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

[Nishanth Menon]

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?
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.

Regards,
Nishanth Menon