[PATCH v8 3/6] mfd: cros-ec: Increase maximum mkbp event size

From: Neil Armstrong
Date: Wed Jul 04 2018 - 11:09:58 EST


Having a 16 byte mkbp event size makes it possible to send CEC
messages from the EC to the AP directly inside the mkbp event
instead of first doing a notification and then a read.

Signed-off-by: Stefan Adolfsson <sadolfsson@xxxxxxxxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Tested-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
drivers/platform/chrome/cros_ec_proto.c | 40 +++++++++++++++++++++++++--------
include/linux/mfd/cros_ec.h | 2 +-
include/linux/mfd/cros_ec_commands.h | 16 +++++++++++++
3 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 8350ca2..398393a 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -506,10 +506,31 @@ int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
}
EXPORT_SYMBOL(cros_ec_cmd_xfer_status);

+static int get_next_event_xfer(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg,
+ int version, uint32_t size)
+{
+ int ret;
+
+ msg->version = version;
+ msg->command = EC_CMD_GET_NEXT_EVENT;
+ msg->insize = size;
+ msg->outsize = 0;
+
+ ret = cros_ec_cmd_xfer(ec_dev, msg);
+ if (ret > 0) {
+ ec_dev->event_size = ret - 1;
+ memcpy(&ec_dev->event_data, msg->data, ec_dev->event_size);
+ }
+
+ return ret;
+}
+
static int get_next_event(struct cros_ec_device *ec_dev)
{
u8 buffer[sizeof(struct cros_ec_command) + sizeof(ec_dev->event_data)];
struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;
+ static int cmd_version = 1;
int ret;

if (ec_dev->suspended) {
@@ -517,18 +538,19 @@ static int get_next_event(struct cros_ec_device *ec_dev)
return -EHOSTDOWN;
}

- msg->version = 0;
- msg->command = EC_CMD_GET_NEXT_EVENT;
- msg->insize = sizeof(ec_dev->event_data);
- msg->outsize = 0;
+ if (cmd_version == 1) {
+ ret = get_next_event_xfer(ec_dev, msg, cmd_version,
+ sizeof(struct ec_response_get_next_event_v1));
+ if (ret < 0 || msg->result != EC_RES_INVALID_VERSION)
+ return ret;

- ret = cros_ec_cmd_xfer(ec_dev, msg);
- if (ret > 0) {
- ec_dev->event_size = ret - 1;
- memcpy(&ec_dev->event_data, msg->data,
- sizeof(ec_dev->event_data));
+ /* Fallback to version 0 for future send attempts */
+ cmd_version = 0;
}

+ ret = get_next_event_xfer(ec_dev, msg, cmd_version,
+ sizeof(struct ec_response_get_next_event));
+
return ret;
}

diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 32421df..20949dd 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -147,7 +147,7 @@ struct cros_ec_device {
bool mkbp_event_supported;
struct blocking_notifier_head event_notifier;

- struct ec_response_get_next_event event_data;
+ struct ec_response_get_next_event_v1 event_data;
int event_size;
u32 host_event_wake_mask;
};
diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index f2edd99..c4f0caa 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -2093,12 +2093,28 @@ union ec_response_get_next_data {
uint32_t sysrq;
} __packed;

+union ec_response_get_next_data_v1 {
+ uint8_t key_matrix[16];
+ uint32_t host_event;
+ uint32_t buttons;
+ uint32_t switches;
+ uint32_t sysrq;
+ uint32_t cec_events;
+ uint8_t cec_message[16];
+} __packed;
+
struct ec_response_get_next_event {
uint8_t event_type;
/* Followed by event data if any */
union ec_response_get_next_data data;
} __packed;

+struct ec_response_get_next_event_v1 {
+ uint8_t event_type;
+ /* Followed by event data if any */
+ union ec_response_get_next_data_v1 data;
+} __packed;
+
/* Bit indices for buttons and switches.*/
/* Buttons */
#define EC_MKBP_POWER_BUTTON 0
--
2.7.4