Subject: [RFC PATCH 09/11] ARM: OMAP4+: thermal: introduce bandgap temperature sensor

From: [email-masked] (Tony Lindgren)
Date: Fri, 1 Jun 2012 04:42:39 -0700

* Eduardo Valentin <[email-masked]> [120525 01:31]:
> In the System Control Module, OMAP supplies a voltage reference
> and a temperature sensor feature that are gathered in the band
> gap voltage and temperature sensor (VBGAPTS) module. The band
> gap provides current and voltage reference for its internal
> circuits and other analog IP blocks. The analog-to-digital
> converter (ADC) produces an output value that is proportional
> to the silicon temperature.
> 
> This patch provides a platform driver which expose this feature.
> It is moduled as a MFD child of the System Control Module core
> MFD driver.
> 
> This driver provides only APIs to access the device properties,
> like temperature, thresholds and update rate.

Here too you a better long term solution is probably to ioremap
the temp sensor registers for the driver. That way alloc_mem_region()
provides some checks so the driver won't stomp over other registers.

If you need to use omap_ctrl_read/write here, then we should at
least clearly understand and document why it needs to be done that
way instead of following standard ioremap + readl/writel.

Regards,

Tony