Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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;
+}