# ---  gpio_sio.py - 088.09.2022
#

def gpio_info(pin, show_regs = True):
    # Liefert zu dem gewählten Pin die Information zu:
    # - input oder output, high oder low
    # - Pullups, funcsel
    # show_regs: zeigt zusätzlich die Registerinhalte an
    status   = _gpio_status_reg(pin)
    ctrl     = _gpio_ctrl_reg(pin)
    pad_ctrl = _gpio_pad_ctrl_reg(pin)

    print(f"\nPin '{pin:2}' is - ", end = "")
    
    if status & 0x3000:
        print("Output: ", end = "")
        if status & 0x300:
            print("high", end = "")
        else:
            print("low ", end = "")
    else:
        print("Input : ", end = "")
        if status & 0x000E_0000:
            print("high", end = "")
        else:
            print("low ", end = "")
            
    print(", Pull_Up: ", end = "")
    if pad_ctrl & 0x08:
        print("enabled ", end = "")
    else:
        print("disabled", end = "")
    print(", Pull_Down: ", end = "")
    if pad_ctrl & 0x04:
        print("enabled ", end = "")
    else:
        print("disabled", end = "")
            
    print(f", FUNCSEL: 0x{ctrl & 0x1F:02X}")
    if show_regs:
        print("Pin_Status  - Pin_Ctrl    - Pad_Ctrl")
        print(f"0x{status:08x}  - 0x{ctrl:08x}  - 0b{pad_ctrl:08b}")

@micropython.asm_thumb
# Status-Register = IO_BASE + 8 * pin + offset 0
# _gpio_status_reg(pin)
def _gpio_status_reg(r0):
    # Liefert für den gewählten Pin den Inhalt des Status Registers zurück
    align(4)
    mov(r7, pc)         # r7 = star_adr of data
    b(START)
    data(2, 0x4000, 0x4001)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = IO_BASE
    mov(r3, 8)          # pin offset
    mul(r3, r0)         # offset * pin
    add(r7, r7, r3)
    ldr(r0, [r7, 0])    # register offset 0

@micropython.asm_thumb
# Ctrl-Register - IO_BASE + 8 * pin + offset 4
# _gpio_ctrl_reg(pin)
def _gpio_ctrl_reg(r0):
    # Liefert für den gewählten Pin den Inhalt des Ctrl-Registers zurück
    align(4)
    mov(r7, pc)         # r7 = star_adr of data
    b(START)
    data(2, 0x4000, 0x4001)
    
    label(START)   
    ldr(r7, [r7, 0])    # r7 = IO_BASE
    mov(r3, 8)          # pin offset
    mul(r3, r0)         # offset * pin
    add(r7, r7, r3)
    ldr(r0, [r7, 4])    # ctrl-register offset 4

@micropython.asm_thumb
# Pad-Ctrl-Register = PAD_BASE + 4 * pin + offset 4
# _gpio_pad_ctrl_reg(pin)
def _gpio_pad_ctrl_reg(r0):
    # Liefert für den gewählten Pin den Inhalt des pad-ctrl-Registers zurück
    align(4)
    mov(r7, pc)         # r7 = star_adr of data
    b(START)
    data(2, 0xC000, 0x4001)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = PAD_BASE
    mov(r3, 4)          # pin offset
    mul(r3, r0)         # offset * pin
    add(r7, r7, r3)     # pin adr
    ldrb(r0, [r7, 4])   # byte offset 4

@micropython.asm_thumb
# Pad-Ctrl-Register = PAD_BASE + 4 * pin + offset 4
# gpio_pulls(pin, 0|1)
def gpio_pulls(r0, r1):
    # Setzt für den gewähtlen Pin Pullup | Pulldown
    align(4)
    mov(r7, pc)         # r7 = star_adr of data
    b(START)
    data(2, 0xC000, 0x4001) 

    label(START)                       
    ldr(r7, [r7, 0])    # r7 = PAD_BASE
                        # r1 -> 0 = PULLDOWN, > 0 = PULLUP
    mov(r3, 4)          # pin offset
    mul(r3, r0)         # offset * pin
    add(r7, r7, r3)     # pin adr
    ldrb(r3, [r7, 4])   # byte offset 4
    mov(r4, 0b1111_0011)# maskout pullup + pulldown bit
    and_(r3, r4)
    cmp(r1, 0)
    beq(PULLDOWN)
    mov(r4, 0b0000_1000)# pullup
    b(NEXT)
    
    label(PULLDOWN)
    mov(r4, 0b0000_0100)# puLLDOWN = default
    
    label(NEXT)
    orr(r3, r4)
    strb(r3, [r7, 4])
    
@micropython.asm_thumb
# Ctrl-Register - IO_BASE + 8 * pin + offset 4
# gpio_init(pin, funcsel)
def gpio_init(r0, r1):
    # Setzt dengewählten Pin als input mit funcsel = r1
    align(4)
    mov(r7, pc)         # r7 = star_adr of data
    b(START)
    data(2, 0x4000, 0x4001)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = IO_BASE
    mov(r3, 8)          # pin offset
    mul(r3, r0)         # offset * pin
    add(r7, r7, r3)
    str(r1, [r7, 4])    # FUNCSEL r1
    

# --- SIO -- GPIO_IN -----------------------------------------
@micropython.asm_thumb
# gpio_in()
def gpio_in():
    # Gibt den Input-Status aller Pins zurück
    align(4)
    mov(r7, pc)         # r7 = star_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    ldr(r0, [r7, 0x04])   


@micropython.asm_thumb
# gpio_in_pin(Pin_Nr)
def gpio_in_pin(r0):
    # Gibt den Input-Status eines einzigen Input-Pins zurück
    align(4)
    mov(r7, pc)         # r7 = star_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    ldr(r1, [r7, 0x04])
    lsr(r1, r0)

    mov(r2, 1)
    and_(r1, r2)
    mov(r0, r1)

# --- SIO -- GPIO_OUT ----------------------------------------
@micropython.asm_thumb
# gpio_out(mask)
def gpio_out(r0):
    # Setzt die Output-Pins auf den Wert der Maske
    align(4)
    mov(r7, pc)         # r7 = start_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    str(r0, [r7, 0x10])  

@micropython.asm_thumb
# gpio_out_set(mask)
def gpio_out_set(r0):
    # Setzt die Output-Pins der Maske auf High
    align(4)
    mov(r7, pc)         # r7 = start_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    str(r0, [r7, 0x14])   

@micropython.asm_thumb
# gpio_out_clr(mask)
def gpio_out_clr(r0):
    # Setzt die Output-Pins der Maske auf LOW
    align(4)
    mov(r7, pc)         # r7 = start_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    str(r0, [r7, 0x18])   

@micropython.asm_thumb
# gpio_out_xor(mask)
def gpio_out_xor(r0):
    # Toggled die maskierten Output-Pins
    align(4)
    mov(r7, pc)         # r7 = start_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    str(r0, [r7, 0x1C])   

# --- SIO -- GPIO_OE ----------------------------------------
@micropython.asm_thumb
# gpio_oe(mask)
def gpio_oe(r0):
    # Output Enable: Konfiguriert die gesetzten Pins als Output
    #                die nicht gestzten Pins als Input 
    align(4)
    mov(r7, pc)         # r7 = start_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    str(r0, [r7, 0x20])    

@micropython.asm_thumb
# gpio_oe_set(mask)
def gpio_oe_set(r0):
    # Output Enable: Konfiguriert die gesetzten Pins als Output
    align(4)
    mov(r7, pc)         # r7 = start_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    str(r0, [r7, 0x24])  

@micropython.asm_thumb
# gpio_oe_set(mask)
def gpio_oe_clr(r0):
    # Output Enable: Konfiguriert die gesetzten Pins als Imput
    align(4)
    mov(r7, pc)         # r7 = start_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    str(r0, [r7, 0x28])  

@micropython.asm_thumb
# gpio_oe_set(mask)
def gpio_oe_xor(r0):
    # Output Enable: toggled die Output-Dir der gesetzten Pins
    align(4)
    mov(r7, pc)         # r7 = start_adr of data
    b(START)
    data(2, 0x0000, 0xD000)
    
    label(START)                       
    ldr(r7, [r7, 0])    # r7 = SIO_BASE

    str(r0, [r7, 0x2C])  

# -----------------------------------------------
if __name__ == "__main__":
    import time
    # """
    # Pin 25 = onboard LED
    
    gpio_init(25, 5)        # FUNCSEL = 5
    gpio_pulls(25, 0)       # default Pullup low
    gpio_oe_set(1<<25)      # Output
    gpio_out_clr(1<<25)     # low
    
    gpio_info(25)
       
    for i in range(20):
        time.sleep(.3)
        gpio_out_xor(1<<25)
    gpio_info(25)
    
    gpio_oe_clr(1<<25)    # input
    gpio_pulls(25, 1)     # Pullup nach High

    gpio_info(25)

    print(f"\ngpio_in: {gpio_in():032b}")
    print(f"Pin 25 is *{gpio_in_pin(25)}'")
    
    # gpio_info(26)
    
    # """
    
    """
    for i in range(5):
        gpio_init(i, 5)     # funcsel 5
    
    gpio_oe_set(0x0F)
    mask = 1
    for _ in range(50):
        gpio_out(mask)
        mask <<= 1
        mask &= 0x1F
        if mask == 0:
            mask = 1
        time.sleep(.2)
    """