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thermal: rockchip: support the sleep pinctrl state to avoid glitches in s2r

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When we come out of system suspend state (S3) the tsadc will have been
reset and back at its default state.  While reprogramming the tsadc
it's possible that we'll glitch the output and unintentionally cause
the "over temperature" GPIO to be asserted.  Since the over
temperature GPIO is often hooked up to something that will cause a
reboot or shutdown in hardware, this glitch can be catastrophic on
some boards.

We'll add support for selecting the "sleep" pinctrl state at suspend
time.  Boards can use this to effectively disable the tsadc at suspend
time and avoid glitches when the system is resumed.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
This commit is contained in:
Caesar Wang 2015-10-23 19:25:27 +08:00 committed by Eduardo Valentin
parent 9aba783a2a
commit 7e38a5b1da
1 changed files with 4 additions and 0 deletions
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4
drivers/thermal/rockchip_thermal.c
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@ -638,6 +638,8 @@ static int __maybe_unused rockchip_thermal_suspend(struct device *dev)
clk_disable(thermal->pclk);
clk_disable(thermal->clk);
pinctrl_pm_select_sleep_state(dev);
return 0;
}
@ -674,6 +676,8 @@ static int __maybe_unused rockchip_thermal_resume(struct device *dev)
for (i = 0; i < ARRAY_SIZE(thermal->sensors); i++)
rockchip_thermal_toggle_sensor(&thermal->sensors[i], true);
pinctrl_pm_select_default_state(dev);
return 0;
}