- dcdc-en-gpios: power IC supply enable

i cannot make this as gpios, since pm8921_lvs7 is a regulator.
We can make gpio as regulator, but not regulator as gpio.

other option i have to map pm8921_lvs7 to iovcc-supply and pm8921_gpio
23 to dcdc-en-gpios.

Since we do not have nx7 schematic not sure which pins are mapped in
hardware, other than the src code reference. Even in the 3.4 source
code gpio/pin/regulator mappings and naming are not proper in
board-flo-display.c

What is your suggestion?

On Wed, Aug 24, 2016 at 6:02 PM, Thierry Reding
[off-list ref] wrote:

On Wed, Aug 24, 2016 at 05:34:55PM +0530, Vinay Simha wrote:

quoted

thierry,

this is the reference pinouts of the panel
http://www.tonylabs.com/wp-content/uploads/LT070ME05000-pinouts.jpg

I can't open that file.

quoted

as you suggest , i will change the vcc-supply,

 - iovcc-supply: phandle of the regulator that supplies power to
          the IOVCC voltage input (1.8 V)

will keep the other two(vddp-supply, dcdc_en-supply) remaining same.

"dcdc_en" sounds to me like it should be a GPIO rather than a regulator.

According to this datasheet:

        http://kb.52solution.com/data/uploads/2016/04/07/3172846545705cc22d050e.pdf

the input voltages are indeed VDD, VDDp and IOVCC, though with slightly
larger tolerances than the previous datasheet. VDD and VDDp can both go
from 3.0 V to 5.0 V. DCDC_EN is indeed an additional GPIO to enable the
VDDp supply.

I think you'd need something along these lines:

        - vdd-supply: LED power supply (3.0-5.0 V)
        - vddp-supply: power IC supply (3.0-5.0 V)
        - iovcc-supply: LCM power supply (1.8 V)
        - dcdc-en-gpios: power IC supply enable
        - led-en-gpios: LED backlight enable

Or perhaps your vddp-supply should be a regulator that's controlled by
the GPIO that you'd put in dcdc-en-gpios. That might work better. That
would leave only led-en-gpios as the only enable GPIOs property, so it
would be okay to keep the name "enable-gpios", I guess.

Thierry

quoted

On Wed, Aug 24, 2016 at 5:15 PM, Thierry Reding
[off-list ref] wrote:

quoted

On Sun, Jul 31, 2016 at 08:45:21PM +0530, Vinay Simha BN wrote:

quoted

Add documentation for lt070me05000 panel

Cc: Archit Taneja <redacted>
Cc: John Stultz <redacted>
Cc: Thierry Reding <redacted>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Vinay Simha BN <redacted>
Acked-by: Rob Herring <robh@kernel.org>

---
v2:
 * incorporated rob herring and thierry reviews
   gpio to gpios, gpio to regulator using fixed regulators
   and pwm backlight is removed, since it is controlled by
   dcs commands
---
 .../bindings/display/panel/jdi,lt070me05000.txt    | 57 ++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt

diff --git a/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt b/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt
new file mode 100644
index 0000000..613b76f
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt

@@ -0,0 +1,57 @@
+JDI model LT070ME05000 1200x1920 7" DSI Panel
+
+Required properties:
+- compatible: should be "jdi,lt070me05000"
+- vddp-supply: phandle of the regulator that provides the supply voltage
+  Power IC supply (3-5V)
+- dcdc_en-supply: phandle of the regulator that provides the supply voltage
+  Power IC supply enable, High active
+- vcc-supply: phandle of the regulator that provides the supply voltage
+  IOVCC , power supply for LCM (1.8V)

I was just going to apply this and wanted to add some information about
how many lanes the panel uses, so I looked at the datasheet linked to in
patch 4/4:

        http://panelone.net/en/7-0-inch/JDI_LT070ME05000_7.0_inch-datasheet

and noticed that the power supplies in the binding here don't match the
ones listed in the datasheet. Granted, the datasheet is somewhat meager,
but it lists the following three input voltages:

        - IOVCC at 1.8 V
        - VDD at 3.0 V
        - VDDP at 3.0 V

This matches in part what the above binding describes, but it's not
quite right, so I'm wondering if the name for dcdc_en-supply came from
the board schematics and reflects the name of the rail on the board
design that provides this rather than the input voltage on the panel.

I think we should follow the names in the panel datasheet so that people
can more easily reference the correct regulators when using this panel
on a different board. I'd suggest:

        - iovcc-supply: phandle of the regulator that supplies power to
          the IOVCC voltage input (1.8 V)
        - vdd-supply: phandle of the regulator that supplies power to
          the VDD voltage input (3.0 V)
        - vddp-supply: phandle of the regulator that supplies power to
          the VDDP voltage input (3.0 V)

Any objections?

Thierry

--
regards,
vinaysimha

-- 
regards,
vinaysimha