Add BAM DMUX driver as network interface to the modem

arch/arm64/boot/dts/qcom/msm8916-modem.dtsi

@@ -7,6 +7,14 @@
 	status = "okay";
 };
 
+&bam_dmux {
+	status = "okay";
+};
+
+&bam_dmux_dma {
+	status = "okay";
+};
+
 &lpass {
 	status = "disabled";
 };

arch/arm64/boot/dts/qcom/msm8916.dtsi

@@ -225,6 +225,22 @@
 		};
 	};
 
+	bam_dmux: ethernet-bam-dmux {
+		compatible = "qcom,bam-dmux";
+
+		interrupt-parent = <&hexagon_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";
+
+		status = "disabled";
+	};
+
 	firmware {
 		scm: scm {
 			compatible = "qcom,scm-msm8916", "qcom,scm";
@@ -1281,6 +1297,20 @@
 			#interrupt-cells = <4>;
 		};
 
+		bam_dmux_dma: dma@4044000 {
+			compatible = "qcom,bam-v1.7.0";
+			reg = <0x04044000 0x19000>;
+			interrupts = <GIC_SPI 29 IRQ_TYPE_LEVEL_HIGH>;
+			#dma-cells = <1>;
+			qcom,ee = <0>;
+
+			num-channels = <6>;
+			qcom,num-ees = <1>;
+			qcom,remote-power-collapse;
+
+			status = "disabled";
+		};
+
 		mpss: remoteproc@4080000 {
 			compatible = "qcom,msm8916-mss-pil", "qcom,q6v5-pil";
 			reg = <0x04080000 0x100>,

arch/arm64/configs/msm8916_defconfig

@@ -141,6 +141,7 @@ CONFIG_MACVTAP=m
 CONFIG_VXLAN=m
 CONFIG_TUN=m
 CONFIG_VETH=m
+CONFIG_QCOM_BAM_DMUX=m
 CONFIG_RMNET=m
 CONFIG_WCN36XX=m
 CONFIG_INPUT_EVDEV=y

drivers/dma/qcom/bam_dma.c

@@ -389,6 +389,8 @@ struct bam_device {
 	/* execution environment ID, from DT */
 	u32 ee;
 	bool controlled_remotely;
+	bool remote_power_collapse;
+	u32 active_channels;
 
 	const struct reg_offset_data *layout;
 
@@ -490,6 +492,8 @@ static void bam_chan_init_hw(struct bam_chan *bchan,
 	bchan->tail = 0;
 }
 
+static void bam_reset(struct bam_device *bdev);
+
 /**
  * bam_alloc_chan - Allocate channel resources for DMA channel.
  * @chan: specified channel
@@ -513,6 +517,9 @@ static int bam_alloc_chan(struct dma_chan *chan)
 		return -ENOMEM;
 	}
 
+	if (bdev->active_channels++ == 0 && bdev->remote_power_collapse)
+		bam_reset(bdev);
+
 	return 0;
 }
 
@@ -566,6 +573,13 @@ static void bam_free_chan(struct dma_chan *chan)
 	/* disable irq */
 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
 
+	if (--bdev->active_channels == 0 && bdev->remote_power_collapse) {
+		/* s/w reset bam */
+		val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
+		val |= BAM_SW_RST;
+		writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
+	}
+
 err:
 	pm_runtime_mark_last_busy(bdev->dev);
 	pm_runtime_put_autosuspend(bdev->dev);
@@ -1144,34 +1158,10 @@ static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
 }
 
-/**
- * bam_init
- * @bdev: bam device
- *
- * Initialization helper for global bam registers
- */
-static int bam_init(struct bam_device *bdev)
+static void bam_reset(struct bam_device *bdev)
 {
 	u32 val;
 
-	/* read revision and configuration information */
-	if (!bdev->num_ees) {
-		val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
-		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
-	}
-
-	/* check that configured EE is within range */
-	if (bdev->ee >= bdev->num_ees)
-		return -EINVAL;
-
-	if (!bdev->num_channels) {
-		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
-		bdev->num_channels = val & BAM_NUM_PIPES_MASK;
-	}
-
-	if (bdev->controlled_remotely)
-		return 0;
-
 	/* s/w reset bam */
 	/* after reset all pipes are disabled and idle */
 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
@@ -1200,7 +1190,37 @@ static int bam_init(struct bam_device *bdev)
 
 	/* unmask global bam interrupt */
 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
+}
+
+/**
+ * bam_init
+ * @bdev: bam device
+ *
+ * Initialization helper for global bam registers
+ */
+static int bam_init(struct bam_device *bdev)
+{
+	u32 val;
+
+	/* read revision and configuration information */
+	if (!bdev->num_ees) {
+		val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
+		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
+	}
+
+	/* check that configured EE is within range */
+	if (bdev->ee >= bdev->num_ees)
+		return -EINVAL;
+
+	if (!bdev->num_channels) {
+		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
+		bdev->num_channels = val & BAM_NUM_PIPES_MASK;
+	}
+
+	if (bdev->controlled_remotely || bdev->remote_power_collapse)
+		return 0;
 
+	bam_reset(bdev);
 	return 0;
 }
 
@@ -1262,8 +1282,10 @@ static int bam_dma_probe(struct platform_device *pdev)
 
 	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
 						"qcom,controlled-remotely");
+	bdev->remote_power_collapse = of_property_read_bool(pdev->dev.of_node,
+						"qcom,remote-power-collapse");
 
-	if (bdev->controlled_remotely) {
+	if (bdev->controlled_remotely || bdev->remote_power_collapse) {
 		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
 					   &bdev->num_channels);
 		if (ret)
@@ -1277,7 +1299,7 @@ static int bam_dma_probe(struct platform_device *pdev)
 
 	bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
 	if (IS_ERR(bdev->bamclk)) {
-		if (!bdev->controlled_remotely)
+		if (!bdev->controlled_remotely && !bdev->remote_power_collapse)
 			return PTR_ERR(bdev->bamclk);
 
 		bdev->bamclk = NULL;
@@ -1356,7 +1378,7 @@ static int bam_dma_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_unregister_dma;
 
-	if (bdev->controlled_remotely) {
+	if (bdev->controlled_remotely || bdev->remote_power_collapse) {
 		pm_runtime_disable(&pdev->dev);
 		return 0;
 	}
@@ -1444,7 +1466,7 @@ static int __maybe_unused bam_dma_suspend(struct device *dev)
 {
 	struct bam_device *bdev = dev_get_drvdata(dev);
 
-	if (!bdev->controlled_remotely)
+	if (!bdev->controlled_remotely && !bdev->remote_power_collapse)
 		pm_runtime_force_suspend(dev);
 
 	clk_unprepare(bdev->bamclk);
@@ -1461,7 +1483,7 @@ static int __maybe_unused bam_dma_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	if (!bdev->controlled_remotely)
+	if (!bdev->controlled_remotely && !bdev->remote_power_collapse)
 		pm_runtime_force_resume(dev);
 
 	return 0;

drivers/net/ethernet/qualcomm/Kconfig

@@ -47,6 +47,10 @@ config QCA7000_UART
 	  To compile this driver as a module, choose M here. The module
 	  will be called qcauart.
 
+config QCOM_BAM_DMUX
+	tristate "Qualcomm BAM DMUX Ethernet/IP support"
+	select QCOM_SMEM_STATE
+
 config QCOM_EMAC
 	tristate "Qualcomm Technologies, Inc. EMAC Gigabit Ethernet support"
 	depends on HAS_DMA && HAS_IOMEM

drivers/net/ethernet/qualcomm/Makefile

@@ -8,6 +8,7 @@ obj-$(CONFIG_QCA7000_SPI) += qcaspi.o
 qcaspi-objs := qca_7k.o qca_debug.o qca_spi.o
 obj-$(CONFIG_QCA7000_UART) += qcauart.o
 qcauart-objs := qca_uart.o
+obj-$(CONFIG_QCOM_BAM_DMUX) += bam-dmux.o
 
 obj-y += emac/