pyfastservo: fix adc init script and cleanup

fast-servo/pyfastservo/adc.py

@@ -17,8 +17,6 @@
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-import mmap
-import os
 
 import spidev
 from pyfastservo.common import (
@@ -33,6 +31,8 @@ from pyfastservo.common import (
     AUX_ADC_ADDR,
     MAP_MASK,
     PAGESIZE,
+    write_to_memory,
+    read_from_memory
 )
 
 # /dev/spidev1.0  <=> spidev<BUS>.<DEVICE>
@@ -44,276 +44,118 @@ AUX_ADC_PORT_A = 2
 AUX_ADC_PORT_B = 3
 
 
-def main_adc_config(test_pattern):
+def spi_write(spi, address, value):
+    spi.xfer2([address, value])
+
+def spi_read(spi, address):
+    rx_buffer = spi.xfer2([0x80 | address, 0x00])
+    return rx_buffer[1]
+
+def main_adc_config(spi, test_pattern):
     high_word = (test_pattern & 0xFF00) >> 8
     low_word = test_pattern & 0xFF
 
-    spi = spidev.SpiDev()
+    spi_write(spi, 0x00, 0x80)              # reset
+    spi_write(spi, 0x01, 0x20)              # REGISTER A1: set to Two's complement Data Format
+    spi_write(spi, 0x02, 0x15)              # REGISTER A2: set to LVDS output, set 4 data lanes and turn on test mode
+    spi_write(spi, 0x03, high_word)         # REGISTER A3: test pattern high word
+    spi_write(spi, 0x04, low_word)          # REGISTER A4: test pattern low word
 
-    try:
+def main_adc_test_mode(spi, enable):
-        spi.open(MAIN_ADC_BUS, MAIN_ADC_DEVICE)
+    reg_contents = 0x15 if enable else 0x11 # set to LVDS output, set 4 data lanes and turn on or off test mode
-        spi.max_speed_hz = 50000
+    spi_write(spi, 0x02, reg_contents)
-        spi.mode = 0b00  # CPOL = 0 CPHA = 0
-        spi.cshigh = False
-        # spi.read0 = False
 
-        spi_buffer = [0x00, 0x80]  # reset
+def verify_adc_registers(spi, reg_to_check):
-        rx_buffer = [0x00, 0x00]
+    for register, expected_value in reg_to_check.items():
+        value = spi_read(spi, register)
+        print(f"Spi readback register 0x{register:02x}: 0x{value:02x}")
+        if value != expected_value:
+            print(f"Different value read than sent in reg 0x{register:02x}")
 
-        spi.xfer2(spi_buffer)
+def read_frame():
-
+    return read_from_memory(ADC_FRAME_ADDR, 1)[0]
-        # REGISTER A1
-        spi_buffer = [0x01, 0x20]  # set to Two's complement Data Format
-        spi.xfer2(spi_buffer)
-
-        # read values back
-        spi_buffer = [0x81, 0x00]
-        rx_buffer = spi.xfer2(spi_buffer)
-        print(f"Spi readback register 0x01: 0x{rx_buffer[1]:02x}")
-        if rx_buffer[1] != 0x20:
-            print("Different value read than sent in reg 0x02")
-
-        # REGISTER A2
-        spi_buffer = [
-            0x02,
-            0x15,
-        ]  # set to LVDS output, set 4 data lanes and turn on test mode
-        spi.xfer2(spi_buffer)
-
-        # read values back
-        spi_buffer = [0x82, 0x00]
-        rx_buffer = spi.xfer2(spi_buffer)
-        print(f"Spi readback register 0x02: 0x{rx_buffer[1]:02x}")
-        if rx_buffer[1] != 0x15:
-            print("Different value read than sent in reg 0x02")
-
-        # REGISTER A3
-        # test pattern high word
-        spi_buffer = [0x03, high_word]
-        spi.xfer2(spi_buffer)
-
-        # read balues back
-        spi_buffer = [0x83, 0x00]
-        rx_buffer = spi.xfer2(spi_buffer)
-        print(f"Spi readback register 0x03: 0x{rx_buffer[1]:02x}")
-        if rx_buffer[1] != high_word:
-            print("Different value read than sent in reg 0x03")
-
-        # REGISTER A4
-        # test pattern low word
-        spi_buffer = [0x04, low_word]
-        spi.xfer2(spi_buffer)
-
-        # read balues back
-        spi_buffer = [0x84, 0x00]
-        rx_buffer = spi.xfer2(spi_buffer)
-        print(f"Spi readback register 0x04: 0x{rx_buffer[1]:02x}")
-        if rx_buffer[1] != low_word:
-            print("Different value read than sent in reg 0x04")
-    finally:
-        spi.close()
-
-
-def main_adc_test_mode(enable):
-    spi = spidev.SpiDev()
-
-    try:
-        spi.open(MAIN_ADC_BUS, MAIN_ADC_DEVICE)
-        spi.max_speed_hz = 50000
-        spi.mode = 0b00  # CPOL = 0 CPHA = 0
-        spi.cshigh = False
-        # spi.read0 = True
-
-        reg_contents = (
-            0x15 if enable else 0x11
-        )  # set to LVDS output, set 4 data lanes and turn on or off test mode
-        spi_buffer = [0x02, reg_contents]
-        spi.xfer2(spi_buffer)
-
-        # read values back
-        spi_buffer = [0x82, 0x00]
-        rx_buffer = spi.xfer2(spi_buffer)
-        print(f"Spi readback register 0x02: 0x{rx_buffer[1]:02x}")
-        if rx_buffer[1] != reg_contents:
-            print("Different value read than sent in reg 0x02")
-    finally:
-        spi.close()
-
-
-def read_from_memory(address, n_bytes):
-    assert n_bytes <= 4
-    addr = address
-
-    try:
-        f = os.open("/dev/mem", os.O_SYNC | os.O_RDWR)
-        with mmap.mmap(
-            f,
-            PAGESIZE,
-            mmap.MAP_SHARED,
-            mmap.PROT_READ | mmap.PROT_WRITE,
-            offset=addr & ~MAP_MASK,
-        ) as mem:
-            start_addr = addr & MAP_MASK
-            stop_addr = start_addr + 4
-            # print(f"addr: 0x{addr:x}\tstart_addr: 0x{start_addr}\tstop_addr: 0x{stop_addr}")
-            contents = mem[start_addr:stop_addr]
-            read_value = list(contents)[:n_bytes]
-            # print("Read value: ", read_value)
-    finally:
-        os.close(f)
-
-    return read_value
-
-
-def write_to_memory(address, value):
-    value_bytes = value.to_bytes(4, "little")
-    addr = address
-
-    try:
-        f = os.open("/dev/mem", os.O_SYNC | os.O_RDWR)
-        with mmap.mmap(
-            f,
-            PAGESIZE,
-            mmap.MAP_SHARED,
-            mmap.PROT_READ | mmap.PROT_WRITE,
-            offset=addr & ~MAP_MASK,
-        ) as mem:
-            start_addr = addr & MAP_MASK
-            stop_addr = start_addr + 4
-            # print(f"addr: 0x{addr:x}\tstart_addr: 0x{start_addr}\tstop_addr: 0x{stop_addr}")
-            mem[start_addr:stop_addr] = value_bytes
-            contents = mem[start_addr:stop_addr]
-            # print("Read value: ", list(contents), " written value: ", list(value_bytes))
-    finally:
-        os.close(f)
-
-
-def word_align():
-
-    value = 0
-    edge_detected = False
-    transition = False
-    tap_delay = 0
 
+def perform_bitslip():
     for i in range(4):
-        current_frame = read_from_memory(ADC_FRAME_ADDR, 1)[0]
+        current_frame = read_frame()
         if current_frame != 0x0C:
-            print(
+            print(f"Performing bitslip (iteration: {i}). Current frame: 0x{current_frame:02x}")
-                f"Performing bitslip (bitslip iteration: {i}). Reason: current_frame is 0x{current_frame:02x} instead of 0x0C"
-            )
             write_to_memory(ADC_BITSLIP_ADDR, 1)
         else:
-            print(f"No bitslip required; Currernt frame = 0x{current_frame:02x}")
+            print(f"No bitslip required; Current frame: 0x{current_frame:02x}")
-            break
+            return
 
-    current_frame = read_from_memory(ADC_FRAME_ADDR, 1)[0]
+def find_edge():
-    prev_frame = current_frame
+    prev_frame = read_frame()
-
+    transition = False
-    for i in range(32):
+    for tap_delay in range(32):
         write_to_memory(ADC_DELAY_ADDR, tap_delay)
-        if edge_detected == 1:
+        current_frame = read_frame()
-            break
-        current_frame = read_from_memory(ADC_FRAME_ADDR, 1)[0]
 
-        print(f"Tap delay: {tap_delay}")
+        print(f"Tap delay: {tap_delay}, Current frame: 0x{current_frame:02x}")
-        print(f"Current frame: 0x{current_frame:02x}")
 
-        if current_frame == prev_frame:
+        if current_frame != prev_frame:
-            tap_delay += 1
+            if not transition:
-        elif not transition:
-            tap_delay += 1
                 transition = True
-        elif transition:
+            else:
-            tap_delay = i // 2
+                final_delay = (tap_delay // 2) + 2
-            edge_detected = True
+                print(f"Edge detected; setting iDelay to: {final_delay}")
+                write_to_memory(ADC_DELAY_ADDR, final_delay)
+                return
 
         prev_frame = current_frame
 
-    if not edge_detected:
+    # If no edge detected
-        tap_delay = 11  # empirically tested to work best
+    final_delay = 11
-        write_to_memory(ADC_DELAY_ADDR, tap_delay)
+    print(f"No edge detected; setting iDelay to: {final_delay}")
-        print(f"No edge detected; setting iDelay to: {tap_delay}")
+    write_to_memory(ADC_DELAY_ADDR, final_delay)
-    if edge_detected:
-        write_to_memory(ADC_DELAY_ADDR, tap_delay + 2)
-        print(f"Edge detected; setting iDelay to (tap_delay + 2): {tap_delay} + 2")
 
-    adc_ch0 = read_from_memory(ADC_CH0_HIGH_ADDR, 4)
+def read_adc_channel(high_addr, low_addr):
-    print(f"ADC_CH0: 0x{adc_ch0}")
+    return (read_from_memory(high_addr, 1)[0] << 8) | read_from_memory(low_addr, 1)[0]
 
-    adc_ch0 = (read_from_memory(ADC_CH0_HIGH_ADDR, 1)[0] << 8) | read_from_memory(
+def print_adc_channels():
-        ADC_CH0_LOW_ADDR, 1
+    adc_ch0 = read_adc_channel(ADC_CH0_HIGH_ADDR, ADC_CH0_LOW_ADDR)
-    )[0]
+    adc_ch1 = read_adc_channel(ADC_CH1_HIGH_ADDR, ADC_CH1_LOW_ADDR)
-    adc_ch1 = (read_from_memory(ADC_CH1_HIGH_ADDR, 1)[0] << 8) | read_from_memory(
-        ADC_CH1_LOW_ADDR, 1
-    )[0]
     print(f"Final ADC_CH0: 0x{adc_ch0:04x}")
     print(f"Final ADC_CH1: 0x{adc_ch1:04x}")
 
+def enable_adc_afe(ch1_x10=False, ch2_x10=False):
+    ctrl_value = (ch2_x10 << 1) | ch1_x10
+    write_to_memory(ADC_AFE_CTRL_ADDR, ctrl_value)
+    afe_ctrl = read_from_memory(ADC_AFE_CTRL_ADDR, 1)[0]
+    print(f"ADC_AFE_CTRL: 0x{afe_ctrl:02X}")
+    return afe_ctrl
 
-def modify_bit(original_value, position, bit_value):
+def configure_ltc2195():
-    mask = 1 << position
-    return (original_value & ~mask) | (bit_value << position)
-
-
-def adc_aux_config():
-    # MSB to LSB
-    # | RANGE | ADDR [2:0] | DIFF |
-    #       DIFF = 0    =>  configure as single ended (it is negated in gateware)
-    #       RANGE = 0   =>  configure as 0-2.5 Vref
-    to_write = 0b00000
-    write_to_memory(AUX_ADC_ADDR, to_write)
-
-
-def adc_aux_read(port, type, pin):
-    # port:
-    #   1 - port A
-    #   2 - port B
-    # type:
-    #   0 - single-ended
-    #   1 - differential
-    # pin:
-    #   0b000   - VA1/VB1
-    #   0b001   - VA2/VB2
-    #   0b010   - VA3/VB3
-    #   0b011   - VA4/VB4
-
-    assert type in (0, 1)
-    assert port in (1, 2)
-
-    write_buffer = [0, 0]
-    read_buffer = [0, 0]
-
-    aux_config_reg = read_from_memory(AUX_ADC_ADDR, 1)[0]
-    aux_config = (aux_config_reg & 0b10001) | pin << 1
-    write_to_memory(AUX_ADC_ADDR, aux_config)
-
     spi = spidev.SpiDev()
     try:
-        spi.open(1, 3)  # AUX ADC 1?
+        spi.open(MAIN_ADC_BUS, MAIN_ADC_DEVICE)
-        spi.max_speed_hz = 5000
+        spi.max_speed_hz = 50000
-        spi.mode = 0b00
+        spi.mode = 0b00  # CPOL = 0 CPHA = 0
         spi.cshigh = False
 
-        read_buffer = spi.xfer2(write_buffer)
+        test_pattern = 0x811F
-        mu_voltage = read_buffer[0] << 8 | read_buffer[1] >> 2
+        main_adc_config(spi, test_pattern)
-        print(f"MU_voltage: 0x{mu_voltage:04X}")
+
-        print(f"Read_buffer[0]: 0x{read_buffer[0]:02X}")
+        verify_adc_registers(spi, {
-        print(f"Read_buffer[1]: 0x{read_buffer[1]:02X}")
+            0x01: 0x20,
-        return mu_voltage * 2.5 / 4096
+            0x02: 0x15,
+            0x03: (test_pattern & 0xFF00) >> 8,
+            0x04: test_pattern & 0xFF
+        })
+
+        # Performing Word Align
+        perform_bitslip()
+        find_edge()
+        print_adc_channels()
+
+        main_adc_test_mode(spi, False)
+        verify_adc_registers(spi, {0x02: 0x11})  # Verify test mode is off
+
+        enable_adc_afe()
 
     finally:
         spi.close()
 
-
-def main():
-    main_adc_config(0x811F)
-    word_align()
-
-    main_adc_test_mode(False)
-
-    write_to_memory(ADC_AFE_CTRL_ADDR, 0b1100) # {-, -, ch2_X10, ch1_X10}
-    print(read_from_memory(ADC_AFE_CTRL_ADDR, 1)[0])
-
-
 if __name__ == "__main__":
-    main()
+    configure_ltc2195()