SPI opens wrong spidev path

[pdp7]

System info:

current Adafruit_BBIO master on Debian 9.2 image with 4.14.2-ti-r13 kernel

Example:

from Adafruit_BBIO.SPI import SPI

print("SPI(1,0)")
spi = SPI(1,0)
print(spi.xfer2([32, 11, 110, 22, 220]))
spi.close() 

print("SPI(1,1)");
spi = SPI(1,1)
print(spi.xfer2([32, 11, 110, 22, 220]))
spi.close() 

print("SPI(2,0)")
spi = SPI(2,0)
print(spi.xfer2([32, 11, 110, 22, 220]))
spi.close() 

print("SPI(2,1)");
spi = SPI(2,1)
print(spi.xfer2([32, 11, 110, 22, 220]))
spi.close() 

Issue:

• SPI(1,0) and SPI(2,0) both open /dev/spidev1.0
• SPI(1,1) and SPI(2,1) both open /dev/spidev1.1
• However, the actual spidev devices that exist are:
  • /dev/spidev0.0
  • /dev/spidev0.1
  • /dev/spidev1.0
  • /dev/spidev1.1
• These are the /sys/ entries:

/sys/devices/platform/ocp/48030000.spi/spi_master/spi0/spi0.0/spidev/spidev0.0/dev
/sys/devices/platform/ocp/48030000.spi/spi_master/spi0/spi0.1/spidev/spidev0.1/dev
/sys/devices/platform/ocp/481a0000.spi/spi_master/spi1/spi1.0/spidev/spidev1.0/dev
/sys/devices/platform/ocp/481a0000.spi/spi_master/spi1/spi1.1/spidev/spidev1.1/dev

[pdp7]

patch eliminates call to get_spi_bus_path_number() as it is unnecessary:

index 5b1f6ad..c761c0a 100644
--- a/source/spimodule.c
+++ b/source/spimodule.c
@@ -32,6 +32,7 @@
 #include <linux/types.h>
 #include <sys/ioctl.h>
 #include "common.h"
+#include "c_pinmux.h"
 
 #if PY_MAJOR_VERSION < 3
 #      define PyLong_AS_LONG(val) PyInt_AS_LONG(val)
@@ -703,7 +704,6 @@ static PyObject *
 SPI_open(SPI *self, PyObject *args, PyObject *kwds)
 {
        int bus, device;
-       int bus_path;
        int max_dt_length = 15;
        char device_tree_name[max_dt_length];
        char path[MAXPATH];
@@ -722,18 +722,14 @@ SPI_open(SPI *self, PyObject *args, PyObject *kwds)
                return NULL;
        }
 
-       bus_path = get_spi_bus_path_number(bus);
-       if (bus_path == -1) {
-               PyErr_SetString(PyExc_OverflowError,
-                       "Unable to find loaded spi bus path.");
-               return NULL;
-       }
-
-       if (snprintf(path, MAXPATH, "/dev/spidev%d.%d", bus_path, device) >= MAXPATH) {
+       fprintf(stderr, "bus=%d\n", bus);
+       fprintf(stderr, "device=%d\n", device);
+       if (snprintf(path, MAXPATH, "/dev/spidev%d.%d", bus, device) >= MAXPATH) {
                PyErr_SetString(PyExc_OverflowError,
                        "Bus and/or device number is invalid.");
                return NULL;
        }
+       fprintf(stderr, "path=%s\n", path);
        if ((self->fd = open(path, O_RDWR, 0)) == -1) {
                PyErr_SetFromErrno(PyExc_IOError);
                return NULL;

results:

SPI(0,0)
================================
bus=0
device=0
path=/dev/spidev0.0
[255, 255, 255, 255, 255]

SPI(0,1)
================================
bus=0
device=1
path=/dev/spidev0.1
[255, 255, 255, 255, 255]

SPI(1,0)
================================
bus=1
device=0
path=/dev/spidev1.0
[255, 255, 255, 255, 255]

SPI(1,1)
================================
bus=1
device=1
path=/dev/spidev1.1
[255, 255, 255, 255, 255]

SPI(2,0)
================================
bus=2
device=0
path=/dev/spidev2.0
Traceback (most recent call last):
  File "/home/debian/spi.py", line 32, in <module>
    spi = SPI(2,0)
IOError: [Errno 2] No such file or directory