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Date: Tue, 5 Mar 2024 03:06:55 +0000
From: Benson Leung <bleung@google.com>
To: Jameson Thies <jthies@google.com>
Cc: heikki.krogerus@linux.intel.com, linux-usb@vger.kernel.org,
	pmalani@chromium.org, abhishekpandit@chromium.org,
	andersson@kernel.org, dmitry.baryshkov@linaro.org,
	fabrice.gasnier@foss.st.com, gregkh@linuxfoundation.org,
	hdegoede@redhat.com, neil.armstrong@linaro.org,
	rajaram.regupathy@intel.com, saranya.gopal@intel.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 3/4] usb: typec: ucsi: Register SOP/SOP' Discover
 Identity Responses
Message-ID: <ZeaMT9pDZ3RWTp2O@google.com>
References: <20240305025804.1290919-1-jthies@google.com>
 <20240305025804.1290919-4-jthies@google.com>
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Hi Jameson,

On Tue, Mar 05, 2024 at 02:58:03AM +0000, Jameson Thies wrote:
> Register SOP and SOP' Discover Identity responses with the USB Type-C
> Connector Class as partner and cable identities, respectively. Discover
> Identity responses are requested from the PPM using the GET_PD_MESSAGE
> UCSI command.
>=20
> Signed-off-by: Jameson Thies <jthies@google.com>

Reviewed-by: Benson Leung <bleung@chromium.org>


> ---
> GET_PD_MESSAGE responses from the PPM populate partner and cable
> identity in sysfs:
> nospike-rev4 /sys/class/typec # ls port0-partner/identity/
> cert_stat  id_header  product  product_type_vdo1  product_type_vdo2
> product_type_vdo3
> nospike-rev4 /sys/class/typec # ls port0-cable/identity/
> cert_stat  id_header  product  product_type_vdo1  product_type_vdo2
> product_type_vdo3
>=20
> Changes in v4:
> - Cleaned up redundent ucsi_send_command calls for discovering identity.
>=20
> Changes in v3:
> - None.
>=20
> Changes in v2:
> - Re-ordered memset call and null assignment when unregistering partners
> and cables.
> - Supports registering partner and cable identity with UCSI versions
> before v2.0.
> - Shortened lines to within 80 characters with the exception of two
> error log lines with three indentations.
> - Tested on usb-testing branch merged with chromeOS 6.8-rc2 kernel.
>=20
> drivers/usb/typec/ucsi/ucsi.c | 112 ++++++++++++++++++++++++++++++++++
>  drivers/usb/typec/ucsi/ucsi.h |  29 +++++++++
>  2 files changed, 141 insertions(+)
>=20
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index 7c84687b5d1a3..3b64a0f51041c 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -646,6 +646,108 @@ static int ucsi_get_src_pdos(struct ucsi_connector =
*con)
>  	return ret;
>  }
> =20
> +static int ucsi_read_identity(struct ucsi_connector *con, u8 recipient,
> +			      u8 offset, u8 bytes, void *resp)
> +{
> +	struct ucsi *ucsi =3D con->ucsi;
> +	u64 command;
> +	int ret;
> +
> +	command =3D UCSI_COMMAND(UCSI_GET_PD_MESSAGE) |
> +	    UCSI_CONNECTOR_NUMBER(con->num);
> +	command |=3D UCSI_GET_PD_MESSAGE_RECIPIENT(recipient);
> +	command |=3D UCSI_GET_PD_MESSAGE_OFFSET(offset);
> +	command |=3D UCSI_GET_PD_MESSAGE_BYTES(bytes);
> +	command |=3D UCSI_GET_PD_MESSAGE_TYPE(UCSI_GET_PD_MESSAGE_TYPE_IDENTITY=
);
> +
> +	ret =3D ucsi_send_command(ucsi, command, resp, bytes);
> +	if (ret < 0)
> +		dev_err(ucsi->dev, "UCSI_GET_PD_MESSAGE failed (%d)\n", ret);
> +
> +	return ret;
> +}
> +
> +static int ucsi_get_identity(struct ucsi_connector *con, u8 recipient,
> +			      struct usb_pd_identity *id)
> +{
> +	struct ucsi *ucsi =3D con->ucsi;
> +	struct ucsi_pd_message_disc_id resp =3D {};
> +	int ret;
> +
> +	if (ucsi->version < UCSI_VERSION_2_0) {
> +		/*
> +		 * Before UCSI v2.0, MESSAGE_IN is 16 bytes which cannot fit
> +		 * the 28 byte identity response including the VDM header.
> +		 * First request the VDM header, ID Header VDO, Cert Stat VDO
> +		 * and Product VDO.
> +		 */
> +		ret =3D ucsi_read_identity(con, recipient, 0, 0x10, &resp);
> +		if (ret < 0)
> +			return ret;
> +
> +
> +		/* Then request Product Type VDO1 through Product Type VDO3. */
> +		ret =3D ucsi_read_identity(con, recipient, 0x10, 0xc,
> +					 &resp.vdo[0]);
> +		if (ret < 0)
> +			return ret;
> +
> +	} else {
> +		/*
> +		 * In UCSI v2.0 and after, MESSAGE_IN is large enough to request
> +		 * the large enough to request the full Discover Identity
> +		 * response at once.
> +		 */
> +		ret =3D ucsi_read_identity(con, recipient, 0x0, 0x1c, &resp);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	id->id_header =3D resp.id_header;
> +	id->cert_stat =3D resp.cert_stat;
> +	id->product =3D resp.product;
> +	id->vdo[0] =3D resp.vdo[0];
> +	id->vdo[1] =3D resp.vdo[1];
> +	id->vdo[2] =3D resp.vdo[2];
> +	return 0;
> +}
> +
> +static int ucsi_get_partner_identity(struct ucsi_connector *con)
> +{
> +	int ret;
> +
> +	ret =3D ucsi_get_identity(con, UCSI_RECIPIENT_SOP,
> +				 &con->partner_identity);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret =3D typec_partner_set_identity(con->partner);
> +	if (ret < 0) {
> +		dev_err(con->ucsi->dev, "Failed to set partner identity (%d)\n",
> +			ret);
> +	}
> +
> +	return ret;
> +}
> +
> +static int ucsi_get_cable_identity(struct ucsi_connector *con)
> +{
> +	int ret;
> +
> +	ret =3D ucsi_get_identity(con, UCSI_RECIPIENT_SOP_P,
> +				 &con->cable_identity);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret =3D typec_cable_set_identity(con->cable);
> +	if (ret < 0) {
> +		dev_err(con->ucsi->dev, "Failed to set cable identity (%d)\n",
> +			ret);
> +	}
> +
> +	return ret;
> +}
> +
>  static int ucsi_check_altmodes(struct ucsi_connector *con)
>  {
>  	int ret, num_partner_am;
> @@ -754,6 +856,7 @@ static int ucsi_register_cable(struct ucsi_connector =
*con)
>  		break;
>  	}
> =20
> +	desc.identity =3D &con->cable_identity;
>  	desc.active =3D !!(UCSI_CABLE_PROP_FLAG_ACTIVE_CABLE &
>  			 con->cable_prop.flags);
>  	desc.pd_revision =3D UCSI_CABLE_PROP_FLAG_PD_MAJOR_REV_AS_BCD(
> @@ -777,6 +880,7 @@ static void ucsi_unregister_cable(struct ucsi_connect=
or *con)
>  		return;
> =20
>  	typec_unregister_cable(con->cable);
> +	memset(&con->cable_identity, 0, sizeof(con->cable_identity));
>  	con->cable =3D NULL;
>  }
> =20
> @@ -827,6 +931,7 @@ static int ucsi_register_partner(struct ucsi_connecto=
r *con)
>  		break;
>  	}
> =20
> +	desc.identity =3D &con->partner_identity;
>  	desc.usb_pd =3D pwr_opmode =3D=3D UCSI_CONSTAT_PWR_OPMODE_PD;
>  	desc.pd_revision =3D UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->=
cap.flags);
> =20
> @@ -855,6 +960,7 @@ static void ucsi_unregister_partner(struct ucsi_conne=
ctor *con)
>  	ucsi_unregister_altmodes(con, UCSI_RECIPIENT_SOP);
>  	ucsi_unregister_cable(con);
>  	typec_unregister_partner(con->partner);
> +	memset(&con->partner_identity, 0, sizeof(con->partner_identity));
>  	con->partner =3D NULL;
>  }
> =20
> @@ -975,6 +1081,10 @@ static int ucsi_check_cable(struct ucsi_connector *=
con)
>  	if (ret < 0)
>  		return ret;
> =20
> +	ret =3D ucsi_get_cable_identity(con);
> +	if (ret < 0)
> +		return ret;
> +
>  	return 0;
>  }
> =20
> @@ -1019,6 +1129,7 @@ static void ucsi_handle_connector_change(struct wor=
k_struct *work)
>  			ucsi_register_partner(con);
>  			ucsi_partner_task(con, ucsi_check_connection, 1, HZ);
>  			ucsi_partner_task(con, ucsi_check_connector_capability, 1, HZ);
> +			ucsi_partner_task(con, ucsi_get_partner_identity, 1, HZ);
>  			ucsi_partner_task(con, ucsi_check_cable, 1, HZ);
> =20
>  			if (UCSI_CONSTAT_PWR_OPMODE(con->status.flags) =3D=3D
> @@ -1418,6 +1529,7 @@ static int ucsi_register_port(struct ucsi *ucsi, st=
ruct ucsi_connector *con)
>  		ucsi_register_partner(con);
>  		ucsi_pwr_opmode_change(con);
>  		ucsi_port_psy_changed(con);
> +		ucsi_get_partner_identity(con);
>  		ucsi_check_cable(con);
>  	}
> =20
> diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
> index f0aabef0b7c64..b89fae82e8ce7 100644
> --- a/drivers/usb/typec/ucsi/ucsi.h
> +++ b/drivers/usb/typec/ucsi/ucsi.h
> @@ -106,6 +106,7 @@ void ucsi_connector_change(struct ucsi *ucsi, u8 num);
>  #define UCSI_GET_CABLE_PROPERTY		0x11
>  #define UCSI_GET_CONNECTOR_STATUS	0x12
>  #define UCSI_GET_ERROR_STATUS		0x13
> +#define UCSI_GET_PD_MESSAGE		0x15
> =20
>  #define UCSI_CONNECTOR_NUMBER(_num_)		((u64)(_num_) << 16)
>  #define UCSI_COMMAND(_cmd_)			((_cmd_) & 0xff)
> @@ -159,6 +160,18 @@ void ucsi_connector_change(struct ucsi *ucsi, u8 num=
);
>  #define UCSI_MAX_PDOS				(4)
>  #define UCSI_GET_PDOS_SRC_PDOS			((u64)1 << 34)
> =20
> +/* GET_PD_MESSAGE command bits */
> +#define UCSI_GET_PD_MESSAGE_RECIPIENT(_r_)	((u64)(_r_) << 23)
> +#define UCSI_GET_PD_MESSAGE_OFFSET(_r_)		((u64)(_r_) << 26)
> +#define UCSI_GET_PD_MESSAGE_BYTES(_r_)		((u64)(_r_) << 34)
> +#define UCSI_GET_PD_MESSAGE_TYPE(_r_)		((u64)(_r_) << 42)
> +#define   UCSI_GET_PD_MESSAGE_TYPE_SNK_CAP_EXT	0
> +#define   UCSI_GET_PD_MESSAGE_TYPE_SRC_CAP_EXT	1
> +#define   UCSI_GET_PD_MESSAGE_TYPE_BAT_CAP	2
> +#define   UCSI_GET_PD_MESSAGE_TYPE_BAT_STAT	3
> +#define   UCSI_GET_PD_MESSAGE_TYPE_IDENTITY	4
> +#define   UCSI_GET_PD_MESSAGE_TYPE_REVISION	5
> +
>  /* ---------------------------------------------------------------------=
----- */
> =20
>  /* Error information returned by PPM in response to GET_ERROR_STATUS com=
mand. */
> @@ -338,6 +351,18 @@ struct ucsi_connector_status {
>  	((get_unaligned_le32(&(_p_)[5]) & GENMASK(16, 1)) >> 1)
>  } __packed;
> =20
> +/*
> + * Data structure filled by PPM in response to GET_PD_MESSAGE command wi=
th the
> + * Response Message Type set to Discover Identity Response.
> + */
> +struct ucsi_pd_message_disc_id {
> +	u32 vdm_header;
> +	u32 id_header;
> +	u32 cert_stat;
> +	u32 product;
> +	u32 vdo[3];
> +} __packed;
> +
>  /* ---------------------------------------------------------------------=
----- */
> =20
>  struct ucsi_debugfs_entry {
> @@ -428,6 +453,10 @@ struct ucsi_connector {
>  	struct usb_power_delivery_capabilities *partner_sink_caps;
> =20
>  	struct usb_role_switch *usb_role_sw;
> +
> +	/* USB PD identity */
> +	struct usb_pd_identity partner_identity;
> +	struct usb_pd_identity cable_identity;
>  };
> =20
>  int ucsi_send_command(struct ucsi *ucsi, u64 command,
> --=20
> 2.44.0.rc1.240.g4c46232300-goog
>=20

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