linux-kernel - Re: [PATCH] regulator: palmas: Fix SMPS enable/disable/is

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Message-ID: <53A88BF5.9010603@wwwdotorg.org>
Date:	Mon, 23 Jun 2014 14:20:05 -0600
From:	Stephen Warren <swarren@...dotorg.org>
To:	Nishanth Menon <nm@...com>
CC:	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>,
	lkml <linux-kernel@...r.kernel.org>,
	linux-omap <linux-omap@...r.kernel.org>, acourbot@...dia.com,
	gnurou@...il.com, Keerthy <j-keerthy@...com>,
	linux-tegra@...r.kernel.org
Subject: Re: [PATCH] regulator: palmas: Fix SMPS enable/disable/is_enabled

On 06/23/2014 02:11 PM, Nishanth Menon wrote:
> On Mon, Jun 23, 2014 at 2:50 PM, Stephen Warren <swarren@...dotorg.org> wrote:
>> On 06/20/2014 11:26 AM, Nishanth Menon wrote:
>>> We use regmap regulator ops to enable/disable and check if regulator
>>> is enabled for various SMPS. However, these depend on valid
>>> enable_reg, enable_mask and enable_value in regulator descriptor.
>>>
>>> Currently we do not populate these for SMPS other than SMPS10, this
>>> results in spurious results as regmap assumes that the values are
>>> valid and ends up reading register 0x0 RTC:SECONDS_REG on Palmas
>>> variants that do have RTC! To fix this, we update proper parameters
>>> for the descriptor fields.
>>>
>>> Further, we want to ensure the behavior consistent with logic
>>> prior to commit dbabd624d4eec50b6, where, once you do a set_mode,
>>> enable/disable ensure the logic remains consistent and configures
>>> Palmas to the configuration that we set with set_mode (since the
>>> configuration register is common). To do this, we can rely on the
>>> regulator core's regulator_register behavior where the regulator
>>> descriptor pointer provided by the regulator driver is stored. (no
>>> reallocation and copy is done). This lets us update the enable_value
>>> post registration, to remain consistent with the mode we configure as
>>> part of set_mode.
>>>
>>> Fixes: dbabd624d4eec50b6 ("regulator: palmas: Reemove open coded functions with helper functions")
>>> Reported-by: Alexandre Courbot <acourbot@...dia.com>
>>> Signed-off-by: Nishanth Menon <nm@...com>
>>
>> Unfortunately, there is still some lingering problem in the original
>> commit. In next-20130623 (and indeed since at least next-20140611),
>> neither the LCD panel or HDMI work on the NVIDIA Dalmore board.
>> Reverting this commit (just for conflicts) and the original problematic
>> commit "regulator: palmas: Reemove open coded functions with helper
>> functions" solves this. I see the following on boot:
>>
>>> [    3.558776] tegra-dsi 54300000.dsi: cannot get VDD supply
>>> [    3.564272] platform 54300000.dsi: Driver tegra-dsi requests probe deferral
>>> [    3.571990] tegra-hdmi 54280000.hdmi: failed to get PLL regulator
>>> [    3.578377] platform 54280000.hdmi: Driver tegra-hdmi requests probe deferral
>>
>> ... but probe deferral never completes, yet with your "remove open coded
>> ..." patch reverted, it all works fine.
>>
>> Can you please take another look at the original patch?
> 
> Will let keerthy (original patch author) comment on it.
> 
> arch/arm/boot/dts/tegra114-dalmore.dts tps65090, avdd_lcd_reg I
> suppose is the path in question?
> 
> Seems to use drivers/mfd/tps65090.c and
> drivers/regulator/tps65090-regulator.c and not palmas?
> 
> Am I looking at the right dts?

Yes, that's the right DTS.

There's both a 65090 and a Palmas on the board. It's probably simpler to
look at the HDMI PLL regulator, since the path to the Palmas is more
obvious:

/ {
	host1x@...00000 {
		hdmi@...80000 {
			pll-supply = <&palmas_smps3_reg>;
...
	i2c@...0d000 {
		palmas: tps65913@58 {
			compatible = "ti,palmas";
			pmic {
				compatible = "ti,tps65913-pmic",
						"ti,palmas-pmic";
				regulators {
					palmas_smps3_reg: smps3 {

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