[PATCH 4.14 3/4] can: kvaser_usb: fix CAN clock frequency regression

[Jimmy Assarsson <extja@kvaser.com>]

commit e6c80e601053ffdac5709f11ff3ec1e19ed05f7b upstream.

The firmware of M32C based Leaf devices expects bittiming parameters
calculated for 16MHz clock. Since we use the actual clock frequency of
the device, the device may end up with wrong bittiming parameters,
depending on user requested parameters.

This regression affects M32C based Leaf devices with non-16MHz clock.

Fixes: 5967fc906ec0 ("can: kvaser_usb: get CAN clock frequency from device")
Link: https://lore.kernel.org/all/20220603083820.800246-3-extja@kvaser.com
Cc: stable@vger.kernel.org
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/usb/kvaser_usb.c | 53 +++++++++++++++++++++-----------
 1 file changed, 35 insertions(+), 18 deletions(-)

diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index 7564194f4c87..5190897ec6c9 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -71,6 +71,7 @@
 /* Kvaser USB device quirks */
 #define KVASER_USB_QUIRK_HAS_SILENT_MODE	BIT(0)
 #define KVASER_USB_QUIRK_HAS_TXRX_ERRORS	BIT(1)
+#define KVASER_USB_QUIRK_IGNORE_CLK_FREQ	BIT(2)
 
 /* Message header size */
 #define MSG_HEADER_LEN			2
@@ -541,23 +542,30 @@ static const struct kvaser_usb_driver_info kvaser_usb_driver_info_usbcan = {
 };
 
 static const struct kvaser_usb_driver_info kvaser_usb_driver_info_leaf = {
-	.quirks = 0,
+	.quirks = KVASER_USB_QUIRK_IGNORE_CLK_FREQ,
 	.family = KVASER_LEAF,
 };
 
 static const struct kvaser_usb_driver_info kvaser_usb_driver_info_leaf_err = {
-	.quirks = KVASER_USB_QUIRK_HAS_TXRX_ERRORS,
+	.quirks = KVASER_USB_QUIRK_HAS_TXRX_ERRORS |
+		  KVASER_USB_QUIRK_IGNORE_CLK_FREQ,
 	.family = KVASER_LEAF,
 };
 
 static const struct kvaser_usb_driver_info kvaser_usb_driver_info_leaf_err_listen = {
 	.quirks = KVASER_USB_QUIRK_HAS_TXRX_ERRORS |
-		  KVASER_USB_QUIRK_HAS_SILENT_MODE,
+		  KVASER_USB_QUIRK_HAS_SILENT_MODE |
+		  KVASER_USB_QUIRK_IGNORE_CLK_FREQ,
+	.family = KVASER_LEAF,
+};
+
+static const struct kvaser_usb_driver_info kvaser_usb_driver_info_leafimx = {
+	.quirks = 0,
 	.family = KVASER_LEAF,
 };
 
 static const struct usb_device_id kvaser_usb_table[] = {
-	/* Leaf family IDs */
+	/* Leaf M32C USB product IDs */
 	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_DEVEL_PRODUCT_ID),
 		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leaf },
 	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_PRODUCT_ID),
@@ -598,16 +606,18 @@ static const struct usb_device_id kvaser_usb_table[] = {
 		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leaf_err },
 	{ USB_DEVICE(KVASER_VENDOR_ID, USB_CAN_R_PRODUCT_ID),
 		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leaf_err },
+
+	/* Leaf i.MX28 USB product IDs */
 	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_V2_PRODUCT_ID),
-		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leaf },
+		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leafimx },
 	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MINI_PCIE_HS_PRODUCT_ID),
-		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leaf },
+		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leafimx },
 	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LIGHT_HS_V2_OEM_PRODUCT_ID),
-		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leaf },
+		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leafimx },
 	{ USB_DEVICE(KVASER_VENDOR_ID, USB_USBCAN_LIGHT_2HS_PRODUCT_ID),
-		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leaf },
+		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leafimx },
 	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MINI_PCIE_2HS_PRODUCT_ID),
-		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leaf },
+		.driver_info = (kernel_ulong_t)&kvaser_usb_driver_info_leafimx },
 
 	/* USBCANII family IDs */
 	{ USB_DEVICE(KVASER_VENDOR_ID, USB_USBCAN2_PRODUCT_ID),
@@ -724,16 +734,23 @@ static void kvaser_usb_get_software_info_leaf(struct kvaser_usb *dev,
 	dev->fw_version = le32_to_cpu(softinfo->fw_version);
 	dev->max_tx_urbs = le16_to_cpu(softinfo->max_outstanding_tx);
 
-	switch (sw_options & KVASER_USB_LEAF_SWOPTION_FREQ_MASK) {
-	case KVASER_USB_LEAF_SWOPTION_FREQ_16_MHZ_CLK:
+	if (dev->driver_info->quirks & KVASER_USB_QUIRK_IGNORE_CLK_FREQ) {
+		/* Firmware expects bittiming parameters calculated for 16MHz
+		 * clock, regardless of the actual clock
+		 */
 		dev->cfg = &kvaser_usb_leaf_dev_cfg_16mhz;
-		break;
-	case KVASER_USB_LEAF_SWOPTION_FREQ_24_MHZ_CLK:
-		dev->cfg = &kvaser_usb_leaf_dev_cfg_24mhz;
-		break;
-	case KVASER_USB_LEAF_SWOPTION_FREQ_32_MHZ_CLK:
-		dev->cfg = &kvaser_usb_leaf_dev_cfg_32mhz;
-		break;
+	} else {
+		switch (sw_options & KVASER_USB_LEAF_SWOPTION_FREQ_MASK) {
+		case KVASER_USB_LEAF_SWOPTION_FREQ_16_MHZ_CLK:
+			dev->cfg = &kvaser_usb_leaf_dev_cfg_16mhz;
+			break;
+		case KVASER_USB_LEAF_SWOPTION_FREQ_24_MHZ_CLK:
+			dev->cfg = &kvaser_usb_leaf_dev_cfg_24mhz;
+			break;
+		case KVASER_USB_LEAF_SWOPTION_FREQ_32_MHZ_CLK:
+			dev->cfg = &kvaser_usb_leaf_dev_cfg_32mhz;
+			break;
+		}
 	}
 }
 
-- 
2.36.1