diff options
Diffstat (limited to 'drivers/net/dsa/hirschmann/hellcreek_hwtstamp.c')
-rw-r--r-- | drivers/net/dsa/hirschmann/hellcreek_hwtstamp.c | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/drivers/net/dsa/hirschmann/hellcreek_hwtstamp.c b/drivers/net/dsa/hirschmann/hellcreek_hwtstamp.c new file mode 100644 index 0000000000..bd7aacc71a --- /dev/null +++ b/drivers/net/dsa/hirschmann/hellcreek_hwtstamp.c @@ -0,0 +1,474 @@ +// SPDX-License-Identifier: (GPL-2.0 OR MIT) +/* + * DSA driver for: + * Hirschmann Hellcreek TSN switch. + * + * Copyright (C) 2019,2020 Hochschule Offenburg + * Copyright (C) 2019,2020 Linutronix GmbH + * Authors: Kamil Alkhouri <kamil.alkhouri@hs-offenburg.de> + * Kurt Kanzenbach <kurt@linutronix.de> + */ + +#include <linux/ptp_classify.h> + +#include "hellcreek.h" +#include "hellcreek_hwtstamp.h" +#include "hellcreek_ptp.h" + +int hellcreek_get_ts_info(struct dsa_switch *ds, int port, + struct ethtool_ts_info *info) +{ + struct hellcreek *hellcreek = ds->priv; + + info->phc_index = hellcreek->ptp_clock ? + ptp_clock_index(hellcreek->ptp_clock) : -1; + info->so_timestamping = SOF_TIMESTAMPING_TX_HARDWARE | + SOF_TIMESTAMPING_RX_HARDWARE | + SOF_TIMESTAMPING_RAW_HARDWARE; + + /* enabled tx timestamping */ + info->tx_types = BIT(HWTSTAMP_TX_ON); + + /* L2 & L4 PTPv2 event rx messages are timestamped */ + info->rx_filters = BIT(HWTSTAMP_FILTER_PTP_V2_EVENT); + + return 0; +} + +/* Enabling/disabling TX and RX HW timestamping for different PTP messages is + * not available in the switch. Thus, this function only serves as a check if + * the user requested what is actually available or not + */ +static int hellcreek_set_hwtstamp_config(struct hellcreek *hellcreek, int port, + struct hwtstamp_config *config) +{ + struct hellcreek_port_hwtstamp *ps = + &hellcreek->ports[port].port_hwtstamp; + bool tx_tstamp_enable = false; + bool rx_tstamp_enable = false; + + /* Interaction with the timestamp hardware is prevented here. It is + * enabled when this config function ends successfully + */ + clear_bit_unlock(HELLCREEK_HWTSTAMP_ENABLED, &ps->state); + + switch (config->tx_type) { + case HWTSTAMP_TX_ON: + tx_tstamp_enable = true; + break; + + /* TX HW timestamping can't be disabled on the switch */ + case HWTSTAMP_TX_OFF: + config->tx_type = HWTSTAMP_TX_ON; + break; + + default: + return -ERANGE; + } + + switch (config->rx_filter) { + /* RX HW timestamping can't be disabled on the switch */ + case HWTSTAMP_FILTER_NONE: + config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT; + break; + + case HWTSTAMP_FILTER_PTP_V2_L4_EVENT: + case HWTSTAMP_FILTER_PTP_V2_L4_SYNC: + case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ: + case HWTSTAMP_FILTER_PTP_V2_L2_EVENT: + case HWTSTAMP_FILTER_PTP_V2_L2_SYNC: + case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ: + case HWTSTAMP_FILTER_PTP_V2_EVENT: + case HWTSTAMP_FILTER_PTP_V2_SYNC: + case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ: + config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT; + rx_tstamp_enable = true; + break; + + /* RX HW timestamping can't be enabled for all messages on the switch */ + case HWTSTAMP_FILTER_ALL: + config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT; + break; + + default: + return -ERANGE; + } + + if (!tx_tstamp_enable) + return -ERANGE; + + if (!rx_tstamp_enable) + return -ERANGE; + + /* If this point is reached, then the requested hwtstamp config is + * compatible with the hwtstamp offered by the switch. Therefore, + * enable the interaction with the HW timestamping + */ + set_bit(HELLCREEK_HWTSTAMP_ENABLED, &ps->state); + + return 0; +} + +int hellcreek_port_hwtstamp_set(struct dsa_switch *ds, int port, + struct ifreq *ifr) +{ + struct hellcreek *hellcreek = ds->priv; + struct hellcreek_port_hwtstamp *ps; + struct hwtstamp_config config; + int err; + + ps = &hellcreek->ports[port].port_hwtstamp; + + if (copy_from_user(&config, ifr->ifr_data, sizeof(config))) + return -EFAULT; + + err = hellcreek_set_hwtstamp_config(hellcreek, port, &config); + if (err) + return err; + + /* Save the chosen configuration to be returned later */ + memcpy(&ps->tstamp_config, &config, sizeof(config)); + + return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ? + -EFAULT : 0; +} + +int hellcreek_port_hwtstamp_get(struct dsa_switch *ds, int port, + struct ifreq *ifr) +{ + struct hellcreek *hellcreek = ds->priv; + struct hellcreek_port_hwtstamp *ps; + struct hwtstamp_config *config; + + ps = &hellcreek->ports[port].port_hwtstamp; + config = &ps->tstamp_config; + + return copy_to_user(ifr->ifr_data, config, sizeof(*config)) ? + -EFAULT : 0; +} + +/* Returns a pointer to the PTP header if the caller should time stamp, or NULL + * if the caller should not. + */ +static struct ptp_header *hellcreek_should_tstamp(struct hellcreek *hellcreek, + int port, struct sk_buff *skb, + unsigned int type) +{ + struct hellcreek_port_hwtstamp *ps = + &hellcreek->ports[port].port_hwtstamp; + struct ptp_header *hdr; + + hdr = ptp_parse_header(skb, type); + if (!hdr) + return NULL; + + if (!test_bit(HELLCREEK_HWTSTAMP_ENABLED, &ps->state)) + return NULL; + + return hdr; +} + +static u64 hellcreek_get_reserved_field(const struct ptp_header *hdr) +{ + return be32_to_cpu(hdr->reserved2); +} + +static void hellcreek_clear_reserved_field(struct ptp_header *hdr) +{ + hdr->reserved2 = 0; +} + +static int hellcreek_ptp_hwtstamp_available(struct hellcreek *hellcreek, + unsigned int ts_reg) +{ + u16 status; + + status = hellcreek_ptp_read(hellcreek, ts_reg); + + if (status & PR_TS_STATUS_TS_LOST) + dev_err(hellcreek->dev, + "Tx time stamp lost! This should never happen!\n"); + + /* If hwtstamp is not available, this means the previous hwtstamp was + * successfully read, and the one we need is not yet available + */ + return (status & PR_TS_STATUS_TS_AVAIL) ? 1 : 0; +} + +/* Get nanoseconds timestamp from timestamping unit */ +static u64 hellcreek_ptp_hwtstamp_read(struct hellcreek *hellcreek, + unsigned int ts_reg) +{ + u16 nsl, nsh; + + nsh = hellcreek_ptp_read(hellcreek, ts_reg); + nsh = hellcreek_ptp_read(hellcreek, ts_reg); + nsh = hellcreek_ptp_read(hellcreek, ts_reg); + nsh = hellcreek_ptp_read(hellcreek, ts_reg); + nsl = hellcreek_ptp_read(hellcreek, ts_reg); + + return (u64)nsl | ((u64)nsh << 16); +} + +static int hellcreek_txtstamp_work(struct hellcreek *hellcreek, + struct hellcreek_port_hwtstamp *ps, int port) +{ + struct skb_shared_hwtstamps shhwtstamps; + unsigned int status_reg, data_reg; + struct sk_buff *tmp_skb; + int ts_status; + u64 ns = 0; + + if (!ps->tx_skb) + return 0; + + switch (port) { + case 2: + status_reg = PR_TS_TX_P1_STATUS_C; + data_reg = PR_TS_TX_P1_DATA_C; + break; + case 3: + status_reg = PR_TS_TX_P2_STATUS_C; + data_reg = PR_TS_TX_P2_DATA_C; + break; + default: + dev_err(hellcreek->dev, "Wrong port for timestamping!\n"); + return 0; + } + + ts_status = hellcreek_ptp_hwtstamp_available(hellcreek, status_reg); + + /* Not available yet? */ + if (ts_status == 0) { + /* Check whether the operation of reading the tx timestamp has + * exceeded its allowed period + */ + if (time_is_before_jiffies(ps->tx_tstamp_start + + TX_TSTAMP_TIMEOUT)) { + dev_err(hellcreek->dev, + "Timeout while waiting for Tx timestamp!\n"); + goto free_and_clear_skb; + } + + /* The timestamp should be available quickly, while getting it + * in high priority. Restart the work + */ + return 1; + } + + mutex_lock(&hellcreek->ptp_lock); + ns = hellcreek_ptp_hwtstamp_read(hellcreek, data_reg); + ns += hellcreek_ptp_gettime_seconds(hellcreek, ns); + mutex_unlock(&hellcreek->ptp_lock); + + /* Now we have the timestamp in nanoseconds, store it in the correct + * structure in order to send it to the user + */ + memset(&shhwtstamps, 0, sizeof(shhwtstamps)); + shhwtstamps.hwtstamp = ns_to_ktime(ns); + + tmp_skb = ps->tx_skb; + ps->tx_skb = NULL; + + /* skb_complete_tx_timestamp() frees up the client to make another + * timestampable transmit. We have to be ready for it by clearing the + * ps->tx_skb "flag" beforehand + */ + clear_bit_unlock(HELLCREEK_HWTSTAMP_TX_IN_PROGRESS, &ps->state); + + /* Deliver a clone of the original outgoing tx_skb with tx hwtstamp */ + skb_complete_tx_timestamp(tmp_skb, &shhwtstamps); + + return 0; + +free_and_clear_skb: + dev_kfree_skb_any(ps->tx_skb); + ps->tx_skb = NULL; + clear_bit_unlock(HELLCREEK_HWTSTAMP_TX_IN_PROGRESS, &ps->state); + + return 0; +} + +static void hellcreek_get_rxts(struct hellcreek *hellcreek, + struct hellcreek_port_hwtstamp *ps, + struct sk_buff *skb, struct sk_buff_head *rxq, + int port) +{ + struct skb_shared_hwtstamps *shwt; + struct sk_buff_head received; + unsigned long flags; + + /* Construct Rx timestamps for all received PTP packets. */ + __skb_queue_head_init(&received); + spin_lock_irqsave(&rxq->lock, flags); + skb_queue_splice_tail_init(rxq, &received); + spin_unlock_irqrestore(&rxq->lock, flags); + + for (; skb; skb = __skb_dequeue(&received)) { + struct ptp_header *hdr; + unsigned int type; + u64 ns; + + /* Get nanoseconds from ptp packet */ + type = SKB_PTP_TYPE(skb); + hdr = ptp_parse_header(skb, type); + ns = hellcreek_get_reserved_field(hdr); + hellcreek_clear_reserved_field(hdr); + + /* Add seconds part */ + mutex_lock(&hellcreek->ptp_lock); + ns += hellcreek_ptp_gettime_seconds(hellcreek, ns); + mutex_unlock(&hellcreek->ptp_lock); + + /* Save time stamp */ + shwt = skb_hwtstamps(skb); + memset(shwt, 0, sizeof(*shwt)); + shwt->hwtstamp = ns_to_ktime(ns); + netif_rx(skb); + } +} + +static void hellcreek_rxtstamp_work(struct hellcreek *hellcreek, + struct hellcreek_port_hwtstamp *ps, + int port) +{ + struct sk_buff *skb; + + skb = skb_dequeue(&ps->rx_queue); + if (skb) + hellcreek_get_rxts(hellcreek, ps, skb, &ps->rx_queue, port); +} + +long hellcreek_hwtstamp_work(struct ptp_clock_info *ptp) +{ + struct hellcreek *hellcreek = ptp_to_hellcreek(ptp); + struct dsa_switch *ds = hellcreek->ds; + int i, restart = 0; + + for (i = 0; i < ds->num_ports; i++) { + struct hellcreek_port_hwtstamp *ps; + + if (!dsa_is_user_port(ds, i)) + continue; + + ps = &hellcreek->ports[i].port_hwtstamp; + + if (test_bit(HELLCREEK_HWTSTAMP_TX_IN_PROGRESS, &ps->state)) + restart |= hellcreek_txtstamp_work(hellcreek, ps, i); + + hellcreek_rxtstamp_work(hellcreek, ps, i); + } + + return restart ? 1 : -1; +} + +void hellcreek_port_txtstamp(struct dsa_switch *ds, int port, + struct sk_buff *skb) +{ + struct hellcreek *hellcreek = ds->priv; + struct hellcreek_port_hwtstamp *ps; + struct ptp_header *hdr; + struct sk_buff *clone; + unsigned int type; + + ps = &hellcreek->ports[port].port_hwtstamp; + + type = ptp_classify_raw(skb); + if (type == PTP_CLASS_NONE) + return; + + /* Make sure the message is a PTP message that needs to be timestamped + * and the interaction with the HW timestamping is enabled. If not, stop + * here + */ + hdr = hellcreek_should_tstamp(hellcreek, port, skb, type); + if (!hdr) + return; + + clone = skb_clone_sk(skb); + if (!clone) + return; + + if (test_and_set_bit_lock(HELLCREEK_HWTSTAMP_TX_IN_PROGRESS, + &ps->state)) { + kfree_skb(clone); + return; + } + + ps->tx_skb = clone; + + /* store the number of ticks occurred since system start-up till this + * moment + */ + ps->tx_tstamp_start = jiffies; + + ptp_schedule_worker(hellcreek->ptp_clock, 0); +} + +bool hellcreek_port_rxtstamp(struct dsa_switch *ds, int port, + struct sk_buff *skb, unsigned int type) +{ + struct hellcreek *hellcreek = ds->priv; + struct hellcreek_port_hwtstamp *ps; + struct ptp_header *hdr; + + ps = &hellcreek->ports[port].port_hwtstamp; + + /* This check only fails if the user did not initialize hardware + * timestamping beforehand. + */ + if (ps->tstamp_config.rx_filter != HWTSTAMP_FILTER_PTP_V2_EVENT) + return false; + + /* Make sure the message is a PTP message that needs to be timestamped + * and the interaction with the HW timestamping is enabled. If not, stop + * here + */ + hdr = hellcreek_should_tstamp(hellcreek, port, skb, type); + if (!hdr) + return false; + + SKB_PTP_TYPE(skb) = type; + + skb_queue_tail(&ps->rx_queue, skb); + + ptp_schedule_worker(hellcreek->ptp_clock, 0); + + return true; +} + +static void hellcreek_hwtstamp_port_setup(struct hellcreek *hellcreek, int port) +{ + struct hellcreek_port_hwtstamp *ps = + &hellcreek->ports[port].port_hwtstamp; + + skb_queue_head_init(&ps->rx_queue); +} + +int hellcreek_hwtstamp_setup(struct hellcreek *hellcreek) +{ + struct dsa_switch *ds = hellcreek->ds; + int i; + + /* Initialize timestamping ports. */ + for (i = 0; i < ds->num_ports; ++i) { + if (!dsa_is_user_port(ds, i)) + continue; + + hellcreek_hwtstamp_port_setup(hellcreek, i); + } + + /* Select the synchronized clock as the source timekeeper for the + * timestamps and enable inline timestamping. + */ + hellcreek_ptp_write(hellcreek, PR_SETTINGS_C_TS_SRC_TK_MASK | + PR_SETTINGS_C_RES3TS, + PR_SETTINGS_C); + + return 0; +} + +void hellcreek_hwtstamp_free(struct hellcreek *hellcreek) +{ + /* Nothing todo */ +} |