On Tue, Jun 14, 2022 at 2:08 AM Pin-yen Lin <treapking@xxxxxxxxxxxx> wrote:
>
> Hi AngeloGioacchino,
>
>
> On Tue, Jun 14, 2022 at 4:15 PM AngeloGioacchino Del Regno
> <angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:
> >
> > Il 09/06/22 20:09, Prashant Malani ha scritto:
> > > From: Pin-Yen Lin <treapking@xxxxxxxxxxxx>
> > >
> > > Add the callback function when the driver receives state
> > > changes of the Type-C port. The callback function configures the
> > > crosspoint switch of the anx7625 bridge chip, which can change the
> > > output pins of the signals according to the port state.
> > >
> > > Signed-off-by: Pin-Yen Lin <treapking@xxxxxxxxxxxx>
> > > Signed-off-by: Prashant Malani <pmalani@xxxxxxxxxxxx>
> > > ---
> > >
> > > Changes since v2:
> > > - No changes.
> > >
> > > drivers/gpu/drm/bridge/analogix/anx7625.c | 58 +++++++++++++++++++++++
> > > drivers/gpu/drm/bridge/analogix/anx7625.h | 13 +++++
> > > 2 files changed, 71 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
> > > index d41a21103bd3..2c308d12fab2 100644
> > > --- a/drivers/gpu/drm/bridge/analogix/anx7625.c
> > > +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
> > > @@ -15,6 +15,7 @@
> > > #include <linux/regulator/consumer.h>
> > > #include <linux/slab.h>
> > > #include <linux/types.h>
> > > +#include <linux/usb/typec_dp.h>
> > > #include <linux/usb/typec_mux.h>
> > > #include <linux/workqueue.h>
> > >
> > > @@ -2582,9 +2583,66 @@ static void anx7625_runtime_disable(void *data)
> > > pm_runtime_disable(data);
> > > }
> > >
> > > +static void anx7625_set_crosspoint_switch(struct anx7625_data *ctx,
> > > + enum typec_orientation orientation)
> > > +{
> > > + if (orientation == TYPEC_ORIENTATION_NORMAL) {
> > > + anx7625_reg_write(ctx, ctx->i2c.tcpc_client, TCPC_SWITCH_0,
> > > + SW_SEL1_SSRX_RX1 | SW_SEL1_DPTX0_RX2);
> > > + anx7625_reg_write(ctx, ctx->i2c.tcpc_client, TCPC_SWITCH_1,
> > > + SW_SEL2_SSTX_TX1 | SW_SEL2_DPTX1_TX2);
> > > + } else if (orientation == TYPEC_ORIENTATION_REVERSE) {
> > > + anx7625_reg_write(ctx, ctx->i2c.tcpc_client, TCPC_SWITCH_0,
> > > + SW_SEL1_SSRX_RX2 | SW_SEL1_DPTX0_RX1);
> > > + anx7625_reg_write(ctx, ctx->i2c.tcpc_client, TCPC_SWITCH_1,
> > > + SW_SEL2_SSTX_TX2 | SW_SEL2_DPTX1_TX1);
> > > + }
> > > +}
> > > +
> > > +static void anx7625_typec_two_ports_update(struct anx7625_data *ctx)
> > > +{
> > > + if (ctx->typec_ports[0].dp_connected && ctx->typec_ports[1].dp_connected)
> > > + /* Both ports available, do nothing to retain the current one. */
> > > + return;
> > > + else if (ctx->typec_ports[0].dp_connected)
> > > + anx7625_set_crosspoint_switch(ctx, TYPEC_ORIENTATION_NORMAL);
> > > + else if (ctx->typec_ports[1].dp_connected)
> > > + anx7625_set_crosspoint_switch(ctx, TYPEC_ORIENTATION_REVERSE);
> > > +}
> > > +
> > > static int anx7625_typec_mux_set(struct typec_mux_dev *mux,
> > > struct typec_mux_state *state)
> > > {
> > > + struct anx7625_port_data *data = typec_mux_get_drvdata(mux);
> > > + struct anx7625_data *ctx = data->ctx;
> > > + struct device *dev = &ctx->client->dev;
> > > +
> > > + bool old_dp_connected = (ctx->typec_ports[0].dp_connected ||
> > > + ctx->typec_ports[1].dp_connected);
> >
> > So the old connection state is "either port0 or port1 are currently connected"...
> >
> > > + bool new_dp_connected;
> > > +
> > > + if (ctx->num_typec_switches == 1)
> > > + return 0;
> > > +
> > > + dev_dbg(dev, "mux_set dp_connected: c0=%d, c1=%d\n",
> > > + ctx->typec_ports[0].dp_connected, ctx->typec_ports[1].dp_connected);
> > > +
> > > + data->dp_connected = (state->alt && state->alt->svid == USB_TYPEC_DP_SID &&
> > > + state->alt->mode == USB_TYPEC_DP_MODE);
> > > + > + new_dp_connected = (ctx->typec_ports[0].dp_connected ||
> > > + ctx->typec_ports[1].dp_connected);
> >
> > ...and the new connection state is the same as the old one, because I don't see
> > anything that could ever modify it in this function's flow, until reaching this
> > assignment.
>
> The typec mux driver data (`struct anx7625_port_data *data =
> typec_mux_get_drvdata(mux)`) is set to one of the
> `ctx->typec_ports[*]` in `anx7625_register_mode_switch` (see patch 6
> of this series).
>
> So, the `data->dp_connected = ...` assignment may change the new
> connection state.
Angelo, I think your interpretation of this logic is not accurate..
|old_dp_connected| represents *whether* port1 or port0 has a DP
partner connected, not that *either* of them has it.
So, this logic looks OK to me.
>
> Best regards,
> Pin-yen
>
> >
> > > +
> > > + /* dp on, power on first */
> > > + if (!old_dp_connected && new_dp_connected)
> > > + pm_runtime_get_sync(dev);
> >
> > ...so that will never happen...
> >
> > > +
> > > + anx7625_typec_two_ports_update(ctx);
> > > +
> > > + /* dp off, power off last */
> > > + if (old_dp_connected && !new_dp_connected)
> > > + pm_runtime_put_sync(dev);
> >
> > ...and same here.
> >
> > Regards,
> > Angelo
