Re: [PATCH RESEND] thermal: Add QPNP PMIC temperature alarm driver

Georgi Djakov
2014-09-15T16:02:27Z

Hi,

On 09/15/2014 06:03 PM, Ivan T. Ivanov wrote:
> Add support for the temperature alarm peripheral found inside
> Qualcomm plug-and-play (QPNP) PMIC chips. The temperature alarm
> peripheral outputs a pulse on an interrupt line whenever the
> thermal over temperature stage value changes. Implement an ISR
> to manage this interrupt.
>
> Register a thermal zone device in sysfs with mulitple trip points

s/mulitple/multiple/

> corresponding to the physical threshold temperatures between over
> temperature stages. The temperature reported by this thermal
> zone device should reflect the actual PMIC die temperature if an
> ADC is present on the given PMIC. If no ADC is present, then the
> reported temperature should be estimated from the over
> temperature stage value.
>
> Send a notification to userspace via sysfs_notify() whenever the
> over temperature stage value changes.
>
> Cc: David Collins <collinsd@codeaurora.org>
> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
> ---
> .../bindings/thermal/qpnp-temp-alarm.txt | 27 ++
> drivers/thermal/Kconfig | 12 +
> drivers/thermal/Makefile | 1 +
> drivers/thermal/qpnp-temp-alarm.c | 519 +++++++++++++++++++++
> 4 files changed, 559 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/thermal/qpnp-temp-alarm.txt
> create mode 100644 drivers/thermal/qpnp-temp-alarm.c
>
> diff --git a/Documentation/devicetree/bindings/thermal/qpnp-temp-alarm.txt b/Documentation/devicetree/bindings/thermal/qpnp-temp-alarm.txt
> new file mode 100644
> index 0000000..7eecb74
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/thermal/qpnp-temp-alarm.txt
> @@ -0,0 +1,27 @@
> +Qualcomm QPNP PMIC Temperature Alarm
> +
> +QPNP temperature alarm peripherals are found inside of Qualcomm PMIC chips
> +that utilize the Qualcomm SPMI implementation. These peripherals provide an
> +interrupt signal and status register to identify high PMIC die temperature.
> +
> +Required properties:
> +- compatible: Should contain "qcom,qpnp-temp-alarm".
> +- reg: Specifies the SPMI address temperature alarm device.

SPMI address _of_ the temperature alarm device?

> +- interrupts: PMIC temperature alarm interrupt
> +
> +Optional properties:
> +- label: A string used as a descriptive name for this thermal
> + device. This name should be 19 characters or less.
> +- io-channels: Should contain IIO channel specifier
> +- io-channel-names: "thermal". The ADC channel for temperature reading.

Maybe can be rephrased better such as:
- io-channel-names: should contain "thermal" for the temperature reading ADC channel

> +
> +Example:
> +
> + thermal-alarm@2400 {
> + compatible = "qcom,qpnp-temp-alarm";
> + reg = <0x2400>;
> + interrupts = <0 0x24 0 IRQ_TYPE_EDGE_RISING>;
> + label = "pm8941_tz";
> + io-channels = <&pm8941_vadc VADC_DIE_TEMP>;
> + io-channel-names = "thermal";
> + };

Maybe describe the trip points in the DT?

> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 693208e..7371cf9 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -248,4 +248,16 @@ depends on ARCH_STI && OF
> source "drivers/thermal/st/Kconfig"
> endmenu
>
> +config QPNP_TEMP_ALARM
> + tristate "Qualcomm QPNP Temperature Alarm"
> + depends on OF && REGMAP_SPMI

Seems to depend on IIO too.

> + help
> + This enables a thermal sysfs driver for Qualcomm plug-and-play (QPNP)
> + PMIC devices. It shows up in sysfs as a thermal zone with multiple
> + trip points. The temperature reported by the thermal zone reflects the
> + real time die temperature if an ADC is present or an estimate of the
> + temperature based upon the over temperature stage value. Enabling the
> + thermal zone device via the mode file results in shifting PMIC over
> + temperature shutdown control from hardware to software.
> +
[..]

BR,
Georgi