[参考译文] AM623：有关 AM6231 M 核程序和 DMA 冲突的问题

我尝试重新创建这一点,通过继续 main_spi0 将器件树中的相关更改关联到标准 SDK v8.6器件树中  k3-am625-sk.dts 并且未看到您报告的问题、则 M4仍可启动并运行。 但是、未在下找到 SPI 器件 /dev/spidev * ,甚至驱动程序在那里,我修复了几个问题与您的设备树。 我也尝试了非 RT 8.6版,但有同样的结果。 v8.6 SDK 和 spidev 似乎有一些一般问题。

但是、一旦我切换到 SDK v9.3、同样的器件树更改便顺利进行、也不会有任何问题。 以下是更新/修复的更改、供您查看：

$ git show
commit 6224a7f594d872adc7c3306f93027953d47910c1 (HEAD)
Author: Andreas Dannenberg <dannenberg@ti.com>
Date:   Sun Jan 5 23:09:44 2025 -0600

    dts: sk-am62: Enable dual spidev slaves

diff --git a/arch/arm64/boot/dts/ti/k3-am625-sk.dts b/arch/arm64/boot/dts/ti/k3-am625-sk.dts
index f9b7fa2e8156..c40d241da4c0 100644
--- a/arch/arm64/boot/dts/ti/k3-am625-sk.dts
+++ b/arch/arm64/boot/dts/ti/k3-am625-sk.dts
@@ -366,3 +366,45 @@ K3_TS_OFFSET(12, 17)
                        >;
        };
 };
+
+&main_pmx0 {
+        main_spi0_clk_data_pins_default: main-spi0-clk-data-pins-default {
+                pinctrl-single,pins = <
+                        AM62X_IOPAD(0x01bc, PIN_INPUT, 0) /* (A14) SPI0_CLK */
+                        AM62X_IOPAD(0x01c0, PIN_INPUT, 0) /* (B13) SPI0_D0 */
+                        AM62X_IOPAD(0x01c4, PIN_INPUT, 0) /* (B14) SPI0_D1 */
+                >;
+        };
+
+        main_spi0_cs0_pins_default: main-spi0-cs0-pins-default {
+                pinctrl-single,pins = <
+                        AM62X_IOPAD(0x01b4, PIN_INPUT, 0) /* (A13) SPI0_CS0 */
+                >;
+        };
+
+       main_spi0_cs1_pins_default: main-spi0-cs1-pins-default {
+                pinctrl-single,pins = <
+                        AM62X_IOPAD(0x01b8, PIN_INPUT, 0) /* (C13) SPI0_CS1 */
+                >;
+       };
+};
+
+&main_spi0 {
+       status = "okay";
+       pinctrl-names = "default";
+       pinctrl-0 = <&main_spi0_clk_data_pins_default &main_spi0_cs0_pins_default &main_spi0_cs1_pins_default>;
+       ti,spi-num-cs = <2>;
+       ti,pindir-d0-out-d1-in = <0>;
+
+       spidev@0 {
+               compatible = "rohm,dh2228fv";
+               spi-max-frequency = <500000000>;
+                reg = <0>;
+        };
+
+       spidev@1 {
+                compatible = "rohm,dh2228fv";
+                spi-max-frequency = <500000000>;
+                reg = <1>;
+        };
+};

由此、您可以看到一切都按预期运行：

root@am62xx-evm:~# uname -a
Linux am62xx-evm 6.1.83-rt28-ti-rt-g96b0ebd82722 #1 SMP PREEMPT_RT Mon May 13 23:06:24 UTC 2024 aarch64 aarch64 aarch64 GNU/Linux
root@am62xx-evm:~# dmesg | grep -i m4
[    0.000000] OF: reserved mem: initialized node m4f-dma-memory@9cb00000, compatible id shared-dma-pool
[    0.000000] OF: reserved mem: initialized node m4f-memory@9cc00000, compatible id shared-dma-pool
[    4.083703] k3-m4-rproc 5000000.m4fss: assigned reserved memory node m4f-dma-memory@9cb00000
[    4.090004] k3-m4-rproc 5000000.m4fss: configured M4 for remoteproc mode
[    4.090455] k3-m4-rproc 5000000.m4fss: local reset is deasserted for device
[    4.094554] remoteproc remoteproc0: 5000000.m4fss is available
[    4.099444] remoteproc remoteproc0: powering up 5000000.m4fss
[    4.099478] remoteproc remoteproc0: Booting fw image am62-mcu-m4f0_0-fw, size 55016
[    4.170538] rproc-virtio rproc-virtio.1.auto: assigned reserved memory node m4f-dma-memory@9cb00000
[    4.201675] remoteproc remoteproc0: remote processor 5000000.m4fss is now up
root@am62xx-evm:~# cat /sys/kernel/debug/remoteproc/remoteproc0/trace0
[m4f0-0]     0.000783s : [IPC RPMSG ECHO] Version: REL.MCUSDK.09.02.01.01+ (May 12 2024 22:05:58):
[m4f0-0]     0.052424s : [IPC RPMSG ECHO] Remote Core waiting for messages at end point 13 ... !!!
[m4f0-0]     0.056004s : [IPC RPMSG ECHO] Remote Core waiting for messages at end point 14 ... !!!
root@am62xx-evm:~# ls -al /dev/spi*
crw------- 1 root root 153, 0 Jan  1 00:00 /dev/spidev1.0
crw------- 1 root root 153, 1 Jan  1 00:00 /dev/spidev1.1
root@am62xx-evm:~#

您应该看到以下内容：

1. 迁移到当前的 SDK v10.1、然后重新实施所做的更改。 目前我们不能再支持 SDKv8.6。 我甚至不使用我使用的 v9.3了。 这些更改将以相同的方式与 SDK v10.1一起使用。
   
   
2. 如果要提高 SPI 性能、请考虑为两个 SPI 器件配置 DMA 的使用。 请参阅此处的 E2E 博文、它包含适用于2x SPI 从器件(具有 DMA 加速功能)的成熟解决方案：
   https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1425674/sk-am62-dma-transfer-is-not-working-with-spi0_cs1/5492317#5492317

此致、Andreas