Currently, received messages are sent from the EC in the cec_message
MKBP event. Since the size of ec_response_get_next_data_v1 is 16 bytes,
which is also the maximum size of a CEC message, there is no space to
add a port parameter. Increasing the size of
ec_response_get_next_data_v1 is an option, but this would increase
EC-kernel traffic for all MKBP event types.
Instead, use an event to notify that data is ready, and add a new read
command to read the data.
For backwards compatibility with old EC firmware, continue to handle
cec_message events as well.
Signed-off-by: Reka Norman <rekanorman@xxxxxxxxxxxx>
---
(no changes since v1)
.../media/cec/platform/cros-ec/cros-ec-cec.c | 59 +++++++++++++++++--
.../linux/platform_data/cros_ec_commands.h | 23 ++++++++
2 files changed, 76 insertions(+), 6 deletions(-)
diff --git a/drivers/media/cec/platform/cros-ec/cros-ec-cec.c b/drivers/media/cec/platform/cros-ec/cros-ec-cec.c
index 18f78b7e034a..6989e63c05be 100644
--- a/drivers/media/cec/platform/cros-ec/cros-ec-cec.c
+++ b/drivers/media/cec/platform/cros-ec/cros-ec-cec.c
@@ -59,19 +59,63 @@ struct cros_ec_cec {
struct cros_ec_cec_port *ports[EC_CEC_MAX_PORTS];
};
+static void cros_ec_cec_received_message(struct cros_ec_cec_port *port,
+ uint8_t *msg, uint8_t len)
+{
+ if (len > CEC_MAX_MSG_SIZE)
+ len = CEC_MAX_MSG_SIZE;
+
+ port->rx_msg.len = len;
+ memcpy(port->rx_msg.msg, msg, len);
+
+ cec_received_msg(port->adap, &port->rx_msg);
+}
+
static void handle_cec_message(struct cros_ec_cec *cros_ec_cec)
{
struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
uint8_t *cec_message = cros_ec->event_data.data.cec_message;
unsigned int len = cros_ec->event_size;
- struct cros_ec_cec_port *port = cros_ec_cec->ports[CEC_PORT];
+ struct cros_ec_cec_port *port;
+ /*
+ * There are two ways of receiving CEC messages:
+ * 1. Old EC firmware which only supports one port sends the data in a
+ * cec_message MKBP event.
+ * 2. New EC firmware which supports multiple ports uses
+ * EC_MKBP_CEC_HAVE_DATA to notify that data is ready and
+ * EC_CMD_CEC_READ_MSG to read it.
+ * Check that the EC only has one CEC port, and then we can assume the
+ * message is from port 0.
+ */
+ if (cros_ec_cec->num_ports != 1) {
+ dev_err(cros_ec->dev,
+ "received cec_message on device with %d ports\n",
+ cros_ec_cec->num_ports);
+ return;
+ }
+ port = cros_ec_cec->ports[0];
- if (len > CEC_MAX_MSG_SIZE)
- len = CEC_MAX_MSG_SIZE;
- port->rx_msg.len = len;
- memcpy(port->rx_msg.msg, cec_message, len);
+ cros_ec_cec_received_message(port, cec_message, len);
+}
- cec_received_msg(port->adap, &port->rx_msg);
+static void cros_ec_cec_read_message(struct cros_ec_cec_port *port)
+{
+ struct cros_ec_device *cros_ec = port->cros_ec_cec->cros_ec;
+ struct ec_params_cec_read params = {
+ .port = port->port_num,
+ };
+ struct ec_response_cec_read response;
+ int ret;
+
+ ret = cros_ec_cmd(cros_ec, 0, EC_CMD_CEC_READ_MSG, ¶ms,
+ sizeof(params), &response, sizeof(response));
+ if (ret < 0) {
+ dev_err(cros_ec->dev,
+ "error reading CEC message on EC: %d\n", ret);
+ return;
+ }
+
+ cros_ec_cec_received_message(port, response.msg, response.msg_len);
}
static void handle_cec_event(struct cros_ec_cec *cros_ec_cec)
@@ -97,6 +141,9 @@ static void handle_cec_event(struct cros_ec_cec *cros_ec_cec)
cec_transmit_attempt_done(port->adap,
CEC_TX_STATUS_MAX_RETRIES |
CEC_TX_STATUS_NACK);
+
+ if (events & EC_MKBP_CEC_HAVE_DATA)
+ cros_ec_cec_read_message(port);
}
static int cros_ec_cec_event(struct notifier_block *nb,
diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index b7e8573a8a49..ad61c7ff0b28 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -4473,6 +4473,27 @@ struct ec_params_cec_write_v1 {
uint8_t msg[MAX_CEC_MSG_LEN];
} __ec_align1;
+/* CEC message read from a CEC bus reported back to the AP */
+#define EC_CMD_CEC_READ_MSG 0x00B9
+
+/**
+ * struct ec_params_cec_read - Read a message from the CEC bus
+ * @port: CEC port to read a message on
+ */
+struct ec_params_cec_read {
+ uint8_t port;
+} __ec_align1;
+
+/**
+ * struct ec_response_cec_read - Message read from the CEC bus
+ * @msg_len: length of msg in bytes
+ * @msg: message content read from the CEC bus
+ */
+struct ec_response_cec_read {
+ uint8_t msg_len;
+ uint8_t msg[MAX_CEC_MSG_LEN];
+} __ec_align1;
+
/* Set various CEC parameters */
#define EC_CMD_CEC_SET 0x00BA
@@ -4529,6 +4550,8 @@ enum mkbp_cec_event {
EC_MKBP_CEC_SEND_OK = BIT(0),
/* Outgoing message was not acknowledged */
EC_MKBP_CEC_SEND_FAILED = BIT(1),
+ /* Incoming message can be read out by AP */
+ EC_MKBP_CEC_HAVE_DATA = BIT(2),
};
/*****************************************************************************/
--
2.42.0.rc2.253.gd59a3bf2b4-goog
