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authorMarc Kleine-Budde <mkl@pengutronix.de>2015-09-01 09:00:13 +0200
committerMarc Kleine-Budde <mkl@pengutronix.de>2017-02-06 15:13:44 +0100
commitb3cf53e988cedb11a407d65abafca836da78b7c9 (patch)
treed6dc8e05039b775cfdf198a2623ef4dc2f1202ca /drivers
parent9eb7aa891101a4a09114ff3191f9877ea35eae06 (diff)
can: flexcan: add support for timestamp based rx-offload
The flexcan IP core has 64 mailboxes. For now they are configured for RX as a hardware FIFO. This FIFO has a fixed depth of 6 CAN frames. In some high load scenarios it turns out thas this buffer is too small. In order to have a buffer larger than the 6 frames FIFO, this patch adds support for timestamp based offloading via the generic rx-offload infrastructure. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/can/flexcan.c158
1 files changed, 129 insertions, 29 deletions
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index a0fdced0e849..6c84afed5e6c 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -3,7 +3,8 @@
*
* Copyright (c) 2005-2006 Varma Electronics Oy
* Copyright (c) 2009 Sascha Hauer, Pengutronix
- * Copyright (c) 2010 Marc Kleine-Budde, Pengutronix
+ * Copyright (c) 2010-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+ * Copyright (c) 2014 David Jander, Protonic Holland
*
* Based on code originally by Andrey Volkov <avolkov@varma-el.com>
*
@@ -59,6 +60,7 @@
#define FLEXCAN_MCR_IRMQ BIT(16)
#define FLEXCAN_MCR_LPRIO_EN BIT(13)
#define FLEXCAN_MCR_AEN BIT(12)
+/* MCR_MAXMB: maximum used MBs is MAXMB + 1 */
#define FLEXCAN_MCR_MAXMB(x) ((x) & 0x7f)
#define FLEXCAN_MCR_IDAM_A (0x0 << 8)
#define FLEXCAN_MCR_IDAM_B (0x1 << 8)
@@ -146,12 +148,18 @@
/* Errata ERR005829 step7: Reserve first valid MB */
#define FLEXCAN_TX_MB_RESERVED_OFF_FIFO 8
#define FLEXCAN_TX_MB_OFF_FIFO 9
+#define FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP 0
+#define FLEXCAN_TX_MB_OFF_TIMESTAMP 1
+#define FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST (FLEXCAN_TX_MB_OFF_TIMESTAMP + 1)
+#define FLEXCAN_RX_MB_OFF_TIMESTAMP_LAST 63
#define FLEXCAN_IFLAG_MB(x) BIT(x)
#define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW BIT(7)
#define FLEXCAN_IFLAG_RX_FIFO_WARN BIT(6)
#define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE BIT(5)
/* FLEXCAN message buffers */
+#define FLEXCAN_MB_CODE_MASK (0xf << 24)
+#define FLEXCAN_MB_CODE_RX_BUSY_BIT (0x1 << 24)
#define FLEXCAN_MB_CODE_RX_INACTIVE (0x0 << 24)
#define FLEXCAN_MB_CODE_RX_EMPTY (0x4 << 24)
#define FLEXCAN_MB_CODE_RX_FULL (0x2 << 24)
@@ -189,6 +197,7 @@
#define FLEXCAN_QUIRK_DISABLE_RXFG BIT(2) /* Disable RX FIFO Global mask */
#define FLEXCAN_QUIRK_ENABLE_EACEN_RRS BIT(3) /* Enable EACEN and RRS bit in ctrl2 */
#define FLEXCAN_QUIRK_DISABLE_MECR BIT(4) /* Disble Memory error detection */
+#define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP BIT(5) /* Use timestamp based offloading */
/* Structure of the message buffer */
struct flexcan_mb {
@@ -263,6 +272,7 @@ struct flexcan_priv {
u8 tx_mb_idx;
u32 reg_ctrl_default;
u32 reg_imask1_default;
+ u32 reg_imask2_default;
struct clk *clk_ipg;
struct clk *clk_per;
@@ -624,11 +634,32 @@ static unsigned int flexcan_mailbox_read(struct can_rx_offload *offload,
struct flexcan_mb __iomem *mb = &regs->mb[n];
u32 reg_ctrl, reg_id, reg_iflag1;
- reg_iflag1 = flexcan_read(&regs->iflag1);
- if (!(reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE))
- return 0;
+ if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+ u32 code;
+
+ do {
+ reg_ctrl = flexcan_read(&mb->can_ctrl);
+ } while (reg_ctrl & FLEXCAN_MB_CODE_RX_BUSY_BIT);
+
+ /* is this MB empty? */
+ code = reg_ctrl & FLEXCAN_MB_CODE_MASK;
+ if ((code != FLEXCAN_MB_CODE_RX_FULL) &&
+ (code != FLEXCAN_MB_CODE_RX_OVERRUN))
+ return 0;
+
+ if (code == FLEXCAN_MB_CODE_RX_OVERRUN) {
+ /* This MB was overrun, we lost data */
+ offload->dev->stats.rx_over_errors++;
+ offload->dev->stats.rx_errors++;
+ }
+ } else {
+ reg_iflag1 = flexcan_read(&regs->iflag1);
+ if (!(reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE))
+ return 0;
+
+ reg_ctrl = flexcan_read(&mb->can_ctrl);
+ }
- reg_ctrl = flexcan_read(&mb->can_ctrl);
/* increase timstamp to full 32 bit */
*timestamp = reg_ctrl << 16;
@@ -646,12 +677,33 @@ static unsigned int flexcan_mailbox_read(struct can_rx_offload *offload,
*(__be32 *)(cf->data + 4) = cpu_to_be32(flexcan_read(&mb->data[1]));
/* mark as read */
- flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
- flexcan_read(&regs->timer);
+ if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+ /* Clear IRQ */
+ if (n < 32)
+ flexcan_write(BIT(n), &regs->iflag1);
+ else
+ flexcan_write(BIT(n - 32), &regs->iflag2);
+ } else {
+ flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
+ flexcan_read(&regs->timer);
+ }
return 1;
}
+
+static inline u64 flexcan_read_reg_iflag_rx(struct flexcan_priv *priv)
+{
+ struct flexcan_regs __iomem *regs = priv->regs;
+ u32 iflag1, iflag2;
+
+ iflag2 = flexcan_read(&regs->iflag2) & priv->reg_imask2_default;
+ iflag1 = flexcan_read(&regs->iflag1) & priv->reg_imask1_default &
+ ~FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
+
+ return (u64)iflag2 << 32 | iflag1;
+}
+
static irqreturn_t flexcan_irq(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
@@ -664,17 +716,30 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
reg_iflag1 = flexcan_read(&regs->iflag1);
/* reception interrupt */
- if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) {
- handled = IRQ_HANDLED;
- can_rx_offload_irq_offload_fifo(&priv->offload);
- }
+ if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+ u64 reg_iflag;
+ int ret;
+
+ while ((reg_iflag = flexcan_read_reg_iflag_rx(priv))) {
+ handled = IRQ_HANDLED;
+ ret = can_rx_offload_irq_offload_timestamp(&priv->offload,
+ reg_iflag);
+ if (!ret)
+ break;
+ }
+ } else {
+ if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) {
+ handled = IRQ_HANDLED;
+ can_rx_offload_irq_offload_fifo(&priv->offload);
+ }
- /* FIFO overflow interrupt */
- if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
- handled = IRQ_HANDLED;
- flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);
- dev->stats.rx_over_errors++;
- dev->stats.rx_errors++;
+ /* FIFO overflow interrupt */
+ if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
+ handled = IRQ_HANDLED;
+ flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);
+ dev->stats.rx_over_errors++;
+ dev->stats.rx_errors++;
+ }
}
/* transmission complete interrupt */
@@ -787,10 +852,17 @@ static int flexcan_chip_start(struct net_device *dev)
*/
reg_mcr = flexcan_read(&regs->mcr);
reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
- reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
- FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_SRX_DIS |
- FLEXCAN_MCR_IRMQ | FLEXCAN_MCR_IDAM_C |
- FLEXCAN_MCR_MAXMB(priv->tx_mb_idx);
+ reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV |
+ FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_SRX_DIS | FLEXCAN_MCR_IRMQ |
+ FLEXCAN_MCR_IDAM_C;
+
+ if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+ reg_mcr &= ~FLEXCAN_MCR_FEN;
+ reg_mcr |= FLEXCAN_MCR_MAXMB(priv->offload.mb_last);
+ } else {
+ reg_mcr |= FLEXCAN_MCR_FEN |
+ FLEXCAN_MCR_MAXMB(priv->tx_mb_idx);
+ }
netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
flexcan_write(reg_mcr, &regs->mcr);
@@ -839,6 +911,12 @@ static int flexcan_chip_start(struct net_device *dev)
&regs->mb[i].can_ctrl);
}
+ if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+ for (i = priv->offload.mb_first; i <= priv->offload.mb_last; i++)
+ flexcan_write(FLEXCAN_MB_CODE_RX_EMPTY,
+ &regs->mb[i].can_ctrl);
+ }
+
/* Errata ERR005829: mark first TX mailbox as INACTIVE */
flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
&priv->tx_mb_reserved->can_ctrl);
@@ -897,6 +975,7 @@ static int flexcan_chip_start(struct net_device *dev)
disable_irq(dev->irq);
flexcan_write(priv->reg_ctrl_default, &regs->ctrl);
flexcan_write(priv->reg_imask1_default, &regs->imask1);
+ flexcan_write(priv->reg_imask2_default, &regs->imask2);
enable_irq(dev->irq);
/* print chip status */
@@ -926,6 +1005,7 @@ static void flexcan_chip_stop(struct net_device *dev)
flexcan_chip_disable(priv);
/* Disable all interrupts */
+ flexcan_write(0, &regs->imask2);
flexcan_write(0, &regs->imask1);
flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
&regs->ctrl);
@@ -1058,8 +1138,9 @@ static int register_flexcandev(struct net_device *dev)
flexcan_write(reg, &regs->mcr);
/* Currently we only support newer versions of this core
- * featuring a RX FIFO. Older cores found on some Coldfire
- * derivates are not yet supported.
+ * featuring a RX hardware FIFO (although this driver doesn't
+ * make use of it on some cores). Older cores, found on some
+ * Coldfire derivates are not tested.
*/
reg = flexcan_read(&regs->mcr);
if (!(reg & FLEXCAN_MCR_FEN)) {
@@ -1183,17 +1264,36 @@ static int flexcan_probe(struct platform_device *pdev)
priv->devtype_data = devtype_data;
priv->reg_xceiver = reg_xceiver;
- priv->tx_mb_idx = FLEXCAN_TX_MB_OFF_FIFO;
- priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_FIFO];
+ if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+ priv->tx_mb_idx = FLEXCAN_TX_MB_OFF_TIMESTAMP;
+ priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP];
+ } else {
+ priv->tx_mb_idx = FLEXCAN_TX_MB_OFF_FIFO;
+ priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_FIFO];
+ }
priv->tx_mb = &regs->mb[priv->tx_mb_idx];
- priv->reg_imask1_default = FLEXCAN_IFLAG_RX_FIFO_OVERFLOW |
- FLEXCAN_IFLAG_RX_FIFO_AVAILABLE |
- FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
+ priv->reg_imask1_default = FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
+ priv->reg_imask2_default = 0;
priv->offload.mailbox_read = flexcan_mailbox_read;
- err = can_rx_offload_add_fifo(dev, &priv->offload, FLEXCAN_NAPI_WEIGHT);
+ if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+ u64 imask;
+
+ priv->offload.mb_first = FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST;
+ priv->offload.mb_last = FLEXCAN_RX_MB_OFF_TIMESTAMP_LAST;
+
+ imask = GENMASK_ULL(priv->offload.mb_last, priv->offload.mb_first);
+ priv->reg_imask1_default |= imask;
+ priv->reg_imask2_default |= imask >> 32;
+
+ err = can_rx_offload_add_timestamp(dev, &priv->offload);
+ } else {
+ priv->reg_imask1_default |= FLEXCAN_IFLAG_RX_FIFO_OVERFLOW |
+ FLEXCAN_IFLAG_RX_FIFO_AVAILABLE;
+ err = can_rx_offload_add_fifo(dev, &priv->offload, FLEXCAN_NAPI_WEIGHT);
+ }
if (err)
goto failed_offload;