From fb93abea9e78ac0e9b9e824fe1d4a38f79152516 Mon Sep 17 00:00:00 2001
From: Keir Fraser <keir.xen@gmail.com>
Date: Mon, 26 Apr 2021 12:10:54 +0100
Subject: [PATCH] New firmware command CMD_GET_PIN to read an interface pin's
 voltage level.

---
 inc/cdc_acm_protocol.h |  5 ++++-
 src/f1/floppy.c        |  5 +++++
 src/f7/floppy.c        | 14 ++++++++++++++
 src/floppy.c           | 29 +++++++++++++++++++++++++++++
 4 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/inc/cdc_acm_protocol.h b/inc/cdc_acm_protocol.h
index 0fcbe3e..9b032aa 100644
--- a/inc/cdc_acm_protocol.h
+++ b/inc/cdc_acm_protocol.h
@@ -67,7 +67,10 @@
 #define CMD_SOURCE_BYTES   18
 /* CMD_SINK_BYTES, length=6. Argument is gw_sink_source_bytes. */
 #define CMD_SINK_BYTES     19
-#define CMD_MAX            19
+/* CMD_GET_PIN, length=3, pin#. Successful ACK is followed by pin-level byte
+ * (1=High, 0=Low). Unsupported pin returns ACK_BAD_PIN and no pin level. */
+#define CMD_GET_PIN        20
+#define CMD_MAX            20
 
 
 /*
diff --git a/src/f1/floppy.c b/src/f1/floppy.c
index c37d132..e12dae3 100644
--- a/src/f1/floppy.c
+++ b/src/f1/floppy.c
@@ -173,6 +173,11 @@ static uint8_t drive_motor(uint8_t nr, bool_t on)
     return ACK_OKAY;
 }
 
+static uint8_t mcu_get_floppy_pin(unsigned int pin, uint8_t *p_level)
+{
+    return ACK_BAD_PIN;
+}
+
 static uint8_t set_user_pin(unsigned int pin, unsigned int level)
 {
     if (pin != 2)
diff --git a/src/f7/floppy.c b/src/f7/floppy.c
index 03aed2e..6281272 100644
--- a/src/f7/floppy.c
+++ b/src/f7/floppy.c
@@ -265,6 +265,20 @@ static uint8_t drive_motor(uint8_t nr, bool_t on)
 
 }
 
+static uint8_t mcu_get_floppy_pin(unsigned int pin, uint8_t *p_level)
+{
+    switch (gw_info.hw_submodel) {
+    case F7SM_v3:
+    case F7SM_lightning_plus:
+        if (pin == 34) {
+            *p_level = gpio_read_pin(gpioc, 2);
+            return ACK_OKAY;
+        }
+        break;
+    }
+    return ACK_BAD_PIN;
+}
+
 static uint8_t set_user_pin(unsigned int pin, unsigned int level)
 {
     const struct pin_mapping *upin;
diff --git a/src/floppy.c b/src/floppy.c
index e669dcb..b6721e1 100644
--- a/src/floppy.c
+++ b/src/floppy.c
@@ -296,6 +296,26 @@ static bool_t set_bus_type(uint8_t type)
     return TRUE;
 }
 
+static uint8_t get_floppy_pin(unsigned int pin, uint8_t *p_level)
+{
+    uint8_t rc = ACK_OKAY;
+    switch (pin) {
+    case 8:
+        *p_level = get_index();
+        break;
+    case 26:
+        *p_level = get_trk0();
+        break;
+    case 28:
+        *p_level = get_wrprot();
+        break;
+    default:
+        rc = mcu_get_floppy_pin(pin, p_level);
+        break;
+    }
+    return rc;
+}
+
 static void floppy_reset(void)
 {
     floppy_state = ST_inactive;
@@ -1262,6 +1282,15 @@ static void process_command(void)
         u_buf[1] = set_user_pin(pin, level);
         goto out;
     }
+    case CMD_GET_PIN: {
+        uint8_t pin = u_buf[2];
+        if (len != 3)
+            goto bad_command;
+        u_buf[1] = get_floppy_pin(pin, &u_buf[2]);
+        if (u_buf[1] == ACK_OKAY)
+            resp_sz += 1;
+        goto out;
+    }
     case CMD_RESET: {
         if (len != 2)
             goto bad_command;