Re: [PATCH V3 02/17] pinctrl: tegra: add suspend and resume support

From: Dmitry Osipenko
Date: Wed Jun 19 2019 - 04:45:57 EST

19.06.2019 11:31, Thierry Reding ÐÐÑÐÑ:
> On Tue, Jun 18, 2019 at 11:00:05PM +0300, Dmitry Osipenko wrote:
>> 18.06.2019 20:34, Sowjanya Komatineni ÐÐÑÐÑ:
>>>
>>> On 6/18/19 9:50 AM, Sowjanya Komatineni wrote:
>>>>
>>>> On 6/18/19 8:41 AM, Stephen Warren wrote:
>>>>> On 6/18/19 3:30 AM, Dmitry Osipenko wrote:
>>>>>> 18.06.2019 12:22, Dmitry Osipenko ÐÐÑÐÑ:
>>>>>>> 18.06.2019 10:46, Sowjanya Komatineni ÐÐÑÐÑ:
>>>>>>>> This patch adds suspend and resume support for Tegra pinctrl driver
>>>>>>>> and registers them to syscore so the pinmux settings are restored
>>>>>>>> before the devices resume.
>>>>>>>>
>>>>>>>> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
>>>>>>>> ---
>>>>>>>> Â drivers/pinctrl/tegra/pinctrl-tegra.cÂÂÂ | 62 ++++++++++++++++++++++++++++++++
>>>>>>>> Â drivers/pinctrl/tegra/pinctrl-tegra.hÂÂÂ |Â 5 +++
>>>>>>>> Â drivers/pinctrl/tegra/pinctrl-tegra114.c |Â 1 +
>>>>>>>> Â drivers/pinctrl/tegra/pinctrl-tegra124.c |Â 1 +
>>>>>>>>  drivers/pinctrl/tegra/pinctrl-tegra20.c | 1 +
>>>>>>>> Â drivers/pinctrl/tegra/pinctrl-tegra210.c | 13 +++++++
>>>>>>>>  drivers/pinctrl/tegra/pinctrl-tegra30.c | 1 +
>>>>>>>> Â 7 files changed, 84 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.c
>>>>>>>> b/drivers/pinctrl/tegra/pinctrl-tegra.c
>>>>>>>> index 34596b246578..ceced30d8bd1 100644
>>>>>>>> --- a/drivers/pinctrl/tegra/pinctrl-tegra.c
>>>>>>>> +++ b/drivers/pinctrl/tegra/pinctrl-tegra.c
>>>>>>>> @@ -20,11 +20,16 @@
>>>>>>>> Â #include <linux/pinctrl/pinmux.h>
>>>>>>>> Â #include <linux/pinctrl/pinconf.h>
>>>>>>>> Â #include <linux/slab.h>
>>>>>>>> +#include <linux/syscore_ops.h>
>>>>>>>> Â Â #include "../core.h"
>>>>>>>> Â #include "../pinctrl-utils.h"
>>>>>>>> Â #include "pinctrl-tegra.h"
>>>>>>>> Â +#define EMMC2_PAD_CFGPADCTRL_0ÂÂÂÂÂÂÂÂÂÂÂ 0x1c8
>>>>>>>> +#define EMMC4_PAD_CFGPADCTRL_0ÂÂÂÂÂÂÂÂÂÂÂ 0x1e0
>>>>>>>> +#define EMMC_DPD_PARKINGÂÂÂÂÂÂÂÂÂÂÂ (0x1fff << 14)
>>>>>>>> +
>>>>>>>> Â static inline u32 pmx_readl(struct tegra_pmx *pmx, u32 bank, u32 reg)
>>>>>>>> Â {
>>>>>>>> ÂÂÂÂÂ return readl(pmx->regs[bank] + reg);
>>>>>>>> @@ -619,6 +624,48 @@ static void tegra_pinctrl_clear_parked_bits(struct tegra_pmx *pmx)
>>>>>>>> ÂÂÂÂÂÂÂÂÂÂÂÂÂ pmx_writel(pmx, val, g->mux_bank, g->mux_reg);
>>>>>>>> ÂÂÂÂÂÂÂÂÂ }
>>>>>>>> ÂÂÂÂÂ }
>>>>>>>> +
>>>>>>>> +ÂÂÂ if (pmx->soc->has_park_padcfg) {
>>>>>>>> +ÂÂÂÂÂÂÂ val = pmx_readl(pmx, 0, EMMC2_PAD_CFGPADCTRL_0);
>>>>>>>> +ÂÂÂÂÂÂÂ val &= ~EMMC_DPD_PARKING;
>>>>>>>> +ÂÂÂÂÂÂÂ pmx_writel(pmx, val, 0, EMMC2_PAD_CFGPADCTRL_0);
>>>>>>>> +
>>>>>>>> +ÂÂÂÂÂÂÂ val = pmx_readl(pmx, 0, EMMC4_PAD_CFGPADCTRL_0);
>>>>>>>> +ÂÂÂÂÂÂÂ val &= ~EMMC_DPD_PARKING;
>>>>>>>> +ÂÂÂÂÂÂÂ pmx_writel(pmx, val, 0, EMMC4_PAD_CFGPADCTRL_0);
>>>>>>>> +ÂÂÂ }
>>>>>>>> +}
>>>>>>>
>>>>>>> Is there any reason why parked_bit can't be changed to parked_bitmask like I was
>>>>>>> asking in a comment to v2?
>>>>>>>
>>>>>>> I suppose that it's more preferable to keep pinctrl-tegra.c platform-agnostic for
>>>>>>> consistency when possible, hence adding platform specifics here should be discouraged.
>>>>>>> And then the parked_bitmask will also result in a proper hardware description in the code.
>>>>>>>
>>>>>>
>>>>>> I'm now also vaguely recalling that Stephen Warren had some kind of a "code generator"
>>>>>> for the pinctrl drivers. So I guess all those tables were auto-generated initially.
>>>>>>
>>>>>> Stephen, maybe you could adjust the generator to take into account the bitmask (of
>>>>>> course if that's a part of the generated code) and then re-gen it all for Sowjanya?
>>>>>
>>>>> https://github.com/NVIDIA/tegra-pinmux-scripts holds the scripts that generate
>>>>> tegra-pinctrlNNN.c. See soc-to-kernel-pinctrl-driver.py. IIRC, tegra-pinctrl.c (the core
>>>>> file) isn't auto-generated. Sowjanya is welcome to send a patch to that repo if the code
>>>>> needs to be updated.
>>>>
>>>>
>>>> Hi Dmitry,
>>>>
>>>> Just want to be clear on my understanding of your request.
>>>>
>>>> "change parked_bit to parked_bitmask" are you requested to change parked_bit of PINGROUP
>>>> and DRV_PINGROUP to use bitmask value rather than bit position inorder to have parked bit
>>>> configuration for EMMC PADs as well to happen by masking rather than checking for
>>>> existence of parked_bit?
>>>>
>>>> Trying to understand the reason/benefit for changing parked_bit to parked_bitmask.
>>> Also, Park bits in CFGPAD registers are not common for all CFGPAD registers. Park bits are
>>> available only for EMMC and also those bits are used for something else on other CFGPAD
>>> registers so bitmask can't be common and this also need an update to DRV_PINGROUP macro args
>>> just only to handle EMMC parked_bitmask. So not sure of the benefit in using bitmask rather
>>
>> Hi Sowjanya,
>>
>> The main motivation is to describe hardware properly in the drivers. Why to make a
>> hacky-looking workaround while you can make things properly? Especially if that doesn't take
>> much effort.
>>
>> Stephen, thank you very much for the pointer to the script. Looks like it should be easy to
>> modify the script accordingly to the required change.
>>
>> Sowjanya, below is a draft of the change that I'm suggesting. I see this as two separate
>> patches: first converts drivers to use parked_bitmask, second adds suspend-resume support.
>>
>> Please note that in the end it's up to you and Tegra/PINCTRL maintainers to decide if this
>> is a worthwhile change that I'm suggesting. In my opinion it is much better to have a
>> generic solution rather than to have a special quirk solely for T210.
>>
>> diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.c b/drivers/pinctrl/tegra/pinctrl-tegra.c
>> index 34596b246578..4150da74bd44 100644
>> --- a/drivers/pinctrl/tegra/pinctrl-tegra.c
>> +++ b/drivers/pinctrl/tegra/pinctrl-tegra.c
>> @@ -613,9 +613,9 @@ static void tegra_pinctrl_clear_parked_bits(struct tegra_pmx *pmx)
>>
>> for (i = 0; i < pmx->soc->ngroups; ++i) {
>> g = &pmx->soc->groups[i];
>> - if (g->parked_bit >= 0) {
>> + if (g->parked_bitmask != -1) {
>> val = pmx_readl(pmx, g->mux_bank, g->mux_reg);
>> - val &= ~(1 << g->parked_bit);
>> + val &= ~g->parked_bitmask;
>> pmx_writel(pmx, val, g->mux_bank, g->mux_reg);
>> }
>> }
>> diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.h b/drivers/pinctrl/tegra/pinctrl-tegra.h
>> index 287702660783..875eb7a1d838 100644
>> --- a/drivers/pinctrl/tegra/pinctrl-tegra.h
>> +++ b/drivers/pinctrl/tegra/pinctrl-tegra.h
>> @@ -96,7 +96,7 @@ struct tegra_function {
>> * @tri_reg: Tri-state register offset.
>> * @tri_bank: Tri-state register bank.
>> * @tri_bit: Tri-state register bit.
>> - * @parked_bit: Parked register bit. -1 if unsupported.
>> + * @parked_bitmask: Parked register bitmask. -1 if unsupported.
>
> If we're already moving to a bitmask, wouldn't it be easier to just make
> 0 the case where it is unsupported?
>
>> * @einput_bit: Enable-input register bit.
>> * @odrain_bit: Open-drain register bit.
>> * @lock_bit: Lock register bit.
>> @@ -146,7 +146,7 @@ struct tegra_pingroup {
>> s32 mux_bit:6;
>> s32 pupd_bit:6;
>> s32 tri_bit:6;
>> - s32 parked_bit:6;
>> + s32 parked_bitmask:26;
>
> If we make parked_bitmask == 0 the case for "unsupported" we could make
> this u32 while at it.
>
>> s32 einput_bit:6;
>> s32 odrain_bit:6;
>> s32 lock_bit:6;
>> diff --git a/drivers/pinctrl/tegra/pinctrl-tegra210.c b/drivers/pinctrl/tegra/pinctrl-tegra210.c
>> index 0b56ad5c9c1c..d2ba13466e06 100644
>> --- a/drivers/pinctrl/tegra/pinctrl-tegra210.c
>> +++ b/drivers/pinctrl/tegra/pinctrl-tegra210.c
>> @@ -1302,7 +1302,7 @@ static struct tegra_function tegra210_functions[] = {
>> .lock_bit = 7, \
>> .ioreset_bit = -1, \
>> .rcv_sel_bit = PINGROUP_BIT_##e_io_hv(10), \
>> - .parked_bit = 5, \
>> + .parked_bitmask = BIT(5), \
>> .hsm_bit = PINGROUP_BIT_##hsm(9), \
>> .schmitt_bit = 12, \
>> .drvtype_bit = PINGROUP_BIT_##drvtype(13), \
>> @@ -1320,7 +1320,7 @@ static struct tegra_function tegra210_functions[] = {
>> }
>>
>> #define DRV_PINGROUP(pg_name, r, drvdn_b, drvdn_w, drvup_b, drvup_w, \
>> - slwr_b, slwr_w, slwf_b, slwf_w) \
>> + slwr_b, slwr_w, slwf_b, slwf_w, prk_mask) \
>> { \
>> .name = "drive_" #pg_name, \
>> .pins = drive_##pg_name##_pins, \
>> @@ -1335,7 +1335,7 @@ static struct tegra_function tegra210_functions[] = {
>> .rcv_sel_bit = -1, \
>> .drv_reg = DRV_PINGROUP_REG(r), \
>> .drv_bank = 0, \
>> - .parked_bit = -1, \
>> + .parked_bitmask = prk_mask, \
>> .hsm_bit = -1, \
>> .schmitt_bit = -1, \
>> .lpmd_bit = -1, \
>> @@ -1516,31 +1516,31 @@ static const struct tegra_pingroup tegra210_groups[] = {
>> PINGROUP(pz5, SOC, RSVD1, RSVD2, RSVD3, 0x3290, N, N, N,
>> -1, -1, -1, -1, -1, -1, -1, -1, -1),
>>
>> /* pg_name, r, drvdn_b, drvdn_w, drvup_b, drvup_w, slwr_b, slwr_w, slwf_b, slwf_w */
>> - DRV_PINGROUP(pa6, 0x9c0, 12, 5, 20, 5, -1, -1, -1, -1),
>> - DRV_PINGROUP(pcc7, 0x9c4, 12, 5, 20, 5, -1, -1, -1, -1),
>> - DRV_PINGROUP(pe6, 0x9c8, 12, 5, 20, 5, -1, -1, -1, -1),
>> - DRV_PINGROUP(pe7, 0x9cc, 12, 5, 20, 5, -1, -1, -1, -1),
>> - DRV_PINGROUP(ph6, 0x9d0, 12, 5, 20, 5, -1, -1, -1, -1),
>> - DRV_PINGROUP(pk0, 0x9d4, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pk1, 0x9d8, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pk2, 0x9dc, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pk3, 0x9e0, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pk4, 0x9e4, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pk5, 0x9e8, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pk6, 0x9ec, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pk7, 0x9f0, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pl0, 0x9f4, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pl1, 0x9f8, -1, -1, -1, -1, 28, 2, 30, 2),
>> - DRV_PINGROUP(pz0, 0x9fc, 12, 7, 20, 7, -1, -1, -1, -1),
>> - DRV_PINGROUP(pz1, 0xa00, 12, 7, 20, 7, -1, -1, -1, -1),
>> - DRV_PINGROUP(pz2, 0xa04, 12, 7, 20, 7, -1, -1, -1, -1),
>> - DRV_PINGROUP(pz3, 0xa08, 12, 7, 20, 7, -1, -1, -1, -1),
>> - DRV_PINGROUP(pz4, 0xa0c, 12, 7, 20, 7, -1, -1, -1, -1),
>> - DRV_PINGROUP(pz5, 0xa10, 12, 7, 20, 7, -1, -1, -1, -1),
>> - DRV_PINGROUP(sdmmc1, 0xa98, 12, 7, 20, 7, 28, 2, 30, 2),
>> - DRV_PINGROUP(sdmmc2, 0xa9c, 2, 6, 8, 6, 28, 2, 30, 2),
>> - DRV_PINGROUP(sdmmc3, 0xab0, 12, 7, 20, 7, 28, 2, 30, 2),
>> - DRV_PINGROUP(sdmmc4, 0xab4, 2, 6, 8, 6, 28, 2, 30, 2),
>> + DRV_PINGROUP(pa6, 0x9c0, 12, 5, 20, 5, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(pcc7, 0x9c4, 12, 5, 20, 5, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(pe6, 0x9c8, 12, 5, 20, 5, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(pe7, 0x9cc, 12, 5, 20, 5, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(ph6, 0x9d0, 12, 5, 20, 5, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(pk0, 0x9d4, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pk1, 0x9d8, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pk2, 0x9dc, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pk3, 0x9e0, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pk4, 0x9e4, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pk5, 0x9e8, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pk6, 0x9ec, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pk7, 0x9f0, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pl0, 0x9f4, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pl1, 0x9f8, -1, -1, -1, -1, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(pz0, 0x9fc, 12, 7, 20, 7, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(pz1, 0xa00, 12, 7, 20, 7, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(pz2, 0xa04, 12, 7, 20, 7, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(pz3, 0xa08, 12, 7, 20, 7, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(pz4, 0xa0c, 12, 7, 20, 7, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(pz5, 0xa10, 12, 7, 20, 7, -1, -1, -1, -1, -1),
>> + DRV_PINGROUP(sdmmc1, 0xa98, 12, 7, 20, 7, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(sdmmc2, 0xa9c, 2, 6, 8, 6, 28, 2, 30, 2, 0x7ffc000),
>> + DRV_PINGROUP(sdmmc3, 0xab0, 12, 7, 20, 7, 28, 2, 30, 2, -1),
>> + DRV_PINGROUP(sdmmc4, 0xab4, 2, 6, 8, 6, 28, 2, 30, 2, 0x7ffc000),
>
> Might be worth adding a new DRV_PINGROUP_PARK (or whatever) macro that
> takes the additional parameter. that way we could avoid the extra churn.

Sounds like a very good call! +1