Re: [PATCH] spi: set right CS polarity depend on gpiolib

[乱石]

Hi,
在 2021/5/7 23:30, Mark Brown 写道:
> On Fri, May 07, 2021 at 10:51:17PM +0800, Liguang Zhang wrote:
> > After a kernel upgrade from 4.19 to 5.10, we found that tpm flow control
> > always causes TIMEOUT which caused by wrong CS polarity setting depend
> > on gpiolib.
> >   			if (spi->cs_gpiod)
> >   				/* polarity handled by gpiolib */
> > -				gpiod_set_value_cansleep(spi->cs_gpiod, activate);
> > +				gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
> Whatever is going on here it doesn't seem likely that this is a problem
> in the SPI core given the widespread use of gpiod based chip selects -
> can you provide more explanation of what you're seeing here, how is the
> chip select configured, what is the hardware expectation and what
> actually ends up happening?

The arm platform is  kunpeng-920, detail dsdt information here:

        Device (SPI0)
        {
            Name (_HID, "HISI0173")  // _HID: Hardware ID
            Name (_ADR, Zero)  // _ADR: Address
            Name (_UID, Zero)  // _UID: Unique ID
            Name (RBUF, ResourceTemplate ()
            {
                GpioIo (Exclusive, PullUp, 0x0000, 0x0000, 
IoRestrictionNone,
                    "\\_SB.GPO1", 0x00, ResourceConsumer, ,
                    )
                    {   // Pin list
                        0x0006
                    }
                QWordMemory (ResourceConsumer, PosDecode, MinFixed, 
MaxFixed, NonCacheable, ReadWrite,
                    0x0000000000000000, // Granularity
                    0x00000002011A0000, // Range Minimum
                    0x00000002011AFFFF, // Range Maximum
                    0x0000000000000000, // Translation Offset
                    0x0000000000010000, // Length
                    ,, , AddressRangeMemory, TypeStatic)
                Interrupt (ResourceConsumer, Level, ActiveHigh, 
Exclusive, ,, )
                {
                    0x000001EB,
                }
            })
            Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource 
Settings
            {
                Return (RBUF) /* \_SB_.SPI0.RBUF */
            }

            Name (_DSD, Package (0x02)  // _DSD: Device-Specific Data
            {
                ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301") /* 
Device Properties for _DSD */,
                Package (0x03)
                {
                    Package (0x02)
                    {
                        "reg-io-width",
                        0x04
                    },

                    Package (0x02)
                    {
                        "num-cs",
                        One
                    },

                    Package (0x02)
                    {
                        "cs-gpios",
                        Package (0x04)
                        {
                            SPI0,
                            Zero,
                            Zero,
                            Zero
                        }
                    }
                }
            })
        }

        Scope (SPI0)
        {
            Device (TPM)
            {
                Name (_ADR, Zero)  // _ADR: Address
                Name (_CID, Package (0x01)  // _CID: Compatible ID
                {
                    "SMO0768"
                })
                Name (_UID, Zero)  // _UID: Unique ID
                Name (_DSD, Package (0x02)  // _DSD: Device-Specific Data
                {
                    ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301") /* 
Device Properties for _DSD */,
                    Package (0x00){}
                })
                Method (_CRS, 0, NotSerialized)  // _CRS: Current 
Resource Settings
                {
                    Name (RBUF, ResourceTemplate ()
                    {
                        SpiSerialBusV2 (0x0000, PolarityLow, 
FourWireMode, 0x08,
                            ControllerInitiated, 0x000F4240, 
ClockPolarityLow,
                            ClockPhaseFirst, "\\_SB.SPI0",
                            0x00, ResourceConsumer, , Exclusive,
                            )
                    })
                    Return (RBUF) /* \_SB_.SPI0.TPM_._CRS.RBUF */
                }

                Method (_STA, 0, NotSerialized)  // _STA: Status
                {
                    If ((TPEN == One))
                    {
                        Return (0x0F)
                    }
                    Else
                    {
                        Return (Zero)
                    }
                }
            }
        }
    }


The problem I meet is:

   tpm_tis_spi_init

       tpm_tis_core_init

            wait_startup     // Timeout is occured, appear every time.

If the modification below done, probe succeed.

gpiod_set_value_cansleep(spi->cs_gpiod, !enable)