On Wed, Sep 26, 2018 at 04:23:52PM +0100, Adam Thomson wrote:
> When the controller is configured for a fixed power role (Source
> only or Sink only), attach does not proceed within the TCPM state
> machine as there is no CC event generated by this driver to update
> the CC line status.
>
> To rectify this, when CC is configured as Source or Sink we now
> make use of the hardware's automatic fixed Source or Sink
> toggling mechanism, which detects attaches in the same way as for
> DRP toggling. In this way the result of toggling is handled in the
> same way by the 'fusb302_handle_togdone()' function, and CC events
> are generated as expected for TCPM allowing a contract to be
> established.
>
> Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tcpm/fusb302.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/usb/typec/tcpm/fusb302.c b/drivers/usb/typec/tcpm/fusb302.c
> index fd851d8..43b64d9 100644
> --- a/drivers/usb/typec/tcpm/fusb302.c
> +++ b/drivers/usb/typec/tcpm/fusb302.c
> @@ -679,6 +679,7 @@ static int tcpm_set_cc(struct tcpc_dev *dev, enum typec_cc_status cc)
> int ret = 0;
> bool pull_up, pull_down;
> u8 rd_mda;
> + enum toggling_mode mode;
>
> mutex_lock(&chip->lock);
> switch (cc) {
> @@ -764,6 +765,29 @@ static int tcpm_set_cc(struct tcpc_dev *dev, enum typec_cc_status cc)
> chip->intr_comp_chng = false;
> }
> fusb302_log(chip, "cc := %s", typec_cc_status_name[cc]);
> +
> + /* Enable detection for fixed SNK or SRC only roles */
> + switch (cc) {
> + case TYPEC_CC_RD:
> + mode = TOGGLING_MODE_SNK;
> + break;
> + case TYPEC_CC_RP_DEF:
> + case TYPEC_CC_RP_1_5:
> + case TYPEC_CC_RP_3_0:
> + mode = TOGGLING_MODE_SRC;
> + break;
> + default:
> + mode = TOGGLING_MODE_OFF;
> + break;
> + }
> +
> + if (mode != TOGGLING_MODE_OFF) {
> + ret = fusb302_set_toggling(chip, mode);
> + if (ret < 0)
> + fusb302_log(chip,
> + "cannot set fixed role toggling mode, ret=%d",
> + ret);
> + }
> done:
> mutex_unlock(&chip->lock);
>
> --
> 1.9.1
--
heikki
