linux-kernel - Re: [RFT v2 00/10] pinctrl: samsung: Remove ugly hack for sharing eint_wakeup

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Message-Id: <20180724091816eucas1p29790b3c45492b261ff154db8056fbb88~EQ2otAHnr1142511425eucas1p2l@eucas1p2.samsung.com>
Date:   Tue, 24 Jul 2018 11:18:13 +0200
From:   Marek Szyprowski <m.szyprowski@...sung.com>
To:     Krzysztof Kozlowski <krzk@...nel.org>,
        Tomasz Figa <tomasz.figa@...il.com>,
        Sylwester Nawrocki <s.nawrocki@...sung.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Kukjin Kim <kgene@...nel.org>,
        Russell King <linux@...linux.org.uk>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-gpio@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Paweł Chmiel <pawel.mikolaj.chmiel@...il.com>,
        Sylwester Nawrocki <snawrocki@...nel.org>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Alim Akhtar <alim.akhtar@...sung.com>,
        Pankaj Dubey <pankaj.dubey@...sung.com>
Subject: Re: [RFT v2 00/10] pinctrl: samsung: Remove ugly hack for sharing
 eint_wakeup_mask

Hi Krzysztof,

On 2018-07-23 19:52, Krzysztof Kozlowski wrote:
> Hi All,
>
> Changes since v1
> ================
> 1. Add Tomasz's ack.
> 2. Reword description in patch 6/10.
>
>
> Tests
> =====
> This is both request for comments and requests for tests. Only basic
> tests were done, including suspend to RAM on Odroid U3 (Exynos4412)
> with max7768 RTC wakeup. Please kindly test it with devices capable of
> suspending and resuming. I am mostly thinking about S5Pv210-based (Aria),
> Trats, Trats2 and TM2 (Exynos5433). Existing platforms should not be
> broken however changing external interrupt wakeup mask was not done
> on Exynos5433.

Works fine on Exynos5433 TM2 with some additional patches related to
suspend/resume handling of the PMU. It handles only EINT0..EINT31 pins
for now. Exynos5433 has more external interrupt wakeup lines: EINT32-63
located at banks GPF1[0..7], GPF2[0..3], GPF3[0..3], GPF4[0..7] and
GPF5[0..7]. They can be configured as wakeup sources in
EXYNOS5433_EINT_WAKEUP_MASK1 (0x062C) PMU register. Handling of them
can be added later when it will be really needed.

Tested-by: Marek Szyprowski <m.szyprowski@...sung.com>

> Description
> ===========
> The Exynos/S5Pv210 machine suspend code needs to write the external
> interrupt mask during suspend.  The mask is controlled by pin controller
> driver: the exynos_wkup_irq_set_wake() in IRQ chip for these wakeup
> interrupts.
>
> Therefore pinctrl driver code exposed an exynos_get_eint_wake_mask()
> function which was later used as an extern in machine code.
>
> This is quite ugly way of combining driver and machine code,
> not portable triggering Sparse and GCC warnings.
>
>
> This might break suspend capability S5Pv210 on with older DTBs (thus
> breaks DTB compatibility), however:
> 1. just "might" because in case of using older DTB, the wakeup mask
>     will not be changed during suspend and default reset value (all
>     interrupts non-masked) should work,
> 2. mainline support for S5Pv210 with DTB is limited and suspend
>     to RAM already might be broken.
>
>
> Dependencies
> ============
> 1. The first seven patches should be taken through one tree,
>     preferably samsung-pinctrl,
> 2. The DTS patch (7/10) for S5Pv210 should go into next cycle,
> 3. The remaining patches (8-10) should go after all previous,
>     so probably another release cycle.
>
>
> Best regards,
> Krzysztof
>
> Krzysztof Kozlowski (10):
>    pinctrl: samsung: Define suspend and resume callbacks for all banks
>      and SoCs
>    pinctrl: samsung: Document suspend and resume members
>    pinctrl: samsung: Document hidden requirement about one external
>      wakeup
>    pinctrl: samsung: Add dedicated compatible for S5Pv210 wakeup
>      interrupts
>    ARM: exynos: Define EINT_WAKEUP_MASK registers for S5Pv210 and
>      Exynos5433
>    pinctrl: samsung: Write external wakeup interrupt mask
>    ARM: dts: s5pv210: Switch to S5Pv210 specific pinctrl wakeup
>      compatible
>    ARM: s5pv210: Remove legacy setting of external wakeup interrupts
>    ARM: exynos: Remove legacy setting of external wakeup interrupts
>    pinctrl: samsung: Remove legacy API for handling external wakeup
>      interrupts mask
>
>   .../bindings/pinctrl/samsung-pinctrl.txt           | 11 ++-
>   arch/arm/boot/dts/s5pv210.dtsi                     |  2 +-
>   arch/arm/mach-exynos/common.h                      |  2 -
>   arch/arm/mach-exynos/suspend.c                     | 16 +++--
>   arch/arm/mach-s5pv210/common.h                     |  1 -
>   arch/arm/mach-s5pv210/pm.c                         | 16 +++--
>   drivers/pinctrl/samsung/pinctrl-exynos-arm.c       | 16 +++++
>   drivers/pinctrl/samsung/pinctrl-exynos.c           | 78 +++++++++++++++++++---
>   drivers/pinctrl/samsung/pinctrl-samsung.h          | 11 +++
>   include/linux/soc/samsung/exynos-regs-pmu.h        |  8 ++-
>   10 files changed, 136 insertions(+), 25 deletions(-)
>

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland