stm32/usbdev: Add support for MSC-only USB device class.

dpgeorge · dpgeorge · commit 3130424b5427 · 2018-02-01T15:47:16.000+11:00
Select this mode in boot.py via: pyb.usb_mode('MSC')
diff --git a/ports/stm32/usb.c b/ports/stm32/usb.c
@@ -293,6 +293,11 @@ STATIC mp_obj_t pyb_usb_mode(size_t n_args, const mp_obj_t *pos_args, mp_map_t *
             pid = USBD_PID_CDC;
         }
         mode = USBD_MODE_CDC;
+    } else if (strcmp(mode_str, "MSC") == 0) {
+        if (args[2].u_int == -1) {
+            pid = USBD_PID_MSC;
+        }
+        mode = USBD_MODE_MSC;
     } else {
         goto bad_mode;
     }
diff --git a/ports/stm32/usb.h b/ports/stm32/usb.h
@@ -35,6 +35,7 @@
 #define USBD_PID_CDC_MSC (0x9800)
 #define USBD_PID_CDC_HID (0x9801)
 #define USBD_PID_CDC     (0x9802)
+#define USBD_PID_MSC     (0x9803)
 
 typedef enum {
     PYB_USB_STORAGE_MEDIUM_NONE = 0,
diff --git a/ports/stm32/usbdev/class/src/usbd_cdc_msc_hid.c b/ports/stm32/usbdev/class/src/usbd_cdc_msc_hid.c
@@ -28,6 +28,7 @@
 #include "usbd_ioreq.h"
 #include "usbd_cdc_msc_hid.h"
 
+#define MSC_TEMPLATE_CONFIG_DESC_SIZE (32)
 #define CDC_TEMPLATE_CONFIG_DESC_SIZE (67)
 #define CDC_MSC_TEMPLATE_CONFIG_DESC_SIZE (98)
 #define CDC_HID_TEMPLATE_CONFIG_DESC_SIZE (107)
@@ -89,6 +90,54 @@ __ALIGN_BEGIN static uint8_t USBD_CDC_MSC_HID_DeviceQualifierDesc[USB_LEN_DEV_QU
 };
 */
 
+// USB MSC device Configuration Descriptor
+static const uint8_t msc_template_config_desc[MSC_TEMPLATE_CONFIG_DESC_SIZE] = {
+    //--------------------------------------------------------------------------
+    // Configuration Descriptor
+    0x09,   // bLength: Configuration Descriptor size
+    USB_DESC_TYPE_CONFIGURATION, // bDescriptorType: Configuration
+    LOBYTE(MSC_TEMPLATE_CONFIG_DESC_SIZE), // wTotalLength: no of returned bytes
+    HIBYTE(MSC_TEMPLATE_CONFIG_DESC_SIZE),
+    0x01,   // bNumInterfaces: 1 interfaces
+    0x01,   // bConfigurationValue: Configuration value
+    0x00,   // iConfiguration: Index of string descriptor describing the configuration
+    0x80,   // bmAttributes: bus powered; 0xc0 for self powered
+    0xfa,   // bMaxPower: in units of 2mA
+
+    //==========================================================================
+    // MSC only has 1 interface so doesn't need an IAD
+
+    //--------------------------------------------------------------------------
+    // Interface Descriptor
+    0x09,   // bLength: Interface Descriptor size
+    USB_DESC_TYPE_INTERFACE, // bDescriptorType: interface descriptor
+    MSC_IFACE_NUM_WITH_CDC, // bInterfaceNumber: Number of Interface
+    0x00,   // bAlternateSetting: Alternate setting
+    0x02,   // bNumEndpoints
+    0x08,   // bInterfaceClass: MSC Class
+    0x06,   // bInterfaceSubClass : SCSI transparent
+    0x50,   // nInterfaceProtocol
+    0x00,   // iInterface:
+
+    // Endpoint IN descriptor
+    0x07,                           // bLength: Endpoint descriptor length
+    USB_DESC_TYPE_ENDPOINT,         // bDescriptorType: Endpoint descriptor type
+    MSC_IN_EP,                      // bEndpointAddress: IN, address 3
+    0x02,                           // bmAttributes: Bulk endpoint type
+    LOBYTE(MSC_MAX_PACKET),         // wMaxPacketSize
+    HIBYTE(MSC_MAX_PACKET),
+    0x00,                           // bInterval: ignore for Bulk transfer
+
+    // Endpoint OUT descriptor
+    0x07,                           // bLength: Endpoint descriptor length
+    USB_DESC_TYPE_ENDPOINT,         // bDescriptorType: Endpoint descriptor type
+    MSC_OUT_EP,                     // bEndpointAddress: OUT, address 3
+    0x02,                           // bmAttributes: Bulk endpoint type
+    LOBYTE(MSC_MAX_PACKET),         // wMaxPacketSize
+    HIBYTE(MSC_MAX_PACKET),
+    0x00,                           // bInterval: ignore for Bulk transfer
+};
+
 // USB CDC MSC device Configuration Descriptor
 static const uint8_t cdc_msc_template_config_desc[CDC_MSC_TEMPLATE_CONFIG_DESC_SIZE] = {
     //--------------------------------------------------------------------------
@@ -554,6 +603,11 @@ int USBD_SelectMode(usbd_cdc_msc_hid_state_t *usbd, uint32_t mode, USBD_HID_Mode
 
     // construct config desc
     switch (usbd->usbd_mode) {
+        case USBD_MODE_MSC:
+            usbd->usbd_config_desc_size = sizeof(msc_template_config_desc);
+            memcpy(usbd->usbd_config_desc, msc_template_config_desc, sizeof(msc_template_config_desc));
+            break;
+
         case USBD_MODE_CDC_MSC:
             usbd->usbd_config_desc_size = sizeof(cdc_msc_template_config_desc);
             memcpy(usbd->usbd_config_desc, cdc_msc_template_config_desc, sizeof(cdc_msc_template_config_desc));

Original file line number	Diff line number	Diff line change
`@@ -293,6 +293,11 @@ STATIC mp_obj_t pyb_usb_mode(size_t n_args, const mp_obj_t pos_args, mp_map_t `
`293`	`293`	`pid = USBD_PID_CDC;`
`294`	`294`	`}`
`295`	`295`	`mode = USBD_MODE_CDC;`
	`296`	`+ } else if (strcmp(mode_str, "MSC") == 0) {`
	`297`	`+ if (args[2].u_int == -1) {`
	`298`	`+ pid = USBD_PID_MSC;`
	`299`	`+ }`
	`300`	`+ mode = USBD_MODE_MSC;`
`296`	`301`	`} else {`
`297`	`302`	`goto bad_mode;`
`298`	`303`	`}`