From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowjanya Komatineni Subject: Re: [PATCH V6 16/21] soc/tegra: pmc: Add pmc wake support for tegra210 Date: Mon, 22 Jul 2019 20:09:47 -0700 Message-ID: <629826f9-c453-386a-9e88-bd64d23b8eab@nvidia.com> References: <1563738060-30213-1-git-send-email-skomatineni@nvidia.com> <1563738060-30213-17-git-send-email-skomatineni@nvidia.com> <0b3d08ea-4633-8a54-ba66-c3f3146a1ece@gmail.com> <71a88a9c-a542-557a-0eaa-3c90112dee0e@nvidia.com> <70ad28cb-c268-cbbe-36f5-39df26617d8e@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <70ad28cb-c268-cbbe-36f5-39df26617d8e@gmail.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Osipenko , thierry.reding@gmail.com, jonathanh@nvidia.com, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, linus.walleij@linaro.org, stefan@agner.ch, mark.rutland@arm.com Cc: pdeschrijver@nvidia.com, pgaikwad@nvidia.com, sboyd@kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, jckuo@nvidia.com, josephl@nvidia.com, talho@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, mperttunen@nvidia.com, spatra@nvidia.com, robh+dt@kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org On 7/22/19 8:03 PM, Dmitry Osipenko wrote: > 23.07.2019 4:52, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >> On 7/22/19 6:41 PM, Dmitry Osipenko wrote: >>> 23.07.2019 4:08, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>> 23.07.2019 3:58, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>>> 21.07.2019 22:40, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>>>> This patch implements PMC wakeup sequence for Tegra210 and defines >>>>>> common used RTC alarm wake event. >>>>>> >>>>>> Signed-off-by: Sowjanya Komatineni >>>>>> --- >>>>>> drivers/soc/tegra/pmc.c | 111 ++++++++++++++++++++++++++++++++++++= ++++++++++++ >>>>>> 1 file changed, 111 insertions(+) >>>>>> >>>>>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c >>>>>> index 91c84d0e66ae..c556f38874e1 100644 >>>>>> --- a/drivers/soc/tegra/pmc.c >>>>>> +++ b/drivers/soc/tegra/pmc.c >>>>>> @@ -57,6 +57,12 @@ >>>>>> #define PMC_CNTRL_SYSCLK_OE BIT(11) /* system clock enable */ >>>>>> #define PMC_CNTRL_SYSCLK_POLARITY BIT(10) /* sys clk polarity */ >>>>>> #define PMC_CNTRL_MAIN_RST BIT(4) >>>>>> +#define PMC_CNTRL_LATCH_WAKEUPS BIT(5) >>>> Please follow the TRM's bits naming. >>>> >>>> PMC_CNTRL_LATCHWAKE_EN >>>> >>>>>> +#define PMC_WAKE_MASK 0x0c >>>>>> +#define PMC_WAKE_LEVEL 0x10 >>>>>> +#define PMC_WAKE_STATUS 0x14 >>>>>> +#define PMC_SW_WAKE_STATUS 0x18 >>>>>> =20 >>>>>> #define DPD_SAMPLE 0x020 >>>>>> #define DPD_SAMPLE_ENABLE BIT(0) >>>>>> @@ -87,6 +93,11 @@ >>>>>> =20 >>>>>> #define PMC_SCRATCH41 0x140 >>>>>> =20 >>>>>> +#define PMC_WAKE2_MASK 0x160 >>>>>> +#define PMC_WAKE2_LEVEL 0x164 >>>>>> +#define PMC_WAKE2_STATUS 0x168 >>>>>> +#define PMC_SW_WAKE2_STATUS 0x16c >>>>>> + >>>>>> #define PMC_SENSOR_CTRL 0x1b0 >>>>>> #define PMC_SENSOR_CTRL_SCRATCH_WRITE BIT(2) >>>>>> #define PMC_SENSOR_CTRL_ENABLE_RST BIT(1) >>>>>> @@ -1922,6 +1933,55 @@ static const struct irq_domain_ops tegra_pmc_= irq_domain_ops =3D { >>>>>> .alloc =3D tegra_pmc_irq_alloc, >>>>>> }; >>>>>> =20 >>>>>> +static int tegra210_pmc_irq_set_wake(struct irq_data *data, unsigne= d int on) >>>>>> +{ >>>>>> + struct tegra_pmc *pmc =3D irq_data_get_irq_chip_data(data); >>>>>> + unsigned int offset, bit; >>>>>> + u32 value; >>>>>> + >>>>>> + if (data->hwirq =3D=3D ULONG_MAX) >>>>>> + return 0; >>>>>> + >>>>>> + offset =3D data->hwirq / 32; >>>>>> + bit =3D data->hwirq % 32; >>>>>> + >>>>>> + /* >>>>>> + * Latch wakeups to SW_WAKE_STATUS register to capture events >>>>>> + * that would not make it into wakeup event register during LP0 ex= it. >>>>>> + */ >>>>>> + value =3D tegra_pmc_readl(pmc, PMC_CNTRL); >>>>>> + value |=3D PMC_CNTRL_LATCH_WAKEUPS; >>>>>> + tegra_pmc_writel(pmc, value, PMC_CNTRL); >>>>>> + udelay(120); >>>>> Why it takes so much time to latch the values? Shouldn't some status-= bit >>>>> be polled for the completion of latching? >>>>> >>>>> Is this register-write really getting buffered in the PMC? >>>>> >>>>>> + value &=3D ~PMC_CNTRL_LATCH_WAKEUPS; >>>>>> + tegra_pmc_writel(pmc, value, PMC_CNTRL); >>>>>> + udelay(120); >>>>> 120 usecs to remove latching, really? >>>>> >>>>>> + tegra_pmc_writel(pmc, 0, PMC_SW_WAKE_STATUS); >>>>>> + tegra_pmc_writel(pmc, 0, PMC_SW_WAKE2_STATUS); >>>>>> + >>>>>> + tegra_pmc_writel(pmc, 0, PMC_WAKE_STATUS); >>>>>> + tegra_pmc_writel(pmc, 0, PMC_WAKE2_STATUS); >>>>>> + >>>>>> + /* enable PMC wake */ >>>>>> + if (data->hwirq >=3D 32) >>>>>> + offset =3D PMC_WAKE2_MASK; >>>>>> + else >>>>>> + offset =3D PMC_WAKE_MASK; >>>>>> + >>>>>> + value =3D tegra_pmc_readl(pmc, offset); >>>>>> + >>>>>> + if (on) >>>>>> + value |=3D 1 << bit; >>>>>> + else >>>>>> + value &=3D ~(1 << bit); >>>>>> + >>>>>> + tegra_pmc_writel(pmc, value, offset); >>>>> Why the latching is done *before* writing into the WAKE registers? Wh= at >>>>> it is latching then? >>>> I'm looking at the TRM doc and it says that latching should be done >>>> *after* writing to the WAKE_MASK / LEVEL registers. >>>> >>>> Secondly it says that it's enough to do: >>>> >>>> value =3D tegra_pmc_readl(pmc, PMC_CNTRL); >>>> value |=3D PMC_CNTRL_LATCH_WAKEUPS; >>>> tegra_pmc_writel(pmc, value, PMC_CNTRL); >>>> >>>> in order to latch. There is no need for the delay and to remove the >>>> "LATCHWAKE_EN" bit, it should be a oneshot action. >>> Although, no. TRM says "stops latching on transition from 1 >>> to 0 (sequence - set to 1,set to 0)", so it's not a oneshot action. >>> >>> Have you tested this code at all? I'm wondering how it happens to work >>> without a proper latching. >> Yes, ofcourse its tested and this sequence to do transition is >> recommendation from Tegra designer. >> Will check if TRM doesn't have update properly or will re-confirm >> internally on delay time... >> >> On any of the wake event PMC wakeup happens and WAKE_STATUS register >> will have bits set for all events that triggered wake. >> After wakeup PMC doesn't update SW_WAKE_STATUS register as per PMC desig= n. >> SW latch register added in design helps to provide a way to capture >> those events that happen right during wakeup time and didnt make it to >> SW_WAKE_STATUS register. >> So before next suspend entry, latching all prior wake events into SW >> WAKE_STATUS and then clearing them. > I'm now wondering whether the latching cold be turned ON permanently > during of the PMC's probe, for simplicity. latching should be done on suspend-resume cycle as wake events gets=20 generates on every suspend-resume cycle. >> LATCHWAKE_EN - When set, enables latching and stops latching on >> transition from 1 to 0 >> There is recommendation of min 120uSec for this transition to stop >> latching. Will double-check why 120uSec > Yes, please check. > >>>>>> + return 0; >>>>>> +} >>>>>> + >>>>>> static int tegra186_pmc_irq_set_wake(struct irq_data *data, unsign= ed int on) >>>>>> { >>>>>> struct tegra_pmc *pmc =3D irq_data_get_irq_chip_data(data); >>>>>> @@ -1954,6 +2014,49 @@ static int tegra186_pmc_irq_set_wake(struct i= rq_data *data, unsigned int on) >>>>>> return 0; >>>>>> } >>>>>> =20 >>>>>> +static int tegra210_pmc_irq_set_type(struct irq_data *data, unsigne= d int type) >>>>>> +{ >>>>>> + struct tegra_pmc *pmc =3D irq_data_get_irq_chip_data(data); >>>>>> + unsigned int offset, bit; >>>>>> + u32 value; >>>>>> + >>>>>> + if (data->hwirq =3D=3D ULONG_MAX) >>>>>> + return 0; >>>>>> + >>>>>> + offset =3D data->hwirq / 32; >>>>>> + bit =3D data->hwirq % 32; >>>>>> + >>>>>> + if (data->hwirq >=3D 32) >>>>>> + offset =3D PMC_WAKE2_LEVEL; >>>>>> + else >>>>>> + offset =3D PMC_WAKE_LEVEL; >>>>>> + >>>>>> + value =3D tegra_pmc_readl(pmc, offset); >>>>>> + >>>>>> + switch (type) { >>>>>> + case IRQ_TYPE_EDGE_RISING: >>>>>> + case IRQ_TYPE_LEVEL_HIGH: >>>>>> + value |=3D 1 << bit; >>>>>> + break; >>>>>> + >>>>>> + case IRQ_TYPE_EDGE_FALLING: >>>>>> + case IRQ_TYPE_LEVEL_LOW: >>>>>> + value &=3D ~(1 << bit); >>>>>> + break; >>>>>> + >>>>>> + case IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING: >>>>>> + value ^=3D 1 << bit; >>>>>> + break; >>>>>> + >>>>>> + default: >>>>>> + return -EINVAL; >>>>>> + } >>>>>> + >>>>>> + tegra_pmc_writel(pmc, value, offset); >>>>> Shouldn't the WAKE_LEVEL be latched as well? >> WAKE_LEVELs dont need any latch as they are the levels SW sets for wake >> trigger and they are not status > Okay. > > [snip]