From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jimmy Assarsson <extja@kvaser.com>,
        Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [PATCH 5.15 021/171] can: kvaser_usb: get CAN clock frequency from device
Date:   Mon, 13 Dec 2021 10:28:56 +0100
Message-Id: <20211213092945.790910270@linuxfoundation.org>
In-Reply-To: <20211213092945.091487407@linuxfoundation.org>
References: <20211213092945.091487407@linuxfoundation.org>
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From: Jimmy Assarsson <extja@kvaser.com>

commit fb12797ab1fef480ad8a32a30984844444eeb00d upstream.

The CAN clock frequency is used when calculating the CAN bittiming
parameters. When wrong clock frequency is used, the device may end up
with wrong bittiming parameters, depending on user requested bittiming
parameters.

To avoid this, get the CAN clock frequency from the device. Various
existing Kvaser Leaf products use different CAN clocks.

Fixes: 080f40a6fa28 ("can: kvaser_usb: Add support for Kvaser CAN/USB devices")
Link: https://lore.kernel.org/all/20211208152122.250852-2-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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c |  101 ++++++++++++++++-------
 1 file changed, 73 insertions(+), 28 deletions(-)

--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
@@ -28,10 +28,6 @@
 
 #include "kvaser_usb.h"
 
-/* Forward declaration */
-static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_dev_cfg;
-
-#define CAN_USB_CLOCK			8000000
 #define MAX_USBCAN_NET_DEVICES		2
 
 /* Command header size */
@@ -80,6 +76,12 @@ static const struct kvaser_usb_dev_cfg k
 
 #define CMD_LEAF_LOG_MESSAGE		106
 
+/* Leaf frequency options */
+#define KVASER_USB_LEAF_SWOPTION_FREQ_MASK 0x60
+#define KVASER_USB_LEAF_SWOPTION_FREQ_16_MHZ_CLK 0
+#define KVASER_USB_LEAF_SWOPTION_FREQ_32_MHZ_CLK BIT(5)
+#define KVASER_USB_LEAF_SWOPTION_FREQ_24_MHZ_CLK BIT(6)
+
 /* error factors */
 #define M16C_EF_ACKE			BIT(0)
 #define M16C_EF_CRCE			BIT(1)
@@ -340,6 +342,50 @@ struct kvaser_usb_err_summary {
 	};
 };
 
+static const struct can_bittiming_const kvaser_usb_leaf_bittiming_const = {
+	.name = "kvaser_usb",
+	.tseg1_min = KVASER_USB_TSEG1_MIN,
+	.tseg1_max = KVASER_USB_TSEG1_MAX,
+	.tseg2_min = KVASER_USB_TSEG2_MIN,
+	.tseg2_max = KVASER_USB_TSEG2_MAX,
+	.sjw_max = KVASER_USB_SJW_MAX,
+	.brp_min = KVASER_USB_BRP_MIN,
+	.brp_max = KVASER_USB_BRP_MAX,
+	.brp_inc = KVASER_USB_BRP_INC,
+};
+
+static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_dev_cfg_8mhz = {
+	.clock = {
+		.freq = 8000000,
+	},
+	.timestamp_freq = 1,
+	.bittiming_const = &kvaser_usb_leaf_bittiming_const,
+};
+
+static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_dev_cfg_16mhz = {
+	.clock = {
+		.freq = 16000000,
+	},
+	.timestamp_freq = 1,
+	.bittiming_const = &kvaser_usb_leaf_bittiming_const,
+};
+
+static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_dev_cfg_24mhz = {
+	.clock = {
+		.freq = 24000000,
+	},
+	.timestamp_freq = 1,
+	.bittiming_const = &kvaser_usb_leaf_bittiming_const,
+};
+
+static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_dev_cfg_32mhz = {
+	.clock = {
+		.freq = 32000000,
+	},
+	.timestamp_freq = 1,
+	.bittiming_const = &kvaser_usb_leaf_bittiming_const,
+};
+
 static void *
 kvaser_usb_leaf_frame_to_cmd(const struct kvaser_usb_net_priv *priv,
 			     const struct sk_buff *skb, int *frame_len,
@@ -471,6 +517,27 @@ static int kvaser_usb_leaf_send_simple_c
 	return rc;
 }
 
+static void kvaser_usb_leaf_get_software_info_leaf(struct kvaser_usb *dev,
+						   const struct leaf_cmd_softinfo *softinfo)
+{
+	u32 sw_options = le32_to_cpu(softinfo->sw_options);
+
+	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:
+		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;
+	}
+}
+
 static int kvaser_usb_leaf_get_software_info_inner(struct kvaser_usb *dev)
 {
 	struct kvaser_cmd cmd;
@@ -486,14 +553,13 @@ static int kvaser_usb_leaf_get_software_
 
 	switch (dev->card_data.leaf.family) {
 	case KVASER_LEAF:
-		dev->fw_version = le32_to_cpu(cmd.u.leaf.softinfo.fw_version);
-		dev->max_tx_urbs =
-			le16_to_cpu(cmd.u.leaf.softinfo.max_outstanding_tx);
+		kvaser_usb_leaf_get_software_info_leaf(dev, &cmd.u.leaf.softinfo);
 		break;
 	case KVASER_USBCAN:
 		dev->fw_version = le32_to_cpu(cmd.u.usbcan.softinfo.fw_version);
 		dev->max_tx_urbs =
 			le16_to_cpu(cmd.u.usbcan.softinfo.max_outstanding_tx);
+		dev->cfg = &kvaser_usb_leaf_dev_cfg_8mhz;
 		break;
 	}
 
@@ -1225,24 +1291,11 @@ static int kvaser_usb_leaf_init_card(str
 {
 	struct kvaser_usb_dev_card_data *card_data = &dev->card_data;
 
-	dev->cfg = &kvaser_usb_leaf_dev_cfg;
 	card_data->ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 
 	return 0;
 }
 
-static const struct can_bittiming_const kvaser_usb_leaf_bittiming_const = {
-	.name = "kvaser_usb",
-	.tseg1_min = KVASER_USB_TSEG1_MIN,
-	.tseg1_max = KVASER_USB_TSEG1_MAX,
-	.tseg2_min = KVASER_USB_TSEG2_MIN,
-	.tseg2_max = KVASER_USB_TSEG2_MAX,
-	.sjw_max = KVASER_USB_SJW_MAX,
-	.brp_min = KVASER_USB_BRP_MIN,
-	.brp_max = KVASER_USB_BRP_MAX,
-	.brp_inc = KVASER_USB_BRP_INC,
-};
-
 static int kvaser_usb_leaf_set_bittiming(struct net_device *netdev)
 {
 	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
@@ -1348,11 +1401,3 @@ const struct kvaser_usb_dev_ops kvaser_u
 	.dev_read_bulk_callback = kvaser_usb_leaf_read_bulk_callback,
 	.dev_frame_to_cmd = kvaser_usb_leaf_frame_to_cmd,
 };
-
-static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_dev_cfg = {
-	.clock = {
-		.freq = CAN_USB_CLOCK,
-	},
-	.timestamp_freq = 1,
-	.bittiming_const = &kvaser_usb_leaf_bittiming_const,
-};