From 45dfa45f52e66f8eee30a64b16550a9c47915044 Mon Sep 17 00:00:00 2001 From: John Whittington Date: Mon, 22 Aug 2022 12:01:10 +0200 Subject: can: gs_usb: add RX and TX hardware timestamp support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add support for hardware timestamps, if the firmware includes it as a feature via the GS_CAN_FEATURE_HW_TIMESTAMP flag. Check for this feature during probe, extend the RX expected length if it is and enable it during open. The struct classic_can_ts and struct canfd_ts are extended to include the µs timestamp following data as defined in the firmware. The timestamp is then captured and set using skb_hwtstamps() on each RX and TX. The frame µs timestamp is provided from a 32 bit 1 MHz timer which rolls over every 4294 seconds, so a cyclecounter, timecounter, and delayed worker are used to convert the timer into a proper ns timestamp - same implementation as commit efd8d98dfb900 ("can: mcp251xfd: add HW timestamp infrastructure"). Hardware timestamps are added to capabilities as commit b1f6b93e678f ("can: mcp251xfd: advertise timestamping capabilities and add ioctl support"). Signed-off-by: John Whittington Link: https://github.com/candle-usb/candleLight_fw/issues/100 Link: https://lore.kernel.org/all/20220827221548.3291393-3-mkl@pengutronix.de Co-developed-by: Marc Kleine-Budde Signed-off-by: Marc Kleine-Budde --- drivers/net/can/usb/gs_usb.c | 193 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 186 insertions(+), 7 deletions(-) diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c index 532510902f60..cc363f1935ce 100644 --- a/drivers/net/can/usb/gs_usb.c +++ b/drivers/net/can/usb/gs_usb.c @@ -10,12 +10,16 @@ */ #include +#include #include #include #include #include #include +#include +#include #include +#include #include #include @@ -37,6 +41,14 @@ #define GS_USB_ENDPOINT_IN 1 #define GS_USB_ENDPOINT_OUT 2 +/* Timestamp 32 bit timer runs at 1 MHz (1 µs tick). Worker accounts + * for timer overflow (will be after ~71 minutes) + */ +#define GS_USB_TIMESTAMP_TIMER_HZ (1 * HZ_PER_MHZ) +#define GS_USB_TIMESTAMP_WORK_DELAY_SEC 1800 +static_assert(GS_USB_TIMESTAMP_WORK_DELAY_SEC < + CYCLECOUNTER_MASK(32) / GS_USB_TIMESTAMP_TIMER_HZ / 2); + /* Device specific constants */ enum gs_usb_breq { GS_USB_BREQ_HOST_FORMAT = 0, @@ -199,6 +211,11 @@ struct classic_can { u8 data[8]; } __packed; +struct classic_can_ts { + u8 data[8]; + __le32 timestamp_us; +} __packed; + struct classic_can_quirk { u8 data[8]; u8 quirk; @@ -208,6 +225,11 @@ struct canfd { u8 data[64]; } __packed; +struct canfd_ts { + u8 data[64]; + __le32 timestamp_us; +} __packed; + struct canfd_quirk { u8 data[64]; u8 quirk; @@ -224,8 +246,10 @@ struct gs_host_frame { union { DECLARE_FLEX_ARRAY(struct classic_can, classic_can); + DECLARE_FLEX_ARRAY(struct classic_can_ts, classic_can_ts); DECLARE_FLEX_ARRAY(struct classic_can_quirk, classic_can_quirk); DECLARE_FLEX_ARRAY(struct canfd, canfd); + DECLARE_FLEX_ARRAY(struct canfd_ts, canfd_ts); DECLARE_FLEX_ARRAY(struct canfd_quirk, canfd_quirk); }; } __packed; @@ -259,6 +283,11 @@ struct gs_can { struct can_bittiming_const bt_const, data_bt_const; unsigned int channel; /* channel number */ + /* time counter for hardware timestamps */ + struct cyclecounter cc; + struct timecounter tc; + struct delayed_work timestamp; + u32 feature; unsigned int hf_size_tx; @@ -351,6 +380,87 @@ static int gs_cmd_reset(struct gs_can *gsdev) return rc; } +static inline int gs_usb_get_timestamp(const struct gs_can *dev, + u32 *timestamp_p) +{ + __le32 timestamp; + int rc; + + rc = usb_control_msg_recv(interface_to_usbdev(dev->iface), + usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0), + GS_USB_BREQ_TIMESTAMP, + USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE, + dev->channel, 0, + ×tamp, sizeof(timestamp), + USB_CTRL_GET_TIMEOUT, + GFP_KERNEL); + if (rc) + return rc; + + *timestamp_p = le32_to_cpu(timestamp); + + return 0; +} + +static u64 gs_usb_timestamp_read(const struct cyclecounter *cc) +{ + const struct gs_can *dev; + u32 timestamp = 0; + int err; + + dev = container_of(cc, struct gs_can, cc); + err = gs_usb_get_timestamp(dev, ×tamp); + if (err) + netdev_err(dev->netdev, + "Error %d while reading timestamp. HW timestamps may be inaccurate.", + err); + + return timestamp; +} + +static void gs_usb_timestamp_work(struct work_struct *work) +{ + struct delayed_work *delayed_work = to_delayed_work(work); + struct gs_can *dev; + + dev = container_of(delayed_work, struct gs_can, timestamp); + timecounter_read(&dev->tc); + + schedule_delayed_work(&dev->timestamp, + GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ); +} + +static void gs_usb_skb_set_timestamp(const struct gs_can *dev, + struct sk_buff *skb, u32 timestamp) +{ + struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); + u64 ns; + + ns = timecounter_cyc2time(&dev->tc, timestamp); + hwtstamps->hwtstamp = ns_to_ktime(ns); +} + +static void gs_usb_timestamp_init(struct gs_can *dev) +{ + struct cyclecounter *cc = &dev->cc; + + cc->read = gs_usb_timestamp_read; + cc->mask = CYCLECOUNTER_MASK(32); + cc->shift = 32 - bits_per(NSEC_PER_SEC / GS_USB_TIMESTAMP_TIMER_HZ); + cc->mult = clocksource_hz2mult(GS_USB_TIMESTAMP_TIMER_HZ, cc->shift); + + timecounter_init(&dev->tc, &dev->cc, ktime_get_real_ns()); + + INIT_DELAYED_WORK(&dev->timestamp, gs_usb_timestamp_work); + schedule_delayed_work(&dev->timestamp, + GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ); +} + +static void gs_usb_timestamp_stop(struct gs_can *dev) +{ + cancel_delayed_work_sync(&dev->timestamp); +} + static void gs_update_state(struct gs_can *dev, struct can_frame *cf) { struct can_device_stats *can_stats = &dev->can.can_stats; @@ -376,6 +486,24 @@ static void gs_update_state(struct gs_can *dev, struct can_frame *cf) } } +static void gs_usb_set_timestamp(const struct gs_can *dev, struct sk_buff *skb, + const struct gs_host_frame *hf) +{ + u32 timestamp; + + if (!(dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)) + return; + + if (hf->flags & GS_CAN_FLAG_FD) + timestamp = le32_to_cpu(hf->canfd_ts->timestamp_us); + else + timestamp = le32_to_cpu(hf->classic_can_ts->timestamp_us); + + gs_usb_skb_set_timestamp(dev, skb, timestamp); + + return; +} + static void gs_usb_receive_bulk_callback(struct urb *urb) { struct gs_usb *usbcan = urb->context; @@ -443,6 +571,8 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) gs_update_state(dev, cf); } + gs_usb_set_timestamp(dev, skb, hf); + netdev->stats.rx_packets++; netdev->stats.rx_bytes += hf->can_dlc; @@ -465,6 +595,9 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) goto resubmit_urb; } + skb = dev->can.echo_skb[hf->echo_id]; + gs_usb_set_timestamp(dev, skb, hf); + netdev->stats.tx_packets++; netdev->stats.tx_bytes += can_get_echo_skb(netdev, hf->echo_id, NULL); @@ -823,6 +956,10 @@ static int gs_can_open(struct net_device *netdev) if (ctrlmode & CAN_CTRLMODE_3_SAMPLES) flags |= GS_CAN_MODE_TRIPLE_SAMPLE; + /* if hardware supports timestamps, enable it */ + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + flags |= GS_CAN_MODE_HW_TIMESTAMP; + /* finally start device */ dm->mode = cpu_to_le32(GS_CAN_MODE_START); dm->flags = cpu_to_le32(flags); @@ -840,6 +977,10 @@ static int gs_can_open(struct net_device *netdev) kfree(dm); + /* start polling timestamp */ + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + gs_usb_timestamp_init(dev); + dev->can.state = CAN_STATE_ERROR_ACTIVE; parent->active_channels++; @@ -858,6 +999,10 @@ static int gs_can_close(struct net_device *netdev) netif_stop_queue(netdev); + /* stop polling timestamp */ + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + gs_usb_timestamp_stop(dev); + /* Stop polling */ parent->active_channels--; if (!parent->active_channels) { @@ -890,11 +1035,22 @@ static int gs_can_close(struct net_device *netdev) return 0; } +static int gs_can_eth_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd) +{ + const struct gs_can *dev = netdev_priv(netdev); + + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + return can_eth_ioctl_hwts(netdev, ifr, cmd); + + return -EOPNOTSUPP; +} + static const struct net_device_ops gs_usb_netdev_ops = { .ndo_open = gs_can_open, .ndo_stop = gs_can_close, .ndo_start_xmit = gs_can_start_xmit, .ndo_change_mtu = can_change_mtu, + .ndo_eth_ioctl = gs_can_eth_ioctl, }; static int gs_usb_set_identify(struct net_device *netdev, bool do_identify) @@ -944,9 +1100,21 @@ static int gs_usb_set_phys_id(struct net_device *dev, return rc; } +static int gs_usb_get_ts_info(struct net_device *netdev, + struct ethtool_ts_info *info) +{ + struct gs_can *dev = netdev_priv(netdev); + + /* report if device supports HW timestamps */ + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + return can_ethtool_op_get_ts_info_hwts(netdev, info); + + return ethtool_op_get_ts_info(netdev, info); +} + static const struct ethtool_ops gs_usb_ethtool_ops = { .set_phys_id = gs_usb_set_phys_id, - .get_ts_info = ethtool_op_get_ts_info, + .get_ts_info = gs_usb_get_ts_info, }; static struct gs_can *gs_make_candev(unsigned int channel, @@ -1202,15 +1370,13 @@ static int gs_usb_probe(struct usb_interface *intf, } init_usb_anchor(&dev->rx_submitted); - /* default to classic CAN, switch to CAN-FD if at least one of - * our channels support CAN-FD. - */ - dev->hf_size_rx = struct_size(hf, classic_can, 1); usb_set_intfdata(intf, dev); dev->udev = udev; for (i = 0; i < icount; i++) { + unsigned int hf_size_rx = 0; + dev->canch[i] = gs_make_candev(i, intf, dconf); if (IS_ERR_OR_NULL(dev->canch[i])) { /* save error code to return later */ @@ -1228,8 +1394,21 @@ static int gs_usb_probe(struct usb_interface *intf, } dev->canch[i]->parent = dev; - if (dev->canch[i]->can.ctrlmode_supported & CAN_CTRLMODE_FD) - dev->hf_size_rx = struct_size(hf, canfd, 1); + /* set RX packet size based on FD and if hardware + * timestamps are supported. + */ + if (dev->canch[i]->can.ctrlmode_supported & CAN_CTRLMODE_FD) { + if (dev->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + hf_size_rx = struct_size(hf, canfd_ts, 1); + else + hf_size_rx = struct_size(hf, canfd, 1); + } else { + if (dev->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + hf_size_rx = struct_size(hf, classic_can_ts, 1); + else + hf_size_rx = struct_size(hf, classic_can, 1); + } + dev->hf_size_rx = max(dev->hf_size_rx, hf_size_rx); } kfree(dconf); -- cgit v1.2.3