can: kvaser_usb: get CAN clock frequency from device

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>

diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index 2b994bbf85ca3169139df81c24b54b76093de6db..9742e32d5cd541f963b3bea96b85f855a2f84273 100644 (file)
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -31,7 +31,10 @@
 #define USB_SEND_TIMEOUT               1000 /* msecs */
 #define USB_RECV_TIMEOUT               1000 /* msecs */
 #define RX_BUFFER_SIZE                 3072
-#define CAN_USB_CLOCK                  8000000
+#define KVASER_USB_CAN_CLOCK_8MHZ      8000000
+#define KVASER_USB_CAN_CLOCK_16MHZ     16000000
+#define KVASER_USB_CAN_CLOCK_24MHZ     24000000
+#define KVASER_USB_CAN_CLOCK_32MHZ     32000000
 #define MAX_NET_DEVICES                        3
 #define MAX_USBCAN_NET_DEVICES         2
 
@@ -142,6 +145,12 @@ static inline bool kvaser_is_usbcan(const struct usb_device_id *id)
 #define CMD_LEAF_USB_THROTTLE          77
 #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)
@@ -472,6 +481,8 @@ struct kvaser_usb {
        bool rxinitdone;
        void *rxbuf[MAX_RX_URBS];
        dma_addr_t rxbuf_dma[MAX_RX_URBS];
+
+       struct can_clock clock;
 };
 
 struct kvaser_usb_net_priv {
@@ -652,6 +663,27 @@ static int kvaser_usb_send_simple_msg(const struct kvaser_usb *dev,
        return rc;
 }
 
+static void kvaser_usb_get_software_info_leaf(struct kvaser_usb *dev,
+                                             const struct leaf_msg_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->clock.freq = KVASER_USB_CAN_CLOCK_16MHZ;
+               break;
+       case KVASER_USB_LEAF_SWOPTION_FREQ_24_MHZ_CLK:
+               dev->clock.freq = KVASER_USB_CAN_CLOCK_24MHZ;
+               break;
+       case KVASER_USB_LEAF_SWOPTION_FREQ_32_MHZ_CLK:
+               dev->clock.freq = KVASER_USB_CAN_CLOCK_32MHZ;
+               break;
+       }
+}
+
 static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
 {
        struct kvaser_msg msg;
@@ -667,14 +699,13 @@ static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
 
        switch (dev->family) {
        case KVASER_LEAF:
-               dev->fw_version = le32_to_cpu(msg.u.leaf.softinfo.fw_version);
-               dev->max_tx_urbs =
-                       le16_to_cpu(msg.u.leaf.softinfo.max_outstanding_tx);
+               kvaser_usb_get_software_info_leaf(dev, &msg.u.leaf.softinfo);
                break;
        case KVASER_USBCAN:
                dev->fw_version = le32_to_cpu(msg.u.usbcan.softinfo.fw_version);
                dev->max_tx_urbs =
                        le16_to_cpu(msg.u.usbcan.softinfo.max_outstanding_tx);
+               dev->clock.freq = KVASER_USB_CAN_CLOCK_8MHZ;
                break;
        }
 
@@ -1926,7 +1957,7 @@ static int kvaser_usb_init_one(struct usb_interface *intf,
        kvaser_usb_reset_tx_urb_contexts(priv);
 
        priv->can.state = CAN_STATE_STOPPED;
-       priv->can.clock.freq = CAN_USB_CLOCK;
+       priv->can.clock.freq = dev->clock.freq;
        priv->can.bittiming_const = &kvaser_usb_bittiming_const;
        priv->can.do_set_bittiming = kvaser_usb_set_bittiming;
        priv->can.do_set_mode = kvaser_usb_set_mode;