Re: [PATCH] arm64: dts: qcom: shikra: Add BAM-DMUX support
From: Vishnu Santhosh
Date: Fri Jul 10 2026 - 23:54:37 EST
On 11-06-2026 02:25 pm, Stephan Gerhold wrote:
On Thu, Jun 11, 2026 at 02:11:59PM +0530, Vishnu Santhosh wrote:
Add required nodes to enable the upstream BAM-DMUX WWAN driver onI'm quite surprised to see this 15+ years(?) old hardware block being
Qualcomm Shikra SoC.
The SMSM (Shared Memory State Machine) node provides the power
control signaling between the AP and modem for BAM-DMUX. The
BAM DMA controller node describes the A2 modem BAM hardware as a
standard DMA controller. The BAM-DMUX node references the DMA
channels and the pc/pc-ack interrupt lines from the modem SMSM
entry for power control signaling.
Signed-off-by: Vishnu Santhosh <vishnu.santhosh@xxxxxxxxxxxxxxxx>
brought back to a new SoC. Is Shikra not using IPA?
---This should be a child node of the modem remoteproc. See msm8916.dtsi
arch/arm64/boot/dts/qcom/shikra.dtsi | 51 ++++++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
diff --git a/arch/arm64/boot/dts/qcom/shikra.dtsi b/arch/arm64/boot/dts/qcom/shikra.dtsi
index a4334d99c1f35ee851ca8266ec37d4a200a07ee5..3e59d5f6323c0d857f376316faa26c503e67f6bc 100644
--- a/arch/arm64/boot/dts/qcom/shikra.dtsi
+++ b/arch/arm64/boot/dts/qcom/shikra.dtsi
@@ -17,6 +17,23 @@ / {
#address-cells = <2>;
#size-cells = <2>;
+ bam_dmux: bam-dmux {
+ compatible = "qcom,bam-dmux";
+
+ interrupts-extended = <&modem_smsm 1 IRQ_TYPE_EDGE_BOTH>,
+ <&modem_smsm 11 IRQ_TYPE_EDGE_BOTH>;
+ interrupt-names = "pc",
+ "pc-ack";
+
+ qcom,smem-states = <&apps_smsm 1>,
+ <&apps_smsm 11>;
+ qcom,smem-state-names = "pc",
+ "pc-ack";
+
+ dmas = <&bam_dmux_dma 4>, <&bam_dmux_dma 5>;
+ dma-names = "tx", "rx";
+ };
for example.
+If the DT isn't merged yet, you can also just squash that into the
clocks {
xo_board: xo-board {
compatible = "fixed-clock";
@@ -314,6 +331,28 @@ lmcu_dtb_mem: lmcu-dtb@b4702000 {
};
};
+ smsm {
+ compatible = "qcom,smsm";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ mboxes = <0>, <&apcs_glb 13>;
+
+ apps_smsm: apps@0 {
+ reg = <0>;
+ #qcom,smem-state-cells = <1>;
+ };
+
+ modem_smsm: modem@1 {
+ reg = <1>;
+ interrupts = <GIC_SPI 69 IRQ_TYPE_EDGE_RISING 0>;
+
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ };
+ };
+
soc: soc@0 {
compatible = "simple-bus";
@@ -640,6 +679,18 @@ &clk_virt SLAVE_QUP_CORE_0 RPM_ALWAYS_TAG>,
};
};
+ bam_dmux_dma: dma-controller@6044000 {
+ compatible = "qcom,bam-v1.7.0";
+ reg = <0x0 0x06044000 0x0 0x19000>;
+ interrupts = <GIC_SPI 74 IRQ_TYPE_EDGE_RISING 0>;
+ #dma-cells = <1>;
+ qcom,ee = <0>;
+
+ num-channels = <6>;
+ qcom,num-ees = <1>;
+ qcom,powered-remotely;
+ };
+
sram@c11e000 {
compatible = "qcom,shikra-imem", "mmio-sram";
reg = <0x0 0x0c11e000 0x0 0x1000>;
---
base-commit: ba3e43a9e601636f5edb54e259a74f96ca3b8fd8
change-id: 20260603-qcom-shikra-dts-bam-dmux-7fdcbb6fb662
prerequisite-message-id: <20260527-shikra-dt-v4-0-b5ca1fa0b392@xxxxxxxxxxxxxxxx>
prerequisite-patch-id: 3a689e8dda5fd2755b689d94d095806b3f2e6eed
prerequisite-patch-id: 2acc300a68ed8c5364fb5f2f7d28fc0d56ab07bf
prerequisite-patch-id: 2357cac636e019eaf14d6a493a1c72bca56fe405
prerequisite-patch-id: 2885f299e711582da312ca9d13983d296a3dd5dc
prerequisite-patch-id: 91af5f3c01e766a53ce8de69aa21847a2d6bbbf8
existing series that adds the modem remoteproc.
Thanks,
Stephan
Since the existing series is already in a stable state, the author
does not want to add any more patches to it. Therefore, I will
update the current patch with the DT changes you suggested and
submit a separate patch to incorporate the corresponding driver
changes.
Thanks,
Vishnu