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. Gruß, Markus _______________________________________________ Linux-rockchip mailing list Linux-rockchip@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-rockchip
