apple2: initial support

Makefile

@@ -15,20 +15,23 @@ export ROOT := $(CURDIR)
 prod-%: FORCE
 	$(MAKE) target mcu=$* target=bootloader level=prod
 	$(MAKE) target mcu=$* target=floppy level=prod
+	$(MAKE) target mcu=$* target=apple2 level=prod
 	$(MAKE) target mcu=$* target=quickdisk level=prod
 	$(MAKE) target mcu=$* target=bl_update level=prod
 	$(MAKE) target mcu=$* target=io_test level=prod
 
 debug-%: FORCE
 	$(MAKE) target mcu=$* target=bootloader level=debug
 	$(MAKE) target mcu=$* target=floppy level=debug
+	$(MAKE) target mcu=$* target=apple2 level=debug
 	$(MAKE) target mcu=$* target=quickdisk level=debug
 	$(MAKE) target mcu=$* target=bl_update level=debug
 	$(MAKE) target mcu=$* target=io_test level=debug
 
 logfile-%: FORCE
 	$(MAKE) target mcu=$* target=bootloader level=logfile
 	$(MAKE) target mcu=$* target=floppy level=logfile
+	$(MAKE) target mcu=$* target=apple2 level=logfile
 	$(MAKE) target mcu=$* target=quickdisk level=logfile
 
 all-%: FORCE prod-% debug-% logfile-% ;
@@ -65,6 +68,12 @@ _legacy_dist: FORCE
 	$(PYTHON) $(ROOT)/scripts/mk_update.py old \
 	  $(t)/alt/logfile/$(PROJ)-logfile-$(VER).upd \
 	  out/$(mcu)/logfile/floppy/target.bin & \
+	$(PYTHON) $(ROOT)/scripts/mk_update.py old \
+	  $(t)/alt/apple2/$(PROJ)-apple2-$(VER).upd \
+	  out/$(mcu)/$(level)/apple2/target.bin & \
+	$(PYTHON) $(ROOT)/scripts/mk_update.py old \
+	  $(t)/alt/apple2/logfile/$(PROJ)-apple2-logfile-$(VER).upd \
+	  out/$(mcu)/logfile/apple2/target.bin & \
 	$(PYTHON) $(ROOT)/scripts/mk_update.py old \
 	  $(t)/alt/quickdisk/$(PROJ)-quickdisk-$(VER).upd \
 	  out/$(mcu)/$(level)/quickdisk/target.bin & \
@@ -89,6 +98,12 @@ _dist: FORCE
 	$(PYTHON) $(ROOT)/scripts/mk_update.py new \
 	  $(t)/alt/logfile/$(PROJ)-logfile-$(VER).upd \
 	  out/$(mcu)/logfile/floppy/target.bin $(mcu) & \
+	$(PYTHON) $(ROOT)/scripts/mk_update.py new \
+	  $(t)/alt/apple2/$(PROJ)-apple2-$(VER).upd \
+	  out/$(mcu)/$(level)/apple2/target.bin $(mcu) & \
+	$(PYTHON) $(ROOT)/scripts/mk_update.py new \
+	  $(t)/alt/apple2/logfile/$(PROJ)-apple2-logfile-$(VER).upd \
+	  out/$(mcu)/logfile/apple2/target.bin $(mcu) & \
 	$(PYTHON) $(ROOT)/scripts/mk_update.py new \
 	  $(t)/alt/quickdisk/$(PROJ)-quickdisk-$(VER).upd \
 	  out/$(mcu)/$(level)/quickdisk/target.bin $(mcu) & \
@@ -106,6 +121,7 @@ dist: FORCE all
 	mkdir -p $(t)/alt/bootloader
 	mkdir -p $(t)/alt/logfile
 	mkdir -p $(t)/alt/io-test
+	mkdir -p $(t)/alt/apple2/logfile
 	mkdir -p $(t)/alt/quickdisk/logfile
 	$(MAKE) _legacy_dist mcu=stm32f105 level=$(level) t=$(t)
 	$(MAKE) _dist mcu=stm32f105 n=at415-st105 level=$(level) t=$(t)

Rules.mk

@@ -42,6 +42,11 @@ ifeq ($(logfile),y)
 FLAGS += -DLOGFILE=1
 endif
 
+ifeq ($(apple2),y)
+floppy := y
+FLAGS += -DAPPLE2=1
+endif
+
 ifeq ($(quickdisk),y)
 FLAGS += -DQUICKDISK=1
 endif

inc/floppy.h

@@ -22,6 +22,12 @@
 #define is_quickdisk FALSE
 #endif
 
+#if defined(APPLE2)
+#define WDATA_TOGGLE TRUE
+#else
+#define WDATA_TOGGLE FALSE
+#endif
+
 #define FINTF_SHUGART     0
 #define FINTF_IBMPC       1
 #define FINTF_IBMPC_HDOUT 2

src/floppy.c

@@ -122,7 +122,12 @@ static void drive_change_output(
     switch (outp) {
     case outp_index:  pin = pin_08; break;
     case outp_trk0:   pin = pin_26; break;
-    case outp_wrprot: pin = pin_28; break;
+    case outp_wrprot:
+        pin = pin_28;
+#if defined(APPLE2)
+        assert ^= 1;
+#endif
+        break;
     default:
         _drive_change_output(drv, outp, assert);
         return;

src/floppy_generic.c

@@ -262,7 +262,11 @@ static void timer_dma_init(void)
     tim_rdata->ccmr1 = (TIM_CCMR1_CC2S(TIM_CCS_OUTPUT) |
                         TIM_CCMR1_OC2M(TIM_OCM_PWM1));
     tim_rdata->ccer = TIM_CCER_CC2E | ((O_TRUE==0) ? TIM_CCER_CC2P : 0);
+#if defined(APPLE2)
+    tim_rdata->ccr2 = sampleclk_ns(1000);
+#else
     tim_rdata->ccr2 = sampleclk_ns(400);
+#endif
     tim_rdata->dier = TIM_DIER_UDE;
     tim_rdata->cr2 = 0;
 
@@ -290,7 +294,7 @@ static void timer_dma_init(void)
     tim_wdata->psc = (SYSCLK_MHZ/SAMPLECLK_MHZ) - 1;
     tim_wdata->arr = 0xffff;
     tim_wdata->ccmr1 = TIM_CCMR1_CC1S(TIM_CCS_INPUT_TI1);
-    tim_wdata->dier = TIM_DIER_CC1DE;
+    tim_wdata->dier = TIM_DIER_CC1DE | (WDATA_TOGGLE ? TIM_DIER_CC1IE : 0);
     tim_wdata->cr2 = 0;
 
     /* DMA setup: From the WDATA Timer's CCRx into a circular buffer. */

src/gotek/board.c

@@ -83,6 +83,12 @@ unsigned int board_get_buttons(void)
     if (mcu_package == MCU_LQFP64)
         x &= _rbit32(gpioc->idr) >> 23;
     x = ~x & 7;
+
+#if defined(APPLE2)
+    /* Apple 2: QFN32 select pin PA10 is reassigned as stepper phase #0. */
+    if (mcu_package == MCU_QFN32)
+        return x;
+#endif
     if (has_kc30_header) {
         /* KC30 Select pin, Artery models only: 
          *  PF6/PH2 = Select; except QFN32: PA10 = Select. */
@@ -91,6 +97,7 @@ unsigned int board_get_buttons(void)
                              : kc30_sel_gpio->idr >> (kc30_sel_pin-2));
         x |= ~kc30 & 4;
     }
+
     return x;
 }
 
@@ -281,6 +288,17 @@ void board_init(void)
 
     }
 
+#if defined(APPLE2)
+#if defined(NDEBUG)
+    /* Normal build: Two phases use UART RX/TX. */
+    pa_skip |= m(9) | m(10);
+#else
+    /* Debug build: Move the two UART phases to the KC30 header. */
+    pa_skip |= m(6) | m(15);
+    has_kc30_header = 0;
+#endif
+#endif
+
     gpio_pull_up_pins(gpioa, ~pa_skip);
     gpio_pull_up_pins(gpiob, ~pb_skip);
 }

src/gotek/floppy.c

@@ -14,8 +14,20 @@
 
 /* Input pins: DIR=PB0, STEP=PA1, SELA=PA0, SELB=PA3, WGATE=PB9, SIDE=PB4, 
  *             MOTOR=PA15/PB15 */
+#if defined(APPLE2)
+#if defined(NDEBUG)
+#define pin_pha0   10 /* PA10 - (aka UART RX (PCB silk J4)) */
+#define pin_pha1    9 /* PA9  - (aka UART TX) */
+#else
+#define pin_pha0    6 /* PA6  - (aka SFRKC30 Rotary DAT (PCB silk J8)) */
+#define pin_pha1   15 /* PA15 - (aka SRFKC30 Rotary CLK) */
+#endif
+#define pin_pha2    0 /* PB0 */
+#define pin_pha3    1 /* PA1 */
+#else
 #define pin_dir     0 /* PB0 */
 #define pin_step    1 /* PA1 */
+#endif
 #define pin_sel0    0 /* PA0 */
 #define pin_sel1    3 /* PA3 */
 static uint8_t pin_wgate = 9; /* PB9 */
@@ -46,17 +58,32 @@ DEFINE_IRQ(dma_wdata_irq, "IRQ_wdata_dma");
 #define dma_rdata_irq DMA1_CH3_IRQ
 DEFINE_IRQ(dma_rdata_irq, "IRQ_rdata_dma");
 
+/* Head step handling. */
+#if defined(APPLE2)
+static struct timer step_timer;
+static void POLL_step(void *unused);
+#else
+void IRQ_28(void) __attribute__((alias("IRQ_STEP_changed"))); /* TMR2 */
+#endif
+
 /* EXTI IRQs. */
 void IRQ_6(void) __attribute__((alias("IRQ_SELA_changed"))); /* EXTI0 */
 void IRQ_7(void) __attribute__((alias("IRQ_WGATE_rotary"))); /* EXTI1 */
 void IRQ_10(void) __attribute__((alias("IRQ_SIDE_changed"))); /* EXTI4 */
 void IRQ_23(void) __attribute__((alias("IRQ_WGATE_rotary"))); /* EXTI9_5 */
-void IRQ_28(void) __attribute__((alias("IRQ_STEP_changed"))); /* TMR2 */
 void IRQ_40(void) __attribute__((alias("IRQ_MOTOR_CHGRST_rotary"))); /* EXTI15_10 */
+#if WDATA_TOGGLE
+void IRQ_27(void) __attribute__((alias("IRQ_wdata_capture"))); /* TMR1_CC */
+#endif
 #define MOTOR_CHGRST_IRQ 40
 static const struct exti_irq exti_irqs[] = {
+#if WDATA_TOGGLE
+    /* WDATA */ { 27, FLOPPY_IRQ_WGATE_PRI, 0 },
+#endif
     /* SELA */ {  6, FLOPPY_IRQ_SEL_PRI, 0 }, 
+#if !defined(APPLE2)
     /* STEP */ { 28, FLOPPY_IRQ_STEP_PRI, m(2) /* dummy */ },
+#endif
     /* WGATE */ {  7, FLOPPY_IRQ_WGATE_PRI, 0 },
     /* SIDE */ { 10, TIMER_IRQ_PRI, 0 }, 
     /* WGATE */ { 23, FLOPPY_IRQ_WGATE_PRI, 0 },
@@ -80,6 +107,7 @@ static volatile uint32_t *p_dma_rd_active;
 
 bool_t floppy_ribbon_is_reversed(void)
 {
+#if !defined(APPLE2)
     time_t t_start = time_now();
 
     /* If ribbon is reversed then most/all inputs are grounded. 
@@ -91,6 +119,7 @@ bool_t floppy_ribbon_is_reversed(void)
         if (time_since(t_start) > time_ms(1000))
             return TRUE;
     }
+#endif
 
     return FALSE;
 }
@@ -111,7 +140,9 @@ static void board_floppy_init(void)
     gpio->crl = (gpio->crl & ~(0xfu<<((pin)<<2)))       \
         | (((mode)&0xfu)<<((pin)<<2))
 
+#if !defined(APPLE2)
     gpio_configure_pin(gpioa, pin_step, GPI_bus);
+#endif
     gpio_configure_pin(gpio_data, pin_wdata, GPI_bus);
     gpio_configure_pin(gpio_data, pin_rdata, GPO_bus);
 
@@ -122,8 +153,10 @@ static void board_floppy_init(void)
         | (((mode)&0x3u)<<((pin)<<1));
 #define afio syscfg
 
+#if !defined(APPLE2)
     gpio_set_af(gpioa, pin_step, 1);
     gpio_configure_pin(gpioa, pin_step, AFI(PUPD_none));
+#endif
 
     gpio_set_af(gpio_data, pin_wdata, 1);
     gpio_configure_pin(gpio_data, pin_wdata, AFI(PUPD_none));
@@ -149,7 +182,16 @@ static void board_floppy_init(void)
         pin_wgate = 1; /* PB1 */
     }
 
+#if defined(APPLE2)
+    gpio_configure_pin(gpioa, pin_pha0,  GPI_bus);
+    gpio_configure_pin(gpioa, pin_pha1,  GPI_bus);
+    gpio_configure_pin(gpiob, pin_pha2,  GPI_bus);
+    gpio_configure_pin(gpioa, pin_pha3,  GPI_bus);
+    timer_init(&step_timer, POLL_step, NULL);
+    timer_set(&step_timer, time_now());
+#else
     gpio_configure_pin(gpiob, pin_dir,   GPI_bus);
+#endif
     gpio_configure_pin(gpioa, pin_sel0,  GPI_bus);
     gpio_configure_pin(gpiob, pin_wgate, GPI_bus);
     gpio_configure_pin(gpiob, pin_side,  GPI_bus);
@@ -275,6 +317,76 @@ static void update_SELA_irq(bool_t amiga_hd_id)
 #undef OFF
 }
 
+#if defined(APPLE2)
+
+static void POLL_step(void *unused)
+{
+    static unsigned int _pha;
+
+    struct drive *drv = &drive;
+    uint16_t idr_a, idr_b;
+    unsigned int pha;
+
+    /* Latch inputs. */
+    idr_a = gpioa->idr;
+    idr_b = gpiob->idr;
+
+    /* Bail if drive not selected. */
+    if (idr_a & m(pin_sel0)) {
+        _pha = 0;
+        goto out;
+    }
+
+    /* Debounce the phase signals. */
+    pha = _pha;
+    _pha = ((idr_a >> pin_pha0) & 1)
+        | ((idr_a >> (pin_pha1-1)) & 2)
+        | ((idr_b << (2-pin_pha2)) & 4)
+        | ((idr_a << (3-pin_pha3)) & 8);
+    pha &= _pha;
+
+    /* Do nothing while we're mid-step. */
+    if (drv->step.state & STEP_active)
+        goto out;
+
+    /* Rotate the phase bitmap so that the current phase is at bit 0. Note 
+     * that the current phase is directly related to the current cylinder. */
+    pha = ((pha | (pha << 4)) >> (drv->cyl & 3)) & 0xf;
+
+    /* Conditions to action a head step:
+     *  (1) Only one phase is asserted;
+     *  (2) That phase is adjacent to the current phase;
+     *  (3) We haven't hit a cylinder hard limit. */
+    switch (pha) {
+    case m(1): /* Phase +1 only */
+        if (drv->cyl == ff_cfg.max_cyl)
+            goto out;
+        drv->step.inward = TRUE;
+        break;
+    case m(3): /* Phase -1 only */
+        if (drv->cyl == 0)
+            goto out;
+        drv->step.inward = FALSE;
+        break;
+    default:
+        goto out;
+    }
+
+    /* Action a head step. */
+    if (dma_rd != NULL)
+        rdata_stop();
+    if (dma_wr != NULL)
+        wdata_stop();
+    drv->step.start = time_now();
+    drv->step.state = STEP_started;
+    IRQx_set_pending(FLOPPY_SOFTIRQ);
+
+out:
+    timer_set(&step_timer, step_timer.deadline + time_ms(1));
+}
+
+#else
+
 static bool_t drive_is_writing(void)
 {
     if (!dma_wr)
@@ -335,6 +447,8 @@ static void IRQ_STEP_changed(void)
     IRQx_set_pending(FLOPPY_SOFTIRQ);
 }
 
+#endif
+
 static void IRQ_SIDE_changed(void)
 {
     stk_time_t t = stk_now();
@@ -431,6 +545,17 @@ static void IRQ_CHGRST(struct drive *drv)
     }
 }
 
+#if WDATA_TOGGLE
+static void IRQ_wdata_capture(void)
+{
+    /* Clear WDATA-captured flag. */
+    (void)tim_wdata->ccr1;
+
+    /* Toggle polarity to capture the next edge. */
+    tim_wdata->ccer ^= TIM_CCER_CC1P;
+}
+#endif
+
 static void IRQ_MOTOR_CHGRST_rotary(void)
 {
     struct drive *drv = &drive;