfaceClass =      USB_CLASS_COMM,
+	.bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
+	.bInterfaceProtocol =   USB_CDC_ACM_PROTO_AT_V25TER,
+};
+
+static struct usb_interface_descriptor acm_data_intf_desc = {
+	.bLength =              sizeof(acm_data_intf_desc),
+	.bDescriptorType =      USB_DT_INTERFACE,
+	.bNumEndpoints =        2,
+	.bInterfaceClass =      USB_CLASS_CDC_DATA,
+};
+
+static struct usb_cdc_header_desc acm_header_desc = {
+	.bLength =		sizeof(acm_header_desc),
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
+	.bcdCDC =		__constant_cpu_to_le16(0x0110),
+};
+
+static struct usb_cdc_call_mgmt_descriptor acm_call_mgmt_desc = {
+	.bLength =              sizeof(acm_call_mgmt_desc),
+	.bDescriptorType =      USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
+	.bmCapabilities =       0,
+	.bDataInterface =       0x01,
+};
+
+static struct usb_cdc_acm_descriptor acm_desc = {
+	.bLength =		sizeof(acm_desc),
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_ACM_TYPE,
+	.bmCapabilities =	USB_CDC_CAP_LINE,
+};
+
+static struct usb_cdc_union_desc acm_union_desc = {
+	.bLength =		sizeof(acm_union_desc),
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
+	.bMasterInterface0 =	0x00,
+	.bSlaveInterface0 =	0x01,
+};
+
+static struct usb_endpoint_descriptor acm_fs_notify_desc = {
+	.bLength =              USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =      USB_DT_ENDPOINT,
+	.bEndpointAddress =     3 | USB_DIR_IN,
+	.bmAttributes =         USB_ENDPOINT_XFER_INT,
+	.wMaxPacketSize =       __constant_cpu_to_le16(64),
+	.bInterval =            32,
+};
+
+static struct usb_endpoint_descriptor acm_fs_in_desc = {
+	.bLength =              USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =      USB_DT_ENDPOINT,
+	.bEndpointAddress =     USB_DIR_IN,
+	.bmAttributes =         USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor acm_fs_out_desc = {
+	.bLength =              USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =      USB_DT_ENDPOINT,
+	.bEndpointAddress =     USB_DIR_OUT,
+	.bmAttributes =         USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *acm_fs_function[] = {
+	(struct usb_descriptor_header *)&acm_iad_descriptor,
+	(struct usb_descriptor_header *)&acm_control_intf_desc,
+	(struct usb_descriptor_header *)&acm_header_desc,
+	(struct usb_descriptor_header *)&acm_call_mgmt_desc,
+	(struct usb_descriptor_header *)&acm_desc,
+	(struct usb_descriptor_header *)&acm_union_desc,
+	(struct usb_descriptor_header *)&acm_fs_notify_desc,
+	(struct usb_descriptor_header *)&acm_data_intf_desc,
+	(struct usb_descriptor_header *)&acm_fs_in_desc,
+	(struct usb_descriptor_header *)&acm_fs_out_desc,
+	NULL,
+};
+
+static struct usb_endpoint_descriptor acm_hs_notify_desc = {
+	.bLength =              USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =      USB_DT_ENDPOINT,
+	.bmAttributes =         USB_ENDPOINT_XFER_INT,
+	.wMaxPacketSize =       __constant_cpu_to_le16(64),
+	.bInterval =            11,
+};
+
+static struct usb_endpoint_descriptor acm_hs_in_desc = {
+	.bLength		= USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType	= USB_DT_ENDPOINT,
+	.bmAttributes		= USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize		= __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor acm_hs_out_desc = {
+	.bLength		= USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType	= USB_DT_ENDPOINT,
+	.bmAttributes		= USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize		= __constant_cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *acm_hs_function[] = {
+	(struct usb_descriptor_header *)&acm_iad_descriptor,
+	(struct usb_descriptor_header *)&acm_control_intf_desc,
+	(struct usb_descriptor_header *)&acm_header_desc,
+	(struct usb_descriptor_header *)&acm_call_mgmt_desc,
+	(struct usb_descriptor_header *)&acm_desc,
+	(struct usb_descriptor_header *)&acm_union_desc,
+	(struct usb_descriptor_header *)&acm_hs_notify_desc,
+	(struct usb_descriptor_header *)&acm_data_intf_desc,
+	(struct usb_descriptor_header *)&acm_hs_in_desc,
+	(struct usb_descriptor_header *)&acm_hs_out_desc,
+	NULL,
+};
+
+static inline struct usb_endpoint_descriptor *
+ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *hs,
+	struct usb_endpoint_descriptor *fs)
+{
+	if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
+		return hs;
+	return fs;
+}
+
+static int acm_bind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct usb_gadget *gadget = c->cdev->gadget;
+	struct f_acm *f_acm = func_to_acm(f);
+	struct usb_ep *ep;
+	int id;
+
+	id = usb_interface_id(c, f);
+	if (id < 0)
+		return id;
+
+	acm_iad_descriptor.bFirstInterface = id;
+	acm_control_intf_desc.bInterfaceNumber = id;
+	acm_union_desc.bMasterInterface0 = id;
+
+	f_acm->ctrl_id = id;
+
+	id = usb_interface_id(c, f);
+	if (id < 0)
+		return id;
+
+	acm_data_intf_desc.bInterfaceNumber = id;
+	acm_union_desc.bSlaveInterface0 = id;
+	acm_call_mgmt_desc.bDataInterface = id;
+
+	f_acm->data_id = id;
+
+	/* allocate instance-specific endpoints */
+	ep = usb_ep_autoconfig(gadget, &acm_fs_in_desc);
+	if (!ep)
+		return -ENODEV;
+
+	f_acm->ep_in = ep;
+
+	ep = usb_ep_autoconfig(gadget, &acm_fs_out_desc);
+	if (!ep)
+		return -ENODEV;
+
+	f_acm->ep_out = ep;
+
+	ep = usb_ep_autoconfig(gadget, &acm_fs_notify_desc);
+	if (!ep)
+		return -ENODEV;
+
+	f_acm->ep_notify = ep;
+
+	if (gadget_is_dualspeed(gadget)) {
+		/* Assume endpoint addresses are the same for both speeds */
+		acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
+		acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
+		acm_hs_notify_desc.bEndpointAddress = acm_fs_notify_desc.bEndpointAddress;
+	}
+
+	return 0;
+}
+
+static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct f_acm *f_acm = func_to_acm(f);
+
+	if (default_acm_function == f_acm)
+		default_acm_function = NULL;
+
+	buf_free(&f_acm->rx_buf);
+	buf_free(&f_acm->tx_buf);
+
+	free(f_acm);
+}
+
+static void acm_notify_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	/* nothing to do */
+}
+
+static void acm_tx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_acm *f_acm = req->context;
+
+	f_acm->tx_on = true;
+}
+
+static void acm_rx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_acm *f_acm = req->context;
+
+	buf_push(&f_acm->rx_buf, req->buf, req->actual);
+
+	/* Queue RX req again */
+	req->actual = 0;
+	usb_ep_queue(ep, req, 0);
+}
+
+static struct usb_request *acm_start_ep(struct usb_ep *ep, void *complete_cb,
+					void *context)
+{
+	struct usb_request *req;
+
+	req = usb_ep_alloc_request(ep, 0);
+	if (!req)
+		return NULL;
+
+	req->length = REQ_SIZE_MAX;
+	req->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, REQ_SIZE_MAX);
+	if (!req->buf) {
+		usb_ep_free_request(ep, req);
+		return NULL;
+	}
+
+	memset(req->buf, 0, req->length);
+	req->complete = complete_cb;
+	req->context = context;
+
+	return req;
+}
+
+static int acm_start_data(struct f_acm *f_acm, struct usb_gadget *gadget)
+{
+	const struct usb_endpoint_descriptor *d;
+	int ret;
+
+	/* EP IN */
+	d = ep_desc(gadget, &acm_hs_in_desc, &acm_fs_in_desc);
+	ret = usb_ep_enable(f_acm->ep_in, d);
+	if (ret)
+		return ret;
+
+	f_acm->req_in = acm_start_ep(f_acm->ep_in, acm_tx_complete, f_acm);
+
+	/* EP OUT */
+	d = ep_desc(gadget, &acm_hs_out_desc, &acm_fs_out_desc);
+	ret = usb_ep_enable(f_acm->ep_out, d);
+	if (ret)
+		return ret;
+
+	f_acm->req_out = acm_start_ep(f_acm->ep_out, acm_rx_complete, f_acm);
+
+	/* Start OUT transfer (EP OUT) */
+	ret = usb_ep_queue(f_acm->ep_out, f_acm->req_out, 0);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int acm_start_ctrl(struct f_acm *f_acm, struct usb_gadget *gadget)
+{
+	const struct usb_endpoint_descriptor *d;
+
+	usb_ep_disable(f_acm->ep_notify);
+
+	d = ep_desc(gadget, &acm_hs_notify_desc, &acm_fs_notify_desc);
+	usb_ep_enable(f_acm->ep_notify, d);
+
+	acm_start_ep(f_acm->ep_notify, acm_notify_complete, f_acm);
+
+	return 0;
+}
+
+static int acm_set_alt(struct usb_function *f, unsigned int intf, unsigned int alt)
+{
+	struct usb_gadget *gadget = f->config->cdev->gadget;
+	struct f_acm *f_acm = func_to_acm(f);
+
+	if (intf == f_acm->ctrl_id) {
+		return acm_start_ctrl(f_acm, gadget);
+	} else if (intf == f_acm->data_id) {
+		acm_start_data(f_acm, gadget);
+		f_acm->connected = true;
+		f_acm->tx_on = true;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
+{
+	struct usb_gadget *gadget =  f->config->cdev->gadget;
+	struct usb_request *req = f->config->cdev->req;
+	u16 w_index = le16_to_cpu(ctrl->wIndex);
+	u16 w_value = le16_to_cpu(ctrl->wValue);
+	u16 w_length = le16_to_cpu(ctrl->wLength);
+	struct f_acm *f_acm = func_to_acm(f);
+	int value = -1;
+
+	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+			| USB_CDC_REQ_SET_LINE_CODING:
+		/* SET_LINE_CODING */
+
+		if (w_length != sizeof(f_acm->line_coding) || w_index != f_acm->ctrl_id)
+			goto invalid;
+
+		value = w_length;
+
+		memcpy(&f_acm->line_coding, req->buf, value);
+
+		break;
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+			| USB_CDC_REQ_GET_LINE_CODING:
+		/* GET_LINE_CODING */
+
+		if (w_length != sizeof(f_acm->line_coding) || w_index != f_acm->ctrl_id)
+			goto invalid;
+
+		value = w_length;
+
+		memcpy(req->buf, &f_acm->line_coding, value);
+
+		break;
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+			| USB_CDC_REQ_SET_CONTROL_LINE_STATE:
+		/* SET_CONTROL_LINE_STATE */
+
+		if (w_index != f_acm->ctrl_id)
+			goto invalid;
+
+		value = 0;
+
+		f_acm->handshake_bits = w_value;
+
+		break;
+	default:
+invalid:
+		printf("invalid control req%02x.%02x v%04x i%04x l%d\n",
+		       ctrl->bRequestType, ctrl->bRequest, w_value, w_index,
+		       w_length);
+	}
+
+	/* respond with data transfer or status phase? */
+	if (value >= 0) {
+		req->zero = 0;
+		req->length = value;
+		usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
+	}
+
+	return 0;
+}
+
+static void acm_disable(struct usb_function *f)
+{
+	struct f_acm *f_acm = func_to_acm(f);
+
+	usb_ep_disable(f_acm->ep_out);
+	usb_ep_disable(f_acm->ep_in);
+	usb_ep_disable(f_acm->ep_notify);
+
+	if (f_acm->req_out) {
+		free(f_acm->req_out->buf);
+		usb_ep_free_request(f_acm->ep_out, f_acm->req_out);
+		f_acm->req_out = NULL;
+	}
+
+	if (f_acm->req_in) {
+		free(f_acm->req_in->buf);
+		usb_ep_free_request(f_acm->ep_in, f_acm->req_in);
+		f_acm->req_in = NULL;
+	}
+}
+
+/* static strings, in UTF-8 */
+static struct usb_string acm_string_defs[] = {
+	[0].s = "CDC Abstract Control Model (ACM)",
+	[1].s = "CDC ACM Data",
+	[2].s = "CDC Serial",
+	{  } /* end of list */
+};
+
+static struct usb_gadget_strings acm_string_table = {
+	.language = 0x0409, /* en-us */
+	.strings = acm_string_defs,
+};
+
+static struct usb_gadget_strings *acm_strings[] = {
+	&acm_string_table,
+	NULL,
+};
+
+static void __acm_tx(struct f_acm *f_acm)
+{
+	int len, ret;
+
+	do {
+		usb_gadget_handle_interrupts(f_acm->controller_index);
+
+		if (!(f_acm->handshake_bits & ACM_CTRL_DTR))
+			break;
+
+		if (!f_acm->tx_on)
+			continue;
+
+		len = buf_pop(&f_acm->tx_buf, f_acm->req_in->buf, REQ_SIZE_MAX);
+		if (!len)
+			break;
+
+		f_acm->req_in->length = len;
+
+		ret = usb_ep_queue(f_acm->ep_in, f_acm->req_in, 0);
+		if (ret)
+			break;
+
+		f_acm->tx_on = false;
+
+		/* Do not reset the watchdog, if TX is stuck there is probably
+		 * a real issue.
+		 */
+	} while (1);
+}
+
+static bool acm_connected(struct stdio_dev *dev)
+{
+	struct f_acm *f_acm = stdio_to_acm(dev);
+
+	/* give a chance to process udc irq */
+	usb_gadget_handle_interrupts(f_acm->controller_index);
+
+	return f_acm->connected;
+}
+
+static int acm_add(struct usb_configuration *c)
+{
+	struct f_acm *f_acm;
+	int status;
+
+	f_acm = calloc(1, sizeof(*f_acm));
+	if (!f_acm)
+		return -ENOMEM;
+
+	f_acm->usb_function.name = "f_acm";
+	f_acm->usb_function.bind = acm_bind;
+	f_acm->usb_function.unbind = acm_unbind;
+	f_acm->usb_function.set_alt = acm_set_alt;
+	f_acm->usb_function.disable = acm_disable;
+	f_acm->usb_function.strings = acm_strings;
+	f_acm->usb_function.descriptors = acm_fs_function;
+	f_acm->usb_function.hs_descriptors = acm_hs_function;
+	f_acm->usb_function.setup = acm_setup;
+	f_acm->controller_index = 0;
+
+	status = usb_add_function(c, &f_acm->usb_function);
+	if (status) {
+		free(f_acm);
+		return status;
+	}
+
+	buf_init(&f_acm->rx_buf, 2048);
+	buf_init(&f_acm->tx_buf, 2048);
+
+	if (!default_acm_function)
+		default_acm_function = f_acm;
+
+	return status;
+}
+
+DECLARE_GADGET_BIND_CALLBACK(usb_serial_acm, acm_add);
+
+/* STDIO */
+static int acm_stdio_tstc(struct stdio_dev *dev)
+{
+	struct f_acm *f_acm = stdio_to_acm(dev);
+
+	usb_gadget_handle_interrupts(f_acm->controller_index);
+
+	return (f_acm->rx_buf.size > 0);
+}
+
+static int acm_stdio_getc(struct stdio_dev *dev)
+{
+	struct f_acm *f_acm = stdio_to_acm(dev);
+	char c;
+
+	/* Wait for a character to arrive. */
+	while (!acm_stdio_tstc(dev))
+		WATCHDOG_RESET();
+
+	buf_pop(&f_acm->rx_buf, &c, 1);
+
+	return c;
+}
+
+static void acm_stdio_putc(struct stdio_dev *dev, const char c)
+{
+	struct f_acm *f_acm = stdio_to_acm(dev);
+
+	if (c == '\n')
+		buf_push(&f_acm->tx_buf, "\r", 1);
+
+	buf_push(&f_acm->tx_buf, &c, 1);
+
+	if (!f_acm->connected)
+		return;
+
+	__acm_tx(f_acm);
+}
+
+static void acm_stdio_puts(struct stdio_dev *dev, const char *str)
+{
+	struct f_acm *f_acm = stdio_to_acm(dev);
+
+	while (*str) {
+		if (*str == '\n')
+			buf_push(&f_acm->tx_buf, "\r", 1);
+
+		buf_push(&f_acm->tx_buf, str++, 1);
+	}
+
+	if (!f_acm->connected)
+		return;
+
+	__acm_tx(f_acm);
+}
+
+static int acm_stdio_start(struct stdio_dev *dev)
+{
+	int ret;
+
+	if (dev->priv) { /* function already exist */
+		return 0;
+	}
+
+	ret = g_dnl_register("usb_serial_acm");
+	if (ret)
+		return ret;
+
+	if (default_acm_function)
+		dev->priv = default_acm_function;
+	else
+		return -ENODEV;
+
+	while (!acm_connected(dev)) {
+		if (ctrlc())
+			return -ECANCELED;
+
+		WATCHDOG_RESET();
+	}
+
+	return 0;
+}
+
+static int acm_stdio_stop(struct stdio_dev *dev)
+{
+	g_dnl_unregister();
+	g_dnl_clear_detach();
+
+	return 0;
+}
+
+int drv_usbacm_init(void)
+{
+	struct stdio_dev stdio;
+
+	strcpy(stdio.name, "usbacm");
+	stdio.flags = DEV_FLAGS_INPUT | DEV_FLAGS_OUTPUT;
+	stdio.tstc = acm_stdio_tstc;
+	stdio.getc = acm_stdio_getc;
+	stdio.putc = acm_stdio_putc;
+	stdio.puts = acm_stdio_puts;
+	stdio.start = acm_stdio_start;
+	stdio.stop = acm_stdio_stop;
+	stdio.priv = NULL;
+	stdio.ext = 0;
+
+	return stdio_register(&stdio);
+}
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index ccecb5a..7743c96 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -180,12 +180,13 @@ config USB_EHCI_MX7
 	  Enables support for the on-chip EHCI controller on i.MX7 SoCs.
 
 config USB_EHCI_MXS
-	bool "Support for i.MX23 EHCI USB controller"
-	depends on ARCH_MX23
+	bool "Support for i.MX23/i.MX28 EHCI USB controller"
+	depends on ARCH_MX23 || ARCH_MX28
 	default y
 	select USB_EHCI_IS_TDI
 	help
-	  Enables support for the on-chip EHCI controller on i.MX23 SoCs.
+	  Enables support for the on-chip EHCI controller on i.MX23 and
+	  i.MX28 SoCs.
 
 config USB_EHCI_OMAP
 	bool "Support for OMAP3+ on-chip EHCI USB controller"
diff --git a/drivers/usb/host/ehci-mxs.c b/drivers/usb/host/ehci-mxs.c
index 824c620..9a61495 100644
--- a/drivers/usb/host/ehci-mxs.c
+++ b/drivers/usb/host/ehci-mxs.c
@@ -11,6 +11,8 @@
 #include <asm/arch/imx-regs.h>
 #include <errno.h>
 #include <linux/delay.h>
+#include <dm.h>
+#include <power/regulator.h>
 
 #include "ehci.h"
 
@@ -29,6 +31,88 @@ struct ehci_mxs_port {
 	uint32_t		gate_bits;
 };
 
+static int ehci_mxs_toggle_clock(const struct ehci_mxs_port *port, int enable)
+{
+	struct mxs_register_32 *digctl_ctrl =
+		(struct mxs_register_32 *)HW_DIGCTL_CTRL;
+	int pll_offset, dig_offset;
+
+	if (enable) {
+		pll_offset = offsetof(struct mxs_register_32, reg_set);
+		dig_offset = offsetof(struct mxs_register_32, reg_clr);
+		writel(port->gate_bits, (u32)&digctl_ctrl->reg + dig_offset);
+		writel(port->pll_en_bits, (u32)port->pll + pll_offset);
+	} else {
+		pll_offset = offsetof(struct mxs_register_32, reg_clr);
+		dig_offset = offsetof(struct mxs_register_32, reg_set);
+		writel(port->pll_dis_bits, (u32)port->pll + pll_offset);
+		writel(port->gate_bits, (u32)&digctl_ctrl->reg + dig_offset);
+	}
+
+	return 0;
+}
+
+static int __ehci_hcd_init(struct ehci_mxs_port *port, enum usb_init_type init,
+			   struct ehci_hccr **hccr, struct ehci_hcor **hcor)
+{
+	u32 usb_base, cap_base;
+	int ret;
+
+	/* Reset the PHY block */
+	writel(USBPHY_CTRL_SFTRST, &port->phy_regs->hw_usbphy_ctrl_set);
+	udelay(10);
+	writel(USBPHY_CTRL_SFTRST | USBPHY_CTRL_CLKGATE,
+	       &port->phy_regs->hw_usbphy_ctrl_clr);
+
+	/* Enable USB clock */
+	ret = ehci_mxs_toggle_clock(port, 1);
+	if (ret)
+		return ret;
+
+	/* Start USB PHY */
+	writel(0, &port->phy_regs->hw_usbphy_pwd);
+
+	/* Enable UTMI+ Level 2 and Level 3 compatibility */
+	writel(USBPHY_CTRL_ENUTMILEVEL3 | USBPHY_CTRL_ENUTMILEVEL2 | 1,
+	       &port->phy_regs->hw_usbphy_ctrl_set);
+
+	usb_base = port->usb_regs + 0x100;
+	*hccr = (struct ehci_hccr *)usb_base;
+
+	cap_base = ehci_readl(&(*hccr)->cr_capbase);
+	*hcor = (struct ehci_hcor *)(usb_base + HC_LENGTH(cap_base));
+
+	return 0;
+}
+
+static int __ehci_hcd_stop(struct ehci_mxs_port *port)
+{
+	u32 usb_base, cap_base, tmp;
+	struct ehci_hccr *hccr;
+	struct ehci_hcor *hcor;
+
+	/* Stop the USB port */
+	usb_base = port->usb_regs + 0x100;
+	hccr = (struct ehci_hccr *)usb_base;
+	cap_base = ehci_readl(&hccr->cr_capbase);
+	hcor = (struct ehci_hcor *)(usb_base + HC_LENGTH(cap_base));
+
+	tmp = ehci_readl(&hcor->or_usbcmd);
+	tmp &= ~CMD_RUN;
+	ehci_writel(&hcor->or_usbcmd, tmp);
+
+	/* Disable the PHY */
+	tmp = USBPHY_PWD_RXPWDRX | USBPHY_PWD_RXPWDDIFF |
+		USBPHY_PWD_RXPWD1PT1 | USBPHY_PWD_RXPWDENV |
+		USBPHY_PWD_TXPWDV2I | USBPHY_PWD_TXPWDIBIAS |
+		USBPHY_PWD_TXPWDFS;
+	writel(tmp, &port->phy_regs->hw_usbphy_pwd);
+
+	/* Disable USB clock */
+	return ehci_mxs_toggle_clock(port, 0);
+}
+
+#if !CONFIG_IS_ENABLED(DM_USB)
 static const struct ehci_mxs_port mxs_port[] = {
 #ifdef CONFIG_EHCI_MXS_PORT0
 	{
@@ -56,27 +140,6 @@ static const struct ehci_mxs_port mxs_port[] = {
 #endif
 };
 
-static int ehci_mxs_toggle_clock(const struct ehci_mxs_port *port, int enable)
-{
-	struct mxs_register_32 *digctl_ctrl =
-		(struct mxs_register_32 *)HW_DIGCTL_CTRL;
-	int pll_offset, dig_offset;
-
-	if (enable) {
-		pll_offset = offsetof(struct mxs_register_32, reg_set);
-		dig_offset = offsetof(struct mxs_register_32, reg_clr);
-		writel(port->gate_bits, (u32)&digctl_ctrl->reg + dig_offset);
-		writel(port->pll_en_bits, (u32)port->pll + pll_offset);
-	} else {
-		pll_offset = offsetof(struct mxs_register_32, reg_clr);
-		dig_offset = offsetof(struct mxs_register_32, reg_set);
-		writel(port->pll_dis_bits, (u32)port->pll + pll_offset);
-		writel(port->gate_bits, (u32)&digctl_ctrl->reg + dig_offset);
-	}
-
-	return 0;
-}
-
 int __weak board_ehci_hcd_init(int port)
 {
 	return 0;
@@ -92,7 +155,6 @@ int ehci_hcd_init(int index, enum usb_init_type init,
 {
 
 	int ret;
-	uint32_t usb_base, cap_base;
 	const struct ehci_mxs_port *port;
 
 	if ((index < 0) || (index >= ARRAY_SIZE(mxs_port))) {
@@ -105,70 +167,204 @@ int ehci_hcd_init(int index, enum usb_init_type init,
 		return ret;
 
 	port = &mxs_port[index];
+	return __ehci_hcd_init(port, init, hccr, hcor);
+}
 
-	/* Reset the PHY block */
-	writel(USBPHY_CTRL_SFTRST, &port->phy_regs->hw_usbphy_ctrl_set);
-	udelay(10);
-	writel(USBPHY_CTRL_SFTRST | USBPHY_CTRL_CLKGATE,
-		&port->phy_regs->hw_usbphy_ctrl_clr);
+int ehci_hcd_stop(int index)
+{
+	int ret;
+	const struct ehci_mxs_port *port;
 
-	/* Enable USB clock */
-	ret = ehci_mxs_toggle_clock(port, 1);
+	if ((index < 0) || (index >= ARRAY_SIZE(mxs_port))) {
+		printf("Invalid port index (index = %d)!\n", index);
+		return -EINVAL;
+	}
+
+	port = &mxs_port[index];
+
+	ret = __ehci_hcd_stop(port);
+	board_ehci_hcd_exit(index);
+
+	return ret;
+}
+#else /* CONFIG_IS_ENABLED(DM_USB) */
+struct ehci_mxs_priv_data {
+	struct ehci_ctrl ctrl;
+	struct usb_ehci *ehci;
+	struct udevice *vbus_supply;
+	struct ehci_mxs_port port;
+	enum usb_init_type init_type;
+};
+
+/*
+ * Below defines correspond to imx28 clk Linux (v5.15.y)
+ * clock driver to provide proper offset for PHY[01]
+ * devices.
+ */
+#define CLK_USB_PHY0 62
+#define CLK_USB_PHY1 63
+#define PLL0CTRL0(base) ((base) + 0x0000)
+#define PLL1CTRL0(base) ((base) + 0x0020)
+
+static int ehci_usb_ofdata_to_platdata(struct udevice *dev)
+{
+	struct ehci_mxs_priv_data *priv = dev_get_priv(dev);
+	struct usb_plat *plat = dev_get_plat(dev);
+	struct ehci_mxs_port *port = &priv->port;
+	u32 phandle, phy_reg, clk_reg, clk_id;
+	ofnode phy_node, clk_node;
+	const char *mode;
+	int ret;
+
+	mode = ofnode_read_string(dev->node_, "dr_mode");
+	if (mode) {
+		if (strcmp(mode, "peripheral") == 0)
+			plat->init_type = USB_INIT_DEVICE;
+		else if (strcmp(mode, "host") == 0)
+			plat->init_type = USB_INIT_HOST;
+		else
+			return -EINVAL;
+	}
+
+	/* Read base address of the USB IP block */
+	ret = ofnode_read_u32(dev->node_, "reg", &port->usb_regs);
 	if (ret)
 		return ret;
 
-	/* Start USB PHY */
-	writel(0, &port->phy_regs->hw_usbphy_pwd);
+	/* Read base address of the USB PHY IP block */
+	ret = ofnode_read_u32(dev->node_, "fsl,usbphy", &phandle);
+	if (ret)
+		return ret;
 
-	/* Enable UTMI+ Level 2 and Level 3 compatibility */
-	writel(USBPHY_CTRL_ENUTMILEVEL3 | USBPHY_CTRL_ENUTMILEVEL2 | 1,
-		&port->phy_regs->hw_usbphy_ctrl_set);
+	phy_node = ofnode_get_by_phandle(phandle);
+	if (!ofnode_valid(phy_node))
+		return -ENODEV;
 
-	usb_base = port->usb_regs + 0x100;
-	*hccr = (struct ehci_hccr *)usb_base;
+	ret = ofnode_read_u32(phy_node, "reg", &phy_reg);
+	if (ret)
+		return ret;
 
-	cap_base = ehci_readl(&(*hccr)->cr_capbase);
-	*hcor = (struct ehci_hcor *)(usb_base + HC_LENGTH(cap_base));
+	port->phy_regs = (struct mxs_usbphy_regs *)phy_reg;
+
+	/* Read base address of the CLK IP block and proper ID */
+	ret = ofnode_read_u32_index(phy_node, "clocks", 0, &phandle);
+	if (ret)
+		return ret;
+
+	ret = ofnode_read_u32_index(phy_node, "clocks", 1, &clk_id);
+	if (ret)
+		return ret;
+
+	clk_node = ofnode_get_by_phandle(phandle);
+	if (!ofnode_valid(clk_node))
+		return -ENODEV;
+
+	ret = ofnode_read_u32(clk_node, "reg", &clk_reg);
+	if (ret)
+		return ret;
+
+	port->pll = (struct mxs_register_32 *)clk_reg;
+
+	/* Provide proper offset for USB PHY clocks */
+	if (clk_id == CLK_USB_PHY0)
+		port->pll = PLL0CTRL0(port->pll);
+
+	if (clk_id == CLK_USB_PHY1)
+		port->pll = PLL1CTRL0(port->pll);
+
+	debug("%s: pll_reg: 0x%p clk_id: %d\n", __func__, port->pll, clk_id);
+	/*
+	 * On the imx28 the values provided by CLKCTRL_PLL0* defines to are the
+	 * same as ones for CLKCTRL_PLL1*. As a result the former can be used
+	 * for both ports - i.e. (usb[01]).
+	 */
+	port->pll_en_bits = CLKCTRL_PLL0CTRL0_EN_USB_CLKS |
+		CLKCTRL_PLL0CTRL0_POWER;
+	port->pll_dis_bits = CLKCTRL_PLL0CTRL0_EN_USB_CLKS;
+	port->gate_bits = HW_DIGCTL_CTRL_USB0_CLKGATE;
 
 	return 0;
 }
 
-int ehci_hcd_stop(int index)
+static int ehci_usb_probe(struct udevice *dev)
 {
-	int ret;
-	uint32_t usb_base, cap_base, tmp;
+	struct usb_plat *plat = dev_get_plat(dev);
+	struct usb_ehci *ehci = dev_read_addr_ptr(dev);
+	struct ehci_mxs_priv_data *priv = dev_get_priv(dev);
+	struct ehci_mxs_port *port = &priv->port;
+	enum usb_init_type type = plat->init_type;
 	struct ehci_hccr *hccr;
 	struct ehci_hcor *hcor;
-	const struct ehci_mxs_port *port;
-
-	if ((index < 0) || (index >= ARRAY_SIZE(mxs_port))) {
-		printf("Invalid port index (index = %d)!\n", index);
-		return -EINVAL;
-	}
+	int ret;
 
-	port = &mxs_port[index];
+	priv->ehci = ehci;
+	priv->init_type = type;
 
-	/* Stop the USB port */
-	usb_base = port->usb_regs + 0x100;
-	hccr = (struct ehci_hccr *)usb_base;
-	cap_base = ehci_readl(&hccr->cr_capbase);
-	hcor = (struct ehci_hcor *)(usb_base + HC_LENGTH(cap_base));
+	debug("%s: USB type: %s  reg: 0x%x phy_reg 0x%p\n", __func__,
+	      type == USB_INIT_HOST ? "HOST" : "DEVICE", port->usb_regs,
+	      (uint32_t *)port->phy_regs);
 
-	tmp = ehci_readl(&hcor->or_usbcmd);
-	tmp &= ~CMD_RUN;
-	ehci_writel(&hcor->or_usbcmd, tmp);
+#if CONFIG_IS_ENABLED(DM_REGULATOR)
+	ret = device_get_supply_regulator(dev, "vbus-supply",
+					  &priv->vbus_supply);
+	if (ret)
+		debug("%s: No vbus supply\n", dev->name);
+
+	if (!ret && priv->vbus_supply) {
+		ret = regulator_set_enable(priv->vbus_supply,
+					   (type == USB_INIT_DEVICE) ?
+					   false : true);
+		if (ret) {
+			puts("Error enabling VBUS supply\n");
+			return ret;
+		}
+	}
+#endif
+	ret = __ehci_hcd_init(port, type, &hccr, &hcor);
+	if (ret)
+		return ret;
 
-	/* Disable the PHY */
-	tmp = USBPHY_PWD_RXPWDRX | USBPHY_PWD_RXPWDDIFF |
-		USBPHY_PWD_RXPWD1PT1 | USBPHY_PWD_RXPWDENV |
-		USBPHY_PWD_TXPWDV2I | USBPHY_PWD_TXPWDIBIAS |
-		USBPHY_PWD_TXPWDFS;
-	writel(tmp, &port->phy_regs->hw_usbphy_pwd);
+	mdelay(10);
+	return ehci_register(dev, hccr, hcor, NULL, 0, priv->init_type);
+}
 
-	/* Disable USB clock */
-	ret = ehci_mxs_toggle_clock(port, 0);
+static int ehci_usb_remove(struct udevice *dev)
+{
+	struct ehci_mxs_priv_data *priv = dev_get_priv(dev);
+	struct ehci_mxs_port *port = &priv->port;
+	int ret;
 
-	board_ehci_hcd_exit(index);
+	ret =  ehci_deregister(dev);
+	if (ret)
+		return ret;
 
-	return ret;
+#if CONFIG_IS_ENABLED(DM_REGULATOR)
+	if (priv->vbus_supply) {
+		ret = regulator_set_enable(priv->vbus_supply, false);
+		if (ret) {
+			puts("Error disabling VBUS supply\n");
+			return ret;
+		}
+	}
+#endif
+	return __ehci_hcd_stop(port);
 }
+
+static const struct udevice_id mxs_usb_ids[] = {
+	{ .compatible = "fsl,imx28-usb" },
+	{ }
+};
+
+U_BOOT_DRIVER(usb_mxs) = {
+	.name	= "ehci_mxs",
+	.id	= UCLASS_USB,
+	.of_match = mxs_usb_ids,
+	.of_to_plat = ehci_usb_ofdata_to_platdata,
+	.probe	= ehci_usb_probe,
+	.remove = ehci_usb_remove,
+	.ops	= &ehci_usb_ops,
+	.plat_auto = sizeof(struct usb_plat),
+	.priv_auto = sizeof(struct ehci_mxs_priv_data),
+	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
+};
+#endif /* !CONFIG_IS_ENABLED(DM_USB) */
diff --git a/include/stdio_dev.h b/include/stdio_dev.h
index 8fb9a12..270fa27 100644
--- a/include/stdio_dev.h
+++ b/include/stdio_dev.h
@@ -103,6 +103,7 @@ int drv_lcd_init(void);
 int drv_video_init(void);
 int drv_keyboard_init(void);
 int drv_usbtty_init(void);
+int drv_usbacm_init(void);
 int drv_nc_init(void);
 int drv_jtag_console_init(void);
 int cbmemc_init(void);
diff --git a/lib/Kconfig b/lib/Kconfig
index 38051cc..52d4b27 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -299,6 +299,9 @@ config TRACE_EARLY_ADDR
 	  the size is too small then the message which says the amount of early
 	  data being coped will the the same as the
 
+config CIRCBUF
+	bool "Enable circular buffer support"
+
 source lib/dhry/Kconfig
 
 menu "Security support"
diff --git a/lib/Makefile b/lib/Makefile
index 7950e84..f223892 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -29,7 +29,13 @@ ifneq ($(CONFIG_CHARSET),)
 obj-y += charset.o
 endif
 endif
-obj-$(CONFIG_USB_TTY) += circbuf.o
+
+ifdef CONFIG_USB_TTY
+obj-y += circbuf.o
+else
+obj-$(CONFIG_CIRCBUF) += circbuf.o
+endif
+
 obj-y += crc8.o
 obj-y += crc16.o
 obj-$(CONFIG_ERRNO_STR) += errno_str.o