[PATCH v3 0/2] usb: typec: ucsi_glink: Add support UCSI v2

[PATCH v3 0/2] usb: typec: ucsi_glink: Add support UCSI v2

[Anjelique Melendez]

UCSI v2 specification has increased the MSG_IN and MSG_OUT size from
16 bytes to 256 bytes each for the message exchange between OPM and PPM
This makes the total buffer size increase from 48 bytes to 528 bytes.
Update the buffer size to support this increase.

While at it also update the UCSI read/request buffers to be packed.

Changes since v2:
 - Added "usb: typec: ucsi_glink: Update request/response buffers
   to be packed" patch
 - Added length checks
 - Updated version checks to use UCSI_VERSION_2_0 instead of UCSI_VERSION_2_1
 - link: https://lore.kernel.org/all/20250716005224.312155-1-anjelique.melendez@oss.qualcomm.com/
Changes since v1:
 - Defined buf size in terms of other UCSI defines
 - Removed UCSI_BUF_SIZE and used the explicit v1 or v2 buffer size macros
 - Removed Qualcomm copyright
 - link: https://lore.kernel.org/all/20250624222922.2010820-1-anjelique.melendez@oss.qualcomm.com/

Anjelique Melendez (2):
  usb: typec: ucsi_glink: Update request/response buffers to be packed
  usb: typec: ucsi_glink: Increase buffer size to support UCSI v2

 drivers/usb/typec/ucsi/ucsi_glink.c | 93 ++++++++++++++++++++++++-----
 1 file changed, 79 insertions(+), 14 deletions(-)

-- 
2.34.1

[PATCH v3 1/2] usb: typec: ucsi_glink: Update request/response buffers to be packed

[Anjelique Melendez]

Update the ucsi request/response buffers to be packed to ensure there
are no "holes" in memory while we read/write these structs.

Signed-off-by: Anjelique Melendez <anjelique.melendez@oss.qualcomm.com>
---
 drivers/usb/typec/ucsi/ucsi_glink.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c
index 8af79101a2fc..1f9f0d942c1a 100644
--- a/drivers/usb/typec/ucsi/ucsi_glink.c
+++ b/drivers/usb/typec/ucsi/ucsi_glink.c
@@ -30,24 +30,24 @@ struct ucsi_read_buf_req_msg {
 	struct pmic_glink_hdr   hdr;
 };
 
-struct ucsi_read_buf_resp_msg {
+struct __packed ucsi_read_buf_resp_msg {
 	struct pmic_glink_hdr   hdr;
 	u8                      buf[UCSI_BUF_SIZE];
 	u32                     ret_code;
 };
 
-struct ucsi_write_buf_req_msg {
+struct __packed ucsi_write_buf_req_msg {
 	struct pmic_glink_hdr   hdr;
 	u8                      buf[UCSI_BUF_SIZE];
 	u32                     reserved;
 };
 
-struct ucsi_write_buf_resp_msg {
+struct __packed ucsi_write_buf_resp_msg {
 	struct pmic_glink_hdr   hdr;
 	u32                     ret_code;
 };
 
-struct ucsi_notify_ind_msg {
+struct __packed ucsi_notify_ind_msg {
 	struct pmic_glink_hdr   hdr;
 	u32                     notification;
 	u32                     receiver;
-- 
2.34.1

[PATCH v3 2/2] usb: typec: ucsi_glink: Increase buffer size to support UCSI v2

[Anjelique Melendez]

UCSI v2 specification has increased the MSG_IN and MSG_OUT size from
16 bytes to 256 bytes each for the message exchange between OPM and PPM
This makes the total buffer size increase from 48 bytes to 528 bytes.
Update the buffer size to support this increase.

Signed-off-by: Anjelique Melendez <anjelique.melendez@oss.qualcomm.com>
---
 drivers/usb/typec/ucsi/ucsi_glink.c | 85 +++++++++++++++++++++++++----
 1 file changed, 75 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c
index 1f9f0d942c1a..fc12569ec520 100644
--- a/drivers/usb/typec/ucsi/ucsi_glink.c
+++ b/drivers/usb/typec/ucsi/ucsi_glink.c
@@ -16,10 +16,10 @@
 
 #define PMIC_GLINK_MAX_PORTS		3
 
-#define UCSI_BUF_SIZE                   48
+#define UCSI_BUF_V1_SIZE		(UCSI_MESSAGE_OUT + (UCSI_MESSAGE_OUT - UCSI_MESSAGE_IN))
+#define UCSI_BUF_V2_SIZE		(UCSIv2_MESSAGE_OUT + (UCSIv2_MESSAGE_OUT - UCSI_MESSAGE_IN))
 
 #define MSG_TYPE_REQ_RESP               1
-#define UCSI_BUF_SIZE                   48
 
 #define UC_NOTIFY_RECEIVER_UCSI         0x0
 #define UC_UCSI_READ_BUF_REQ            0x11
@@ -32,13 +32,25 @@ struct ucsi_read_buf_req_msg {
 
 struct __packed ucsi_read_buf_resp_msg {
 	struct pmic_glink_hdr   hdr;
-	u8                      buf[UCSI_BUF_SIZE];
+	u8                      buf[UCSI_BUF_V1_SIZE];
+	u32                     ret_code;
+};
+
+struct __packed ucsi_v2_read_buf_resp_msg {
+	struct pmic_glink_hdr   hdr;
+	u8                      buf[UCSI_BUF_V2_SIZE];
 	u32                     ret_code;
 };
 
 struct __packed ucsi_write_buf_req_msg {
 	struct pmic_glink_hdr   hdr;
-	u8                      buf[UCSI_BUF_SIZE];
+	u8                      buf[UCSI_BUF_V1_SIZE];
+	u32                     reserved;
+};
+
+struct __packed ucsi_v2_write_buf_req_msg {
+	struct pmic_glink_hdr   hdr;
+	u8                      buf[UCSI_BUF_V2_SIZE];
 	u32                     reserved;
 };
 
@@ -72,7 +84,7 @@ struct pmic_glink_ucsi {
 	bool ucsi_registered;
 	bool pd_running;
 
-	u8 read_buf[UCSI_BUF_SIZE];
+	u8 read_buf[UCSI_BUF_V2_SIZE];
 };
 
 static int pmic_glink_ucsi_read(struct ucsi *__ucsi, unsigned int offset,
@@ -131,18 +143,34 @@ static int pmic_glink_ucsi_read_message_in(struct ucsi *ucsi, void *val, size_t
 static int pmic_glink_ucsi_locked_write(struct pmic_glink_ucsi *ucsi, unsigned int offset,
 					const void *val, size_t val_len)
 {
-	struct ucsi_write_buf_req_msg req = {};
+	struct ucsi_v2_write_buf_req_msg req = {};
+	size_t len, max_buf_len;
 	unsigned long left;
 	int ret;
 
 	req.hdr.owner = PMIC_GLINK_OWNER_USBC;
 	req.hdr.type = MSG_TYPE_REQ_RESP;
 	req.hdr.opcode = UC_UCSI_WRITE_BUF_REQ;
+
+	if (ucsi->ucsi->version >= UCSI_VERSION_2_0) {
+		max_buf_len = UCSI_BUF_V2_SIZE;
+		len = sizeof(req);
+	} else if (ucsi->ucsi->version) {
+		max_buf_len = UCSI_BUF_V1_SIZE;
+		len = sizeof(struct ucsi_write_buf_req_msg);
+	} else {
+		dev_err(ucsi->dev, "UCSI version not set\n");
+		return -EINVAL;
+	}
+
+	if (offset + val_len > max_buf_len)
+		return -EINVAL;
+
 	memcpy(&req.buf[offset], val, val_len);
 
 	reinit_completion(&ucsi->write_ack);
 
-	ret = pmic_glink_send(ucsi->client, &req, sizeof(req));
+	ret = pmic_glink_send(ucsi->client, &req, len);
 	if (ret < 0) {
 		dev_err(ucsi->dev, "failed to send UCSI write request: %d\n", ret);
 		return ret;
@@ -216,12 +244,49 @@ static const struct ucsi_operations pmic_glink_ucsi_ops = {
 
 static void pmic_glink_ucsi_read_ack(struct pmic_glink_ucsi *ucsi, const void *data, int len)
 {
-	const struct ucsi_read_buf_resp_msg *resp = data;
+	u32 ret_code, buf_len, max_len;
+	u8 *buf;
+
+	if (ucsi->ucsi->version) {
+		if (ucsi->ucsi->version >= UCSI_VERSION_2_0) {
+			max_len = sizeof(struct ucsi_v2_read_buf_resp_msg);
+			buf = ((struct ucsi_v2_read_buf_resp_msg *)data)->buf;
+			buf_len = UCSI_BUF_V2_SIZE;
+		} else {
+			max_len = sizeof(struct ucsi_read_buf_resp_msg);
+			buf = ((struct ucsi_read_buf_resp_msg *)data)->buf;
+			buf_len = UCSI_BUF_V1_SIZE;
+		}
+	} else if (!ucsi->ucsi->version && !ucsi->ucsi_registered) {
+		/*
+		 * If UCSI version is not known yet because device is not registered, choose buffer
+		 * size which best fits incoming data
+		 */
+		if (len > sizeof(struct pmic_glink_hdr) + UCSI_BUF_V2_SIZE) {
+			max_len = sizeof(struct ucsi_v2_read_buf_resp_msg);
+			buf = ((struct ucsi_v2_read_buf_resp_msg *)data)->buf;
+			buf_len = UCSI_BUF_V2_SIZE;
+		} else {
+			max_len = sizeof(struct ucsi_read_buf_resp_msg);
+			buf = ((struct ucsi_read_buf_resp_msg *)data)->buf;
+			buf_len = UCSI_BUF_V1_SIZE;
+		}
+	} else {
+		dev_err(ucsi->dev, "UCSI version not set\n");
+		return;
+	}
 
-	if (resp->ret_code)
+	if (len > max_len)
+		return;
+
+	if (buf_len > len - sizeof(struct pmic_glink_hdr) - sizeof(u32))
+		buf_len = len - sizeof(struct pmic_glink_hdr) - sizeof(u32);
+
+	memcpy(&ret_code, buf + sizeof(struct pmic_glink_hdr) + buf_len, sizeof(u32));
+	if (ret_code)
 		return;
 
-	memcpy(ucsi->read_buf, resp->buf, UCSI_BUF_SIZE);
+	memcpy(ucsi->read_buf, buf, buf_len);
 	complete(&ucsi->read_ack);
 }
 
-- 
2.34.1

Re: [PATCH v3 1/2] usb: typec: ucsi_glink: Update request/response buffers to be packed

[Heikki Krogerus]

On Wed, Aug 27, 2025 at 01:12:40PM -0700, Anjelique Melendez wrote:
> Update the ucsi request/response buffers to be packed to ensure there
> are no "holes" in memory while we read/write these structs.
> 
> Signed-off-by: Anjelique Melendez <anjelique.melendez@oss.qualcomm.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/usb/typec/ucsi/ucsi_glink.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c
> index 8af79101a2fc..1f9f0d942c1a 100644
> --- a/drivers/usb/typec/ucsi/ucsi_glink.c
> +++ b/drivers/usb/typec/ucsi/ucsi_glink.c
> @@ -30,24 +30,24 @@ struct ucsi_read_buf_req_msg {
>  	struct pmic_glink_hdr   hdr;
>  };
>  
> -struct ucsi_read_buf_resp_msg {
> +struct __packed ucsi_read_buf_resp_msg {
>  	struct pmic_glink_hdr   hdr;
>  	u8                      buf[UCSI_BUF_SIZE];
>  	u32                     ret_code;
>  };
>  
> -struct ucsi_write_buf_req_msg {
> +struct __packed ucsi_write_buf_req_msg {
>  	struct pmic_glink_hdr   hdr;
>  	u8                      buf[UCSI_BUF_SIZE];
>  	u32                     reserved;
>  };
>  
> -struct ucsi_write_buf_resp_msg {
> +struct __packed ucsi_write_buf_resp_msg {
>  	struct pmic_glink_hdr   hdr;
>  	u32                     ret_code;
>  };
>  
> -struct ucsi_notify_ind_msg {
> +struct __packed ucsi_notify_ind_msg {
>  	struct pmic_glink_hdr   hdr;
>  	u32                     notification;
>  	u32                     receiver;
> -- 
> 2.34.1

-- 
heikki

Re: [PATCH v3 2/2] usb: typec: ucsi_glink: Increase buffer size to support UCSI v2

[Heikki Krogerus]

On Wed, Aug 27, 2025 at 01:12:41PM -0700, Anjelique Melendez wrote:
> UCSI v2 specification has increased the MSG_IN and MSG_OUT size from
> 16 bytes to 256 bytes each for the message exchange between OPM and PPM
> This makes the total buffer size increase from 48 bytes to 528 bytes.
> Update the buffer size to support this increase.
> 
> Signed-off-by: Anjelique Melendez <anjelique.melendez@oss.qualcomm.com>
> ---
>  drivers/usb/typec/ucsi/ucsi_glink.c | 85 +++++++++++++++++++++++++----
>  1 file changed, 75 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c
> index 1f9f0d942c1a..fc12569ec520 100644
> --- a/drivers/usb/typec/ucsi/ucsi_glink.c
> +++ b/drivers/usb/typec/ucsi/ucsi_glink.c
> @@ -16,10 +16,10 @@
>  
>  #define PMIC_GLINK_MAX_PORTS		3
>  
> -#define UCSI_BUF_SIZE                   48
> +#define UCSI_BUF_V1_SIZE		(UCSI_MESSAGE_OUT + (UCSI_MESSAGE_OUT - UCSI_MESSAGE_IN))
> +#define UCSI_BUF_V2_SIZE		(UCSIv2_MESSAGE_OUT + (UCSIv2_MESSAGE_OUT - UCSI_MESSAGE_IN))
>  
>  #define MSG_TYPE_REQ_RESP               1
> -#define UCSI_BUF_SIZE                   48
>  
>  #define UC_NOTIFY_RECEIVER_UCSI         0x0
>  #define UC_UCSI_READ_BUF_REQ            0x11
> @@ -32,13 +32,25 @@ struct ucsi_read_buf_req_msg {
>  
>  struct __packed ucsi_read_buf_resp_msg {
>  	struct pmic_glink_hdr   hdr;
> -	u8                      buf[UCSI_BUF_SIZE];
> +	u8                      buf[UCSI_BUF_V1_SIZE];
> +	u32                     ret_code;
> +};
> +
> +struct __packed ucsi_v2_read_buf_resp_msg {
> +	struct pmic_glink_hdr   hdr;
> +	u8                      buf[UCSI_BUF_V2_SIZE];
>  	u32                     ret_code;
>  };

Couldn't you just make a union inside that original struct
ucsi_read_buf_resp_msg?

>  struct __packed ucsi_write_buf_req_msg {
>  	struct pmic_glink_hdr   hdr;
> -	u8                      buf[UCSI_BUF_SIZE];
> +	u8                      buf[UCSI_BUF_V1_SIZE];
> +	u32                     reserved;
> +};
> +
> +struct __packed ucsi_v2_write_buf_req_msg {
> +	struct pmic_glink_hdr   hdr;
> +	u8                      buf[UCSI_BUF_V2_SIZE];
>  	u32                     reserved;
>  };

Ditto for the ucsi_write_buf_req_msg.

> @@ -72,7 +84,7 @@ struct pmic_glink_ucsi {
>  	bool ucsi_registered;
>  	bool pd_running;
>  
> -	u8 read_buf[UCSI_BUF_SIZE];
> +	u8 read_buf[UCSI_BUF_V2_SIZE];
>  };
>  
>  static int pmic_glink_ucsi_read(struct ucsi *__ucsi, unsigned int offset,
> @@ -131,18 +143,34 @@ static int pmic_glink_ucsi_read_message_in(struct ucsi *ucsi, void *val, size_t
>  static int pmic_glink_ucsi_locked_write(struct pmic_glink_ucsi *ucsi, unsigned int offset,
>  					const void *val, size_t val_len)
>  {
> -	struct ucsi_write_buf_req_msg req = {};
> +	struct ucsi_v2_write_buf_req_msg req = {};
> +	size_t len, max_buf_len;
>  	unsigned long left;
>  	int ret;
>  
>  	req.hdr.owner = PMIC_GLINK_OWNER_USBC;
>  	req.hdr.type = MSG_TYPE_REQ_RESP;
>  	req.hdr.opcode = UC_UCSI_WRITE_BUF_REQ;
> +
> +	if (ucsi->ucsi->version >= UCSI_VERSION_2_0) {
> +		max_buf_len = UCSI_BUF_V2_SIZE;
> +		len = sizeof(req);
> +	} else if (ucsi->ucsi->version) {
> +		max_buf_len = UCSI_BUF_V1_SIZE;
> +		len = sizeof(struct ucsi_write_buf_req_msg);
> +	} else {
> +		dev_err(ucsi->dev, "UCSI version not set\n");
> +		return -EINVAL;
> +	}
> +
> +	if (offset + val_len > max_buf_len)
> +		return -EINVAL;
> +
>  	memcpy(&req.buf[offset], val, val_len);
>  
>  	reinit_completion(&ucsi->write_ack);
>  
> -	ret = pmic_glink_send(ucsi->client, &req, sizeof(req));
> +	ret = pmic_glink_send(ucsi->client, &req, len);
>  	if (ret < 0) {
>  		dev_err(ucsi->dev, "failed to send UCSI write request: %d\n", ret);
>  		return ret;
> @@ -216,12 +244,49 @@ static const struct ucsi_operations pmic_glink_ucsi_ops = {
>  
>  static void pmic_glink_ucsi_read_ack(struct pmic_glink_ucsi *ucsi, const void *data, int len)
>  {
> -	const struct ucsi_read_buf_resp_msg *resp = data;
> +	u32 ret_code, buf_len, max_len;
> +	u8 *buf;
> +
> +	if (ucsi->ucsi->version) {
> +		if (ucsi->ucsi->version >= UCSI_VERSION_2_0) {
> +			max_len = sizeof(struct ucsi_v2_read_buf_resp_msg);
> +			buf = ((struct ucsi_v2_read_buf_resp_msg *)data)->buf;
> +			buf_len = UCSI_BUF_V2_SIZE;
> +		} else {
> +			max_len = sizeof(struct ucsi_read_buf_resp_msg);
> +			buf = ((struct ucsi_read_buf_resp_msg *)data)->buf;
> +			buf_len = UCSI_BUF_V1_SIZE;
> +		}
> +	} else if (!ucsi->ucsi->version && !ucsi->ucsi_registered) {

ucsi->ucsi->version will never be set in this else condition,
so no need to check it, no?

> +		/*
> +		 * If UCSI version is not known yet because device is not registered, choose buffer
> +		 * size which best fits incoming data
> +		 */
> +		if (len > sizeof(struct pmic_glink_hdr) + UCSI_BUF_V2_SIZE) {
> +			max_len = sizeof(struct ucsi_v2_read_buf_resp_msg);
> +			buf = ((struct ucsi_v2_read_buf_resp_msg *)data)->buf;
> +			buf_len = UCSI_BUF_V2_SIZE;
> +		} else {
> +			max_len = sizeof(struct ucsi_read_buf_resp_msg);
> +			buf = ((struct ucsi_read_buf_resp_msg *)data)->buf;
> +			buf_len = UCSI_BUF_V1_SIZE;
> +		}
> +	} else {
> +		dev_err(ucsi->dev, "UCSI version not set\n");
> +		return;
> +	}

I don't really see when you could enter that else statement?

> -	if (resp->ret_code)
> +	if (len > max_len)
> +		return;
> +
> +	if (buf_len > len - sizeof(struct pmic_glink_hdr) - sizeof(u32))
> +		buf_len = len - sizeof(struct pmic_glink_hdr) - sizeof(u32);
> +
> +	memcpy(&ret_code, buf + sizeof(struct pmic_glink_hdr) + buf_len, sizeof(u32));
> +	if (ret_code)
>  		return;
>  
> -	memcpy(ucsi->read_buf, resp->buf, UCSI_BUF_SIZE);
> +	memcpy(ucsi->read_buf, buf, buf_len);
>  	complete(&ucsi->read_ack);
>  }

thanks,

-- 
heikki