thermal: ti-soc-thermal: Fix stuck sensor with continuous mode for 4430

At least for 4430, trying to use the single conversion mode eventually
hangs the thermal sensor. This can be quite easily seen with errors:

thermal thermal_zone0: failed to read out thermal zone (-5)

Also, trying to read the temperature shows a stuck value with:

$ while true; do cat /sys/class/thermal/thermal_zone0/temp; done

Where the temperature is not rising at all with the busy loop.

Additionally, the EOCZ (end of conversion) bit is not rising on 4430 in
single conversion mode while it works fine in continuous conversion mode.
It is also possible that the hung temperature sensor can affect the
thermal shutdown alert too.

Let's fix the issue by adding TI_BANDGAP_FEATURE_CONT_MODE_ONLY flag and
use it for 4430.

Note that we also need to add udelay to for the EOCZ (end of conversion)
bit polling as otherwise we have it time out too early on 4430. We'll be
changing the loop to use iopoll in the following clean-up patch.

Cc: Adam Ford <aford173@gmail.com>
Cc: Carl Philipp Klemm <philipp@uvos.xyz>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Adam Ford <aford173@gmail.com> #logicpd-torpedo-37xx-devkit
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210205134534.49200-3-tony@atomide.com

thermal: ti-soc-thermal: Enable addition power management

The bandgap sensor can be idled when the processor is too, but it
isn't currently being done, so the power consumption of OMAP3
boards can elevated if the bangap sensor is enabled.

This patch attempts to use some additional power management
to idle the clock to the bandgap when not needed.

Signed-off-by: Adam Ford <aford173@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Tested-by: Andreas Kemnade <andreas@kemnade.info> # GTA04
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200911123157.759379-1-aford173@gmail.com

thermal: ti-soc-thermal: Use GPIO descriptors

This switches the TI SoC thermal driver to use GPIO
descriptors instead of retrieveing a GPIO number from the
device tree and requesting the GPIO separately.

Cc: Keerthy <j-keerthy@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200229210532.173430-1-linus.walleij@linaro.org

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 51 franklin st fifth floor boston ma 02110
1301 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 246 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.674189849@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

thermal: ti-soc-thermal: remove dead code

Majority of this code (i.e. functions from ti-bandgap.c) has been
introduced in May 2013 by commit eb982001dbd8 ("thermal: introduce TI
SoC thermal driver"). Just remove it altogether (in case it is needed
it can be easily resurrected from git repo).

While at it fix incorrect "not used" comments.

Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal: ti-soc-thermal: Remove redundant constants

Now that slope and offset data are being passed from
device tree no need to populate in driver data.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal: ti-soc-thermal: add OMAP36xx support

Add OMAP36xx support to ti-soc-thermal driver. This
chip is also unreliable. The data provided here is
based on OMAP36xx TRM:
http://www.ti.com/lit/ug/swpu177aa/swpu177aa.pdf

Signed-off-by: Eduardo Valentin <edubezva@gmail.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

ti-soc-thermal: implement omap3 support

This adds support for OMAP3 chips to ti-soc-thermal. As requested by
TI people, it is marked unreliable and warning is printed.

Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal: ti-soc-thermal: OMAP5: Implement Workaround for Errata i813

DESCRIPTION

Spurious Thermal Alert: Talert can happen randomly while the device remains
under the temperature limit defined for this event to trig. This spurious
event is caused by a incorrect re-synchronization between clock domains.
The comparison between configured threshold and current temperature value
can happen while the value is transitioning (metastable), thus causing
inappropriate event generation. No spurious event occurs as long as the
threshold value stays unchanged. Spurious event can be generated while a
thermal alert threshold is modified in
CONTROL_BANDGAP_THRESHOLD_MPU/GPU/CORE/DSPEVE/IVA_n.

WORKAROUND

Spurious event generation can be avoided by performing following sequence
when the threshold is modified:
1. Mask the hot/cold events at the thermal IP level.
2. Modify Threshold.
3. Unmask the hot/cold events at the thermal IP level.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal: ti-soc-thermal: dra7: Implement Workaround for Errata i814

Bandgap Temperature read Dtemp can be corrupted

DESCRIPTION
Read accesses to registers listed below can be corrupted due to
incorrect resynchronization between clock domains.

Read access to registers below can be corrupted :
• CTRL_CORE_DTEMP_MPU/GPU/CORE/DSPEVE/IVA_n (n = 0 to 4)
• CTRL_CORE_TEMP_SENSOR_MPU/GPU/CORE/DSPEVE/IVA_n

WORKAROUND
Multiple reads to CTRL_CORE_TEMP_SENSOR_MPU/GPU/CORE/DSPEVE/IVA[9:0]:
BGAP_DTEMPMPU/GPU/CORE/DSPEVE/IVA is needed to discard false value and
read right value:
1. Perform two successive reads to BGAP_DTEMP bit field.
(a) If read1 returns Val1 and read2 returns Val1, then
right value is Val1.
(b) If read1 returns Val1, read 2 returns Val2, a third
read is needed.
2. Perform third read
(a) If read3 returns Val2 then right value is Val2.
(b) If read3 returns Val3, then right value is Val3.

The above in gist means if val1 and val2 are the same then we can go
ahead with that value else we need a third read which will be right
since synchronization will be complete by then.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

thermal: ti-soc-thermal: add dra752 chip to device table

Add support to TI dra752 chips by adapting the driver
device table.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

thermal: introduce TI SoC thermal driver

This patch moves the ti-soc-thermal driver out of
the staging tree to the thermal tree.

Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Rob Landley <rob@landley.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <eduardo.valentin@ti.com>
Cc: J Keerthy <j-keerthy@ti.com>
Cc: Radhesh Fadnis <radhesh.fadnis@ti.com>
Cc: Cyril Roelandt <tipecaml@gmail.com>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: linux-pm@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>