dmaengine: xilinx: xdma: Add user logic interrupt support

The Xilinx DMA/Bridge Subsystem for PCIe (XDMA) provides up to 16 user
interrupt wires to user logic that generate interrupts to the host.
This patch adds APIs to enable/disable user logic interrupt for a given
interrupt wire index.

Signed-off-by: Lizhi Hou <[e-mail]>
Signed-off-by: Sonal Santan <[e-mail]>
Signed-off-by: Max Zhen <[e-mail]>
Signed-off-by: Brian Xu <[e-mail]>
Tested-by: Martin Tuma <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

MAINTAINERS

···
 S:	Supported
 F:	drivers/dma/xilinx/xdma-regs.h
 F:	drivers/dma/xilinx/xdma.c
+F:	include/linux/dma/amd_xdma.h
 F:	include/linux/platform_data/amd_xdma.h
 
 XILINX ZYNQMP DPDMA DRIVER

drivers/dma/xilinx/xdma.c

···
 #include <linux/dmapool.h>
 #include <linux/regmap.h>
 #include <linux/dmaengine.h>
+#include <linux/dma/amd_xdma.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/amd_xdma.h>
 #include <linux/dma-mapping.h>
···
 static int xdma_irq_init(struct xdma_device *xdev)
 {
 	u32 irq = xdev->irq_start;
+	u32 user_irq_start;
 	int i, j, ret;
 
 	/* return failure if there are not enough IRQs */
···
 		goto failed_init_c2h;
 	}
 
+	/* config user IRQ registers if needed */
+	user_irq_start = XDMA_CHAN_NUM(xdev);
+	if (xdev->irq_num > user_irq_start) {
+		ret = xdma_set_vector_reg(xdev, XDMA_IRQ_USER_VEC_NUM,
+					  user_irq_start,
+					  xdev->irq_num - user_irq_start);
+		if (ret) {
+			xdma_err(xdev, "failed to set user vectors: %d", ret);
+			goto failed_init_c2h;
+		}
+	}
+
 	/* enable interrupt */
 	ret = regmap_write(xdev->rmap, XDMA_IRQ_CHAN_INT_EN_W1S, ~0);
 	if (ret)
···
 
 	return chan_info->dir == xdma_chan->dir;
 }
+
+/**
+ * xdma_disable_user_irq - Disable user interrupt
+ * @pdev: Pointer to the platform_device structure
+ * @irq_num: System IRQ number
+ */
+void xdma_disable_user_irq(struct platform_device *pdev, u32 irq_num)
+{
+	struct xdma_device *xdev = platform_get_drvdata(pdev);
+	u32 index;
+
+	index = irq_num - xdev->irq_start;
+	if (index < XDMA_CHAN_NUM(xdev) || index >= xdev->irq_num) {
+		xdma_err(xdev, "invalid user irq number");
+		return;
+	}
+	index -= XDMA_CHAN_NUM(xdev);
+
+	regmap_write(xdev->rmap, XDMA_IRQ_USER_INT_EN_W1C, 1 << index);
+}
+EXPORT_SYMBOL(xdma_disable_user_irq);
+
+/**
+ * xdma_enable_user_irq - Enable user logic interrupt
+ * @pdev: Pointer to the platform_device structure
+ * @irq_num: System IRQ number
+ */
+int xdma_enable_user_irq(struct platform_device *pdev, u32 irq_num)
+{
+	struct xdma_device *xdev = platform_get_drvdata(pdev);
+	u32 index;
+	int ret;
+
+	index = irq_num - xdev->irq_start;
+	if (index < XDMA_CHAN_NUM(xdev) || index >= xdev->irq_num) {
+		xdma_err(xdev, "invalid user irq number");
+		return -EINVAL;
+	}
+	index -= XDMA_CHAN_NUM(xdev);
+
+	ret = regmap_write(xdev->rmap, XDMA_IRQ_USER_INT_EN_W1S, 1 << index);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL(xdma_enable_user_irq);
+
+/**
+ * xdma_get_user_irq - Get system IRQ number
+ * @pdev: Pointer to the platform_device structure
+ * @user_irq_index: User logic IRQ wire index
+ *
+ * Return: The system IRQ number allocated for the given wire index.
+ */
+int xdma_get_user_irq(struct platform_device *pdev, u32 user_irq_index)
+{
+	struct xdma_device *xdev = platform_get_drvdata(pdev);
+
+	if (XDMA_CHAN_NUM(xdev) + user_irq_index >= xdev->irq_num) {
+		xdma_err(xdev, "invalid user irq index");
+		return -EINVAL;
+	}
+
+	return xdev->irq_start + XDMA_CHAN_NUM(xdev) + user_irq_index;
+}
+EXPORT_SYMBOL(xdma_get_user_irq);
 
 /**
  * xdma_remove - Driver remove function

include/linux/dma/amd_xdma.h

···
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2022, Advanced Micro Devices, Inc.
+ */
+
+#ifndef _DMAENGINE_AMD_XDMA_H
+#define _DMAENGINE_AMD_XDMA_H
+
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+int xdma_enable_user_irq(struct platform_device *pdev, u32 irq_num);
+void xdma_disable_user_irq(struct platform_device *pdev, u32 irq_num);
+int xdma_get_user_irq(struct platform_device *pdev, u32 user_irq_index);
+
+#endif /* _DMAENGINE_AMD_XDMA_H */