Re: [PATCH v10 2/2] can: esd: add support for esd GmbH PCIe/402 CAN interface family
From: Stefan Mätje <Stefan.Maetje@esd.eu>
Date: 2023-11-22 15:43:48
Also in:
linux-can, lkml
Will change the patch to follow your last comment below. Am Mittwoch, den 22.11.2023, 00:04 +0900 schrieb Vincent Mailhol:
Two last comments. These are not withstanding. On Tue. 21 Nov. 2023 at 02:57, Stefan Mätje [off-list ref] wrote:quoted
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 <redacted> Signed-off-by: Thomas Körper <redacted> Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu> ---(...)quoted
diff --git a/drivers/net/can/esd/esdacc.c b/drivers/net/can/esd/esdacc.c new file mode 100644 index 000000000000..c990e60c09f1 --- /dev/null +++ b/drivers/net/can/esd/esdacc.c@@ -0,0 +1,761 @@ +// 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 "esdacc.h" + +#include <linux/bitfield.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/ktime.h> + +/* esdACC ID register layout */ +#define ACC_ID_ID_MASK GENMASK(28, 0) +#define ACC_ID_EFF_FLAG BIT(29) + +/* esdACC DLC register layout */ +#define ACC_DLC_DLC_MASK GENMASK(3, 0) +#define ACC_DLC_RTR_FLAG BIT(4) +#define ACC_DLC_TXD_FLAG BIT(5) + +/* 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 + +/* esdACC Status Register bits. Unused bits not documented. */ +#define ACC_REG_STATUS_MASK_STATUS_ES BIT(17) +#define ACC_REG_STATUS_MASK_STATUS_EP BIT(18) +#define ACC_REG_STATUS_MASK_STATUS_BS BIT(19) + +/* esdACC Overview Module BM_IRQ_Mask register related defines */ +/* Two bit wide command masks to mask or unmask a single core IRQ */ +#define ACC_BM_IRQ_UNMASK BIT(0) +#define ACC_BM_IRQ_MASK (ACC_BM_IRQ_UNMASK << 1) +/* Command to unmask all IRQ sources. Created by shifting + * and oring the two bit wide ACC_BM_IRQ_UNMASK 16 times. + */ +#define ACC_BM_IRQ_UNMASK_ALL 0x55555555U + +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); +} + +static u8 acc_tx_fifo_next(struct acc_core *core, u8 tx_fifo_idx) +{ + ++tx_fifo_idx; + if (tx_fifo_idx >= core->tx_fifo_size) + tx_fifo_idx = 0U; + return tx_fifo_idx; +} +/* 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); +}Nitpick: if the macro is meant to have a global scope, better to put it at the beginning with other macros. If the scope is only acc_ts2ktime(), then undefine them once it is out of scope. #undef ACC_TS_FACTOR #undef ACC_TS_80MHZ_SHIFT
This should really have only local scope. So I will #undef them here ...
quoted
+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_dbg(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 + * + * Section 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_DLC_RTR_FLAG; + + if (cf->can_id & CAN_EFF_FLAG) { + acc_id = cf->can_id & CAN_EFF_MASK; + acc_id |= ACC_ID_EFF_FLAG; + } else { + acc_id = cf->can_id & CAN_SFF_MASK; + } + + can_put_echo_skb(skb, netdev, core->tx_fifo_head, 0); + + core->tx_fifo_head = acc_tx_fifo_next(core, 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->acc_dlc.len & ACC_DLC_TXD_FLAG) { + 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); + + core->tx_fifo_tail = acc_tx_fifo_next(core, 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 & ACC_ID_ID_MASK; + if (msg->id & ACC_ID_EFF_FLAG) + cf->can_id |= CAN_EFF_FLAG; + + can_frame_set_cc_len(cf, msg->acc_dlc.len & ACC_DLC_DLC_MASK, + priv->can.ctrlmode); + + if (msg->acc_dlc.len & ACC_DLC_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 = acc_tx_fifo_next(core, tx_fifo_tail); + } + 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) + 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) { + stats->rx_errors++; + } else { + can_err_prot_type |= CAN_ERR_PROT_TX; + stats->tx_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) + return; + + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR | CAN_ERR_CNT; + + /* 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 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->can_id |= CAN_ERR_CNT; + cf->data[6] = txerr; + cf->data[7] = rxerr; + + skb_hwtstamps(skb)->hwtstamp = acc_ts2ktime(priv->ov, msg->ts); + + netif_rx(skb); + } + + 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 actionNitpick: consider this format * Define bit pattern meaning * ------------------------------------------------------ * 00 no action * ACC_BM_IRQ_UNMASK 01 unmask interrupt * ACC_BM_IRQ_MASK 10 mask interrupt * 11 no action (I am using spaces due to a limitation of my email client, you can use tab instead)quoted
+ * 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. + * + * Return: + * IRQ_HANDLED, if card generated an interrupt that was handled + * IRQ_NONE, if the interrupt is not ours + */ +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 = 0U; + 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; +}(...) Yours sincerely, Vincent Mailhol