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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 <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Alexander Shishkin 2018-10-05 15:42:59 +03:00 committed by Greg Kroah-Hartman
parent d69d5e8311
commit 39f10239df
1 changed files with 80 additions and 0 deletions
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80
drivers/hwtracing/stm/p_sys-t.c
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@ -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))