Merge branch 'qualcomm-bam-dmux'

Stephan Gerhold says:

====================
net: wwan: Add Qualcomm BAM-DMUX WWAN network driver

The BAM Data Multiplexer provides access to the network data channels
of modems integrated into many older Qualcomm SoCs, e.g. Qualcomm MSM8916
or MSM8974. This series adds a driver that allows using it.

All the changes in this patch series are based on a quite complicated
driver from Qualcomm [1]. The driver has been used in postmarketOS [2]
on various smartphones/tablets based on Qualcomm MSM8916 and MSM8974
for more than a year now with no reported problems. It works out of
the box with open-source WWAN userspace such as ModemManager.

[1]: https://source.codeaurora.org/quic/la/kernel/msm-3.10/tree/drivers/soc/qcom/bam_dmux.c?h=LA.BR.1.2.9.1-02310-8x16.0
[2]: https://postmarketos.org/

Changes in v3:
  - Clarify DT schema based on discussion
  - Drop bam_dma/dmaengine patches since they already landed in 5.16
  - Rebase on net-next
  - Simplify cover letter and commit messages

Changes in v2:
  - Rename "qcom,remote-power-collapse" -> "qcom,powered-remotely"
  - Rebase on net-next and fix conflicts
  - Rename network interfaces from "rmnet%d" -> "wwan%d"
  - Fix wrong file name in MAINTAINERS entry
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/qcom,bam-dmux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm BAM Data Multiplexer
+
+maintainers:
+  - Stephan Gerhold <stephan@gerhold.net>
+
+description: |
+  The BAM Data Multiplexer provides access to the network data channels
+  of modems integrated into many older Qualcomm SoCs, e.g. Qualcomm MSM8916
+  or MSM8974. It is built using a simple protocol layer on top of a DMA engine
+  (Qualcomm BAM DMA) and bidirectional interrupts to coordinate power control.
+
+  Note that this schema does not directly describe a hardware block but rather
+  a firmware convention that combines several other hardware blocks (such as the
+  DMA engine). As such it is specific to a firmware version, not a particular
+  SoC or hardware version.
+
+properties:
+  compatible:
+    const: qcom,bam-dmux
+
+  interrupts:
+    description:
+      Interrupts used by the modem to signal the AP.
+      Both interrupts must be declared as IRQ_TYPE_EDGE_BOTH.
+    items:
+      - description: Power control
+      - description: Power control acknowledgment
+
+  interrupt-names:
+    items:
+      - const: pc
+      - const: pc-ack
+
+  qcom,smem-states:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description: State bits used by the AP to signal the modem.
+    items:
+      - description: Power control
+      - description: Power control acknowledgment
+
+  qcom,smem-state-names:
+    description: Names for the state bits used by the AP to signal the modem.
+    items:
+      - const: pc
+      - const: pc-ack
+
+  dmas:
+    items:
+      - description: TX DMA channel phandle
+      - description: RX DMA channel phandle
+
+  dma-names:
+    items:
+      - const: tx
+      - const: rx
+
+required:
+  - compatible
+  - interrupts
+  - interrupt-names
+  - qcom,smem-states
+  - qcom,smem-state-names
+  - dmas
+  - dma-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    mpss: remoteproc {
+        bam-dmux {
+            compatible = "qcom,bam-dmux";
+
+            interrupt-parent = <&modem_smsm>;
+            interrupts = <1 IRQ_TYPE_EDGE_BOTH>, <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";
+        };
+    };

MAINTAINERS

@@ -15727,6 +15727,14 @@ W:	https://wireless.wiki.kernel.org/en/users/Drivers/ath9k
 F:	Documentation/devicetree/bindings/net/wireless/qca,ath9k.yaml
 F:	drivers/net/wireless/ath/ath9k/
 
+QUALCOMM BAM-DMUX WWAN NETWORK DRIVER
+M:	Stephan Gerhold <stephan@gerhold.net>
+L:	netdev@vger.kernel.org
+L:	linux-arm-msm@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml
+F:	drivers/net/wwan/qcom_bam_dmux.c
+
 QUALCOMM CAMERA SUBSYSTEM DRIVER
 M:	Robert Foss <robert.foss@linaro.org>
 M:	Todor Tomov <todor.too@gmail.com>

drivers/net/wwan/Kconfig

@@ -50,6 +50,19 @@ config MHI_WWAN_MBIM
           To compile this driver as a module, choose M here: the module will be
           called mhi_wwan_mbim.
 
+config QCOM_BAM_DMUX
+	tristate "Qualcomm BAM-DMUX WWAN network driver"
+	depends on (DMA_ENGINE && PM && QCOM_SMEM_STATE) || COMPILE_TEST
+	help
+	  The BAM Data Multiplexer provides access to the network data channels
+	  of modems integrated into many older Qualcomm SoCs, e.g. Qualcomm
+	  MSM8916 or MSM8974. The connection can be established via QMI/AT from
+	  userspace with control ports available through the WWAN subsystem
+	  (CONFIG_RPMSG_WWAN_CTRL) or QRTR network sockets (CONFIG_QRTR).
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called qcom_bam_dmux.
+
 config RPMSG_WWAN_CTRL
 	tristate "RPMSG WWAN control driver"
 	depends on RPMSG

drivers/net/wwan/Makefile

@@ -10,5 +10,6 @@ obj-$(CONFIG_WWAN_HWSIM) += wwan_hwsim.o
 
 obj-$(CONFIG_MHI_WWAN_CTRL) += mhi_wwan_ctrl.o
 obj-$(CONFIG_MHI_WWAN_MBIM) += mhi_wwan_mbim.o
+obj-$(CONFIG_QCOM_BAM_DMUX) += qcom_bam_dmux.o
 obj-$(CONFIG_RPMSG_WWAN_CTRL) += rpmsg_wwan_ctrl.o
 obj-$(CONFIG_IOSM) += iosm/