PWM setup & diagnostics (#5)

This PR adds a library for controlling the am335x ehrpwm module. This is a work-in-progress, having demonstrated how to configure the basic settings and see a functional PWM output. This PR also demonstrates a failure to make PWM interrupt generation work for the PRU. Will post a forum question using this content. See comments in lib/pwm/am335x/pwm-am335x.c.
jmacd · Mar 3, 2024 · d352b8c · d352b8c
1 parent 61f8cc1
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diff --git a/.bazelrc b/.bazelrc
@@ -13,16 +13,17 @@ build --spawn_strategy=standalone
 build:pru0 --crosstool_top=//tools/toolchain:clpru_suite
 build:pru0 --cpu=pru
 build:pru0 --host_crosstool_top=@bazel_tools//tools/cpp:toolchain
-build:pru0 --platforms //tools/toolchain:real_pru
+build:pru0 --platforms //tools/toolchain:real_pru0
 build:pru0 --copt='-DSUPRUGLUE_AM335X'
-build:pru1 --copt='-DSUPRUGLUE_PRU_NUM=0'
+build:pru0 --copt='-DSUPRUGLUE_PRU_NUM=0'
 build:pru0 --copt='--opt_level=4'
 build:pru0 --copt='--opt_for_speed=0'
 
+
 build:pru1 --crosstool_top=//tools/toolchain:clpru_suite
 build:pru1 --cpu=pru
 build:pru1 --host_crosstool_top=@bazel_tools//tools/cpp:toolchain
-build:pru1 --platforms //tools/toolchain:real_pru
+build:pru1 --platforms //tools/toolchain:real_pru1
 build:pru1 --copt='-DSUPRUGLUE_AM335X'
 build:pru1 --copt='-DSUPRUGLUE_PRU_NUM=1'
 build:pru1 --copt='--opt_level=4'

diff --git a/.gitmodules b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "kernel/ti-linux-kernel-dev"]
+	path = kernel/ti-linux-kernel-dev
+	url = git@github.com:RobertCNelson/ti-linux-kernel-dev.git
diff --git a/README.md b/README.md
@@ -22,22 +22,17 @@ achieve success.
 In 2021, after nearly twenty years working for Big Tech companies I
 moved to the Mendocino coast and became the owner/operator of the
 Caspar, California community water system.  With a background in
-open-source software and specializing in telemetry systems, you
-guessed it--
-
-I'm writing Supruglue as the foundation for an open-source SCADA
-system.
+open-source software and specializing in telemetry systems, I'm
+writing Supruglue as the foundation for an open-source SCADA system.
 
 ### WORK IN PROGRESS
 
 This repository is under development.
 
 The next steps are:
 
-- Time support: timestamps, sleep & timer functions
 - Carveout support: setup regions for bulk data transfer
-- Interrupt controller logic
-- Drivers: eCAP, PWM, DMA, etc.
+- Drivers: i2c, eCAP, PWM, DMA, etc.
 - Multi-PRU coordination.
 
 Sample application goals:
@@ -70,15 +65,17 @@ To cross-compile for the Beaglebone ARM:
 bazel build --config=arm ...
 ```
 
-### Example
+### Examples
+
+#### Two LEDs
 
 The example will alternatingly flash two LEDs on pins `P9_23` and `P9_25`.
 
 ```
-bazel build --config=pru0 //examples:example_pru0
+bazel build --config=pru0 //examples/two_leds:example_pru0
 ```
 
-The firmware is located in `bazel-out/pru-fastbuild/bin/examples/example_pru0`
+The firmware is located in `bazel-out/pru-fastbuild/bin/examples/two_leds/example_pru0`
 
 To build the Supruglue command-line interface,
 

diff --git a/arch/ti-pruss-intr.csv b/arch/ti-pruss-intr.csv
@@ -14,7 +14,7 @@ Event Number,Signal Name,Source,MII RT Signal Name
 12,latch0_in,PRU-ICSS IEP,PRU-ICSS0 Internal Interrupts
 13,sync1_out_pend,PRU-ICSS IEP,PRU-ICSS0 Internal Interrupts
 14,sync0_out_pend,PRU-ICSS IEP,PRU-ICSS0 Internal Interrupts
-15,pr1_ecap_intr_req,PRU-ICSS eCAP,PRU-ICSS0 Internal Interrupts
+15,pr1_pru_ecap_intr_req,PRU-ICSS eCAP,PRU-ICSS0 Internal Interrupts
 16,pr1_pru_mst_intr[0]_intr_req,pru0 or pru1,PRU-ICSS0 Internal Interrupts
 17,pr1_pru_mst_intr[1]_intr_req,pru0 or pru1,PRU-ICSS0 Internal Interrupts
 18,pr1_pru_mst_intr[2]_intr_req,pru0 or pru1,PRU-ICSS0 Internal Interrupts
@@ -34,18 +34,18 @@ Event Number,Signal Name,Source,MII RT Signal Name
 32,nirq,UART1,PRU-ICSS0 PRU0_RX_ERR
 33,mcasp_x_intr[0]_pend,McASP1,Tx PRU-ICSS0 PRU0_RX_ERR32
 34,mcasp_r_intr[0]_pend,McASP1,Rx PRU-ICSS0 PRU0_RX_SFD
-35,ecap_intr[0]_intr_pend,eCAP1,PRU-ICSS0 PRU0_RX_SOF
-36,ecap_intr[1]_intr_pend,eCAP2,PRU-ICSS0 PRU0_RX_CRC
-37,epwm_intr[0]_intr_pend,eHRPWM2,PRU-ICSS0 PRU0_RX_NIBBLE_ODD
+35,ecap1_intr_pend,eCAP1,PRU-ICSS0 PRU0_RX_SOF
+36,ecap2_intr_pend,eCAP2,PRU-ICSS0 PRU0_RX_CRC
+37,epwm2_intr_pend,eHRPWM2,PRU-ICSS0 PRU0_RX_NIBBLE_ODD
 38,dcan_uerr,DCAN0,PRU-ICSS0 PRU0_RX_OVERFLOW
 39,dcan_int1,DCAN0,PRU-ICSS0 PORT0_TX_UNDERFLOW
 40,dcan_intr,DCAN0,PRU-ICSS0 PORT0_TX_OVERFLOW
 41,POINTRPEND,I2C0,PRU-ICSS0 MDIO_MII_LINK[0]
-42,ecap_intr[2]_intr_pend,eCAP0,PRU-ICSS0 PRU0_RX_EOF
-43,epwm_intr[1]_intr_pend,eHRPWM0,(pr1_mii0_col & pr1_mii0_txen) (external)
+42,ecap0_intr_pend,eCAP0,PRU-ICSS0 PRU0_RX_EOF
+43,epwm0_intr_pend,eHRPWM0,(pr1_mii0_col & pr1_mii0_txen) (external)
 44,SINTERRUPTN,McSPI0,PRU-ICSS0 PRU1_RX_ERR
 45,eqep_intr_intr_pend,eQEP0,PRU-ICSS0 PRU1_RX_ERR32
-46,epwm_intr[2]_intr_pend,eHRPWM1,PRU-ICSS0 PRU1_RX_SFD
+46,epwm1_intr_pend,eHRPWM1,PRU-ICSS0 PRU1_RX_SFD
 47,c0_misc_pend,3PGSW (GEMAC),PRU-ICSS0 PRU1_RX_SOF
 48,c0_tx_pend,3PGSW (GEMAC),PRU-ICSS0 PRU1_RX_CRC
 49,c0_rx_pend,3PGSW (GEMAC),PRU-ICSS0 PRU1_RX_NIBBLE_ODD

diff --git a/examples/BUILD b/examples/BUILD
diff --git a/examples/example.c b/examples/example.c
diff --git a/examples/led_outin/BUILD b/examples/led_outin/BUILD
@@ -0,0 +1,45 @@
+# -*- Mode: Python -*-
+cc_binary(
+    name = "led_outin",
+    srcs = [
+        "led_outin.c",
+        ":irqgen",
+    ],
+    additional_linker_inputs = [
+        "//tools/toolchain/am335x:linker_cmd",
+    ],
+    linkopts = [
+        "$(location //tools/toolchain/am335x:linker_cmd)",
+        "--stack_size=0x1000",
+    ],
+    deps = [
+        "//lib/coroutine",
+        "//lib/gpio",
+        "//lib/initproc",
+        "//lib/intc:service",
+        "//lib/log/daemon",
+        "//lib/rpmsg",
+        "//lib/time:process",
+        "//lib/resource",
+        "//tools/toolchain/am335x",
+    ],
+)
+
+genrule(
+    name = "irqgen",
+    srcs = [
+        # Order is important: args[0] is all events
+        # Remaining args define arriving system events.
+        # (Only) one should set the host.
+        "//arch:sysevts",
+        "//lib/rpmsg/am335x:irq",
+        "//lib/time/am335x:iep_tim_cap_cmp_pend",
+    ],
+    outs = [
+        "irq.c",
+    ],
+    cmd = "./$(location //tools/cmd/irqgen:irqgen) $(SRCS) > $@",
+    tools = [
+        "//tools/cmd/irqgen",
+    ],
+)
diff --git a/examples/led_outin/README.md b/examples/led_outin/README.md
@@ -0,0 +1 @@
+This example flashes a LED on pin P9_25 and reads the value on P9_23.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		This example flashes a LED on pin P9_25 and reads the value on P9_23.