title: defining 3 regulators controlled by same GPIO pin in linux devicetree (arm)
body: <p>I have a board for which I'm fixing/writing the device tree for, based on the rk3288 (rockchip). In the file there are currently the following definitions for three seperate regulators: </p>
  
  <pre><code>    dovdd_1v8: dovdd-1v8-regulator {
              compatible = "regulator-fixed";
              enable-active-high;
              gpio = &lt;&amp;gpio0 11 GPIO_ACTIVE_HIGH&gt;;
              pinctrl-names = "default";
              pinctrl-0 = &lt;&amp;dvp_pwr&gt;;
              regulator-name = "dovdd_1v8";
              regulator-min-microvolt = &lt;1800000&gt;;
              regulator-max-microvolt = &lt;1800000&gt;;
              vin-supply = &lt;&amp;vcc_io&gt;;
      };
  
      vcc28_dvp: vcc28-dvp-regulator {
              compatible = "regulator-fixed";
              enable-active-high;
              gpio = &lt;&amp;gpio0 11 GPIO_ACTIVE_HIGH&gt;;
              pinctrl-names = "default";
              pinctrl-0 = &lt;&amp;dvp_pwr&gt;;
              regulator-name = "vcc28_dvp";
              regulator-min-microvolt = &lt;2800000&gt;;
              regulator-max-microvolt = &lt;2800000&gt;;
              vin-supply = &lt;&amp;vcc_io&gt;;
      };
  
      af_28: af_28-regulator {
              compatible = "regulator-fixed";
              enable-active-high;
              gpio = &lt;&amp;gpio0 11 GPIO_ACTIVE_HIGH&gt;;
              pinctrl-names = "default";
              pinctrl-0 = &lt;&amp;dvp_pwr&gt;;
              regulator-name = "af_28";
              regulator-min-microvolt = &lt;2800000&gt;;
              regulator-max-microvolt = &lt;2800000&gt;;
              vin-supply = &lt;&amp;vcc_io&gt;;
      };
  </code></pre>
  
  <p>The problem is that the kernel complains that it can't assign the same GPIO pin to these 3 regulators. In the schematic for the board the regulators are controlled by the same GPIO pin. </p>
  
  <p>What is the right way to do this? </p>
  
  <p>Thanks!
  B</p>
  
  <p>EDIT: here is the error message I see on the serial console: </p>
  
  <pre><code>[    0.270507] rockchip-pinctrl pinctrl: pin gpio0-11 already requested 
  by dovdd-1v8-regulator; cannot claim for vcc28-dvp-regulator
  [    0.270570] rockchip-pinctrl pinctrl: pin-11 (vcc28-dvp-regulator) status -22
  [    0.270611] rockchip-pinctrl pinctrl: could not request pin 11 (gpio0-11) from group dvp-pwr  on device rockchip-pinctrl
  [    0.270663] reg-fixed-voltage vcc28-dvp-regulator: Error applying setting, reverse things back
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/qUSmg.png" rel="nofollow"><img src="https://i.stack.imgur.com/qUSmg.png" alt="cif power regulators"></a></p>