On 27/06/2024 18:25, Conor Dooley wrote: > On Thu, Jun 27, 2024 at 01:13:03PM +0200, Marc Gonzalez wrote: > >> TDP158 is an AC-coupled DVI / HDMI to TMDS level shifting Redriver. >> It supports DVI 1.0, HDMI 1.4b and 2.0b. >> It supports 4 TMDS channels, HPD, and a DDC interface. >> It supports dual power supply rails (1.1V on VDD, 3.3V on VCC) >> for power reduction. Several methods of power management are >> implemented to reduce overall power consumption. >> It supports fixed receiver EQ gain using I2C or pin strap to >> compensate for different lengths input cable or board traces. >> >> Features >> >> - AC-coupled TMDS or DisplayPort dual-mode physical layer input >> to HDMI 2.0b TMDS physical layer output supporting up to 6Gbps >> data rate, compatible with HDMI 2.0b electrical parameters >> - DisplayPort dual-mode standard version 1.1 >> - Programmable fixed receiver equalizer up to 15.5dB >> - Global or independent high speed lane control, pre-emphasis >> and transmit swing, and slew rate control >> - I2C or pin strap programmable >> - Configurable as a DisplayPort redriver through I2C >> - Full lane swap on main lanes >> - Low power consumption (200 mW at 6Gbps, 8 mW in shutdown) >> >> https://www.ti.com/lit/ds/symlink/tdp158.pdf >> >> Signed-off-by: Marc Gonzalez <mgonzalez@xxxxxxxxxx> >> --- >> .../bindings/display/bridge/ti,tdp158.yaml | 51 ++++++++++++++++++++++ >> 1 file changed, 51 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/display/bridge/ti,tdp158.yaml b/Documentation/devicetree/bindings/display/bridge/ti,tdp158.yaml >> new file mode 100644 >> index 0000000000000..21c8585c3bb2d >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/display/bridge/ti,tdp158.yaml >> @@ -0,0 +1,51 @@ >> +# SPDX-License-Identifier: GPL-2.0-only >> +%YAML 1.2 >> +--- >> +$id: http://devicetree.org/schemas/display/bridge/ti,tdp158.yaml# >> +$schema: http://devicetree.org/meta-schemas/core.yaml# >> + >> +title: TI TDP158 HDMI to TMDS Redriver >> + >> +maintainers: >> + - Arnaud Vrac <avrac@xxxxxxxxxx> >> + - Pierre-Hugues Husson <phhusson@xxxxxxxxxx> >> + >> +properties: >> + compatible: >> + const: ti,tdp158 >> + >> + reg: >> + description: I2C address of the device > > Is reg not required? How do you communicate with the device if the i2c > bus is not connected? Is the enable GPIO enough to operate it in some > situations? > > Otherwise this looks good to me, but given Maxime commented about the > complexity of the device, I'm probably out of my depth! Hello Conor, A cycle has been detected: Above, you defer to Maxime. Yet later, he wrote: "DT maintainers have required that reg is always present" I propose we NOT mark the "reg" property as required. (Thus, keep the binding as proposed in v3.) Rationale: - The device can be statically configured by pin straps, in which case it is NOT connected to an I2C bus. - Even if the device IS connected to an I2C bus, no I2C accesses are required if the default configuration meets the ODM's needs. Is that OK with you? Can I get your Amen? Regards
