testmode: Add a test-headers command

inc/testmode.h

@@ -0,0 +1,44 @@
+/*
+ * testmode.h
+ * 
+ * Greaseweazle test-mode command protocol. Subject to change!
+ * 
+ * Written & released by Keir Fraser <[email protected]>
+ * 
+ * This is free and unencumbered software released into the public domain.
+ * See the file COPYING for more details, or visit <http://unlicense.org>.
+ */
+
+#define CMD_option_bytes 0
+#define CMD_pins         1
+#define CMD_led          2
+#define CMD_test_headers 3
+
+/* CMD_test_headers return code in rsp.u.x[0] */
+#define TESTHEADER_success 100
+
+struct cmd {
+    uint32_t cmd;
+    union {
+        uint8_t pins[64/8];
+        uint32_t x[28/4];
+    } u;
+};
+
+struct rsp {
+    union {
+        uint8_t opt[32];
+        uint8_t pins[64/8];
+        uint32_t x[32/4];
+    } u;
+};
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "Linux"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

src/mcu/at32f4/testmode.c

@@ -28,7 +28,7 @@ const struct pin_mapping testmode_out_pins[] = {
 
 void testmode_get_option_bytes(void *buf)
 {
-    memcpy(buf, (void *)0x1ffff800, 16);
+    memcpy(buf, (void *)0x1ffff800, 32);
 }
 
 /*

src/testmode.c

@@ -7,25 +7,7 @@
  * See the file COPYING for more details, or visit <http://unlicense.org>.
  */
 
-#define CMD_option_bytes 0
-#define CMD_pins         1
-#define CMD_led          2
-
-struct cmd {
-    uint32_t cmd;
-    union {
-        uint8_t pins[64/8];
-        uint32_t x[28/4];
-    } u;
-};
-
-struct rsp {
-    union {
-        uint8_t opt[32];
-        uint8_t pins[64/8];
-        uint32_t x[32/4];
-    } u;
-};
+#include "testmode.h"
 
 #define TEST_BIT(p,n) (!!((p)[(n)/8] & (1<<((n)&7))))
 #define SET_BIT(p,n) ((p)[(n)/8] |= (1<<((n)&7)))
@@ -76,6 +58,55 @@ static void get_pins(uint8_t *pins)
     }
 }
 
+static unsigned int testmode_test_headers(void)
+{
+    int i, rc = TESTHEADER_success;
+    bool_t keep_pa9_high = FALSE;
+
+#ifndef NDEBUG
+    return rc;
+#endif
+
+#if MCU == AT32F4
+    if (at32f4_series == AT32F415) {
+        /* AT32F415: PA9 LOW trips OTG VbusBSen and drops the USB connection. 
+         * See Datasheet Table 5 Footnote 8. */
+        keep_pa9_high = TRUE;
+    }
+#endif
+
+    /* Can RXI and TXO pull themselves up and down? */
+    for (i = keep_pa9_high ? 1 : 0; i < 2; i++) {
+        gpio_configure_pin(gpioa, 9+i, GPI_pull_down);
+        delay_ms(1);
+        rc++;
+        if (gpio_read_pin(gpioa, 9+i) != LOW)
+            goto out;
+        gpio_configure_pin(gpioa, 9+i, GPI_pull_up);
+        delay_ms(1);
+        rc++;
+        if (gpio_read_pin(gpioa, 9+i) != HIGH)
+            goto out;
+    }
+
+    /* Are RXI and TXO shorted? */
+    for (i = keep_pa9_high ? 1 : 0; i < 2; i++) {
+        gpio_configure_pin(gpioa, 9+i, GPO_pushpull(IOSPD_LOW, LOW));
+        delay_ms(1);
+        rc++;
+        if (gpio_read_pin(gpioa, 10-i) != HIGH)
+            goto out;
+        gpio_configure_pin(gpioa, 9+i, GPI_pull_up);
+    }
+
+    rc = TESTHEADER_success;
+
+out:
+    for (i = 0; i < 2; i++)
+        gpio_configure_pin(gpioa, 9+i, GPI_pull_up);
+    return rc;
+}
+
 void testmode_process(void)
 {
     int len = ep_rx_ready(EP_RX);
@@ -106,6 +137,10 @@ void testmode_process(void)
         act_led(!!cmd.u.pins[0]);
         break;
     }
+    case CMD_test_headers: {
+        rsp.u.x[0] = testmode_test_headers();
+        break;
+    }
     }
 
     usb_write(EP_TX, &rsp, 32);