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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c')
-rw-r--r--drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c266
1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c
new file mode 100644
index 000000000..237617b0c
--- /dev/null
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c
@@ -0,0 +1,266 @@
+// 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 <linux/bitfield.h>
+
+#include "mcp251xfd.h"
+
+static inline int
+mcp251xfd_tef_tail_get_from_chip(const struct mcp251xfd_priv *priv,
+ u8 *tef_tail)
+{
+ u32 tef_ua;
+ int err;
+
+ err = regmap_read(priv->map_reg, MCP251XFD_REG_TEFUA, &tef_ua);
+ if (err)
+ return err;
+
+ *tef_tail = tef_ua / sizeof(struct mcp251xfd_hw_tef_obj);
+
+ return 0;
+}
+
+static int mcp251xfd_check_tef_tail(const struct mcp251xfd_priv *priv)
+{
+ u8 tef_tail_chip, tef_tail;
+ int err;
+
+ if (!IS_ENABLED(CONFIG_CAN_MCP251XFD_SANITY))
+ return 0;
+
+ err = mcp251xfd_tef_tail_get_from_chip(priv, &tef_tail_chip);
+ if (err)
+ return err;
+
+ tef_tail = mcp251xfd_get_tef_tail(priv);
+ if (tef_tail_chip != tef_tail) {
+ netdev_err(priv->ndev,
+ "TEF tail of chip (0x%02x) and ours (0x%08x) inconsistent.\n",
+ tef_tail_chip, tef_tail);
+ return -EILSEQ;
+ }
+
+ return 0;
+}
+
+static int
+mcp251xfd_handle_tefif_recover(const struct mcp251xfd_priv *priv, const u32 seq)
+{
+ const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
+ u32 tef_sta;
+ int err;
+
+ err = regmap_read(priv->map_reg, MCP251XFD_REG_TEFSTA, &tef_sta);
+ if (err)
+ return err;
+
+ if (tef_sta & MCP251XFD_REG_TEFSTA_TEFOVIF) {
+ netdev_err(priv->ndev,
+ "Transmit Event FIFO buffer overflow.\n");
+ return -ENOBUFS;
+ }
+
+ netdev_info(priv->ndev,
+ "Transmit Event FIFO buffer %s. (seq=0x%08x, tef_tail=0x%08x, tef_head=0x%08x, tx_head=0x%08x).\n",
+ tef_sta & MCP251XFD_REG_TEFSTA_TEFFIF ?
+ "full" : tef_sta & MCP251XFD_REG_TEFSTA_TEFNEIF ?
+ "not empty" : "empty",
+ seq, priv->tef->tail, priv->tef->head, tx_ring->head);
+
+ /* The Sequence Number in the TEF doesn't match our tef_tail. */
+ return -EAGAIN;
+}
+
+static int
+mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
+ const struct mcp251xfd_hw_tef_obj *hw_tef_obj,
+ unsigned int *frame_len_ptr)
+{
+ struct net_device_stats *stats = &priv->ndev->stats;
+ struct sk_buff *skb;
+ u32 seq, seq_masked, tef_tail_masked, tef_tail;
+
+ seq = FIELD_GET(MCP251XFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK,
+ hw_tef_obj->flags);
+
+ /* Use the MCP2517FD mask on the MCP2518FD, too. We only
+ * compare 7 bits, this should be enough to detect
+ * net-yet-completed, i.e. old TEF objects.
+ */
+ seq_masked = seq &
+ field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
+ tef_tail_masked = priv->tef->tail &
+ field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
+ if (seq_masked != tef_tail_masked)
+ return mcp251xfd_handle_tefif_recover(priv, seq);
+
+ tef_tail = mcp251xfd_get_tef_tail(priv);
+ skb = priv->can.echo_skb[tef_tail];
+ if (skb)
+ mcp251xfd_skb_set_timestamp(priv, skb, hw_tef_obj->ts);
+ stats->tx_bytes +=
+ can_rx_offload_get_echo_skb(&priv->offload,
+ tef_tail, hw_tef_obj->ts,
+ frame_len_ptr);
+ stats->tx_packets++;
+ priv->tef->tail++;
+
+ return 0;
+}
+
+static int mcp251xfd_tef_ring_update(struct mcp251xfd_priv *priv)
+{
+ const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
+ unsigned int new_head;
+ u8 chip_tx_tail;
+ int err;
+
+ err = mcp251xfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
+ if (err)
+ return err;
+
+ /* chip_tx_tail, is the next TX-Object send by the HW.
+ * The new TEF head must be >= the old head, ...
+ */
+ new_head = round_down(priv->tef->head, tx_ring->obj_num) + chip_tx_tail;
+ if (new_head <= priv->tef->head)
+ new_head += tx_ring->obj_num;
+
+ /* ... but it cannot exceed the TX head. */
+ priv->tef->head = min(new_head, tx_ring->head);
+
+ return mcp251xfd_check_tef_tail(priv);
+}
+
+static inline int
+mcp251xfd_tef_obj_read(const struct mcp251xfd_priv *priv,
+ struct mcp251xfd_hw_tef_obj *hw_tef_obj,
+ const u8 offset, const u8 len)
+{
+ const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
+ const int val_bytes = regmap_get_val_bytes(priv->map_rx);
+
+ if (IS_ENABLED(CONFIG_CAN_MCP251XFD_SANITY) &&
+ (offset > tx_ring->obj_num ||
+ len > tx_ring->obj_num ||
+ offset + len > tx_ring->obj_num)) {
+ netdev_err(priv->ndev,
+ "Trying to read too many TEF objects (max=%d, offset=%d, len=%d).\n",
+ tx_ring->obj_num, offset, len);
+ return -ERANGE;
+ }
+
+ return regmap_bulk_read(priv->map_rx,
+ mcp251xfd_get_tef_obj_addr(offset),
+ hw_tef_obj,
+ sizeof(*hw_tef_obj) / val_bytes * len);
+}
+
+static inline void mcp251xfd_ecc_tefif_successful(struct mcp251xfd_priv *priv)
+{
+ struct mcp251xfd_ecc *ecc = &priv->ecc;
+
+ ecc->ecc_stat = 0;
+}
+
+int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
+{
+ struct mcp251xfd_hw_tef_obj hw_tef_obj[MCP251XFD_TX_OBJ_NUM_MAX];
+ unsigned int total_frame_len = 0;
+ u8 tef_tail, len, l;
+ int err, i;
+
+ err = mcp251xfd_tef_ring_update(priv);
+ if (err)
+ return err;
+
+ tef_tail = mcp251xfd_get_tef_tail(priv);
+ len = mcp251xfd_get_tef_len(priv);
+ l = mcp251xfd_get_tef_linear_len(priv);
+ err = mcp251xfd_tef_obj_read(priv, hw_tef_obj, tef_tail, l);
+ if (err)
+ return err;
+
+ if (l < len) {
+ err = mcp251xfd_tef_obj_read(priv, &hw_tef_obj[l], 0, len - l);
+ if (err)
+ return err;
+ }
+
+ for (i = 0; i < len; i++) {
+ unsigned int frame_len = 0;
+
+ err = mcp251xfd_handle_tefif_one(priv, &hw_tef_obj[i], &frame_len);
+ /* -EAGAIN means the Sequence Number in the TEF
+ * doesn't match our tef_tail. This can happen if we
+ * read the TEF objects too early. Leave loop let the
+ * interrupt handler call us again.
+ */
+ if (err == -EAGAIN)
+ goto out_netif_wake_queue;
+ if (err)
+ return err;
+
+ total_frame_len += frame_len;
+ }
+
+ out_netif_wake_queue:
+ len = i; /* number of handled goods TEFs */
+ if (len) {
+ struct mcp251xfd_tef_ring *ring = priv->tef;
+ struct mcp251xfd_tx_ring *tx_ring = priv->tx;
+ int offset;
+
+ /* Increment the TEF FIFO tail pointer 'len' times in
+ * a single SPI message.
+ *
+ * Note:
+ * Calculate offset, so that the SPI transfer ends on
+ * the last message of the uinc_xfer array, which has
+ * "cs_change == 0", to properly deactivate the chip
+ * select.
+ */
+ offset = ARRAY_SIZE(ring->uinc_xfer) - len;
+ err = spi_sync_transfer(priv->spi,
+ ring->uinc_xfer + offset, len);
+ if (err)
+ return err;
+
+ tx_ring->tail += len;
+ netdev_completed_queue(priv->ndev, len, total_frame_len);
+
+ err = mcp251xfd_check_tef_tail(priv);
+ if (err)
+ return err;
+ }
+
+ mcp251xfd_ecc_tefif_successful(priv);
+
+ if (mcp251xfd_get_tx_free(priv->tx)) {
+ /* Make sure that anybody stopping the queue after
+ * this sees the new tx_ring->tail.
+ */
+ smp_mb();
+ netif_wake_queue(priv->ndev);
+ }
+
+ if (priv->tx_coalesce_usecs_irq)
+ hrtimer_start(&priv->tx_irq_timer,
+ ns_to_ktime(priv->tx_coalesce_usecs_irq *
+ NSEC_PER_USEC),
+ HRTIMER_MODE_REL);
+
+ return 0;
+}