CMSIS-DAP: auto-detect CMSIS-DAP USB VID:PID

The current OpenOCD implementation requires CMSIS-DAP adapter USB
VID:PID values to either be hard-coded in the source or manually
supplied by the user's configuration files.  The CMSIS-DAP
specification stipulates that all compliant adapters should have
"CMSIS-DAP" in the product string.  This should obviate the need
for hard-coding.

This patch was previously submitted as changes 1882, 1883, and 1886
but amendments failed to be registered by the server.  The
functionality was changed from 1886 in response to comments so that
user-supplied VID:PID values overrided the CMSIS-DAP auto-detect.

Change-Id: Ifb2dc217248359f448e0a42bd1527dd744c434b0
Signed-off-by: Peter Lawrence <majbthrd@gmail.com>
Reviewed-on: http://openocd.zylin.com/1888
Tested-by: jenkins
Reviewed-by: Xiaofan <xiaofanc@gmail.com>
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

diff --git a/src/jtag/drivers/cmsis_dap_usb.c b/src/jtag/drivers/cmsis_dap_usb.c
index 5cd117fc41f109450a5664a93160c75b0f29f8ff..29bb15bce0df0387b097ddd30c8c5d4e3210c68b 100644 (file)
--- a/src/jtag/drivers/cmsis_dap_usb.c
+++ b/src/jtag/drivers/cmsis_dap_usb.c
@@ -58,8 +58,8 @@
 
 #define MAX_USB_IDS 8
 /* vid = pid = 0 marks the end of the list */
-static uint16_t cmsis_dap_vid[MAX_USB_IDS + 1] = { 0xc251, 0xc251, 0xc251, 0x0d28, 0x03eb, 0 };
-static uint16_t cmsis_dap_pid[MAX_USB_IDS + 1] = { 0xf001, 0xf002, 0x2722, 0x0204, 0x2111, 0 };
+static uint16_t cmsis_dap_vid[MAX_USB_IDS + 1] = { 0 };
+static uint16_t cmsis_dap_pid[MAX_USB_IDS + 1] = { 0 };
 
 #define PACKET_SIZE       (64 + 1)     /* 64 bytes plus report id */
 #define USB_TIMEOUT       1000
@@ -159,17 +159,52 @@ static int cmsis_dap_usb_open(void)
 {
        hid_device *dev = NULL;
        int i;
+       struct hid_device_info *devs, *cur_dev;
+       unsigned short target_vid, target_pid;
+
+       target_vid = 0;
+       target_pid = 0;
+
+       /*
+       The CMSIS-DAP specification stipulates:
+       "The Product String must contain "CMSIS-DAP" somewhere in the string. This is used by the
+       debuggers to idenify a CMSIS-DAP compliant Debug Unit that is connected to a host computer."
+       */
+       devs = hid_enumerate(0x0, 0x0);
+       cur_dev = devs;
+       while (NULL != cur_dev) {
+               if ((0 == cmsis_dap_vid[0]) && wcsstr(cur_dev->product_string, L"CMSIS-DAP")) {
+                       /*
+                       if the user hasn't specified VID:PID *and*
+                       product string contains "CMSIS-DAP", pick it
+                       */
+                       break;
+               } else {
+                       /*
+                       otherwise, exhaustively compare against all VID:PID in list
+                       */
+                       for (i = 0; cmsis_dap_vid[i] || cmsis_dap_pid[i]; i++) {
+                               if ((cmsis_dap_vid[i] == cur_dev->vendor_id) && (cmsis_dap_pid[i] == cur_dev->product_id))
+                                       break;
+                       }
+               }
+
+               cur_dev = cur_dev->next;
+       }
+
+       if (NULL != cur_dev) {
+               target_vid = cur_dev->vendor_id;
+               target_pid = cur_dev->product_id;
+       }
+
+       hid_free_enumeration(devs);
 
        if (hid_init() != 0) {
                LOG_ERROR("unable to open HIDAPI");
                return ERROR_FAIL;
        }
 
-       for (i = 0; cmsis_dap_vid[i] || cmsis_dap_pid[i]; i++) {
-               dev = hid_open(cmsis_dap_vid[i], cmsis_dap_pid[i], NULL);
-               if (dev != NULL)
-                       break;
-       }
+       dev = hid_open(target_vid, target_pid, NULL);
 
        if (dev == NULL) {
                LOG_ERROR("unable to open CMSIS-DAP device");
@@ -196,7 +231,7 @@ static int cmsis_dap_usb_open(void)
        int packet_size = PACKET_SIZE;
 
        /* atmel cmsis-dap uses 512 byte reports */
-       if (cmsis_dap_vid[i] == 0x03eb && cmsis_dap_pid[i] == 0x2111)
+       if (target_vid == 0x03eb && target_pid == 0x2111)
                packet_size = 512 + 1;
 
        cmsis_dap_handle->packet_buffer = malloc(packet_size);