Re: [PATCH v11 6/9] drm/bridge: anx7625: Register Type C mode switches

From: Nícolas F. R. A. Prado
Date: Fri Feb 17 2023 - 10:32:05 EST


On Sat, Feb 04, 2023 at 09:30:37PM +0800, Pin-yen Lin wrote:
[..]
> --- a/drivers/gpu/drm/bridge/analogix/anx7625.c
> +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
[..]
> +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);

This seems inverted compared to the binding. Binding says

0, 1, 2, 3 in "data-lanes" maps to SSRX1, SSTX1, SSRX2, SSTX2, respectively.

But in anx7625_register_typec_switches(), lanes 0-1 mean orientation normal,
then in this logic, you set RX2 and TX2 to carry the DP signals. So the driver
is mapping lanes 0-1 to SSRX2/SSTX2 and lanes 2-3 to SSRX1/SSTX1, the opposite
from the binding.

Thanks,
Nícolas

> + } 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 int anx7625_register_typec_switches(struct device *dev, struct anx7625_data *ctx)
> +{
[..]
> + ctx->port_data[i].orientation = (dp_lanes[0] / 2 == 0) ?
> + TYPEC_ORIENTATION_NORMAL : TYPEC_ORIENTATION_REVERSE;
[..]