drivers/fpga/zynq-fpga.c - kernel/bruno - Git at Google

 /*
  * Copyright (c) 2011-2015 Xilinx Inc.
  * Copyright (c) 2015, National Instruments Corp.
  *
  * FPGA Manager Driver for Xilinx Zynq, heavily based on xdevcfg driver
  * in their vendor tree.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; version 2 of the License.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  */

 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/fpga/fpga-mgr.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/mfd/syscon.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/pm.h>
 #include <linux/regmap.h>
 #include <linux/string.h>

 /* Offsets into SLCR regmap */

 /* FPGA Software Reset Control */
 #define SLCR_FPGA_RST_CTRL_OFFSET	0x240
 /* Level Shifters Enable */
 #define SLCR_LVL_SHFTR_EN_OFFSET	0x900

 /* Constant Definitions */

 /* Control Register */
 #define CTRL_OFFSET			0x00
 /* Lock Register */
 #define LOCK_OFFSET			0x04
 /* Interrupt Status Register */
 #define INT_STS_OFFSET			0x0c
 /* Interrupt Mask Register */
 #define INT_MASK_OFFSET			0x10
 /* Status Register */
 #define STATUS_OFFSET			0x14
 /* DMA Source Address Register */
 #define DMA_SRC_ADDR_OFFSET		0x18
 /* DMA Destination Address Reg */
 #define DMA_DST_ADDR_OFFSET		0x1c
 /* DMA Source Transfer Length */
 #define DMA_SRC_LEN_OFFSET		0x20
 /* DMA Destination Transfer */
 #define DMA_DEST_LEN_OFFSET		0x24
 /* Unlock Register */
 #define UNLOCK_OFFSET			0x34
 /* Misc. Control Register */
 #define MCTRL_OFFSET			0x80

 /* Control Register Bit definitions */

 /* Signal to reset FPGA */
 #define CTRL_PCFG_PROG_B_MASK		BIT(30)
 /* Enable PCAP for PR */
 #define CTRL_PCAP_PR_MASK		BIT(27)
 /* Enable PCAP */
 #define CTRL_PCAP_MODE_MASK		BIT(26)

 /* Miscellaneous Control Register bit definitions */
 /* Internal PCAP loopback */
 #define MCTRL_PCAP_LPBK_MASK		BIT(4)

 /* Status register bit definitions */

 /* FPGA init status */
 #define STATUS_DMA_Q_F			BIT(31)
 #define STATUS_PCFG_INIT_MASK		BIT(4)

 /* Interrupt Status/Mask Register Bit definitions */
 /* DMA command done */
 #define IXR_DMA_DONE_MASK		BIT(13)
 /* DMA and PCAP cmd done */
 #define IXR_D_P_DONE_MASK		BIT(12)
  /* FPGA programmed */
 #define IXR_PCFG_DONE_MASK		BIT(2)
 #define IXR_ERROR_FLAGS_MASK		0x00F0F860
 #define IXR_ALL_MASK			0xF8F7F87F

 /* Miscellaneous constant values */

 /* Invalid DMA addr */
 #define DMA_INVALID_ADDRESS		GENMASK(31, 0)
 /* Used to unlock the dev */
 #define UNLOCK_MASK			0x757bdf0d
 /* Timeout for DMA to complete */
 #define DMA_DONE_TIMEOUT		msecs_to_jiffies(1000)
 /* Timeout for polling reset bits */
 #define INIT_POLL_TIMEOUT		2500000
 /* Delay for polling reset bits */
 #define INIT_POLL_DELAY			20

 /* Masks for controlling stuff in SLCR */
 /* Disable all Level shifters */
 #define LVL_SHFTR_DISABLE_ALL_MASK	0x0
 /* Enable Level shifters from PS to PL */
 #define LVL_SHFTR_ENABLE_PS_TO_PL	0xa
 /* Enable Level shifters from PL to PS */
 #define LVL_SHFTR_ENABLE_PL_TO_PS	0xf
 /* Enable global resets */
 #define FPGA_RST_ALL_MASK		0xf
 /* Disable global resets */
 #define FPGA_RST_NONE_MASK		0x0

 struct zynq_fpga_priv {
 	struct device *dev;
 	int irq;
 	struct clk *clk;

 	void __iomem *io_base;
 	struct regmap *slcr;

 	struct completion dma_done;
 };

 static inline void zynq_fpga_write(struct zynq_fpga_priv *priv, u32 offset,
 				   u32 val)
 {
 	writel(val, priv->io_base + offset);
 }

 static inline u32 zynq_fpga_read(const struct zynq_fpga_priv *priv,
 				 u32 offset)
 {
 	return readl(priv->io_base + offset);
 }

 #define zynq_fpga_poll_timeout(priv, addr, val, cond, sleep_us, timeout_us) \
 	readl_poll_timeout(priv->io_base + addr, val, cond, sleep_us, \
 			   timeout_us)

 static void zynq_fpga_mask_irqs(struct zynq_fpga_priv *priv)
 {
 	u32 intr_mask;

 	intr_mask = zynq_fpga_read(priv, INT_MASK_OFFSET);
 	zynq_fpga_write(priv, INT_MASK_OFFSET,
 			intr_mask | IXR_DMA_DONE_MASK | IXR_ERROR_FLAGS_MASK);
 }

 static void zynq_fpga_unmask_irqs(struct zynq_fpga_priv *priv)
 {
 	u32 intr_mask;

 	intr_mask = zynq_fpga_read(priv, INT_MASK_OFFSET);
 	zynq_fpga_write(priv, INT_MASK_OFFSET,
 			intr_mask
 			& ~(IXR_D_P_DONE_MASK | IXR_ERROR_FLAGS_MASK));
 }

 static irqreturn_t zynq_fpga_isr(int irq, void *data)
 {
 	struct zynq_fpga_priv *priv = data;

 	/* disable DMA and error IRQs */
 	zynq_fpga_mask_irqs(priv);

 	complete(&priv->dma_done);

 	return IRQ_HANDLED;
 }

 static int zynq_fpga_ops_write_init(struct fpga_manager *mgr, u32 flags,
 				    const char *buf, size_t count)
 {
 	struct zynq_fpga_priv *priv;
 	u32 ctrl, status;
 	int err;

 	priv = mgr->priv;

 	err = clk_enable(priv->clk);
 	if (err)
 		return err;

 	/* don't globally reset PL if we're doing partial reconfig */
 	if (!(flags & FPGA_MGR_PARTIAL_RECONFIG)) {
 		/* assert AXI interface resets */
 		regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
 			     FPGA_RST_ALL_MASK);

 		/* disable all level shifters */
 		regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
 			     LVL_SHFTR_DISABLE_ALL_MASK);
 		/* enable level shifters from PS to PL */
 		regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
 			     LVL_SHFTR_ENABLE_PS_TO_PL);

 		/* create a rising edge on PCFG_INIT. PCFG_INIT follows
 		 * PCFG_PROG_B, so we need to poll it after setting PCFG_PROG_B
 		 * to make sure the rising edge actually happens.
 		 * Note: PCFG_PROG_B is low active, sequence as described in
 		 * UG585 v1.10 page 211
 		 */
 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
 		ctrl |= CTRL_PCFG_PROG_B_MASK;

 		zynq_fpga_write(priv, CTRL_OFFSET, ctrl);

 		err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
 					     status & STATUS_PCFG_INIT_MASK,
 					     INIT_POLL_DELAY,
 					     INIT_POLL_TIMEOUT);
 		if (err) {
 			dev_err(priv->dev, "Timeout waiting for PCFG_INIT");
 			goto out_err;
 		}

 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
 		ctrl &= ~CTRL_PCFG_PROG_B_MASK;

 		zynq_fpga_write(priv, CTRL_OFFSET, ctrl);

 		err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
 					     !(status & STATUS_PCFG_INIT_MASK),
 					     INIT_POLL_DELAY,
 					     INIT_POLL_TIMEOUT);
 		if (err) {
 			dev_err(priv->dev, "Timeout waiting for !PCFG_INIT");
 			goto out_err;
 		}

 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
 		ctrl |= CTRL_PCFG_PROG_B_MASK;

 		zynq_fpga_write(priv, CTRL_OFFSET, ctrl);

 		err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
 					     status & STATUS_PCFG_INIT_MASK,
 					     INIT_POLL_DELAY,
 					     INIT_POLL_TIMEOUT);
 		if (err) {
 			dev_err(priv->dev, "Timeout waiting for PCFG_INIT");
 			goto out_err;
 		}
 	}

 	/* set configuration register with following options:
 	 * - enable PCAP interface
 	 * - set throughput for maximum speed
 	 * - set CPU in user mode
 	 */
 	ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
 	zynq_fpga_write(priv, CTRL_OFFSET,
 			(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK | ctrl));

 	/* check that we have room in the command queue */
 	status = zynq_fpga_read(priv, STATUS_OFFSET);
 	if (status & STATUS_DMA_Q_F) {
 		dev_err(priv->dev, "DMA command queue full");
 		err = -EBUSY;
 		goto out_err;
 	}

 	/* ensure internal PCAP loopback is disabled */
 	ctrl = zynq_fpga_read(priv, MCTRL_OFFSET);
 	zynq_fpga_write(priv, MCTRL_OFFSET, (~MCTRL_PCAP_LPBK_MASK & ctrl));

 	clk_disable(priv->clk);

 	return 0;

 out_err:
 	clk_disable(priv->clk);

 	return err;
 }

 static int zynq_fpga_ops_write(struct fpga_manager *mgr,
 			       const char *buf, size_t count)
 {
 	struct zynq_fpga_priv *priv;
 	int err;
 	char *kbuf;
 	size_t in_count;
 	dma_addr_t dma_addr;
 	u32 transfer_length;
 	u32 intr_status;

 	in_count = count;
 	priv = mgr->priv;

 	kbuf = dma_alloc_coherent(priv->dev, count, &dma_addr, GFP_KERNEL);
 	if (!kbuf)
 		return -ENOMEM;

 	memcpy(kbuf, buf, count);

 	/* enable clock */
 	err = clk_enable(priv->clk);
 	if (err)
 		goto out_free;

 	zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);

 	reinit_completion(&priv->dma_done);

 	/* enable DMA and error IRQs */
 	zynq_fpga_unmask_irqs(priv);

 	/* the +1 in the src addr is used to hold off on DMA_DONE IRQ
 	 * until both AXI and PCAP are done ...
 	 */
 	zynq_fpga_write(priv, DMA_SRC_ADDR_OFFSET, (u32)(dma_addr) + 1);
 	zynq_fpga_write(priv, DMA_DST_ADDR_OFFSET, (u32)DMA_INVALID_ADDRESS);

 	/* convert #bytes to #words */
 	transfer_length = (count + 3) / 4;

 	zynq_fpga_write(priv, DMA_SRC_LEN_OFFSET, transfer_length);
 	zynq_fpga_write(priv, DMA_DEST_LEN_OFFSET, 0);

 	wait_for_completion(&priv->dma_done);

 	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
 	zynq_fpga_write(priv, INT_STS_OFFSET, intr_status);

 	if (!((intr_status & IXR_D_P_DONE_MASK) == IXR_D_P_DONE_MASK)) {
 		dev_err(priv->dev, "Error configuring FPGA");
 		err = -EFAULT;
 	}

 	clk_disable(priv->clk);

 out_free:
 	dma_free_coherent(priv->dev, in_count, kbuf, dma_addr);

 	return err;
 }

 static int zynq_fpga_ops_write_complete(struct fpga_manager *mgr, u32 flags)
 {
 	struct zynq_fpga_priv *priv = mgr->priv;
 	int err;
 	u32 intr_status;

 	err = clk_enable(priv->clk);
 	if (err)
 		return err;

 	err = zynq_fpga_poll_timeout(priv, INT_STS_OFFSET, intr_status,
 				     intr_status & IXR_PCFG_DONE_MASK,
 				     INIT_POLL_DELAY,
 				     INIT_POLL_TIMEOUT);

 	clk_disable(priv->clk);

 	if (err)
 		return err;

 	/* for the partial reconfig case we didn't touch the level shifters */
 	if (!(flags & FPGA_MGR_PARTIAL_RECONFIG)) {
 		/* enable level shifters from PL to PS */
 		regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
 			     LVL_SHFTR_ENABLE_PL_TO_PS);

 		/* deassert AXI interface resets */
 		regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
 			     FPGA_RST_NONE_MASK);
 	}

 	return 0;
 }

 static enum fpga_mgr_states zynq_fpga_ops_state(struct fpga_manager *mgr)
 {
 	int err;
 	u32 intr_status;
 	struct zynq_fpga_priv *priv;

 	priv = mgr->priv;

 	err = clk_enable(priv->clk);
 	if (err)
 		return FPGA_MGR_STATE_UNKNOWN;

 	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
 	clk_disable(priv->clk);

 	if (intr_status & IXR_PCFG_DONE_MASK)
 		return FPGA_MGR_STATE_OPERATING;

 	return FPGA_MGR_STATE_UNKNOWN;
 }

 static const struct fpga_manager_ops zynq_fpga_ops = {
 	.state = zynq_fpga_ops_state,
 	.write_init = zynq_fpga_ops_write_init,
 	.write = zynq_fpga_ops_write,
 	.write_complete = zynq_fpga_ops_write_complete,
 };

 static int zynq_fpga_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct zynq_fpga_priv *priv;
 	struct resource *res;
 	int err;

 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	priv->dev = dev;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	priv->io_base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(priv->io_base))
 		return PTR_ERR(priv->io_base);

 	priv->slcr = syscon_regmap_lookup_by_phandle(dev->of_node,
 		"syscon");
 	if (IS_ERR(priv->slcr)) {
 		dev_err(dev, "unable to get zynq-slcr regmap");
 		return PTR_ERR(priv->slcr);
 	}

 	init_completion(&priv->dma_done);

 	priv->irq = platform_get_irq(pdev, 0);
 	if (priv->irq < 0) {
 		dev_err(dev, "No IRQ available");
 		return priv->irq;
 	}

 	err = devm_request_irq(dev, priv->irq, zynq_fpga_isr, 0,
 			       dev_name(dev), priv);
 	if (err) {
 		dev_err(dev, "unable to request IRQ");
 		return err;
 	}

 	priv->clk = devm_clk_get(dev, "ref_clk");
 	if (IS_ERR(priv->clk)) {
 		dev_err(dev, "input clock not found");
 		return PTR_ERR(priv->clk);
 	}

 	err = clk_prepare_enable(priv->clk);
 	if (err) {
 		dev_err(dev, "unable to enable clock");
 		return err;
 	}

 	/* unlock the device */
 	zynq_fpga_write(priv, UNLOCK_OFFSET, UNLOCK_MASK);

 	clk_disable(priv->clk);

 	err = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
 				&zynq_fpga_ops, priv);
 	if (err) {
 		dev_err(dev, "unable to register FPGA manager");
 		clk_unprepare(priv->clk);
 		return err;
 	}

 	return 0;
 }

 static int zynq_fpga_remove(struct platform_device *pdev)
 {
 	struct zynq_fpga_priv *priv;
 	struct fpga_manager *mgr;

 	mgr = platform_get_drvdata(pdev);
 	priv = mgr->priv;

 	fpga_mgr_unregister(&pdev->dev);

 	clk_unprepare(priv->clk);

 	return 0;
 }

 #ifdef CONFIG_OF
 static const struct of_device_id zynq_fpga_of_match[] = {
 	{ .compatible = "xlnx,zynq-devcfg-1.0", },
 	{},
 };

 MODULE_DEVICE_TABLE(of, zynq_fpga_of_match);
 #endif

 static struct platform_driver zynq_fpga_driver = {
 	.probe = zynq_fpga_probe,
 	.remove = zynq_fpga_remove,
 	.driver = {
 		.name = "zynq_fpga_manager",
 		.of_match_table = of_match_ptr(zynq_fpga_of_match),
 	},
 };

 module_platform_driver(zynq_fpga_driver);

 MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
 MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
 MODULE_DESCRIPTION("Xilinx Zynq FPGA Manager");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright (c) 2011-2015 Xilinx Inc.
	* Copyright (c) 2015, National Instruments Corp.
	*
	* FPGA Manager Driver for Xilinx Zynq, heavily based on xdevcfg driver
	* in their vendor tree.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; version 2 of the License.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/clk.h>
	#include <linux/completion.h>
	#include <linux/delay.h>
	#include <linux/dma-mapping.h>
	#include <linux/fpga/fpga-mgr.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/iopoll.h>
	#include <linux/module.h>
	#include <linux/mfd/syscon.h>
	#include <linux/of_address.h>
	#include <linux/of_irq.h>
	#include <linux/pm.h>
	#include <linux/regmap.h>
	#include <linux/string.h>

	/* Offsets into SLCR regmap */

	/* FPGA Software Reset Control */
	#define SLCR_FPGA_RST_CTRL_OFFSET 0x240
	/* Level Shifters Enable */
	#define SLCR_LVL_SHFTR_EN_OFFSET 0x900

	/* Constant Definitions */

	/* Control Register */
	#define CTRL_OFFSET 0x00
	/* Lock Register */
	#define LOCK_OFFSET 0x04
	/* Interrupt Status Register */
	#define INT_STS_OFFSET 0x0c
	/* Interrupt Mask Register */
	#define INT_MASK_OFFSET 0x10
	/* Status Register */
	#define STATUS_OFFSET 0x14
	/* DMA Source Address Register */
	#define DMA_SRC_ADDR_OFFSET 0x18
	/* DMA Destination Address Reg */
	#define DMA_DST_ADDR_OFFSET 0x1c
	/* DMA Source Transfer Length */
	#define DMA_SRC_LEN_OFFSET 0x20
	/* DMA Destination Transfer */
	#define DMA_DEST_LEN_OFFSET 0x24
	/* Unlock Register */
	#define UNLOCK_OFFSET 0x34
	/* Misc. Control Register */
	#define MCTRL_OFFSET 0x80

	/* Control Register Bit definitions */

	/* Signal to reset FPGA */
	#define CTRL_PCFG_PROG_B_MASK BIT(30)
	/* Enable PCAP for PR */
	#define CTRL_PCAP_PR_MASK BIT(27)
	/* Enable PCAP */
	#define CTRL_PCAP_MODE_MASK BIT(26)

	/* Miscellaneous Control Register bit definitions */
	/* Internal PCAP loopback */
	#define MCTRL_PCAP_LPBK_MASK BIT(4)

	/* Status register bit definitions */

	/* FPGA init status */
	#define STATUS_DMA_Q_F BIT(31)
	#define STATUS_PCFG_INIT_MASK BIT(4)

	/* Interrupt Status/Mask Register Bit definitions */
	/* DMA command done */
	#define IXR_DMA_DONE_MASK BIT(13)
	/* DMA and PCAP cmd done */
	#define IXR_D_P_DONE_MASK BIT(12)
	/* FPGA programmed */
	#define IXR_PCFG_DONE_MASK BIT(2)
	#define IXR_ERROR_FLAGS_MASK 0x00F0F860
	#define IXR_ALL_MASK 0xF8F7F87F

	/* Miscellaneous constant values */

	/* Invalid DMA addr */
	#define DMA_INVALID_ADDRESS GENMASK(31, 0)
	/* Used to unlock the dev */
	#define UNLOCK_MASK 0x757bdf0d
	/* Timeout for DMA to complete */
	#define DMA_DONE_TIMEOUT msecs_to_jiffies(1000)
	/* Timeout for polling reset bits */
	#define INIT_POLL_TIMEOUT 2500000
	/* Delay for polling reset bits */
	#define INIT_POLL_DELAY 20

	/* Masks for controlling stuff in SLCR */
	/* Disable all Level shifters */
	#define LVL_SHFTR_DISABLE_ALL_MASK 0x0
	/* Enable Level shifters from PS to PL */
	#define LVL_SHFTR_ENABLE_PS_TO_PL 0xa
	/* Enable Level shifters from PL to PS */
	#define LVL_SHFTR_ENABLE_PL_TO_PS 0xf
	/* Enable global resets */
	#define FPGA_RST_ALL_MASK 0xf
	/* Disable global resets */
	#define FPGA_RST_NONE_MASK 0x0

	struct zynq_fpga_priv {
	struct device *dev;
	int irq;
	struct clk *clk;

	void __iomem *io_base;
	struct regmap *slcr;

	struct completion dma_done;
	};

	static inline void zynq_fpga_write(struct zynq_fpga_priv *priv, u32 offset,
	u32 val)
	{
	writel(val, priv->io_base + offset);
	}

	static inline u32 zynq_fpga_read(const struct zynq_fpga_priv *priv,
	u32 offset)
	{
	return readl(priv->io_base + offset);
	}

	#define zynq_fpga_poll_timeout(priv, addr, val, cond, sleep_us, timeout_us) \
	readl_poll_timeout(priv->io_base + addr, val, cond, sleep_us, \
	timeout_us)

	static void zynq_fpga_mask_irqs(struct zynq_fpga_priv *priv)
	{
	u32 intr_mask;

	intr_mask = zynq_fpga_read(priv, INT_MASK_OFFSET);
	zynq_fpga_write(priv, INT_MASK_OFFSET,
	intr_mask \| IXR_DMA_DONE_MASK \| IXR_ERROR_FLAGS_MASK);
	}

	static void zynq_fpga_unmask_irqs(struct zynq_fpga_priv *priv)
	{
	u32 intr_mask;

	intr_mask = zynq_fpga_read(priv, INT_MASK_OFFSET);
	zynq_fpga_write(priv, INT_MASK_OFFSET,
	intr_mask
	& ~(IXR_D_P_DONE_MASK \| IXR_ERROR_FLAGS_MASK));
	}

	static irqreturn_t zynq_fpga_isr(int irq, void *data)
	{
	struct zynq_fpga_priv *priv = data;

	/* disable DMA and error IRQs */
	zynq_fpga_mask_irqs(priv);

	complete(&priv->dma_done);

	return IRQ_HANDLED;
	}

	static int zynq_fpga_ops_write_init(struct fpga_manager *mgr, u32 flags,
	const char *buf, size_t count)
	{
	struct zynq_fpga_priv *priv;
	u32 ctrl, status;
	int err;

	priv = mgr->priv;

	err = clk_enable(priv->clk);
	if (err)
	return err;

	/* don't globally reset PL if we're doing partial reconfig */
	if (!(flags & FPGA_MGR_PARTIAL_RECONFIG)) {
	/* assert AXI interface resets */
	regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
	FPGA_RST_ALL_MASK);

	/* disable all level shifters */
	regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
	LVL_SHFTR_DISABLE_ALL_MASK);
	/* enable level shifters from PS to PL */
	regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
	LVL_SHFTR_ENABLE_PS_TO_PL);

	/* create a rising edge on PCFG_INIT. PCFG_INIT follows
	* PCFG_PROG_B, so we need to poll it after setting PCFG_PROG_B
	* to make sure the rising edge actually happens.
	* Note: PCFG_PROG_B is low active, sequence as described in
	* UG585 v1.10 page 211
	*/
	ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
	ctrl \|= CTRL_PCFG_PROG_B_MASK;

	zynq_fpga_write(priv, CTRL_OFFSET, ctrl);

	err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
	status & STATUS_PCFG_INIT_MASK,
	INIT_POLL_DELAY,
	INIT_POLL_TIMEOUT);
	if (err) {
	dev_err(priv->dev, "Timeout waiting for PCFG_INIT");
	goto out_err;
	}

	ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
	ctrl &= ~CTRL_PCFG_PROG_B_MASK;

	zynq_fpga_write(priv, CTRL_OFFSET, ctrl);

	err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
	!(status & STATUS_PCFG_INIT_MASK),
	INIT_POLL_DELAY,
	INIT_POLL_TIMEOUT);
	if (err) {
	dev_err(priv->dev, "Timeout waiting for !PCFG_INIT");
	goto out_err;
	}

	ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
	ctrl \|= CTRL_PCFG_PROG_B_MASK;

	zynq_fpga_write(priv, CTRL_OFFSET, ctrl);

	err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
	status & STATUS_PCFG_INIT_MASK,
	INIT_POLL_DELAY,
	INIT_POLL_TIMEOUT);
	if (err) {
	dev_err(priv->dev, "Timeout waiting for PCFG_INIT");
	goto out_err;
	}
	}

	/* set configuration register with following options:
	* - enable PCAP interface
	* - set throughput for maximum speed
	* - set CPU in user mode
	*/
	ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
	zynq_fpga_write(priv, CTRL_OFFSET,
	(CTRL_PCAP_PR_MASK \| CTRL_PCAP_MODE_MASK \| ctrl));

	/* check that we have room in the command queue */
	status = zynq_fpga_read(priv, STATUS_OFFSET);
	if (status & STATUS_DMA_Q_F) {
	dev_err(priv->dev, "DMA command queue full");
	err = -EBUSY;
	goto out_err;
	}

	/* ensure internal PCAP loopback is disabled */
	ctrl = zynq_fpga_read(priv, MCTRL_OFFSET);
	zynq_fpga_write(priv, MCTRL_OFFSET, (~MCTRL_PCAP_LPBK_MASK & ctrl));

	clk_disable(priv->clk);

	return 0;

	out_err:
	clk_disable(priv->clk);

	return err;
	}

	static int zynq_fpga_ops_write(struct fpga_manager *mgr,
	const char *buf, size_t count)
	{
	struct zynq_fpga_priv *priv;
	int err;
	char *kbuf;
	size_t in_count;
	dma_addr_t dma_addr;
	u32 transfer_length;
	u32 intr_status;

	in_count = count;
	priv = mgr->priv;

	kbuf = dma_alloc_coherent(priv->dev, count, &dma_addr, GFP_KERNEL);
	if (!kbuf)
	return -ENOMEM;

	memcpy(kbuf, buf, count);

	/* enable clock */
	err = clk_enable(priv->clk);
	if (err)
	goto out_free;

	zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);

	reinit_completion(&priv->dma_done);

	/* enable DMA and error IRQs */
	zynq_fpga_unmask_irqs(priv);

	/* the +1 in the src addr is used to hold off on DMA_DONE IRQ
	* until both AXI and PCAP are done ...
	*/
	zynq_fpga_write(priv, DMA_SRC_ADDR_OFFSET, (u32)(dma_addr) + 1);
	zynq_fpga_write(priv, DMA_DST_ADDR_OFFSET, (u32)DMA_INVALID_ADDRESS);

	/* convert #bytes to #words */
	transfer_length = (count + 3) / 4;

	zynq_fpga_write(priv, DMA_SRC_LEN_OFFSET, transfer_length);
	zynq_fpga_write(priv, DMA_DEST_LEN_OFFSET, 0);

	wait_for_completion(&priv->dma_done);

	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
	zynq_fpga_write(priv, INT_STS_OFFSET, intr_status);

	if (!((intr_status & IXR_D_P_DONE_MASK) == IXR_D_P_DONE_MASK)) {
	dev_err(priv->dev, "Error configuring FPGA");
	err = -EFAULT;
	}

	clk_disable(priv->clk);

	out_free:
	dma_free_coherent(priv->dev, in_count, kbuf, dma_addr);

	return err;
	}

	static int zynq_fpga_ops_write_complete(struct fpga_manager *mgr, u32 flags)
	{
	struct zynq_fpga_priv *priv = mgr->priv;
	int err;
	u32 intr_status;

	err = clk_enable(priv->clk);
	if (err)
	return err;

	err = zynq_fpga_poll_timeout(priv, INT_STS_OFFSET, intr_status,
	intr_status & IXR_PCFG_DONE_MASK,
	INIT_POLL_DELAY,
	INIT_POLL_TIMEOUT);

	clk_disable(priv->clk);

	if (err)
	return err;

	/* for the partial reconfig case we didn't touch the level shifters */
	if (!(flags & FPGA_MGR_PARTIAL_RECONFIG)) {
	/* enable level shifters from PL to PS */
	regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
	LVL_SHFTR_ENABLE_PL_TO_PS);

	/* deassert AXI interface resets */
	regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
	FPGA_RST_NONE_MASK);
	}

	return 0;
	}

	static enum fpga_mgr_states zynq_fpga_ops_state(struct fpga_manager *mgr)
	{
	int err;
	u32 intr_status;
	struct zynq_fpga_priv *priv;

	priv = mgr->priv;

	err = clk_enable(priv->clk);
	if (err)
	return FPGA_MGR_STATE_UNKNOWN;

	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
	clk_disable(priv->clk);

	if (intr_status & IXR_PCFG_DONE_MASK)
	return FPGA_MGR_STATE_OPERATING;

	return FPGA_MGR_STATE_UNKNOWN;
	}

	static const struct fpga_manager_ops zynq_fpga_ops = {
	.state = zynq_fpga_ops_state,
	.write_init = zynq_fpga_ops_write_init,
	.write = zynq_fpga_ops_write,
	.write_complete = zynq_fpga_ops_write_complete,
	};

	static int zynq_fpga_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct zynq_fpga_priv *priv;
	struct resource *res;
	int err;

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	priv->dev = dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->io_base = devm_ioremap_resource(dev, res);
	if (IS_ERR(priv->io_base))
	return PTR_ERR(priv->io_base);

	priv->slcr = syscon_regmap_lookup_by_phandle(dev->of_node,
	"syscon");
	if (IS_ERR(priv->slcr)) {
	dev_err(dev, "unable to get zynq-slcr regmap");
	return PTR_ERR(priv->slcr);
	}

	init_completion(&priv->dma_done);

	priv->irq = platform_get_irq(pdev, 0);
	if (priv->irq < 0) {
	dev_err(dev, "No IRQ available");
	return priv->irq;
	}

	err = devm_request_irq(dev, priv->irq, zynq_fpga_isr, 0,
	dev_name(dev), priv);
	if (err) {
	dev_err(dev, "unable to request IRQ");
	return err;
	}

	priv->clk = devm_clk_get(dev, "ref_clk");
	if (IS_ERR(priv->clk)) {
	dev_err(dev, "input clock not found");
	return PTR_ERR(priv->clk);
	}

	err = clk_prepare_enable(priv->clk);
	if (err) {
	dev_err(dev, "unable to enable clock");
	return err;
	}

	/* unlock the device */
	zynq_fpga_write(priv, UNLOCK_OFFSET, UNLOCK_MASK);

	clk_disable(priv->clk);

	err = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
	&zynq_fpga_ops, priv);
	if (err) {
	dev_err(dev, "unable to register FPGA manager");
	clk_unprepare(priv->clk);
	return err;
	}

	return 0;
	}

	static int zynq_fpga_remove(struct platform_device *pdev)
	{
	struct zynq_fpga_priv *priv;
	struct fpga_manager *mgr;

	mgr = platform_get_drvdata(pdev);
	priv = mgr->priv;

	fpga_mgr_unregister(&pdev->dev);

	clk_unprepare(priv->clk);

	return 0;
	}

	#ifdef CONFIG_OF
	static const struct of_device_id zynq_fpga_of_match[] = {
	{ .compatible = "xlnx,zynq-devcfg-1.0", },
	{},
	};

	MODULE_DEVICE_TABLE(of, zynq_fpga_of_match);
	#endif

	static struct platform_driver zynq_fpga_driver = {
	.probe = zynq_fpga_probe,
	.remove = zynq_fpga_remove,
	.driver = {
	.name = "zynq_fpga_manager",
	.of_match_table = of_match_ptr(zynq_fpga_of_match),
	},
	};

	module_platform_driver(zynq_fpga_driver);

	MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
	MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
	MODULE_DESCRIPTION("Xilinx Zynq FPGA Manager");
	MODULE_LICENSE("GPL v2");