Add disk inserted sensor pin interface option.

"in" and "nin" can configure a pin to indicate the status of
the disk inserted sensor. This ignores the drive select pin.

This is intended to be used with the Sharp X68000 (with the
addition of additional hardware - on the X68000 this is gated
by the OPTION SELECT line).

examples/FF.CFG

@@ -51,7 +51,9 @@ host = unspecified
 # ndens: Logical complement of above
 # chg: Disk changed (Changed = 0v)
 # nchg: Logical complement of above
-# Values: auto, nc, low, high, rdy, nrdy, dens, ndens, chg, nchg
+# in: Disk inserted (Inserted = 0v), ignores drive-select
+# nin: Logical complement of above
+# Values: auto, nc, low, high, rdy, nrdy, dens, ndens, chg, nchg, in, nin
 pin02 = auto
 pin34 = auto
 

inc/config.h

@@ -130,11 +130,13 @@ struct packed ff_cfg {
 #define PIN_rdy    (outp_rdy + 1)
 #define PIN_dens   (outp_hden + 1)
 #define PIN_chg    (outp_dskchg + 1)
+#define PIN_in     (outp_in + 1)
 #define PIN_invert 0x80
 #define PIN_low    (PIN_high | PIN_invert)
 #define PIN_nrdy   (PIN_rdy | PIN_invert)
 #define PIN_ndens  (PIN_dens | PIN_invert)
 #define PIN_nchg   (PIN_chg | PIN_invert)
+#define PIN_nin    (PIN_in | PIN_invert)
     uint8_t pin02, pin34;
     uint8_t head_settle_ms;
     uint8_t oled_contrast;

inc/floppy.h

@@ -35,7 +35,8 @@
 #define outp_wrprot 3
 #define outp_rdy    4
 #define outp_hden   5
-#define outp_nr     6
+#define outp_in     6
+#define outp_nr     7
 #define outp_unused outp_nr
 
 #define verbose_image_log FALSE

src/floppy.c

@@ -38,6 +38,7 @@ static always_inline void drive_change_pin(
     struct drive *drv, uint8_t pin, bool_t assert);
 static always_inline void drive_change_output(
     struct drive *drv, uint8_t outp, bool_t assert);
+static void disk_inserted_output(uint8_t outp, bool_t assert);
 
 #include "floppy_generic.c"
 
@@ -130,6 +131,18 @@ static void drive_change_output(
     drive_change_pin(drv, pin, assert);
 }
 
+static void disk_inserted_output(uint8_t outp, bool_t assert)
+{
+    if (pin02 == outp) {
+        GPIO gpio = pin_02 < 16 ? gpiob : gpioa;
+        gpio_write_pin(gpio, pin_02 & 15, assert ^ pin02_inverted);
+    }
+    if (pin34 == outp) {
+        GPIO gpio = pin_34 < 16 ? gpiob : gpioa;
+        gpio_write_pin(gpio, pin_34 & 15, assert ^ pin34_inverted);
+    }
+}
+
 static void update_amiga_id(struct drive *drv, bool_t amiga_hd_id)
 {
     /* JC and pin 34 are overridden only for the Amiga interface. */
@@ -210,6 +223,7 @@ void floppy_cancel(void)
     barrier();
     drive_change_output(drv, outp_index, FALSE);
     drive_change_output(drv, outp_dskchg, TRUE);
+    disk_inserted_output(outp_in, TRUE);
 }
 
 void floppy_set_fintf_mode(void)
@@ -223,6 +237,7 @@ void floppy_set_fintf_mode(void)
         [FINTF_AMIGA]       = "Amiga"
     };
     static const char *const outp_name[] = {
+        [outp_in] = "in",
         [outp_dskchg] = "chg",
         [outp_rdy] = "rdy",
         [outp_hden] = "dens",
@@ -320,6 +335,7 @@ void floppy_init(void)
     drive_change_output(drv, outp_dskchg, TRUE);
     drive_change_output(drv, outp_wrprot, TRUE);
     drive_change_output(drv, outp_trk0,   TRUE);
+    disk_inserted_output(outp_in, TRUE);
 
     floppy_init_irqs();
 
@@ -352,6 +368,7 @@ void floppy_insert(unsigned int unit, struct slot *slot)
     update_amiga_id(drv, im->stk_per_rev > stk_ms(300));
     if (!(slot->attributes & AM_RDO))
         drive_change_output(drv, outp_wrprot, FALSE);
+    disk_inserted_output(outp_in, FALSE);
     barrier();
     drv->inserted = TRUE;
     motor_chgrst_update_status(drv); /* update RDY + motor state */

src/gotek/floppy.c

@@ -305,8 +305,9 @@ static void IRQ_STEP_changed(void)
 
     /* Deassert DSKCHG if a disk is inserted. */
     if ((drv->outp & m(outp_dskchg)) && drv->inserted
-        && (ff_cfg.chgrst == CHGRST_step))
+        && (ff_cfg.chgrst == CHGRST_step)) {
         drive_change_output(drv, outp_dskchg, FALSE);
+    }
 
     /* Do we accept this STEP command? */
     if ((drv->step.state & STEP_active) /* Already mid-step? */

src/main.c

@@ -911,6 +911,7 @@ static uint8_t parse_pin_str(const char *s)
         : !strcmp(s, "rdy") ? PIN_rdy
         : !strcmp(s, "dens") ? PIN_dens
         : !strcmp(s, "chg") ? PIN_chg
+        : !strcmp(s, "in") ? PIN_in
         : PIN_auto;
     return pin;
 }