[v2,4/5] ARM: dts: imx6sx: Use nvmem-cells for tempmon
diff mbox

Message ID 3cda26e557510055f05cea92b81678743e0ea9e3.1500041281.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 imx6sx accessing OCOTP directly is wrong because the ocotp clock
needs to be enabled first. Use the nvmem-cells binding instead.

This requirement does not apply to older imx6qdl chips because there the
ocotp access clock (clk_ipg_s) is always enabled.

This is visible by comparing the "System Clocks, Gating, and Override"
tables (OCOTP rows) in the 6DQ and 6SX manuals:
http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6SXRM.pdf
http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6DQRM.pdf

This happens to work right now because the ocotp clock might be enabled
for some other reason. In particular the it might be enabled from the
bootloader and it only gets disabled late during boot in
clk_disable_unused, after imx-thermal has completed probing.

If imx-thermal is compiled as a module then the system can hang on
probe.

Reported-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
---
 arch/arm/boot/dts/imx6sx.dtsi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

Comments

Shawn Guo July 25, 2017, 8:11 a.m. UTC | #1
On Fri, Jul 14, 2017 at 05:11:09PM +0300, Leonard Crestez wrote:
> On imx6sx accessing OCOTP directly is wrong because the ocotp clock
> needs to be enabled first. Use the nvmem-cells binding instead.
> 
> This requirement does not apply to older imx6qdl chips because there the
> ocotp access clock (clk_ipg_s) is always enabled.
> 
> This is visible by comparing the "System Clocks, Gating, and Override"
> tables (OCOTP rows) in the 6DQ and 6SX manuals:
> http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6SXRM.pdf
> http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6DQRM.pdf
> 
> This happens to work right now because the ocotp clock might be enabled
> for some other reason. In particular the it might be enabled from the
> bootloader and it only gets disabled late during boot in
> clk_disable_unused, after imx-thermal has completed probing.
> 
> If imx-thermal is compiled as a module then the system can hang on
> probe.
> 
> Reported-by: Lothar Waßmann <LW@KARO-electronics.de>
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>

I cannot apply dts changes until the driver part gets landed on
mainline.  Please remind me when dts patches can be applied.

Shawn

> ---
>  arch/arm/boot/dts/imx6sx.dtsi | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/imx6sx.dtsi b/arch/arm/boot/dts/imx6sx.dtsi
> index f16b9df..580af30 100644
> --- a/arch/arm/boot/dts/imx6sx.dtsi
> +++ b/arch/arm/boot/dts/imx6sx.dtsi
> @@ -675,7 +675,8 @@
>  				compatible = "fsl,imx6sx-tempmon", "fsl,imx6q-tempmon";
>  				interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
>  				fsl,tempmon = <&anatop>;
> -				fsl,tempmon-data = <&ocotp>;
> +				nvmem-cells = <&tempmon_calib>, <&tempmon_temp_grade>;
> +				nvmem-cell-names = "calib", "temp_grade";
>  				clocks = <&clks IMX6SX_CLK_PLL3_USB_OTG>;
>  			};
>  
> @@ -993,9 +994,19 @@
>  			};
>  
>  			ocotp: ocotp@021bc000 {
> +				#address-cells = <1>;
> +				#size-cells = <1>;
>  				compatible = "fsl,imx6sx-ocotp", "syscon";
>  				reg = <0x021bc000 0x4000>;
>  				clocks = <&clks IMX6SX_CLK_OCOTP>;
> +
> +				tempmon_calib: calib@38 {
> +					reg = <0x38 4>;
> +				};
> +
> +				tempmon_temp_grade: temp-grade@20 {
> +					reg = <0x20 4>;
> +				};
>  			};
>  
>  			sai1: sai@021d4000 {
> -- 
> 2.7.4
>
Shawn Guo Oct. 18, 2017, 2:29 a.m. UTC | #2
On Fri, Jul 14, 2017 at 05:11:09PM +0300, Leonard Crestez wrote:
> On imx6sx accessing OCOTP directly is wrong because the ocotp clock
> needs to be enabled first. Use the nvmem-cells binding instead.
> 
> This requirement does not apply to older imx6qdl chips because there the
> ocotp access clock (clk_ipg_s) is always enabled.
> 
> This is visible by comparing the "System Clocks, Gating, and Override"
> tables (OCOTP rows) in the 6DQ and 6SX manuals:
> http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6SXRM.pdf
> http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6DQRM.pdf
> 
> This happens to work right now because the ocotp clock might be enabled
> for some other reason. In particular the it might be enabled from the
> bootloader and it only gets disabled late during boot in
> clk_disable_unused, after imx-thermal has completed probing.
> 
> If imx-thermal is compiled as a module then the system can hang on
> probe.
> 
> Reported-by: Lothar Waßmann <LW@KARO-electronics.de>
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>

I applied patch #4 and #5 to IMX tree for avoiding merge conflict.  Rui
will drop them from thermal tree.

Shawn

Patch
diff mbox

diff --git a/arch/arm/boot/dts/imx6sx.dtsi b/arch/arm/boot/dts/imx6sx.dtsi
index f16b9df..580af30 100644
--- a/arch/arm/boot/dts/imx6sx.dtsi
+++ b/arch/arm/boot/dts/imx6sx.dtsi
@@ -675,7 +675,8 @@ 
 				compatible = "fsl,imx6sx-tempmon", "fsl,imx6q-tempmon";
 				interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
 				fsl,tempmon = <&anatop>;
-				fsl,tempmon-data = <&ocotp>;
+				nvmem-cells = <&tempmon_calib>, <&tempmon_temp_grade>;
+				nvmem-cell-names = "calib", "temp_grade";
 				clocks = <&clks IMX6SX_CLK_PLL3_USB_OTG>;
 			};
 
@@ -993,9 +994,19 @@ 
 			};
 
 			ocotp: ocotp@021bc000 {
+				#address-cells = <1>;
+				#size-cells = <1>;
 				compatible = "fsl,imx6sx-ocotp", "syscon";
 				reg = <0x021bc000 0x4000>;
 				clocks = <&clks IMX6SX_CLK_OCOTP>;
+
+				tempmon_calib: calib@38 {
+					reg = <0x38 4>;
+				};
+
+				tempmon_temp_grade: temp-grade@20 {
+					reg = <0x20 4>;
+				};
 			};
 
 			sai1: sai@021d4000 {