[PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime

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* [PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime
@ 2022-01-07 19:30 Marc Kleine-Budde
  2022-01-07 19:30 ` [PATCH v3 1/7] can: flexcan: move driver into separate sub directory Marc Kleine-Budde
                   ` (6 more replies)
  0 siblings, 7 replies; 10+ messages in thread
From: Marc Kleine-Budde @ 2022-01-07 19:30 UTC (permalink / raw)
  To: linux-can; +Cc: Dario Binacchi

Hello,

Here's the v2 of Dario's and my patches to switch of RTR reception to
make use of bigger RX buffer:

Show available private flags:

| $ sudo ethtool --show-priv-flags can0
| Private flags for can0:
| rx-rtr: on

Change private flag:

| $ sudo ethtool --set-priv-flags can0 rx-rtr off
| netlink error: Device or resource busy

...does not work if interface is up.

Shut down interface and change "rx-rtr":

| $ sudo ip link set dev can0 down
| $ sudo ethtool --set-priv-flags can0 rx-rtr off
| $ sudo ethtool --show-priv-flags can0
| Private flags for can0:
| rx-rtr: off

regards,
Marc

Changes since v2:
- add missing variable initialization, tnx Dario
- renamed flag rx-fifo -> rx-rtr
- renamed existing quirks
- added more quirks to describe controller
- added Dario's documentation patches

Changes since RFC:
- move driver into subdir
- replaced memcpy() by direct assignment, do this earlier
- use priv->devtype_data.quirks where possible
- rename flexcan_main.c -> flexcan-core.c
  (mcp251xfd and tcan4x5x driver have the same naming scheme)
- use copyright notice from flexcan.c in flexcan.h
- add private flag support to set rx-fifo
- remove drvinfo, the kernel will fall back to the default implementation





^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v3 1/7] can: flexcan: move driver into separate sub directory
  2022-01-07 19:30 [PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime Marc Kleine-Budde
@ 2022-01-07 19:30 ` Marc Kleine-Budde
  2022-01-07 19:31 ` [PATCH v3 2/7] can: flexcan: allow to change quirks at runtime Marc Kleine-Budde
                   ` (5 subsequent siblings)
  6 siblings, 0 replies; 10+ messages in thread
From: Marc Kleine-Budde @ 2022-01-07 19:30 UTC (permalink / raw)
  To: linux-can; +Cc: Dario Binacchi, Marc Kleine-Budde

This patch moves the flexcan driver into a separate directory, a later
patch will add more files.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/Makefile                              | 2 +-
 drivers/net/can/flexcan/Makefile                      | 6 ++++++
 drivers/net/can/{flexcan.c => flexcan/flexcan-core.c} | 0
 3 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 drivers/net/can/flexcan/Makefile
 rename drivers/net/can/{flexcan.c => flexcan/flexcan-core.c} (100%)

diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index a2b4463d8480..1e660afcb61b 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -16,7 +16,7 @@ obj-y				+= softing/
 obj-$(CONFIG_CAN_AT91)		+= at91_can.o
 obj-$(CONFIG_CAN_CC770)		+= cc770/
 obj-$(CONFIG_CAN_C_CAN)		+= c_can/
-obj-$(CONFIG_CAN_FLEXCAN)	+= flexcan.o
+obj-$(CONFIG_CAN_FLEXCAN)	+= flexcan/
 obj-$(CONFIG_CAN_GRCAN)		+= grcan.o
 obj-$(CONFIG_CAN_IFI_CANFD)	+= ifi_canfd/
 obj-$(CONFIG_CAN_JANZ_ICAN3)	+= janz-ican3.o
diff --git a/drivers/net/can/flexcan/Makefile b/drivers/net/can/flexcan/Makefile
new file mode 100644
index 000000000000..25dd1d12b866
--- /dev/null
+++ b/drivers/net/can/flexcan/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_CAN_FLEXCAN) += flexcan.o
+
+flexcan-objs :=
+flexcan-objs += flexcan-core.o
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan/flexcan-core.c
similarity index 100%
rename from drivers/net/can/flexcan.c
rename to drivers/net/can/flexcan/flexcan-core.c
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v3 2/7] can: flexcan: allow to change quirks at runtime
  2022-01-07 19:30 [PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime Marc Kleine-Budde
  2022-01-07 19:30 ` [PATCH v3 1/7] can: flexcan: move driver into separate sub directory Marc Kleine-Budde
@ 2022-01-07 19:31 ` Marc Kleine-Budde
  2022-01-07 19:31 ` [PATCH v3 3/7] can: flexcan: rename RX modes Marc Kleine-Budde
                   ` (4 subsequent siblings)
  6 siblings, 0 replies; 10+ messages in thread
From: Marc Kleine-Budde @ 2022-01-07 19:31 UTC (permalink / raw)
  To: linux-can; +Cc: Dario Binacchi, Marc Kleine-Budde

From: Dario Binacchi <dario.binacchi@amarulasolutions.com>

This is a preparation patch for the upcoming support to change the
rx-rtr capability via the ethtool API.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/flexcan/flexcan-core.c | 54 +++++++++++++-------------
 1 file changed, 27 insertions(+), 27 deletions(-)

diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index 12b60ad95b02..26bf0a0a72f1 100644
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -369,7 +369,7 @@ struct flexcan_priv {
 
 	struct clk *clk_ipg;
 	struct clk *clk_per;
-	const struct flexcan_devtype_data *devtype_data;
+	struct flexcan_devtype_data devtype_data;
 	struct regulator *reg_xceiver;
 	struct flexcan_stop_mode stm;
 
@@ -600,7 +600,7 @@ static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
 	priv->write(reg_mcr, &regs->mcr);
 
 	/* enable stop request */
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
 		ret = flexcan_stop_mode_enable_scfw(priv, true);
 		if (ret < 0)
 			return ret;
@@ -619,7 +619,7 @@ static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv)
 	int ret;
 
 	/* remove stop request */
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
 		ret = flexcan_stop_mode_enable_scfw(priv, false);
 		if (ret < 0)
 			return ret;
@@ -1022,7 +1022,7 @@ static struct sk_buff *flexcan_mailbox_read(struct can_rx_offload *offload,
 
 	mb = flexcan_get_mb(priv, n);
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
 		u32 code;
 
 		do {
@@ -1087,7 +1087,7 @@ static struct sk_buff *flexcan_mailbox_read(struct can_rx_offload *offload,
 	}
 
  mark_as_read:
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
 		flexcan_write64(priv, FLEXCAN_IFLAG_MB(n), &regs->iflag1);
 	else
 		priv->write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
@@ -1113,7 +1113,7 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 	enum can_state last_state = priv->can.state;
 
 	/* reception interrupt */
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
 		u64 reg_iflag_rx;
 		int ret;
 
@@ -1173,7 +1173,7 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 
 	/* state change interrupt or broken error state quirk fix is enabled */
 	if ((reg_esr & FLEXCAN_ESR_ERR_STATE) ||
-	    (priv->devtype_data->quirks & (FLEXCAN_QUIRK_BROKEN_WERR_STATE |
+	    (priv->devtype_data.quirks & (FLEXCAN_QUIRK_BROKEN_WERR_STATE |
 					   FLEXCAN_QUIRK_BROKEN_PERR_STATE)))
 		flexcan_irq_state(dev, reg_esr);
 
@@ -1195,11 +1195,11 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 	 * (1): enabled if FLEXCAN_QUIRK_BROKEN_WERR_STATE is enabled
 	 */
 	if ((last_state != priv->can.state) &&
-	    (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_PERR_STATE) &&
+	    (priv->devtype_data.quirks & FLEXCAN_QUIRK_BROKEN_PERR_STATE) &&
 	    !(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
 		switch (priv->can.state) {
 		case CAN_STATE_ERROR_ACTIVE:
-			if (priv->devtype_data->quirks &
+			if (priv->devtype_data.quirks &
 			    FLEXCAN_QUIRK_BROKEN_WERR_STATE)
 				flexcan_error_irq_enable(priv);
 			else
@@ -1423,13 +1423,13 @@ static int flexcan_rx_offload_setup(struct net_device *dev)
 	else
 		priv->mb_size = sizeof(struct flexcan_mb) + CAN_MAX_DLEN;
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_NR_MB_16)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_MB_16)
 		priv->mb_count = 16;
 	else
 		priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
 				 (sizeof(priv->regs->mb[1]) / priv->mb_size);
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
 		priv->tx_mb_reserved =
 			flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP);
 	else
@@ -1441,7 +1441,7 @@ static int flexcan_rx_offload_setup(struct net_device *dev)
 
 	priv->offload.mailbox_read = flexcan_mailbox_read;
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
 		priv->offload.mb_first = FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST;
 		priv->offload.mb_last = priv->mb_count - 2;
 
@@ -1506,7 +1506,7 @@ static int flexcan_chip_start(struct net_device *dev)
 	if (err)
 		goto out_chip_disable;
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_ECC)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SUPPORT_ECC)
 		flexcan_ram_init(dev);
 
 	flexcan_set_bittiming(dev);
@@ -1535,7 +1535,7 @@ static int flexcan_chip_start(struct net_device *dev)
 	 * - disable for timestamp mode
 	 * - enable for FIFO mode
 	 */
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
 		reg_mcr &= ~FLEXCAN_MCR_FEN;
 	else
 		reg_mcr |= FLEXCAN_MCR_FEN;
@@ -1586,7 +1586,7 @@ static int flexcan_chip_start(struct net_device *dev)
 	 * on most Flexcan cores, too. Otherwise we don't get
 	 * any error warning or passive interrupts.
 	 */
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_WERR_STATE ||
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_BROKEN_WERR_STATE ||
 	    priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
 		reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
 	else
@@ -1599,7 +1599,7 @@ static int flexcan_chip_start(struct net_device *dev)
 	netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
 	priv->write(reg_ctrl, &regs->ctrl);
 
-	if ((priv->devtype_data->quirks & FLEXCAN_QUIRK_ENABLE_EACEN_RRS)) {
+	if ((priv->devtype_data.quirks & FLEXCAN_QUIRK_ENABLE_EACEN_RRS)) {
 		reg_ctrl2 = priv->read(&regs->ctrl2);
 		reg_ctrl2 |= FLEXCAN_CTRL2_EACEN | FLEXCAN_CTRL2_RRS;
 		priv->write(reg_ctrl2, &regs->ctrl2);
@@ -1631,7 +1631,7 @@ static int flexcan_chip_start(struct net_device *dev)
 		priv->write(reg_fdctrl, &regs->fdctrl);
 	}
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
 		for (i = priv->offload.mb_first; i <= priv->offload.mb_last; i++) {
 			mb = flexcan_get_mb(priv, i);
 			priv->write(FLEXCAN_MB_CODE_RX_EMPTY,
@@ -1659,7 +1659,7 @@ static int flexcan_chip_start(struct net_device *dev)
 	priv->write(0x0, &regs->rx14mask);
 	priv->write(0x0, &regs->rx15mask);
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_RXFG)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_DISABLE_RXFG)
 		priv->write(0x0, &regs->rxfgmask);
 
 	/* clear acceptance filters */
@@ -1673,7 +1673,7 @@ static int flexcan_chip_start(struct net_device *dev)
 	 * This also works around errata e5295 which generates false
 	 * positive memory errors and put the device in freeze mode.
 	 */
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_MECR) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_DISABLE_MECR) {
 		/* Follow the protocol as described in "Detection
 		 * and Correction of Memory Errors" to write to
 		 * MECR register (step 1 - 5)
@@ -1799,7 +1799,7 @@ static int flexcan_open(struct net_device *dev)
 	if (err)
 		goto out_can_rx_offload_disable;
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
 		err = request_irq(priv->irq_boff,
 				  flexcan_irq, IRQF_SHARED, dev->name, dev);
 		if (err)
@@ -1845,7 +1845,7 @@ static int flexcan_close(struct net_device *dev)
 	netif_stop_queue(dev);
 	flexcan_chip_interrupts_disable(dev);
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
 		free_irq(priv->irq_err, dev);
 		free_irq(priv->irq_boff, dev);
 	}
@@ -2051,9 +2051,9 @@ static int flexcan_setup_stop_mode(struct platform_device *pdev)
 
 	priv = netdev_priv(dev);
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW)
 		ret = flexcan_setup_stop_mode_scfw(pdev);
-	else if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR)
+	else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR)
 		ret = flexcan_setup_stop_mode_gpr(pdev);
 	else
 		/* return 0 directly if doesn't support stop mode feature */
@@ -2181,9 +2181,10 @@ static int flexcan_probe(struct platform_device *pdev)
 	dev->flags |= IFF_ECHO;
 
 	priv = netdev_priv(dev);
+	priv->devtype_data = *devtype_data;
 
 	if (of_property_read_bool(pdev->dev.of_node, "big-endian") ||
-	    devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN) {
+	    priv->devtype_data.quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN) {
 		priv->read = flexcan_read_be;
 		priv->write = flexcan_write_be;
 	} else {
@@ -2202,10 +2203,9 @@ static int flexcan_probe(struct platform_device *pdev)
 	priv->clk_ipg = clk_ipg;
 	priv->clk_per = clk_per;
 	priv->clk_src = clk_src;
-	priv->devtype_data = devtype_data;
 	priv->reg_xceiver = reg_xceiver;
 
-	if (devtype_data->quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
 		priv->irq_boff = platform_get_irq(pdev, 1);
 		if (priv->irq_boff <= 0) {
 			err = -ENODEV;
@@ -2218,7 +2218,7 @@ static int flexcan_probe(struct platform_device *pdev)
 		}
 	}
 
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_FD) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SUPPORT_FD) {
 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD |
 			CAN_CTRLMODE_FD_NON_ISO;
 		priv->can.bittiming_const = &flexcan_fd_bittiming_const;
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v3 3/7] can: flexcan: rename RX modes
  2022-01-07 19:30 [PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime Marc Kleine-Budde
  2022-01-07 19:30 ` [PATCH v3 1/7] can: flexcan: move driver into separate sub directory Marc Kleine-Budde
  2022-01-07 19:31 ` [PATCH v3 2/7] can: flexcan: allow to change quirks at runtime Marc Kleine-Budde
@ 2022-01-07 19:31 ` Marc Kleine-Budde
  2022-01-07 19:31 ` [PATCH v3 4/7] can: flexcan: add more quirks to describe RX path capabilities Marc Kleine-Budde
                   ` (3 subsequent siblings)
  6 siblings, 0 replies; 10+ messages in thread
From: Marc Kleine-Budde @ 2022-01-07 19:31 UTC (permalink / raw)
  To: linux-can; +Cc: Dario Binacchi, Marc Kleine-Budde

Most flexcan IP cores support 2 RX modes:
- FIFO
- mailbox

The names for these modes were chosen to reflect the name of the
rx-offload mode they are using.

The name of the RX modes should better reflect their difference with
regards the flexcan IP core. So this patch renames the various
occurrences of OFF_FIFO to RX_FIFO and OFF_TIMESTAMP to RX_MAILBOX:

| FLEXCAN_TX_MB_RESERVED_OFF_FIFO -> FLEXCAN_TX_MB_RESERVED_RX_FIFO
| FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP -> FLEXCAN_TX_MB_RESERVED_RX_MAILBOX
| FLEXCAN_QUIRK_USE_OFF_TIMESTAMP -> FLEXCAN_QUIRK_USE_RX_MAILBOX

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/flexcan/flexcan-core.c | 48 +++++++++++++-------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index 26bf0a0a72f1..ba52e70d6a16 100644
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -173,9 +173,9 @@
 
 /* FLEXCAN interrupt flag register (IFLAG) bits */
 /* Errata ERR005829 step7: Reserve first valid MB */
-#define FLEXCAN_TX_MB_RESERVED_OFF_FIFO		8
-#define FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP	0
-#define FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST	(FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP + 1)
+#define FLEXCAN_TX_MB_RESERVED_RX_FIFO	8
+#define FLEXCAN_TX_MB_RESERVED_RX_MAILBOX	0
+#define FLEXCAN_RX_MB_RX_MAILBOX_FIRST	(FLEXCAN_TX_MB_RESERVED_RX_MAILBOX + 1)
 #define FLEXCAN_IFLAG_MB(x)		BIT_ULL(x)
 #define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW	BIT(7)
 #define FLEXCAN_IFLAG_RX_FIFO_WARN	BIT(6)
@@ -234,8 +234,8 @@
 #define FLEXCAN_QUIRK_ENABLE_EACEN_RRS  BIT(3)
 /* Disable non-correctable errors interrupt and freeze mode */
 #define FLEXCAN_QUIRK_DISABLE_MECR BIT(4)
-/* Use timestamp based offloading */
-#define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP BIT(5)
+/* Use mailboxes (not FIFO) for RX path */
+#define FLEXCAN_QUIRK_USE_RX_MAILBOX BIT(5)
 /* No interrupt for error passive */
 #define FLEXCAN_QUIRK_BROKEN_PERR_STATE BIT(6)
 /* default to BE register access */
@@ -406,38 +406,38 @@ static const struct flexcan_devtype_data fsl_imx28_devtype_data = {
 
 static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
-		FLEXCAN_QUIRK_USE_OFF_TIMESTAMP | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
+		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
 		FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR,
 };
 
 static const struct flexcan_devtype_data fsl_imx8qm_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
-		FLEXCAN_QUIRK_USE_OFF_TIMESTAMP | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
+		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
 		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW,
 };
 
 static struct flexcan_devtype_data fsl_imx8mp_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
-		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_OFF_TIMESTAMP |
+		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_RX_MAILBOX |
 		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR |
 		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SUPPORT_ECC,
 };
 
 static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
-		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_OFF_TIMESTAMP |
+		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_RX_MAILBOX |
 		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_SUPPORT_ECC,
 };
 
 static const struct flexcan_devtype_data fsl_ls1021a_r2_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
-		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_USE_OFF_TIMESTAMP,
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_USE_RX_MAILBOX,
 };
 
 static const struct flexcan_devtype_data fsl_lx2160a_r1_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
-		FLEXCAN_QUIRK_USE_OFF_TIMESTAMP | FLEXCAN_QUIRK_SUPPORT_FD |
+		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_SUPPORT_FD |
 		FLEXCAN_QUIRK_SUPPORT_ECC,
 };
 
@@ -1022,7 +1022,7 @@ static struct sk_buff *flexcan_mailbox_read(struct can_rx_offload *offload,
 
 	mb = flexcan_get_mb(priv, n);
 
-	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX) {
 		u32 code;
 
 		do {
@@ -1087,7 +1087,7 @@ static struct sk_buff *flexcan_mailbox_read(struct can_rx_offload *offload,
 	}
 
  mark_as_read:
-	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX)
 		flexcan_write64(priv, FLEXCAN_IFLAG_MB(n), &regs->iflag1);
 	else
 		priv->write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
@@ -1113,7 +1113,7 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 	enum can_state last_state = priv->can.state;
 
 	/* reception interrupt */
-	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX) {
 		u64 reg_iflag_rx;
 		int ret;
 
@@ -1429,20 +1429,20 @@ static int flexcan_rx_offload_setup(struct net_device *dev)
 		priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
 				 (sizeof(priv->regs->mb[1]) / priv->mb_size);
 
-	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX)
 		priv->tx_mb_reserved =
-			flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP);
+			flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_RX_MAILBOX);
 	else
 		priv->tx_mb_reserved =
-			flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_OFF_FIFO);
+			flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_RX_FIFO);
 	priv->tx_mb_idx = priv->mb_count - 1;
 	priv->tx_mb = flexcan_get_mb(priv, priv->tx_mb_idx);
 	priv->tx_mask = FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
 
 	priv->offload.mailbox_read = flexcan_mailbox_read;
 
-	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
-		priv->offload.mb_first = FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST;
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX) {
+		priv->offload.mb_first = FLEXCAN_RX_MB_RX_MAILBOX_FIRST;
 		priv->offload.mb_last = priv->mb_count - 2;
 
 		priv->rx_mask = GENMASK_ULL(priv->offload.mb_last,
@@ -1532,10 +1532,10 @@ static int flexcan_chip_start(struct net_device *dev)
 	/* MCR
 	 *
 	 * FIFO:
-	 * - disable for timestamp mode
+	 * - disable for mailbox mode
 	 * - enable for FIFO mode
 	 */
-	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX)
 		reg_mcr &= ~FLEXCAN_MCR_FEN;
 	else
 		reg_mcr |= FLEXCAN_MCR_FEN;
@@ -1631,7 +1631,7 @@ static int flexcan_chip_start(struct net_device *dev)
 		priv->write(reg_fdctrl, &regs->fdctrl);
 	}
 
-	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX) {
 		for (i = priv->offload.mb_first; i <= priv->offload.mb_last; i++) {
 			mb = flexcan_get_mb(priv, i);
 			priv->write(FLEXCAN_MB_CODE_RX_EMPTY,
@@ -1639,7 +1639,7 @@ static int flexcan_chip_start(struct net_device *dev)
 		}
 	} else {
 		/* clear and invalidate unused mailboxes first */
-		for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i < priv->mb_count; i++) {
+		for (i = FLEXCAN_TX_MB_RESERVED_RX_FIFO; i < priv->mb_count; i++) {
 			mb = flexcan_get_mb(priv, i);
 			priv->write(FLEXCAN_MB_CODE_RX_INACTIVE,
 				    &mb->can_ctrl);
@@ -2164,7 +2164,7 @@ static int flexcan_probe(struct platform_device *pdev)
 		return -ENODEV;
 
 	if ((devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_FD) &&
-	    !(devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)) {
+	    !(devtype_data->quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX)) {
 		dev_err(&pdev->dev, "CAN-FD mode doesn't work with FIFO mode!\n");
 		return -EINVAL;
 	}
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v3 4/7] can: flexcan: add more quirks to describe RX path capabilities
  2022-01-07 19:30 [PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime Marc Kleine-Budde
                   ` (2 preceding siblings ...)
  2022-01-07 19:31 ` [PATCH v3 3/7] can: flexcan: rename RX modes Marc Kleine-Budde
@ 2022-01-07 19:31 ` Marc Kleine-Budde
  2022-01-07 19:31 ` [PATCH v3 5/7] can: flexcan: add ethtool support to change rx-rtr setting during runtime Marc Kleine-Budde
                   ` (2 subsequent siblings)
  6 siblings, 0 replies; 10+ messages in thread
From: Marc Kleine-Budde @ 2022-01-07 19:31 UTC (permalink / raw)
  To: linux-can; +Cc: Dario Binacchi, Marc Kleine-Budde

Most flexcan IP cores support 2 RX modes:
- FIFO
- mailbox

Some IP core versions cannot receive CAN RTR messages via mailboxes.
This patch adds quirks to document this.

This information will be used in a later patch to switch from FIFO to
more performant mailbox mode at the expense of losing the ability to
receive RTR messages. This trade off is beneficial in certain use
cases.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/flexcan/flexcan-core.c | 66 +++++++++++++++++++++-----
 1 file changed, 54 insertions(+), 12 deletions(-)

diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index ba52e70d6a16..57cebc415661 100644
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -252,6 +252,12 @@
 #define FLEXCAN_QUIRK_NR_IRQ_3 BIT(12)
 /* Setup 16 mailboxes */
 #define FLEXCAN_QUIRK_NR_MB_16 BIT(13)
+/* Device supports RX via mailboxes */
+#define FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX BIT(14)
+/* Device supports RTR reception via mailboxes */
+#define FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR BIT(15)
+/* Device supports RX via FIFO */
+#define FLEXCAN_QUIRK_SUPPPORT_RX_FIFO BIT(16)
 
 /* Structure of the message buffer */
 struct flexcan_mb {
@@ -386,59 +392,78 @@ struct flexcan_priv {
 
 static const struct flexcan_devtype_data fsl_mcf5441x_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE |
-		FLEXCAN_QUIRK_NR_IRQ_3 | FLEXCAN_QUIRK_NR_MB_16,
+		FLEXCAN_QUIRK_NR_IRQ_3 | FLEXCAN_QUIRK_NR_MB_16 |
+		FLEXCAN_QUIRK_SUPPPORT_RX_FIFO,
 };
 
 static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
 		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
-		FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN,
+		FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_FIFO,
 };
 
 static const struct flexcan_devtype_data fsl_imx25_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
-		FLEXCAN_QUIRK_BROKEN_PERR_STATE,
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_FIFO,
 };
 
 static const struct flexcan_devtype_data fsl_imx28_devtype_data = {
-	.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE,
+	.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_FIFO,
 };
 
 static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
 		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
-		FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR,
+		FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR,
 };
 
 static const struct flexcan_devtype_data fsl_imx8qm_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
 		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
-		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW,
+		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR,
 };
 
 static struct flexcan_devtype_data fsl_imx8mp_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_RX_MAILBOX |
 		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR |
-		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SUPPORT_ECC,
+		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SUPPORT_ECC |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR,
 };
 
 static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_RX_MAILBOX |
-		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_SUPPORT_ECC,
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_SUPPORT_ECC |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR,
 };
 
 static const struct flexcan_devtype_data fsl_ls1021a_r2_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
-		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_USE_RX_MAILBOX,
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_USE_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR,
 };
 
 static const struct flexcan_devtype_data fsl_lx2160a_r1_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
 		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_SUPPORT_FD |
-		FLEXCAN_QUIRK_SUPPORT_ECC,
+		FLEXCAN_QUIRK_SUPPORT_ECC |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR,
 };
 
 static const struct can_bittiming_const flexcan_bittiming_const = {
@@ -2164,8 +2189,25 @@ static int flexcan_probe(struct platform_device *pdev)
 		return -ENODEV;
 
 	if ((devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_FD) &&
-	    !(devtype_data->quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX)) {
-		dev_err(&pdev->dev, "CAN-FD mode doesn't work with FIFO mode!\n");
+	    !((devtype_data->quirks &
+	       (FLEXCAN_QUIRK_USE_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR |
+		FLEXCAN_QUIRK_SUPPPORT_RX_FIFO)) ==
+	      (FLEXCAN_QUIRK_USE_RX_MAILBOX |
+	       FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+	       FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR))) {
+		dev_err(&pdev->dev, "CAN-FD mode doesn't work in RX-FIFO mode!\n");
+		return -EINVAL;
+	}
+
+	if ((devtype_data->quirks &
+	     (FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+	      FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR)) ==
+	    FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR) {
+		dev_err(&pdev->dev,
+			"Quirks (0x%08x) inconsistent: RX_MAILBOX_RX supported but not RX_MAILBOX\n",
+			devtype_data->quirks);
 		return -EINVAL;
 	}
 
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v3 5/7] can: flexcan: add ethtool support to change rx-rtr setting during runtime
  2022-01-07 19:30 [PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime Marc Kleine-Budde
                   ` (3 preceding siblings ...)
  2022-01-07 19:31 ` [PATCH v3 4/7] can: flexcan: add more quirks to describe RX path capabilities Marc Kleine-Budde
@ 2022-01-07 19:31 ` Marc Kleine-Budde
  2022-01-07 19:31 ` [PATCH v3 6/7] docs: networking: device drivers: add can sub-folder Marc Kleine-Budde
  2022-01-07 19:31 ` [PATCH v3 7/7] docs: networking: device drivers: can: add flexcan Marc Kleine-Budde
  6 siblings, 0 replies; 10+ messages in thread
From: Marc Kleine-Budde @ 2022-01-07 19:31 UTC (permalink / raw)
  To: linux-can; +Cc: Dario Binacchi, Marc Kleine-Budde

This patch adds a private flag to the flexcan driver to switch the
"rx-rtr" setting on and off.

"rx-rtr" on  - Receive RTR frames. (default)
               The CAN controller can and will receive RTR frames.

	       On some IP cores the controller cannot receive RTR
	       frames in the more performant "RX mailbox" mode and
	       will use "RX FIFO" mode instead.

"rx-rtr" off - Waive ability to receive RTR frames. (not supported on all IP cores)
               This mode activates the "RX mailbox mode" for better
	       performance, on some IP cores RTR frames cannot be
	       received anymore.

The "RX FIFO" mode uses a FIFO with a depth of 6 CAN frames.
The "RX mailbox" mode uses up to 62 mailboxes.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Co-developed-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/flexcan/Makefile          |   1 +
 drivers/net/can/flexcan/flexcan-core.c    | 102 +-------------
 drivers/net/can/flexcan/flexcan-ethtool.c |  93 ++++++++++++
 drivers/net/can/flexcan/flexcan.h         | 163 ++++++++++++++++++++++
 4 files changed, 260 insertions(+), 99 deletions(-)
 create mode 100644 drivers/net/can/flexcan/flexcan-ethtool.c
 create mode 100644 drivers/net/can/flexcan/flexcan.h

diff --git a/drivers/net/can/flexcan/Makefile b/drivers/net/can/flexcan/Makefile
index 25dd1d12b866..89d5695c902e 100644
--- a/drivers/net/can/flexcan/Makefile
+++ b/drivers/net/can/flexcan/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_CAN_FLEXCAN) += flexcan.o
 
 flexcan-objs :=
 flexcan-objs += flexcan-core.o
+flexcan-objs += flexcan-ethtool.o
diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index 57cebc415661..0bff1884d5cc 100644
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -15,7 +15,6 @@
 #include <linux/can/dev.h>
 #include <linux/can/error.h>
 #include <linux/can/led.h>
-#include <linux/can/rx-offload.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/firmware/imx/sci.h>
@@ -33,6 +32,8 @@
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 
+#include "flexcan.h"
+
 #define DRV_NAME			"flexcan"
 
 /* 8 for RX fifo and 2 error handling */
@@ -206,59 +207,6 @@
 
 #define FLEXCAN_TIMEOUT_US		(250)
 
-/* FLEXCAN hardware feature flags
- *
- * Below is some version info we got:
- *    SOC   Version   IP-Version  Glitch- [TR]WRN_INT IRQ Err Memory err RTR rece-   FD Mode     MB
- *                                Filter? connected?  Passive detection  ption in MB Supported?
- * MCF5441X FlexCAN2  ?               no       yes        no       no       yes           no     16
- *    MX25  FlexCAN2  03.00.00.00     no        no        no       no        no           no     64
- *    MX28  FlexCAN2  03.00.04.00    yes       yes        no       no        no           no     64
- *    MX35  FlexCAN2  03.00.00.00     no        no        no       no        no           no     64
- *    MX53  FlexCAN2  03.00.00.00    yes        no        no       no        no           no     64
- *    MX6s  FlexCAN3  10.00.12.00    yes       yes        no       no       yes           no     64
- *    MX8QM FlexCAN3  03.00.23.00    yes       yes        no       no       yes          yes     64
- *    MX8MP FlexCAN3  03.00.17.01    yes       yes        no      yes       yes          yes     64
- *    VF610 FlexCAN3  ?               no       yes        no      yes       yes?          no     64
- *  LS1021A FlexCAN2  03.00.04.00     no       yes        no       no       yes           no     64
- *  LX2160A FlexCAN3  03.00.23.00     no       yes        no      yes       yes          yes     64
- *
- * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
- */
-
-/* [TR]WRN_INT not connected */
-#define FLEXCAN_QUIRK_BROKEN_WERR_STATE BIT(1)
- /* Disable RX FIFO Global mask */
-#define FLEXCAN_QUIRK_DISABLE_RXFG BIT(2)
-/* Enable EACEN and RRS bit in ctrl2 */
-#define FLEXCAN_QUIRK_ENABLE_EACEN_RRS  BIT(3)
-/* Disable non-correctable errors interrupt and freeze mode */
-#define FLEXCAN_QUIRK_DISABLE_MECR BIT(4)
-/* Use mailboxes (not FIFO) for RX path */
-#define FLEXCAN_QUIRK_USE_RX_MAILBOX BIT(5)
-/* No interrupt for error passive */
-#define FLEXCAN_QUIRK_BROKEN_PERR_STATE BIT(6)
-/* default to BE register access */
-#define FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN BIT(7)
-/* Setup stop mode with GPR to support wakeup */
-#define FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR BIT(8)
-/* Support CAN-FD mode */
-#define FLEXCAN_QUIRK_SUPPORT_FD BIT(9)
-/* support memory detection and correction */
-#define FLEXCAN_QUIRK_SUPPORT_ECC BIT(10)
-/* Setup stop mode with SCU firmware to support wakeup */
-#define FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW BIT(11)
-/* Setup 3 separate interrupts, main, boff and err */
-#define FLEXCAN_QUIRK_NR_IRQ_3 BIT(12)
-/* Setup 16 mailboxes */
-#define FLEXCAN_QUIRK_NR_MB_16 BIT(13)
-/* Device supports RX via mailboxes */
-#define FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX BIT(14)
-/* Device supports RTR reception via mailboxes */
-#define FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR BIT(15)
-/* Device supports RX via FIFO */
-#define FLEXCAN_QUIRK_SUPPPORT_RX_FIFO BIT(16)
-
 /* Structure of the message buffer */
 struct flexcan_mb {
 	u32 can_ctrl;
@@ -345,51 +293,6 @@ struct flexcan_regs {
 
 static_assert(sizeof(struct flexcan_regs) ==  0x4 * 18 + 0xfb8);
 
-struct flexcan_devtype_data {
-	u32 quirks;		/* quirks needed for different IP cores */
-};
-
-struct flexcan_stop_mode {
-	struct regmap *gpr;
-	u8 req_gpr;
-	u8 req_bit;
-};
-
-struct flexcan_priv {
-	struct can_priv can;
-	struct can_rx_offload offload;
-	struct device *dev;
-
-	struct flexcan_regs __iomem *regs;
-	struct flexcan_mb __iomem *tx_mb;
-	struct flexcan_mb __iomem *tx_mb_reserved;
-	u8 tx_mb_idx;
-	u8 mb_count;
-	u8 mb_size;
-	u8 clk_src;	/* clock source of CAN Protocol Engine */
-	u8 scu_idx;
-
-	u64 rx_mask;
-	u64 tx_mask;
-	u32 reg_ctrl_default;
-
-	struct clk *clk_ipg;
-	struct clk *clk_per;
-	struct flexcan_devtype_data devtype_data;
-	struct regulator *reg_xceiver;
-	struct flexcan_stop_mode stm;
-
-	int irq_boff;
-	int irq_err;
-
-	/* IPC handle when setup stop mode by System Controller firmware(scfw) */
-	struct imx_sc_ipc *sc_ipc_handle;
-
-	/* Read and Write APIs */
-	u32 (*read)(void __iomem *addr);
-	void (*write)(u32 val, void __iomem *addr);
-};
-
 static const struct flexcan_devtype_data fsl_mcf5441x_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE |
 		FLEXCAN_QUIRK_NR_IRQ_3 | FLEXCAN_QUIRK_NR_MB_16 |
@@ -2219,6 +2122,7 @@ static int flexcan_probe(struct platform_device *pdev)
 	SET_NETDEV_DEV(dev, &pdev->dev);
 
 	dev->netdev_ops = &flexcan_netdev_ops;
+	flexcan_set_ethtool_ops(dev);
 	dev->irq = irq;
 	dev->flags |= IFF_ECHO;
 
diff --git a/drivers/net/can/flexcan/flexcan-ethtool.c b/drivers/net/can/flexcan/flexcan-ethtool.c
new file mode 100644
index 000000000000..5bb45653e1ac
--- /dev/null
+++ b/drivers/net/can/flexcan/flexcan-ethtool.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (c) 2022 Amarula Solutions, Dario Binacchi <dario.binacchi@amarulasolutions.com>
+ * Copyright (c) 2022 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+ *
+ */
+
+#include <linux/can/dev.h>
+#include <linux/ethtool.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/platform_device.h>
+
+#include "flexcan.h"
+
+static const char flexcan_priv_flags_strings[][ETH_GSTRING_LEN] = {
+#define FLEXCAN_PRIV_FLAGS_RX_RTR BIT(0)
+	"rx-rtr",
+};
+
+static void
+flexcan_get_strings(struct net_device *ndev, u32 stringset, u8 *data)
+{
+	switch (stringset) {
+	case ETH_SS_PRIV_FLAGS:
+		memcpy(data, flexcan_priv_flags_strings,
+		       sizeof(flexcan_priv_flags_strings));
+	}
+}
+
+static int flexcan_get_sset_count(struct net_device *netdev, int sset)
+{
+	switch (sset) {
+	case ETH_SS_PRIV_FLAGS:
+		return ARRAY_SIZE(flexcan_priv_flags_strings);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static u32 flexcan_get_priv_flags(struct net_device *ndev)
+{
+	const struct flexcan_priv *priv = netdev_priv(ndev);
+	u32 priv_flags = 0;
+
+	if (flexcan_active_rx_rtr(priv))
+		priv_flags |= FLEXCAN_PRIV_FLAGS_RX_RTR;
+
+	return priv_flags;
+}
+
+static int flexcan_set_priv_flags(struct net_device *ndev, u32 priv_flags)
+{
+	struct flexcan_priv *priv = netdev_priv(ndev);
+	u32 quirks = priv->devtype_data.quirks;
+
+	if (priv_flags & FLEXCAN_PRIV_FLAGS_RX_RTR) {
+		if (flexcan_supports_rx_mailbox_rtr(priv))
+			quirks |= FLEXCAN_QUIRK_USE_RX_MAILBOX;
+		else if (flexcan_supports_rx_fifo(priv))
+			quirks &= ~FLEXCAN_QUIRK_USE_RX_MAILBOX;
+		else
+			quirks |= FLEXCAN_QUIRK_USE_RX_MAILBOX;
+	} else {
+		if (flexcan_supports_rx_mailbox(priv))
+			quirks |= FLEXCAN_QUIRK_USE_RX_MAILBOX;
+		else
+			quirks &= ~FLEXCAN_QUIRK_USE_RX_MAILBOX;
+	}
+
+	if (quirks != priv->devtype_data.quirks && netif_running(ndev))
+		return -EBUSY;
+
+	priv->devtype_data.quirks = quirks;
+
+	if (!(priv_flags & FLEXCAN_PRIV_FLAGS_RX_RTR) &&
+	    !flexcan_active_rx_rtr(priv))
+		netdev_info(ndev,
+			    "Activating RX mailbox mode, cannot receive RTR frames.\n");
+
+	return 0;
+}
+
+static const struct ethtool_ops flexcan_ethtool_ops = {
+	.get_sset_count = flexcan_get_sset_count,
+	.get_strings = flexcan_get_strings,
+	.get_priv_flags = flexcan_get_priv_flags,
+	.set_priv_flags = flexcan_set_priv_flags,
+};
+
+void flexcan_set_ethtool_ops(struct net_device *netdev)
+{
+	netdev->ethtool_ops = &flexcan_ethtool_ops;
+}
diff --git a/drivers/net/can/flexcan/flexcan.h b/drivers/net/can/flexcan/flexcan.h
new file mode 100644
index 000000000000..fccdff8b1f0f
--- /dev/null
+++ b/drivers/net/can/flexcan/flexcan.h
@@ -0,0 +1,163 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * flexcan.c - FLEXCAN CAN controller driver
+ *
+ * Copyright (c) 2005-2006 Varma Electronics Oy
+ * Copyright (c) 2009 Sascha Hauer, Pengutronix
+ * Copyright (c) 2010-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+ * Copyright (c) 2014 David Jander, Protonic Holland
+ * Copyright (C) 2022 Amarula Solutions, Dario Binacchi <dario.binacchi@amarulasolutions.com>
+ *
+ * Based on code originally by Andrey Volkov <avolkov@varma-el.com>
+ *
+ */
+
+#ifndef _FLEXCAN_H
+#define _FLEXCAN_H
+
+#include <linux/can/rx-offload.h>
+
+/* FLEXCAN hardware feature flags
+ *
+ * Below is some version info we got:
+ *    SOC   Version   IP-Version  Glitch- [TR]WRN_INT IRQ Err Memory err RTR rece-   FD Mode     MB
+ *                                Filter? connected?  Passive detection  ption in MB Supported?
+ * MCF5441X FlexCAN2  ?               no       yes        no       no       yes           no     16
+ *    MX25  FlexCAN2  03.00.00.00     no        no        no       no        no           no     64
+ *    MX28  FlexCAN2  03.00.04.00    yes       yes        no       no        no           no     64
+ *    MX35  FlexCAN2  03.00.00.00     no        no        no       no        no           no     64
+ *    MX53  FlexCAN2  03.00.00.00    yes        no        no       no        no           no     64
+ *    MX6s  FlexCAN3  10.00.12.00    yes       yes        no       no       yes           no     64
+ *    MX8QM FlexCAN3  03.00.23.00    yes       yes        no       no       yes          yes     64
+ *    MX8MP FlexCAN3  03.00.17.01    yes       yes        no      yes       yes          yes     64
+ *    VF610 FlexCAN3  ?               no       yes        no      yes       yes?          no     64
+ *  LS1021A FlexCAN2  03.00.04.00     no       yes        no       no       yes           no     64
+ *  LX2160A FlexCAN3  03.00.23.00     no       yes        no      yes       yes          yes     64
+ *
+ * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
+ */
+
+/* [TR]WRN_INT not connected */
+#define FLEXCAN_QUIRK_BROKEN_WERR_STATE BIT(1)
+ /* Disable RX FIFO Global mask */
+#define FLEXCAN_QUIRK_DISABLE_RXFG BIT(2)
+/* Enable EACEN and RRS bit in ctrl2 */
+#define FLEXCAN_QUIRK_ENABLE_EACEN_RRS  BIT(3)
+/* Disable non-correctable errors interrupt and freeze mode */
+#define FLEXCAN_QUIRK_DISABLE_MECR BIT(4)
+/* Use mailboxes (not FIFO) for RX path */
+#define FLEXCAN_QUIRK_USE_RX_MAILBOX BIT(5)
+/* No interrupt for error passive */
+#define FLEXCAN_QUIRK_BROKEN_PERR_STATE BIT(6)
+/* default to BE register access */
+#define FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN BIT(7)
+/* Setup stop mode with GPR to support wakeup */
+#define FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR BIT(8)
+/* Support CAN-FD mode */
+#define FLEXCAN_QUIRK_SUPPORT_FD BIT(9)
+/* support memory detection and correction */
+#define FLEXCAN_QUIRK_SUPPORT_ECC BIT(10)
+/* Setup stop mode with SCU firmware to support wakeup */
+#define FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW BIT(11)
+/* Setup 3 separate interrupts, main, boff and err */
+#define FLEXCAN_QUIRK_NR_IRQ_3 BIT(12)
+/* Setup 16 mailboxes */
+#define FLEXCAN_QUIRK_NR_MB_16 BIT(13)
+/* Device supports RX via mailboxes */
+#define FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX BIT(14)
+/* Device supports RTR reception via mailboxes */
+#define FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR BIT(15)
+/* Device supports RX via FIFO */
+#define FLEXCAN_QUIRK_SUPPPORT_RX_FIFO BIT(16)
+
+struct flexcan_devtype_data {
+	u32 quirks;		/* quirks needed for different IP cores */
+};
+
+struct flexcan_stop_mode {
+	struct regmap *gpr;
+	u8 req_gpr;
+	u8 req_bit;
+};
+
+struct flexcan_priv {
+	struct can_priv can;
+	struct can_rx_offload offload;
+	struct device *dev;
+
+	struct flexcan_regs __iomem *regs;
+	struct flexcan_mb __iomem *tx_mb;
+	struct flexcan_mb __iomem *tx_mb_reserved;
+	u8 tx_mb_idx;
+	u8 mb_count;
+	u8 mb_size;
+	u8 clk_src;	/* clock source of CAN Protocol Engine */
+	u8 scu_idx;
+
+	u64 rx_mask;
+	u64 tx_mask;
+	u32 reg_ctrl_default;
+
+	struct clk *clk_ipg;
+	struct clk *clk_per;
+	struct flexcan_devtype_data devtype_data;
+	struct regulator *reg_xceiver;
+	struct flexcan_stop_mode stm;
+
+	int irq_boff;
+	int irq_err;
+
+	/* IPC handle when setup stop mode by System Controller firmware(scfw) */
+	struct imx_sc_ipc *sc_ipc_handle;
+
+	/* Read and Write APIs */
+	u32 (*read)(void __iomem *addr);
+	void (*write)(u32 val, void __iomem *addr);
+};
+
+void flexcan_set_ethtool_ops(struct net_device *dev);
+
+static inline bool
+flexcan_supports_rx_mailbox(const struct flexcan_priv *priv)
+{
+	const u32 quirks = priv->devtype_data.quirks;
+
+	return quirks & FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX;
+}
+
+static inline bool
+flexcan_supports_rx_mailbox_rtr(const struct flexcan_priv *priv)
+{
+	const u32 quirks = priv->devtype_data.quirks;
+
+	return (quirks & (FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+			  FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR)) ==
+		(FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX |
+		 FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR);
+}
+
+static inline bool
+flexcan_supports_rx_fifo(const struct flexcan_priv *priv)
+{
+	const u32 quirks = priv->devtype_data.quirks;
+
+	return quirks & FLEXCAN_QUIRK_SUPPPORT_RX_FIFO;
+}
+
+static inline bool
+flexcan_active_rx_rtr(const struct flexcan_priv *priv)
+{
+	const u32 quirks = priv->devtype_data.quirks;
+
+	if (quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX) {
+		if (quirks & FLEXCAN_QUIRK_SUPPPORT_RX_MAILBOX_RTR)
+			return true;
+	} else {
+		/*  RX-FIFO is always RTR capable */
+		return true;
+	}
+
+	return false;
+}
+
+
+#endif /* _FLEXCAN_H */
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v3 6/7] docs: networking: device drivers: add can sub-folder
  2022-01-07 19:30 [PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime Marc Kleine-Budde
                   ` (4 preceding siblings ...)
  2022-01-07 19:31 ` [PATCH v3 5/7] can: flexcan: add ethtool support to change rx-rtr setting during runtime Marc Kleine-Budde
@ 2022-01-07 19:31 ` Marc Kleine-Budde
  2022-01-07 19:31 ` [PATCH v3 7/7] docs: networking: device drivers: can: add flexcan Marc Kleine-Budde
  6 siblings, 0 replies; 10+ messages in thread
From: Marc Kleine-Budde @ 2022-01-07 19:31 UTC (permalink / raw)
  To: linux-can; +Cc: Dario Binacchi, Marc Kleine-Budde

From: Dario Binacchi <dario.binacchi@amarulasolutions.com>

Add the container for CAN drivers documentation.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 .../networking/device_drivers/can/index.rst    | 18 ++++++++++++++++++
 .../networking/device_drivers/index.rst        |  1 +
 2 files changed, 19 insertions(+)
 create mode 100644 Documentation/networking/device_drivers/can/index.rst

diff --git a/Documentation/networking/device_drivers/can/index.rst b/Documentation/networking/device_drivers/can/index.rst
new file mode 100644
index 000000000000..218276818968
--- /dev/null
+++ b/Documentation/networking/device_drivers/can/index.rst
@@ -0,0 +1,18 @@
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
+Controller Area Network (CAN) Device Drivers
+============================================
+
+Device drivers for CAN devices.
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+.. only::  subproject and html
+
+   Indices
+   =======
+
+   * :ref:`genindex`
diff --git a/Documentation/networking/device_drivers/index.rst b/Documentation/networking/device_drivers/index.rst
index 3a5a1d46e77e..5f5cfdb2a300 100644
--- a/Documentation/networking/device_drivers/index.rst
+++ b/Documentation/networking/device_drivers/index.rst
@@ -11,6 +11,7 @@ Contents:
    appletalk/index
    atm/index
    cable/index
+   can/index
    cellular/index
    ethernet/index
    fddi/index
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v3 7/7] docs: networking: device drivers: can: add flexcan
  2022-01-07 19:30 [PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime Marc Kleine-Budde
                   ` (5 preceding siblings ...)
  2022-01-07 19:31 ` [PATCH v3 6/7] docs: networking: device drivers: add can sub-folder Marc Kleine-Budde
@ 2022-01-07 19:31 ` Marc Kleine-Budde
  2022-01-08 13:12   ` Dario Binacchi
  6 siblings, 1 reply; 10+ messages in thread
From: Marc Kleine-Budde @ 2022-01-07 19:31 UTC (permalink / raw)
  To: linux-can; +Cc: Dario Binacchi, Marc Kleine-Budde

From: Dario Binacchi <dario.binacchi@amarulasolutions.com>

Add initial documentation for Flexcan driver.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 .../device_drivers/can/freescale/flexcan.rst  | 54 +++++++++++++++++++
 .../networking/device_drivers/can/index.rst   |  2 +
 2 files changed, 56 insertions(+)
 create mode 100644 Documentation/networking/device_drivers/can/freescale/flexcan.rst

diff --git a/Documentation/networking/device_drivers/can/freescale/flexcan.rst b/Documentation/networking/device_drivers/can/freescale/flexcan.rst
new file mode 100644
index 000000000000..8cc0359a8588
--- /dev/null
+++ b/Documentation/networking/device_drivers/can/freescale/flexcan.rst
@@ -0,0 +1,54 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+=============================
+Flexcan CAN Controller driver
+=============================
+
+Authors: Marc Kleine-Budde <mkl@pengutronix.de>,
+Dario Binacchi <dario.binacchi@amarula.solutions.com>
+
+On/off RTR frames reception
+===========================
+
+For most flexcan IP cores the driver supports 2 RX modes:
+
+- FIFO
+- mailbox
+
+The older flexcan cores (integrated into the i.MX25, i.MX28, i.MX35
+and i.MX53 SOCs) only reception of RTR frames if the controller is
+configured for RX-FIFO mode.
+
+The RX FIFO mode uses a hardware FIFO with a depth of 6 CAN frames,
+while the mailbox mode uses a software FIFO with a depth of up to 62
+CAN frames. With the help of the bigger buffer, the mailbox mode
+performs better under high system load situations.
+
+As reception of RTR frames is part of the CAN standard, all flexcan
+core come up in a mode where RTR reception is possible.
+
+With the "rx-rtr" private flag the ability to receive RTR frames can
+be waived at the expense of losing the ability to receive RTR
+messages. This trade off is beneficial in certain use cases.
+
+"rx-rtr" on
+  Receive RTR frames. (default)
+
+  The CAN controller can and will receive RTR frames.
+
+  On some IP cores the controller cannot receive RTR frames in the
+  more performant "RX mailbox" mode and will use "RX FIFO" mode
+  instead.
+
+"rx-rtr" off
+
+  Waive ability to receive RTR frames. (not supported on all IP cores)
+
+  This mode activates the "RX mailbox mode" for better performance, on
+  some IP cores RTR frames cannot be received anymore.
+
+The setting can only be changed if the interface is down::
+
+    ip link set dev can0 down
+    ethtool --set-priv-flags can0 rx-rtr {off|on}
+    ip link set dev can0 up
diff --git a/Documentation/networking/device_drivers/can/index.rst b/Documentation/networking/device_drivers/can/index.rst
index 218276818968..58b6e0ad3030 100644
--- a/Documentation/networking/device_drivers/can/index.rst
+++ b/Documentation/networking/device_drivers/can/index.rst
@@ -10,6 +10,8 @@ Contents:
 .. toctree::
    :maxdepth: 2
 
+   freescale/flexcan
+
 .. only::  subproject and html
 
    Indices
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 10+ messages in thread

* Re: [PATCH v3 7/7] docs: networking: device drivers: can: add flexcan
  2022-01-07 19:31 ` [PATCH v3 7/7] docs: networking: device drivers: can: add flexcan Marc Kleine-Budde
@ 2022-01-08 13:12   ` Dario Binacchi
  2022-01-08 19:51     ` Marc Kleine-Budde
  0 siblings, 1 reply; 10+ messages in thread
From: Dario Binacchi @ 2022-01-08 13:12 UTC (permalink / raw)
  To: Marc Kleine-Budde; +Cc: linux-can

Hi Marc,

On Fri, Jan 7, 2022 at 8:31 PM Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>
> From: Dario Binacchi <dario.binacchi@amarulasolutions.com>
>
> Add initial documentation for Flexcan driver.
>
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> ---
>  .../device_drivers/can/freescale/flexcan.rst  | 54 +++++++++++++++++++
>  .../networking/device_drivers/can/index.rst   |  2 +
>  2 files changed, 56 insertions(+)
>  create mode 100644 Documentation/networking/device_drivers/can/freescale/flexcan.rst
>
> diff --git a/Documentation/networking/device_drivers/can/freescale/flexcan.rst b/Documentation/networking/device_drivers/can/freescale/flexcan.rst
> new file mode 100644
> index 000000000000..8cc0359a8588
> --- /dev/null
> +++ b/Documentation/networking/device_drivers/can/freescale/flexcan.rst
> @@ -0,0 +1,54 @@
> +.. SPDX-License-Identifier: GPL-2.0+
> +
> +=============================
> +Flexcan CAN Controller driver
> +=============================
> +
> +Authors: Marc Kleine-Budde <mkl@pengutronix.de>,
> +Dario Binacchi <dario.binacchi@amarula.solutions.com>
> +
> +On/off RTR frames reception
> +===========================
> +
> +For most flexcan IP cores the driver supports 2 RX modes:
> +
> +- FIFO
> +- mailbox
> +
> +The older flexcan cores (integrated into the i.MX25, i.MX28, i.MX35
> +and i.MX53 SOCs) only reception of RTR frames if the controller is
> +configured for RX-FIFO mode.

only receive RTR frames

> +
> +The RX FIFO mode uses a hardware FIFO with a depth of 6 CAN frames,
> +while the mailbox mode uses a software FIFO with a depth of up to 62
> +CAN frames. With the help of the bigger buffer, the mailbox mode
> +performs better under high system load situations.
> +
> +As reception of RTR frames is part of the CAN standard, all flexcan
> +core come up in a mode where RTR reception is possible.

all flexcan cores

Thanks and regards,
Dario

> +
> +With the "rx-rtr" private flag the ability to receive RTR frames can
> +be waived at the expense of losing the ability to receive RTR
> +messages. This trade off is beneficial in certain use cases.
> +
> +"rx-rtr" on
> +  Receive RTR frames. (default)
> +
> +  The CAN controller can and will receive RTR frames.
> +
> +  On some IP cores the controller cannot receive RTR frames in the
> +  more performant "RX mailbox" mode and will use "RX FIFO" mode
> +  instead.
> +
> +"rx-rtr" off
> +
> +  Waive ability to receive RTR frames. (not supported on all IP cores)
> +
> +  This mode activates the "RX mailbox mode" for better performance, on
> +  some IP cores RTR frames cannot be received anymore.
> +
> +The setting can only be changed if the interface is down::
> +
> +    ip link set dev can0 down
> +    ethtool --set-priv-flags can0 rx-rtr {off|on}
> +    ip link set dev can0 up
> diff --git a/Documentation/networking/device_drivers/can/index.rst b/Documentation/networking/device_drivers/can/index.rst
> index 218276818968..58b6e0ad3030 100644
> --- a/Documentation/networking/device_drivers/can/index.rst
> +++ b/Documentation/networking/device_drivers/can/index.rst
> @@ -10,6 +10,8 @@ Contents:
>  .. toctree::
>     :maxdepth: 2
>
> +   freescale/flexcan
> +
>  .. only::  subproject and html
>
>     Indices
> --
> 2.34.1
>
>


-- 

Dario Binacchi

Embedded Linux Developer

dario.binacchi@amarulasolutions.com

__________________________________


Amarula Solutions SRL

Via Le Canevare 30, 31100 Treviso, Veneto, IT

T. +39 042 243 5310
info@amarulasolutions.com

www.amarulasolutions.com

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v3 7/7] docs: networking: device drivers: can: add flexcan
  2022-01-08 13:12   ` Dario Binacchi
@ 2022-01-08 19:51     ` Marc Kleine-Budde
  0 siblings, 0 replies; 10+ messages in thread
From: Marc Kleine-Budde @ 2022-01-08 19:51 UTC (permalink / raw)
  To: Dario Binacchi; +Cc: linux-can

[-- Attachment #1: Type: text/plain, Size: 1201 bytes --]

On 08.01.2022 14:12:27, Dario Binacchi wrote:
> > +On/off RTR frames reception
> > +===========================
> > +
> > +For most flexcan IP cores the driver supports 2 RX modes:
> > +
> > +- FIFO
> > +- mailbox
> > +
> > +The older flexcan cores (integrated into the i.MX25, i.MX28, i.MX35
> > +and i.MX53 SOCs) only reception of RTR frames if the controller is
> > +configured for RX-FIFO mode.
> 
> only receive RTR frames
> 
> > +
> > +The RX FIFO mode uses a hardware FIFO with a depth of 6 CAN frames,
> > +while the mailbox mode uses a software FIFO with a depth of up to 62
> > +CAN frames. With the help of the bigger buffer, the mailbox mode
> > +performs better under high system load situations.
> > +
> > +As reception of RTR frames is part of the CAN standard, all flexcan
> > +core come up in a mode where RTR reception is possible.
> 
> all flexcan cores

Fixed both.

Thanks,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2022-01-08 19:51 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-07 19:30 [PATCH v2 1/7] can: flexcan: change RX-FIFO feature at runtime Marc Kleine-Budde
2022-01-07 19:30 ` [PATCH v3 1/7] can: flexcan: move driver into separate sub directory Marc Kleine-Budde
2022-01-07 19:31 ` [PATCH v3 2/7] can: flexcan: allow to change quirks at runtime Marc Kleine-Budde
2022-01-07 19:31 ` [PATCH v3 3/7] can: flexcan: rename RX modes Marc Kleine-Budde
2022-01-07 19:31 ` [PATCH v3 4/7] can: flexcan: add more quirks to describe RX path capabilities Marc Kleine-Budde
2022-01-07 19:31 ` [PATCH v3 5/7] can: flexcan: add ethtool support to change rx-rtr setting during runtime Marc Kleine-Budde
2022-01-07 19:31 ` [PATCH v3 6/7] docs: networking: device drivers: add can sub-folder Marc Kleine-Budde
2022-01-07 19:31 ` [PATCH v3 7/7] docs: networking: device drivers: can: add flexcan Marc Kleine-Budde
2022-01-08 13:12   ` Dario Binacchi
2022-01-08 19:51     ` Marc Kleine-Budde

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