[PATCH] ARM: DTS: OMAP4: Panda/SDP: twl6030: fix mux for IRQ pin and msecure line

[Kevin Hilman]

Nishanth Menon <nm at ti.com> writes:

> On Fri, May 24, 2013 at 4:19 PM, Kevin Hilman <khilman at linaro.org> wrote:
>> Nishanth Menon <nm at ti.com> writes:
>>
>>> On 15:09-20130524, Nishanth Menon wrote:
>>>> On 12:28-20130524, Kevin Hilman wrote:
>>>> > Earlier commits ensured proper muxing of pins related to proper
>>>> > TWL6030 behavior: see commit 265a2bc8 (ARM: OMAP3: TWL4030: ensure
>>>> > sys_nirq1 is mux'd and wakeup enabled) and commit 1ef43369 (ARM:
>>>> > OMAP4: TWL: mux sys_drm_msecure as output for PMIC).
>>>> >
>>>> > However these only fixed legacy boot and not DT boot.  For DT boot,
>>>> > the default mux values need to be set properly in DT.
>>>> >
>>>> > Cc: Tony Lindgren <tony at atomide.com>
>>>> > Signed-off-by: Kevin Hilman <khilman at linaro.org>
>>>> > ---
>>>> > Applies on v3.10-rc2
>>>> >
>>>> >  arch/arm/boot/dts/omap4-panda-common.dtsi | 8 ++++++++
>>>> >  arch/arm/boot/dts/omap4-sdp.dts           | 8 ++++++++
>>>> >  2 files changed, 16 insertions(+)
>>>> >
>>>> > diff --git a/arch/arm/boot/dts/omap4-panda-common.dtsi b/arch/arm/boot/dts/omap4-panda-common.dtsi
>>>> > index 03bd60d..a7a9bc0 100644
>>>> > --- a/arch/arm/boot/dts/omap4-panda-common.dtsi
>>>> > +++ b/arch/arm/boot/dts/omap4-panda-common.dtsi
>>>> > @@ -59,6 +59,7 @@
>>>> >  &omap4_pmx_core {
>>>> >    pinctrl-names = "default";
>>>> >    pinctrl-0 = <
>>>> > +                  &twl6030_pins
>>>> >                    &twl6040_pins
>>>> >                    &mcpdm_pins
>>>> >                    &mcbsp1_pins
>>>> > @@ -66,6 +67,13 @@
>>>> >                    &tpd12s015_pins
>>>> >    >;
>>>> >
>>>> > +  twl6030_pins: pinmux_twl6030_pins {
>>>> > +          pinctrl-single,pins = <
>>>> > +                  0x15e 0x4118    /* sys_nirq1.sys_nirq1 OMAP_WAKEUP_EN | INPUT_PULLUP | MODE0 */
>>>> I can understand this - IRQ request comes here.
>>>> verified on OMAP4460 Panda-ES.
>>>> # omapconf read 0x4A10019C
>>>> 4118011B
>>>>
>>>> > +                  0x14 0x0        /* fref_clk0_out.sys_drm_msecure OUTPUT */
>>>> I do not understand this.
>>>> OMAP4460 TRM:
>>>> Register: CONTROL_WKUP_PAD0_FREF_CLK0_OUT_PAD1_FREF_CLK3_REQ
>>>> omapconf read 0x4A31E054
>>>> 010F010F
>>>>
>>>> I do not understand this configuration. mux modes for
>>>> FREF_CLK0_OUT_MUXMODE:
>>>> 0x0: Select fref_clk0_out
>>>> 0x1: Select fref_clk1_req
>>>> 0x2: Reserved
>>>> 0x3: Select gpio_wk6
>>>> 0x5: Select sdmmc2_dat7
>>>> 0x6: Select hw_dbg6
>>>> 0x7: Select safe_mode
>>>>
>>>> Why are we setting mode 0(clk out) here?
>>>
>>> I did a bit more research into this:
>>> MSECURE line needs to be set for us to set anything with TWL6030 RTC.
>>
>> Yes, the commit referenced in the changelog described that in detail.
>>
>>> PandaBoard ES(4460) = this is on OMAP PIN AD4
>>> PandaBoard (4430) = this is on OMAP PIN AD2
>>>
>>> translating this back,
>>> PandaBoard ES OMAp4460 pin AD4:
>>> FREF_CLK3_OUT/FREF_CLK2_REQ/SYS_SECURE_INDICATOR/GPIO_WK31/C2C_WAKEREQOUT/SDMMC2_DAT5/ATTILA_HW_DBG8/SAFE_MODE
>>> This is at register 0x4A31E054(higher 16 bits) - however since we are GP device,
>>> SYS_SECURE_INDICATOR(mode 2) is reserved.
>>> PandaBoard OMAP4430 pin AD2:
>>> FREF_CLK0_OUT/FREF_CLK1_REQ/SYS_DRM_MSECURE/GPIO_WK6/SDMMC2_DAT7/ATTILA_HW_DBG6/SAFE_MOD
>>> This is at register 0x4A31E054(lower 16 bits) - however since we are GP device,
>>> SYS_DRM_MSECURE(mode 2) is reserved.
>>>
>>> To use RTC, we will have to use GPIO.
>>> on pandaboard ES, we need GPIO31 and PandaBoard, 6.
>>>
>>> Further the pinctrl offsets will vary as well between the same.
>>>
>>> IMHO, we need GPIO support and pinmux appropritate to the same to allow
>>> RTC to work.
>>
>> I don't follow at all what you're trying to say.  The current settings
>> are working fine and have been tested on both 4430/Panda and 4460/Panda-ES.
>>
>> The goal of this patch is to make default mux settings for twl6030 for
>> DT boot match current legacy boot in mainline.
>>
>> The commits referenced in the changelog setup some default muxing for
>> twl6030 (see changelogs referenced and mux calls in
>> twl-common.c:omap4_pmic_init())
>>
>> Without those mux settings, RTC wakeup on legacy boot does not work
>> (tested on 4430/panda, 4460/Panda with recent u-boot v2013.04 where most
>> of the old mux setup is gone.)  With those settings, RTC wakeup works.
>>
>> Yes, the TRM has some mode bits marked as reserved, but that doesn't
>> mean they don't work.  It just means the documentation is squirreled
>> away in the secure TRM addendum.
>>
> Actually 2 things:
>
> a) patch seems to do the wrong thing for 4460 - 0x18 offset should
> have been used instead of 0x14 which is correct for 4430?

I see, thanks.  I'll double check the TRMs.

> b) yes, I understand,  the current settings we did worked, but the
> mode(0) we are setting to is real weird - we are setting it up for
> clk0 out - I cant even think why it is even working in the first place
> :( - is it because we are pumping out sysclkout and as a result we are
> lucky that msecure is being sampled at the right point by twl6030
> allowing rtc access? either way, IMHO, the configuration is wrong.

Ah, yes.  Mode zero is definitely wrong.   When I did the original patch
for legacy mode, I just duplicated the settings u-boot was using.  Guess
it's a fluke that it works.

Yet another thing wrong with my patch:  the fref_clk0 pad is in the WKUP
padconf section, and I put it at offset 0x14 in the CORE section, which
is yet another wrong place.

Let me respin this after some more doc reading.

Thanks for the detailed review,

Kevin