[v2,1/5] thermal: imx: Add nvmem-cells alternate binding for OCOTP access
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Message ID 79ad86fbce37b169342704c397f0a1dbae0cfb75.1500041281.git.leonard.crestez@nxp.com
State Accepted, archived
Delegated to: Zhang Rui
Headers show

Commit Message

Leonard Crestez July 14, 2017, 2:11 p.m. UTC
On newer imx SOCs accessing OCOTP directly is wrong because the ocotp
clock needs to be enabled first. Add a binding for accessing the same
values through the imx-ocotp nvmem driver using nvmem-cells. This is
similar to other thermal drivers.

The old binding is preserved for compatibility and because it still
works fine on imx6qdl series chips.

In theory this problem could be solved by adding a reference to the
OCOTP clock instead but it is better to hide such details in a specific
nvmem driver.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
---
 Documentation/devicetree/bindings/thermal/imx-thermal.txt | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Rob Herring July 17, 2017, 6:57 p.m. UTC | #1
On Fri, Jul 14, 2017 at 05:11:06PM +0300, Leonard Crestez wrote:
> On newer imx SOCs accessing OCOTP directly is wrong because the ocotp
> clock needs to be enabled first. Add a binding for accessing the same
> values through the imx-ocotp nvmem driver using nvmem-cells. This is
> similar to other thermal drivers.
> 
> The old binding is preserved for compatibility and because it still
> works fine on imx6qdl series chips.
> 
> In theory this problem could be solved by adding a reference to the
> OCOTP clock instead but it is better to hide such details in a specific
> nvmem driver.
> 
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> ---
>  Documentation/devicetree/bindings/thermal/imx-thermal.txt | 7 +++++++
>  1 file changed, 7 insertions(+)

Acked-by: Rob Herring <robh@kernel.org>

Patch
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diff --git a/Documentation/devicetree/bindings/thermal/imx-thermal.txt b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
index 3c67bd5..28be51a 100644
--- a/Documentation/devicetree/bindings/thermal/imx-thermal.txt
+++ b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
@@ -7,10 +7,17 @@  Required properties:
   is higher than panic threshold, system will auto reboot by SRC module.
 - fsl,tempmon : phandle pointer to system controller that contains TEMPMON
   control registers, e.g. ANATOP on imx6q.
+- nvmem-cells: A phandle to the calibration cells provided by ocotp.
+- nvmem-cell-names: Should be "calib", "temp_grade".
+
+Deprecated properties:
 - fsl,tempmon-data : phandle pointer to fuse controller that contains TEMPMON
   calibration data, e.g. OCOTP on imx6q.  The details about calibration data
   can be found in SoC Reference Manual.
 
+Direct access to OCOTP via fsl,tempmon-data is incorrect on some newer chips
+because it does not handle OCOTP clock requirements.
+
 Optional properties:
 - clocks : thermal sensor's clock source.