mpm/mpmd: Expose APIs to drive GPIO sources

The N310 has a feature that allows the front panel GPIOs to be driven by
various sources: The PS, or any of the radio channels. The MPM-based
APIs did not expose any way to change that.

Changes:
- Add MPM APIs to PeripheralManagerBase and n3xx classes
- Improve comments and explanations
- Add host-side hooks into these new APIs in mpmd_mb_controller
- Implement these APIs for N3xx

The N3xx devices will have the option to set the GPIO source to "PS", or
to one of "RF0", "RF1", "RF2", "RF3" (if there are four channels; the
N300 and N320 can only go up to RF1).

Note: The N310 radio does not have separate FP-GPIO banks for channels
0 and 1, which needs to be fixed in a separate commit.

1 files changed, 7 insertions, 6 deletions

diff --git a/mpm/python/n3xx_bist b/mpm/python/n3xx_bist
index a8bda66f5..1202fe121 100755
--- a/mpm/python/n3xx_bist
+++ b/mpm/python/n3xx_bist
@@ -472,8 +472,8 @@ class N3XXBIST(bist.UsrpBIST):
         - read_patterns: A list of patterns that were read back
         """
         assert 'gpio' in self.tests_to_run
-        # patterns = list(range(64))
-        GPIO_WIDTH = 12
+        # Our FP-GPIO has 12 programmable pins
+        gpio_width = 12
         patterns = range(64)
         if self.args.dry_run:
             return True, {
@@ -484,16 +484,17 @@ class N3XXBIST(bist.UsrpBIST):
         gpio_tca6424 = n3xx_periphs.TCA6424(self.mb_rev)
         gpio_tca6424.set("FPGA-GPIO-EN")
         mb_regs = n3xx_periphs.MboardRegsControl(n3xx.n3xx.mboard_regs_label, self.log)
+        # We set all 12 pins to be driven by the PS
         mb_regs.set_fp_gpio_master(0xFFF)
         # Allow some time for the front-panel GPIOs to become usable
         time.sleep(.5)
-        ddr1 = 0x03f
-        ddr2 = 0xfc0
+        ddr1 = 0x03f # Lower 6 pins are outputs
+        ddr2 = 0xfc0 # Upper 6 pins are inputs
         def _run_gpio(ddr, patterns):
             " Run a GPIO test for a given set of patterns "
             gpio_ctrl = n3xx_periphs.FrontpanelGPIO(ddr)
             for pattern in patterns:
-                bist.gpio_set_all(gpio_ctrl, pattern, GPIO_WIDTH, ddr)
+                bist.gpio_set_all(gpio_ctrl, pattern, gpio_width, ddr)
                 time.sleep(0.1)
                 gpio_rb = gpio_ctrl.get_all()
                 if  pattern != gpio_rb:
@@ -502,7 +503,7 @@ class N3XXBIST(bist.UsrpBIST):
             return True, {'write_patterns': list(patterns),
                           'read_patterns': list(patterns)}
         status, data = _run_gpio(ddr1, patterns)
-        if  not status:
+        if not status:
             return status, data
         status, data = _run_gpio(ddr2, patterns)
         return status, data