drivers/net/can/esd/esd_402_pci-core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (C) 2015 - 2016 Thomas Körper, esd electronic system design gmbh
  * Copyright (C) 2017 - 2023 Stefan Mätje, esd electronics gmbh
  */

 #include <linux/can/dev.h>
 #include <linux/can.h>
 #include <linux/can/netlink.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/ethtool.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/pci.h>

 #include "esdacc.h"

 #define ESD_PCI_DEVICE_ID_PCIE402 0x0402

 #define PCI402_FPGA_VER_MIN 0x003d
 #define PCI402_MAX_CORES 6
 #define PCI402_BAR 0
 #define PCI402_IO_OV_OFFS 0
 #define PCI402_IO_PCIEP_OFFS 0x10000
 #define PCI402_IO_LEN_TOTAL 0x20000
 #define PCI402_IO_LEN_CORE 0x2000
 #define PCI402_PCICFG_MSICAP 0x50

 #define PCI402_DMA_MASK DMA_BIT_MASK(32)
 #define PCI402_DMA_SIZE ALIGN(0x10000, PAGE_SIZE)

 #define PCI402_PCIEP_OF_INT_ENABLE 0x0050
 #define PCI402_PCIEP_OF_BM_ADDR_LO 0x1000
 #define PCI402_PCIEP_OF_BM_ADDR_HI 0x1004
 #define PCI402_PCIEP_OF_MSI_ADDR_LO 0x1008
 #define PCI402_PCIEP_OF_MSI_ADDR_HI 0x100c

 struct pci402_card {
 	/* Actually mapped io space, all other iomem derived from this */
 	void __iomem *addr;
 	void __iomem *addr_pciep;

 	void *dma_buf;
 	dma_addr_t dma_hnd;

 	struct acc_ov ov;
 	struct acc_core *cores;

 	bool msi_enabled;
 };

 /* The BTR register capabilities described by the can_bittiming_const structures
  * below are valid since esdACC version 0x0032.
  */

 /* Used if the esdACC FPGA is built as CAN-Classic version. */
 static const struct can_bittiming_const pci402_bittiming_const = {
 	.name = "esd_402",
 	.tseg1_min = 1,
 	.tseg1_max = 16,
 	.tseg2_min = 1,
 	.tseg2_max = 8,
 	.sjw_max = 4,
 	.brp_min = 1,
 	.brp_max = 512,
 	.brp_inc = 1,
 };

 /* Used if the esdACC FPGA is built as CAN-FD version. */
 static const struct can_bittiming_const pci402_bittiming_const_canfd = {
 	.name = "esd_402fd",
 	.tseg1_min = 1,
 	.tseg1_max = 256,
 	.tseg2_min = 1,
 	.tseg2_max = 128,
 	.sjw_max = 128,
 	.brp_min = 1,
 	.brp_max = 256,
 	.brp_inc = 1,
 };

 static const struct net_device_ops pci402_acc_netdev_ops = {
 	.ndo_open = acc_open,
 	.ndo_stop = acc_close,
 	.ndo_start_xmit = acc_start_xmit,
 	.ndo_change_mtu = can_change_mtu,
 	.ndo_eth_ioctl = can_eth_ioctl_hwts,
 };

 static const struct ethtool_ops pci402_acc_ethtool_ops = {
 	.get_ts_info = can_ethtool_op_get_ts_info_hwts,
 };

 static irqreturn_t pci402_interrupt(int irq, void *dev_id)
 {
 	struct pci_dev *pdev = dev_id;
 	struct pci402_card *card = pci_get_drvdata(pdev);
 	irqreturn_t irq_status;

 	irq_status = acc_card_interrupt(&card->ov, card->cores);

 	return irq_status;
 }

 static int pci402_set_msiconfig(struct pci_dev *pdev)
 {
 	struct pci402_card *card = pci_get_drvdata(pdev);
 	u32 addr_lo_offs = 0;
 	u32 addr_lo = 0;
 	u32 addr_hi = 0;
 	u32 data = 0;
 	u16 csr = 0;
 	int err;

 	/* The FPGA hard IP PCIe core implements a 64-bit MSI Capability
 	 * Register Format
 	 */
 	err = pci_read_config_word(pdev, PCI402_PCICFG_MSICAP + PCI_MSI_FLAGS, &csr);
 	if (err)
 		goto failed;

 	err = pci_read_config_dword(pdev, PCI402_PCICFG_MSICAP + PCI_MSI_ADDRESS_LO,
 				    &addr_lo);
 	if (err)
 		goto failed;
 	err = pci_read_config_dword(pdev, PCI402_PCICFG_MSICAP + PCI_MSI_ADDRESS_HI,
 				    &addr_hi);
 	if (err)
 		goto failed;

 	err = pci_read_config_dword(pdev, PCI402_PCICFG_MSICAP + PCI_MSI_DATA_64,
 				    &data);
 	if (err)
 		goto failed;

 	addr_lo_offs = addr_lo & 0x0000ffff;
 	addr_lo &= 0xffff0000;

 	if (addr_hi)
 		addr_lo |= 1; /* To enable 64-Bit addressing in PCIe endpoint */

 	if (!(csr & PCI_MSI_FLAGS_ENABLE)) {
 		err = -EINVAL;
 		goto failed;
 	}

 	iowrite32(addr_lo, card->addr_pciep + PCI402_PCIEP_OF_MSI_ADDR_LO);
 	iowrite32(addr_hi, card->addr_pciep + PCI402_PCIEP_OF_MSI_ADDR_HI);
 	acc_ov_write32(&card->ov, ACC_OV_OF_MSI_ADDRESSOFFSET, addr_lo_offs);
 	acc_ov_write32(&card->ov, ACC_OV_OF_MSI_DATA, data);

 	return 0;

 failed:
 	pci_warn(pdev, "Error while setting MSI configuration:\n"
 		 "CSR: 0x%.4x, addr: 0x%.8x%.8x, offs: 0x%.4x, data: 0x%.8x\n",
 		 csr, addr_hi, addr_lo, addr_lo_offs, data);

 	return err;
 }

 static int pci402_init_card(struct pci_dev *pdev)
 {
 	struct pci402_card *card = pci_get_drvdata(pdev);

 	card->ov.addr = card->addr + PCI402_IO_OV_OFFS;
 	card->addr_pciep = card->addr + PCI402_IO_PCIEP_OFFS;

 	acc_reset_fpga(&card->ov);
 	acc_init_ov(&card->ov, &pdev->dev);

 	if (card->ov.version < PCI402_FPGA_VER_MIN) {
 		pci_err(pdev,
 			"esdACC version (0x%.4x) outdated, please update\n",
 			card->ov.version);
 		return -EINVAL;
 	}

 	if (card->ov.timestamp_frequency != ACC_TS_FREQ_80MHZ) {
 		pci_err(pdev,
 			"esdACC timestamp frequency of %uHz not supported by driver. Aborted.\n",
 			card->ov.timestamp_frequency);
 		return -EINVAL;
 	}

 	if (card->ov.active_cores > PCI402_MAX_CORES) {
 		pci_err(pdev,
 			"Card with %u active cores not supported by driver. Aborted.\n",
 			card->ov.active_cores);
 		return -EINVAL;
 	}
 	card->cores = devm_kcalloc(&pdev->dev, card->ov.active_cores,
 				   sizeof(struct acc_core), GFP_KERNEL);
 	if (!card->cores)
 		return -ENOMEM;

 	if (card->ov.features & ACC_OV_REG_FEAT_MASK_CANFD) {
 		pci_warn(pdev,
 			 "esdACC with CAN-FD feature detected. This driver doesn't support CAN-FD yet.\n");
 	}

 #ifdef __LITTLE_ENDIAN
 	/* So card converts all busmastered data to LE for us: */
 	acc_ov_set_bits(&card->ov, ACC_OV_OF_MODE,
 			ACC_OV_REG_MODE_MASK_ENDIAN_LITTLE);
 #endif

 	return 0;
 }

 static int pci402_init_interrupt(struct pci_dev *pdev)
 {
 	struct pci402_card *card = pci_get_drvdata(pdev);
 	int err;

 	err = pci_enable_msi(pdev);
 	if (!err) {
 		err = pci402_set_msiconfig(pdev);
 		if (!err) {
 			card->msi_enabled = true;
 			acc_ov_set_bits(&card->ov, ACC_OV_OF_MODE,
 					ACC_OV_REG_MODE_MASK_MSI_ENABLE);
 			pci_dbg(pdev, "MSI preparation done\n");
 		}
 	}

 	err = devm_request_irq(&pdev->dev, pdev->irq, pci402_interrupt,
 			       IRQF_SHARED, dev_name(&pdev->dev), pdev);
 	if (err)
 		goto failure_msidis;

 	iowrite32(1, card->addr_pciep + PCI402_PCIEP_OF_INT_ENABLE);

 	return 0;

 failure_msidis:
 	if (card->msi_enabled) {
 		acc_ov_clear_bits(&card->ov, ACC_OV_OF_MODE,
 				  ACC_OV_REG_MODE_MASK_MSI_ENABLE);
 		pci_disable_msi(pdev);
 		card->msi_enabled = false;
 	}

 	return err;
 }

 static void pci402_finish_interrupt(struct pci_dev *pdev)
 {
 	struct pci402_card *card = pci_get_drvdata(pdev);

 	iowrite32(0, card->addr_pciep + PCI402_PCIEP_OF_INT_ENABLE);
 	devm_free_irq(&pdev->dev, pdev->irq, pdev);

 	if (card->msi_enabled) {
 		acc_ov_clear_bits(&card->ov, ACC_OV_OF_MODE,
 				  ACC_OV_REG_MODE_MASK_MSI_ENABLE);
 		pci_disable_msi(pdev);
 		card->msi_enabled = false;
 	}
 }

 static int pci402_init_dma(struct pci_dev *pdev)
 {
 	struct pci402_card *card = pci_get_drvdata(pdev);
 	int err;

 	err = dma_set_coherent_mask(&pdev->dev, PCI402_DMA_MASK);
 	if (err) {
 		pci_err(pdev, "DMA set mask failed!\n");
 		return err;
 	}

 	/* The esdACC DMA engine needs the DMA buffer aligned to a 64k
 	 * boundary. The DMA API guarantees to align the returned buffer to the
 	 * smallest PAGE_SIZE order which is greater than or equal to the
 	 * requested size. With PCI402_DMA_SIZE == 64kB this suffices here.
 	 */
 	card->dma_buf = dma_alloc_coherent(&pdev->dev, PCI402_DMA_SIZE,
 					   &card->dma_hnd, GFP_KERNEL);
 	if (!card->dma_buf)
 		return -ENOMEM;

 	acc_init_bm_ptr(&card->ov, card->cores, card->dma_buf);

 	iowrite32(card->dma_hnd,
 		  card->addr_pciep + PCI402_PCIEP_OF_BM_ADDR_LO);
 	iowrite32(0, card->addr_pciep + PCI402_PCIEP_OF_BM_ADDR_HI);

 	pci_set_master(pdev);

 	acc_ov_set_bits(&card->ov, ACC_OV_OF_MODE,
 			ACC_OV_REG_MODE_MASK_BM_ENABLE);

 	return 0;
 }

 static void pci402_finish_dma(struct pci_dev *pdev)
 {
 	struct pci402_card *card = pci_get_drvdata(pdev);
 	int i;

 	acc_ov_clear_bits(&card->ov, ACC_OV_OF_MODE,
 			  ACC_OV_REG_MODE_MASK_BM_ENABLE);

 	pci_clear_master(pdev);

 	iowrite32(0, card->addr_pciep + PCI402_PCIEP_OF_BM_ADDR_LO);
 	iowrite32(0, card->addr_pciep + PCI402_PCIEP_OF_BM_ADDR_HI);

 	card->ov.bmfifo.messages = NULL;
 	card->ov.bmfifo.irq_cnt = NULL;
 	for (i = 0; i < card->ov.active_cores; i++) {
 		struct acc_core *core = &card->cores[i];

 		core->bmfifo.messages = NULL;
 		core->bmfifo.irq_cnt = NULL;
 	}

 	dma_free_coherent(&pdev->dev, PCI402_DMA_SIZE, card->dma_buf,
 			  card->dma_hnd);
 	card->dma_buf = NULL;
 }

 static void pci402_unregister_core(struct acc_core *core)
 {
 	netdev_info(core->netdev, "unregister\n");
 	unregister_candev(core->netdev);

 	free_candev(core->netdev);
 	core->netdev = NULL;
 }

 static int pci402_init_cores(struct pci_dev *pdev)
 {
 	struct pci402_card *card = pci_get_drvdata(pdev);
 	int err;
 	int i;

 	for (i = 0; i < card->ov.active_cores; i++) {
 		struct acc_core *core = &card->cores[i];
 		struct acc_net_priv *priv;
 		struct net_device *netdev;
 		u32 fifo_config;

 		core->addr = card->ov.addr + (i + 1) * PCI402_IO_LEN_CORE;

 		fifo_config = acc_read32(core, ACC_CORE_OF_TXFIFO_CONFIG);
 		core->tx_fifo_size = (fifo_config >> 24);
 		if (core->tx_fifo_size <= 1) {
 			pci_err(pdev, "Invalid tx_fifo_size!\n");
 			err = -EINVAL;
 			goto failure;
 		}

 		netdev = alloc_candev(sizeof(*priv), core->tx_fifo_size);
 		if (!netdev) {
 			err = -ENOMEM;
 			goto failure;
 		}
 		core->netdev = netdev;

 		netdev->flags |= IFF_ECHO;
 		netdev->dev_port = i;
 		netdev->netdev_ops = &pci402_acc_netdev_ops;
 		netdev->ethtool_ops = &pci402_acc_ethtool_ops;
 		SET_NETDEV_DEV(netdev, &pdev->dev);

 		priv = netdev_priv(netdev);
 		priv->can.clock.freq = card->ov.core_frequency;
 		priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 			CAN_CTRLMODE_LISTENONLY |
 			CAN_CTRLMODE_BERR_REPORTING |
 			CAN_CTRLMODE_CC_LEN8_DLC;
 		if (card->ov.features & ACC_OV_REG_FEAT_MASK_DAR)
 			priv->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 		if (card->ov.features & ACC_OV_REG_FEAT_MASK_CANFD)
 			priv->can.bittiming_const = &pci402_bittiming_const_canfd;
 		else
 			priv->can.bittiming_const = &pci402_bittiming_const;
 		priv->can.do_set_bittiming = acc_set_bittiming;
 		priv->can.do_set_mode = acc_set_mode;
 		priv->can.do_get_berr_counter = acc_get_berr_counter;

 		priv->core = core;
 		priv->ov = &card->ov;

 		err = register_candev(netdev);
 		if (err) {
 			free_candev(core->netdev);
 			core->netdev = NULL;
 			goto failure;
 		}

 		netdev_info(netdev, "registered\n");
 	}

 	return 0;

 failure:
 	for (i--; i >= 0; i--)
 		pci402_unregister_core(&card->cores[i]);

 	return err;
 }

 static void pci402_finish_cores(struct pci_dev *pdev)
 {
 	struct pci402_card *card = pci_get_drvdata(pdev);
 	int i;

 	for (i = 0; i < card->ov.active_cores; i++)
 		pci402_unregister_core(&card->cores[i]);
 }

 static int pci402_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	struct pci402_card *card = NULL;
 	int err;

 	err = pci_enable_device(pdev);
 	if (err)
 		return err;

 	card = devm_kzalloc(&pdev->dev, sizeof(*card), GFP_KERNEL);
 	if (!card) {
 		err = -ENOMEM;
 		goto failure_disable_pci;
 	}

 	pci_set_drvdata(pdev, card);

 	err = pci_request_regions(pdev, pci_name(pdev));
 	if (err)
 		goto failure_disable_pci;

 	card->addr = pci_iomap(pdev, PCI402_BAR, PCI402_IO_LEN_TOTAL);
 	if (!card->addr) {
 		err = -ENOMEM;
 		goto failure_release_regions;
 	}

 	err = pci402_init_card(pdev);
 	if (err)
 		goto failure_unmap;

 	err = pci402_init_dma(pdev);
 	if (err)
 		goto failure_unmap;

 	err = pci402_init_interrupt(pdev);
 	if (err)
 		goto failure_finish_dma;

 	err = pci402_init_cores(pdev);
 	if (err)
 		goto failure_finish_interrupt;

 	return 0;

 failure_finish_interrupt:
 	pci402_finish_interrupt(pdev);

 failure_finish_dma:
 	pci402_finish_dma(pdev);

 failure_unmap:
 	pci_iounmap(pdev, card->addr);

 failure_release_regions:
 	pci_release_regions(pdev);

 failure_disable_pci:
 	pci_disable_device(pdev);

 	return err;
 }

 static void pci402_remove(struct pci_dev *pdev)
 {
 	struct pci402_card *card = pci_get_drvdata(pdev);

 	pci402_finish_interrupt(pdev);
 	pci402_finish_cores(pdev);
 	pci402_finish_dma(pdev);
 	pci_iounmap(pdev, card->addr);
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
 }

 static const struct pci_device_id pci402_tbl[] = {
 	{
 		.vendor = PCI_VENDOR_ID_ESDGMBH,
 		.device = ESD_PCI_DEVICE_ID_PCIE402,
 		.subvendor = PCI_VENDOR_ID_ESDGMBH,
 		.subdevice = PCI_ANY_ID,
 	},
 	{ 0, }
 };
 MODULE_DEVICE_TABLE(pci, pci402_tbl);

 static struct pci_driver pci402_driver = {
 	.name = KBUILD_MODNAME,
 	.id_table = pci402_tbl,
 	.probe = pci402_probe,
 	.remove = pci402_remove,
 };
 module_pci_driver(pci402_driver);

 MODULE_DESCRIPTION("Socket-CAN driver for esd CAN 402 card family with esdACC core on PCIe");
 MODULE_AUTHOR("Thomas Körper <socketcan@esd.eu>");
 MODULE_AUTHOR("Stefan Mätje <stefan.maetje@esd.eu>");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/* Copyright (C) 2015 - 2016 Thomas Körper, esd electronic system design gmbh
	* Copyright (C) 2017 - 2023 Stefan Mätje, esd electronics gmbh
	*/

	#include <linux/can/dev.h>
	#include <linux/can.h>
	#include <linux/can/netlink.h>
	#include <linux/delay.h>
	#include <linux/dma-mapping.h>
	#include <linux/ethtool.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/netdevice.h>
	#include <linux/pci.h>

	#include "esdacc.h"

	#define ESD_PCI_DEVICE_ID_PCIE402 0x0402

	#define PCI402_FPGA_VER_MIN 0x003d
	#define PCI402_MAX_CORES 6
	#define PCI402_BAR 0
	#define PCI402_IO_OV_OFFS 0
	#define PCI402_IO_PCIEP_OFFS 0x10000
	#define PCI402_IO_LEN_TOTAL 0x20000
	#define PCI402_IO_LEN_CORE 0x2000
	#define PCI402_PCICFG_MSICAP 0x50

	#define PCI402_DMA_MASK DMA_BIT_MASK(32)
	#define PCI402_DMA_SIZE ALIGN(0x10000, PAGE_SIZE)

	#define PCI402_PCIEP_OF_INT_ENABLE 0x0050
	#define PCI402_PCIEP_OF_BM_ADDR_LO 0x1000
	#define PCI402_PCIEP_OF_BM_ADDR_HI 0x1004
	#define PCI402_PCIEP_OF_MSI_ADDR_LO 0x1008
	#define PCI402_PCIEP_OF_MSI_ADDR_HI 0x100c

	struct pci402_card {
	/* Actually mapped io space, all other iomem derived from this */
	void __iomem *addr;
	void __iomem *addr_pciep;

	void *dma_buf;
	dma_addr_t dma_hnd;

	struct acc_ov ov;
	struct acc_core *cores;

	bool msi_enabled;
	};

	/* The BTR register capabilities described by the can_bittiming_const structures
	* below are valid since esdACC version 0x0032.
	*/

	/* Used if the esdACC FPGA is built as CAN-Classic version. */
	static const struct can_bittiming_const pci402_bittiming_const = {
	.name = "esd_402",
	.tseg1_min = 1,
	.tseg1_max = 16,
	.tseg2_min = 1,
	.tseg2_max = 8,
	.sjw_max = 4,
	.brp_min = 1,
	.brp_max = 512,
	.brp_inc = 1,
	};

	/* Used if the esdACC FPGA is built as CAN-FD version. */
	static const struct can_bittiming_const pci402_bittiming_const_canfd = {
	.name = "esd_402fd",
	.tseg1_min = 1,
	.tseg1_max = 256,
	.tseg2_min = 1,
	.tseg2_max = 128,
	.sjw_max = 128,
	.brp_min = 1,
	.brp_max = 256,
	.brp_inc = 1,
	};

	static const struct net_device_ops pci402_acc_netdev_ops = {
	.ndo_open = acc_open,
	.ndo_stop = acc_close,
	.ndo_start_xmit = acc_start_xmit,
	.ndo_change_mtu = can_change_mtu,
	.ndo_eth_ioctl = can_eth_ioctl_hwts,
	};

	static const struct ethtool_ops pci402_acc_ethtool_ops = {
	.get_ts_info = can_ethtool_op_get_ts_info_hwts,
	};

	static irqreturn_t pci402_interrupt(int irq, void *dev_id)
	{
	struct pci_dev *pdev = dev_id;
	struct pci402_card *card = pci_get_drvdata(pdev);
	irqreturn_t irq_status;

	irq_status = acc_card_interrupt(&card->ov, card->cores);

	return irq_status;
	}

	static int pci402_set_msiconfig(struct pci_dev *pdev)
	{
	struct pci402_card *card = pci_get_drvdata(pdev);
	u32 addr_lo_offs = 0;
	u32 addr_lo = 0;
	u32 addr_hi = 0;
	u32 data = 0;
	u16 csr = 0;
	int err;

	/* The FPGA hard IP PCIe core implements a 64-bit MSI Capability
	* Register Format
	*/
	err = pci_read_config_word(pdev, PCI402_PCICFG_MSICAP + PCI_MSI_FLAGS, &csr);
	if (err)
	goto failed;

	err = pci_read_config_dword(pdev, PCI402_PCICFG_MSICAP + PCI_MSI_ADDRESS_LO,
	&addr_lo);
	if (err)
	goto failed;
	err = pci_read_config_dword(pdev, PCI402_PCICFG_MSICAP + PCI_MSI_ADDRESS_HI,
	&addr_hi);
	if (err)
	goto failed;

	err = pci_read_config_dword(pdev, PCI402_PCICFG_MSICAP + PCI_MSI_DATA_64,
	&data);
	if (err)
	goto failed;

	addr_lo_offs = addr_lo & 0x0000ffff;
	addr_lo &= 0xffff0000;

	if (addr_hi)
	addr_lo \|= 1; /* To enable 64-Bit addressing in PCIe endpoint */

	if (!(csr & PCI_MSI_FLAGS_ENABLE)) {
	err = -EINVAL;
	goto failed;
	}

	iowrite32(addr_lo, card->addr_pciep + PCI402_PCIEP_OF_MSI_ADDR_LO);
	iowrite32(addr_hi, card->addr_pciep + PCI402_PCIEP_OF_MSI_ADDR_HI);
	acc_ov_write32(&card->ov, ACC_OV_OF_MSI_ADDRESSOFFSET, addr_lo_offs);
	acc_ov_write32(&card->ov, ACC_OV_OF_MSI_DATA, data);

	return 0;

	failed:
	pci_warn(pdev, "Error while setting MSI configuration:\n"
	"CSR: 0x%.4x, addr: 0x%.8x%.8x, offs: 0x%.4x, data: 0x%.8x\n",
	csr, addr_hi, addr_lo, addr_lo_offs, data);

	return err;
	}

	static int pci402_init_card(struct pci_dev *pdev)
	{
	struct pci402_card *card = pci_get_drvdata(pdev);

	card->ov.addr = card->addr + PCI402_IO_OV_OFFS;
	card->addr_pciep = card->addr + PCI402_IO_PCIEP_OFFS;

	acc_reset_fpga(&card->ov);
	acc_init_ov(&card->ov, &pdev->dev);

	if (card->ov.version < PCI402_FPGA_VER_MIN) {
	pci_err(pdev,
	"esdACC version (0x%.4x) outdated, please update\n",
	card->ov.version);
	return -EINVAL;
	}

	if (card->ov.timestamp_frequency != ACC_TS_FREQ_80MHZ) {
	pci_err(pdev,
	"esdACC timestamp frequency of %uHz not supported by driver. Aborted.\n",
	card->ov.timestamp_frequency);
	return -EINVAL;
	}

	if (card->ov.active_cores > PCI402_MAX_CORES) {
	pci_err(pdev,
	"Card with %u active cores not supported by driver. Aborted.\n",
	card->ov.active_cores);
	return -EINVAL;
	}
	card->cores = devm_kcalloc(&pdev->dev, card->ov.active_cores,
	sizeof(struct acc_core), GFP_KERNEL);
	if (!card->cores)
	return -ENOMEM;

	if (card->ov.features & ACC_OV_REG_FEAT_MASK_CANFD) {
	pci_warn(pdev,
	"esdACC with CAN-FD feature detected. This driver doesn't support CAN-FD yet.\n");
	}

	#ifdef __LITTLE_ENDIAN
	/* So card converts all busmastered data to LE for us: */
	acc_ov_set_bits(&card->ov, ACC_OV_OF_MODE,
	ACC_OV_REG_MODE_MASK_ENDIAN_LITTLE);
	#endif

	return 0;
	}

	static int pci402_init_interrupt(struct pci_dev *pdev)
	{
	struct pci402_card *card = pci_get_drvdata(pdev);
	int err;

	err = pci_enable_msi(pdev);
	if (!err) {
	err = pci402_set_msiconfig(pdev);
	if (!err) {
	card->msi_enabled = true;
	acc_ov_set_bits(&card->ov, ACC_OV_OF_MODE,
	ACC_OV_REG_MODE_MASK_MSI_ENABLE);
	pci_dbg(pdev, "MSI preparation done\n");
	}
	}

	err = devm_request_irq(&pdev->dev, pdev->irq, pci402_interrupt,
	IRQF_SHARED, dev_name(&pdev->dev), pdev);
	if (err)
	goto failure_msidis;

	iowrite32(1, card->addr_pciep + PCI402_PCIEP_OF_INT_ENABLE);

	return 0;

	failure_msidis:
	if (card->msi_enabled) {
	acc_ov_clear_bits(&card->ov, ACC_OV_OF_MODE,
	ACC_OV_REG_MODE_MASK_MSI_ENABLE);
	pci_disable_msi(pdev);
	card->msi_enabled = false;
	}

	return err;
	}

	static void pci402_finish_interrupt(struct pci_dev *pdev)
	{
	struct pci402_card *card = pci_get_drvdata(pdev);

	iowrite32(0, card->addr_pciep + PCI402_PCIEP_OF_INT_ENABLE);
	devm_free_irq(&pdev->dev, pdev->irq, pdev);

	if (card->msi_enabled) {
	acc_ov_clear_bits(&card->ov, ACC_OV_OF_MODE,
	ACC_OV_REG_MODE_MASK_MSI_ENABLE);
	pci_disable_msi(pdev);
	card->msi_enabled = false;
	}
	}

	static int pci402_init_dma(struct pci_dev *pdev)
	{
	struct pci402_card *card = pci_get_drvdata(pdev);
	int err;

	err = dma_set_coherent_mask(&pdev->dev, PCI402_DMA_MASK);
	if (err) {
	pci_err(pdev, "DMA set mask failed!\n");
	return err;
	}

	/* The esdACC DMA engine needs the DMA buffer aligned to a 64k
	* boundary. The DMA API guarantees to align the returned buffer to the
	* smallest PAGE_SIZE order which is greater than or equal to the
	* requested size. With PCI402_DMA_SIZE == 64kB this suffices here.
	*/
	card->dma_buf = dma_alloc_coherent(&pdev->dev, PCI402_DMA_SIZE,
	&card->dma_hnd, GFP_KERNEL);
	if (!card->dma_buf)
	return -ENOMEM;

	acc_init_bm_ptr(&card->ov, card->cores, card->dma_buf);

	iowrite32(card->dma_hnd,
	card->addr_pciep + PCI402_PCIEP_OF_BM_ADDR_LO);
	iowrite32(0, card->addr_pciep + PCI402_PCIEP_OF_BM_ADDR_HI);

	pci_set_master(pdev);

	acc_ov_set_bits(&card->ov, ACC_OV_OF_MODE,
	ACC_OV_REG_MODE_MASK_BM_ENABLE);

	return 0;
	}

	static void pci402_finish_dma(struct pci_dev *pdev)
	{
	struct pci402_card *card = pci_get_drvdata(pdev);
	int i;

	acc_ov_clear_bits(&card->ov, ACC_OV_OF_MODE,
	ACC_OV_REG_MODE_MASK_BM_ENABLE);

	pci_clear_master(pdev);

	iowrite32(0, card->addr_pciep + PCI402_PCIEP_OF_BM_ADDR_LO);
	iowrite32(0, card->addr_pciep + PCI402_PCIEP_OF_BM_ADDR_HI);

	card->ov.bmfifo.messages = NULL;
	card->ov.bmfifo.irq_cnt = NULL;
	for (i = 0; i < card->ov.active_cores; i++) {
	struct acc_core *core = &card->cores[i];

	core->bmfifo.messages = NULL;
	core->bmfifo.irq_cnt = NULL;
	}

	dma_free_coherent(&pdev->dev, PCI402_DMA_SIZE, card->dma_buf,
	card->dma_hnd);
	card->dma_buf = NULL;
	}

	static void pci402_unregister_core(struct acc_core *core)
	{
	netdev_info(core->netdev, "unregister\n");
	unregister_candev(core->netdev);

	free_candev(core->netdev);
	core->netdev = NULL;
	}

	static int pci402_init_cores(struct pci_dev *pdev)
	{
	struct pci402_card *card = pci_get_drvdata(pdev);
	int err;
	int i;

	for (i = 0; i < card->ov.active_cores; i++) {
	struct acc_core *core = &card->cores[i];
	struct acc_net_priv *priv;
	struct net_device *netdev;
	u32 fifo_config;

	core->addr = card->ov.addr + (i + 1) * PCI402_IO_LEN_CORE;

	fifo_config = acc_read32(core, ACC_CORE_OF_TXFIFO_CONFIG);
	core->tx_fifo_size = (fifo_config >> 24);
	if (core->tx_fifo_size <= 1) {
	pci_err(pdev, "Invalid tx_fifo_size!\n");
	err = -EINVAL;
	goto failure;
	}

	netdev = alloc_candev(sizeof(*priv), core->tx_fifo_size);
	if (!netdev) {
	err = -ENOMEM;
	goto failure;
	}
	core->netdev = netdev;

	netdev->flags \|= IFF_ECHO;
	netdev->dev_port = i;
	netdev->netdev_ops = &pci402_acc_netdev_ops;
	netdev->ethtool_ops = &pci402_acc_ethtool_ops;
	SET_NETDEV_DEV(netdev, &pdev->dev);

	priv = netdev_priv(netdev);
	priv->can.clock.freq = card->ov.core_frequency;
	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK \|
	CAN_CTRLMODE_LISTENONLY \|
	CAN_CTRLMODE_BERR_REPORTING \|
	CAN_CTRLMODE_CC_LEN8_DLC;
	if (card->ov.features & ACC_OV_REG_FEAT_MASK_DAR)
	priv->can.ctrlmode_supported \|= CAN_CTRLMODE_ONE_SHOT;
	if (card->ov.features & ACC_OV_REG_FEAT_MASK_CANFD)
	priv->can.bittiming_const = &pci402_bittiming_const_canfd;
	else
	priv->can.bittiming_const = &pci402_bittiming_const;
	priv->can.do_set_bittiming = acc_set_bittiming;
	priv->can.do_set_mode = acc_set_mode;
	priv->can.do_get_berr_counter = acc_get_berr_counter;

	priv->core = core;
	priv->ov = &card->ov;

	err = register_candev(netdev);
	if (err) {
	free_candev(core->netdev);
	core->netdev = NULL;
	goto failure;
	}

	netdev_info(netdev, "registered\n");
	}

	return 0;

	failure:
	for (i--; i >= 0; i--)
	pci402_unregister_core(&card->cores[i]);

	return err;
	}

	static void pci402_finish_cores(struct pci_dev *pdev)
	{
	struct pci402_card *card = pci_get_drvdata(pdev);
	int i;

	for (i = 0; i < card->ov.active_cores; i++)
	pci402_unregister_core(&card->cores[i]);
	}

	static int pci402_probe(struct pci_dev pdev, const struct pci_device_id ent)
	{
	struct pci402_card *card = NULL;
	int err;

	err = pci_enable_device(pdev);
	if (err)
	return err;

	card = devm_kzalloc(&pdev->dev, sizeof(*card), GFP_KERNEL);
	if (!card) {
	err = -ENOMEM;
	goto failure_disable_pci;
	}

	pci_set_drvdata(pdev, card);

	err = pci_request_regions(pdev, pci_name(pdev));
	if (err)
	goto failure_disable_pci;

	card->addr = pci_iomap(pdev, PCI402_BAR, PCI402_IO_LEN_TOTAL);
	if (!card->addr) {
	err = -ENOMEM;
	goto failure_release_regions;
	}

	err = pci402_init_card(pdev);
	if (err)
	goto failure_unmap;

	err = pci402_init_dma(pdev);
	if (err)
	goto failure_unmap;

	err = pci402_init_interrupt(pdev);
	if (err)
	goto failure_finish_dma;

	err = pci402_init_cores(pdev);
	if (err)
	goto failure_finish_interrupt;

	return 0;

	failure_finish_interrupt:
	pci402_finish_interrupt(pdev);

	failure_finish_dma:
	pci402_finish_dma(pdev);

	failure_unmap:
	pci_iounmap(pdev, card->addr);

	failure_release_regions:
	pci_release_regions(pdev);

	failure_disable_pci:
	pci_disable_device(pdev);

	return err;
	}

	static void pci402_remove(struct pci_dev *pdev)
	{
	struct pci402_card *card = pci_get_drvdata(pdev);

	pci402_finish_interrupt(pdev);
	pci402_finish_cores(pdev);
	pci402_finish_dma(pdev);
	pci_iounmap(pdev, card->addr);
	pci_release_regions(pdev);
	pci_disable_device(pdev);
	}

	static const struct pci_device_id pci402_tbl[] = {
	{
	.vendor = PCI_VENDOR_ID_ESDGMBH,
	.device = ESD_PCI_DEVICE_ID_PCIE402,
	.subvendor = PCI_VENDOR_ID_ESDGMBH,
	.subdevice = PCI_ANY_ID,
	},
	{ 0, }
	};
	MODULE_DEVICE_TABLE(pci, pci402_tbl);

	static struct pci_driver pci402_driver = {
	.name = KBUILD_MODNAME,
	.id_table = pci402_tbl,
	.probe = pci402_probe,
	.remove = pci402_remove,
	};
	module_pci_driver(pci402_driver);

	MODULE_DESCRIPTION("Socket-CAN driver for esd CAN 402 card family with esdACC core on PCIe");
	MODULE_AUTHOR("Thomas Körper <socketcan@esd.eu>");
	MODULE_AUTHOR("Stefan Mätje <stefan.maetje@esd.eu>");
	MODULE_LICENSE("GPL");