Hi Guenter, Am 20.01.20 um 21:26 schrieb Guenter Roeck: > On 1/20/20 12:14 PM, Markus Reichl wrote: >> Hi Guenter, >> >> Am 20.01.20 um 17:04 schrieb Guenter Roeck: >>> On 1/20/20 6:34 AM, Markus Reichl wrote: >>>> Hi Guenter, >>>> >>>> Am 20.01.20 um 15:21 schrieb Guenter Roeck: >>>>> On 1/20/20 3:58 AM, Heikki Krogerus wrote: >>>>>> Hi Markus, >>>>>> >>>>>> On Thu, Jan 09, 2020 at 05:29:07PM +0100, Markus Reichl wrote: >>>>>>> Hi, >>>>>>> >>>>>>> I'm working with a ROC-RK3399-PC arm64 board from firefly, circuit sheet [1]. >>>>>>> The board is powered from an USB-C type connector via an FUSB302 PD controller. >>>>>>> With measured 15W+ power consumption it should use higher voltage PD modes than >>>>>>> the standard 5V USB-C mode. >>>>>>> >>>>>>> When I add the related connector node in DTS [2] the FUSB302 initializes >>>>>>> the right PD mode (e.g. 15V/3A). >>>>>>> >>>>>>> But during initialisation the PD is switched off shortly and the board has a blackout. >>>>>>> When I inject a backup supply voltage behind the FUSB302 (e.g. at SYS_12V line) during boot >>>>>>> I can remove the backup after succesfull setting up the PD and the board will run fine. >>>>>>> >>>>>>> Is it possible to change the behaviour of the fusb302 driver to not power down the PD supply >>>>>>> during init? >>>>>> >>>>>> I guess it's also possible that the problem is with tcpm.c instead of >>>>>> fusb302.c. tcpm.c provides the USB PD state matchines. Guenter! Can >>>>>> you take a look at this? >>>>>> >>>>> >>>>> There was always a problem with handoff from the bootloader. tcpm_init() calls >>>>> tcpm_reset_port() which turns vbus and vconn off, which I imagine can >>>>> trigger the situation. >>>>> >>>>> Unfortunately I was never able to solve the puzzle. The Type-C protocol does >>>>> not support any kind of "hand-off" from one component in the system to another. >>>>> If the state machine doesn't start from a clean state, there is pretty >>>>> much no guarantee that it ever synchronizes. >>>>> >>>>> Maybe someone can find a better solution, but when I wrote the code I just >>>>> could not get it to work reliably without resetting everything during >>>>> registration. >>>>> >>>>> Note that v4.4 did not include the upstream tcpm code, suggesting the >>>>> code in the vendor kernel was possibly using a different or backported >>>>> state machine. Impossible to say what was done there without access >>>>> to the code. >>>> >>>> The vendor code for fusb302 is here: >>>> https://github.com/FireflyTeam/kernel/tree/rk3399/firefly/drivers/mfd >>>> >>> >>> AFAICS the vendor code don't reset VBUS, and selectively (only) resets the >>> PD state machine in the fusb302 on startup. The tcpm state machine is embedded >>> in the fusb302 driver, making this easier to control. >>> >>> The fusb302 Linux kernel driver, on the other side, resets the entire fusb302 >>> on initialization, not just PD (bit 0 of the reset register). Question is if >>> that can be changed to just reset PD (bit 1 of the reset register). >>> Maybe that would already fix the problem. Can you give it a try ? >>> >>> Guenter >> >> I tried >> >> diff --git a/drivers/usb/typec/tcpm/fusb302.c b/drivers/usb/typec/tcpm/fusb302.c >> index ed8655c6af8c..6e15e7b22064 100644 >> --- a/drivers/usb/typec/tcpm/fusb302.c >> +++ b/drivers/usb/typec/tcpm/fusb302.c >> @@ -334,11 +334,11 @@ static int fusb302_sw_reset(struct fusb302_chip *chip) >> int ret = 0; >> ret = fusb302_i2c_write(chip, FUSB_REG_RESET, >> - FUSB_REG_RESET_SW_RESET); >> + FUSB_REG_RESET_PD_RESET); >> if (ret < 0) >> - fusb302_log(chip, "cannot sw reset the chip, ret=%d", ret); >> + fusb302_log(chip, "cannot pd reset the chip, ret=%d", ret); >> else >> - fusb302_log(chip, "sw reset"); >> + fusb302_log(chip, "pd reset"); >> return ret; >> } >> >> but did not help, after mmc and ehci initializing the PD-supply gets switched off at 1.95s. > > Next step to try would be to skip vbus initialization - drop tcpm_init_vbus() > from tcpm_reset_port(). Can you do that as well ? diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index f3087ef8265c..db2a75d67bc7 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -2698,7 +2698,7 @@ static void tcpm_reset_port(struct tcpm_port *port) port->rx_msgid = -1; port->tcpc->set_pd_rx(port->tcpc, false); - tcpm_init_vbus(port); /* also disables charging */ +// tcpm_init_vbus(port); /* also disables charging */ tcpm_init_vconn(port); tcpm_set_current_limit(port, 0, 0); tcpm_set_polarity(port, TYPEC_POLARITY_CC1); Did not help, but instead of switching off, reboots now most of the time. I watch with an USB-C-Power meter (V and A). > > Thanks, > Guenter
