[PATCH] pinctrl: dra: dt-bindings: Fix pull enable/disable

[PATCH] pinctrl: dra: dt-bindings: Fix pull enable/disable

[Nishanth Menon]

The DRA74/72 control module pins have a weak pull up and pull down.
This is configured by bit offset 17. if BIT(17) is 1, a pull up is
selected, else a pull down is selected.

However, this pull resisstor is applied based on BIT(16) -
PULLUDENABLE - if BIT(18) is *0*, then pull as defined in BIT(17) is
applied, else no weak pulls are applied. We defined this in reverse.

Reference: Table 18-5 (Description of the pad configuration register
bits) in Technical Reference Manual Revision (DRA74x revision Q:
SPRUHI2Q Revised June 2014 and DRA72x revision F: SPRUHP2F - Revised
June 2014)

Fixes: 6e58b8f1daaf1a ("ARM: dts: DRA7: Add the dts files for dra7 SoC and dra7-evm board")
Signed-off-by: Nishanth Menon <nm@ti.com>
---
Patch based on v3.16-rc5 tag

1: dra72x-evm:  Boot ok: http://slexy.org/raw/s20I6QXQa (needs MMC filesystem that current dts does not have.
	- Fails in plain Vanilla 3.16-rc5 kernel due to missing patch to handle USB IP instance delta (between dra72x and dra74x) appropriately.
	- Tested with fixes needed: https://patchwork.kernel.org/patch/4565431/ and https://patchwork.kernel.org/patch/4565461/

2: dra7xx-evm:  Boot PASS: http://slexy.org/raw/s21c6X2wOd

Equivalent testing on 3.14 based product kernel:
 dra72x-evm:  Boot PASS: http://slexy.org/raw/s21yIgttJw
 dra7xx-evm:  Boot PASS: http://slexy.org/raw/s20w7OZaJJ

It is obvious that current users of padconf have'nt had trouble with
the wrong definitions. I think I might have been the first to discover
this as emmc on beagleboard-X15 (an upcoming platform) exposed this problem.

 include/dt-bindings/pinctrl/dra.h |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/dt-bindings/pinctrl/dra.h b/include/dt-bindings/pinctrl/dra.h
index 002a285..3d33794 100644
--- a/include/dt-bindings/pinctrl/dra.h
+++ b/include/dt-bindings/pinctrl/dra.h
@@ -30,7 +30,8 @@
 #define MUX_MODE14	0xe
 #define MUX_MODE15	0xf
 
-#define PULL_ENA		(1 << 16)
+#define PULL_ENA		(0 << 16)
+#define PULL_DIS		(1 << 16)
 #define PULL_UP			(1 << 17)
 #define INPUT_EN		(1 << 18)
 #define SLEWCONTROL		(1 << 19)
@@ -38,10 +39,10 @@
 #define WAKEUP_EVENT		(1 << 25)
 
 /* Active pin states */
-#define PIN_OUTPUT		0
+#define PIN_OUTPUT		(0 | PULL_DIS)
 #define PIN_OUTPUT_PULLUP	(PIN_OUTPUT | PULL_ENA | PULL_UP)
 #define PIN_OUTPUT_PULLDOWN	(PIN_OUTPUT | PULL_ENA)
-#define PIN_INPUT		INPUT_EN
+#define PIN_INPUT		(INPUT_EN | PULL_DIS)
 #define PIN_INPUT_SLEW		(INPUT_EN | SLEWCONTROL)
 #define PIN_INPUT_PULLUP	(PULL_ENA | INPUT_EN | PULL_UP)
 #define PIN_INPUT_PULLDOWN	(PULL_ENA | INPUT_EN)
-- 
1.7.9.5

Re: [PATCH] pinctrl: dra: dt-bindings: Fix pull enable/disable

[Nishanth Menon]

> 1: dra72x-evm:  Boot ok: http://slexy.org/raw/s20I6QXQa (needs MMC filesystem that current dts does not have.
Oops - missed a character in the link:
http://slexy.org/view/s20I6QXQal

Sorry about the spam.

-- 
Regards,
Nishanth Menon

Re: [PATCH] pinctrl: dra: dt-bindings: Fix pull enable/disable

[Felipe Balbi]

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On Tue, Jul 22, 2014 at 10:39:54AM -0500, Nishanth Menon wrote:
> The DRA74/72 control module pins have a weak pull up and pull down.
> This is configured by bit offset 17. if BIT(17) is 1, a pull up is
> selected, else a pull down is selected.
> 
> However, this pull resisstor is applied based on BIT(16) -
> PULLUDENABLE - if BIT(18) is *0*, then pull as defined in BIT(17) is
> applied, else no weak pulls are applied. We defined this in reverse.
> 
> Reference: Table 18-5 (Description of the pad configuration register
> bits) in Technical Reference Manual Revision (DRA74x revision Q:
> SPRUHI2Q Revised June 2014 and DRA72x revision F: SPRUHP2F - Revised
> June 2014)
> 
> Fixes: 6e58b8f1daaf1a ("ARM: dts: DRA7: Add the dts files for dra7 SoC and dra7-evm board")
> Signed-off-by: Nishanth Menon <nm@ti.com>
> ---

Tested on an upcoming board.

Tested-by: Felipe Balbi <balbi@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>


-- 
balbi

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Re: [PATCH] pinctrl: dra: dt-bindings: Fix pull enable/disable

[Nishanth Menon]

On 07/22/2014 11:47 AM, Felipe Balbi wrote:
> On Tue, Jul 22, 2014 at 10:39:54AM -0500, Nishanth Menon wrote:
>> The DRA74/72 control module pins have a weak pull up and pull down.
>> This is configured by bit offset 17. if BIT(17) is 1, a pull up is
>> selected, else a pull down is selected.
>>
>> However, this pull resisstor is applied based on BIT(16) -
>> PULLUDENABLE - if BIT(18) is *0*, then pull as defined in BIT(17) is
>> applied, else no weak pulls are applied. We defined this in reverse.
>>
>> Reference: Table 18-5 (Description of the pad configuration register
>> bits) in Technical Reference Manual Revision (DRA74x revision Q:
>> SPRUHI2Q Revised June 2014 and DRA72x revision F: SPRUHP2F - Revised
>> June 2014)
>>
>> Fixes: 6e58b8f1daaf1a ("ARM: dts: DRA7: Add the dts files for dra7 SoC and dra7-evm board")
>> Signed-off-by: Nishanth Menon <nm@ti.com>
>> ---
> 
> Tested on an upcoming board.
> 
> Tested-by: Felipe Balbi <balbi@ti.com>
> Acked-by: Felipe Balbi <balbi@ti.com>
> 
> 
Felipe,
Thanks.

Tony,

If you could consider this for the rc cycle it might be great(as well
as for stable). The pull direction error can cause all kinds of
Pull-down Vs Pull-Up contention with severe risk for certain IP
reliability.

-- 
Regards,
Nishanth Menon

Re: [PATCH] pinctrl: dra: dt-bindings: Fix pull enable/disable

[Tony Lindgren]

* Nishanth Menon <nm@ti.com> [140722 11:34]:
> On 07/22/2014 11:47 AM, Felipe Balbi wrote:
> > On Tue, Jul 22, 2014 at 10:39:54AM -0500, Nishanth Menon wrote:
> >> The DRA74/72 control module pins have a weak pull up and pull down.
> >> This is configured by bit offset 17. if BIT(17) is 1, a pull up is
> >> selected, else a pull down is selected.
> >>
> >> However, this pull resisstor is applied based on BIT(16) -
> >> PULLUDENABLE - if BIT(18) is *0*, then pull as defined in BIT(17) is
> >> applied, else no weak pulls are applied. We defined this in reverse.
> >>
> >> Reference: Table 18-5 (Description of the pad configuration register
> >> bits) in Technical Reference Manual Revision (DRA74x revision Q:
> >> SPRUHI2Q Revised June 2014 and DRA72x revision F: SPRUHP2F - Revised
> >> June 2014)
> >>
> >> Fixes: 6e58b8f1daaf1a ("ARM: dts: DRA7: Add the dts files for dra7 SoC and dra7-evm board")
> >> Signed-off-by: Nishanth Menon <nm@ti.com>
> >> ---
> > 
> > Tested on an upcoming board.
> > 
> > Tested-by: Felipe Balbi <balbi@ti.com>
> > Acked-by: Felipe Balbi <balbi@ti.com>
> > 
> > 
> Felipe,
> Thanks.
> 
> Tony,
> 
> If you could consider this for the rc cycle it might be great(as well
> as for stable). The pull direction error can cause all kinds of
> Pull-down Vs Pull-Up contention with severe risk for certain IP
> reliability.

Yes this is a good one for the -rc cycle, applying into
omap-for-v3.16/fixes.

Regards,

Tony