From 39f10239df751e4ec5190ef851a3e71c052c2539 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Fri, 5 Oct 2018 15:42:59 +0300 Subject: stm class: p_sys-t: Add support for CLOCKSYNC packets This adds support for CLOCKSYNC SyS-T packets, that establish correlation between the transport clock (STP timestamps) and SyS-T timestamps. These packets are sent periodically to allow the decoder to keep both time sources in sync. Signed-off-by: Alexander Shishkin Tested-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/stm/p_sys-t.c | 80 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) (limited to 'drivers/hwtracing') diff --git a/drivers/hwtracing/stm/p_sys-t.c b/drivers/hwtracing/stm/p_sys-t.c index ffeb057b777c..b178a5495b67 100644 --- a/drivers/hwtracing/stm/p_sys-t.c +++ b/drivers/hwtracing/stm/p_sys-t.c @@ -72,15 +72,20 @@ enum sys_t_message_string_subtype { MIPI_SYST_SEVERITY(INFO) | \ MIPI_SYST_OPT_GUID) +#define CLOCK_SYNC_HEADER (MIPI_SYST_TYPES(CLOCK, TRANSPORT_SYNC) | \ + MIPI_SYST_SEVERITY(MAX)) + struct sys_t_policy_node { uuid_t uuid; bool do_len; unsigned long ts_interval; + unsigned long clocksync_interval; }; struct sys_t_output { struct sys_t_policy_node node; unsigned long ts_jiffies; + unsigned long clocksync_jiffies; }; static void sys_t_policy_node_init(void *priv) @@ -191,10 +196,42 @@ sys_t_policy_ts_interval_store(struct config_item *item, const char *page, CONFIGFS_ATTR(sys_t_policy_, ts_interval); +static ssize_t sys_t_policy_clocksync_interval_show(struct config_item *item, + char *page) +{ + struct sys_t_policy_node *pn = to_pdrv_policy_node(item); + + return sprintf(page, "%u\n", jiffies_to_msecs(pn->clocksync_interval)); +} + +static ssize_t +sys_t_policy_clocksync_interval_store(struct config_item *item, + const char *page, size_t count) +{ + struct mutex *mutexp = &item->ci_group->cg_subsys->su_mutex; + struct sys_t_policy_node *pn = to_pdrv_policy_node(item); + unsigned int ms; + int ret; + + mutex_lock(mutexp); + ret = kstrtouint(page, 10, &ms); + mutex_unlock(mutexp); + + if (!ret) { + pn->clocksync_interval = msecs_to_jiffies(ms); + return count; + } + + return ret; +} + +CONFIGFS_ATTR(sys_t_policy_, clocksync_interval); + static struct configfs_attribute *sys_t_policy_attrs[] = { &sys_t_policy_attr_uuid, &sys_t_policy_attr_do_len, &sys_t_policy_attr_ts_interval, + &sys_t_policy_attr_clocksync_interval, NULL, }; @@ -210,6 +247,43 @@ static inline bool sys_t_need_ts(struct sys_t_output *op) return false; } +static bool sys_t_need_clock_sync(struct sys_t_output *op) +{ + if (op->node.clocksync_interval && + time_after(op->clocksync_jiffies + op->node.clocksync_interval, + jiffies)) { + op->clocksync_jiffies = jiffies; + + return true; + } + + return false; +} + +static ssize_t +sys_t_clock_sync(struct stm_data *data, unsigned int m, unsigned int c) +{ + u32 header = CLOCK_SYNC_HEADER; + const unsigned char nil = 0; + u64 payload[2]; /* Clock value and frequency */ + ssize_t sz; + + sz = data->packet(data, m, c, STP_PACKET_DATA, STP_PACKET_TIMESTAMPED, + 4, (u8 *)&header); + if (sz <= 0) + return sz; + + payload[0] = ktime_get_real_ns(); + payload[1] = NSEC_PER_SEC; + sz = stm_data_write(data, m, c, false, &payload, sizeof(payload)); + if (sz <= 0) + return sz; + + data->packet(data, m, c, STP_PACKET_FLAG, 0, 0, &nil); + + return sizeof(header) + sizeof(payload); +} + static ssize_t sys_t_write(struct stm_data *data, struct stm_output *output, unsigned int chan, const char *buf, size_t count) { @@ -224,6 +298,12 @@ static ssize_t sys_t_write(struct stm_data *data, struct stm_output *output, if (!op) return -EINVAL; + if (sys_t_need_clock_sync(op)) { + sz = sys_t_clock_sync(data, m, c); + if (sz <= 0) + return sz; + } + if (op->node.do_len) header |= MIPI_SYST_OPT_LEN; if (sys_t_need_ts(op)) -- cgit