[PATCH v4 0/3] usb: typec: ucsi: Adding support for UCSI 3.0

[PATCH v4 0/3] usb: typec: ucsi: Adding support for UCSI 3.0

[Abhishek Pandit-Subedi]

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

Changes in v4:
  - Added missing Tested-By tags from v1 and reviewed-by tags.
  - Fix BCD translation of PD Major Rev
  - Replace IS_MIN_VERSION macro and just compare version directly.

Changes in v3:
  - Change include to asm/unaligned.h and reorder include.

Changes in v2:
  - Changed log message to DEBUG
  - Formatting changes and update macro to use brackets.
  - Fix incorrect guard condition when checking connector capability.

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 | 49 +++++++++++++++++++++++--
 drivers/usb/typec/ucsi/ucsi.h | 67 ++++++++++++++++++++++++++++++++---
 2 files changed, 110 insertions(+), 6 deletions(-)

-- 
2.43.0.687.g38aa6559b0-goog

[PATCH v4 1/3] usb: typec: ucsi: Limit read size on v1.2

[Abhishek Pandit-Subedi]

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.

Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
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


Changes in v4:
  - Added missing Tested-By tags from v1 and reviewed-by tags.

Changes in v2:
  - Changed log message to DEBUG

 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 14f5a7bfae2e..d9a345ec62c3 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;
 	}
@@ -1558,6 +1571,15 @@ 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_dbg(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)
-- 
2.43.0.687.g38aa6559b0-goog

Re: [PATCH v4 1/3] usb: typec: ucsi: Limit read size on v1.2

[Andy Shevchenko]

On Thu, Feb 08, 2024 at 10:02:38PM -0800, Abhishek Pandit-Subedi wrote:
> 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.

...

> +	if (ucsi->version <= UCSI_VERSION_1_2)
> +		buf_size = min_t(size_t, 16, buf_size);

Please, avoid using min_t(). Here the clamp() can be used.
Shouldn't magic number be defined?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 1/3] usb: typec: ucsi: Limit read size on v1.2

[Abhishek Pandit-Subedi]

On Fri, Feb 9, 2024 at 6:28 AM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Thu, Feb 08, 2024 at 10:02:38PM -0800, Abhishek Pandit-Subedi wrote:
> > 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.
>
> ...
>
> > +     if (ucsi->version <= UCSI_VERSION_1_2)
> > +             buf_size = min_t(size_t, 16, buf_size);
>
> Please, avoid using min_t(). Here the clamp() can be used.
I think this is likely the 4th time I've been tripped up by an
undocumented practice in this patch series. <linux/minmax.h> says
nothing about avoiding min_t -- why prefer clamp()? Please add the
recommendation here
(https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/minmax.h#n10)
and I am more than happy to change it after.

> Shouldn't magic number be defined?
The comment right above this line documents the number.
As this is the only use right now, I don't see a need to make it a
macro/constant yet.

>
> --
> With Best Regards,
> Andy Shevchenko
>
>

Cheers,
Abhishek

Re: [PATCH v4 1/3] usb: typec: ucsi: Limit read size on v1.2

[Andy Shevchenko]

On Fri, Feb 09, 2024 at 10:01:07AM -0800, Abhishek Pandit-Subedi wrote:
> On Fri, Feb 9, 2024 at 6:28 AM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > On Thu, Feb 08, 2024 at 10:02:38PM -0800, Abhishek Pandit-Subedi wrote:

...

> > > +     if (ucsi->version <= UCSI_VERSION_1_2)
> > > +             buf_size = min_t(size_t, 16, buf_size);
> >
> > Please, avoid using min_t(). Here the clamp() can be used.
> I think this is likely the 4th time I've been tripped up by an
> undocumented practice in this patch series. <linux/minmax.h> says
> nothing about avoiding min_t -- why prefer clamp()?

While in this case it will work correctly, the size_t is unsigned type and 16
is signed, while buf_size is unknown in this context. It means if buf_size is
signed, the min_t gives wrong result. clamp() is better choice.

See also, e.g., https://lore.kernel.org/all/20231004064220.31452-1-biju.das.jz@bp.renesas.com/.

> Please add the
> recommendation here
> (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/minmax.h#n10)
> and I am more than happy to change it after.

It's not my recommendation :-)

https://lore.kernel.org/all/CAHk-=whwEAc22wm8h9FESPB5X+P4bLDgv0erBQMa1buTNQW7tA@mail.gmail.com/

Feel free to submit a patch.

...

> > Shouldn't magic number be defined?
> The comment right above this line documents the number.
> As this is the only use right now, I don't see a need to make it a
> macro/constant yet.

OK.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 1/3] usb: typec: ucsi: Limit read size on v1.2

[Abhishek Pandit-Subedi]

On Fri, Feb 9, 2024 at 11:39 AM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Fri, Feb 09, 2024 at 10:01:07AM -0800, Abhishek Pandit-Subedi wrote:
> > On Fri, Feb 9, 2024 at 6:28 AM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > On Thu, Feb 08, 2024 at 10:02:38PM -0800, Abhishek Pandit-Subedi wrote:
>
> ...
>
> > > > +     if (ucsi->version <= UCSI_VERSION_1_2)
> > > > +             buf_size = min_t(size_t, 16, buf_size);
> > >
> > > Please, avoid using min_t(). Here the clamp() can be used.
> > I think this is likely the 4th time I've been tripped up by an
> > undocumented practice in this patch series. <linux/minmax.h> says
> > nothing about avoiding min_t -- why prefer clamp()?
>
> While in this case it will work correctly, the size_t is unsigned type and 16
> is signed, while buf_size is unknown in this context. It means if buf_size is
> signed, the min_t gives wrong result. clamp() is better choice.
>
> See also, e.g., https://lore.kernel.org/all/20231004064220.31452-1-biju.das.jz@bp.renesas.com/.
>
> > Please add the
> > recommendation here
> > (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/minmax.h#n10)
> > and I am more than happy to change it after.
>
> It's not my recommendation :-)
>
> https://lore.kernel.org/all/CAHk-=whwEAc22wm8h9FESPB5X+P4bLDgv0erBQMa1buTNQW7tA@mail.gmail.com/
>
> Feel free to submit a patch.
>

Ack, will send up a PATCH v5. And add to my backlog of foot-gun
checkpatch and docs fixes I need to send up :)

> ...
>
> > > Shouldn't magic number be defined?
> > The comment right above this line documents the number.
> > As this is the only use right now, I don't see a need to make it a
> > macro/constant yet.
>
> OK.
>
> --
> With Best Regards,
> Andy Shevchenko
>
>

[PATCH v4 2/3] usb: typec: ucsi: Update connector cap and status

[Abhishek Pandit-Subedi]

Update the data structures for ucsi_connector_capability and
ucsi_connector_status to UCSIv3.

Reviewed-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v4:
  - Fix BCD translation of PD Major Rev

Changes in v3:
  - Change include to asm/unaligned.h and reorder include.

 drivers/usb/typec/ucsi/ucsi.h | 56 ++++++++++++++++++++++++++++++++---
 1 file changed, 52 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index bec920fa6b8a..7e35ffbe0a6f 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -10,6 +10,7 @@
 #include <linux/usb/typec.h>
 #include <linux/usb/pd.h>
 #include <linux/usb/role.h>
+#include <asm/unaligned.h>
 
 /* -------------------------------------------------------------------------- */
 
@@ -35,6 +36,12 @@ struct dentry;
 #define UCSI_BCD_GET_MINOR(_v_)		(((_v_) >> 4) & 0x0F)
 #define UCSI_BCD_GET_SUBMINOR(_v_)	((_v_) & 0x0F)
 
+/*
+ * Per USB PD 3.2, Section 6.2.1.1.5, the spec revision is represented by 2 bits
+ * 0b00 = 1.0, 0b01 = 2.0, 0b10 = 3.0, 0b11 = Reserved, Shall NOT be used.
+ */
+#define UCSI_SPEC_REVISION_TO_BCD(_v_)  (((_v_) + 1) << 8)
+
 /* 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)
@@ -214,9 +221,29 @@ 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_SPEC_REVISION_TO_BCD(UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV(_f_))
 } __packed;
 
 struct ucsi_altmode {
@@ -276,15 +303,36 @@ 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;
 
 /* -------------------------------------------------------------------------- */
-- 
2.43.0.687.g38aa6559b0-goog

[PATCH v4 3/3] usb: typec: ucsi: Get PD revision for partner

[Abhishek Pandit-Subedi]

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.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---
$ cat /sys/class/typec/port2-partner/usb_power_delivery_revision
3.0

Changes in v4:
  - Replace IS_MIN_VERSION macro and just compare version directly.

Changes in v2:
  - Formatting changes and update macro to use brackets.
  - Fix incorrect guard condition when checking connector capability.

 drivers/usb/typec/ucsi/ucsi.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index d9a345ec62c3..9d49dbeee9d5 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -782,6 +782,7 @@ 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 +857,27 @@ 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 || con->ucsi->version < UCSI_VERSION_2_0)
+		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 +947,7 @@ 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)
-- 
2.43.0.687.g38aa6559b0-goog