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Date: Tue, 23 Jul 2019 06:25:45 +0300
From: Dmitry Osipenko <digetx@...il.com>
To: Sowjanya Komatineni <skomatineni@...dia.com>,
thierry.reding@...il.com, jonathanh@...dia.com, tglx@...utronix.de,
jason@...edaemon.net, marc.zyngier@....com,
linus.walleij@...aro.org, stefan@...er.ch, mark.rutland@....com
Cc: pdeschrijver@...dia.com, pgaikwad@...dia.com, sboyd@...nel.org,
linux-clk@...r.kernel.org, linux-gpio@...r.kernel.org,
jckuo@...dia.com, josephl@...dia.com, talho@...dia.com,
linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org,
mperttunen@...dia.com, spatra@...dia.com, robh+dt@...nel.org,
devicetree@...r.kernel.org
Subject: Re: [PATCH V6 16/21] soc/tegra: pmc: Add pmc wake support for
tegra210
23.07.2019 6:09, Sowjanya Komatineni пишет:
>
> On 7/22/19 8:03 PM, Dmitry Osipenko wrote:
>> 23.07.2019 4:52, Sowjanya Komatineni пишет:
>>> On 7/22/19 6:41 PM, Dmitry Osipenko wrote:
>>>> 23.07.2019 4:08, Dmitry Osipenko пишет:
>>>>> 23.07.2019 3:58, Dmitry Osipenko пишет:
>>>>>> 21.07.2019 22:40, Sowjanya Komatineni пишет:
>>>>>>> This patch implements PMC wakeup sequence for Tegra210 and defines
>>>>>>> common used RTC alarm wake event.
>>>>>>>
>>>>>>> Signed-off-by: Sowjanya Komatineni <skomatineni@...dia.com>
>>>>>>> ---
>>>>>>> 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
>>>>>>> #define DPD_SAMPLE 0x020
>>>>>>> #define DPD_SAMPLE_ENABLE BIT(0)
>>>>>>> @@ -87,6 +93,11 @@
>>>>>>> #define PMC_SCRATCH41 0x140
>>>>>>> +#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 = {
>>>>>>> .alloc = tegra_pmc_irq_alloc,
>>>>>>> };
>>>>>>> +static int tegra210_pmc_irq_set_wake(struct irq_data *data,
>>>>>>> unsigned int on)
>>>>>>> +{
>>>>>>> + struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>>>>>>> + unsigned int offset, bit;
>>>>>>> + u32 value;
>>>>>>> +
>>>>>>> + if (data->hwirq == ULONG_MAX)
>>>>>>> + return 0;
>>>>>>> +
>>>>>>> + offset = data->hwirq / 32;
>>>>>>> + bit = data->hwirq % 32;
>>>>>>> +
>>>>>>> + /*
>>>>>>> + * Latch wakeups to SW_WAKE_STATUS register to capture events
>>>>>>> + * that would not make it into wakeup event register during
>>>>>>> LP0 exit.
>>>>>>> + */
>>>>>>> + value = tegra_pmc_readl(pmc, PMC_CNTRL);
>>>>>>> + value |= 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 &= ~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 >= 32)
>>>>>>> + offset = PMC_WAKE2_MASK;
>>>>>>> + else
>>>>>>> + offset = PMC_WAKE_MASK;
>>>>>>> +
>>>>>>> + value = tegra_pmc_readl(pmc, offset);
>>>>>>> +
>>>>>>> + if (on)
>>>>>>> + value |= 1 << bit;
>>>>>>> + else
>>>>>>> + value &= ~(1 << bit);
>>>>>>> +
>>>>>>> + tegra_pmc_writel(pmc, value, offset);
>>>>>> Why the latching is done *before* writing into the WAKE registers?
>>>>>> What
>>>>>> 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 = tegra_pmc_readl(pmc, PMC_CNTRL);
>>>>> value |= 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
>>> design.
>>> 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
> generates on every suspend-resume cycle.
You're saying that PMC "doesn't update SW_WAKE_STATUS" after wake-up,
then I don't quite understand what's the point of disabling the latching
at all.
>>> 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,
>>>>>>> unsigned int on)
>>>>>>> {
>>>>>>> struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>>>>>>> @@ -1954,6 +2014,49 @@ static int
>>>>>>> tegra186_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
>>>>>>> return 0;
>>>>>>> }
>>>>>>> +static int tegra210_pmc_irq_set_type(struct irq_data *data,
>>>>>>> unsigned int type)
>>>>>>> +{
>>>>>>> + struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>>>>>>> + unsigned int offset, bit;
>>>>>>> + u32 value;
>>>>>>> +
>>>>>>> + if (data->hwirq == ULONG_MAX)
>>>>>>> + return 0;
>>>>>>> +
>>>>>>> + offset = data->hwirq / 32;
>>>>>>> + bit = data->hwirq % 32;
>>>>>>> +
>>>>>>> + if (data->hwirq >= 32)
>>>>>>> + offset = PMC_WAKE2_LEVEL;
>>>>>>> + else
>>>>>>> + offset = PMC_WAKE_LEVEL;
>>>>>>> +
>>>>>>> + value = tegra_pmc_readl(pmc, offset);
>>>>>>> +
>>>>>>> + switch (type) {
>>>>>>> + case IRQ_TYPE_EDGE_RISING:
>>>>>>> + case IRQ_TYPE_LEVEL_HIGH:
>>>>>>> + value |= 1 << bit;
>>>>>>> + break;
>>>>>>> +
>>>>>>> + case IRQ_TYPE_EDGE_FALLING:
>>>>>>> + case IRQ_TYPE_LEVEL_LOW:
>>>>>>> + value &= ~(1 << bit);
>>>>>>> + break;
>>>>>>> +
>>>>>>> + case IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING:
>>>>>>> + value ^= 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]
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