linux/linux-5.18.11/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c

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2024-03-22 18:12:32 +00:00
// SPDX-License-Identifier: GPL-2.0
//
// mcp251xfd - Microchip MCP251xFD Family CAN controller driver
//
// Copyright (c) 2019, 2020, 2021 Pengutronix,
// Marc Kleine-Budde <kernel@pengutronix.de>
//
// Based on:
//
// CAN bus driver for Microchip 25XXFD CAN Controller with SPI Interface
//
// Copyright (c) 2019 Martin Sperl <kernel@martin.sperl.org>
//
#include <asm/unaligned.h>
#include "mcp251xfd.h"
#include "mcp251xfd-ram.h"
static inline u8
mcp251xfd_cmd_prepare_write_reg(const struct mcp251xfd_priv *priv,
union mcp251xfd_write_reg_buf *write_reg_buf,
const u16 reg, const u32 mask, const u32 val)
{
u8 first_byte, last_byte, len;
u8 *data;
__le32 val_le32;
first_byte = mcp251xfd_first_byte_set(mask);
last_byte = mcp251xfd_last_byte_set(mask);
len = last_byte - first_byte + 1;
data = mcp251xfd_spi_cmd_write(priv, write_reg_buf, reg + first_byte);
val_le32 = cpu_to_le32(val >> BITS_PER_BYTE * first_byte);
memcpy(data, &val_le32, len);
if (priv->devtype_data.quirks & MCP251XFD_QUIRK_CRC_REG) {
u16 crc;
mcp251xfd_spi_cmd_crc_set_len_in_reg(&write_reg_buf->crc.cmd,
len);
/* CRC */
len += sizeof(write_reg_buf->crc.cmd);
crc = mcp251xfd_crc16_compute(&write_reg_buf->crc, len);
put_unaligned_be16(crc, (void *)write_reg_buf + len);
/* Total length */
len += sizeof(write_reg_buf->crc.crc);
} else {
len += sizeof(write_reg_buf->nocrc.cmd);
}
return len;
}
static void
mcp251xfd_ring_init_tef(struct mcp251xfd_priv *priv, u16 *base)
{
struct mcp251xfd_tef_ring *tef_ring;
struct spi_transfer *xfer;
u32 val;
u16 addr;
u8 len;
int i;
/* TEF */
tef_ring = priv->tef;
tef_ring->head = 0;
tef_ring->tail = 0;
/* TEF- and TX-FIFO have same number of objects */
*base = mcp251xfd_get_tef_obj_addr(priv->tx->obj_num);
/* FIFO IRQ enable */
addr = MCP251XFD_REG_TEFCON;
val = MCP251XFD_REG_TEFCON_TEFOVIE | MCP251XFD_REG_TEFCON_TEFNEIE;
len = mcp251xfd_cmd_prepare_write_reg(priv, &tef_ring->irq_enable_buf,
addr, val, val);
tef_ring->irq_enable_xfer.tx_buf = &tef_ring->irq_enable_buf;
tef_ring->irq_enable_xfer.len = len;
spi_message_init_with_transfers(&tef_ring->irq_enable_msg,
&tef_ring->irq_enable_xfer, 1);
/* FIFO increment TEF tail pointer */
addr = MCP251XFD_REG_TEFCON;
val = MCP251XFD_REG_TEFCON_UINC;
len = mcp251xfd_cmd_prepare_write_reg(priv, &tef_ring->uinc_buf,
addr, val, val);
for (i = 0; i < ARRAY_SIZE(tef_ring->uinc_xfer); i++) {
xfer = &tef_ring->uinc_xfer[i];
xfer->tx_buf = &tef_ring->uinc_buf;
xfer->len = len;
xfer->cs_change = 1;
xfer->cs_change_delay.value = 0;
xfer->cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
}
/* "cs_change == 1" on the last transfer results in an active
* chip select after the complete SPI message. This causes the
* controller to interpret the next register access as
* data. Set "cs_change" of the last transfer to "0" to
* properly deactivate the chip select at the end of the
* message.
*/
xfer->cs_change = 0;
if (priv->tx_coalesce_usecs_irq || priv->tx_obj_num_coalesce_irq) {
val = MCP251XFD_REG_TEFCON_UINC |
MCP251XFD_REG_TEFCON_TEFOVIE |
MCP251XFD_REG_TEFCON_TEFHIE;
len = mcp251xfd_cmd_prepare_write_reg(priv,
&tef_ring->uinc_irq_disable_buf,
addr, val, val);
xfer->tx_buf = &tef_ring->uinc_irq_disable_buf;
xfer->len = len;
}
}
static void
mcp251xfd_tx_ring_init_tx_obj(const struct mcp251xfd_priv *priv,
const struct mcp251xfd_tx_ring *ring,
struct mcp251xfd_tx_obj *tx_obj,
const u8 rts_buf_len,
const u8 n)
{
struct spi_transfer *xfer;
u16 addr;
/* FIFO load */
addr = mcp251xfd_get_tx_obj_addr(ring, n);
if (priv->devtype_data.quirks & MCP251XFD_QUIRK_CRC_TX)
mcp251xfd_spi_cmd_write_crc_set_addr(&tx_obj->buf.crc.cmd,
addr);
else
mcp251xfd_spi_cmd_write_nocrc(&tx_obj->buf.nocrc.cmd,
addr);
xfer = &tx_obj->xfer[0];
xfer->tx_buf = &tx_obj->buf;
xfer->len = 0; /* actual len is assigned on the fly */
xfer->cs_change = 1;
xfer->cs_change_delay.value = 0;
xfer->cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
/* FIFO request to send */
xfer = &tx_obj->xfer[1];
xfer->tx_buf = &ring->rts_buf;
xfer->len = rts_buf_len;
/* SPI message */
spi_message_init_with_transfers(&tx_obj->msg, tx_obj->xfer,
ARRAY_SIZE(tx_obj->xfer));
}
static void
mcp251xfd_ring_init_tx(struct mcp251xfd_priv *priv, u16 *base, u8 *fifo_nr)
{
struct mcp251xfd_tx_ring *tx_ring;
struct mcp251xfd_tx_obj *tx_obj;
u32 val;
u16 addr;
u8 len;
int i;
tx_ring = priv->tx;
tx_ring->head = 0;
tx_ring->tail = 0;
tx_ring->base = *base;
tx_ring->nr = 0;
tx_ring->fifo_nr = *fifo_nr;
*base = mcp251xfd_get_tx_obj_addr(tx_ring, tx_ring->obj_num);
*fifo_nr += 1;
/* FIFO request to send */
addr = MCP251XFD_REG_FIFOCON(tx_ring->fifo_nr);
val = MCP251XFD_REG_FIFOCON_TXREQ | MCP251XFD_REG_FIFOCON_UINC;
len = mcp251xfd_cmd_prepare_write_reg(priv, &tx_ring->rts_buf,
addr, val, val);
mcp251xfd_for_each_tx_obj(tx_ring, tx_obj, i)
mcp251xfd_tx_ring_init_tx_obj(priv, tx_ring, tx_obj, len, i);
}
static void
mcp251xfd_ring_init_rx(struct mcp251xfd_priv *priv, u16 *base, u8 *fifo_nr)
{
struct mcp251xfd_rx_ring *rx_ring;
struct spi_transfer *xfer;
u32 val;
u16 addr;
u8 len;
int i, j;
mcp251xfd_for_each_rx_ring(priv, rx_ring, i) {
rx_ring->head = 0;
rx_ring->tail = 0;
rx_ring->base = *base;
rx_ring->nr = i;
rx_ring->fifo_nr = *fifo_nr;
*base = mcp251xfd_get_rx_obj_addr(rx_ring, rx_ring->obj_num);
*fifo_nr += 1;
/* FIFO IRQ enable */
addr = MCP251XFD_REG_FIFOCON(rx_ring->fifo_nr);
val = MCP251XFD_REG_FIFOCON_RXOVIE |
MCP251XFD_REG_FIFOCON_TFNRFNIE;
len = mcp251xfd_cmd_prepare_write_reg(priv, &rx_ring->irq_enable_buf,
addr, val, val);
rx_ring->irq_enable_xfer.tx_buf = &rx_ring->irq_enable_buf;
rx_ring->irq_enable_xfer.len = len;
spi_message_init_with_transfers(&rx_ring->irq_enable_msg,
&rx_ring->irq_enable_xfer, 1);
/* FIFO increment RX tail pointer */
val = MCP251XFD_REG_FIFOCON_UINC;
len = mcp251xfd_cmd_prepare_write_reg(priv, &rx_ring->uinc_buf,
addr, val, val);
for (j = 0; j < ARRAY_SIZE(rx_ring->uinc_xfer); j++) {
xfer = &rx_ring->uinc_xfer[j];
xfer->tx_buf = &rx_ring->uinc_buf;
xfer->len = len;
xfer->cs_change = 1;
xfer->cs_change_delay.value = 0;
xfer->cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
}
/* "cs_change == 1" on the last transfer results in an
* active chip select after the complete SPI
* message. This causes the controller to interpret
* the next register access as data. Set "cs_change"
* of the last transfer to "0" to properly deactivate
* the chip select at the end of the message.
*/
xfer->cs_change = 0;
/* Use 1st RX-FIFO for IRQ coalescing. If enabled
* (rx_coalesce_usecs_irq or rx_max_coalesce_frames_irq
* is activated), use the last transfer to disable:
*
* - TFNRFNIE (Receive FIFO Not Empty Interrupt)
*
* and enable:
*
* - TFHRFHIE (Receive FIFO Half Full Interrupt)
* - or -
* - TFERFFIE (Receive FIFO Full Interrupt)
*
* depending on rx_max_coalesce_frames_irq.
*
* The RXOVIE (Overflow Interrupt) is always enabled.
*/
if (rx_ring->nr == 0 && (priv->rx_coalesce_usecs_irq ||
priv->rx_obj_num_coalesce_irq)) {
val = MCP251XFD_REG_FIFOCON_UINC |
MCP251XFD_REG_FIFOCON_RXOVIE;
if (priv->rx_obj_num_coalesce_irq == rx_ring->obj_num)
val |= MCP251XFD_REG_FIFOCON_TFERFFIE;
else if (priv->rx_obj_num_coalesce_irq)
val |= MCP251XFD_REG_FIFOCON_TFHRFHIE;
len = mcp251xfd_cmd_prepare_write_reg(priv,
&rx_ring->uinc_irq_disable_buf,
addr, val, val);
xfer->tx_buf = &rx_ring->uinc_irq_disable_buf;
xfer->len = len;
}
}
}
int mcp251xfd_ring_init(struct mcp251xfd_priv *priv)
{
const struct mcp251xfd_rx_ring *rx_ring;
u16 base = 0, ram_used;
u8 fifo_nr = 1;
int i;
netdev_reset_queue(priv->ndev);
mcp251xfd_ring_init_tef(priv, &base);
mcp251xfd_ring_init_rx(priv, &base, &fifo_nr);
mcp251xfd_ring_init_tx(priv, &base, &fifo_nr);
/* mcp251xfd_handle_rxif() will iterate over all RX rings.
* Rings with their corresponding bit set in
* priv->regs_status.rxif are read out.
*
* If the chip is configured for only 1 RX-FIFO, and if there
* is an RX interrupt pending (RXIF in INT register is set),
* it must be the 1st RX-FIFO.
*
* We mark the RXIF of the 1st FIFO as pending here, so that
* we can skip the read of the RXIF register in
* mcp251xfd_read_regs_status() for the 1 RX-FIFO only case.
*
* If we use more than 1 RX-FIFO, this value gets overwritten
* in mcp251xfd_read_regs_status(), so set it unconditionally
* here.
*/
priv->regs_status.rxif = BIT(priv->rx[0]->fifo_nr);
if (priv->tx_obj_num_coalesce_irq) {
netdev_dbg(priv->ndev,
"FIFO setup: TEF: 0x%03x: %2d*%zu bytes = %4zu bytes (coalesce)\n",
mcp251xfd_get_tef_obj_addr(0),
priv->tx_obj_num_coalesce_irq,
sizeof(struct mcp251xfd_hw_tef_obj),
priv->tx_obj_num_coalesce_irq *
sizeof(struct mcp251xfd_hw_tef_obj));
netdev_dbg(priv->ndev,
" 0x%03x: %2d*%zu bytes = %4zu bytes\n",
mcp251xfd_get_tef_obj_addr(priv->tx_obj_num_coalesce_irq),
priv->tx->obj_num - priv->tx_obj_num_coalesce_irq,
sizeof(struct mcp251xfd_hw_tef_obj),
(priv->tx->obj_num - priv->tx_obj_num_coalesce_irq) *
sizeof(struct mcp251xfd_hw_tef_obj));
} else {
netdev_dbg(priv->ndev,
"FIFO setup: TEF: 0x%03x: %2d*%zu bytes = %4zu bytes\n",
mcp251xfd_get_tef_obj_addr(0),
priv->tx->obj_num, sizeof(struct mcp251xfd_hw_tef_obj),
priv->tx->obj_num * sizeof(struct mcp251xfd_hw_tef_obj));
}
mcp251xfd_for_each_rx_ring(priv, rx_ring, i) {
if (rx_ring->nr == 0 && priv->rx_obj_num_coalesce_irq) {
netdev_dbg(priv->ndev,
"FIFO setup: RX-%u: FIFO %u/0x%03x: %2u*%u bytes = %4u bytes (coalesce)\n",
rx_ring->nr, rx_ring->fifo_nr,
mcp251xfd_get_rx_obj_addr(rx_ring, 0),
priv->rx_obj_num_coalesce_irq, rx_ring->obj_size,
priv->rx_obj_num_coalesce_irq * rx_ring->obj_size);
if (priv->rx_obj_num_coalesce_irq == MCP251XFD_FIFO_DEPTH)
continue;
netdev_dbg(priv->ndev,
" 0x%03x: %2u*%u bytes = %4u bytes\n",
mcp251xfd_get_rx_obj_addr(rx_ring,
priv->rx_obj_num_coalesce_irq),
rx_ring->obj_num - priv->rx_obj_num_coalesce_irq,
rx_ring->obj_size,
(rx_ring->obj_num - priv->rx_obj_num_coalesce_irq) *
rx_ring->obj_size);
} else {
netdev_dbg(priv->ndev,
"FIFO setup: RX-%u: FIFO %u/0x%03x: %2u*%u bytes = %4u bytes\n",
rx_ring->nr, rx_ring->fifo_nr,
mcp251xfd_get_rx_obj_addr(rx_ring, 0),
rx_ring->obj_num, rx_ring->obj_size,
rx_ring->obj_num * rx_ring->obj_size);
}
}
netdev_dbg(priv->ndev,
"FIFO setup: TX: FIFO %u/0x%03x: %2u*%u bytes = %4u bytes\n",
priv->tx->fifo_nr,
mcp251xfd_get_tx_obj_addr(priv->tx, 0),
priv->tx->obj_num, priv->tx->obj_size,
priv->tx->obj_num * priv->tx->obj_size);
netdev_dbg(priv->ndev,
"FIFO setup: free: %4d bytes\n",
MCP251XFD_RAM_SIZE - (base - MCP251XFD_RAM_START));
ram_used = base - MCP251XFD_RAM_START;
if (ram_used > MCP251XFD_RAM_SIZE) {
netdev_err(priv->ndev,
"Error during ring configuration, using more RAM (%u bytes) than available (%u bytes).\n",
ram_used, MCP251XFD_RAM_SIZE);
return -ENOMEM;
}
return 0;
}
void mcp251xfd_ring_free(struct mcp251xfd_priv *priv)
{
int i;
for (i = ARRAY_SIZE(priv->rx) - 1; i >= 0; i--) {
kfree(priv->rx[i]);
priv->rx[i] = NULL;
}
}
static enum hrtimer_restart mcp251xfd_rx_irq_timer(struct hrtimer *t)
{
struct mcp251xfd_priv *priv = container_of(t, struct mcp251xfd_priv,
rx_irq_timer);
struct mcp251xfd_rx_ring *ring = priv->rx[0];
if (test_bit(MCP251XFD_FLAGS_DOWN, priv->flags))
return HRTIMER_NORESTART;
spi_async(priv->spi, &ring->irq_enable_msg);
return HRTIMER_NORESTART;
}
static enum hrtimer_restart mcp251xfd_tx_irq_timer(struct hrtimer *t)
{
struct mcp251xfd_priv *priv = container_of(t, struct mcp251xfd_priv,
tx_irq_timer);
struct mcp251xfd_tef_ring *ring = priv->tef;
if (test_bit(MCP251XFD_FLAGS_DOWN, priv->flags))
return HRTIMER_NORESTART;
spi_async(priv->spi, &ring->irq_enable_msg);
return HRTIMER_NORESTART;
}
const struct can_ram_config mcp251xfd_ram_config = {
.rx = {
.size[CAN_RAM_MODE_CAN] = sizeof(struct mcp251xfd_hw_rx_obj_can),
.size[CAN_RAM_MODE_CANFD] = sizeof(struct mcp251xfd_hw_rx_obj_canfd),
.min = MCP251XFD_RX_OBJ_NUM_MIN,
.max = MCP251XFD_RX_OBJ_NUM_MAX,
.def[CAN_RAM_MODE_CAN] = CAN_RAM_NUM_MAX,
.def[CAN_RAM_MODE_CANFD] = CAN_RAM_NUM_MAX,
.fifo_num = MCP251XFD_FIFO_RX_NUM,
.fifo_depth_min = MCP251XFD_RX_FIFO_DEPTH_MIN,
.fifo_depth_coalesce_min = MCP251XFD_RX_FIFO_DEPTH_COALESCE_MIN,
},
.tx = {
.size[CAN_RAM_MODE_CAN] = sizeof(struct mcp251xfd_hw_tef_obj) +
sizeof(struct mcp251xfd_hw_tx_obj_can),
.size[CAN_RAM_MODE_CANFD] = sizeof(struct mcp251xfd_hw_tef_obj) +
sizeof(struct mcp251xfd_hw_tx_obj_canfd),
.min = MCP251XFD_TX_OBJ_NUM_MIN,
.max = MCP251XFD_TX_OBJ_NUM_MAX,
.def[CAN_RAM_MODE_CAN] = MCP251XFD_TX_OBJ_NUM_CAN_DEFAULT,
.def[CAN_RAM_MODE_CANFD] = MCP251XFD_TX_OBJ_NUM_CANFD_DEFAULT,
.fifo_num = MCP251XFD_FIFO_TX_NUM,
.fifo_depth_min = MCP251XFD_TX_FIFO_DEPTH_MIN,
.fifo_depth_coalesce_min = MCP251XFD_TX_FIFO_DEPTH_COALESCE_MIN,
},
.size = MCP251XFD_RAM_SIZE,
.fifo_depth = MCP251XFD_FIFO_DEPTH,
};
int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
{
const bool fd_mode = mcp251xfd_is_fd_mode(priv);
struct mcp251xfd_tx_ring *tx_ring = priv->tx;
struct mcp251xfd_rx_ring *rx_ring;
u8 tx_obj_size, rx_obj_size;
u8 rem, i;
/* switching from CAN-2.0 to CAN-FD mode or vice versa */
if (fd_mode != test_bit(MCP251XFD_FLAGS_FD_MODE, priv->flags)) {
struct can_ram_layout layout;
can_ram_get_layout(&layout, &mcp251xfd_ram_config, NULL, NULL, fd_mode);
priv->rx_obj_num = layout.default_rx;
tx_ring->obj_num = layout.default_tx;
}
if (fd_mode) {
tx_obj_size = sizeof(struct mcp251xfd_hw_tx_obj_canfd);
rx_obj_size = sizeof(struct mcp251xfd_hw_rx_obj_canfd);
set_bit(MCP251XFD_FLAGS_FD_MODE, priv->flags);
} else {
tx_obj_size = sizeof(struct mcp251xfd_hw_tx_obj_can);
rx_obj_size = sizeof(struct mcp251xfd_hw_rx_obj_can);
clear_bit(MCP251XFD_FLAGS_FD_MODE, priv->flags);
}
tx_ring->obj_size = tx_obj_size;
rem = priv->rx_obj_num;
for (i = 0; i < ARRAY_SIZE(priv->rx) && rem; i++) {
u8 rx_obj_num;
if (i == 0 && priv->rx_obj_num_coalesce_irq)
rx_obj_num = min_t(u8, priv->rx_obj_num_coalesce_irq * 2,
MCP251XFD_FIFO_DEPTH);
else
rx_obj_num = min_t(u8, rounddown_pow_of_two(rem),
MCP251XFD_FIFO_DEPTH);
rem -= rx_obj_num;
rx_ring = kzalloc(sizeof(*rx_ring) + rx_obj_size * rx_obj_num,
GFP_KERNEL);
if (!rx_ring) {
mcp251xfd_ring_free(priv);
return -ENOMEM;
}
rx_ring->obj_num = rx_obj_num;
rx_ring->obj_size = rx_obj_size;
priv->rx[i] = rx_ring;
}
priv->rx_ring_num = i;
hrtimer_init(&priv->rx_irq_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
priv->rx_irq_timer.function = mcp251xfd_rx_irq_timer;
hrtimer_init(&priv->tx_irq_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
priv->tx_irq_timer.function = mcp251xfd_tx_irq_timer;
return 0;
}