From 05a3c420eaa6857cb20afe7e3a3c39ed94a3b2c1 Mon Sep 17 00:00:00 2001 From: Gwendal Grignou Date: Tue, 19 Nov 2019 13:45:46 +0100 Subject: platform/chrome: cros-ec: Record event timestamp in the hard irq To improve sensor timestamp precision, given EC and AP are in different time domains, the AP needs to try to record the exact moment an event was signalled to the AP by the EC as soon as possible after it happens. First thing in the hard irq is the best place for this. Signed-off-by: Gwendal Grignou Acked-by: Jonathan Cameron Acked-by: Lee Jones Signed-off-by: Enric Balletbo i Serra --- drivers/platform/chrome/cros_ec_lpc.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/platform/chrome/cros_ec_lpc.c') diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c index 7d10d909435f..3c77496e164d 100644 --- a/drivers/platform/chrome/cros_ec_lpc.c +++ b/drivers/platform/chrome/cros_ec_lpc.c @@ -313,6 +313,8 @@ static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data) { struct cros_ec_device *ec_dev = data; + ec_dev->last_event_time = cros_ec_get_time_ns(); + if (ec_dev->mkbp_event_supported && cros_ec_get_next_event(ec_dev, NULL) > 0) blocking_notifier_call_chain(&ec_dev->event_notifier, 0, -- cgit From 3300fdd630d4d3d96e3ba9af63a740d3a4e8fc61 Mon Sep 17 00:00:00 2001 From: Enrico Granata Date: Tue, 19 Nov 2019 13:45:46 +0100 Subject: platform/chrome: cros_ec: handle MKBP more events flag The ChromeOS EC has support for signaling to the host that a single IRQ can serve multiple MKBP (Matrix KeyBoard Protocol) events. Doing this serves an optimization purpose, as it minimizes the number of round-trips into the interrupt handling machinery, and it proves beneficial to sensor timestamping as it keeps the desired synchronization of event times between the two processors. This patch adds kernel support for this EC feature, allowing the ec_irq to loop until all events have been served. Signed-off-by: Enrico Granata Signed-off-by: Gwendal Grignou Reviewed-by: Jonathan Cameron Acked-by: Lee Jones Signed-off-by: Enric Balletbo i Serra --- drivers/platform/chrome/cros_ec_lpc.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'drivers/platform/chrome/cros_ec_lpc.c') diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c index 3c77496e164d..dccf479c6625 100644 --- a/drivers/platform/chrome/cros_ec_lpc.c +++ b/drivers/platform/chrome/cros_ec_lpc.c @@ -312,13 +312,20 @@ static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset, static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data) { struct cros_ec_device *ec_dev = data; + bool ec_has_more_events; + int ret; ec_dev->last_event_time = cros_ec_get_time_ns(); - if (ec_dev->mkbp_event_supported && - cros_ec_get_next_event(ec_dev, NULL) > 0) - blocking_notifier_call_chain(&ec_dev->event_notifier, 0, - ec_dev); + if (ec_dev->mkbp_event_supported) + do { + ret = cros_ec_get_next_event(ec_dev, NULL, + &ec_has_more_events); + if (ret > 0) + blocking_notifier_call_chain( + &ec_dev->event_notifier, 0, + ec_dev); + } while (ec_has_more_events); if (value == ACPI_NOTIFY_DEVICE_WAKE) pm_system_wakeup(); -- cgit