stmhal: Fix USB MSC so that it unmounts correctly on Mac OS X.

Mac OS X sends a SCSI command to remove the medium when it unmounts a
drive.  If this command is not honoured, then OS X will automatically
remount the drive, making it impossible to eject.  This patch disables
the USB MSC when the right SCSI command is sent.

stmhal/usbd_msc_storage.c

@@ -35,6 +35,11 @@
 #include "diskio.h"
 #include "sdcard.h"
 
+// These are needed to support removal of the medium, so that the USB drive
+// can be unmounted, and won't be remounted automatically.
+static uint8_t flash_removed = 0;
+static uint8_t sdcard_removed = 0;
+
 /******************************************************************************/
 // Callback functions for when the internal flash is the mass storage device
 
@@ -83,6 +88,9 @@ int8_t FLASH_STORAGE_GetCapacity(uint8_t lun, uint32_t *block_num, uint16_t *blo
   * @retval Status
   */
 int8_t FLASH_STORAGE_IsReady(uint8_t lun) {
+    if (flash_removed) {
+        return -1;
+    }
     return 0;
 }
 
@@ -95,6 +103,12 @@ int8_t FLASH_STORAGE_IsWriteProtected(uint8_t lun) {
     return  0;
 }
 
+// Remove the lun
+int8_t FLASH_STORAGE_StopUnit(uint8_t lun) {
+    flash_removed = 1;
+    return 0;
+}
+
 /**
   * @brief  Read data from the medium
   * @param  lun : logical unit number
@@ -150,6 +164,7 @@ const USBD_StorageTypeDef USBD_FLASH_STORAGE_fops = {
     FLASH_STORAGE_GetCapacity,
     FLASH_STORAGE_IsReady,
     FLASH_STORAGE_IsWriteProtected,
+    FLASH_STORAGE_StopUnit,
     FLASH_STORAGE_Read,
     FLASH_STORAGE_Write,
     FLASH_STORAGE_GetMaxLun,
@@ -236,6 +251,9 @@ int8_t SDCARD_STORAGE_GetCapacity(uint8_t lun, uint32_t *block_num, uint16_t *bl
   * @retval Status
   */
 int8_t SDCARD_STORAGE_IsReady(uint8_t lun) {
+    if (sdcard_removed) {
+        return -1;
+    }
     /*
 #ifndef USE_STM3210C_EVAL  
   
@@ -271,6 +289,12 @@ int8_t SDCARD_STORAGE_IsWriteProtected(uint8_t lun) {
     return 0;
 }
 
+// Remove the lun
+int8_t SDCARD_STORAGE_StopUnit(uint8_t lun) {
+    sdcard_removed = 1;
+    return 0;
+}
+
 /**
   * @brief  Read data from the medium
   * @param  lun : logical unit number
@@ -315,6 +339,7 @@ const USBD_StorageTypeDef USBD_SDCARD_STORAGE_fops = {
     SDCARD_STORAGE_GetCapacity,
     SDCARD_STORAGE_IsReady,
     SDCARD_STORAGE_IsWriteProtected,
+    SDCARD_STORAGE_StopUnit,
     SDCARD_STORAGE_Read,
     SDCARD_STORAGE_Write,
     SDCARD_STORAGE_GetMaxLun,

stmhal/usbdev/class/cdc_msc_hid/inc/usbd_cdc_msc_hid.h

@@ -53,6 +53,7 @@ typedef struct _USBD_STORAGE {
   int8_t (* GetCapacity) (uint8_t lun, uint32_t *block_num, uint16_t *block_size);
   int8_t (* IsReady) (uint8_t lun);
   int8_t (* IsWriteProtected) (uint8_t lun);
+  int8_t (* StopUnit)(uint8_t lun);
   int8_t (* Read) (uint8_t lun, uint8_t *buf, uint32_t blk_addr, uint16_t blk_len);
   int8_t (* Write)(uint8_t lun, uint8_t *buf, uint32_t blk_addr, uint16_t blk_len);
   int8_t (* GetMaxLun)(void);

stmhal/usbdev/class/cdc_msc_hid/src/usbd_cdc_msc_hid.c

@@ -583,11 +583,18 @@ static uint8_t USBD_CDC_MSC_HID_Setup(USBD_HandleTypeDef *pdev, USBD_SetupReqTyp
 
     /*
     printf("SU: %x %x %x %x\n", req->bmRequest, req->bRequest, req->wValue, req->wIndex);
+
     This is what we get when MSC is IFACE=0 and CDC is IFACE=1,2:
         SU: 21 22 0 1 -- USB_REQ_TYPE_CLASS | USB_REQ_RECIPIENT_INTERFACE; CDC_SET_CONTROL_LINE_STATE
         SU: 21 20 0 1 -- USB_REQ_TYPE_CLASS | USB_REQ_RECIPIENT_INTERFACE; CDC_SET_LINE_CODING
         SU: a1 fe 0 0 -- 0x80 | USB_REQ_TYPE_CLASS | USB_REQ_RECIPIENT_INTERFACE; BOT_GET_MAX_LUN; 0; 0
         SU: 21 22 3 1 -- USB_REQ_TYPE_CLASS | USB_REQ_RECIPIENT_INTERFACE; CDC_SET_CONTROL_LINE_STATE
+
+    On a Mac OS X, with MSC then CDC:
+        SU: a1 fe 0 0
+        SU: 21 22 2 1
+        SU: 21 22 3 1
+        SU: 21 20 0 1
     */
 
     switch (req->bmRequest & USB_REQ_TYPE_MASK) {
@@ -723,6 +730,11 @@ static uint8_t USBD_CDC_MSC_HID_Setup(USBD_HandleTypeDef *pdev, USBD_SetupReqTyp
     return USBD_OK;
 }
 
+/* unused
+static uint8_t EP0_TxSent(USBD_HandleTypeDef *pdev) {
+}
+*/
+
 static uint8_t USBD_CDC_MSC_HID_EP0_RxReady(USBD_HandleTypeDef *pdev) {
   if((CDC_fops != NULL) && (CDC_ClassData.CmdOpCode != 0xFF)) {
     CDC_fops->Control(CDC_ClassData.CmdOpCode, (uint8_t *)CDC_ClassData.data, CDC_ClassData.CmdLength);
@@ -902,8 +914,8 @@ USBD_ClassTypeDef USBD_CDC_MSC_HID = {
     USBD_CDC_MSC_HID_DataIn,
     USBD_CDC_MSC_HID_DataOut,
     NULL, // SOF
-    NULL,
-    NULL,
+    NULL, // IsoINIncomplete
+    NULL, // IsoOUTIncomplete
     USBD_CDC_MSC_HID_GetCfgDesc,
     USBD_CDC_MSC_HID_GetCfgDesc,
     USBD_CDC_MSC_HID_GetCfgDesc,

stmhal/usbdev/class/cdc_msc_hid/src/usbd_msc_scsi.c

@@ -86,6 +86,7 @@ static int8_t SCSI_ReadFormatCapacity(USBD_HandleTypeDef  *pdev, uint8_t lun, ui
 static int8_t SCSI_ReadCapacity10(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params);
 static int8_t SCSI_RequestSense (USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params);
 static int8_t SCSI_StartStopUnit(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params);
+static int8_t SCSI_AllowMediumRemoval(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params);
 static int8_t SCSI_ModeSense6 (USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params);
 static int8_t SCSI_ModeSense10 (USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params);
 static int8_t SCSI_Write10(USBD_HandleTypeDef  *pdev, uint8_t lun , uint8_t *params);
@@ -122,6 +123,11 @@ int8_t SCSI_ProcessCmd(USBD_HandleTypeDef  *pdev,
                            uint8_t lun, 
                            uint8_t *params)
 {
+    /*
+    if (params[0] != SCSI_READ10 && params[0] != SCSI_WRITE10) {
+        printf("SCSI_ProcessCmd(lun=%d, params=%x, %x)\n", lun, params[0], params[1]);
+    }
+    */
   
   switch (params[0])
   {
@@ -137,7 +143,7 @@ int8_t SCSI_ProcessCmd(USBD_HandleTypeDef  *pdev,
     return SCSI_StartStopUnit(pdev, lun, params);
     
   case SCSI_ALLOW_MEDIUM_REMOVAL:
-    return SCSI_StartStopUnit(pdev, lun, params);
+    return SCSI_AllowMediumRemoval(pdev, lun, params);
     
   case SCSI_MODE_SENSE6:
     return SCSI_ModeSense6 (pdev, lun, params);
@@ -439,6 +445,30 @@ void SCSI_SenseCode(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t sKey, uint8_
 * @retval status
 */
 static int8_t SCSI_StartStopUnit(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
+{
+  USBD_MSC_BOT_HandleTypeDef  *hmsc = pdev->pClassData;   
+  hmsc->bot_data_length = 0;
+
+  // On Mac OS X, when the device is ejected a SCSI_START_STOP_UNIT command is sent.
+  // params[1]==0 means stop, param[1]==1 seems to be something else (happens after the
+  // device is plugged in and mounted for some time, probably a keep alive).
+  // If we get a stop, we must really stop the device so that the Mac does not
+  // automatically remount it.
+  if (params[1] == 0) {
+      ((USBD_StorageTypeDef *)pdev->pUserData)->StopUnit(lun);
+  }
+
+  return 0;
+}
+
+/**
+* @brief  SCSI_AllowMediumRemoval
+*         Process Allow Medium Removal command
+* @param  lun: Logical unit number
+* @param  params: Command parameters
+* @retval status
+*/
+static int8_t SCSI_AllowMediumRemoval(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_t *params)
 {
   USBD_MSC_BOT_HandleTypeDef  *hmsc = pdev->pClassData;   
   hmsc->bot_data_length = 0;