Re: [PATCH v1 7/7] arm: dts: rockchip: rk3288: partial sync pwm nodes

15 Mar 2023

On 3/15/23 15:05, Simon Glass wrote:
...
Hi Johan,
On Tue, 14 Mar 2023 at 12:16, Johan Jonker jbx6244@gmail.com wrote:
...
In order to better compare the Linux rk3288.dtsi
version 6.3 -rc2 with the u-boot version partial
sync the pwm nodes.
Signed-off-by: Johan Jonker jbx6244@gmail.com
arch/arm/dts/rk3288.dtsi | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/arch/arm/dts/rk3288.dtsi b/arch/arm/dts/rk3288.dtsi
index f24e9ba5..dd1d9897 100644
--- a/arch/arm/dts/rk3288.dtsi
+++ b/arch/arm/dts/rk3288.dtsi
@@ -675,9 +675,7 @@
                #pwm-cells = <3>;
                pinctrl-names = "default";
                pinctrl-0 = <&pwm0_pin>;

          clocks = <&cru PCLK_PWM>;


          clock-names = "pwm";


          rockchip,grf = <&grf>;




          clocks = <&cru PCLK_RKPWM>;
          status = "disabled";
  };




@@ -687,9 +685,7 @@
                #pwm-cells = <3>;
                pinctrl-names = "default";
                pinctrl-0 = <&pwm1_pin>;

          clocks = <&cru PCLK_PWM>;


          clock-names = "pwm";


          rockchip,grf = <&grf>;




          clocks = <&cru PCLK_RKPWM>;
          status = "disabled";
  };




@@ -699,21 +695,17 @@
                #pwm-cells = <3>;
                pinctrl-names = "default";
                pinctrl-0 = <&pwm2_pin>;

          clocks = <&cru PCLK_PWM>;


          clock-names = "pwm";


          rockchip,grf = <&grf>;




          clocks = <&cru PCLK_RKPWM>;
          status = "disabled";
  };

  pwm3: pwm@ff680030 {
          compatible = "rockchip,rk3288-pwm";
          reg = <0xff680030 0x10>;




          #pwm-cells = <2>;




          #pwm-cells = <3>;



...
How can we do this without breaking the existing pwm usage in U-Boot?
===
...
From binding pwm-rockchip.yaml:
"#pwm-cells":
    enum: [2, 3]
    description:
      Must be 2 (rk2928) or 3 (rk3288 and later).
      See pwm.yaml for a description of the cell format.
===
...
From binding pwm.txt:
pwm-specifier typically encodes the chip-relative PWM number and the PWM
period in nanoseconds.
Optionally, the pwm-specifier can encode a number of flags (defined in
<dt-bindings/pwm/pwm.h>) in a third cell:
- PWM_POLARITY_INVERTED: invert the PWM signal polarity
===
Fixed with patch:
[PATCH] ARM: dts: rockchip: fix pwm-cells for rk3288's pwm3
https://lore.kernel.org/all/20190603143435.23352-1-john@metanate.com/
===
U-Boot driver is ready:
static const struct rockchip_pwm_data pwm_data_v2 = {
[..]
    .supports_polarity = true,
[..]
};
{ .compatible = "rockchip,rk3288-pwm", .data = (ulong)&pwm_data_v2},
===
git grep "pwms = <&pwm" | grep rk3288
rk3288-evb.dtsi:		pwms = <&pwm0 0 25000 0>;
rk3288-veyron.dtsi:		pwms = <&pwm0 0 1000000 0>;
rk3288-veyron.dtsi:		pwms = <&pwm1 0 2000 0>;
Given that there are no current users and the driver supports polarity I think it's save to set #pwm-cells to 3.
(Unless someone calls out a specific case not to change)
Johan
...
...
            pinctrl-names = "default";
            pinctrl-0 = <&pwm3_pin>;


          clocks = <&cru PCLK_PWM>;


          clock-names = "pwm";


          rockchip,grf = <&grf>;




          clocks = <&cru PCLK_RKPWM>;
          status = "disabled";
  };




--
2.20.1
Regards,
Simon

    