Commit 19c234a1 authored by Badhri Jagan Sridharan's avatar Badhri Jagan Sridharan Committed by Greg Kroah-Hartman
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usb: typec: tcpci: Check ROLE_CONTROL while interpreting CC_STATUS 



While interpreting CC_STATUS, ROLE_CONTROL has to be read to make
sure that CC1/CC2 is not forced presenting Rp/Rd.

>From the TCPCI spec:

4.4.5.2 ROLE_CONTROL (Normative):
The TCPM shall write B6 (DRP) = 0b and B3..0 (CC1/CC2) if it wishes
to control the Rp/Rd directly instead of having the TCPC perform
DRP toggling autonomously. When controlling Rp/Rd directly, the
TCPM writes to B3..0 (CC1/CC2) each time it wishes to change the
CC1/CC2 values. This control is used for TCPM-TCPC implementing
Source or Sink only as well as when a connection has been detected
via DRP toggling but the TCPM wishes to attempt Try.Src or Try.Snk.

Table 4-22. CC_STATUS Register Definition:
If (ROLE_CONTROL.CC1 = Rd) or ConnectResult=1)
00b: SNK.Open (Below maximum vRa)
01b: SNK.Default (Above minimum vRd-Connect)
10b: SNK.Power1.5 (Above minimum vRd-Connect) Detects Rp-1.5A
11b: SNK.Power3.0 (Above minimum vRd-Connect) Detects Rp-3.0A

If (ROLE_CONTROL.CC2=Rd) or (ConnectResult=1)
00b: SNK.Open (Below maximum vRa)
01b: SNK.Default (Above minimum vRd-Connect)
10b: SNK.Power1.5 (Above minimum vRd-Connect) Detects Rp 1.5A
11b: SNK.Power3.0 (Above minimum vRd-Connect) Detects Rp 3.0A

Fixes: 74e656d6 ("staging: typec: Type-C Port Controller Interface driver (tcpci)")
Acked-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: default avatarBadhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20210304070931.1947316-1-badhri@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 365038f2

drivers/usb/typec/tcpm/tcpci.c

+18 −3
Original line number Diff line number Diff line
@@ -24,6 +24,15 @@ 
#define	AUTO_DISCHARGE_PD_HEADROOM_MV		850

#define	AUTO_DISCHARGE_PPS_HEADROOM_MV		1250



#define tcpc_presenting_cc1_rd(reg) \

	(!(TCPC_ROLE_CTRL_DRP & (reg)) && \

	 (((reg) & (TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT)) == \

	  (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT)))

#define tcpc_presenting_cc2_rd(reg) \

	(!(TCPC_ROLE_CTRL_DRP & (reg)) && \

	 (((reg) & (TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT)) == \

	  (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT)))



struct tcpci {

	struct device *dev;
@@ -178,19 +187,25 @@ static int tcpci_get_cc(struct tcpc_dev *tcpc, 
			enum typec_cc_status *cc1, enum typec_cc_status *cc2)

{

	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);

	unsigned int reg;

	unsigned int reg, role_control;

	int ret;



	ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &role_control);

	if (ret < 0)

		return ret;



	ret = regmap_read(tcpci->regmap, TCPC_CC_STATUS, &reg);

	if (ret < 0)

		return ret;



	*cc1 = tcpci_to_typec_cc((reg >> TCPC_CC_STATUS_CC1_SHIFT) &

				 TCPC_CC_STATUS_CC1_MASK,

				 reg & TCPC_CC_STATUS_TERM);

				 reg & TCPC_CC_STATUS_TERM ||

				 tcpc_presenting_cc1_rd(role_control));

	*cc2 = tcpci_to_typec_cc((reg >> TCPC_CC_STATUS_CC2_SHIFT) &

				 TCPC_CC_STATUS_CC2_MASK,

				 reg & TCPC_CC_STATUS_TERM);

				 reg & TCPC_CC_STATUS_TERM ||

				 tcpc_presenting_cc2_rd(role_control));



	return 0;

}