[PATCH 0/4] can: fsl,flexcan: add fsl,s32v234-flexcan and imx95 wakeup

[PATCH 0/4] can: fsl,flexcan: add fsl,s32v234-flexcan and imx95 wakeup

[Frank Li]

To: Marc Kleine-Budde <mkl@pengutronix.de>
To: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
To: David S. Miller <davem@davemloft.net>
To: Eric Dumazet <edumazet@google.com>
To: Jakub Kicinski <kuba@kernel.org>
To: Paolo Abeni <pabeni@redhat.com>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Conor Dooley <conor+dt@kernel.org>
Cc: linux-can@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: haibo.chen@nxp.com
Cc: imx@lists.linux.dev
Cc: han.xu@nxp.com

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Chircu-Mare Bogdan-Petru (1):
      can: flexcan: Add S32V234 support to FlexCAN driver

Frank Li (1):
      dt-bindings: can: fsl,flexcan: add compatible string fsl,s32v234-flexcan

Haibo Chen (2):
      bingdings: can: flexcan: move fsl,imx95-flexcan standalone
      can: flexcan: add wakeup support for imx95

 .../devicetree/bindings/net/can/fsl,flexcan.yaml   |  5 +-
 drivers/net/can/flexcan/flexcan-core.c             | 54 ++++++++++++++++++++--
 drivers/net/can/flexcan/flexcan.h                  |  2 +
 3 files changed, 53 insertions(+), 8 deletions(-)
---
base-commit: a4cf44c1ad6471737cf687b1f1644cf33641e738
change-id: 20240709-flexcan-c75cfef2acb9

Best regards,
---
Frank Li <Frank.Li@nxp.com>

[PATCH 1/4] dt-bindings: can: fsl,flexcan: add compatible string fsl,s32v234-flexcan

[Frank Li]

Add compatible string fsl,s32v234-flexcan for s32 chips.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
index f197d9b516bb2..b6c92684c5e29 100644
--- a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
+++ b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
@@ -27,6 +27,7 @@ properties:
           - fsl,vf610-flexcan
           - fsl,ls1021ar2-flexcan
           - fsl,lx2160ar1-flexcan
+          - fsl,s32v234-flexcan
       - items:
           - enum:
               - fsl,imx53-flexcan

-- 
2.34.1

Re: [PATCH 1/4] dt-bindings: can: fsl,flexcan: add compatible string fsl,s32v234-flexcan

[Rob Herring (Arm)]

On Thu, 11 Jul 2024 14:20:00 -0400, Frank Li wrote:
> Add compatible string fsl,s32v234-flexcan for s32 chips.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml | 1 +
>  1 file changed, 1 insertion(+)
> 

Acked-by: Rob Herring (Arm) <robh@kernel.org>

[PATCH 2/4] can: flexcan: Add S32V234 support to FlexCAN driver

[Frank Li]

From: Chircu-Mare Bogdan-Petru <Bogdan.Chircu@freescale.com>

Add flexcan support for S32V234.

Signed-off-by: Chircu-Mare Bogdan-Petru <Bogdan.Chircu@freescale.com>
Signed-off-by: Dan Nica <dan.nica@nxp.com>
Signed-off-by: Stefan-Gabriel Mirea <stefan-gabriel.mirea@nxp.com>
Reviewed-by: Li Yang <leoyang.li@nxp.com>
Reviewed-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/net/can/flexcan/flexcan-core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index 8ea7f2795551b..f6e609c388d55 100644
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -378,6 +378,10 @@ static const struct flexcan_devtype_data fsl_lx2160a_r1_devtype_data = {
 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
 };
 
+static struct flexcan_devtype_data fsl_s32v234_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_DISABLE_MECR,
+};
+
 static const struct can_bittiming_const flexcan_bittiming_const = {
 	.name = DRV_NAME,
 	.tseg1_min = 4,
@@ -2018,6 +2022,7 @@ static const struct of_device_id flexcan_of_match[] = {
 	{ .compatible = "fsl,vf610-flexcan", .data = &fsl_vf610_devtype_data, },
 	{ .compatible = "fsl,ls1021ar2-flexcan", .data = &fsl_ls1021a_r2_devtype_data, },
 	{ .compatible = "fsl,lx2160ar1-flexcan", .data = &fsl_lx2160a_r1_devtype_data, },
+	{ .compatible = "fsl,s32v234-flexcan", .data = &fsl_s32v234_devtype_data, },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, flexcan_of_match);

-- 
2.34.1

[PATCH 3/4] bingdings: can: flexcan: move fsl,imx95-flexcan standalone

[Frank Li]

From: Haibo Chen <haibo.chen@nxp.com>

The flexcan in iMX95 is not compatible with imx93 because wakeup method is
difference. Make fsl,imx95-flexcan not fallback to fsl,imx93-flexcan.

Reviewed-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
index b6c92684c5e29..c08bd78e3367e 100644
--- a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
+++ b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
@@ -17,6 +17,7 @@ properties:
   compatible:
     oneOf:
       - enum:
+          - fsl,imx95-flexcan
           - fsl,imx93-flexcan
           - fsl,imx8qm-flexcan
           - fsl,imx8mp-flexcan
@@ -39,9 +40,6 @@ properties:
               - fsl,imx6ul-flexcan
               - fsl,imx6sx-flexcan
           - const: fsl,imx6q-flexcan
-      - items:
-          - const: fsl,imx95-flexcan
-          - const: fsl,imx93-flexcan
       - items:
           - enum:
               - fsl,ls1028ar1-flexcan

-- 
2.34.1

Re: [PATCH 3/4] bingdings: can: flexcan: move fsl,imx95-flexcan standalone

[Frank Li]

Sorry accidently delete 'dt-' in subject. Will fix in next version.
Frank

On Thu, Jul 11, 2024 at 02:20:02PM -0400, Frank Li wrote:
> From: Haibo Chen <haibo.chen@nxp.com>
> 
> The flexcan in iMX95 is not compatible with imx93 because wakeup method is
> difference. Make fsl,imx95-flexcan not fallback to fsl,imx93-flexcan.
> 
> Reviewed-by: Han Xu <han.xu@nxp.com>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
> index b6c92684c5e29..c08bd78e3367e 100644
> --- a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
> +++ b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
> @@ -17,6 +17,7 @@ properties:
>    compatible:
>      oneOf:
>        - enum:
> +          - fsl,imx95-flexcan
>            - fsl,imx93-flexcan
>            - fsl,imx8qm-flexcan
>            - fsl,imx8mp-flexcan
> @@ -39,9 +40,6 @@ properties:
>                - fsl,imx6ul-flexcan
>                - fsl,imx6sx-flexcan
>            - const: fsl,imx6q-flexcan
> -      - items:
> -          - const: fsl,imx95-flexcan
> -          - const: fsl,imx93-flexcan
>        - items:
>            - enum:
>                - fsl,ls1028ar1-flexcan
> 
> -- 
> 2.34.1
> 

Re: [PATCH 3/4] bingdings: can: flexcan: move fsl,imx95-flexcan standalone

[Rob Herring (Arm)]

On Thu, 11 Jul 2024 14:20:02 -0400, Frank Li wrote:
> From: Haibo Chen <haibo.chen@nxp.com>
> 
> The flexcan in iMX95 is not compatible with imx93 because wakeup method is
> difference. Make fsl,imx95-flexcan not fallback to fsl,imx93-flexcan.
> 
> Reviewed-by: Han Xu <han.xu@nxp.com>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

[PATCH 4/4] can: flexcan: add wakeup support for imx95

[Frank Li]

From: Haibo Chen <haibo.chen@nxp.com>

iMX95 define a bit in GPR that assert/desert IPG_STOP signal to Flex CAN
module. It control flexcan enter STOP mode. Wakeup should work even FlexCAN
is in STOP mode.

Due to iMX95 architecture design, A-Core can't access GPR. Only the system
manager (SM) can config GPR. To support the wakeup feature, follow below
steps:

For suspend:

1) linux suspend, when CAN suspend, do nothing for GPR, and keep CAN
related clock on.
2) In ATF, check whether the CAN need to support wakeup, if yes, send a
request to SM through SCMI protocol.
3) In SM, config the GPR and assert IPG_STOP.
4) A-Core suspend.

For wakeup and resume:

1) A-core wakeup event arrive.
2) In SM, deassert IPG_STOP.
3) Linux resume.

Add a new fsl_imx95_devtype_data and FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI to
reflect this.

Reviewed-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/net/can/flexcan/flexcan-core.c | 49 ++++++++++++++++++++++++++++++----
 drivers/net/can/flexcan/flexcan.h      |  2 ++
 2 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index f6e609c388d55..ad3240e7e6ab4 100644
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -354,6 +354,14 @@ static struct flexcan_devtype_data fsl_imx93_devtype_data = {
 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
 };
 
+static struct flexcan_devtype_data fsl_imx95_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_SCMI |
+		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SUPPORT_ECC |
+		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
+		FLEXCAN_QUIRK_SUPPORT_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 |
@@ -548,6 +556,13 @@ static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
 	} else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR) {
 		regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
 				   1 << priv->stm.req_bit, 1 << priv->stm.req_bit);
+	} else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI) {
+		/* For the SCMI mode, driver do nothing, ATF will send request to
+		 * SM(system manager, M33 core) through SCMI protocol after linux
+		 * suspend. Once SM get this request, it will send IPG_STOP signal
+		 * to Flex_CAN, let CAN in STOP mode.
+		 */
+		return 0;
 	}
 
 	return flexcan_low_power_enter_ack(priv);
@@ -559,7 +574,11 @@ static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv)
 	u32 reg_mcr;
 	int ret;
 
-	/* remove stop request */
+	/* Remove stop request, for FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI,
+	 * do nothing here, because ATF already send request to SM before
+	 * linux resume. Once SM get this request, it will deassert the
+	 * IPG_STOP signal to Flex_CAN.
+	 */
 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
 		ret = flexcan_stop_mode_enable_scfw(priv, false);
 		if (ret < 0)
@@ -1987,6 +2006,9 @@ static int flexcan_setup_stop_mode(struct platform_device *pdev)
 		ret = flexcan_setup_stop_mode_scfw(pdev);
 	else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR)
 		ret = flexcan_setup_stop_mode_gpr(pdev);
+	else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI)
+		/* ATF will handle all STOP_IPG related work */
+		ret = 0;
 	else
 		/* return 0 directly if doesn't support stop mode feature */
 		return 0;
@@ -2013,6 +2035,7 @@ static const struct of_device_id flexcan_of_match[] = {
 	{ .compatible = "fsl,imx8qm-flexcan", .data = &fsl_imx8qm_devtype_data, },
 	{ .compatible = "fsl,imx8mp-flexcan", .data = &fsl_imx8mp_devtype_data, },
 	{ .compatible = "fsl,imx93-flexcan", .data = &fsl_imx93_devtype_data, },
+	{ .compatible = "fsl,imx95-flexcan", .data = &fsl_imx95_devtype_data, },
 	{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
 	{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
 	{ .compatible = "fsl,imx53-flexcan", .data = &fsl_imx25_devtype_data, },
@@ -2311,9 +2334,22 @@ static int __maybe_unused flexcan_noirq_suspend(struct device *device)
 	if (netif_running(dev)) {
 		int err;
 
-		if (device_may_wakeup(device))
+		if (device_may_wakeup(device)) {
 			flexcan_enable_wakeup_irq(priv, true);
 
+			/* For FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI, it need
+			 * ATF to send request to SM through SCMI protocol,
+			 * SM will assert the IPG_STOP signal. But all this
+			 * works need the CAN clocks keep on.
+			 * After the CAN module get the IPG_STOP mode, and
+			 * switch to STOP mode, whether still keep the CAN
+			 * clocks on or gate them off depend on the Hardware
+			 * design.
+			 */
+			if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI)
+				return 0;
+		}
+
 		err = pm_runtime_force_suspend(device);
 		if (err)
 			return err;
@@ -2330,9 +2366,12 @@ static int __maybe_unused flexcan_noirq_resume(struct device *device)
 	if (netif_running(dev)) {
 		int err;
 
-		err = pm_runtime_force_resume(device);
-		if (err)
-			return err;
+		if (!(device_may_wakeup(device) &&
+		      priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI)) {
+			err = pm_runtime_force_resume(device);
+			if (err)
+				return err;
+		}
 
 		if (device_may_wakeup(device))
 			flexcan_enable_wakeup_irq(priv, false);
diff --git a/drivers/net/can/flexcan/flexcan.h b/drivers/net/can/flexcan/flexcan.h
index 025c3417031f4..4933d8c7439e6 100644
--- a/drivers/net/can/flexcan/flexcan.h
+++ b/drivers/net/can/flexcan/flexcan.h
@@ -68,6 +68,8 @@
 #define FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR BIT(15)
 /* Device supports RX via FIFO */
 #define FLEXCAN_QUIRK_SUPPORT_RX_FIFO BIT(16)
+/* Setup stop mode with ATF SCMI protocol to support wakeup */
+#define FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI BIT(17)
 
 struct flexcan_devtype_data {
 	u32 quirks;		/* quirks needed for different IP cores */

-- 
2.34.1

Re: [PATCH 4/4] can: flexcan: add wakeup support for imx95

[Vincent MAILHOL]

Hi,

Thank you for the patch. I am not familiar with the iMX95 quirks, but
to the extent of my knowledge, the patch looks good.

Here are a few nits. Next time, maybe you should run a syntax checker
to catch the easy mistakes in the English grammar.

You can directly add my review tag to the v2:

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

Le ven. 12 juil. 2024 à 03:24, Frank Li <Frank.Li@nxp.com> a écrit :
>
> From: Haibo Chen <haibo.chen@nxp.com>
>
> iMX95 define a bit in GPR that assert/desert IPG_STOP signal to Flex CAN
        ^^^^^^
define -> defines
assert/desert -> desert means to "run away" or "leave behind". Not
sure this is the correct word here. Maybe something like set/unset is
better here? This sentence is worth rephrasing.

> module. It control flexcan enter STOP mode. Wakeup should work even FlexCAN
             ^^^^^^^                                             ^^^^
control -> controls
even -> even if

> is in STOP mode.
>
> Due to iMX95 architecture design, A-Core can't access GPR. Only the system
> manager (SM) can config GPR. To support the wakeup feature, follow below
                   ^^^^^^
config -> configure
>
> For suspend:
>
> 1) linux suspend, when CAN suspend, do nothing for GPR, and keep CAN
> related clock on.
> 2) In ATF, check whether the CAN need to support wakeup, if yes, send a
                                   ^^^^
need -> needs

> request to SM through SCMI protocol.
> 3) In SM, config the GPR and assert IPG_STOP.
> 4) A-Core suspend.
>
> For wakeup and resume:
>
> 1) A-core wakeup event arrive.
> 2) In SM, deassert IPG_STOP.
> 3) Linux resume.

Indent your lists:

  - For suspend:

    1) linux suspend, when CAN suspend, do nothing for GPR, and keep CAN
       related clock on.
    2) In ATF, check whether the CAN need to support wakeup, if yes, send a
       request to SM through SCMI protocol.
    3) In SM, config the GPR and assert IPG_STOP.
    4) A-Core suspend.

  - For wakeup and resume:

    1) A-core wakeup event arrive.
    2) In SM, deassert IPG_STOP.
    3) Linux resume.

> Add a new fsl_imx95_devtype_data and FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI to
> reflect this.
>
> Reviewed-by: Han Xu <han.xu@nxp.com>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/net/can/flexcan/flexcan-core.c | 49 ++++++++++++++++++++++++++++++----
>  drivers/net/can/flexcan/flexcan.h      |  2 ++
>  2 files changed, 46 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
> index f6e609c388d55..ad3240e7e6ab4 100644
> --- a/drivers/net/can/flexcan/flexcan-core.c
> +++ b/drivers/net/can/flexcan/flexcan-core.c
> @@ -354,6 +354,14 @@ static struct flexcan_devtype_data fsl_imx93_devtype_data = {
>                 FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
>  };
>
> +static struct flexcan_devtype_data fsl_imx95_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_SCMI |
> +               FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SUPPORT_ECC |
> +               FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
> +               FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
> +};

Can you declare this as constant?

  static const struct flexcan_devtype_data fsl_imx95_devtype_data = {

>  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 |
> @@ -548,6 +556,13 @@ static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
>         } else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR) {
>                 regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
>                                    1 << priv->stm.req_bit, 1 << priv->stm.req_bit);
> +       } else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI) {
> +               /* For the SCMI mode, driver do nothing, ATF will send request to
> +                * SM(system manager, M33 core) through SCMI protocol after linux
> +                * suspend. Once SM get this request, it will send IPG_STOP signal
> +                * to Flex_CAN, let CAN in STOP mode.
> +                */
> +               return 0;
>         }
>
>         return flexcan_low_power_enter_ack(priv);
> @@ -559,7 +574,11 @@ static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv)
>         u32 reg_mcr;
>         int ret;
>
> -       /* remove stop request */
> +       /* Remove stop request, for FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI,
> +        * do nothing here, because ATF already send request to SM before
> +        * linux resume. Once SM get this request, it will deassert the
> +        * IPG_STOP signal to Flex_CAN.
> +        */
>         if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
>                 ret = flexcan_stop_mode_enable_scfw(priv, false);
>                 if (ret < 0)
> @@ -1987,6 +2006,9 @@ static int flexcan_setup_stop_mode(struct platform_device *pdev)
>                 ret = flexcan_setup_stop_mode_scfw(pdev);
>         else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR)
>                 ret = flexcan_setup_stop_mode_gpr(pdev);
> +       else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI)
> +               /* ATF will handle all STOP_IPG related work */
> +               ret = 0;
>         else
>                 /* return 0 directly if doesn't support stop mode feature */
>                 return 0;
> @@ -2013,6 +2035,7 @@ static const struct of_device_id flexcan_of_match[] = {
>         { .compatible = "fsl,imx8qm-flexcan", .data = &fsl_imx8qm_devtype_data, },
>         { .compatible = "fsl,imx8mp-flexcan", .data = &fsl_imx8mp_devtype_data, },
>         { .compatible = "fsl,imx93-flexcan", .data = &fsl_imx93_devtype_data, },
> +       { .compatible = "fsl,imx95-flexcan", .data = &fsl_imx95_devtype_data, },
>         { .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
>         { .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
>         { .compatible = "fsl,imx53-flexcan", .data = &fsl_imx25_devtype_data, },
> @@ -2311,9 +2334,22 @@ static int __maybe_unused flexcan_noirq_suspend(struct device *device)
>         if (netif_running(dev)) {
>                 int err;
>
> -               if (device_may_wakeup(device))
> +               if (device_may_wakeup(device)) {
>                         flexcan_enable_wakeup_irq(priv, true);
>
> +                       /* For FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI, it need
> +                        * ATF to send request to SM through SCMI protocol,
> +                        * SM will assert the IPG_STOP signal. But all this
> +                        * works need the CAN clocks keep on.
> +                        * After the CAN module get the IPG_STOP mode, and
> +                        * switch to STOP mode, whether still keep the CAN
> +                        * clocks on or gate them off depend on the Hardware
> +                        * design.
> +                        */
> +                       if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI)
> +                               return 0;
> +               }
> +
>                 err = pm_runtime_force_suspend(device);
>                 if (err)
>                         return err;
> @@ -2330,9 +2366,12 @@ static int __maybe_unused flexcan_noirq_resume(struct device *device)
>         if (netif_running(dev)) {
>                 int err;
>
> -               err = pm_runtime_force_resume(device);
> -               if (err)
> -                       return err;
> +               if (!(device_may_wakeup(device) &&
> +                     priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI)) {
> +                       err = pm_runtime_force_resume(device);
> +                       if (err)
> +                               return err;
> +               }
>
>                 if (device_may_wakeup(device))
>                         flexcan_enable_wakeup_irq(priv, false);
> diff --git a/drivers/net/can/flexcan/flexcan.h b/drivers/net/can/flexcan/flexcan.h
> index 025c3417031f4..4933d8c7439e6 100644
> --- a/drivers/net/can/flexcan/flexcan.h
> +++ b/drivers/net/can/flexcan/flexcan.h
> @@ -68,6 +68,8 @@
>  #define FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR BIT(15)
>  /* Device supports RX via FIFO */
>  #define FLEXCAN_QUIRK_SUPPORT_RX_FIFO BIT(16)
> +/* Setup stop mode with ATF SCMI protocol to support wakeup */
> +#define FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI BIT(17)
>
>  struct flexcan_devtype_data {
>         u32 quirks;             /* quirks needed for different IP cores */
>
> --
> 2.34.1
>
>