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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Marc Kleine-Budde <mkl@pengutronix.de>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 0731/1039] can: flexcan: add more quirks to describe RX path capabilities
Date:   Mon, 24 Jan 2022 19:42:00 +0100
Message-Id: <20220124184149.898031977@linuxfoundation.org>
In-Reply-To: <20220124184125.121143506@linuxfoundation.org>
References: <20220124184125.121143506@linuxfoundation.org>
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From: Marc Kleine-Budde <mkl@pengutronix.de>

[ Upstream commit c5c88591040ee7d84d037328eed9019d3ffab821 ]

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.

Link: https://lore.kernel.org/all/20220107193105.1699523-5-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/can/flexcan.c | 66 ++++++++++++++++++++++++++++++++-------
 1 file changed, 54 insertions(+), 12 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index ba52e70d6a166..57cebc4156616 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.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