libpayload: usbmsc: Factor out usb_msc_force_init() function

We're planning to have a use case with a custom USB device that
implements the USB mass storage protocol on its bulk endpoints, but does
not have the normal MSC class/protocol interface descriptors and does
not support class-specific control requests (Get Max LUN and Bulk-Only
Reset). We'd like to identify/enumerate the device via
usb_generic_create() in our payload but then reuse all the normal MSC
driver code. In order to make that possible, this patch factors a new
usb_msc_force_init() function out of usb_msc_init() which will
initialize an MSC device without checking its descriptors. It also adds
some "quirks" flags that allow devices registered this way to customize
behavior of the MSC stack.

Change-Id: I50392128409cb2a879954f234149a5e3b060a229
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34227
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

1 files changed, 19 insertions, 9 deletions

diff --git a/payloads/libpayload/drivers/usb/usbmsc.c b/payloads/libpayload/drivers/usb/usbmsc.c
index d793e34ba7..2412e99af3 100644
--- a/payloads/libpayload/drivers/usb/usbmsc.c
+++ b/payloads/libpayload/drivers/usb/usbmsc.c
@@ -157,6 +157,9 @@ reset_transport (usbdev_t *dev)
 	dr.wIndex = 0;
 	dr.wLength = 0;
 
+	if (MSC_INST (dev)->quirks & USB_MSC_QUIRK_NO_RESET)
+		return MSC_COMMAND_FAIL;
+
 	/* if any of these fails, detach device, as we are lost */
 	if (dev->controller->control (dev, OUT, sizeof (dr), &dr, 0, 0) < 0 ||
 			clear_stall (MSC_INST (dev)->bulk_in) ||
@@ -185,7 +188,8 @@ initialize_luns (usbdev_t *dev)
 	dr.wValue = 0;
 	dr.wIndex = 0;
 	dr.wLength = 1;
-	if (dev->controller->control (dev, IN, sizeof (dr), &dr,
+	if (MSC_INST (dev)->quirks & USB_MSC_QUIRK_NO_LUNS ||
+	    dev->controller->control (dev, IN, sizeof (dr), &dr,
 			sizeof (msc->num_luns), &msc->num_luns) < 0)
 		msc->num_luns = 0;	/* assume only 1 lun if req fails */
 	msc->num_luns++;	/* Get Max LUN returns number of last LUN */
@@ -600,14 +604,6 @@ usb_msc_test_unit_ready (usbdev_t *dev)
 void
 usb_msc_init (usbdev_t *dev)
 {
-	int i;
-
-	/* init .data before setting .destroy */
-	dev->data = NULL;
-
-	dev->destroy = usb_msc_destroy;
-	dev->poll = usb_msc_poll;
-
 	configuration_descriptor_t *cd =
 		(configuration_descriptor_t *) dev->configuration;
 	interface_descriptor_t *interface =
@@ -634,6 +630,19 @@ usb_msc_init (usbdev_t *dev)
 		return;
 	}
 
+	usb_msc_force_init (dev, 0);
+}
+
+void usb_msc_force_init (usbdev_t *dev, u32 quirks)
+{
+	int i;
+
+	/* init .data before setting .destroy */
+	dev->data = NULL;
+
+	dev->destroy = usb_msc_destroy;
+	dev->poll = usb_msc_poll;
+
 	dev->data = malloc (sizeof (usbmsc_inst_t));
 	if (!dev->data)
 		fatal("Not enough memory for USB MSC device.\n");
@@ -641,6 +650,7 @@ usb_msc_init (usbdev_t *dev)
 	MSC_INST (dev)->bulk_in = 0;
 	MSC_INST (dev)->bulk_out = 0;
 	MSC_INST (dev)->usbdisk_created = 0;
+	MSC_INST (dev)->quirks = quirks;
 
 	for (i = 1; i <= dev->num_endp; i++) {
 		if (dev->endpoints[i].endpoint == 0)