pyfastservo: fix dac init script and cleanup

fast-servo/pyfastservo/dac.py

@@ -17,8 +17,7 @@
 # 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 time
-import os
 
 import spidev
 from pyfastservo.common import (
@@ -29,108 +28,58 @@ from pyfastservo.common import (
     CTRL_ADDR,
     MAP_MASK,
     PAGESIZE,
+    write_to_memory,
+    read_from_memory
 )
 
 # /dev/spidev2.0  <=> spidev<BUS>.<DEVICE>
 MAIN_DAC_BUS = 2
 MAIN_DAC_DEVICE = 0
-
 DAC_VERSION = 0x0A
 
 
-def main_dac_init():
+def spi_write(spi, address, value):
-    spi = spidev.SpiDev()
+    spi.xfer2([address, value])
 
-    try:
+def spi_read(spi, address):
-        spi.open(MAIN_DAC_BUS, MAIN_DAC_DEVICE)
+    rx_buffer = spi.xfer2([0x80 | address, 0x00])
-        spi.max_speed_hz = 5000
+    return rx_buffer[1]
-        spi.mode = 0b00  # CPOL = 0 CPHA = 0
-        spi.cshigh = False
 
-        spi_buffer = [0x00, 0x10]  # software reset
+def hard_reset(spi):
-        spi.xfer2(spi_buffer)
+    spi_write(spi, 0x00, 0x10)  # Software reset
+    spi_write(spi, 0x00, 0x00)  # Release software reset
+    spi_read(spi, 0x00)         # Read reset address (necessary for reset to take effect)
 
-        spi_buffer = [0x00, 0x00]  # release software reset
+def check_version(spi):
-        spi.xfer2(spi_buffer)
+    version = spi_read(spi, 0x1F)
+    print(f"DAC version: 0x{version:02X}")
+    return version == DAC_VERSION
 
-        spi_buffer = [
+def configure_dac(spi):
-            0x80,
+    power_down_reg = spi_read(spi, 0x01)
-            0x00,
+    spi_write(spi, 0x01, power_down_reg & ~(1 << 0))  # Clear EXTREF bit for internal reference
-        ]  # for some reason it is needed to read the reset address for reset to actually reset
+    spi_write(spi, 0x0D, 0x00)      # Set RREF to 10 kΩ for 1.0V reference
-        rx_buffer = spi.xfer2(spi_buffer)
+    spi_write(spi, 0x04, 0xA0)      # Enable on-chip IRSET (1.6 kΩ for 20mA output)
+    spi_write(spi, 0x07, 0xA0)      # Enable on-chip QRSET (1.6 kΩ for 20mA output)
+    spi_write(spi, 0x05, 0x00)      # Disable internal IRCML
+    spi_write(spi, 0x08, 0x00)      # Disable internal QRCML
+    spi_write(spi, 0x02, 0xB4)      # Enable 2's complement, LVDS interface, 4 LVDS lanes
 
-        spi_buffer = [0x9F, 0x00]  # hardware version
+def dac_self_calibration(spi):
-        rx_buffer = spi.xfer2(spi_buffer)
+    spi_write(spi, 0x12, 0x00)      # Reset calibration status
-        if rx_buffer[1] != DAC_VERSION:
+    spi_write(spi, 0x0E, 0x08)      # Enable calibration clock, default divide ratio
-            print(f"Unrecognized device: 0x{rx_buffer[1]:02X}")
+    spi_write(spi, 0x0E, 0x38)      # CALSELI = 1, CALSELQ = 1, CALCLK = 1
+    spi_write(spi, 0x12, 0x10)      # Set CALEN bit
 
-        print("=== Contents of spi buffer after DAC VERSION read back: ===")
+    while True:
-        print(f"0x{rx_buffer[0]:02X}{rx_buffer[1]:02X}")
+        status = spi_read(spi, 0x0F)
-
+        if status & 0xC0 == 0xC0:   # Both CALSTATI and CALSTATQ are 1
-        spi_buffer = [0x82, 00]
+            break
-        rx_buffer = spi.xfer2(spi_buffer)
+        time.sleep(0.01)
-        print(f"0x{rx_buffer[0]:02X}{rx_buffer[1]:02X}")
-
-        # set to 2's complement and I to be first of pair on data input pads
-        spi_buffer = [0x02, 0xB4]
-        rx_buffer = spi.xfer2(spi_buffer)
-        spi_buffer = [0x82, 00]
-        rx_buffer = spi.xfer2(spi_buffer)
-        print(f"0x{rx_buffer[0]:02X}{rx_buffer[1]:02X}")
-
-        for i in range(10):
-            spi_buffer = [0x94, 0x00]
-            rx_buffer = spi.xfer2(spi_buffer)
-            print(f"0x{rx_buffer[0]:02X}{rx_buffer[1]:02X}")
-
-    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]
-    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
-            mem[start_addr:stop_addr] = value_bytes
-            contents = mem[start_addr:stop_addr]
-    finally:
-        os.close(f)
 
+    spi_write(spi, 0x12, 0x00)      # Clear calibration bits
+    spi_write(spi, 0x0E, 0x30)      # Keep CALSELI and CALSELQ set, clear CALCLK
+    print("DAC self-calibration completed")
 
 def manual_override(enable=True):
     reg_contents = read_from_memory(CTRL_ADDR, 1)[0]
@@ -138,7 +87,6 @@ def manual_override(enable=True):
     to_write = reg_contents | 0b1 if enable else reg_contents & 0b110
     write_to_memory(CTRL_ADDR, to_write)
 
-
 def power_down(channel, power_down=True):
     assert channel in (0, 1)
 
@@ -152,31 +100,49 @@ def power_down(channel, power_down=True):
     reg_contents = read_from_memory(CTRL_ADDR, 1)[0]
     print(f"REG contents: 0b{reg_contents:03b}")
 
+def set_dac_output(value):
+    value = min(value, 0x3FFF)
+    low_word = value & 0xFF
+    high_word = (value >> 8) & 0x3F
 
-def write_sample(channel, sample):
+    write_to_memory(CH0_HIGH_WORD_ADDR, high_word)
-    assert channel in (0, 1)
+    write_to_memory(CH0_LOW_WORD_ADDR, low_word)
-    if channel == 0:
+    write_to_memory(CH1_HIGH_WORD_ADDR, high_word)
-        addresses = [CH0_HIGH_WORD_ADDR, CH0_LOW_WORD_ADDR]
+    write_to_memory(CH1_LOW_WORD_ADDR, low_word)
-    else:
+    print(f"DAC output set to: 0x{value:04X}")
-        addresses = [CH1_HIGH_WORD_ADDR, CH1_LOW_WORD_ADDR]
 
-    low_word_value = sample & 0xFF
+def configure_ad9117():
-    high_word_value = (sample >> 8) & 0x3F
+    spi = spidev.SpiDev()
-    values = [high_word_value, low_word_value]
+    spi.open(MAIN_DAC_BUS, MAIN_DAC_DEVICE)
-    for addr, value in zip(addresses, values):
+    spi.max_speed_hz = 5000
-        write_to_memory(addr, value)
+    spi.mode = 0b00  # CPOL = 0 CPHA = 0
+    spi.cshigh = False
 
+    try:
+        hard_reset(spi)
+        if not check_version(spi):
+            print("Unrecognized DAC version")
+            return False
 
-def write_ramp():
+        configure_dac(spi)
-    signal = [i for i in range(16384)]
+        dac_self_calibration(spi)
 
-    for value in signal:
-        write_sample(0, value)
-
-def main():
-    main_dac_init()
         power_down(0, False)
         power_down(1, False)
+        manual_override(True)
+
+        # Enable DAC outputs
+        spi_write(spi, 0x01, spi_read(spi, 0x01) & ~((1 << 4) | (1 << 3)))
+
+        print("AD9117 configuration completed successfully")
+        return True
+
+    except Exception as e:
+        print(f"Error configuring AD9117: {e}")
+        return False
+
+    finally:
+        spi.close()
 
 if __name__ == "__main__":
-    main()
+    configure_ad9117()