In beagleplay beagleconnect setup, the AP is not directly connected to
greybus nodes. The SVC and APBridge tasks are moved to cc1352
coprocessor. This means that there is a need to send cport information
between linux host and cc1352.
In the initial version of the driver (and the reference implementation
gbridge I was using), the greybus header pad bytes were being used.
However, this was a violation of greybus spec.
The following patchset creates a wrapper around greybus message to send
the cport information without using the pad bytes.
---
V3:
- Rebase on char-misc-next
V2: https://lists.linaro.org/archives/list/[email protected]/thread/7YX5I6ZYZTNTAHBH3M3KAMOWXMTAWQNW/
- Add more comments explaining the new greybus hdlc frame payload
- Remove msg len warnings. These checks are also performed by
`greybus_data_rcvd` and thus no need for it here.
V1: https://lists.linaro.org/archives/list/[email protected]/thread/Y3ELHKLKTP5TQZ5LYKCE6GHWMA3PUOTV/
Ayush Singh (1):
greybus: gb-beagleplay: Remove use of pad bytes
drivers/greybus/gb-beagleplay.c | 58 ++++++++++++++++++++++++---------
1 file changed, 43 insertions(+), 15 deletions(-)
base-commit: e909abe885e2f399be7ac0560a010d7429f951e1
--
2.43.0
Make gb-beagleplay greybus spec compliant by moving cport information to
transport layer instead of using `header->pad` bytes.
Greybus HDLC frame now has the following payload:
1. le16 cport
2. gb_operation_msg_hdr msg_header
3. u8 *msg_payload
Fixes: ec558bbfea67 ("greybus: Add BeaglePlay Linux Driver")
Signed-off-by: Ayush Singh <[email protected]>
---
drivers/greybus/gb-beagleplay.c | 58 ++++++++++++++++++++++++---------
1 file changed, 43 insertions(+), 15 deletions(-)
diff --git a/drivers/greybus/gb-beagleplay.c b/drivers/greybus/gb-beagleplay.c
index 43318c1993ba..7d98ae1a8263 100644
--- a/drivers/greybus/gb-beagleplay.c
+++ b/drivers/greybus/gb-beagleplay.c
@@ -85,17 +85,31 @@ struct hdlc_payload {
void *buf;
};
+/**
+ * struct hdlc_greybus_frame - Structure to represent greybus HDLC frame payload
+ *
+ * @cport: cport id
+ * @hdr: greybus operation header
+ * @payload: greybus message payload
+ *
+ * The HDLC payload sent over UART for greybus address has cport preappended to greybus message
+ */
+struct hdlc_greybus_frame {
+ __le16 cport;
+ struct gb_operation_msg_hdr hdr;
+ u8 payload[];
+} __packed;
+
static void hdlc_rx_greybus_frame(struct gb_beagleplay *bg, u8 *buf, u16 len)
{
- u16 cport_id;
- struct gb_operation_msg_hdr *hdr = (struct gb_operation_msg_hdr *)buf;
-
- memcpy(&cport_id, hdr->pad, sizeof(cport_id));
+ struct hdlc_greybus_frame *gb_frame = (struct hdlc_greybus_frame *)buf;
+ u16 cport_id = le16_to_cpu(gb_frame->cport);
+ u16 gb_msg_len = le16_to_cpu(gb_frame->hdr.size);
dev_dbg(&bg->sd->dev, "Greybus Operation %u type %X cport %u status %u received",
- hdr->operation_id, hdr->type, cport_id, hdr->result);
+ gb_frame->hdr.operation_id, gb_frame->hdr.type, cport_id, gb_frame->hdr.result);
- greybus_data_rcvd(bg->gb_hd, cport_id, buf, len);
+ greybus_data_rcvd(bg->gb_hd, cport_id, (u8 *)&gb_frame->hdr, gb_msg_len);
}
static void hdlc_rx_dbg_frame(const struct gb_beagleplay *bg, const char *buf, u16 len)
@@ -336,25 +350,39 @@ static struct serdev_device_ops gb_beagleplay_ops = {
.write_wakeup = gb_tty_wakeup,
};
+/**
+ * gb_message_send() - Send greybus message using HDLC over UART
+ *
+ * @hd: pointer to greybus host device
+ * @cport: AP cport where message originates
+ * @msg: greybus message to send
+ * @mask: gfp mask
+ *
+ * Greybus HDLC frame has the following payload:
+ * 1. le16 cport
+ * 2. gb_operation_msg_hdr msg_header
+ * 3. u8 *msg_payload
+ */
static int gb_message_send(struct gb_host_device *hd, u16 cport, struct gb_message *msg, gfp_t mask)
{
struct gb_beagleplay *bg = dev_get_drvdata(&hd->dev);
- struct hdlc_payload payloads[2];
+ struct hdlc_payload payloads[3];
+ __le16 cport_id = cpu_to_le16(cport);
dev_dbg(&hd->dev, "Sending greybus message with Operation %u, Type: %X on Cport %u",
msg->header->operation_id, msg->header->type, cport);
- if (msg->header->size > RX_HDLC_PAYLOAD)
+ if (le16_to_cpu(msg->header->size) > RX_HDLC_PAYLOAD)
return dev_err_probe(&hd->dev, -E2BIG, "Greybus message too big");
- memcpy(msg->header->pad, &cport, sizeof(cport));
-
- payloads[0].buf = msg->header;
- payloads[0].len = sizeof(*msg->header);
- payloads[1].buf = msg->payload;
- payloads[1].len = msg->payload_size;
+ payloads[0].buf = &cport_id;
+ payloads[0].len = sizeof(cport_id);
+ payloads[1].buf = msg->header;
+ payloads[1].len = sizeof(*msg->header);
+ payloads[2].buf = msg->payload;
+ payloads[2].len = msg->payload_size;
- hdlc_tx_frames(bg, ADDRESS_GREYBUS, 0x03, payloads, 2);
+ hdlc_tx_frames(bg, ADDRESS_GREYBUS, 0x03, payloads, 3);
greybus_message_sent(bg->gb_hd, msg, 0);
return 0;
--
2.43.0