gpt2 for pwm backlight on rzg2l custom board

we are trying to get GTIOC2B to be the PWM backlight provider. it is connected via P2_1. i am getting nothing out of the pin

i am using linux 5.10, cip41

here is my device tree set up. what am i doing wrong?

gpt2_pins: gpt2 {
pinmux =
<RZG2L_PORT_PINMUX(2, 1, 3)>; /* GTIOC2B */
};

&gpt2 {
pinctrl-0 = <&gpt2_pins>;
pinctrl-names = "default";
channel = "channel_B";

poeg = <&poega &poegb &poegc &poegd>;

status = "okay";
};

lcd_bl: backlight {
compatible = "pwm-backlight";
pwms = <&gpt2 0 1200>;
brightness-levels = <0 50 70 90 110 130 150 170 190 210 255>;
default-brightness-level = <10>;
power-supply = <&reg_3p3v>;
};

defconfig settings i assume apply:

CONFIG_PWM=y
CONFIG_PWM_RCAR=y
CONFIG_PWM_RZV2M=y
CONFIG_PWM_RENESAS_TPU=y
CONFIG_GPT_RZG2L=y
CONFIG_POEG_RZG2L=y