diff options
Diffstat (limited to 'drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.c')
| -rw-r--r-- | drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.c | 781 |
1 files changed, 781 insertions, 0 deletions
diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.c b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.c new file mode 100644 index 000000000000..07526a23c054 --- /dev/null +++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.c @@ -0,0 +1,781 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* CAN bus driver for Microchip 25XXFD CAN Controller with SPI Interface + * + * Copyright 2019 Martin Sperl <kernel@martin.sperl.org> + * + * Based on Microchip MCP251x CAN controller driver written by + * David Vrabel, Copyright 2006 Arcom Control Systems Ltd. + */ + +#include <linux/can/core.h> +#include <linux/can/dev.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/netdevice.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> + +#include "mcp25xxfd_can.h" +#include "mcp25xxfd_can_id.h" +#include "mcp25xxfd_can_tx.h" +#include "mcp25xxfd_cmd.h" +#include "mcp25xxfd_regs.h" + +/* mostly bit manipulations to move between stages */ +static struct mcp25xxfd_tx_spi_message * +mcp25xxfd_can_tx_queue_first_spi_message(struct mcp25xxfd_tx_spi_message_queue * + queue, u32 *bitmap) +{ + u32 first = ffs(*bitmap); + + if (!first) + return NULL; + + return queue->fifo2message[first - 1]; +} + +static void mcp25xxfd_can_tx_queue_remove_spi_message(u32 *bitmap, int fifo) +{ + *bitmap &= ~BIT(fifo); +} + +static void mcp25xxfd_can_tx_queue_add_spi_message(u32 *bitmap, int fifo) +{ + *bitmap |= BIT(fifo); +} + +static void mcp25xxfd_can_tx_queue_move_spi_message(u32 *src, u32 *dest, + int fifo) +{ + mcp25xxfd_can_tx_queue_remove_spi_message(src, fifo); + mcp25xxfd_can_tx_queue_add_spi_message(dest, fifo); +} + +static void mcp25xxfd_can_tx_spi_message_fill_fifo_complete(void *context) +{ + struct mcp25xxfd_tx_spi_message *msg = context; + struct mcp25xxfd_can_priv *cpriv = msg->cpriv; + struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue; + unsigned long flags; + + /* reset transfer length to without data (DLC = 0) */ + msg->fill_fifo.xfer.len = sizeof(msg->fill_fifo.data.cmd) + + sizeof(msg->fill_fifo.data.header); + + /* we need to hold this lock to protect us from + * concurrent access by start_xmit + */ + spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags); + + /* move to in_trigger_fifo_transfer */ + mcp25xxfd_can_tx_queue_move_spi_message(&q->in_fill_fifo_transfer, + &q->in_trigger_fifo_transfer, + msg->fifo); + + spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags); +} + +static void mcp25xxfd_can_tx_spi_message_trigger_fifo_complete(void *context) +{ + struct mcp25xxfd_tx_spi_message *msg = context; + struct mcp25xxfd_can_priv *cpriv = msg->cpriv; + struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue; + unsigned long flags; + + /* we need to hold this lock to protect us from + * concurrent access by the interrupt thread + */ + spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags); + + /* move to can_transfer */ + mcp25xxfd_can_tx_queue_move_spi_message(&q->in_trigger_fifo_transfer, + &q->in_can_transfer, + msg->fifo); + + spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags); +} + +static +void mcp25xxfd_can_tx_message_init(struct mcp25xxfd_can_priv *cpriv, + struct mcp25xxfd_tx_spi_message *msg, + int fifo) +{ + const u32 trigger = MCP25XXFD_CAN_FIFOCON_TXREQ | + MCP25XXFD_CAN_FIFOCON_UINC; + const int first_byte = mcp25xxfd_cmd_first_byte(trigger); + u32 addr; + + /* and initialize the structure */ + msg->cpriv = cpriv; + msg->fifo = fifo; + + /* init fill_fifo */ + spi_message_init(&msg->fill_fifo.msg); + msg->fill_fifo.msg.complete = + mcp25xxfd_can_tx_spi_message_fill_fifo_complete; + msg->fill_fifo.msg.context = msg; + + msg->fill_fifo.xfer.speed_hz = cpriv->priv->spi_use_speed_hz; + msg->fill_fifo.xfer.tx_buf = msg->fill_fifo.data.cmd; + msg->fill_fifo.xfer.len = sizeof(msg->fill_fifo.data.cmd) + + sizeof(msg->fill_fifo.data.header); + spi_message_add_tail(&msg->fill_fifo.xfer, &msg->fill_fifo.msg); + + addr = MCP25XXFD_SRAM_ADDR(cpriv->fifos.info[fifo].offset); + mcp25xxfd_cmd_calc(MCP25XXFD_INSTRUCTION_WRITE, addr, + msg->fill_fifo.data.cmd); + + /* init trigger_fifo */ + spi_message_init(&msg->trigger_fifo.msg); + msg->trigger_fifo.msg.complete = + mcp25xxfd_can_tx_spi_message_trigger_fifo_complete; + msg->trigger_fifo.msg.context = msg; + + msg->trigger_fifo.xfer.speed_hz = cpriv->priv->spi_use_speed_hz; + msg->trigger_fifo.xfer.tx_buf = msg->trigger_fifo.data.cmd; + msg->trigger_fifo.xfer.len = sizeof(msg->trigger_fifo.data.cmd) + + sizeof(msg->trigger_fifo.data.data); + spi_message_add_tail(&msg->trigger_fifo.xfer, &msg->trigger_fifo.msg); + + mcp25xxfd_cmd_calc(MCP25XXFD_INSTRUCTION_WRITE, + MCP25XXFD_CAN_FIFOCON(fifo) + first_byte, + msg->trigger_fifo.data.cmd); + msg->trigger_fifo.data.data = trigger >> (8 * first_byte); + + /* and add to idle tx transfers */ + mcp25xxfd_can_tx_queue_add_spi_message(&cpriv->fifos.tx_queue->idle, + fifo); +} + +static +void mcp25xxfd_can_tx_queue_manage_nolock(struct mcp25xxfd_can_priv *cpriv, + int state) +{ + struct net_device *net = cpriv->can.dev; + + /* skip early */ + if (state == cpriv->fifos.tx_queue->state) + return; + + /* start/stop netif_queue if necessary */ + switch (cpriv->fifos.tx_queue->state) { + case MCP25XXFD_CAN_TX_QUEUE_STATE_RUNABLE: + switch (state) { + case MCP25XXFD_CAN_TX_QUEUE_STATE_RESTART: + case MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED: + netif_wake_queue(net); + cpriv->fifos.tx_queue->state = + MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED; + break; + } + break; + case MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED: + switch (state) { + case MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED: + netif_wake_queue(net); + cpriv->fifos.tx_queue->state = state; + break; + } + break; + case MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED: + switch (state) { + case MCP25XXFD_CAN_TX_QUEUE_STATE_RUNABLE: + case MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED: + netif_stop_queue(net); + cpriv->fifos.tx_queue->state = state; + break; + } + break; + default: + WARN(true, "Unsupported tx_queue state: %i\n", + cpriv->fifos.tx_queue->state); + break; + } +} + +void mcp25xxfd_can_tx_queue_manage(struct mcp25xxfd_can_priv *cpriv, int state) +{ + unsigned long flags; + + spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags); + + mcp25xxfd_can_tx_queue_manage_nolock(cpriv, state); + + spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags); +} + +void mcp25xxfd_can_tx_queue_restart(struct mcp25xxfd_can_priv *cpriv) +{ + u32 state = MCP25XXFD_CAN_TX_QUEUE_STATE_RESTART; + unsigned long flags; + u32 mask; + + spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags); + + /* only move if there is nothing pending or idle */ + mask = cpriv->fifos.tx_queue->idle | + cpriv->fifos.tx_queue->in_fill_fifo_transfer | + cpriv->fifos.tx_queue->in_trigger_fifo_transfer | + cpriv->fifos.tx_queue->in_can_transfer; + if (mask) + goto out; + + /* move all items from transferred to idle */ + cpriv->fifos.tx_queue->idle |= cpriv->fifos.tx_queue->transferred; + cpriv->fifos.tx_queue->transferred = 0; + + /* and enable queue */ + mcp25xxfd_can_tx_queue_manage_nolock(cpriv, state); +out: + spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags); +} + +static +int mcp25xxfd_can_tx_tef_read(struct mcp25xxfd_can_priv *cpriv, + int start, int count) +{ + u32 tef_offset = start * cpriv->fifos.tef.size; + struct mcp25xxfd_can_obj_tef *tef = + (struct mcp25xxfd_can_obj_tef *)(cpriv->sram + tef_offset); + int last, read, ret; + + /* compute how many we can read in one go */ + last = start + count; + read = (last > cpriv->fifos.tef.count) ? + (cpriv->fifos.tef.count - start) : + count; + + /* and read it */ + ret = mcp25xxfd_cmd_read_regs(cpriv->priv->spi, + MCP25XXFD_SRAM_ADDR(tef_offset), + &tef->id, sizeof(*tef) * read); + if (ret) + return ret; + + /* and read a second part on wrap */ + if (read != count) { + /* update stats */ + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, tef_read_splits); + /* compute the addresses */ + read = count - read; + tef = (struct mcp25xxfd_can_obj_tef *)(cpriv->sram); + /* and read again */ + ret = mcp25xxfd_cmd_read_regs(cpriv->priv->spi, + MCP25XXFD_SRAM_ADDR(0), + &tef->id, + sizeof(*tef) * read); + } + + return ret; +} + +static +int mcp25xxfd_can_tx_handle_int_tefif_fifo(struct mcp25xxfd_can_priv *cpriv, + bool read_data) +{ + u32 tef_offset = cpriv->fifos.tef.index * cpriv->fifos.tef.size; + struct mcp25xxfd_can_obj_tef *tef = + (struct mcp25xxfd_can_obj_tef *)(cpriv->sram + tef_offset); + int fifo, ret; + unsigned long flags; + + /* read the next TEF entry to get the transmit timestamp and fifo */ + if (read_data) { + ret = mcp25xxfd_can_tx_tef_read(cpriv, + cpriv->fifos.tef.index, 1); + if (ret) + return ret; + } + + /* get the fifo from tef */ + fifo = (tef->flags & MCP25XXFD_CAN_OBJ_FLAGS_SEQ_MASK) >> + MCP25XXFD_CAN_OBJ_FLAGS_SEQ_SHIFT; + + /* check that the fifo is valid */ + spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags); + if ((cpriv->fifos.tx_queue->in_can_transfer & BIT(fifo)) == 0) + netdev_err(cpriv->can.dev, + "tefif: fifo %i not pending - tef data: id: %08x flags: %08x, ts: %08x - this may be a problem with spi signal quality- try reducing spi-clock speed if this can get reproduced", + fifo, tef->id, tef->flags, tef->ts); + spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags); + + /* update stats */ + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, tef_reads); + + /* now we can schedule the fifo for echo submission */ + mcp25xxfd_can_queue_frame(cpriv, fifo, tef->ts, false); + + /* increment the tef index with wraparround */ + cpriv->fifos.tef.index++; + if (cpriv->fifos.tef.index >= cpriv->fifos.tef.count) + cpriv->fifos.tef.index = 0; + + /* finally just increment the TEF pointer */ + return mcp25xxfd_cmd_write_mask(cpriv->priv->spi, MCP25XXFD_CAN_TEFCON, + MCP25XXFD_CAN_TEFCON_UINC, + MCP25XXFD_CAN_TEFCON_UINC); +} + +/* reading TEF entries can be made even more efficient by reading + * multiple TEF entries in one go. + * Under the assumption that we have count(TEF) >= count(TX_FIFO) + * we can even release TEFs early (before we read them) + * (and potentially restarting the transmit-queue early aswell) + */ + +static int +mcp25xxfd_can_tx_handle_int_tefif_conservative(struct mcp25xxfd_can_priv *cpriv) +{ + u32 tefsta; + int ret; + + /* read the TEF status */ + ret = mcp25xxfd_cmd_read_mask(cpriv->priv->spi, MCP25XXFD_CAN_TEFSTA, + &tefsta, MCP25XXFD_CAN_TEFSTA_TEFNEIF); + if (ret) + return ret; + + /* read the tef in an inefficient loop */ + while (tefsta & MCP25XXFD_CAN_TEFSTA_TEFNEIF) { + /* read one tef */ + ret = mcp25xxfd_can_tx_handle_int_tefif_fifo(cpriv, true); + if (ret) + return ret; + + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, tef_conservative_reads); + + /* read the TEF status */ + ret = mcp25xxfd_cmd_read_mask(cpriv->priv->spi, + MCP25XXFD_CAN_TEFSTA, &tefsta, + MCP25XXFD_CAN_TEFSTA_TEFNEIF); + if (ret) + return ret; + } + + return 0; +} + +static int +mcp25xxfd_can_tx_handle_int_tefif_optimized(struct mcp25xxfd_can_priv *cpriv, + u32 finished) +{ + int i, fifo, count, ret; + + /* count the number of fifos that have terminated */ + for (i = 0, fifo = cpriv->fifos.tx.start, count = 0; + i < cpriv->fifos.tx.count; i++, fifo++) + if (finished & BIT(fifo)) + count++; + + /* read them in one go if possible + * we also assume that we have count(TEF) >= count(TX-FIFOS) + * this may require 2 reads when we wrap arround + * (that is unless count(TEF) == count(TX-FIFOS)) + */ + ret = mcp25xxfd_can_tx_tef_read(cpriv, cpriv->fifos.tef.index, count); + if (ret) + return ret; + + /* update stats */ + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, tef_optimized_reads); + i = min_t(int, MCP25XXFD_CAN_TEF_READ_BINS - 1, count - 1); + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, tef_optimized_read_sizes[i]); + + /* now iterate those */ + for (i = 0, fifo = cpriv->fifos.tx.start; i < cpriv->fifos.tx.count; + i++, fifo++) { + if (finished & BIT(fifo)) { + ret = mcp25xxfd_can_tx_handle_int_tefif_fifo(cpriv, + false); + if (ret) + return ret; + } + } + + return 0; +} + +int mcp25xxfd_can_tx_handle_int_tefif(struct mcp25xxfd_can_priv *cpriv) +{ + unsigned long flags; + u32 finished; + + if (!(cpriv->status.intf & MCP25XXFD_CAN_INT_TEFIF)) + return 0; + + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, int_tef_count); + + /* compute finished fifos and clear them immediately + * + * bit in txreq == 0 means successfully sent + */ + spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags); + finished = ~cpriv->status.txreq & cpriv->fifos.tx_queue->in_can_transfer; + spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags); + + /* run in optimized mode if possible */ + if (finished) + return mcp25xxfd_can_tx_handle_int_tefif_optimized(cpriv, + finished); + /* otherwise play it safe */ + netdev_warn(cpriv->can.dev, + "Something is wrong - we got a TEF interrupt but we were not able to detect a finished fifo\n"); + return mcp25xxfd_can_tx_handle_int_tefif_conservative(cpriv); +} + +static +void mcp25xxfd_can_tx_fill_fifo_common(struct mcp25xxfd_can_priv *cpriv, + struct mcp25xxfd_tx_spi_message *smsg, + struct mcp25xxfd_can_obj_tx *tx, + int dlc, u8 *data) +{ + int len = can_dlc2len(dlc); + + /* update statistics */ + MCP25XXFD_DEBUGFS_INCR(cpriv->fifos.tx.dlc_usage[dlc]); + MCP25XXFD_DEBUGFS_INCR(cpriv->fifos.info[smsg->fifo].use_count); + + /* add fifo number as seq */ + tx->flags |= smsg->fifo << MCP25XXFD_CAN_OBJ_FLAGS_SEQ_SHIFT; + + /* copy data to tx->data for future reference */ + memcpy(tx->data, data, len); + + /* transform header to controller format */ + mcp25xxfd_cmd_convert_from_cpu(&tx->id, sizeof(*tx) / sizeof(u32)); + + /* copy header + data to final location - we are not aligned */ + memcpy(smsg->fill_fifo.data.header, &tx->id, sizeof(*tx) + len); + + /* transfers to sram should be a multiple of 4 and be zero padded */ + for (; len & 3; len++) + *(smsg->fill_fifo.data.header + sizeof(*tx) + len) = 0; + + /* convert it back to CPU format */ + mcp25xxfd_cmd_convert_to_cpu(&tx->id, sizeof(*tx) / sizeof(u32)); + + /* set up size of transfer */ + smsg->fill_fifo.xfer.len = sizeof(smsg->fill_fifo.data.cmd) + + sizeof(smsg->fill_fifo.data.header) + len; +} + +static +void mcp25xxfd_can_tx_fill_fifo_fd(struct mcp25xxfd_can_priv *cpriv, + struct canfd_frame *frame, + struct mcp25xxfd_tx_spi_message *smsg, + struct mcp25xxfd_can_obj_tx *tx) +{ + int dlc = can_len2dlc(frame->len); + + /* update some statistics */ + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, tx_fd_count); + + /* compute can id */ + mcp25xxfd_can_id_to_mcp25xxfd(frame->can_id, &tx->id, &tx->flags); + + /* setup flags */ + tx->flags |= dlc << MCP25XXFD_CAN_OBJ_FLAGS_DLC_SHIFT; + tx->flags |= (frame->can_id & CAN_EFF_FLAG) ? + MCP25XXFD_CAN_OBJ_FLAGS_IDE : 0; + tx->flags |= (frame->can_id & CAN_RTR_FLAG) ? + MCP25XXFD_CAN_OBJ_FLAGS_RTR : 0; + if (frame->flags & CANFD_BRS) { + tx->flags |= MCP25XXFD_CAN_OBJ_FLAGS_BRS; + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, tx_brs_count); + } + tx->flags |= (frame->flags & CANFD_ESI) ? + MCP25XXFD_CAN_OBJ_FLAGS_ESI : 0; + tx->flags |= MCP25XXFD_CAN_OBJ_FLAGS_FDF; + + /* and do common processing */ + mcp25xxfd_can_tx_fill_fifo_common(cpriv, smsg, tx, dlc, frame->data); +} + +static +void mcp25xxfd_can_tx_fill_fifo(struct mcp25xxfd_can_priv *cpriv, + struct can_frame *frame, + struct mcp25xxfd_tx_spi_message *smsg, + struct mcp25xxfd_can_obj_tx *tx) +{ + /* set frame to valid dlc */ + if (frame->can_dlc > 8) + frame->can_dlc = 8; + + /* compute can id */ + mcp25xxfd_can_id_to_mcp25xxfd(frame->can_id, &tx->id, &tx->flags); + + /* setup flags */ + tx->flags |= frame->can_dlc << MCP25XXFD_CAN_OBJ_FLAGS_DLC_SHIFT; + tx->flags |= (frame->can_id & CAN_EFF_FLAG) ? + MCP25XXFD_CAN_OBJ_FLAGS_IDE : 0; + tx->flags |= (frame->can_id & CAN_RTR_FLAG) ? + MCP25XXFD_CAN_OBJ_FLAGS_RTR : 0; + + /* and do common processing */ + mcp25xxfd_can_tx_fill_fifo_common(cpriv, smsg, tx, frame->can_dlc, + frame->data); +} + +static struct mcp25xxfd_tx_spi_message * +mcp25xxfd_can_tx_queue_get_next_fifo(struct mcp25xxfd_can_priv *cpriv) +{ + u32 state = MCP25XXFD_CAN_TX_QUEUE_STATE_RUNABLE; + struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue; + struct mcp25xxfd_tx_spi_message *smsg; + unsigned long flags; + + /* we need to hold this lock to protect us against + * concurrent modifications of cpriv->fifos.tx_queue->idle + * in the interrupt thread + */ + spin_lock_irqsave(&q->lock, flags); + + /* get the first entry from idle */ + smsg = mcp25xxfd_can_tx_queue_first_spi_message(q, &q->idle); + if (!smsg) + goto out_busy; + + /* and move the fifo to next stage */ + mcp25xxfd_can_tx_queue_move_spi_message(&q->idle, + &q->in_fill_fifo_transfer, + smsg->fifo); + + /* if queue is empty then stop the network queue immediately */ + if (!q->idle) + mcp25xxfd_can_tx_queue_manage_nolock(cpriv, state); +out_busy: + spin_unlock_irqrestore(&q->lock, flags); + + return smsg; +} + +/* submit the can message to the can-bus */ +netdev_tx_t mcp25xxfd_can_tx_start_xmit(struct sk_buff *skb, + struct net_device *net) +{ + u32 state = MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED; + struct mcp25xxfd_can_priv *cpriv = netdev_priv(net); + struct mcp25xxfd_priv *priv = cpriv->priv; + struct spi_device *spi = priv->spi; + struct mcp25xxfd_tx_spi_message *smsg; + struct mcp25xxfd_can_obj_tx *tx; + int ret; + + /* invalid skb we can ignore */ + if (can_dropped_invalid_skb(net, skb)) + return NETDEV_TX_OK; + + /* get the fifo message structure to process now */ + smsg = mcp25xxfd_can_tx_queue_get_next_fifo(cpriv); + if (!smsg) + goto out_busy; + + /* compute the fifo in sram */ + tx = (struct mcp25xxfd_can_obj_tx *) + (cpriv->sram + cpriv->fifos.info[smsg->fifo].offset); + + /* fill in message from skb->data depending on can2.0 or canfd */ + if (can_is_canfd_skb(skb)) + mcp25xxfd_can_tx_fill_fifo_fd(cpriv, + (struct canfd_frame *)skb->data, + smsg, tx); + else + mcp25xxfd_can_tx_fill_fifo(cpriv, + (struct can_frame *)skb->data, + smsg, tx); + + /* submit the two messages asyncronously + * the reason why we separate transfers into two spi_messages is: + * * because the spi framework (currently) does add a 10us delay + * between 2 spi_transfers in a single spi_message when + * change_cs is set - 2 consecutive spi messages show a shorter + * cs disable phase increasing bus utilization + * (code reduction with a fix in spi core would be aprox.50 lines) + * * this allows the interrupt handler to start spi messages earlier + * so reducing latencies a bit and to allow for better concurrency + * * this separation - in the future - may get used to fill fifos + * early and reduce the delay on "rollover" + */ + ret = spi_async(spi, &smsg->fill_fifo.msg); + if (ret) + goto out_async_failed; + + /* keep it for reference until the message really got transmitted */ + can_put_echo_skb(skb, net, smsg->fifo); + + ret = spi_async(spi, &smsg->trigger_fifo.msg); + if (ret) + goto out_async_failed; + + return NETDEV_TX_OK; +out_async_failed: + netdev_err(net, "spi_async submission of fifo %i failed - %i\n", + smsg->fifo, ret); + +out_busy: + /* stop the queue */ + mcp25xxfd_can_tx_queue_manage_nolock(cpriv, state); + + return NETDEV_TX_BUSY; +} + +/* submit the fifo back to the network stack */ +int mcp25xxfd_can_tx_submit_frame(struct mcp25xxfd_can_priv *cpriv, int fifo) +{ + struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue; + struct mcp25xxfd_can_obj_tx *tx = (struct mcp25xxfd_can_obj_tx *) + (cpriv->sram + cpriv->fifos.info[fifo].offset); + int dlc = (tx->flags & MCP25XXFD_CAN_OBJ_FLAGS_DLC_MASK) >> + MCP25XXFD_CAN_OBJ_FLAGS_DLC_SHIFT; + unsigned long flags; + + /* update counters */ + cpriv->can.dev->stats.tx_packets++; + cpriv->can.dev->stats.tx_bytes += can_dlc2len(dlc); + MCP25XXFD_DEBUGFS_INCR(cpriv->fifos.tx.dlc_usage[dlc]); + if (tx->flags & MCP25XXFD_CAN_OBJ_FLAGS_FDF) + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, tx_fd_count); + if (tx->flags & MCP25XXFD_CAN_OBJ_FLAGS_BRS) + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, tx_brs_count); + + spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags); + + /* release the echo buffer */ + can_get_echo_skb(cpriv->can.dev, fifo); + + /* move from in_can_transfer to transferred */ + mcp25xxfd_can_tx_queue_move_spi_message(&q->in_can_transfer, + &q->transferred, fifo); + + spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags); + + return 0; +} + +/* interrupt handler */ +static +int mcp25xxfd_can_tx_handle_int_txatif_fifo(struct mcp25xxfd_can_priv *cpriv, + int fifo) +{ + struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue; + u32 val; + unsigned long flags; + int ret; + + /* read fifo status */ + ret = mcp25xxfd_cmd_read(cpriv->priv->spi, + MCP25XXFD_CAN_FIFOSTA(fifo), &val); + if (ret) + return ret; + + /* clear the relevant interrupt flags */ + ret = mcp25xxfd_cmd_write_mask(cpriv->priv->spi, + MCP25XXFD_CAN_FIFOSTA(fifo), 0, + MCP25XXFD_CAN_FIFOSTA_TXABT | + MCP25XXFD_CAN_FIFOSTA_TXLARB | + MCP25XXFD_CAN_FIFOSTA_TXERR | + MCP25XXFD_CAN_FIFOSTA_TXATIF); + if (ret) + return ret; + + spin_lock_irqsave(&q->lock, flags); + /* for specific cases we probably could trigger a retransmit + * instead of an abort. + */ + + /* and we release it from the echo_skb buffer + * NOTE: this is one place where packet delivery will not + * be ordered, as we do not have any timing information + * when this occurred + */ + can_get_echo_skb(cpriv->can.dev, fifo); + + mcp25xxfd_can_tx_queue_move_spi_message(&q->in_can_transfer, + &q->transferred, fifo); + + spin_unlock_irqrestore(&q->lock, flags); + + /* but we need to run a bit of cleanup */ + cpriv->status.txif &= ~BIT(fifo); + cpriv->can.dev->stats.tx_aborted_errors++; + + /* handle all the known cases accordingly - ignoring FIFO full */ + val &= MCP25XXFD_CAN_FIFOSTA_TXABT | + MCP25XXFD_CAN_FIFOSTA_TXLARB | + MCP25XXFD_CAN_FIFOSTA_TXERR; + switch (val) { + case MCP25XXFD_CAN_FIFOSTA_TXERR: + /* this indicates a possible bus error */ + break; + default: + dev_warn_ratelimited(&cpriv->priv->spi->dev, + "Unknown TX-Fifo abort condition: %08x - stopping tx-queue\n", + val); + break; + } + + return 0; +} + +int mcp25xxfd_can_tx_handle_int_txatif(struct mcp25xxfd_can_priv *cpriv) +{ + int i, f, ret; + + /* if txatif is unset, then there are no + * can frames that have been transmitted + * and need to get reingested into the network stack + */ + if (!cpriv->status.txatif) + return 0; + MCP25XXFD_DEBUGFS_STATS_INCR(cpriv, int_txat_count); + + /* process all the fifos with that flag set */ + for (i = 0, f = cpriv->fifos.tx.start; i < cpriv->fifos.tx.count; + i++, f++) { + if (cpriv->status.txatif & BIT(f)) { + ret = mcp25xxfd_can_tx_handle_int_txatif_fifo(cpriv, f); + if (ret) + return ret; + } + } + + return 0; +} + +int mcp25xxfd_can_tx_queue_alloc(struct mcp25xxfd_can_priv *cpriv) +{ + struct mcp25xxfd_tx_spi_message *msg; + size_t size = sizeof(struct mcp25xxfd_tx_spi_message_queue) + + cpriv->fifos.tx.count * sizeof(*msg); + int i, f; + + /* allocate the fifos as an array */ + cpriv->fifos.tx_queue = kzalloc(size, GFP_KERNEL); + if (!cpriv->fifos.tx_queue) + return -ENOMEM; + + /* initialize the tx_queue structure */ + spin_lock_init(&cpriv->fifos.tx_queue->lock); + + /* initialize the individual spi_message structures */ + for (i = 0, f = cpriv->fifos.tx.start; i < cpriv->fifos.tx.count; + i++, f++) { + msg = &cpriv->fifos.tx_queue->message[i]; + cpriv->fifos.tx_queue->fifo2message[f] = msg; + mcp25xxfd_can_tx_message_init(cpriv, msg, f); + } + + return 0; +} + +void mcp25xxfd_can_tx_queue_free(struct mcp25xxfd_can_priv *cpriv) +{ + /* eventually we may need to wait here + * for all transfers to have finished + */ + + kfree(cpriv->fifos.tx_queue); + cpriv->fifos.tx_queue = NULL; +} |