drivers/fpga/altera-cvp.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * FPGA Manager Driver for Altera Arria/Cyclone/Stratix CvP
  *
  * Copyright (C) 2017 DENX Software Engineering
  *
  * Anatolij Gustschin <agust@denx.de>
  *
  * Manage Altera FPGA firmware using PCIe CvP.
  * Firmware must be in binary "rbf" format.
  */

 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/fpga/fpga-mgr.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/sizes.h>

 #define CVP_BAR		0	/* BAR used for data transfer in memory mode */
 #define CVP_DUMMY_WR	244	/* dummy writes to clear CvP state machine */
 #define TIMEOUT_US	2000	/* CVP STATUS timeout for USERMODE polling */

 /* Vendor Specific Extended Capability Registers */
 #define VSE_PCIE_EXT_CAP_ID		0x200
 #define VSE_PCIE_EXT_CAP_ID_VAL		0x000b	/* 16bit */

 #define VSE_CVP_STATUS			0x21c	/* 32bit */
 #define VSE_CVP_STATUS_CFG_RDY		BIT(18)	/* CVP_CONFIG_READY */
 #define VSE_CVP_STATUS_CFG_ERR		BIT(19)	/* CVP_CONFIG_ERROR */
 #define VSE_CVP_STATUS_CVP_EN		BIT(20)	/* ctrl block is enabling CVP */
 #define VSE_CVP_STATUS_USERMODE		BIT(21)	/* USERMODE */
 #define VSE_CVP_STATUS_CFG_DONE		BIT(23)	/* CVP_CONFIG_DONE */
 #define VSE_CVP_STATUS_PLD_CLK_IN_USE	BIT(24)	/* PLD_CLK_IN_USE */

 #define VSE_CVP_MODE_CTRL		0x220	/* 32bit */
 #define VSE_CVP_MODE_CTRL_CVP_MODE	BIT(0)	/* CVP (1) or normal mode (0) */
 #define VSE_CVP_MODE_CTRL_HIP_CLK_SEL	BIT(1) /* PMA (1) or fabric clock (0) */
 #define VSE_CVP_MODE_CTRL_NUMCLKS_OFF	8	/* NUMCLKS bits offset */
 #define VSE_CVP_MODE_CTRL_NUMCLKS_MASK	GENMASK(15, 8)

 #define VSE_CVP_DATA			0x228	/* 32bit */
 #define VSE_CVP_PROG_CTRL		0x22c	/* 32bit */
 #define VSE_CVP_PROG_CTRL_CONFIG	BIT(0)
 #define VSE_CVP_PROG_CTRL_START_XFER	BIT(1)

 #define VSE_UNCOR_ERR_STATUS		0x234	/* 32bit */
 #define VSE_UNCOR_ERR_CVP_CFG_ERR	BIT(5)	/* CVP_CONFIG_ERROR_LATCHED */

 #define DRV_NAME		"altera-cvp"
 #define ALTERA_CVP_MGR_NAME	"Altera CvP FPGA Manager"

 /* Optional CvP config error status check for debugging */
 static bool altera_cvp_chkcfg;

 struct altera_cvp_conf {
 	struct fpga_manager	*mgr;
 	struct pci_dev		*pci_dev;
 	void __iomem		*map;
 	void			(*write_data)(struct altera_cvp_conf *, u32);
 	char			mgr_name[64];
 	u8			numclks;
 };

 static enum fpga_mgr_states altera_cvp_state(struct fpga_manager *mgr)
 {
 	struct altera_cvp_conf *conf = mgr->priv;
 	u32 status;

 	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &status);

 	if (status & VSE_CVP_STATUS_CFG_DONE)
 		return FPGA_MGR_STATE_OPERATING;

 	if (status & VSE_CVP_STATUS_CVP_EN)
 		return FPGA_MGR_STATE_POWER_UP;

 	return FPGA_MGR_STATE_UNKNOWN;
 }

 static void altera_cvp_write_data_iomem(struct altera_cvp_conf *conf, u32 val)
 {
 	writel(val, conf->map);
 }

 static void altera_cvp_write_data_config(struct altera_cvp_conf *conf, u32 val)
 {
 	pci_write_config_dword(conf->pci_dev, VSE_CVP_DATA, val);
 }

 /* switches between CvP clock and internal clock */
 static void altera_cvp_dummy_write(struct altera_cvp_conf *conf)
 {
 	unsigned int i;
 	u32 val;

 	/* set 1 CVP clock cycle for every CVP Data Register Write */
 	pci_read_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, &val);
 	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
 	val |= 1 << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
 	pci_write_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, val);

 	for (i = 0; i < CVP_DUMMY_WR; i++)
 		conf->write_data(conf, 0); /* dummy data, could be any value */
 }

 static int altera_cvp_wait_status(struct altera_cvp_conf *conf, u32 status_mask,
 				  u32 status_val, int timeout_us)
 {
 	unsigned int retries;
 	u32 val;

 	retries = timeout_us / 10;
 	if (timeout_us % 10)
 		retries++;

 	do {
 		pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
 		if ((val & status_mask) == status_val)
 			return 0;

 		/* use small usleep value to re-check and break early */
 		usleep_range(10, 11);
 	} while (--retries);

 	return -ETIMEDOUT;
 }

 static int altera_cvp_teardown(struct fpga_manager *mgr,
 			       struct fpga_image_info *info)
 {
 	struct altera_cvp_conf *conf = mgr->priv;
 	struct pci_dev *pdev = conf->pci_dev;
 	int ret;
 	u32 val;

 	/* STEP 12 - reset START_XFER bit */
 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
 	val &= ~VSE_CVP_PROG_CTRL_START_XFER;
 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);

 	/* STEP 13 - reset CVP_CONFIG bit */
 	val &= ~VSE_CVP_PROG_CTRL_CONFIG;
 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);

 	/*
 	 * STEP 14
 	 * - set CVP_NUMCLKS to 1 and then issue CVP_DUMMY_WR dummy
 	 *   writes to the HIP
 	 */
 	altera_cvp_dummy_write(conf); /* from CVP clock to internal clock */

 	/* STEP 15 - poll CVP_CONFIG_READY bit for 0 with 10us timeout */
 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY, 0, 10);
 	if (ret)
 		dev_err(&mgr->dev, "CFG_RDY == 0 timeout\n");

 	return ret;
 }

 static int altera_cvp_write_init(struct fpga_manager *mgr,
 				 struct fpga_image_info *info,
 				 const char *buf, size_t count)
 {
 	struct altera_cvp_conf *conf = mgr->priv;
 	struct pci_dev *pdev = conf->pci_dev;
 	u32 iflags, val;
 	int ret;

 	iflags = info ? info->flags : 0;

 	if (iflags & FPGA_MGR_PARTIAL_RECONFIG) {
 		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
 		return -EINVAL;
 	}

 	/* Determine allowed clock to data ratio */
 	if (iflags & FPGA_MGR_COMPRESSED_BITSTREAM)
 		conf->numclks = 8; /* ratio for all compressed images */
 	else if (iflags & FPGA_MGR_ENCRYPTED_BITSTREAM)
 		conf->numclks = 4; /* for uncompressed and encrypted images */
 	else
 		conf->numclks = 1; /* for uncompressed and unencrypted images */

 	/* STEP 1 - read CVP status and check CVP_EN flag */
 	pci_read_config_dword(pdev, VSE_CVP_STATUS, &val);
 	if (!(val & VSE_CVP_STATUS_CVP_EN)) {
 		dev_err(&mgr->dev, "CVP mode off: 0x%04x\n", val);
 		return -ENODEV;
 	}

 	if (val & VSE_CVP_STATUS_CFG_RDY) {
 		dev_warn(&mgr->dev, "CvP already started, teardown first\n");
 		ret = altera_cvp_teardown(mgr, info);
 		if (ret)
 			return ret;
 	}

 	/*
 	 * STEP 2
 	 * - set HIP_CLK_SEL and CVP_MODE (must be set in the order mentioned)
 	 */
 	/* switch from fabric to PMA clock */
 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
 	val |= VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);

 	/* set CVP mode */
 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
 	val |= VSE_CVP_MODE_CTRL_CVP_MODE;
 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);

 	/*
 	 * STEP 3
 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
 	 */
 	altera_cvp_dummy_write(conf);

 	/* STEP 4 - set CVP_CONFIG bit */
 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
 	/* request control block to begin transfer using CVP */
 	val |= VSE_CVP_PROG_CTRL_CONFIG;
 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);

 	/* STEP 5 - poll CVP_CONFIG READY for 1 with 10us timeout */
 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY,
 				     VSE_CVP_STATUS_CFG_RDY, 10);
 	if (ret) {
 		dev_warn(&mgr->dev, "CFG_RDY == 1 timeout\n");
 		return ret;
 	}

 	/*
 	 * STEP 6
 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
 	 */
 	altera_cvp_dummy_write(conf);

 	/* STEP 7 - set START_XFER */
 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
 	val |= VSE_CVP_PROG_CTRL_START_XFER;
 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);

 	/* STEP 8 - start transfer (set CVP_NUMCLKS for bitstream) */
 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
 	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
 	val |= conf->numclks << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);

 	return 0;
 }

 static inline int altera_cvp_chk_error(struct fpga_manager *mgr, size_t bytes)
 {
 	struct altera_cvp_conf *conf = mgr->priv;
 	u32 val;

 	/* STEP 10 (optional) - check CVP_CONFIG_ERROR flag */
 	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
 	if (val & VSE_CVP_STATUS_CFG_ERR) {
 		dev_err(&mgr->dev, "CVP_CONFIG_ERROR after %zu bytes!\n",
 			bytes);
 		return -EPROTO;
 	}
 	return 0;
 }

 static int altera_cvp_write(struct fpga_manager *mgr, const char *buf,
 			    size_t count)
 {
 	struct altera_cvp_conf *conf = mgr->priv;
 	const u32 *data;
 	size_t done, remaining;
 	int status = 0;
 	u32 mask;

 	/* STEP 9 - write 32-bit data from RBF file to CVP data register */
 	data = (u32 *)buf;
 	remaining = count;
 	done = 0;

 	while (remaining >= 4) {
 		conf->write_data(conf, *data++);
 		done += 4;
 		remaining -= 4;

 		/*
 		 * STEP 10 (optional) and STEP 11
 		 * - check error flag
 		 * - loop until data transfer completed
 		 * Config images can be huge (more than 40 MiB), so
 		 * only check after a new 4k data block has been written.
 		 * This reduces the number of checks and speeds up the
 		 * configuration process.
 		 */
 		if (altera_cvp_chkcfg && !(done % SZ_4K)) {
 			status = altera_cvp_chk_error(mgr, done);
 			if (status < 0)
 				return status;
 		}
 	}

 	/* write up to 3 trailing bytes, if any */
 	mask = BIT(remaining * 8) - 1;
 	if (mask)
 		conf->write_data(conf, *data & mask);

 	if (altera_cvp_chkcfg)
 		status = altera_cvp_chk_error(mgr, count);

 	return status;
 }

 static int altera_cvp_write_complete(struct fpga_manager *mgr,
 				     struct fpga_image_info *info)
 {
 	struct altera_cvp_conf *conf = mgr->priv;
 	struct pci_dev *pdev = conf->pci_dev;
 	int ret;
 	u32 mask;
 	u32 val;

 	ret = altera_cvp_teardown(mgr, info);
 	if (ret)
 		return ret;

 	/* STEP 16 - check CVP_CONFIG_ERROR_LATCHED bit */
 	pci_read_config_dword(pdev, VSE_UNCOR_ERR_STATUS, &val);
 	if (val & VSE_UNCOR_ERR_CVP_CFG_ERR) {
 		dev_err(&mgr->dev, "detected CVP_CONFIG_ERROR_LATCHED!\n");
 		return -EPROTO;
 	}

 	/* STEP 17 - reset CVP_MODE and HIP_CLK_SEL bit */
 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
 	val &= ~VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
 	val &= ~VSE_CVP_MODE_CTRL_CVP_MODE;
 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);

 	/* STEP 18 - poll PLD_CLK_IN_USE and USER_MODE bits */
 	mask = VSE_CVP_STATUS_PLD_CLK_IN_USE | VSE_CVP_STATUS_USERMODE;
 	ret = altera_cvp_wait_status(conf, mask, mask, TIMEOUT_US);
 	if (ret)
 		dev_err(&mgr->dev, "PLD_CLK_IN_USE|USERMODE timeout\n");

 	return ret;
 }

 static const struct fpga_manager_ops altera_cvp_ops = {
 	.state		= altera_cvp_state,
 	.write_init	= altera_cvp_write_init,
 	.write		= altera_cvp_write,
 	.write_complete	= altera_cvp_write_complete,
 };

 static ssize_t chkcfg_show(struct device_driver *dev, char *buf)
 {
 	return snprintf(buf, 3, "%d\n", altera_cvp_chkcfg);
 }

 static ssize_t chkcfg_store(struct device_driver *drv, const char *buf,
 			    size_t count)
 {
 	int ret;

 	ret = kstrtobool(buf, &altera_cvp_chkcfg);
 	if (ret)
 		return ret;

 	return count;
 }

 static DRIVER_ATTR_RW(chkcfg);

 static int altera_cvp_probe(struct pci_dev *pdev,
 			    const struct pci_device_id *dev_id);
 static void altera_cvp_remove(struct pci_dev *pdev);

 static struct pci_device_id altera_cvp_id_tbl[] = {
 	{ PCI_VDEVICE(ALTERA, PCI_ANY_ID) },
 	{ }
 };
 MODULE_DEVICE_TABLE(pci, altera_cvp_id_tbl);

 static struct pci_driver altera_cvp_driver = {
 	.name   = DRV_NAME,
 	.id_table = altera_cvp_id_tbl,
 	.probe  = altera_cvp_probe,
 	.remove = altera_cvp_remove,
 };

 static int altera_cvp_probe(struct pci_dev *pdev,
 			    const struct pci_device_id *dev_id)
 {
 	struct altera_cvp_conf *conf;
 	struct fpga_manager *mgr;
 	u16 cmd, val;
 	u32 regval;
 	int ret;

 	/*
 	 * First check if this is the expected FPGA device. PCI config
 	 * space access works without enabling the PCI device, memory
 	 * space access is enabled further down.
 	 */
 	pci_read_config_word(pdev, VSE_PCIE_EXT_CAP_ID, &val);
 	if (val != VSE_PCIE_EXT_CAP_ID_VAL) {
 		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value 0x%x\n", val);
 		return -ENODEV;
 	}

 	pci_read_config_dword(pdev, VSE_CVP_STATUS, &regval);
 	if (!(regval & VSE_CVP_STATUS_CVP_EN)) {
 		dev_err(&pdev->dev,
 			"CVP is disabled for this device: CVP_STATUS Reg 0x%x\n",
 			regval);
 		return -ENODEV;
 	}

 	conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
 	if (!conf)
 		return -ENOMEM;

 	/*
 	 * Enable memory BAR access. We cannot use pci_enable_device() here
 	 * because it will make the driver unusable with FPGA devices that
 	 * have additional big IOMEM resources (e.g. 4GiB BARs) on 32-bit
 	 * platform. Such BARs will not have an assigned address range and
 	 * pci_enable_device() will fail, complaining about not claimed BAR,
 	 * even if the concerned BAR is not needed for FPGA configuration
 	 * at all. Thus, enable the device via PCI config space command.
 	 */
 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
 	if (!(cmd & PCI_COMMAND_MEMORY)) {
 		cmd |= PCI_COMMAND_MEMORY;
 		pci_write_config_word(pdev, PCI_COMMAND, cmd);
 	}

 	ret = pci_request_region(pdev, CVP_BAR, "CVP");
 	if (ret) {
 		dev_err(&pdev->dev, "Requesting CVP BAR region failed\n");
 		goto err_disable;
 	}

 	conf->pci_dev = pdev;
 	conf->write_data = altera_cvp_write_data_iomem;

 	conf->map = pci_iomap(pdev, CVP_BAR, 0);
 	if (!conf->map) {
 		dev_warn(&pdev->dev, "Mapping CVP BAR failed\n");
 		conf->write_data = altera_cvp_write_data_config;
 	}

 	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
 		 ALTERA_CVP_MGR_NAME, pci_name(pdev));

 	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
 				   &altera_cvp_ops, conf);
 	if (!mgr) {
 		ret = -ENOMEM;
 		goto err_unmap;
 	}

 	pci_set_drvdata(pdev, mgr);

 	ret = fpga_mgr_register(mgr);
 	if (ret)
 		goto err_unmap;

 	return 0;

 err_unmap:
 	if (conf->map)
 		pci_iounmap(pdev, conf->map);
 	pci_release_region(pdev, CVP_BAR);
 err_disable:
 	cmd &= ~PCI_COMMAND_MEMORY;
 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
 	return ret;
 }

 static void altera_cvp_remove(struct pci_dev *pdev)
 {
 	struct fpga_manager *mgr = pci_get_drvdata(pdev);
 	struct altera_cvp_conf *conf = mgr->priv;
 	u16 cmd;

 	fpga_mgr_unregister(mgr);
 	if (conf->map)
 		pci_iounmap(pdev, conf->map);
 	pci_release_region(pdev, CVP_BAR);
 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
 	cmd &= ~PCI_COMMAND_MEMORY;
 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
 }

 static int __init altera_cvp_init(void)
 {
 	int ret;

 	ret = pci_register_driver(&altera_cvp_driver);
 	if (ret)
 		return ret;

 	ret = driver_create_file(&altera_cvp_driver.driver,
 				 &driver_attr_chkcfg);
 	if (ret)
 		pr_warn("Can't create sysfs chkcfg file\n");

 	return 0;
 }

 static void __exit altera_cvp_exit(void)
 {
 	driver_remove_file(&altera_cvp_driver.driver, &driver_attr_chkcfg);
 	pci_unregister_driver(&altera_cvp_driver);
 }

 module_init(altera_cvp_init);
 module_exit(altera_cvp_exit);

 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
 MODULE_DESCRIPTION("Module to load Altera FPGA over CvP");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* FPGA Manager Driver for Altera Arria/Cyclone/Stratix CvP
	*
	* Copyright (C) 2017 DENX Software Engineering
	*
	* Anatolij Gustschin <agust@denx.de>
	*
	* Manage Altera FPGA firmware using PCIe CvP.
	* Firmware must be in binary "rbf" format.
	*/

	#include <linux/delay.h>
	#include <linux/device.h>
	#include <linux/fpga/fpga-mgr.h>
	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/sizes.h>

	#define CVP_BAR 0 /* BAR used for data transfer in memory mode */
	#define CVP_DUMMY_WR 244 /* dummy writes to clear CvP state machine */
	#define TIMEOUT_US 2000 /* CVP STATUS timeout for USERMODE polling */

	/* Vendor Specific Extended Capability Registers */
	#define VSE_PCIE_EXT_CAP_ID 0x200
	#define VSE_PCIE_EXT_CAP_ID_VAL 0x000b /* 16bit */

	#define VSE_CVP_STATUS 0x21c /* 32bit */
	#define VSE_CVP_STATUS_CFG_RDY BIT(18) /* CVP_CONFIG_READY */
	#define VSE_CVP_STATUS_CFG_ERR BIT(19) /* CVP_CONFIG_ERROR */
	#define VSE_CVP_STATUS_CVP_EN BIT(20) /* ctrl block is enabling CVP */
	#define VSE_CVP_STATUS_USERMODE BIT(21) /* USERMODE */
	#define VSE_CVP_STATUS_CFG_DONE BIT(23) /* CVP_CONFIG_DONE */
	#define VSE_CVP_STATUS_PLD_CLK_IN_USE BIT(24) /* PLD_CLK_IN_USE */

	#define VSE_CVP_MODE_CTRL 0x220 /* 32bit */
	#define VSE_CVP_MODE_CTRL_CVP_MODE BIT(0) /* CVP (1) or normal mode (0) */
	#define VSE_CVP_MODE_CTRL_HIP_CLK_SEL BIT(1) /* PMA (1) or fabric clock (0) */
	#define VSE_CVP_MODE_CTRL_NUMCLKS_OFF 8 /* NUMCLKS bits offset */
	#define VSE_CVP_MODE_CTRL_NUMCLKS_MASK GENMASK(15, 8)

	#define VSE_CVP_DATA 0x228 /* 32bit */
	#define VSE_CVP_PROG_CTRL 0x22c /* 32bit */
	#define VSE_CVP_PROG_CTRL_CONFIG BIT(0)
	#define VSE_CVP_PROG_CTRL_START_XFER BIT(1)

	#define VSE_UNCOR_ERR_STATUS 0x234 /* 32bit */
	#define VSE_UNCOR_ERR_CVP_CFG_ERR BIT(5) /* CVP_CONFIG_ERROR_LATCHED */

	#define DRV_NAME "altera-cvp"
	#define ALTERA_CVP_MGR_NAME "Altera CvP FPGA Manager"

	/* Optional CvP config error status check for debugging */
	static bool altera_cvp_chkcfg;

	struct altera_cvp_conf {
	struct fpga_manager *mgr;
	struct pci_dev *pci_dev;
	void __iomem *map;
	void (write_data)(struct altera_cvp_conf , u32);
	char mgr_name[64];
	u8 numclks;
	};

	static enum fpga_mgr_states altera_cvp_state(struct fpga_manager *mgr)
	{
	struct altera_cvp_conf *conf = mgr->priv;
	u32 status;

	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &status);

	if (status & VSE_CVP_STATUS_CFG_DONE)
	return FPGA_MGR_STATE_OPERATING;

	if (status & VSE_CVP_STATUS_CVP_EN)
	return FPGA_MGR_STATE_POWER_UP;

	return FPGA_MGR_STATE_UNKNOWN;
	}

	static void altera_cvp_write_data_iomem(struct altera_cvp_conf *conf, u32 val)
	{
	writel(val, conf->map);
	}

	static void altera_cvp_write_data_config(struct altera_cvp_conf *conf, u32 val)
	{
	pci_write_config_dword(conf->pci_dev, VSE_CVP_DATA, val);
	}

	/* switches between CvP clock and internal clock */
	static void altera_cvp_dummy_write(struct altera_cvp_conf *conf)
	{
	unsigned int i;
	u32 val;

	/* set 1 CVP clock cycle for every CVP Data Register Write */
	pci_read_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, &val);
	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
	val \|= 1 << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
	pci_write_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, val);

	for (i = 0; i < CVP_DUMMY_WR; i++)
	conf->write_data(conf, 0); /* dummy data, could be any value */
	}

	static int altera_cvp_wait_status(struct altera_cvp_conf *conf, u32 status_mask,
	u32 status_val, int timeout_us)
	{
	unsigned int retries;
	u32 val;

	retries = timeout_us / 10;
	if (timeout_us % 10)
	retries++;

	do {
	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
	if ((val & status_mask) == status_val)
	return 0;

	/* use small usleep value to re-check and break early */
	usleep_range(10, 11);
	} while (--retries);

	return -ETIMEDOUT;
	}

	static int altera_cvp_teardown(struct fpga_manager *mgr,
	struct fpga_image_info *info)
	{
	struct altera_cvp_conf *conf = mgr->priv;
	struct pci_dev *pdev = conf->pci_dev;
	int ret;
	u32 val;

	/* STEP 12 - reset START_XFER bit */
	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
	val &= ~VSE_CVP_PROG_CTRL_START_XFER;
	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);

	/* STEP 13 - reset CVP_CONFIG bit */
	val &= ~VSE_CVP_PROG_CTRL_CONFIG;
	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);

	/*
	* STEP 14
	* - set CVP_NUMCLKS to 1 and then issue CVP_DUMMY_WR dummy
	* writes to the HIP
	*/
	altera_cvp_dummy_write(conf); /* from CVP clock to internal clock */

	/* STEP 15 - poll CVP_CONFIG_READY bit for 0 with 10us timeout */
	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY, 0, 10);
	if (ret)
	dev_err(&mgr->dev, "CFG_RDY == 0 timeout\n");

	return ret;
	}

	static int altera_cvp_write_init(struct fpga_manager *mgr,
	struct fpga_image_info *info,
	const char *buf, size_t count)
	{
	struct altera_cvp_conf *conf = mgr->priv;
	struct pci_dev *pdev = conf->pci_dev;
	u32 iflags, val;
	int ret;

	iflags = info ? info->flags : 0;

	if (iflags & FPGA_MGR_PARTIAL_RECONFIG) {
	dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
	return -EINVAL;
	}

	/* Determine allowed clock to data ratio */
	if (iflags & FPGA_MGR_COMPRESSED_BITSTREAM)
	conf->numclks = 8; /* ratio for all compressed images */
	else if (iflags & FPGA_MGR_ENCRYPTED_BITSTREAM)
	conf->numclks = 4; /* for uncompressed and encrypted images */
	else
	conf->numclks = 1; /* for uncompressed and unencrypted images */

	/* STEP 1 - read CVP status and check CVP_EN flag */
	pci_read_config_dword(pdev, VSE_CVP_STATUS, &val);
	if (!(val & VSE_CVP_STATUS_CVP_EN)) {
	dev_err(&mgr->dev, "CVP mode off: 0x%04x\n", val);
	return -ENODEV;
	}

	if (val & VSE_CVP_STATUS_CFG_RDY) {
	dev_warn(&mgr->dev, "CvP already started, teardown first\n");
	ret = altera_cvp_teardown(mgr, info);
	if (ret)
	return ret;
	}

	/*
	* STEP 2
	* - set HIP_CLK_SEL and CVP_MODE (must be set in the order mentioned)
	*/
	/* switch from fabric to PMA clock */
	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
	val \|= VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);

	/* set CVP mode */
	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
	val \|= VSE_CVP_MODE_CTRL_CVP_MODE;
	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);

	/*
	* STEP 3
	* - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
	*/
	altera_cvp_dummy_write(conf);

	/* STEP 4 - set CVP_CONFIG bit */
	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
	/* request control block to begin transfer using CVP */
	val \|= VSE_CVP_PROG_CTRL_CONFIG;
	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);

	/* STEP 5 - poll CVP_CONFIG READY for 1 with 10us timeout */
	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY,
	VSE_CVP_STATUS_CFG_RDY, 10);
	if (ret) {
	dev_warn(&mgr->dev, "CFG_RDY == 1 timeout\n");
	return ret;
	}

	/*
	* STEP 6
	* - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
	*/
	altera_cvp_dummy_write(conf);

	/* STEP 7 - set START_XFER */
	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
	val \|= VSE_CVP_PROG_CTRL_START_XFER;
	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);

	/* STEP 8 - start transfer (set CVP_NUMCLKS for bitstream) */
	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
	val \|= conf->numclks << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);

	return 0;
	}

	static inline int altera_cvp_chk_error(struct fpga_manager *mgr, size_t bytes)
	{
	struct altera_cvp_conf *conf = mgr->priv;
	u32 val;

	/* STEP 10 (optional) - check CVP_CONFIG_ERROR flag */
	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
	if (val & VSE_CVP_STATUS_CFG_ERR) {
	dev_err(&mgr->dev, "CVP_CONFIG_ERROR after %zu bytes!\n",
	bytes);
	return -EPROTO;
	}
	return 0;
	}

	static int altera_cvp_write(struct fpga_manager mgr, const char buf,
	size_t count)
	{
	struct altera_cvp_conf *conf = mgr->priv;
	const u32 *data;
	size_t done, remaining;
	int status = 0;
	u32 mask;

	/* STEP 9 - write 32-bit data from RBF file to CVP data register */
	data = (u32 *)buf;
	remaining = count;
	done = 0;

	while (remaining >= 4) {
	conf->write_data(conf, *data++);
	done += 4;
	remaining -= 4;

	/*
	* STEP 10 (optional) and STEP 11
	* - check error flag
	* - loop until data transfer completed
	* Config images can be huge (more than 40 MiB), so
	* only check after a new 4k data block has been written.
	* This reduces the number of checks and speeds up the
	* configuration process.
	*/
	if (altera_cvp_chkcfg && !(done % SZ_4K)) {
	status = altera_cvp_chk_error(mgr, done);
	if (status < 0)
	return status;
	}
	}

	/* write up to 3 trailing bytes, if any */
	mask = BIT(remaining * 8) - 1;
	if (mask)
	conf->write_data(conf, *data & mask);

	if (altera_cvp_chkcfg)
	status = altera_cvp_chk_error(mgr, count);

	return status;
	}

	static int altera_cvp_write_complete(struct fpga_manager *mgr,
	struct fpga_image_info *info)
	{
	struct altera_cvp_conf *conf = mgr->priv;
	struct pci_dev *pdev = conf->pci_dev;
	int ret;
	u32 mask;
	u32 val;

	ret = altera_cvp_teardown(mgr, info);
	if (ret)
	return ret;

	/* STEP 16 - check CVP_CONFIG_ERROR_LATCHED bit */
	pci_read_config_dword(pdev, VSE_UNCOR_ERR_STATUS, &val);
	if (val & VSE_UNCOR_ERR_CVP_CFG_ERR) {
	dev_err(&mgr->dev, "detected CVP_CONFIG_ERROR_LATCHED!\n");
	return -EPROTO;
	}

	/* STEP 17 - reset CVP_MODE and HIP_CLK_SEL bit */
	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
	val &= ~VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
	val &= ~VSE_CVP_MODE_CTRL_CVP_MODE;
	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);

	/* STEP 18 - poll PLD_CLK_IN_USE and USER_MODE bits */
	mask = VSE_CVP_STATUS_PLD_CLK_IN_USE \| VSE_CVP_STATUS_USERMODE;
	ret = altera_cvp_wait_status(conf, mask, mask, TIMEOUT_US);
	if (ret)
	dev_err(&mgr->dev, "PLD_CLK_IN_USE\|USERMODE timeout\n");

	return ret;
	}

	static const struct fpga_manager_ops altera_cvp_ops = {
	.state = altera_cvp_state,
	.write_init = altera_cvp_write_init,
	.write = altera_cvp_write,
	.write_complete = altera_cvp_write_complete,
	};

	static ssize_t chkcfg_show(struct device_driver dev, char buf)
	{
	return snprintf(buf, 3, "%d\n", altera_cvp_chkcfg);
	}

	static ssize_t chkcfg_store(struct device_driver drv, const char buf,
	size_t count)
	{
	int ret;

	ret = kstrtobool(buf, &altera_cvp_chkcfg);
	if (ret)
	return ret;

	return count;
	}

	static DRIVER_ATTR_RW(chkcfg);

	static int altera_cvp_probe(struct pci_dev *pdev,
	const struct pci_device_id *dev_id);
	static void altera_cvp_remove(struct pci_dev *pdev);

	static struct pci_device_id altera_cvp_id_tbl[] = {
	{ PCI_VDEVICE(ALTERA, PCI_ANY_ID) },
	{ }
	};
	MODULE_DEVICE_TABLE(pci, altera_cvp_id_tbl);

	static struct pci_driver altera_cvp_driver = {
	.name = DRV_NAME,
	.id_table = altera_cvp_id_tbl,
	.probe = altera_cvp_probe,
	.remove = altera_cvp_remove,
	};

	static int altera_cvp_probe(struct pci_dev *pdev,
	const struct pci_device_id *dev_id)
	{
	struct altera_cvp_conf *conf;
	struct fpga_manager *mgr;
	u16 cmd, val;
	u32 regval;
	int ret;

	/*
	* First check if this is the expected FPGA device. PCI config
	* space access works without enabling the PCI device, memory
	* space access is enabled further down.
	*/
	pci_read_config_word(pdev, VSE_PCIE_EXT_CAP_ID, &val);
	if (val != VSE_PCIE_EXT_CAP_ID_VAL) {
	dev_err(&pdev->dev, "Wrong EXT_CAP_ID value 0x%x\n", val);
	return -ENODEV;
	}

	pci_read_config_dword(pdev, VSE_CVP_STATUS, &regval);
	if (!(regval & VSE_CVP_STATUS_CVP_EN)) {
	dev_err(&pdev->dev,
	"CVP is disabled for this device: CVP_STATUS Reg 0x%x\n",
	regval);
	return -ENODEV;
	}

	conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
	if (!conf)
	return -ENOMEM;

	/*
	* Enable memory BAR access. We cannot use pci_enable_device() here
	* because it will make the driver unusable with FPGA devices that
	* have additional big IOMEM resources (e.g. 4GiB BARs) on 32-bit
	* platform. Such BARs will not have an assigned address range and
	* pci_enable_device() will fail, complaining about not claimed BAR,
	* even if the concerned BAR is not needed for FPGA configuration
	* at all. Thus, enable the device via PCI config space command.
	*/
	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
	if (!(cmd & PCI_COMMAND_MEMORY)) {
	cmd \|= PCI_COMMAND_MEMORY;
	pci_write_config_word(pdev, PCI_COMMAND, cmd);
	}

	ret = pci_request_region(pdev, CVP_BAR, "CVP");
	if (ret) {
	dev_err(&pdev->dev, "Requesting CVP BAR region failed\n");
	goto err_disable;
	}

	conf->pci_dev = pdev;
	conf->write_data = altera_cvp_write_data_iomem;

	conf->map = pci_iomap(pdev, CVP_BAR, 0);
	if (!conf->map) {
	dev_warn(&pdev->dev, "Mapping CVP BAR failed\n");
	conf->write_data = altera_cvp_write_data_config;
	}

	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
	ALTERA_CVP_MGR_NAME, pci_name(pdev));

	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
	&altera_cvp_ops, conf);
	if (!mgr) {
	ret = -ENOMEM;
	goto err_unmap;
	}

	pci_set_drvdata(pdev, mgr);

	ret = fpga_mgr_register(mgr);
	if (ret)
	goto err_unmap;

	return 0;

	err_unmap:
	if (conf->map)
	pci_iounmap(pdev, conf->map);
	pci_release_region(pdev, CVP_BAR);
	err_disable:
	cmd &= ~PCI_COMMAND_MEMORY;
	pci_write_config_word(pdev, PCI_COMMAND, cmd);
	return ret;
	}

	static void altera_cvp_remove(struct pci_dev *pdev)
	{
	struct fpga_manager *mgr = pci_get_drvdata(pdev);
	struct altera_cvp_conf *conf = mgr->priv;
	u16 cmd;

	fpga_mgr_unregister(mgr);
	if (conf->map)
	pci_iounmap(pdev, conf->map);
	pci_release_region(pdev, CVP_BAR);
	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
	cmd &= ~PCI_COMMAND_MEMORY;
	pci_write_config_word(pdev, PCI_COMMAND, cmd);
	}

	static int __init altera_cvp_init(void)
	{
	int ret;

	ret = pci_register_driver(&altera_cvp_driver);
	if (ret)
	return ret;

	ret = driver_create_file(&altera_cvp_driver.driver,
	&driver_attr_chkcfg);
	if (ret)
	pr_warn("Can't create sysfs chkcfg file\n");

	return 0;
	}

	static void __exit altera_cvp_exit(void)
	{
	driver_remove_file(&altera_cvp_driver.driver, &driver_attr_chkcfg);
	pci_unregister_driver(&altera_cvp_driver);
	}

	module_init(altera_cvp_init);
	module_exit(altera_cvp_exit);

	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
	MODULE_DESCRIPTION("Module to load Altera FPGA over CvP");