From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> Add un-optimized CAN2.0 and CAN-FD transmission support. On a Rpi3 we can saturate the CAN bus at 1MHz transmitting CAN2.0 frames with DLC=0 for the number of configured tx-fifos. Afterwards we need some time to recover the state before we can fill in the fifos again. With 7 tx fifos we can: send those 7 frames in 0.33ms and then we wait for 0.26ms so that is a 56% duty cycle. With 24 tx fifos this changes to: 1.19ms for 24 frames and then we wait for 0.52ms so that is a 70% duty cycle. Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> --- drivers/net/can/spi/mcp25xxfd/Makefile | 1 + drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.c | 10 + drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.h | 3 +- .../can/spi/mcp25xxfd/mcp25xxfd_can_fifo.c | 93 ++- .../net/can/spi/mcp25xxfd/mcp25xxfd_can_int.c | 21 +- .../can/spi/mcp25xxfd/mcp25xxfd_can_priv.h | 15 +- .../net/can/spi/mcp25xxfd/mcp25xxfd_can_rx.c | 2 +- .../net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.c | 620 ++++++++++++++++++ .../net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.h | 86 +++ 9 files changed, 839 insertions(+), 12 deletions(-) create mode 100644 drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.c create mode 100644 drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.h diff --git a/drivers/net/can/spi/mcp25xxfd/Makefile b/drivers/net/can/spi/mcp25xxfd/Makefile index 5787bdd57a9d..a586b2555ff9 100644 --- a/drivers/net/can/spi/mcp25xxfd/Makefile +++ b/drivers/net/can/spi/mcp25xxfd/Makefile @@ -4,6 +4,7 @@ mcp25xxfd-objs += mcp25xxfd_can.o mcp25xxfd-objs += mcp25xxfd_can_fifo.o mcp25xxfd-objs += mcp25xxfd_can_int.o mcp25xxfd-objs += mcp25xxfd_can_rx.o +mcp25xxfd-objs += mcp25xxfd_can_tx.o mcp25xxfd-objs += mcp25xxfd_cmd.o mcp25xxfd-objs += mcp25xxfd_crc.o mcp25xxfd-objs += mcp25xxfd_ecc.o diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.c b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.c index 2ac78024c171..1417f1a22d6e 100644 --- a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.c +++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.c @@ -20,6 +20,7 @@ #include "mcp25xxfd_can_fifo.h" #include "mcp25xxfd_can_int.h" #include "mcp25xxfd_can_priv.h" +#include "mcp25xxfd_can_tx.h" #include "mcp25xxfd_can.h" #include "mcp25xxfd_cmd.h" #include "mcp25xxfd_int.h" @@ -395,6 +396,10 @@ static int mcp25xxfd_can_open(struct net_device *net) if (ret) goto out_int; + /* start the tx_queue */ + mcp25xxfd_can_tx_queue_manage(cpriv, + MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED); + return 0; out_int: @@ -425,6 +430,10 @@ static int mcp25xxfd_can_stop(struct net_device *net) struct mcp25xxfd_priv *priv = cpriv->priv; struct spi_device *spi = priv->spi; + /* stop transmit queue */ + mcp25xxfd_can_tx_queue_manage(cpriv, + MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED); + /* shutdown the can controller */ mcp25xxfd_can_shutdown(cpriv); @@ -448,6 +457,7 @@ static int mcp25xxfd_can_stop(struct net_device *net) static const struct net_device_ops mcp25xxfd_netdev_ops = { .ndo_open = mcp25xxfd_can_open, .ndo_stop = mcp25xxfd_can_stop, + .ndo_start_xmit = mcp25xxfd_can_tx_start_xmit, .ndo_change_mtu = can_change_mtu, }; diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.h b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.h index 4b18b5bb3d45..8ec20827f099 100644 --- a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.h +++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can.h @@ -22,12 +22,13 @@ int mcp25xxfd_can_targetmode(struct mcp25xxfd_can_priv *cpriv) static inline void mcp25xxfd_can_queue_frame(struct mcp25xxfd_can_priv *cpriv, - s32 fifo, u16 ts) + s32 fifo, u16 ts, bool is_rx) { int idx = cpriv->fifos.submit_queue_count; cpriv->fifos.submit_queue[idx].fifo = fifo; cpriv->fifos.submit_queue[idx].ts = ts; + cpriv->fifos.submit_queue[idx].is_rx = is_rx; cpriv->fifos.submit_queue_count++; } diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_fifo.c b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_fifo.c index 4bd776772d2d..4a1ad250bdaf 100644 --- a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_fifo.c +++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_fifo.c @@ -5,8 +5,6 @@ * Copyright 2019 Martin Sperl <kernel@xxxxxxxxxxxxxxxx> */ -/* here we define and configure the fifo layout */ - #include <linux/kernel.h> #include <linux/module.h> #include <linux/spi/spi.h> @@ -14,6 +12,7 @@ #include "mcp25xxfd_can.h" #include "mcp25xxfd_can_fifo.h" #include "mcp25xxfd_can_priv.h" +#include "mcp25xxfd_can_tx.h" #include "mcp25xxfd_cmd.h" static int mcp25xxfd_can_fifo_get_address(struct mcp25xxfd_can_priv *cpriv) @@ -55,6 +54,15 @@ static int mcp25xxfd_can_fifo_setup_config(struct mcp25xxfd_can_priv *cpriv, c > 0; i++, f++, p--, c--) { val = (c > 1) ? flags : flags_last; + /* are we in tx mode? */ + if (flags & MCP25XXFD_CAN_FIFOCON_TXEN) { + cpriv->fifos.info[f].is_rx = false; + cpriv->fifos.info[f].priority = p; + val |= (p << MCP25XXFD_CAN_FIFOCON_TXPRI_SHIFT); + } else { + cpriv->fifos.info[f].is_rx = true; + } + /* write the config to the controller in one go */ ret = mcp25xxfd_cmd_write(cpriv->priv->spi, MCP25XXFD_CAN_FIFOCON(f), val); @@ -65,6 +73,27 @@ static int mcp25xxfd_can_fifo_setup_config(struct mcp25xxfd_can_priv *cpriv, return 0; } +static int mcp25xxfd_can_fifo_setup_tx(struct mcp25xxfd_can_priv *cpriv) +{ + u32 tx_flags = MCP25XXFD_CAN_FIFOCON_FRESET | /* reset FIFO */ + MCP25XXFD_CAN_FIFOCON_TXEN | /* a tx FIFO */ + MCP25XXFD_CAN_FIFOCON_TXATIE | /* state in txatif */ + (cpriv->fifos.payload_mode << + MCP25XXFD_CAN_FIFOCON_PLSIZE_SHIFT) | /* paylod size */ + (0 << MCP25XXFD_CAN_FIFOCON_FSIZE_SHIFT); /* 1 FIFO deep */ + + /* handle oneshot/three-shot */ + if (cpriv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT) + tx_flags |= MCP25XXFD_CAN_FIFOCON_TXAT_ONE_SHOT << + MCP25XXFD_CAN_FIFOCON_TXAT_SHIFT; + else + tx_flags |= MCP25XXFD_CAN_FIFOCON_TXAT_UNLIMITED << + MCP25XXFD_CAN_FIFOCON_TXAT_SHIFT; + + return mcp25xxfd_can_fifo_setup_config(cpriv, &cpriv->fifos.tx, + tx_flags, tx_flags); +} + static int mcp25xxfd_can_fifo_setup_rx(struct mcp25xxfd_can_priv *cpriv) { u32 rx_flags = MCP25XXFD_CAN_FIFOCON_FRESET | /* reset FIFO */ @@ -106,7 +135,7 @@ static int mcp25xxfd_can_fifo_setup_rxfilter(struct mcp25xxfd_can_priv *cpriv) static int mcp25xxfd_can_fifo_compute(struct mcp25xxfd_can_priv *cpriv) { - int rx_memory_available; + int tef_memory_used, tx_memory_used, rx_memory_available; switch (cpriv->can.dev->mtu) { case CAN_MTU: @@ -114,23 +143,48 @@ static int mcp25xxfd_can_fifo_compute(struct mcp25xxfd_can_priv *cpriv) cpriv->fifos.payload_size = 8; cpriv->fifos.payload_mode = MCP25XXFD_CAN_TXQCON_PLSIZE_8; + /* 7 tx fifos */ + cpriv->fifos.tx.count = 7; + break; case CANFD_MTU: /* MTU is 64 */ cpriv->fifos.payload_size = 64; cpriv->fifos.payload_mode = MCP25XXFD_CAN_TXQCON_PLSIZE_64; + /* 7 tx fifos */ + cpriv->fifos.tx.count = 7; + break; default: return -EINVAL; } /* compute effective sizes */ + cpriv->fifos.tef.size = sizeof(struct mcp25xxfd_can_obj_tef); + cpriv->fifos.tx.size = sizeof(struct mcp25xxfd_can_obj_tx) + + cpriv->fifos.payload_size; cpriv->fifos.rx.size = sizeof(struct mcp25xxfd_can_obj_rx) + cpriv->fifos.payload_size; + /* set tef fifos to the number of tx fifos */ + cpriv->fifos.tef.count = cpriv->fifos.tx.count; + + /* compute size of the tx fifos and TEF */ + tx_memory_used = cpriv->fifos.tx.count * cpriv->fifos.tx.size; + tef_memory_used = cpriv->fifos.tef.count * cpriv->fifos.tef.size; + /* calculate evailable memory for RX_fifos */ - rx_memory_available = MCP25XXFD_SRAM_SIZE; + rx_memory_available = MCP25XXFD_SRAM_SIZE - tx_memory_used - + tef_memory_used; + + /* we need at least one RX Frame */ + if (rx_memory_available < cpriv->fifos.rx.size) { + netdev_err(cpriv->can.dev, + "Configured %i tx-fifos exceeds available memory already\n", + cpriv->fifos.tx.count); + return -EINVAL; + } /* calculate possible amount of RX fifos */ cpriv->fifos.rx.count = rx_memory_available / cpriv->fifos.rx.size; @@ -138,10 +192,11 @@ static int mcp25xxfd_can_fifo_compute(struct mcp25xxfd_can_priv *cpriv) /* now calculate effective number of rx-fifos. There are only 31 fifos * available in total, so we need to limit ourselves */ - if (cpriv->fifos.rx.count > 31) - cpriv->fifos.rx.count = 31; + if (cpriv->fifos.rx.count + cpriv->fifos.tx.count > 31) + cpriv->fifos.rx.count = 31 - cpriv->fifos.tx.count; - cpriv->fifos.rx.start = 1; + cpriv->fifos.tx.start = 1; + cpriv->fifos.rx.start = cpriv->fifos.tx.start + cpriv->fifos.tx.count; return 0; } @@ -170,6 +225,7 @@ static int mcp25xxfd_can_fifo_clear(struct mcp25xxfd_can_priv *cpriv) int ret; memset(&cpriv->fifos.info, 0, sizeof(cpriv->fifos.info)); + memset(&cpriv->fifos.tx, 0, sizeof(cpriv->fifos.tx)); memset(&cpriv->fifos.rx, 0, sizeof(cpriv->fifos.rx)); /* clear FIFO config */ @@ -196,16 +252,31 @@ int mcp25xxfd_can_fifo_setup(struct mcp25xxfd_can_priv *cpriv) if (ret) return ret; - cpriv->regs.tefcon = 0; + /* configure TEF */ + if (cpriv->fifos.tef.count) + cpriv->regs.tefcon = + MCP25XXFD_CAN_TEFCON_FRESET | + MCP25XXFD_CAN_TEFCON_TEFNEIE | + MCP25XXFD_CAN_TEFCON_TEFTSEN | + ((cpriv->fifos.tef.count - 1) << + MCP25XXFD_CAN_TEFCON_FSIZE_SHIFT); + else + cpriv->regs.tefcon = 0; ret = mcp25xxfd_cmd_write(cpriv->priv->spi, MCP25XXFD_CAN_TEFCON, cpriv->regs.tefcon); if (ret) return ret; + /* TXQueue disabled */ ret = mcp25xxfd_cmd_write(cpriv->priv->spi, MCP25XXFD_CAN_TXQCON, 0); if (ret) return ret; + /* configure FIFOS themselves */ + ret = mcp25xxfd_can_fifo_setup_tx(cpriv); + if (ret) + return ret; + ret = mcp25xxfd_can_fifo_setup_rx(cpriv); if (ret) return ret; @@ -219,10 +290,16 @@ int mcp25xxfd_can_fifo_setup(struct mcp25xxfd_can_priv *cpriv) if (ret) return ret; + /* setup tx_fifo_queue */ + ret = mcp25xxfd_can_tx_queue_alloc(cpriv); + if (ret) + return ret; + return 0; } void mcp25xxfd_can_fifo_release(struct mcp25xxfd_can_priv *cpriv) { + mcp25xxfd_can_tx_queue_free(cpriv); mcp25xxfd_can_fifo_clear(cpriv); } diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_int.c b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_int.c index 83656b2604df..b3cf3e77c299 100644 --- a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_int.c +++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_int.c @@ -23,6 +23,7 @@ #include "mcp25xxfd_can_int.h" #include "mcp25xxfd_can_priv.h" #include "mcp25xxfd_can_rx.h" +#include "mcp25xxfd_can_tx.h" #include "mcp25xxfd_cmd.h" #include "mcp25xxfd_ecc.h" @@ -80,7 +81,9 @@ static int mcp25xxfd_can_int_submit_frames(struct mcp25xxfd_can_priv *cpriv) /* now submit the fifos */ for (i = 0; i < count; i++) { fifo = queue[i].fifo; - ret = mcp25xxfd_can_rx_submit_frame(cpriv, fifo); + ret = (queue[i].is_rx) ? + mcp25xxfd_can_rx_submit_frame(cpriv, fifo) : + mcp25xxfd_can_tx_submit_frame(cpriv, fifo); if (ret) return ret; } @@ -100,6 +103,9 @@ static int mcp25xxfd_can_int_submit_frames(struct mcp25xxfd_can_priv *cpriv) } out: + /* enable tx_queue if necessary */ + mcp25xxfd_can_tx_queue_restart(cpriv); + return 0; } @@ -496,6 +502,9 @@ static int mcp25xxfd_can_int_error_handling(struct mcp25xxfd_can_priv *cpriv) cpriv->can.can_stats.bus_off++; can_bus_off(cpriv->can.dev); } + } else { + /* restart the tx queue if needed */ + mcp25xxfd_can_tx_queue_restart(cpriv); } return 0; @@ -533,6 +542,16 @@ static int mcp25xxfd_can_int_handle_status(struct mcp25xxfd_can_priv *cpriv) if (ret) return ret; + /* handle aborted TX FIFOs */ + ret = mcp25xxfd_can_tx_handle_int_txatif(cpriv); + if (ret) + return ret; + + /* handle the TEF */ + ret = mcp25xxfd_can_tx_handle_int_tefif(cpriv); + if (ret) + return ret; + /* handle error interrupt flags */ ret = mcp25xxfd_can_rx_handle_int_rxovif(cpriv); if (ret) diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_priv.h b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_priv.h index e043b262a868..99c3ef6d08e0 100644 --- a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_priv.h +++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_priv.h @@ -26,10 +26,12 @@ struct mcp25xxfd_fifo { struct mcp25xxfd_obj_ts { s32 ts; /* using signed to handle rollover correctly when sorting */ u16 fifo; + s16 is_rx; }; /* general info on each fifo */ struct mcp25xxfd_fifo_info { + u32 is_rx; u32 offset; u32 priority; }; @@ -95,10 +97,18 @@ struct mcp25xxfd_can_priv { /* infos on fifo layout */ + /* TEF */ + struct { + u32 count; + u32 size; + u32 index; + } tef; + /* info on each fifo */ struct mcp25xxfd_fifo_info info[32]; - /* extra info on rx fifo groups */ + /* extra info on rx/tx fifo groups */ + struct mcp25xxfd_fifo tx; struct mcp25xxfd_fifo rx; /* queue of can frames that need to get submitted @@ -109,6 +119,9 @@ struct mcp25xxfd_can_priv { */ struct mcp25xxfd_obj_ts submit_queue[32]; int submit_queue_count; + + /* the tx queue of spi messages */ + struct mcp25xxfd_tx_spi_message_queue *tx_queue; } fifos; /* bus state */ diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_rx.c b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_rx.c index 5e3f706e7a3f..da99145e0c94 100644 --- a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_rx.c +++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_rx.c @@ -163,7 +163,7 @@ static int mcp25xxfd_can_rx_read_frame(struct mcp25xxfd_can_priv *cpriv, memset(rx->data + len, 0, ((net->mtu == CANFD_MTU) ? 64 : 8) - len); /* add the fifo to the process queues */ - mcp25xxfd_can_queue_frame(cpriv, fifo, rx->ts); + mcp25xxfd_can_queue_frame(cpriv, fifo, rx->ts, true); /* and clear the interrupt flag for that fifo */ return mcp25xxfd_cmd_write_mask(spi, MCP25XXFD_CAN_FIFOCON(fifo), 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..5ea1e525e776 --- /dev/null +++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.c @@ -0,0 +1,620 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* CAN bus driver for Microchip 25XXFD CAN Controller with SPI Interface + * + * Copyright 2019 Martin Sperl <kernel@xxxxxxxxxxxxxxxx> + * + * Based on Microchip MCP251x CAN controller driver written by + * David Vrabel, Copyright 2006 Arcom Control Systems Ltd. + */ + +#include <linux/bitfield.h> +#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" + +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); + + 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; + + 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; + + 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.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.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); + + /* 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; + + 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: + netdev_err(cpriv->can.dev, "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_handle_int_tefif_fifo(struct mcp25xxfd_can_priv *cpriv) +{ + 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 */ + ret = mcp25xxfd_cmd_read_regs(cpriv->priv->spi, + MCP25XXFD_SRAM_ADDR(tef_offset), + &tef->id, sizeof(*tef)); + if (ret) + return ret; + + /* get the fifo from tef */ + fifo = FIELD_GET(MCP25XXFD_CAN_OBJ_FLAGS_SEQ_MASK, tef->flags); + + /* 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); + + /* now we can schedule the fifo for echo submission */ + mcp25xxfd_can_queue_frame(cpriv, fifo, tef->ts, false); + + /* increment the tef index with wraparound */ + 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); +} + +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); + if (ret) + return 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; + } + + 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; + + spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags); + + /* compute finished fifos and clear them immediately */ + finished = (cpriv->fifos.tx_queue->in_can_transfer ^ + cpriv->status.txreq) & + cpriv->fifos.tx_queue->in_can_transfer; + + spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags); + + 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); + + /* 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); + + /* 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; + + 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; + + 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_tx_spi_message_queue *q = cpriv->fifos.tx_queue; + struct mcp25xxfd_priv *priv = cpriv->priv; + struct spi_device *spi = priv->spi; + struct mcp25xxfd_tx_spi_message *smsg; + struct mcp25xxfd_can_obj_tx *tx; + unsigned long flags; + int ret; + + /* invalid skb we can ignore */ + if (can_dropped_invalid_skb(net, skb)) + return NETDEV_TX_OK; + + spin_lock_irqsave(&q->spi_lock, flags); + + /* 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; + + ret = spi_async(spi, &smsg->trigger_fifo.msg); + if (ret) + goto out_async_failed; + + spin_unlock_irqrestore(&q->spi_lock, flags); + + can_put_echo_skb(skb, net, smsg->fifo); + + return NETDEV_TX_OK; + +out_async_failed: + netdev_err(net, "spi_async submission of fifo %i failed - %i\n", + smsg->fifo, ret); + +out_busy: + mcp25xxfd_can_tx_queue_manage_nolock(cpriv, state); + spin_unlock_irqrestore(&q->spi_lock, flags); + + 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); + + 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; +} + +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; + unsigned long flags; + u32 val; + int ret; + + ret = mcp25xxfd_cmd_read(cpriv->priv->spi, + MCP25XXFD_CAN_FIFOSTA(fifo), &val); + if (ret) + return ret; + + 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); + + 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); + + cpriv->status.txif &= ~BIT(fifo); + cpriv->can.dev->stats.tx_aborted_errors++; + + return 0; +} + +int mcp25xxfd_can_tx_handle_int_txatif(struct mcp25xxfd_can_priv *cpriv) +{ + int i, f, ret; + + if (!cpriv->status.txatif) + return 0; + + /* process all the fifos with txatif 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; + + cpriv->fifos.tx_queue = kzalloc(size, GFP_KERNEL); + if (!cpriv->fifos.tx_queue) + return -ENOMEM; + + spin_lock_init(&cpriv->fifos.tx_queue->lock); + spin_lock_init(&cpriv->fifos.tx_queue->spi_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) +{ + kfree(cpriv->fifos.tx_queue); + cpriv->fifos.tx_queue = NULL; +} diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.h b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.h new file mode 100644 index 000000000000..1947b3420d58 --- /dev/null +++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd_can_tx.h @@ -0,0 +1,86 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* CAN bus driver for Microchip 25XXFD CAN Controller with SPI Interface + * + * Copyright 2019 Martin Sperl <kernel@xxxxxxxxxxxxxxxx> + */ + +#ifndef __MCP25XXFD_CAN_TX_H +#define __MCP25XXFD_CAN_TX_H + +#include <linux/spinlock.h> +#include <linux/spi/spi.h> + +#include "mcp25xxfd_can_priv.h" + +/* structure of a spi message that is prepared and can get submitted quickly */ +struct mcp25xxfd_tx_spi_message { + /* the network device this is related to */ + struct mcp25xxfd_can_priv *cpriv; + /* the fifo this fills */ + u32 fifo; + /* the xfer to fill in the fifo data */ + struct { + struct spi_message msg; + struct spi_transfer xfer; + struct { + u8 cmd[2]; + u8 header[sizeof(struct mcp25xxfd_can_obj_tx)]; + u8 data[64]; + } data; + } fill_fifo; + /* the xfer to enable transmission on the can bus */ + struct { + struct spi_message msg; + struct spi_transfer xfer; + struct { + u8 cmd[2]; + u8 data; + } data; + } trigger_fifo; +}; + +struct mcp25xxfd_tx_spi_message_queue { + /* spinlock protecting the bitmaps + * as well as state and the skb_echo_* functions + */ + spinlock_t lock; + /* bitmap of which fifo is in which stage */ + u32 idle; + u32 in_fill_fifo_transfer; + u32 in_trigger_fifo_transfer; + u32 in_can_transfer; + u32 transferred; + + /* the queue state as seen per controller */ + int state; +#define MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED 0 +#define MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED 1 +#define MCP25XXFD_CAN_TX_QUEUE_STATE_RUNABLE 2 +#define MCP25XXFD_CAN_TX_QUEUE_STATE_RESTART 3 + + /* spinlock protecting spi submission order */ + spinlock_t spi_lock; + + /* map each fifo to a mcp25xxfd_tx_spi_message */ + struct mcp25xxfd_tx_spi_message *fifo2message[32]; + + /* the individual messages */ + struct mcp25xxfd_tx_spi_message message[]; +}; + +int mcp25xxfd_can_tx_submit_frame(struct mcp25xxfd_can_priv *cpriv, int fifo); +void mcp25xxfd_can_tx_queue_restart(struct mcp25xxfd_can_priv *cpriv); + +int mcp25xxfd_can_tx_handle_int_txatif(struct mcp25xxfd_can_priv *cpriv); +int mcp25xxfd_can_tx_handle_int_tefif(struct mcp25xxfd_can_priv *cpriv); + +netdev_tx_t mcp25xxfd_can_tx_start_xmit(struct sk_buff *skb, + struct net_device *net); + +void mcp25xxfd_can_tx_queue_manage(struct mcp25xxfd_can_priv *cpriv, int state); + +int mcp25xxfd_can_tx_queue_alloc(struct mcp25xxfd_can_priv *cpriv); +void mcp25xxfd_can_tx_queue_free(struct mcp25xxfd_can_priv *cpriv); + +#endif /* __MCP25XXFD_CAN_TX_H */ -- 2.17.1