diff mbox series

[v2,2/3] usb: typec: ucsi: Update connector cap and status

Message ID 20240124164443.v2.2.I3d909e3c9a200621e3034686f068a3307945fd87@changeid
State New
Headers show
Series usb: typec: ucsi: Adding support for UCSI 3.0 | expand

Commit Message

Abhishek Pandit-Subedi Jan. 25, 2024, 12:44 a.m. UTC 
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.


(no changes since v1)

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

Comments

Greg KH Jan. 26, 2024, 1:50 a.m. UTC | #1 
On Thu, Jan 25, 2024 at 04:21:47PM -0800, Abhishek Pandit-Subedi wrote:
> On Thu, Jan 25, 2024 at 3:03 PM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Wed, Jan 24, 2024 at 04:44:53PM -0800, Abhishek Pandit-Subedi wrote:
> > > 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>
> >
> > Do you really need to include a asm/ include file?  This feels very
> > wrong.
> 
> I didn't see any header in include/linux that already had these
> unaligned access functions so I opted to include
> asm-generic/unaligned.h. Is there a reason not to use an asm/ include
> file?

Yes, you should never need to include a asm/ file, unless you are
arch-specific code.

But the big issue is that you don't really need this, right?

> > It's also in the wrong place, AND why "asm-generic"?  That also feels
> > wrong.
> 
> asm-generic is definitely wrong; I misunderstood how these headers are
> supposed to be used (should be just asm/unaligned.h).

Why?  What are you requiring this .h file for?

> For ordering, I took a look at some other files and it looks like
> <asm/...> goes below the <linux/...> includes. This also probably
> deserves documenting in the style guide.

It is somewhere, checkpatch should complain about it.

thanks,

greg k-h
Greg KH Jan. 26, 2024, 6:30 p.m. UTC | #2 
On Fri, Jan 26, 2024 at 10:08:16AM -0800, Abhishek Pandit-Subedi wrote:
> On Thu, Jan 25, 2024 at 5:50 PM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Thu, Jan 25, 2024 at 04:21:47PM -0800, Abhishek Pandit-Subedi wrote:
> > > On Thu, Jan 25, 2024 at 3:03 PM Greg Kroah-Hartman
> > > <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > On Wed, Jan 24, 2024 at 04:44:53PM -0800, Abhishek Pandit-Subedi wrote:
> > > > > 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>
> > > >
> > > > Do you really need to include a asm/ include file?  This feels very
> > > > wrong.
> > >
> > > I didn't see any header in include/linux that already had these
> > > unaligned access functions so I opted to include
> > > asm-generic/unaligned.h. Is there a reason not to use an asm/ include
> > > file?
> >
> > Yes, you should never need to include a asm/ file, unless you are
> > arch-specific code.
> >
> > But the big issue is that you don't really need this, right?
> 
> The UCSI struct definitions have lots of unaligned bit ranges (and I
> will be refactoring <linux/bitfield.h> to support this but that's
> coming later). As an example, the GET_CONNECTOR_STATUS data structure
> has unaligned fields from bit 88-145.
> Rather than define my own macro, it was suggested I use the
> get_unaligned_le32 functions (see
> https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/5195032/3..4/drivers/usb/typec/ucsi/ucsi.h#b183).
> 
> I did a quick ripgrep on the drivers folder -- it looks like the "You
> should never need to include a asm/ file unless you are arch specific"
> isn't being followed for this file:
>   $ (cd drivers && rg -g '*.h' "unaligned\.h" -l) | wc -l
>   22
> 
> The unaligned access functions (get_unaligned_le16,
> get_unaligned_le32, etc) are really useful and widely used. Maybe they
> SHOULD be exposed from a <linux/unaligned.h> since they are so useful?
> I can send a follow-on patch that creates <linux/unaligned.h> (that
> simply just includes <asm/unaligned.h>) and moves all includes of
> <asm/unaligned.h> outside of "arch" to the linux header instead (this
> will also create a checkpatch warning now as you are expecting).

This is being worked on, see:
	https://lore.kernel.org/r/20231212024920.GG1674809@ZenIV

thanks,

greg k-h
Jameson Thies Feb. 8, 2024, 7:48 p.m. UTC | #3 
Hi Abhishek,

> +#define UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(_f_) \
> +       (UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV(_f_) << 8)

Can you replace this with a common HEADER_REV_AS_BCD macro that can be
used for both GET_CONNECTOR_CAPABILTY and GET_CABLE_PROPERTY?
Also, the USB PD major revision value in the message header is one less than the
revision (PD Spec section 6.2.1.1.5). So, we need to add 1 before shifting.

Thanks,
Jameson
Abhishek Pandit-Subedi Feb. 9, 2024, 4:35 a.m. UTC | #4 
On Thu, Feb 8, 2024 at 11:48 AM Jameson Thies <jthies@google.com> wrote:
>
> Hi Abhishek,
>
> > +#define UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(_f_) \
> > +       (UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV(_f_) << 8)
>
> Can you replace this with a common HEADER_REV_AS_BCD macro that can be
> used for both GET_CONNECTOR_CAPABILTY and GET_CABLE_PROPERTY?
> Also, the USB PD major revision value in the message header is one less than the
> revision (PD Spec section 6.2.1.1.5). So, we need to add 1 before shifting.

Jameson and I talked briefly and I discovered that PD assigns the
following values for the major rev:
* 00 = 1
* 01 = 2
* 10 = 3
* 11 = Reserved/Invalid
diff mbox series

Patch

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;
 
 /* -------------------------------------------------------------------------- */