[PATCH v1 0/3] usb: typec: ucsi: Adding support for UCSI 3.0

[PATCH v1 0/3] usb: typec: ucsi: Adding support for UCSI 3.0

[Abhishek Pandit-Subedi]

From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>


Hi Heikki,

This series starts the work adding UCSI 3.0 support to the UCSI driver.

There's a couple of pieces to start here:
* Add version checks and limit read size on 1.2.
* Update Connector Status and Connector Capability structures.
* Expose Partner PD revision from Capability data.

These were tested against on a 6.6 kernel running a usermode PPM against
a Realtek Evaluation board.

One additional note: there are a lot more unaligned fields in UCSI now
and the struct definitions are getting a bit out of hand. We can discuss
alternate mechanisms for defining these structs in the patch that
changes these structures.

Thanks,
Abhishek


Abhishek Pandit-Subedi (3):
  usb: typec: ucsi: Limit read size on v1.2
  usb: typec: ucsi: Update connector cap and status
  usb: typec: ucsi: Get PD revision for partner

 drivers/usb/typec/ucsi/ucsi.c | 51 ++++++++++++++++++++++++++--
 drivers/usb/typec/ucsi/ucsi.h | 64 ++++++++++++++++++++++++++++++++---
 2 files changed, 109 insertions(+), 6 deletions(-)

-- 
2.43.0.429.g432eaa2c6b-goog

[PATCH v1 1/3] usb: typec: ucsi: Limit read size on v1.2

[Abhishek Pandit-Subedi]

From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>

Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was
increased from 16 to 256. In order to avoid overflowing reads for older
systems, add a mechanism to use the read UCSI version to truncate read
sizes on UCSI v1.2.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---
Tested on 6.6 kernel. Dmesg output from this change:
[  105.058162] ucsi_um_test ucsi_um_test_device.0: Registered UCSI
interface with version 3.0.0


 drivers/usb/typec/ucsi/ucsi.c | 26 ++++++++++++++++++++++++--
 drivers/usb/typec/ucsi/ucsi.h | 11 +++++++++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 5392ec698959..4edf785d203b 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -36,6 +36,19 @@
  */
 #define UCSI_SWAP_TIMEOUT_MS	5000
 
+static int ucsi_read_message_in(struct ucsi *ucsi, void *buf,
+					  size_t buf_size)
+{
+	/*
+	 * Below UCSI 2.0, MESSAGE_IN was limited to 16 bytes. Truncate the
+	 * reads here.
+	 */
+	if (ucsi->version <= UCSI_VERSION_1_2)
+		buf_size = min_t(size_t, 16, buf_size);
+
+	return ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, buf, buf_size);
+}
+
 static int ucsi_acknowledge_command(struct ucsi *ucsi)
 {
 	u64 ctrl;
@@ -72,7 +85,7 @@ static int ucsi_read_error(struct ucsi *ucsi)
 	if (ret < 0)
 		return ret;
 
-	ret = ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, &error, sizeof(error));
+	ret = ucsi_read_message_in(ucsi, &error, sizeof(error));
 	if (ret)
 		return ret;
 
@@ -170,7 +183,7 @@ int ucsi_send_command(struct ucsi *ucsi, u64 command,
 	length = ret;
 
 	if (data) {
-		ret = ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, data, size);
+		ret = ucsi_read_message_in(ucsi, data, size);
 		if (ret)
 			goto out;
 	}
@@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi)
 	if (!ucsi->version)
 		return -ENODEV;
 
+	/*
+	 * Version format is JJ.M.N (JJ = Major version, M = Minor version,
+	 * N = sub-minor version).
+	 */
+	dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x",
+		 UCSI_BCD_GET_MAJOR(ucsi->version),
+		 UCSI_BCD_GET_MINOR(ucsi->version),
+		 UCSI_BCD_GET_SUBMINOR(ucsi->version));
+
 	queue_delayed_work(system_long_wq, &ucsi->work, 0);
 
 	ucsi_debugfs_register(ucsi);
diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index 6478016d5cb8..bec920fa6b8a 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -23,6 +23,17 @@ struct dentry;
 #define UCSI_CONTROL			8
 #define UCSI_MESSAGE_IN			16
 #define UCSI_MESSAGE_OUT		32
+#define UCSIv2_MESSAGE_OUT		272
+
+/* UCSI versions */
+#define UCSI_VERSION_1_2	0x0120
+#define UCSI_VERSION_2_0	0x0200
+#define UCSI_VERSION_2_1	0x0210
+#define UCSI_VERSION_3_0	0x0300
+
+#define UCSI_BCD_GET_MAJOR(_v_)		(((_v_) >> 8) & 0xFF)
+#define UCSI_BCD_GET_MINOR(_v_)		(((_v_) >> 4) & 0x0F)
+#define UCSI_BCD_GET_SUBMINOR(_v_)	((_v_) & 0x0F)
 
 /* Command Status and Connector Change Indication (CCI) bits */
 #define UCSI_CCI_CONNECTOR(_c_)		(((_c_) & GENMASK(7, 1)) >> 1)
-- 
2.43.0.429.g432eaa2c6b-goog

[PATCH v1 2/3] usb: typec: ucsi: Update connector cap and status

[Abhishek Pandit-Subedi]

From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>

Update the data structures for ucsi_connector_capability and
ucsi_connector_status to UCSIv3.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---
Connector status has several unaligned bitfields (16-bit) that result in
difficult to maintain macros. It may be better if we simply re-define
these structs as u8[] and add bit range macros to access and cast these
values.

i.e.
struct ucsi_connector_status {
  u8 raw_data[18];

...
\#define UCSI_CONSTAT_CONNECTOR_STATUS          FIELD(u16, 15, 0)
\#define UCSI_CONSTAT_BCD_PD_VER_OPER_MODE      FIELD(u16, 85, 70)
}

GET_UCSI_FIELD(con->status, UCSI_CONSTAT_CONNECTOR_STATUS);
SET_UCSI_FIELD(con->status, UCSI_CONSTAT_CONNECTOR_STATUS, 0);

I didn't find a clear example of an existing mechanism to do this. Would
love some pointers here if it already exists and some feedback from the
maintainer if this is a direction you want to go.


 drivers/usb/typec/ucsi/ucsi.h | 50 ++++++++++++++++++++++++++++++++---
 1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index bec920fa6b8a..94b373378f63 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -3,6 +3,7 @@
 #ifndef __DRIVER_USB_TYPEC_UCSI_H
 #define __DRIVER_USB_TYPEC_UCSI_H
 
+#include <asm-generic/unaligned.h>
 #include <linux/bitops.h>
 #include <linux/device.h>
 #include <linux/power_supply.h>
@@ -214,9 +215,29 @@ struct ucsi_connector_capability {
 #define UCSI_CONCAP_OPMODE_USB2			BIT(5)
 #define UCSI_CONCAP_OPMODE_USB3			BIT(6)
 #define UCSI_CONCAP_OPMODE_ALT_MODE		BIT(7)
-	u8 flags;
+	u32 flags;
 #define UCSI_CONCAP_FLAG_PROVIDER		BIT(0)
 #define UCSI_CONCAP_FLAG_CONSUMER		BIT(1)
+#define UCSI_CONCAP_FLAG_SWAP_TO_DFP		BIT(2)
+#define UCSI_CONCAP_FLAG_SWAP_TO_UFP		BIT(3)
+#define UCSI_CONCAP_FLAG_SWAP_TO_SRC		BIT(4)
+#define UCSI_CONCAP_FLAG_SWAP_TO_SINK		BIT(5)
+#define UCSI_CONCAP_FLAG_EX_OP_MODE(_f_) \
+	(((_f_) & GENMASK(13, 6)) >> 6)
+#define   UCSI_CONCAP_EX_OP_MODE_USB4_GEN2	BIT(0)
+#define   UCSI_CONCAP_EX_OP_MODE_EPR_SRC	BIT(1)
+#define   UCSI_CONCAP_EX_OP_MODE_EPR_SINK	BIT(2)
+#define   UCSI_CONCAP_EX_OP_MODE_USB4_GEN3	BIT(3)
+#define   UCSI_CONCAP_EX_OP_MODE_USB4_GEN4	BIT(4)
+#define UCSI_CONCAP_FLAG_MISC_CAPS(_f_) \
+	(((_f_) & GENMASK(17, 14)) >> 14)
+#define   UCSI_CONCAP_MISC_CAP_FW_UPDATE	BIT(0)
+#define   UCSI_CONCAP_MISC_CAP_SECURITY		BIT(1)
+#define UCSI_CONCAP_FLAG_REV_CURR_PROT_SUPPORT	BIT(18)
+#define UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV(_f_) \
+	(((_f_) & GENMASK(20, 19)) >> 19)
+#define UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(_f_) \
+	(UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV(_f_) << 8)
 } __packed;
 
 struct ucsi_altmode {
@@ -276,15 +297,36 @@ struct ucsi_connector_status {
 #define   UCSI_CONSTAT_PARTNER_TYPE_DEBUG	5
 #define   UCSI_CONSTAT_PARTNER_TYPE_AUDIO	6
 	u32 request_data_obj;
-	u8 pwr_status;
-#define UCSI_CONSTAT_BC_STATUS(_p_)		((_p_) & GENMASK(2, 0))
+
+	u8 pwr_status[3];
+#define UCSI_CONSTAT_BC_STATUS(_p_)		((_p_[0]) & GENMASK(1, 0))
 #define   UCSI_CONSTAT_BC_NOT_CHARGING		0
 #define   UCSI_CONSTAT_BC_NOMINAL_CHARGING	1
 #define   UCSI_CONSTAT_BC_SLOW_CHARGING		2
 #define   UCSI_CONSTAT_BC_TRICKLE_CHARGING	3
-#define UCSI_CONSTAT_PROVIDER_CAP_LIMIT(_p_)	(((_p_) & GENMASK(6, 3)) >> 3)
+#define UCSI_CONSTAT_PROVIDER_CAP_LIMIT(_p_)	(((_p_[0]) & GENMASK(5, 2)) >> 2)
 #define   UCSI_CONSTAT_CAP_PWR_LOWERED		0
 #define   UCSI_CONSTAT_CAP_PWR_BUDGET_LIMIT	1
+#define UCSI_CONSTAT_PROVIDER_PD_VERSION_OPER_MODE(_p_)	\
+	((get_unaligned_le32(_p_) & GENMASK(21, 6)) >> 6)
+#define UCSI_CONSTAT_ORIENTATION(_p_)		(((_p_[2]) & GENMASK(6, 6)) >> 6)
+#define   UCSI_CONSTAT_ORIENTATION_DIRECT	0
+#define   UCSI_CONSTAT_ORIENTATION_FLIPPED	1
+#define UCSI_CONSTAT_SINK_PATH_STATUS(_p_)	(((_p_[2]) & GENMASK(7, 7)) >> 7)
+#define   UCSI_CONSTAT_SINK_PATH_DISABLED	0
+#define   UCSI_CONSTAT_SINK_PATH_ENABLED	1
+	u8 pwr_readings[9];
+#define UCSI_CONSTAT_REV_CURR_PROT_STATUS(_p_)	((_p_[0]) & 0x1)
+#define UCSI_CONSTAT_PWR_READING_VALID(_p_)	(((_p_[0]) & GENMASK(1, 1)) >> 1)
+#define UCSI_CONSTAT_CURRENT_SCALE(_p_)		(((_p_[0]) & GENMASK(4, 2)) >> 2)
+#define UCSI_CONSTAT_PEAK_CURRENT(_p_) \
+	((get_unaligned_le32(_p_) & GENMASK(20, 5)) >> 5)
+#define UCSI_CONSTAT_AVG_CURRENT(_p_) \
+	((get_unaligned_le32(&(_p_)[2]) & GENMASK(20, 5)) >> 5)
+#define UCSI_CONSTAT_VOLTAGE_SCALE(_p_) \
+	((get_unaligned_le16(&(_p_)[4]) & GENMASK(8, 5)) >> 5)
+#define UCSI_CONSTAT_VOLTAGE_READING(_p_) \
+	((get_unaligned_le32(&(_p_)[5]) & GENMASK(16, 1)) >> 1)
 } __packed;
 
 /* -------------------------------------------------------------------------- */
-- 
2.43.0.429.g432eaa2c6b-goog

[PATCH v1 3/3] usb: typec: ucsi: Get PD revision for partner

[Abhishek Pandit-Subedi]

From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>

PD major revision for the port partner is described in
GET_CONNECTOR_CAPABILITY and is only valid on UCSI 2.0 and newer. Update
the pd_revision on the partner if the UCSI version is 2.0 or newer.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---
$ cat /sys/class/typec/port2-partner/usb_power_delivery_revision
3.0

 drivers/usb/typec/ucsi/ucsi.c | 25 +++++++++++++++++++++++++
 drivers/usb/typec/ucsi/ucsi.h |  3 +++
 2 files changed, 28 insertions(+)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 4edf785d203b..8e0a512853ba 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -782,6 +782,8 @@ static int ucsi_register_partner(struct ucsi_connector *con)
 	}
 
 	desc.usb_pd = pwr_opmode == UCSI_CONSTAT_PWR_OPMODE_PD;
+	desc.pd_revision =
+		UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags);
 
 	partner = typec_register_partner(con->port, &desc);
 	if (IS_ERR(partner)) {
@@ -856,6 +858,28 @@ static void ucsi_partner_change(struct ucsi_connector *con)
 			con->num, u_role);
 }
 
+static int ucsi_check_connector_capability(struct ucsi_connector *con)
+{
+	u64 command;
+	int ret;
+
+	if (!con->partner && !IS_MIN_VERSION_2_0(con->ucsi))
+		return 0;
+
+	command = UCSI_GET_CONNECTOR_CAPABILITY | UCSI_CONNECTOR_NUMBER(con->num);
+	ret = ucsi_send_command(con->ucsi, command, &con->cap, sizeof(con->cap));
+	if (ret < 0) {
+		dev_err(con->ucsi->dev, "GET_CONNECTOR_CAPABILITY failed (%d)\n", ret);
+		return ret;
+	}
+
+	typec_partner_set_pd_revision(
+		con->partner,
+		UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags));
+
+	return ret;
+}
+
 static int ucsi_check_connection(struct ucsi_connector *con)
 {
 	u8 prev_flags = con->status.flags;
@@ -925,6 +949,7 @@ static void ucsi_handle_connector_change(struct work_struct *work)
 		if (con->status.flags & UCSI_CONSTAT_CONNECTED) {
 			ucsi_register_partner(con);
 			ucsi_partner_task(con, ucsi_check_connection, 1, HZ);
+			ucsi_partner_task(con, ucsi_check_connector_capability, 1, HZ);
 
 			if (UCSI_CONSTAT_PWR_OPMODE(con->status.flags) ==
 			    UCSI_CONSTAT_PWR_OPMODE_PD)
diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index 94b373378f63..5e60328f398e 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -36,6 +36,9 @@ struct dentry;
 #define UCSI_BCD_GET_MINOR(_v_)		(((_v_) >> 4) & 0x0F)
 #define UCSI_BCD_GET_SUBMINOR(_v_)	((_v_) & 0x0F)
 
+#define IS_MIN_VERSION(ucsi, min_ver)	((ucsi)->version >= min_ver)
+#define IS_MIN_VERSION_2_0(ucsi)	IS_MIN_VERSION(ucsi, UCSI_VERSION_2_0)
+
 /* Command Status and Connector Change Indication (CCI) bits */
 #define UCSI_CCI_CONNECTOR(_c_)		(((_c_) & GENMASK(7, 1)) >> 1)
 #define UCSI_CCI_LENGTH(_c_)		(((_c_) & GENMASK(15, 8)) >> 8)
-- 
2.43.0.429.g432eaa2c6b-goog

Re: [PATCH v1 1/3] usb: typec: ucsi: Limit read size on v1.2

[Prashant Malani]

Hi Abhishek,

On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
<abhishekpandit@google.com> wrote:
>
> From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
>
> Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was
> increased from 16 to 256. In order to avoid overflowing reads for older
> systems, add a mechanism to use the read UCSI version to truncate read
> sizes on UCSI v1.2.
>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
I have one nit (mentioned in side-band but reproducing here for consistency),
but will defer to the maintainer on that.

The above notwithstanding, FWIW:
Reviewed-by: Prashant Malani<pmalani@chromium.org>

> @@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi)
>         if (!ucsi->version)
>                 return -ENODEV;
>
> +       /*
> +        * Version format is JJ.M.N (JJ = Major version, M = Minor version,
> +        * N = sub-minor version).
> +        */
> +       dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x",
> +                UCSI_BCD_GET_MAJOR(ucsi->version),
> +                UCSI_BCD_GET_MINOR(ucsi->version),
> +                UCSI_BCD_GET_SUBMINOR(ucsi->version));

nit: I think this doesn't need to be dev_info() and can be just
dev_dbg(), but will
defer to the maintainer.

Thanks,

-Prashant

Re: [PATCH v1 0/3] usb: typec: ucsi: Adding support for UCSI 3.0

[Neil Armstrong]

On 23/01/2024 23:30, Abhishek Pandit-Subedi wrote:
> From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> 
> 
> Hi Heikki,
> 
> This series starts the work adding UCSI 3.0 support to the UCSI driver.
> 
> There's a couple of pieces to start here:
> * Add version checks and limit read size on 1.2.
> * Update Connector Status and Connector Capability structures.
> * Expose Partner PD revision from Capability data.
> 
> These were tested against on a 6.6 kernel running a usermode PPM against
> a Realtek Evaluation board.
> 
> One additional note: there are a lot more unaligned fields in UCSI now
> and the struct definitions are getting a bit out of hand. We can discuss
> alternate mechanisms for defining these structs in the patch that
> changes these structures.
> 
> Thanks,
> Abhishek
> 
> 
> Abhishek Pandit-Subedi (3):
>    usb: typec: ucsi: Limit read size on v1.2
>    usb: typec: ucsi: Update connector cap and status
>    usb: typec: ucsi: Get PD revision for partner
> 
>   drivers/usb/typec/ucsi/ucsi.c | 51 ++++++++++++++++++++++++++--
>   drivers/usb/typec/ucsi/ucsi.h | 64 ++++++++++++++++++++++++++++++++---
>   2 files changed, 109 insertions(+), 6 deletions(-)
> 

[    7.417925] ucsi_glink.pmic_glink_ucsi pmic_glink.ucsi.0: Registered UCSI interface with version 1.1.0

Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD

[    9.085733] ucsi_glink.pmic_glink_ucsi pmic_glink.ucsi.0: Registered UCSI interface with version 1.1.0

Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD

Thanks,
Neil

Re: [PATCH v1 1/3] usb: typec: ucsi: Limit read size on v1.2

[Heikki Krogerus]

On Wed, Jan 24, 2024 at 12:12:26AM -0800, Prashant Malani wrote:
> Hi Abhishek,
> 
> On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
> <abhishekpandit@google.com> wrote:
> >
> > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> >
> > Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was
> > increased from 16 to 256. In order to avoid overflowing reads for older
> > systems, add a mechanism to use the read UCSI version to truncate read
> > sizes on UCSI v1.2.
> >
> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> I have one nit (mentioned in side-band but reproducing here for consistency),
> but will defer to the maintainer on that.
> 
> The above notwithstanding, FWIW:
> Reviewed-by: Prashant Malani<pmalani@chromium.org>
> 
> > @@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi)
> >         if (!ucsi->version)
> >                 return -ENODEV;
> >
> > +       /*
> > +        * Version format is JJ.M.N (JJ = Major version, M = Minor version,
> > +        * N = sub-minor version).
> > +        */
> > +       dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x",
> > +                UCSI_BCD_GET_MAJOR(ucsi->version),
> > +                UCSI_BCD_GET_MINOR(ucsi->version),
> > +                UCSI_BCD_GET_SUBMINOR(ucsi->version));
> 
> nit: I think this doesn't need to be dev_info() and can be just
> dev_dbg(), but will
> defer to the maintainer.

I think that's okay.

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

-- 
heikki

Re: [PATCH v1 2/3] usb: typec: ucsi: Update connector cap and status

[Heikki Krogerus]

On Tue, Jan 23, 2024 at 02:30:35PM -0800, Abhishek Pandit-Subedi wrote:
> From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> 
> Update the data structures for ucsi_connector_capability and
> ucsi_connector_status to UCSIv3.
> 
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> Connector status has several unaligned bitfields (16-bit) that result in
> difficult to maintain macros. It may be better if we simply re-define
> these structs as u8[] and add bit range macros to access and cast these
> values.
> 
> i.e.
> struct ucsi_connector_status {
>   u8 raw_data[18];
> 
> ...
> \#define UCSI_CONSTAT_CONNECTOR_STATUS          FIELD(u16, 15, 0)
> \#define UCSI_CONSTAT_BCD_PD_VER_OPER_MODE      FIELD(u16, 85, 70)
> }
> 
> GET_UCSI_FIELD(con->status, UCSI_CONSTAT_CONNECTOR_STATUS);
> SET_UCSI_FIELD(con->status, UCSI_CONSTAT_CONNECTOR_STATUS, 0);
> 
> I didn't find a clear example of an existing mechanism to do this. Would
> love some pointers here if it already exists and some feedback from the
> maintainer if this is a direction you want to go.

I'll ask around if anybody has any ideas on our side, but I think we
can go forward with this in any case. We can always fine tune these
later.

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

>  drivers/usb/typec/ucsi/ucsi.h | 50 ++++++++++++++++++++++++++++++++---
>  1 file changed, 46 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
> index bec920fa6b8a..94b373378f63 100644
> --- a/drivers/usb/typec/ucsi/ucsi.h
> +++ b/drivers/usb/typec/ucsi/ucsi.h
> @@ -3,6 +3,7 @@
>  #ifndef __DRIVER_USB_TYPEC_UCSI_H
>  #define __DRIVER_USB_TYPEC_UCSI_H
>  
> +#include <asm-generic/unaligned.h>
>  #include <linux/bitops.h>
>  #include <linux/device.h>
>  #include <linux/power_supply.h>
> @@ -214,9 +215,29 @@ struct ucsi_connector_capability {
>  #define UCSI_CONCAP_OPMODE_USB2			BIT(5)
>  #define UCSI_CONCAP_OPMODE_USB3			BIT(6)
>  #define UCSI_CONCAP_OPMODE_ALT_MODE		BIT(7)
> -	u8 flags;
> +	u32 flags;
>  #define UCSI_CONCAP_FLAG_PROVIDER		BIT(0)
>  #define UCSI_CONCAP_FLAG_CONSUMER		BIT(1)
> +#define UCSI_CONCAP_FLAG_SWAP_TO_DFP		BIT(2)
> +#define UCSI_CONCAP_FLAG_SWAP_TO_UFP		BIT(3)
> +#define UCSI_CONCAP_FLAG_SWAP_TO_SRC		BIT(4)
> +#define UCSI_CONCAP_FLAG_SWAP_TO_SINK		BIT(5)
> +#define UCSI_CONCAP_FLAG_EX_OP_MODE(_f_) \
> +	(((_f_) & GENMASK(13, 6)) >> 6)
> +#define   UCSI_CONCAP_EX_OP_MODE_USB4_GEN2	BIT(0)
> +#define   UCSI_CONCAP_EX_OP_MODE_EPR_SRC	BIT(1)
> +#define   UCSI_CONCAP_EX_OP_MODE_EPR_SINK	BIT(2)
> +#define   UCSI_CONCAP_EX_OP_MODE_USB4_GEN3	BIT(3)
> +#define   UCSI_CONCAP_EX_OP_MODE_USB4_GEN4	BIT(4)
> +#define UCSI_CONCAP_FLAG_MISC_CAPS(_f_) \
> +	(((_f_) & GENMASK(17, 14)) >> 14)
> +#define   UCSI_CONCAP_MISC_CAP_FW_UPDATE	BIT(0)
> +#define   UCSI_CONCAP_MISC_CAP_SECURITY		BIT(1)
> +#define UCSI_CONCAP_FLAG_REV_CURR_PROT_SUPPORT	BIT(18)
> +#define UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV(_f_) \
> +	(((_f_) & GENMASK(20, 19)) >> 19)
> +#define UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(_f_) \
> +	(UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV(_f_) << 8)
>  } __packed;
>  
>  struct ucsi_altmode {
> @@ -276,15 +297,36 @@ struct ucsi_connector_status {
>  #define   UCSI_CONSTAT_PARTNER_TYPE_DEBUG	5
>  #define   UCSI_CONSTAT_PARTNER_TYPE_AUDIO	6
>  	u32 request_data_obj;
> -	u8 pwr_status;
> -#define UCSI_CONSTAT_BC_STATUS(_p_)		((_p_) & GENMASK(2, 0))
> +
> +	u8 pwr_status[3];
> +#define UCSI_CONSTAT_BC_STATUS(_p_)		((_p_[0]) & GENMASK(1, 0))
>  #define   UCSI_CONSTAT_BC_NOT_CHARGING		0
>  #define   UCSI_CONSTAT_BC_NOMINAL_CHARGING	1
>  #define   UCSI_CONSTAT_BC_SLOW_CHARGING		2
>  #define   UCSI_CONSTAT_BC_TRICKLE_CHARGING	3
> -#define UCSI_CONSTAT_PROVIDER_CAP_LIMIT(_p_)	(((_p_) & GENMASK(6, 3)) >> 3)
> +#define UCSI_CONSTAT_PROVIDER_CAP_LIMIT(_p_)	(((_p_[0]) & GENMASK(5, 2)) >> 2)
>  #define   UCSI_CONSTAT_CAP_PWR_LOWERED		0
>  #define   UCSI_CONSTAT_CAP_PWR_BUDGET_LIMIT	1
> +#define UCSI_CONSTAT_PROVIDER_PD_VERSION_OPER_MODE(_p_)	\
> +	((get_unaligned_le32(_p_) & GENMASK(21, 6)) >> 6)
> +#define UCSI_CONSTAT_ORIENTATION(_p_)		(((_p_[2]) & GENMASK(6, 6)) >> 6)
> +#define   UCSI_CONSTAT_ORIENTATION_DIRECT	0
> +#define   UCSI_CONSTAT_ORIENTATION_FLIPPED	1
> +#define UCSI_CONSTAT_SINK_PATH_STATUS(_p_)	(((_p_[2]) & GENMASK(7, 7)) >> 7)
> +#define   UCSI_CONSTAT_SINK_PATH_DISABLED	0
> +#define   UCSI_CONSTAT_SINK_PATH_ENABLED	1
> +	u8 pwr_readings[9];
> +#define UCSI_CONSTAT_REV_CURR_PROT_STATUS(_p_)	((_p_[0]) & 0x1)
> +#define UCSI_CONSTAT_PWR_READING_VALID(_p_)	(((_p_[0]) & GENMASK(1, 1)) >> 1)
> +#define UCSI_CONSTAT_CURRENT_SCALE(_p_)		(((_p_[0]) & GENMASK(4, 2)) >> 2)
> +#define UCSI_CONSTAT_PEAK_CURRENT(_p_) \
> +	((get_unaligned_le32(_p_) & GENMASK(20, 5)) >> 5)
> +#define UCSI_CONSTAT_AVG_CURRENT(_p_) \
> +	((get_unaligned_le32(&(_p_)[2]) & GENMASK(20, 5)) >> 5)
> +#define UCSI_CONSTAT_VOLTAGE_SCALE(_p_) \
> +	((get_unaligned_le16(&(_p_)[4]) & GENMASK(8, 5)) >> 5)
> +#define UCSI_CONSTAT_VOLTAGE_READING(_p_) \
> +	((get_unaligned_le32(&(_p_)[5]) & GENMASK(16, 1)) >> 1)
>  } __packed;
>  
>  /* -------------------------------------------------------------------------- */
> -- 
> 2.43.0.429.g432eaa2c6b-goog

-- 
heikki

Re: [PATCH v1 1/3] usb: typec: ucsi: Limit read size on v1.2

[Greg Kroah-Hartman]

On Wed, Jan 24, 2024 at 03:51:58PM +0200, Heikki Krogerus wrote:
> On Wed, Jan 24, 2024 at 12:12:26AM -0800, Prashant Malani wrote:
> > Hi Abhishek,
> > 
> > On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
> > <abhishekpandit@google.com> wrote:
> > >
> > > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > >
> > > Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was
> > > increased from 16 to 256. In order to avoid overflowing reads for older
> > > systems, add a mechanism to use the read UCSI version to truncate read
> > > sizes on UCSI v1.2.
> > >
> > > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > I have one nit (mentioned in side-band but reproducing here for consistency),
> > but will defer to the maintainer on that.
> > 
> > The above notwithstanding, FWIW:
> > Reviewed-by: Prashant Malani<pmalani@chromium.org>
> > 
> > > @@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi)
> > >         if (!ucsi->version)
> > >                 return -ENODEV;
> > >
> > > +       /*
> > > +        * Version format is JJ.M.N (JJ = Major version, M = Minor version,
> > > +        * N = sub-minor version).
> > > +        */
> > > +       dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x",
> > > +                UCSI_BCD_GET_MAJOR(ucsi->version),
> > > +                UCSI_BCD_GET_MINOR(ucsi->version),
> > > +                UCSI_BCD_GET_SUBMINOR(ucsi->version));
> > 
> > nit: I think this doesn't need to be dev_info() and can be just
> > dev_dbg(), but will
> > defer to the maintainer.
> 
> I think that's okay.
> 
> Reviewewd-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

No, when drivers are working properly they are quiet, this needs to be
dev_dbg().

thanks,

greg k-h

Re: [PATCH v1 3/3] usb: typec: ucsi: Get PD revision for partner

[Heikki Krogerus]

Hi Abhishek,

Few nitpicks for this one.

On Tue, Jan 23, 2024 at 02:30:36PM -0800, Abhishek Pandit-Subedi wrote:
> From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> 
> PD major revision for the port partner is described in
> GET_CONNECTOR_CAPABILITY and is only valid on UCSI 2.0 and newer. Update
> the pd_revision on the partner if the UCSI version is 2.0 or newer.
> 
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> $ cat /sys/class/typec/port2-partner/usb_power_delivery_revision
> 3.0
> 
>  drivers/usb/typec/ucsi/ucsi.c | 25 +++++++++++++++++++++++++
>  drivers/usb/typec/ucsi/ucsi.h |  3 +++
>  2 files changed, 28 insertions(+)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index 4edf785d203b..8e0a512853ba 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -782,6 +782,8 @@ static int ucsi_register_partner(struct ucsi_connector *con)
>  	}
>  
>  	desc.usb_pd = pwr_opmode == UCSI_CONSTAT_PWR_OPMODE_PD;
> +	desc.pd_revision =
> +		UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags);

	desc.pd_revision = UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags);

>  	partner = typec_register_partner(con->port, &desc);
>  	if (IS_ERR(partner)) {
> @@ -856,6 +858,28 @@ static void ucsi_partner_change(struct ucsi_connector *con)
>  			con->num, u_role);
>  }
>  
> +static int ucsi_check_connector_capability(struct ucsi_connector *con)
> +{
> +	u64 command;
> +	int ret;
> +
> +	if (!con->partner && !IS_MIN_VERSION_2_0(con->ucsi))
> +		return 0;
> +
> +	command = UCSI_GET_CONNECTOR_CAPABILITY | UCSI_CONNECTOR_NUMBER(con->num);
> +	ret = ucsi_send_command(con->ucsi, command, &con->cap, sizeof(con->cap));
> +	if (ret < 0) {
> +		dev_err(con->ucsi->dev, "GET_CONNECTOR_CAPABILITY failed (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	typec_partner_set_pd_revision(
> +		con->partner,
> +		UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags));

	typec_partner_set_pd_revision(con->partner,
		UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags));

> +
> +	return ret;
> +}
> +
>  static int ucsi_check_connection(struct ucsi_connector *con)
>  {
>  	u8 prev_flags = con->status.flags;
> @@ -925,6 +949,7 @@ static void ucsi_handle_connector_change(struct work_struct *work)
>  		if (con->status.flags & UCSI_CONSTAT_CONNECTED) {
>  			ucsi_register_partner(con);
>  			ucsi_partner_task(con, ucsi_check_connection, 1, HZ);
> +			ucsi_partner_task(con, ucsi_check_connector_capability, 1, HZ);
>  
>  			if (UCSI_CONSTAT_PWR_OPMODE(con->status.flags) ==
>  			    UCSI_CONSTAT_PWR_OPMODE_PD)
> diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
> index 94b373378f63..5e60328f398e 100644
> --- a/drivers/usb/typec/ucsi/ucsi.h
> +++ b/drivers/usb/typec/ucsi/ucsi.h
> @@ -36,6 +36,9 @@ struct dentry;
>  #define UCSI_BCD_GET_MINOR(_v_)		(((_v_) >> 4) & 0x0F)
>  #define UCSI_BCD_GET_SUBMINOR(_v_)	((_v_) & 0x0F)
>  
> +#define IS_MIN_VERSION(ucsi, min_ver)	((ucsi)->version >= min_ver)

Probable better to use brackets also with that min_ver:

#define IS_MIN_VERSION(ucsi, min_ver)	((ucsi)->version >= (min_ver))

> +#define IS_MIN_VERSION_2_0(ucsi)	IS_MIN_VERSION(ucsi, UCSI_VERSION_2_0)
> +
>  /* Command Status and Connector Change Indication (CCI) bits */
>  #define UCSI_CCI_CONNECTOR(_c_)		(((_c_) & GENMASK(7, 1)) >> 1)
>  #define UCSI_CCI_LENGTH(_c_)		(((_c_) & GENMASK(15, 8)) >> 8)
> -- 
> 2.43.0.429.g432eaa2c6b-goog

thanks,

-- 
heikki

Re: [PATCH v1 3/3] usb: typec: ucsi: Get PD revision for partner

[Prashant Malani]

Hi Abhishek,

On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
<abhishekpandit@google.com> wrote:
>
> From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
>
> PD major revision for the port partner is described in
> GET_CONNECTOR_CAPABILITY and is only valid on UCSI 2.0 and newer. Update
> the pd_revision on the partner if the UCSI version is 2.0 or newer.
>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> $ cat /sys/class/typec/port2-partner/usb_power_delivery_revision
> 3.0
>
>  drivers/usb/typec/ucsi/ucsi.c | 25 +++++++++++++++++++++++++
>  drivers/usb/typec/ucsi/ucsi.h |  3 +++
>  2 files changed, 28 insertions(+)
>
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index 4edf785d203b..8e0a512853ba 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -782,6 +782,8 @@ static int ucsi_register_partner(struct ucsi_connector *con)
>         }
>
>         desc.usb_pd = pwr_opmode == UCSI_CONSTAT_PWR_OPMODE_PD;
> +       desc.pd_revision =
> +               UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags);
>
>         partner = typec_register_partner(con->port, &desc);
>         if (IS_ERR(partner)) {
> @@ -856,6 +858,28 @@ static void ucsi_partner_change(struct ucsi_connector *con)
>                         con->num, u_role);
>  }
>
> +static int ucsi_check_connector_capability(struct ucsi_connector *con)
> +{
> +       u64 command;
> +       int ret;
> +
> +       if (!con->partner && !IS_MIN_VERSION_2_0(con->ucsi))

(Mentioned side-band but reproducing here for consistency)
This macro is unnecessary. It's just doing a comparison, which can be inlined
without any perceptible change in readability (actually, I'd argue adding the !
to an english idiom makes things *less* readable):

        if (!con->partner && con->ucsi->version < UCSI_VERSION_2_0)
               return 0;

Besides that, I think you want an || operator instead of the && operator, right?

> +               return 0;
> +
> +       command = UCSI_GET_CONNECTOR_CAPABILITY | UCSI_CONNECTOR_NUMBER(con->num);
> +       ret = ucsi_send_command(con->ucsi, command, &con->cap, sizeof(con->cap));
> +       if (ret < 0) {
> +               dev_err(con->ucsi->dev, "GET_CONNECTOR_CAPABILITY failed (%d)\n", ret);
> +               return ret;
> +       }
> +
> +       typec_partner_set_pd_revision(
> +               con->partner,
> +               UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags));
> +
> +       return ret;
> +}
> +
>  static int ucsi_check_connection(struct ucsi_connector *con)
>  {
>         u8 prev_flags = con->status.flags;

Thanks,

Re: [PATCH v1 2/3] usb: typec: ucsi: Update connector cap and status

[Prashant Malani]

Hi Abhishek,

On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
<abhishekpandit@google.com> wrote:
>
> From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
>
> Update the data structures for ucsi_connector_capability and
> ucsi_connector_status to UCSIv3.
>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Prashant Malani <pmalani@chromium.org>

BR,

Re: [PATCH v1 1/3] usb: typec: ucsi: Limit read size on v1.2

[Abhishek Pandit-Subedi]

Ack. Will make dev_dbg on the next iteration.

This seems like a good addition to the style guide too:
https://www.kernel.org/doc/html/v6.7/process/coding-style.html#printing-kernel-messages.
"When drivers are working properly, they are quiet. Prefer to use
DEBUG messages unless something is wrong."

What do you think Greg?

On Wed, Jan 24, 2024 at 6:17 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Wed, Jan 24, 2024 at 03:51:58PM +0200, Heikki Krogerus wrote:
> > On Wed, Jan 24, 2024 at 12:12:26AM -0800, Prashant Malani wrote:
> > > Hi Abhishek,
> > >
> > > On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
> > > <abhishekpandit@google.com> wrote:
> > > >
> > > > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > > >
> > > > Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was
> > > > increased from 16 to 256. In order to avoid overflowing reads for older
> > > > systems, add a mechanism to use the read UCSI version to truncate read
> > > > sizes on UCSI v1.2.
> > > >
> > > > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > > I have one nit (mentioned in side-band but reproducing here for consistency),
> > > but will defer to the maintainer on that.
> > >
> > > The above notwithstanding, FWIW:
> > > Reviewed-by: Prashant Malani<pmalani@chromium.org>
> > >
> > > > @@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi)
> > > >         if (!ucsi->version)
> > > >                 return -ENODEV;
> > > >
> > > > +       /*
> > > > +        * Version format is JJ.M.N (JJ = Major version, M = Minor version,
> > > > +        * N = sub-minor version).
> > > > +        */
> > > > +       dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x",
> > > > +                UCSI_BCD_GET_MAJOR(ucsi->version),
> > > > +                UCSI_BCD_GET_MINOR(ucsi->version),
> > > > +                UCSI_BCD_GET_SUBMINOR(ucsi->version));
> > >
> > > nit: I think this doesn't need to be dev_info() and can be just
> > > dev_dbg(), but will
> > > defer to the maintainer.
> >
> > I think that's okay.
> >
> > Reviewewd-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
>
> No, when drivers are working properly they are quiet, this needs to be
> dev_dbg().
>
> thanks,
>
> greg k-h
>

Re: [PATCH v1 3/3] usb: typec: ucsi: Get PD revision for partner

[Abhishek Pandit-Subedi]

On Wed, Jan 24, 2024 at 10:49 AM Prashant Malani <pmalani@chromium.org> wrote:
>
> Hi Abhishek,
>
> On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
> <abhishekpandit@google.com> wrote:
> >
> > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> >
> > PD major revision for the port partner is described in
> > GET_CONNECTOR_CAPABILITY and is only valid on UCSI 2.0 and newer. Update
> > the pd_revision on the partner if the UCSI version is 2.0 or newer.
> >
> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > ---
> > $ cat /sys/class/typec/port2-partner/usb_power_delivery_revision
> > 3.0
> >
> >  drivers/usb/typec/ucsi/ucsi.c | 25 +++++++++++++++++++++++++
> >  drivers/usb/typec/ucsi/ucsi.h |  3 +++
> >  2 files changed, 28 insertions(+)
> >
> > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> > index 4edf785d203b..8e0a512853ba 100644
> > --- a/drivers/usb/typec/ucsi/ucsi.c
> > +++ b/drivers/usb/typec/ucsi/ucsi.c
> > @@ -782,6 +782,8 @@ static int ucsi_register_partner(struct ucsi_connector *con)
> >         }
> >
> >         desc.usb_pd = pwr_opmode == UCSI_CONSTAT_PWR_OPMODE_PD;
> > +       desc.pd_revision =
> > +               UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags);
> >
> >         partner = typec_register_partner(con->port, &desc);
> >         if (IS_ERR(partner)) {
> > @@ -856,6 +858,28 @@ static void ucsi_partner_change(struct ucsi_connector *con)
> >                         con->num, u_role);
> >  }
> >
> > +static int ucsi_check_connector_capability(struct ucsi_connector *con)
> > +{
> > +       u64 command;
> > +       int ret;
> > +
> > +       if (!con->partner && !IS_MIN_VERSION_2_0(con->ucsi))
>
> (Mentioned side-band but reproducing here for consistency)
> This macro is unnecessary. It's just doing a comparison, which can be inlined
> without any perceptible change in readability (actually, I'd argue adding the !
> to an english idiom makes things *less* readable):

I prefer the macro because it makes it easier to search where version
checks are being done and it keeps the `<` vs `<=` consistent. UCSI
only has a few published revisions: 1.2, 2.0, 2.1 and 3.0 and major
changes seem to have happened in 2.0 and 3.0 so there should be very
few of these macros created/used.

>
>         if (!con->partner && con->ucsi->version < UCSI_VERSION_2_0)
>                return 0;
>
> Besides that, I think you want an || operator instead of the && operator, right?

Good catch on that. It should be OR.
i.e. if (!con->partner || !IS_MIN_VERSION_2_0(con->ucsi))

>
> > +               return 0;
> > +
> > +       command = UCSI_GET_CONNECTOR_CAPABILITY | UCSI_CONNECTOR_NUMBER(con->num);
> > +       ret = ucsi_send_command(con->ucsi, command, &con->cap, sizeof(con->cap));
> > +       if (ret < 0) {
> > +               dev_err(con->ucsi->dev, "GET_CONNECTOR_CAPABILITY failed (%d)\n", ret);
> > +               return ret;
> > +       }
> > +
> > +       typec_partner_set_pd_revision(
> > +               con->partner,
> > +               UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags));
> > +
> > +       return ret;
> > +}
> > +
> >  static int ucsi_check_connection(struct ucsi_connector *con)
> >  {
> >         u8 prev_flags = con->status.flags;
>
> Thanks,

Re: [PATCH v1 3/3] usb: typec: ucsi: Get PD revision for partner

[Prashant Malani]

On Wed, Jan 24, 2024 at 11:18 AM Abhishek Pandit-Subedi
<abhishekpandit@chromium.org> wrote:
>
> On Wed, Jan 24, 2024 at 10:49 AM Prashant Malani <pmalani@chromium.org> wrote:
> >
> > Hi Abhishek,
> >
> > On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
> > <abhishekpandit@google.com> wrote:
> > >
> > > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > >
> > > PD major revision for the port partner is described in
> > > GET_CONNECTOR_CAPABILITY and is only valid on UCSI 2.0 and newer. Update
> > > the pd_revision on the partner if the UCSI version is 2.0 or newer.
> > >
> > > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > > ---
> > > $ cat /sys/class/typec/port2-partner/usb_power_delivery_revision
> > > 3.0
> > >
> > >  drivers/usb/typec/ucsi/ucsi.c | 25 +++++++++++++++++++++++++
> > >  drivers/usb/typec/ucsi/ucsi.h |  3 +++
> > >  2 files changed, 28 insertions(+)
> > >
> > > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> > > index 4edf785d203b..8e0a512853ba 100644
> > > --- a/drivers/usb/typec/ucsi/ucsi.c
> > > +++ b/drivers/usb/typec/ucsi/ucsi.c
> > > @@ -782,6 +782,8 @@ static int ucsi_register_partner(struct ucsi_connector *con)
> > >         }
> > >
> > >         desc.usb_pd = pwr_opmode == UCSI_CONSTAT_PWR_OPMODE_PD;
> > > +       desc.pd_revision =
> > > +               UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags);
> > >
> > >         partner = typec_register_partner(con->port, &desc);
> > >         if (IS_ERR(partner)) {
> > > @@ -856,6 +858,28 @@ static void ucsi_partner_change(struct ucsi_connector *con)
> > >                         con->num, u_role);
> > >  }
> > >
> > > +static int ucsi_check_connector_capability(struct ucsi_connector *con)
> > > +{
> > > +       u64 command;
> > > +       int ret;
> > > +
> > > +       if (!con->partner && !IS_MIN_VERSION_2_0(con->ucsi))
> >
> > (Mentioned side-band but reproducing here for consistency)
> > This macro is unnecessary. It's just doing a comparison, which can be inlined
> > without any perceptible change in readability (actually, I'd argue adding the !
> > to an english idiom makes things *less* readable):
>
> I prefer the macro because it makes it easier to search where version
> checks are being done.

I don't see how searching for "IS_MIN_VERSION_2_0" is easier
than just searching for "UCSI_VERSION_2_0".

I didn't quite understand what you meant by

>  it keeps the `<` vs `<=` consistent.

Perhaps I'm missing something... (are these comparisons being
used elsewhere/in some other fashion?).

In any case, I don't want to bike-shed so I'll defer to the
maintainer's call on this.

BR,

-Prashant

Re: [PATCH v1 3/3] usb: typec: ucsi: Get PD revision for partner

[Abhishek Pandit-Subedi]

On Wed, Jan 24, 2024 at 11:34 AM Prashant Malani <pmalani@chromium.org> wrote:
>
> On Wed, Jan 24, 2024 at 11:18 AM Abhishek Pandit-Subedi
> <abhishekpandit@chromium.org> wrote:
> >
> > On Wed, Jan 24, 2024 at 10:49 AM Prashant Malani <pmalani@chromium.org> wrote:
> > >
> > > Hi Abhishek,
> > >
> > > On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
> > > <abhishekpandit@google.com> wrote:
> > > >
> > > > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > > >
> > > > PD major revision for the port partner is described in
> > > > GET_CONNECTOR_CAPABILITY and is only valid on UCSI 2.0 and newer. Update
> > > > the pd_revision on the partner if the UCSI version is 2.0 or newer.
> > > >
> > > > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > > > ---
> > > > $ cat /sys/class/typec/port2-partner/usb_power_delivery_revision
> > > > 3.0
> > > >
> > > >  drivers/usb/typec/ucsi/ucsi.c | 25 +++++++++++++++++++++++++
> > > >  drivers/usb/typec/ucsi/ucsi.h |  3 +++
> > > >  2 files changed, 28 insertions(+)
> > > >
> > > > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> > > > index 4edf785d203b..8e0a512853ba 100644
> > > > --- a/drivers/usb/typec/ucsi/ucsi.c
> > > > +++ b/drivers/usb/typec/ucsi/ucsi.c
> > > > @@ -782,6 +782,8 @@ static int ucsi_register_partner(struct ucsi_connector *con)
> > > >         }
> > > >
> > > >         desc.usb_pd = pwr_opmode == UCSI_CONSTAT_PWR_OPMODE_PD;
> > > > +       desc.pd_revision =
> > > > +               UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags);
> > > >
> > > >         partner = typec_register_partner(con->port, &desc);
> > > >         if (IS_ERR(partner)) {
> > > > @@ -856,6 +858,28 @@ static void ucsi_partner_change(struct ucsi_connector *con)
> > > >                         con->num, u_role);
> > > >  }
> > > >
> > > > +static int ucsi_check_connector_capability(struct ucsi_connector *con)
> > > > +{
> > > > +       u64 command;
> > > > +       int ret;
> > > > +
> > > > +       if (!con->partner && !IS_MIN_VERSION_2_0(con->ucsi))
> > >
> > > (Mentioned side-band but reproducing here for consistency)
> > > This macro is unnecessary. It's just doing a comparison, which can be inlined
> > > without any perceptible change in readability (actually, I'd argue adding the !
> > > to an english idiom makes things *less* readable):
> >
> > I prefer the macro because it makes it easier to search where version
> > checks are being done.
>
> I don't see how searching for "IS_MIN_VERSION_2_0" is easier
> than just searching for "UCSI_VERSION_2_0".
>
> I didn't quite understand what you meant by
>
> >  it keeps the `<` vs `<=` consistent.
>
> Perhaps I'm missing something... (are these comparisons being
> used elsewhere/in some other fashion?).

Let's say someone wants to guard code for UCSI 2.0.
Should they use:

// Guard against older versions.
if (ucsi->version < UCSI_VERSION_2_0) return;

// This also guards since the version jumps from 1.2 to 2.0.
if (ucsi->version <= UCSI_VERSION_1_2) return;

// Only do something on newer versions.
if (ucsi->version >= UCSI_VERSION_2_0) {
  // Fill out something available in newer spec.
}

I'd rather everyone just use a macro that normalizes comparisons. It's
always IS_MIN_VERSION and its inverse !IS_MIN_VERSION.
It's personal preference so deferring to the maintainer is IMO the
right call here.

>
> In any case, I don't want to bike-shed so I'll defer to the
> maintainer's call on this.
>
> BR,
>
> -Prashant

Re: [PATCH v1 1/3] usb: typec: ucsi: Limit read size on v1.2

[Greg Kroah-Hartman]

On Wed, Jan 24, 2024 at 10:59:28AM -0800, Abhishek Pandit-Subedi wrote:
> Ack. Will make dev_dbg on the next iteration.
> 
> This seems like a good addition to the style guide too:
> https://www.kernel.org/doc/html/v6.7/process/coding-style.html#printing-kernel-messages.
> "When drivers are working properly, they are quiet. Prefer to use
> DEBUG messages unless something is wrong."
> 
> What do you think Greg?

I think you need to stop top-posting :)

But yes, that would be nice, hopefully people actually notice it there.
Would you have read this and seen it?

thanks,

greg k-h

Re: [PATCH v1 1/3] usb: typec: ucsi: Limit read size on v1.2

[Abhishek Pandit-Subedi]

On Thu, Jan 25, 2024 at 3:16 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Wed, Jan 24, 2024 at 10:59:28AM -0800, Abhishek Pandit-Subedi wrote:
> > Ack. Will make dev_dbg on the next iteration.
> >
> > This seems like a good addition to the style guide too:
> > https://www.kernel.org/doc/html/v6.7/process/coding-style.html#printing-kernel-messages.
> > "When drivers are working properly, they are quiet. Prefer to use
> > DEBUG messages unless something is wrong."
> >
> > What do you think Greg?
>
> I think you need to stop top-posting :)
>
> But yes, that would be nice, hopefully people actually notice it there.
> Would you have read this and seen it?
>
> thanks,
>
> greg k-h

I blame gmail web-interface for the top-posting :)

Prashant also mentioned the dev_info when we were reviewing this so I
did a quick search for "kernel coding style" (to see if there was
guidance) before sending this up so I would definitely have noticed it
there.
In Bluetooth (where I've previously contributed), dev_info is used for
printing version info (example:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/bluetooth/btintel.c?h=v6.8-rc1#n337)
and it's very useful for debugging so I assumed it was acceptable.

The added benefit of this guidance being in the coding style guide is
it's a quick change to checkpatch.pl to add a warning for this (and
point to the coding style as the source). I'm fairly sure Chromium
actually has a lint that warns whenever you use LOG_INFO(...) for
similar reasons (too many INFO messages that should be DEBUG).

I will send up a patch with the change soon (both to coding style and
checkpatch.pl).

Thanks,
Abhishek