[PATCH v8 2/2] can: esd: add support for esd GmbH PCIe/402 CAN interface family

Stefan Mätje
2023-10-25T14:17:00Z

This patch adds support for the PCI based PCIe/402 CAN interface family
from esd GmbH that is available with various form factors
(https://esd.eu/en/products/402-series-can-interfaces).

All boards utilize a FPGA based CAN controller solution developed
by esd (esdACC). For more information on the esdACC see
https://esd.eu/en/products/esdacc.

This driver detects all available CAN interface board variants of
the family but atm. operates the CAN-FD capable devices in
Classic-CAN mode only! A later patch will introduce the CAN-FD
functionality in this driver.

Co-developed-by: Thomas Körper <thomas.koerper@esd.eu>
Signed-off-by: Thomas Körper <thomas.koerper@esd.eu>
Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
---
drivers/net/can/Kconfig | 1 +
drivers/net/can/Makefile | 1 +
drivers/net/can/esd/Kconfig | 12 +
drivers/net/can/esd/Makefile | 7 +
drivers/net/can/esd/esd_402_pci-core.c | 510 ++++++++++++++++
drivers/net/can/esd/esdacc.c | 771 +++++++++++++++++++++++++
drivers/net/can/esd/esdacc.h | 393 +++++++++++++
7 files changed, 1695 insertions(+)
create mode 100644 drivers/net/can/esd/Kconfig
create mode 100644 drivers/net/can/esd/Makefile
create mode 100644 drivers/net/can/esd/esd_402_pci-core.c
create mode 100644 drivers/net/can/esd/esdacc.c
create mode 100644 drivers/net/can/esd/esdacc.h

diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index 649453a3c858..b9a65b44ccef 100644
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -217,6 +217,7 @@ config CAN_XILINXCAN
source "drivers/net/can/c_can/Kconfig"
source "drivers/net/can/cc770/Kconfig"
source "drivers/net/can/ctucanfd/Kconfig"
+source "drivers/net/can/esd/Kconfig"
source "drivers/net/can/ifi_canfd/Kconfig"
source "drivers/net/can/m_can/Kconfig"
source "drivers/net/can/mscan/Kconfig"
diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index ff8f76295d13..4669cd51e7bf 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_CAN_VXCAN) += vxcan.o
obj-$(CONFIG_CAN_SLCAN) += slcan/

obj-y += dev/
+obj-y += esd/
obj-y += rcar/
obj-y += spi/
obj-y += usb/
diff --git a/drivers/net/can/esd/Kconfig b/drivers/net/can/esd/Kconfig
new file mode 100644
index 000000000000..54bfc366634c
--- /dev/null
+++ b/drivers/net/can/esd/Kconfig
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config CAN_ESD_402_PCI
+ tristate "esd electronics gmbh CAN-PCI(e)/402 family"
+ depends on PCI && HAS_DMA
+ help
+ Support for C402 card family from esd electronics gmbh.
+ This card family is based on the ESDACC CAN controller and
+ available in several form factors: PCI, PCIe, PCIe Mini,
+ M.2 PCIe, CPCIserial, PMC, XMC (see https://esd.eu/en)
+
+ This driver can also be built as a module. In this case the
+ module will be called esd_402_pci.
diff --git a/drivers/net/can/esd/Makefile b/drivers/net/can/esd/Makefile
new file mode 100644
index 000000000000..5dd2d470c286
--- /dev/null
+++ b/drivers/net/can/esd/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for esd gmbh ESDACC controller driver
+#
+esd_402_pci-objs := esdacc.o esd_402_pci-core.o
+
+obj-$(CONFIG_CAN_ESD_402_PCI) += esd_402_pci.o
diff --git a/drivers/net/can/esd/esd_402_pci-core.c b/drivers/net/can/esd/esd_402_pci-core.c
new file mode 100644
index 000000000000..84be508c6344
--- /dev/null
+++ b/drivers/net/can/esd/esd_402_pci-core.c
@@ -0,0 +1,510 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2015 - 2016 Thomas Körper, esd electronic system design gmbh
+ * Copyright (C) 2017 - 2022 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/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
+
+/* 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
+};
+
+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;
+};
+
+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 has more active cores (%u) than 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_info(pdev, "MSI enabled\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 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;
+ SET_NETDEV_DEV(netdev, &pdev->dev);
+
+ priv = netdev_priv(netdev);
+ priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+ CAN_CTRLMODE_LISTENONLY |
+ CAN_CTRLMODE_BERR_REPORTING |
+ CAN_CTRLMODE_CC_LEN8_DLC;
+
+ priv->can.clock.freq = card->ov.core_frequency;
+ 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--) {
+ struct acc_core *core = &card->cores[i];
+
+ netdev_info(core->netdev, "unregistering...\n");
+ unregister_candev(core->netdev);
+
+ free_candev(core->netdev);
+ core->netdev = NULL;
+ }
+
+ 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++) {
+ struct acc_core *core = &card->cores[i];
+
+ netdev_info(core->netdev, "unregister\n");
+ unregister_candev(core->netdev);
+
+ free_candev(core->netdev);
+ core->netdev = NULL;
+ }
+}
+
+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)
+ 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");
diff --git a/drivers/net/can/esd/esdacc.c b/drivers/net/can/esd/esdacc.c
new file mode 100644
index 000000000000..49017c986c70
--- /dev/null
+++ b/drivers/net/can/esd/esdacc.c
@@ -0,0 +1,771 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2015 - 2016 Thomas Körper, esd electronic system design gmbh
+ * Copyright (C) 2017 - 2022 Stefan Mätje, esd electronics gmbh
+ */
+
+#include "esdacc.h"
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/ktime.h>
+
+/* ecc value of esdACC equals SJA1000's ECC register */
+#define ACC_ECC_SEG 0x1f
+#define ACC_ECC_DIR 0x20
+#define ACC_ECC_BIT 0x00
+#define ACC_ECC_FORM 0x40
+#define ACC_ECC_STUFF 0x80
+#define ACC_ECC_MASK 0xc0
+
+#define ACC_BM_IRQ_UNMASK_ALL 0x55555555U
+#define ACC_BM_IRQ_MASK_ALL 0xaaaaaaaaU
+#define ACC_BM_IRQ_MASK 0x2U
+#define ACC_BM_IRQ_UNMASK 0x1U
+#define ACC_BM_LENFLAG_TX 0x20
+
+#define ACC_REG_STATUS_IDX_STATUS_DOS 16
+#define ACC_REG_STATUS_IDX_STATUS_ES 17
+#define ACC_REG_STATUS_IDX_STATUS_EP 18
+#define ACC_REG_STATUS_IDX_STATUS_BS 19
+#define ACC_REG_STATUS_IDX_STATUS_RBS 20
+#define ACC_REG_STATUS_IDX_STATUS_RS 21
+#define ACC_REG_STATUS_MASK_STATUS_DOS BIT(ACC_REG_STATUS_IDX_STATUS_DOS)
+#define ACC_REG_STATUS_MASK_STATUS_ES BIT(ACC_REG_STATUS_IDX_STATUS_ES)
+#define ACC_REG_STATUS_MASK_STATUS_EP BIT(ACC_REG_STATUS_IDX_STATUS_EP)
+#define ACC_REG_STATUS_MASK_STATUS_BS BIT(ACC_REG_STATUS_IDX_STATUS_BS)
+#define ACC_REG_STATUS_MASK_STATUS_RBS BIT(ACC_REG_STATUS_IDX_STATUS_RBS)
+#define ACC_REG_STATUS_MASK_STATUS_RS BIT(ACC_REG_STATUS_IDX_STATUS_RS)
+
+static void acc_resetmode_enter(struct acc_core *core)
+{
+ acc_set_bits(core, ACC_CORE_OF_CTRL_MODE,
+ ACC_REG_CONTROL_MASK_MODE_RESETMODE);
+
+ /* Read back reset mode bit to flush PCI write posting */
+ acc_resetmode_entered(core);
+}
+
+static void acc_resetmode_leave(struct acc_core *core)
+{
+ acc_clear_bits(core, ACC_CORE_OF_CTRL_MODE,
+ ACC_REG_CONTROL_MASK_MODE_RESETMODE);
+
+ /* Read back reset mode bit to flush PCI write posting */
+ acc_resetmode_entered(core);
+}
+
+static void acc_txq_put(struct acc_core *core, u32 acc_id, u8 acc_dlc,
+ const void *data)
+{
+ acc_write32_noswap(core, ACC_CORE_OF_TXFIFO_DATA_1,
+ *((const u32 *)(data + 4)));
+ acc_write32_noswap(core, ACC_CORE_OF_TXFIFO_DATA_0,
+ *((const u32 *)data));
+ acc_write32(core, ACC_CORE_OF_TXFIFO_DLC, acc_dlc);
+ /* CAN id must be written at last. This write starts TX. */
+ acc_write32(core, ACC_CORE_OF_TXFIFO_ID, acc_id);
+}
+
+/* Convert timestamp from esdACC time stamp ticks to ns
+ *
+ * The conversion factor ts2ns from time stamp counts to ns is basically
+ * ts2ns = NSEC_PER_SEC / timestamp_frequency
+ *
+ * We handle here only a fixed timestamp frequency of 80MHz. The
+ * resulting ts2ns factor would be 12.5.
+ *
+ * At the end we multiply by 12 and add the half of the HW timestamp
+ * to get a multiplication by 12.5. This way any overflow is
+ * avoided until ktime_t itself overflows.
+ */
+#define ACC_TS_FACTOR (NSEC_PER_SEC / ACC_TS_FREQ_80MHZ)
+#define ACC_TS_80MHZ_SHIFT 1
+
+static ktime_t acc_ts2ktime(struct acc_ov *ov, u64 ts)
+{
+ u64 ns;
+
+ ns = (ts * ACC_TS_FACTOR) + (ts >> ACC_TS_80MHZ_SHIFT);
+
+ return ns_to_ktime(ns);
+}
+
+void acc_init_ov(struct acc_ov *ov, struct device *dev)
+{
+ u32 temp;
+
+ temp = acc_ov_read32(ov, ACC_OV_OF_VERSION);
+ ov->version = temp;
+ ov->features = (temp >> 16);
+
+ temp = acc_ov_read32(ov, ACC_OV_OF_INFO);
+ ov->total_cores = temp;
+ ov->active_cores = (temp >> 8);
+
+ ov->core_frequency = acc_ov_read32(ov, ACC_OV_OF_CANCORE_FREQ);
+ ov->timestamp_frequency = acc_ov_read32(ov, ACC_OV_OF_TS_FREQ_LO);
+
+ /* Depending on ESDACC feature NEW_PSC enable the new prescaler
+ * or adjust core_frequency according to the implicit division by 2.
+ */
+ if (ov->features & ACC_OV_REG_FEAT_MASK_NEW_PSC) {
+ acc_ov_set_bits(ov, ACC_OV_OF_MODE,
+ ACC_OV_REG_MODE_MASK_NEW_PSC_ENABLE);
+ } else {
+ ov->core_frequency /= 2;
+ }
+
+ dev_info(dev,
+ "ESDACC v%u, freq: %u/%u, feat/strap: 0x%x/0x%x, cores: %u/%u\n",
+ ov->version, ov->core_frequency, ov->timestamp_frequency,
+ ov->features, acc_ov_read32(ov, ACC_OV_OF_INFO) >> 16,
+ ov->active_cores, ov->total_cores);
+}
+
+void acc_init_bm_ptr(struct acc_ov *ov, struct acc_core *cores, const void *mem)
+{
+ unsigned int u;
+
+ /* DMA buffer layout as follows where N is the number of CAN cores
+ * implemented in the FPGA, i.e. N = ov->total_cores
+ *
+ * Layout Section size
+ * +-----------------------+
+ * | FIFO Card/Overview | ACC_CORE_DMABUF_SIZE
+ * | |
+ * +-----------------------+
+ * | FIFO Core0 | ACC_CORE_DMABUF_SIZE
+ * | |
+ * +-----------------------+
+ * | ... | ...
+ * | |
+ * +-----------------------+
+ * | FIFO CoreN | ACC_CORE_DMABUF_SIZE
+ * | |
+ * +-----------------------+
+ * | irq_cnt Card/Overview | sizeof(u32)
+ * +-----------------------+
+ * | irq_cnt Core0 | sizeof(u32)
+ * +-----------------------+
+ * | ... | ...
+ * +-----------------------+
+ * | irq_cnt CoreN | sizeof(u32)
+ * +-----------------------+
+ */
+ ov->bmfifo.messages = mem;
+ ov->bmfifo.irq_cnt = mem + (ov->total_cores + 1U) * ACC_CORE_DMABUF_SIZE;
+
+ for (u = 0U; u < ov->active_cores; u++) {
+ struct acc_core *core = &cores[u];
+
+ core->bmfifo.messages = mem + (u + 1U) * ACC_CORE_DMABUF_SIZE;
+ core->bmfifo.irq_cnt = ov->bmfifo.irq_cnt + (u + 1U);
+ }
+}
+
+int acc_open(struct net_device *netdev)
+{
+ struct acc_net_priv *priv = netdev_priv(netdev);
+ struct acc_core *core = priv->core;
+ u32 tx_fifo_status;
+ u32 ctrl_mode;
+ int err;
+
+ /* Retry to enter RESET mode if out of sync. */
+ if (priv->can.state != CAN_STATE_STOPPED) {
+ netdev_warn(netdev, "Entered %s() with bad can.state: %s\n",
+ __func__, can_get_state_str(priv->can.state));
+ acc_resetmode_enter(core);
+ priv->can.state = CAN_STATE_STOPPED;
+ }
+
+ err = open_candev(netdev);
+ if (err)
+ return err;
+
+ ctrl_mode = ACC_REG_CONTROL_MASK_IE_RXTX |
+ ACC_REG_CONTROL_MASK_IE_TXERROR |
+ ACC_REG_CONTROL_MASK_IE_ERRWARN |
+ ACC_REG_CONTROL_MASK_IE_OVERRUN |
+ ACC_REG_CONTROL_MASK_IE_ERRPASS;
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
+ ctrl_mode |= ACC_REG_CONTROL_MASK_IE_BUSERR;
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+ ctrl_mode |= ACC_REG_CONTROL_MASK_MODE_LOM;
+
+ acc_set_bits(core, ACC_CORE_OF_CTRL_MODE, ctrl_mode);
+
+ acc_resetmode_leave(core);
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+ /* Resync TX FIFO indices to HW state after (re-)start. */
+ tx_fifo_status = acc_read32(core, ACC_CORE_OF_TXFIFO_STATUS);
+ core->tx_fifo_head = tx_fifo_status & 0xff;
+ core->tx_fifo_tail = (tx_fifo_status >> 8) & 0xff;
+
+ netif_start_queue(netdev);
+ return 0;
+}
+
+int acc_close(struct net_device *netdev)
+{
+ struct acc_net_priv *priv = netdev_priv(netdev);
+ struct acc_core *core = priv->core;
+
+ acc_clear_bits(core, ACC_CORE_OF_CTRL_MODE,
+ ACC_REG_CONTROL_MASK_IE_RXTX |
+ ACC_REG_CONTROL_MASK_IE_TXERROR |
+ ACC_REG_CONTROL_MASK_IE_ERRWARN |
+ ACC_REG_CONTROL_MASK_IE_OVERRUN |
+ ACC_REG_CONTROL_MASK_IE_ERRPASS |
+ ACC_REG_CONTROL_MASK_IE_BUSERR);
+
+ netif_stop_queue(netdev);
+ acc_resetmode_enter(core);
+ priv->can.state = CAN_STATE_STOPPED;
+
+ /* Mark pending TX requests to be aborted after controller restart. */
+ acc_write32(core, ACC_CORE_OF_TX_ABORT_MASK, 0xffff);
+
+ /* ACC_REG_CONTROL_MASK_MODE_LOM is only accessible in RESET mode */
+ acc_clear_bits(core, ACC_CORE_OF_CTRL_MODE,
+ ACC_REG_CONTROL_MASK_MODE_LOM);
+
+ close_candev(netdev);
+ return 0;
+}
+
+netdev_tx_t acc_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+ struct acc_net_priv *priv = netdev_priv(netdev);
+ struct acc_core *core = priv->core;
+ struct can_frame *cf = (struct can_frame *)skb->data;
+ u8 tx_fifo_head = core->tx_fifo_head;
+ int fifo_usage;
+ u32 acc_id;
+ u8 acc_dlc;
+
+ if (can_dropped_invalid_skb(netdev, skb))
+ return NETDEV_TX_OK;
+
+ /* Access core->tx_fifo_tail only once because it may be changed
+ * from the interrupt level.
+ */
+ fifo_usage = tx_fifo_head - core->tx_fifo_tail;
+ if (fifo_usage < 0)
+ fifo_usage += core->tx_fifo_size;
+
+ if (fifo_usage >= core->tx_fifo_size - 1) {
+ netdev_err(core->netdev,
+ "BUG: TX ring full when queue awake!\n");
+ netif_stop_queue(netdev);
+ return NETDEV_TX_BUSY;
+ }
+
+ if (fifo_usage == core->tx_fifo_size - 2)
+ netif_stop_queue(netdev);
+
+ acc_dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
+ if (cf->can_id & CAN_RTR_FLAG)
+ acc_dlc |= ACC_CAN_RTR_FLAG;
+
+ if (cf->can_id & CAN_EFF_FLAG) {
+ acc_id = cf->can_id & CAN_EFF_MASK;
+ acc_id |= ACC_CAN_EFF_FLAG;
+ } else {
+ acc_id = cf->can_id & CAN_SFF_MASK;
+ }
+
+ can_put_echo_skb(skb, netdev, core->tx_fifo_head, 0);
+
+ tx_fifo_head++;
+ if (tx_fifo_head >= core->tx_fifo_size)
+ tx_fifo_head = 0U;
+ core->tx_fifo_head = tx_fifo_head;
+
+ acc_txq_put(core, acc_id, acc_dlc, cf->data);
+
+ return NETDEV_TX_OK;
+}
+
+int acc_get_berr_counter(const struct net_device *netdev,
+ struct can_berr_counter *bec)
+{
+ struct acc_net_priv *priv = netdev_priv(netdev);
+ u32 core_status = acc_read32(priv->core, ACC_CORE_OF_STATUS);
+
+ bec->txerr = (core_status >> 8) & 0xff;
+ bec->rxerr = core_status & 0xff;
+
+ return 0;
+}
+
+int acc_set_mode(struct net_device *netdev, enum can_mode mode)
+{
+ struct acc_net_priv *priv = netdev_priv(netdev);
+
+ switch (mode) {
+ case CAN_MODE_START:
+ /* Paranoid FIFO index check. */
+ {
+ const u32 tx_fifo_status =
+ acc_read32(priv->core, ACC_CORE_OF_TXFIFO_STATUS);
+ const u8 hw_fifo_head = tx_fifo_status;
+
+ if (hw_fifo_head != priv->core->tx_fifo_head ||
+ hw_fifo_head != priv->core->tx_fifo_tail) {
+ netdev_warn(netdev,
+ "TX FIFO mismatch: T %2u H %2u; TFHW %#08x\n",
+ priv->core->tx_fifo_tail,
+ priv->core->tx_fifo_head,
+ tx_fifo_status);
+ }
+ }
+ acc_resetmode_leave(priv->core);
+ /* To leave the bus-off state the esdACC controller begins
+ * here a grace period where it counts 128 "idle conditions" (each
+ * of 11 consecutive recessive bits) on the bus as required
+ * by the CAN spec.
+ *
+ * During this time the TX FIFO may still contain already
+ * aborted "zombie" frames that are only drained from the FIFO
+ * at the end of the grace period.
+ *
+ * To not to interfere with this drain process we don't
+ * call netif_wake_queue() here. When the controller reaches
+ * the error-active state again, it informs us about that
+ * with an acc_bmmsg_errstatechange message. Then
+ * netif_wake_queue() is called from
+ * handle_core_msg_errstatechange() instead.
+ */
+ break;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+int acc_set_bittiming(struct net_device *netdev)
+{
+ struct acc_net_priv *priv = netdev_priv(netdev);
+ const struct can_bittiming *bt = &priv->can.bittiming;
+ u32 brp;
+ u32 btr;
+
+ if (priv->ov->features & ACC_OV_REG_FEAT_MASK_CANFD) {
+ u32 fbtr = 0;
+
+ netdev_dbg(netdev, "bit timing: brp %u, prop %u, ph1 %u ph2 %u, sjw %u\n",
+ bt->brp, bt->prop_seg,
+ bt->phase_seg1, bt->phase_seg2, bt->sjw);
+
+ brp = FIELD_PREP(ACC_REG_BRP_FD_MASK_BRP, bt->brp - 1);
+
+ btr = FIELD_PREP(ACC_REG_BTR_FD_MASK_TSEG1, bt->phase_seg1 + bt->prop_seg - 1);
+ btr |= FIELD_PREP(ACC_REG_BTR_FD_MASK_TSEG2, bt->phase_seg2 - 1);
+ btr |= FIELD_PREP(ACC_REG_BTR_FD_MASK_SJW, bt->sjw - 1);
+
+ /* Keep order of accesses to ACC_CORE_OF_BRP and ACC_CORE_OF_BTR. */
+ acc_write32(priv->core, ACC_CORE_OF_BRP, brp);
+ acc_write32(priv->core, ACC_CORE_OF_BTR, btr);
+
+ netdev_dbg(netdev, "ESDACC: BRP %u, NBTR 0x%08x, DBTR 0x%08x",
+ brp, btr, fbtr);
+ } else {
+ netdev_dbg(netdev, "bit timing: brp %u, prop %u, ph1 %u ph2 %u, sjw %u\n",
+ bt->brp, bt->prop_seg,
+ bt->phase_seg1, bt->phase_seg2, bt->sjw);
+
+ brp = FIELD_PREP(ACC_REG_BRP_CL_MASK_BRP, bt->brp - 1);
+
+ btr = FIELD_PREP(ACC_REG_BTR_CL_MASK_TSEG1, bt->phase_seg1 + bt->prop_seg - 1);
+ btr |= FIELD_PREP(ACC_REG_BTR_CL_MASK_TSEG2, bt->phase_seg2 - 1);
+ btr |= FIELD_PREP(ACC_REG_BTR_CL_MASK_SJW, bt->sjw - 1);
+
+ /* Keep order of accesses to ACC_CORE_OF_BRP and ACC_CORE_OF_BTR. */
+ acc_write32(priv->core, ACC_CORE_OF_BRP, brp);
+ acc_write32(priv->core, ACC_CORE_OF_BTR, btr);
+
+ netdev_dbg(netdev, "ESDACC: BRP %u, BTR 0x%08x", brp, btr);
+ }
+
+ return 0;
+}
+
+static void handle_core_msg_rxtxdone(struct acc_core *core,
+ const struct acc_bmmsg_rxtxdone *msg)
+{
+ struct acc_net_priv *priv = netdev_priv(core->netdev);
+ struct net_device_stats *stats = &core->netdev->stats;
+ struct sk_buff *skb;
+
+ if (msg->dlc.rxtx.len & ACC_BM_LENFLAG_TX) {
+ u8 tx_fifo_tail = core->tx_fifo_tail;
+
+ if (core->tx_fifo_head == tx_fifo_tail) {
+ netdev_warn(core->netdev,
+ "TX interrupt, but queue is empty!?\n");
+ return;
+ }
+
+ /* Direct access echo skb to attach HW time stamp. */
+ skb = priv->can.echo_skb[tx_fifo_tail];
+ if (skb) {
+ skb_hwtstamps(skb)->hwtstamp =
+ acc_ts2ktime(priv->ov, msg->ts);
+ }
+
+ stats->tx_packets++;
+ stats->tx_bytes += can_get_echo_skb(core->netdev, tx_fifo_tail,
+ NULL);
+
+ tx_fifo_tail++;
+ if (tx_fifo_tail >= core->tx_fifo_size)
+ tx_fifo_tail = 0U;
+ core->tx_fifo_tail = tx_fifo_tail;
+
+ netif_wake_queue(core->netdev);
+
+ } else {
+ struct can_frame *cf;
+
+ skb = alloc_can_skb(core->netdev, &cf);
+ if (!skb) {
+ stats->rx_dropped++;
+ return;
+ }
+
+ cf->can_id = msg->id & CAN_EFF_MASK;
+ if (msg->id & ACC_CAN_EFF_FLAG)
+ cf->can_id |= CAN_EFF_FLAG;
+
+ can_frame_set_cc_len(cf, msg->dlc.rx.len & ACC_CAN_DLC_MASK,
+ priv->can.ctrlmode);
+
+ if (msg->dlc.rx.len & ACC_CAN_RTR_FLAG) {
+ cf->can_id |= CAN_RTR_FLAG;
+ } else {
+ memcpy(cf->data, msg->data, cf->len);
+ stats->rx_bytes += cf->len;
+ }
+ stats->rx_packets++;
+
+ skb_hwtstamps(skb)->hwtstamp = acc_ts2ktime(priv->ov, msg->ts);
+
+ netif_rx(skb);
+ }
+}
+
+static void handle_core_msg_txabort(struct acc_core *core,
+ const struct acc_bmmsg_txabort *msg)
+{
+ struct net_device_stats *stats = &core->netdev->stats;
+ u8 tx_fifo_tail = core->tx_fifo_tail;
+ u32 abort_mask = msg->abort_mask; /* u32 extend to avoid warnings later */
+
+ /* The abort_mask shows which frames were aborted in ESDACC's FIFO. */
+ while (tx_fifo_tail != core->tx_fifo_head && (abort_mask)) {
+ const u32 tail_mask = (1U << tx_fifo_tail);
+
+ if (!(abort_mask & tail_mask))
+ break;
+ abort_mask &= ~tail_mask;
+
+ can_free_echo_skb(core->netdev, tx_fifo_tail, NULL);
+ stats->tx_dropped++;
+ stats->tx_aborted_errors++;
+
+ tx_fifo_tail++;
+ if (tx_fifo_tail >= core->tx_fifo_size)
+ tx_fifo_tail = 0;
+ }
+ core->tx_fifo_tail = tx_fifo_tail;
+ if (abort_mask)
+ netdev_warn(core->netdev, "Unhandled aborted messages\n");
+
+ if (!acc_resetmode_entered(core))
+ netif_wake_queue(core->netdev);
+}
+
+static void handle_core_msg_overrun(struct acc_core *core,
+ const struct acc_bmmsg_overrun *msg)
+{
+ struct acc_net_priv *priv = netdev_priv(core->netdev);
+ struct net_device_stats *stats = &core->netdev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ /* lost_cnt may be 0 if not supported by ESDACC version */
+ if (msg->lost_cnt) {
+ stats->rx_errors += msg->lost_cnt;
+ stats->rx_over_errors += msg->lost_cnt;
+ } else {
+ stats->rx_errors++;
+ stats->rx_over_errors++;
+ }
+
+ skb = alloc_can_err_skb(core->netdev, &cf);
+ if (!skb) {
+ stats->rx_dropped++;
+ return;
+ }
+
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+
+ skb_hwtstamps(skb)->hwtstamp = acc_ts2ktime(priv->ov, msg->ts);
+
+ netif_rx(skb);
+}
+
+static void handle_core_msg_buserr(struct acc_core *core,
+ const struct acc_bmmsg_buserr *msg)
+{
+ struct acc_net_priv *priv = netdev_priv(core->netdev);
+ struct net_device_stats *stats = &core->netdev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+ const u32 reg_status = msg->reg_status;
+ const u8 rxerr = reg_status;
+ const u8 txerr = (reg_status >> 8);
+ u8 can_err_prot_type = 0U;
+
+ priv->can.can_stats.bus_error++;
+
+ /* Error occurred during transmission? */
+ if ((msg->ecc & ACC_ECC_DIR) == 0) {
+ can_err_prot_type |= CAN_ERR_PROT_TX;
+ stats->tx_errors++;
+ } else {
+ stats->rx_errors++;
+ }
+ /* Determine error type */
+ switch (msg->ecc & ACC_ECC_MASK) {
+ case ACC_ECC_BIT:
+ can_err_prot_type |= CAN_ERR_PROT_BIT;
+ break;
+ case ACC_ECC_FORM:
+ can_err_prot_type |= CAN_ERR_PROT_FORM;
+ break;
+ case ACC_ECC_STUFF:
+ can_err_prot_type |= CAN_ERR_PROT_STUFF;
+ break;
+ default:
+ can_err_prot_type |= CAN_ERR_PROT_UNSPEC;
+ break;
+ }
+
+ skb = alloc_can_err_skb(core->netdev, &cf);
+ if (!skb) {
+ stats->rx_dropped++;
+ return;
+ }
+
+ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+ /* Set protocol error type */
+ cf->data[2] = can_err_prot_type;
+ /* Set error location */
+ cf->data[3] = msg->ecc & ACC_ECC_SEG;
+
+ /* Insert CAN TX and RX error counters. */
+ cf->data[6] = txerr;
+ cf->data[7] = rxerr;
+
+ skb_hwtstamps(skb)->hwtstamp = acc_ts2ktime(priv->ov, msg->ts);
+
+ netif_rx(skb);
+}
+
+static void
+handle_core_msg_errstatechange(struct acc_core *core,
+ const struct acc_bmmsg_errstatechange *msg)
+{
+ struct acc_net_priv *priv = netdev_priv(core->netdev);
+ struct net_device_stats *stats = &core->netdev->stats;
+ struct can_frame *cf = NULL;
+ struct sk_buff *skb;
+ const u32 reg_status = msg->reg_status;
+ const u8 rxerr = reg_status;
+ const u8 txerr = (reg_status >> 8);
+ enum can_state new_state;
+
+ if (reg_status & ACC_REG_STATUS_MASK_STATUS_BS) {
+ new_state = CAN_STATE_BUS_OFF;
+ } else if (reg_status & ACC_REG_STATUS_MASK_STATUS_EP) {
+ new_state = CAN_STATE_ERROR_PASSIVE;
+ } else if (reg_status & ACC_REG_STATUS_MASK_STATUS_ES) {
+ new_state = CAN_STATE_ERROR_WARNING;
+ } else {
+ new_state = CAN_STATE_ERROR_ACTIVE;
+ if (priv->can.state == CAN_STATE_BUS_OFF) {
+ /* See comment in acc_set_mode() for CAN_MODE_START */
+ netif_wake_queue(core->netdev);
+ }
+ }
+
+ skb = alloc_can_err_skb(core->netdev, &cf);
+
+ if (new_state != priv->can.state) {
+ enum can_state tx_state, rx_state;
+
+ tx_state = (txerr >= rxerr) ?
+ new_state : CAN_STATE_ERROR_ACTIVE;
+ rx_state = (rxerr >= txerr) ?
+ new_state : CAN_STATE_ERROR_ACTIVE;
+
+ /* Always call can_change_state() to update the state
+ * even if alloc_can_err_skb() may have failed.
+ * can_change_state() can cope with a NULL cf pointer.
+ */
+ can_change_state(core->netdev, cf, tx_state, rx_state);
+ }
+
+ if (skb) {
+ cf->data[6] = txerr;
+ cf->data[7] = rxerr;
+
+ skb_hwtstamps(skb)->hwtstamp = acc_ts2ktime(priv->ov, msg->ts);
+
+ netif_rx(skb);
+ } else {
+ stats->rx_dropped++;
+ }
+
+ if (new_state == CAN_STATE_BUS_OFF) {
+ acc_write32(core, ACC_CORE_OF_TX_ABORT_MASK, 0xffff);
+ can_bus_off(core->netdev);
+ }
+}
+
+static void handle_core_interrupt(struct acc_core *core)
+{
+ u32 msg_fifo_head = core->bmfifo.local_irq_cnt & 0xff;
+
+ while (core->bmfifo.msg_fifo_tail != msg_fifo_head) {
+ const union acc_bmmsg *msg =
+ &core->bmfifo.messages[core->bmfifo.msg_fifo_tail];
+
+ switch (msg->msg_id) {
+ case BM_MSG_ID_RXTXDONE:
+ handle_core_msg_rxtxdone(core, &msg->rxtxdone);
+ break;
+
+ case BM_MSG_ID_TXABORT:
+ handle_core_msg_txabort(core, &msg->txabort);
+ break;
+
+ case BM_MSG_ID_OVERRUN:
+ handle_core_msg_overrun(core, &msg->overrun);
+ break;
+
+ case BM_MSG_ID_BUSERR:
+ handle_core_msg_buserr(core, &msg->buserr);
+ break;
+
+ case BM_MSG_ID_ERRPASSIVE:
+ case BM_MSG_ID_ERRWARN:
+ handle_core_msg_errstatechange(core,
+ &msg->errstatechange);
+ break;
+
+ default:
+ /* Ignore all other BM messages (like the CAN-FD messages) */
+ break;
+ }
+
+ core->bmfifo.msg_fifo_tail =
+ (core->bmfifo.msg_fifo_tail + 1) & 0xff;
+ }
+}
+
+/**
+ * acc_card_interrupt() - handle the interrupts of an esdACC FPGA
+ *
+ * @ov: overview module structure
+ * @cores: array of core structures
+ *
+ * This function handles all interrupts pending for the overview module and the
+ * CAN cores of the esdACC FPGA.
+ *
+ * It examines for all cores (the overview module core and the CAN cores)
+ * the bmfifo.irq_cnt and compares it with the previously saved
+ * bmfifo.local_irq_cnt. An IRQ is pending if they differ. The esdACC FPGA
+ * updates the bmfifo.irq_cnt values by DMA.
+ *
+ * The pending interrupts are masked by writing to the IRQ mask register at
+ * ACC_OV_OF_BM_IRQ_MASK. This register has for each core a two bit command
+ * field evaluated as follows:
+ *
+ * Define, bit pattern: meaning
+ * 00: no action
+ * ACC_BM_IRQ_UNMASK, 01: unmask interrupt
+ * ACC_BM_IRQ_MASK, 10: mask interrupt
+ * 11: no action
+ *
+ * For each CAN core with a pending IRQ handle_core_interrupt() handles all
+ * busmaster messages from the message FIFO. The last handled message (FIFO
+ * index) is written to the CAN core to acknowledge its handling.
+ *
+ * Last step is to unmask all interrupts in the FPGA using
+ * ACC_BM_IRQ_UNMASK_ALL.
+ */
+irqreturn_t acc_card_interrupt(struct acc_ov *ov, struct acc_core *cores)
+{
+ u32 irqmask;
+ int i;
+
+ /* First we look for whom interrupts are pending, card/overview
+ * or any of the cores. Two bits in irqmask are used for each;
+ * Each two bit field is set to ACC_BM_IRQ_MASK if an IRQ is
+ * pending.
+ */
+ irqmask = 0;
+ if (READ_ONCE(*ov->bmfifo.irq_cnt) != ov->bmfifo.local_irq_cnt) {
+ irqmask |= ACC_BM_IRQ_MASK;
+ ov->bmfifo.local_irq_cnt = READ_ONCE(*ov->bmfifo.irq_cnt);
+ }
+
+ for (i = 0; i < ov->active_cores; i++) {
+ struct acc_core *core = &cores[i];
+
+ if (READ_ONCE(*core->bmfifo.irq_cnt) != core->bmfifo.local_irq_cnt) {
+ irqmask |= (ACC_BM_IRQ_MASK << (2 * (i + 1)));
+ core->bmfifo.local_irq_cnt = READ_ONCE(*core->bmfifo.irq_cnt);
+ }
+ }
+
+ if (!irqmask)
+ return IRQ_NONE;
+
+ /* At second we tell the card we're working on them by writing irqmask,
+ * call handle_{ov|core}_interrupt and then acknowledge the
+ * interrupts by writing irq_cnt:
+ */
+ acc_ov_write32(ov, ACC_OV_OF_BM_IRQ_MASK, irqmask);
+
+ if (irqmask & ACC_BM_IRQ_MASK) {
+ /* handle_ov_interrupt(); - no use yet. */
+ acc_ov_write32(ov, ACC_OV_OF_BM_IRQ_COUNTER,
+ ov->bmfifo.local_irq_cnt);
+ }
+
+ for (i = 0; i < ov->active_cores; i++) {
+ struct acc_core *core = &cores[i];
+
+ if (irqmask & (ACC_BM_IRQ_MASK << (2 * (i + 1)))) {
+ handle_core_interrupt(core);
+ acc_write32(core, ACC_OV_OF_BM_IRQ_COUNTER,
+ core->bmfifo.local_irq_cnt);
+ }
+ }
+
+ acc_ov_write32(ov, ACC_OV_OF_BM_IRQ_MASK, ACC_BM_IRQ_UNMASK_ALL);
+
+ return IRQ_HANDLED;
+}
diff --git a/drivers/net/can/esd/esdacc.h b/drivers/net/can/esd/esdacc.h
new file mode 100644
index 000000000000..73651bc1d52c
--- /dev/null
+++ b/drivers/net/can/esd/esdacc.h
@@ -0,0 +1,393 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) 2015 - 2016 Thomas Körper, esd electronic system design gmbh
+ * Copyright (C) 2017 - 2022 Stefan Mätje, esd electronics gmbh
+ */
+
+#include <linux/bits.h>
+#include <linux/can/dev.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/units.h>
+
+#define ACC_TS_FREQ_80MHZ (80 * HZ_PER_MHZ)
+
+#define ACC_CAN_EFF_FLAG 0x20000000
+#define ACC_CAN_RTR_FLAG 0x10
+#define ACC_CAN_DLC_MASK 0x0f
+
+#define ACC_OV_OF_PROBE 0x0000
+#define ACC_OV_OF_VERSION 0x0004
+#define ACC_OV_OF_INFO 0x0008
+#define ACC_OV_OF_CANCORE_FREQ 0x000c
+#define ACC_OV_OF_TS_FREQ_LO 0x0010
+#define ACC_OV_OF_TS_FREQ_HI 0x0014
+#define ACC_OV_OF_IRQ_STATUS_CORES 0x0018
+#define ACC_OV_OF_TS_CURR_LO 0x001c
+#define ACC_OV_OF_TS_CURR_HI 0x0020
+#define ACC_OV_OF_IRQ_STATUS 0x0028
+#define ACC_OV_OF_MODE 0x002c
+#define ACC_OV_OF_BM_IRQ_COUNTER 0x0070
+#define ACC_OV_OF_BM_IRQ_MASK 0x0074
+#define ACC_OV_OF_MSI_DATA 0x0080
+#define ACC_OV_OF_MSI_ADDRESSOFFSET 0x0084
+
+/* Feature flags are contained in the upper 16 bit of the version
+ * register at ACC_OV_OF_VERSION but only used with these masks after
+ * extraction into an extra variable => (xx - 16).
+ */
+#define ACC_OV_REG_FEAT_IDX_CANFD (27 - 16)
+#define ACC_OV_REG_FEAT_IDX_NEW_PSC (28 - 16)
+#define ACC_OV_REG_FEAT_MASK_CANFD BIT(ACC_OV_REG_FEAT_IDX_CANFD)
+#define ACC_OV_REG_FEAT_MASK_NEW_PSC BIT(ACC_OV_REG_FEAT_IDX_NEW_PSC)
+
+#define ACC_OV_REG_MODE_MASK_ENDIAN_LITTLE 0x00000001
+#define ACC_OV_REG_MODE_MASK_BM_ENABLE 0x00000002
+#define ACC_OV_REG_MODE_MASK_MODE_LED 0x00000004
+#define ACC_OV_REG_MODE_MASK_TIMER 0x00000070
+#define ACC_OV_REG_MODE_MASK_TIMER_ENABLE 0x00000010
+#define ACC_OV_REG_MODE_MASK_TIMER_ONE_SHOT 0x00000020
+#define ACC_OV_REG_MODE_MASK_TIMER_ABSOLUTE 0x00000040
+#define ACC_OV_REG_MODE_MASK_TS_SRC 0x00000180
+#define ACC_OV_REG_MODE_MASK_I2C_ENABLE 0x00000800
+#define ACC_OV_REG_MODE_MASK_MSI_ENABLE 0x00004000
+#define ACC_OV_REG_MODE_MASK_NEW_PSC_ENABLE 0x00008000
+#define ACC_OV_REG_MODE_MASK_FPGA_RESET 0x80000000
+
+#define ACC_CORE_OF_CTRL_MODE 0x0000
+#define ACC_CORE_OF_STATUS_IRQ 0x0008
+#define ACC_CORE_OF_BRP 0x000c
+#define ACC_CORE_OF_BTR 0x0010
+#define ACC_CORE_OF_FBTR 0x0014
+#define ACC_CORE_OF_STATUS 0x0030
+#define ACC_CORE_OF_TXFIFO_CONFIG 0x0048
+#define ACC_CORE_OF_TXFIFO_STATUS 0x004c
+#define ACC_CORE_OF_TX_STATUS_IRQ 0x0050
+#define ACC_CORE_OF_TX_ABORT_MASK 0x0054
+#define ACC_CORE_OF_BM_IRQ_COUNTER 0x0070
+#define ACC_CORE_OF_TXFIFO_ID 0x00c0
+#define ACC_CORE_OF_TXFIFO_DLC 0x00c4
+#define ACC_CORE_OF_TXFIFO_DATA_0 0x00c8
+#define ACC_CORE_OF_TXFIFO_DATA_1 0x00cc
+
+#define ACC_REG_CONTROL_IDX_MODE_RESETMODE 0
+#define ACC_REG_CONTROL_IDX_MODE_LOM 1
+#define ACC_REG_CONTROL_IDX_MODE_STM 2
+#define ACC_REG_CONTROL_IDX_MODE_TRANSEN 5
+#define ACC_REG_CONTROL_IDX_MODE_TS 6
+#define ACC_REG_CONTROL_IDX_MODE_SCHEDULE 7
+#define ACC_REG_CONTROL_MASK_MODE_RESETMODE \
+ BIT(ACC_REG_CONTROL_IDX_MODE_RESETMODE)
+#define ACC_REG_CONTROL_MASK_MODE_LOM \
+ BIT(ACC_REG_CONTROL_IDX_MODE_LOM)
+#define ACC_REG_CONTROL_MASK_MODE_STM \
+ BIT(ACC_REG_CONTROL_IDX_MODE_STM)
+#define ACC_REG_CONTROL_MASK_MODE_TRANSEN \
+ BIT(ACC_REG_CONTROL_IDX_MODE_TRANSEN)
+#define ACC_REG_CONTROL_MASK_MODE_TS \
+ BIT(ACC_REG_CONTROL_IDX_MODE_TS)
+#define ACC_REG_CONTROL_MASK_MODE_SCHEDULE \
+ BIT(ACC_REG_CONTROL_IDX_MODE_SCHEDULE)
+
+#define ACC_REG_CONTROL_IDX_IE_RXTX 8
+#define ACC_REG_CONTROL_IDX_IE_TXERROR 9
+#define ACC_REG_CONTROL_IDX_IE_ERRWARN 10
+#define ACC_REG_CONTROL_IDX_IE_OVERRUN 11
+#define ACC_REG_CONTROL_IDX_IE_TSI 12
+#define ACC_REG_CONTROL_IDX_IE_ERRPASS 13
+#define ACC_REG_CONTROL_IDX_IE_BUSERR 15
+#define ACC_REG_CONTROL_MASK_IE_RXTX BIT(ACC_REG_CONTROL_IDX_IE_RXTX)
+#define ACC_REG_CONTROL_MASK_IE_TXERROR BIT(ACC_REG_CONTROL_IDX_IE_TXERROR)
+#define ACC_REG_CONTROL_MASK_IE_ERRWARN BIT(ACC_REG_CONTROL_IDX_IE_ERRWARN)
+#define ACC_REG_CONTROL_MASK_IE_OVERRUN BIT(ACC_REG_CONTROL_IDX_IE_OVERRUN)
+#define ACC_REG_CONTROL_MASK_IE_TSI BIT(ACC_REG_CONTROL_IDX_IE_TSI)
+#define ACC_REG_CONTROL_MASK_IE_ERRPASS BIT(ACC_REG_CONTROL_IDX_IE_ERRPASS)
+#define ACC_REG_CONTROL_MASK_IE_BUSERR BIT(ACC_REG_CONTROL_IDX_IE_BUSERR)
+
+/* BRP and BTR register layout for CAN-Classic version */
+#define ACC_REG_BRP_CL_MASK_BRP GENMASK(8, 0)
+#define ACC_REG_BTR_CL_MASK_TSEG1 GENMASK(3, 0)
+#define ACC_REG_BTR_CL_MASK_TSEG2 GENMASK(18, 16)
+#define ACC_REG_BTR_CL_MASK_SJW GENMASK(25, 24)
+
+/* BRP and BTR register layout for CAN-FD version */
+#define ACC_REG_BRP_FD_MASK_BRP GENMASK(7, 0)
+#define ACC_REG_BTR_FD_MASK_TSEG1 GENMASK(7, 0)
+#define ACC_REG_BTR_FD_MASK_TSEG2 GENMASK(22, 16)
+#define ACC_REG_BTR_FD_MASK_SJW GENMASK(30, 24)
+
+/* 256 BM_MSGs of 32 byte size */
+#define ACC_CORE_DMAMSG_SIZE 32U
+#define ACC_CORE_DMABUF_SIZE (256U * ACC_CORE_DMAMSG_SIZE)
+
+enum acc_bmmsg_id {
+ BM_MSG_ID_RXTXDONE = 0x01,
+ BM_MSG_ID_TXABORT = 0x02,
+ BM_MSG_ID_OVERRUN = 0x03,
+ BM_MSG_ID_BUSERR = 0x04,
+ BM_MSG_ID_ERRPASSIVE = 0x05,
+ BM_MSG_ID_ERRWARN = 0x06,
+ BM_MSG_ID_TIMESLICE = 0x07,
+ BM_MSG_ID_HWTIMER = 0x08,
+ BM_MSG_ID_HOTPLUG = 0x09,
+};
+
+/* The struct acc_bmmsg_* structure declarations that follow here provide
+ * access to the ring buffer of bus master messages maintained by the FPGA
+ * bus master engine. All bus master messages have the same size of
+ * ACC_CORE_DMAMSG_SIZE and a minimum alignment of ACC_CORE_DMAMSG_SIZE in
+ * memory.
+ *
+ * All structure members are natural aligned. Therefore we should not need
+ * a __packed attribute. All struct acc_bmmsg_* declarations have at least
+ * reserved* members to fill the structure to the full ACC_CORE_DMAMSG_SIZE.
+ *
+ * A failure of this property due padding will be detected at compile time
+ * by static_assert(sizeof(union acc_bmmsg) == ACC_CORE_DMAMSG_SIZE).
+ */
+
+struct acc_bmmsg_rxtxdone {
+ u8 msg_id;
+ u8 txfifo_level;
+ u8 reserved1[2];
+ u8 txtsfifo_level;
+ u8 reserved2[3];
+ u32 id;
+ union {
+ struct {
+ u8 len;
+ u8 reserved0;
+ u8 bits;
+ u8 state;
+ } rxtx;
+ struct {
+ u8 len;
+ u8 msg_lost;
+ u8 bits;
+ u8 state;
+ } rx;
+ struct {
+ u8 len;
+ u8 txfifo_idx;
+ u8 bits;
+ u8 state;
+ } tx;
+ } dlc;
+ u8 data[8];
+ /* Time stamps in struct acc_ov::timestamp_frequency ticks. */
+ u64 ts;
+};
+
+struct acc_bmmsg_txabort {
+ u8 msg_id;
+ u8 txfifo_level;
+ u16 abort_mask;
+ u8 txtsfifo_level;
+ u8 reserved2[1];
+ u16 abort_mask_txts;
+ u64 ts;
+ u32 reserved3[4];
+};
+
+struct acc_bmmsg_overrun {
+ u8 msg_id;
+ u8 txfifo_level;
+ u8 lost_cnt;
+ u8 reserved1;
+ u8 txtsfifo_level;
+ u8 reserved2[3];
+ u64 ts;
+ u32 reserved3[4];
+};
+
+struct acc_bmmsg_buserr {
+ u8 msg_id;
+ u8 txfifo_level;
+ u8 ecc;
+ u8 reserved1;
+ u8 txtsfifo_level;
+ u8 reserved2[3];
+ u64 ts;
+ u32 reg_status;
+ u32 reg_btr;
+ u32 reserved3[2];
+};
+
+struct acc_bmmsg_errstatechange {
+ u8 msg_id;
+ u8 txfifo_level;
+ u8 reserved1[2];
+ u8 txtsfifo_level;
+ u8 reserved2[3];
+ u64 ts;
+ u32 reg_status;
+ u32 reserved3[3];
+};
+
+struct acc_bmmsg_timeslice {
+ u8 msg_id;
+ u8 txfifo_level;
+ u8 reserved1[2];
+ u8 txtsfifo_level;
+ u8 reserved2[3];
+ u64 ts;
+ u32 reserved3[4];
+};
+
+struct acc_bmmsg_hwtimer {
+ u8 msg_id;
+ u8 reserved1[3];
+ u32 reserved2[1];
+ u64 timer;
+ u32 reserved3[4];
+};
+
+struct acc_bmmsg_hotplug {
+ u8 msg_id;
+ u8 reserved1[3];
+ u32 reserved2[7];
+};
+
+union acc_bmmsg {
+ u8 msg_id;
+ struct acc_bmmsg_rxtxdone rxtxdone;
+ struct acc_bmmsg_txabort txabort;
+ struct acc_bmmsg_overrun overrun;
+ struct acc_bmmsg_buserr buserr;
+ struct acc_bmmsg_errstatechange errstatechange;
+ struct acc_bmmsg_timeslice timeslice;
+ struct acc_bmmsg_hwtimer hwtimer;
+};
+
+/* Check size of union acc_bmmsg to be of expected size. */
+static_assert(sizeof(union acc_bmmsg) == ACC_CORE_DMAMSG_SIZE);
+
+struct acc_bmfifo {
+ const union acc_bmmsg *messages;
+ /* irq_cnt points to an u32 value where the ESDACC FPGA deposits
+ * the bm_fifo head index in coherent DMA memory. Only bits 7..0
+ * are valid. Use READ_ONCE() to access this memory location.
+ */
+ const u32 *irq_cnt;
+ u32 local_irq_cnt;
+ u32 msg_fifo_tail;
+};
+
+struct acc_core {
+ void __iomem *addr;
+ struct net_device *netdev;
+ struct acc_bmfifo bmfifo;
+ u8 tx_fifo_size;
+ u8 tx_fifo_head;
+ u8 tx_fifo_tail;
+};
+
+struct acc_ov {
+ void __iomem *addr;
+ struct acc_bmfifo bmfifo;
+ u32 timestamp_frequency;
+ u32 core_frequency;
+ u16 version;
+ u16 features;
+ u8 total_cores;
+ u8 active_cores;
+};
+
+struct acc_net_priv {
+ struct can_priv can; /* must be the first member! */
+ struct acc_core *core;
+ struct acc_ov *ov;
+};
+
+static inline u32 acc_read32(struct acc_core *core, unsigned short offs)
+{
+ return ioread32be(core->addr + offs);
+}
+
+static inline void acc_write32(struct acc_core *core,
+ unsigned short offs, u32 v)
+{
+ iowrite32be(v, core->addr + offs);
+}
+
+static inline void acc_write32_noswap(struct acc_core *core,
+ unsigned short offs, u32 v)
+{
+ iowrite32(v, core->addr + offs);
+}
+
+static inline void acc_set_bits(struct acc_core *core,
+ unsigned short offs, u32 mask)
+{
+ u32 v = acc_read32(core, offs);
+
+ v |= mask;
+ acc_write32(core, offs, v);
+}
+
+static inline void acc_clear_bits(struct acc_core *core,
+ unsigned short offs, u32 mask)
+{
+ u32 v = acc_read32(core, offs);
+
+ v &= ~mask;
+ acc_write32(core, offs, v);
+}
+
+static inline int acc_resetmode_entered(struct acc_core *core)
+{
+ u32 ctrl = acc_read32(core, ACC_CORE_OF_CTRL_MODE);
+
+ return (ctrl & ACC_REG_CONTROL_MASK_MODE_RESETMODE) != 0;
+}
+
+static inline u32 acc_ov_read32(struct acc_ov *ov, unsigned short offs)
+{
+ return ioread32be(ov->addr + offs);
+}
+
+static inline void acc_ov_write32(struct acc_ov *ov,
+ unsigned short offs, u32 v)
+{
+ iowrite32be(v, ov->addr + offs);
+}
+
+static inline void acc_ov_set_bits(struct acc_ov *ov,
+ unsigned short offs, u32 b)
+{
+ u32 v = acc_ov_read32(ov, offs);
+
+ v |= b;
+ acc_ov_write32(ov, offs, v);
+}
+
+static inline void acc_ov_clear_bits(struct acc_ov *ov,
+ unsigned short offs, u32 b)
+{
+ u32 v = acc_ov_read32(ov, offs);
+
+ v &= ~b;
+ acc_ov_write32(ov, offs, v);
+}
+
+static inline void acc_reset_fpga(struct acc_ov *ov)
+{
+ acc_ov_write32(ov, ACC_OV_OF_MODE, ACC_OV_REG_MODE_MASK_FPGA_RESET);
+
+ /* Also reset I^2C, to re-detect card addons at every driver start: */
+ acc_ov_clear_bits(ov, ACC_OV_OF_MODE, ACC_OV_REG_MODE_MASK_I2C_ENABLE);
+ mdelay(2);
+ acc_ov_set_bits(ov, ACC_OV_OF_MODE, ACC_OV_REG_MODE_MASK_I2C_ENABLE);
+ mdelay(10);
+}
+
+void acc_init_ov(struct acc_ov *ov, struct device *dev);
+void acc_init_bm_ptr(struct acc_ov *ov, struct acc_core *cores,
+ const void *mem);
+int acc_open(struct net_device *netdev);
+int acc_close(struct net_device *netdev);
+netdev_tx_t acc_start_xmit(struct sk_buff *skb, struct net_device *netdev);
+int acc_get_berr_counter(const struct net_device *netdev,
+ struct can_berr_counter *bec);
+int acc_set_mode(struct net_device *netdev, enum can_mode mode);
+int acc_set_bittiming(struct net_device *netdev);
+irqreturn_t acc_card_interrupt(struct acc_ov *ov, struct acc_core *cores);
--
2.25.1