]> git.baikalelectronics.ru Git - kernel.git/commitdiff
tsnep: Add free running cycle counter support
authorGerhard Engleder <gerhard@engleder-embedded.com>
Fri, 6 May 2022 20:01:42 +0000 (22:01 +0200)
committerPaolo Abeni <pabeni@redhat.com>
Tue, 10 May 2022 07:48:09 +0000 (09:48 +0200)
The TSN endpoint Ethernet MAC supports a free running counter
additionally to its clock. This free running counter can be read and
hardware timestamps are supported. As the name implies, this counter
cannot be set and its frequency cannot be adjusted.

Add free running cycle counter support based on this free running
counter to physical clock. This also requires hardware time stamps
based on that free running counter.

Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
drivers/net/ethernet/engleder/tsnep_hw.h
drivers/net/ethernet/engleder/tsnep_main.c
drivers/net/ethernet/engleder/tsnep_ptp.c

index 71cc8577d640990af02abe4804c97f70de182ccc..916ceac3ada233c889a58829fb2b93ca60ac0a42 100644 (file)
 #define ECM_RESET_CHANNEL 0x00000100
 #define ECM_RESET_TXRX 0x00010000
 
+/* counter */
+#define ECM_COUNTER_LOW 0x0028
+#define ECM_COUNTER_HIGH 0x002C
+
 /* control and status */
 #define ECM_STATUS 0x0080
 #define ECM_LINK_MODE_OFF 0x01000000
@@ -190,7 +194,8 @@ struct tsnep_tx_desc {
 /* tsnep TX descriptor writeback */
 struct tsnep_tx_desc_wb {
        __le32 properties;
-       __le32 reserved1[3];
+       __le32 reserved1;
+       __le64 counter;
        __le64 timestamp;
        __le32 dma_delay;
        __le32 reserved2;
@@ -221,7 +226,7 @@ struct tsnep_rx_desc_wb {
 
 /* tsnep RX inline meta */
 struct tsnep_rx_inline {
-       __le64 reserved;
+       __le64 counter;
        __le64 timestamp;
 };
 
index 49c93aa38862aaa124d9f9ddef1df7cf96268496..cb069a0af7b92447d245b04f88a492b69679b935 100644 (file)
@@ -470,8 +470,15 @@ static bool tsnep_tx_poll(struct tsnep_tx *tx, int napi_budget)
                    (__le32_to_cpu(entry->desc_wb->properties) &
                     TSNEP_DESC_EXTENDED_WRITEBACK_FLAG)) {
                        struct skb_shared_hwtstamps hwtstamps;
-                       u64 timestamp =
-                               __le64_to_cpu(entry->desc_wb->timestamp);
+                       u64 timestamp;
+
+                       if (skb_shinfo(entry->skb)->tx_flags &
+                           SKBTX_HW_TSTAMP_USE_CYCLES)
+                               timestamp =
+                                       __le64_to_cpu(entry->desc_wb->counter);
+                       else
+                               timestamp =
+                                       __le64_to_cpu(entry->desc_wb->timestamp);
 
                        memset(&hwtstamps, 0, sizeof(hwtstamps));
                        hwtstamps.hwtstamp = ns_to_ktime(timestamp);
@@ -704,11 +711,11 @@ static int tsnep_rx_poll(struct tsnep_rx *rx, struct napi_struct *napi,
                                        skb_hwtstamps(skb);
                                struct tsnep_rx_inline *rx_inline =
                                        (struct tsnep_rx_inline *)skb->data;
-                               u64 timestamp =
-                                       __le64_to_cpu(rx_inline->timestamp);
 
+                               skb_shinfo(skb)->tx_flags |=
+                                       SKBTX_HW_TSTAMP_NETDEV;
                                memset(hwtstamps, 0, sizeof(*hwtstamps));
-                               hwtstamps->hwtstamp = ns_to_ktime(timestamp);
+                               hwtstamps->netdev_data = rx_inline;
                        }
                        skb_pull(skb, TSNEP_RX_INLINE_METADATA_SIZE);
                        skb->protocol = eth_type_trans(skb,
@@ -1010,6 +1017,21 @@ static int tsnep_netdev_set_mac_address(struct net_device *netdev, void *addr)
        return 0;
 }
 
+static ktime_t tsnep_netdev_get_tstamp(struct net_device *netdev,
+                                      const struct skb_shared_hwtstamps *hwtstamps,
+                                      bool cycles)
+{
+       struct tsnep_rx_inline *rx_inline = hwtstamps->netdev_data;
+       u64 timestamp;
+
+       if (cycles)
+               timestamp = __le64_to_cpu(rx_inline->counter);
+       else
+               timestamp = __le64_to_cpu(rx_inline->timestamp);
+
+       return ns_to_ktime(timestamp);
+}
+
 static const struct net_device_ops tsnep_netdev_ops = {
        .ndo_open = tsnep_netdev_open,
        .ndo_stop = tsnep_netdev_close,
@@ -1019,6 +1041,7 @@ static const struct net_device_ops tsnep_netdev_ops = {
 
        .ndo_get_stats64 = tsnep_netdev_get_stats64,
        .ndo_set_mac_address = tsnep_netdev_set_mac_address,
+       .ndo_get_tstamp = tsnep_netdev_get_tstamp,
        .ndo_setup_tc = tsnep_tc_setup,
 };
 
index eaad453d487e11029d2ed3bb6861aa7b1e0aa069..54fbf0126815fe94ec932e56d7487bd8f6f802e7 100644 (file)
@@ -175,6 +175,33 @@ static int tsnep_ptp_settime64(struct ptp_clock_info *ptp,
        return 0;
 }
 
+static int tsnep_ptp_getcyclesx64(struct ptp_clock_info *ptp,
+                                 struct timespec64 *ts,
+                                 struct ptp_system_timestamp *sts)
+{
+       struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
+                                                    ptp_clock_info);
+       u32 high_before;
+       u32 low;
+       u32 high;
+       u64 counter;
+
+       /* read high dword twice to detect overrun */
+       high = ioread32(adapter->addr + ECM_COUNTER_HIGH);
+       do {
+               ptp_read_system_prets(sts);
+               low = ioread32(adapter->addr + ECM_COUNTER_LOW);
+               ptp_read_system_postts(sts);
+               high_before = high;
+               high = ioread32(adapter->addr + ECM_COUNTER_HIGH);
+       } while (high != high_before);
+       counter = (((u64)high) << 32) | ((u64)low);
+
+       *ts = ns_to_timespec64(counter);
+
+       return 0;
+}
+
 int tsnep_ptp_init(struct tsnep_adapter *adapter)
 {
        int retval = 0;
@@ -192,6 +219,7 @@ int tsnep_ptp_init(struct tsnep_adapter *adapter)
        adapter->ptp_clock_info.adjtime = tsnep_ptp_adjtime;
        adapter->ptp_clock_info.gettimex64 = tsnep_ptp_gettimex64;
        adapter->ptp_clock_info.settime64 = tsnep_ptp_settime64;
+       adapter->ptp_clock_info.getcyclesx64 = tsnep_ptp_getcyclesx64;
 
        spin_lock_init(&adapter->ptp_lock);