[PATCH rtems-libbsd 1/2] sdhci: Add some workarrounds for i.MX

Christian Mauderer christian.mauderer at embedded-brains.de
Thu Sep 10 13:19:29 UTC 2020


Hello Gedare,

I created a ticket for this in FreeBSD (I really hope I picked the right
way for this). I'll wait whether it needs some adaption and then re-send
an adapted patch for libbsd as soon as I have a version that is accepted
in FreeBSD.

Best regards

Christian

On 10/09/2020 09:05, Christian Mauderer wrote:
> Hello Gedare,
> 
> I'll have to rework some parts (the ones where I checked for the BSP)
> but I'll try.
> 
> Best regards
> 
> Christian>
> On 09/09/2020 17:58, Gedare Bloom wrote:
>> Can this be pushed upstream in a non-RTEMS specific way?
>>
>> On Wed, Sep 9, 2020 at 5:16 AM Christian Mauderer
>> <christian.mauderer at embedded-brains.de> wrote:
>>>
>>> Some bits are in the wrong order. Beneath that, the interrupts can occur
>>> in an unexpected order. The DATA_AVAIL interrupt can occur at the same
>>> time as the DMA interrupt (or slightly before it). With that, the DMA
>>> and PIO interrupt handling doesn't work well together. Beneath that the
>>> DMA interrupt isn't only executed at block ends but also if all data is
>>> transfered. That can lead to problems with the DATA_END interrupt.
>>> Therefore check whether there is really data left to unload.
>>>
>>> Update #3869
>>> ---
>>>  freebsd/sys/dev/sdhci/fsl_sdhci.c | 41 +++++++++++++++++++++++++++++++
>>>  freebsd/sys/dev/sdhci/sdhci.c     | 40 ++++++++++++++++++++++++++++++
>>>  2 files changed, 81 insertions(+)
>>>
>>> diff --git a/freebsd/sys/dev/sdhci/fsl_sdhci.c b/freebsd/sys/dev/sdhci/fsl_sdhci.c
>>> index be3d1de3..acef1c4a 100644
>>> --- a/freebsd/sys/dev/sdhci/fsl_sdhci.c
>>> +++ b/freebsd/sys/dev/sdhci/fsl_sdhci.c
>>> @@ -74,6 +74,9 @@ uint32_t mpc85xx_get_system_clock(void);
>>>  #endif /* __rtems__ */
>>>  #endif
>>>
>>> +#ifndef __rtems__
>>> +#include <bsp.h>
>>> +#endif /* __rtems__ */
>>>  #include <dev/gpio/gpiobusvar.h>
>>>
>>>  #include <dev/ofw/ofw_bus.h>
>>> @@ -168,6 +171,16 @@ struct fsl_sdhci_softc {
>>>  #define         SDHC_PROT_CDSS         (1 << 7)
>>>
>>>  #define        SDHC_SYS_CTRL           0x2c
>>> +#ifdef __rtems__
>>> +
>>> +/*
>>> + * Freescale messed up the INT DMA ERR bit and placed it at bit 28 instead of
>>> + * bit 25 which would be standard.
>>> + */
>>> +#define SDHC_INT_DMAES         (1 << 28)
>>> +
>>> +#define         SDHC_CAN_DO_ADMA2      0x00100000
>>> +#endif /* __rtems__ */
>>>
>>>  /*
>>>   * The clock enable bits exist in different registers for ESDHC vs USDHC, but
>>> @@ -349,6 +362,16 @@ fsl_sdhci_read_4(device_t dev, struct sdhci_slot *slot, bus_size_t off)
>>>                 val32 &= ~SDHCI_CAN_VDD_180;
>>>                 val32 &= ~SDHCI_CAN_DO_SUSPEND;
>>>                 val32 |= SDHCI_CAN_DO_8BITBUS;
>>> +#ifdef __rtems__
>>> +               /*
>>> +                * Freescale signals ADMA2 capability via bit 20 (which would be
>>> +                * ADMA1) instead of 19.
>>> +                */
>>> +               if (val32 & SDHC_CAN_DO_ADMA2) {
>>> +                       val32 &= ~SDHC_CAN_DO_ADMA2;
>>> +                       val32 |= SDHCI_CAN_DO_ADMA2;
>>> +               }
>>> +#endif /* __rtems__ */
>>>                 return (val32);
>>>         }
>>>
>>> @@ -373,6 +396,13 @@ fsl_sdhci_read_4(device_t dev, struct sdhci_slot *slot, bus_size_t off)
>>>          * command with an R1B response, mix it into the hardware status.
>>>          */
>>>         if (off == SDHCI_INT_STATUS) {
>>> +#ifdef __rtems__
>>> +               /* Fix messed up DMA error. */
>>> +               if (val32 & SDHC_INT_DMAES) {
>>> +                       val32 &= ~SDHC_INT_DMAES;
>>> +                       val32 |= SDHCI_INT_ADMAERR;
>>> +               }
>>> +#endif /* __rtems__ */
>>>                 return (val32 | sc->r1bfix_intmask);
>>>         }
>>>
>>> @@ -519,6 +549,15 @@ fsl_sdhci_write_4(device_t dev, struct sdhci_slot *slot, bus_size_t off, uint32_
>>>         if (off == SDHCI_INT_STATUS) {
>>>                 sc->r1bfix_intmask &= ~val;
>>>         }
>>> +#ifdef __rtems__
>>> +       /* Fix messed up DMA error. */
>>> +       if (off == SDHCI_INT_STATUS || off == SDHCI_INT_ENABLE || off == SDHCI_SIGNAL_ENABLE) {
>>> +               if (val & SDHCI_INT_ADMAERR) {
>>> +                       val &= ~SDHCI_INT_ADMAERR;
>>> +                       val |= SDHC_INT_DMAES;
>>> +               }
>>> +       }
>>> +#endif /* __rtems__ */
>>>
>>>         WR4(sc, off, val);
>>>  }
>>> @@ -884,10 +923,12 @@ fsl_sdhci_attach(device_t dev)
>>>
>>>         sc->slot.quirks |= SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK;
>>>
>>> +#if !defined(__rtems__) || !defined(LIBBSP_ARM_IMX_BSP_H)
>>>         /*
>>>          * DMA is not really broken, I just haven't implemented it yet.
>>>          */
>>>         sc->slot.quirks |= SDHCI_QUIRK_BROKEN_DMA;
>>> +#endif /* __rtems__ */
>>>
>>>         /*
>>>          * Set the buffer watermark level to 128 words (512 bytes) for both read
>>> diff --git a/freebsd/sys/dev/sdhci/sdhci.c b/freebsd/sys/dev/sdhci/sdhci.c
>>> index ed6010e8..53d86fe8 100644
>>> --- a/freebsd/sys/dev/sdhci/sdhci.c
>>> +++ b/freebsd/sys/dev/sdhci/sdhci.c
>>> @@ -68,6 +68,9 @@ __FBSDID("$FreeBSD$");
>>>  #include <rtems/bsd/local/sdhci_if.h>
>>>
>>>  #include <rtems/bsd/local/opt_mmccam.h>
>>> +#ifdef __rtems__
>>> +#include <bsp.h>
>>> +#endif /* __rtems__ */
>>>
>>>  SYSCTL_NODE(_hw, OID_AUTO, sdhci, CTLFLAG_RD, 0, "sdhci driver");
>>>
>>> @@ -766,6 +769,17 @@ sdhci_dma_alloc(struct sdhci_slot *slot)
>>>                 else
>>>                         slot->sdma_boundary = SDHCI_BLKSZ_SDMA_BNDRY_512K;
>>>         }
>>> +#ifdef __rtems__
>>> +#if defined(LIBBSP_ARM_IMX_BSP_H)
>>> +       /*
>>> +        * i.MX6ULL doesn't have the SDMA Buffer Boundary bits. Instead the
>>> +        * BLKSIZE is one bit larger and would overlap the Buffer Boundary.
>>> +        * Setting the Buffer Boundary to 4K makes sure that the highest BLKSIZE
>>> +        * bit is always 0.
>>> +        */
>>> +       slot->sdma_boundary = SDHCI_BLKSZ_SDMA_BNDRY_4K;
>>> +#endif
>>> +#endif /* __rtems__ */
>>>         slot->sdma_bbufsz = SDHCI_SDMA_BNDRY_TO_BBUFSZ(slot->sdma_boundary);
>>>
>>>         /*
>>> @@ -1896,6 +1910,10 @@ sdhci_start_data(struct sdhci_slot *slot, const struct mmc_data *data)
>>>                             BUS_DMASYNC_PREWRITE);
>>>                 }
>>>                 WR4(slot, SDHCI_DMA_ADDRESS, slot->paddr);
>>> +#ifdef __rtems__
>>> +               /* Avoid PIO interrupt if we use DMA */
>>> +               slot->intmask &= ~(SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL);
>>> +#endif /* __rtems__ */
>>>                 /*
>>>                  * Interrupt aggregation: Mask border interrupt for the last
>>>                  * bounce buffer and unmask otherwise.
>>> @@ -1932,15 +1950,27 @@ sdhci_finish_data(struct sdhci_slot *slot)
>>>                 WR4(slot, SDHCI_SIGNAL_ENABLE,
>>>                     slot->intmask |= SDHCI_INT_RESPONSE);
>>>         }
>>> +#ifdef __rtems__
>>> +       /* Restore PIO interrupts in case they are necessary elsewhere */
>>> +       if (slot->flags & SDHCI_USE_DMA) {
>>> +               slot->intmask |= SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL;
>>> +       }
>>> +#endif /* __rtems__ */
>>>         /* Unload rest of data from DMA buffer. */
>>>         if (!slot->data_done && (slot->flags & SDHCI_USE_DMA) &&
>>>             slot->curcmd->data != NULL) {
>>>                 if (data->flags & MMC_DATA_READ) {
>>>                         left = data->len - slot->offset;
>>> +#ifdef __rtems__
>>> +                   if (left > 0) {
>>> +#endif /* __rtems__ */
>>>                         bus_dmamap_sync(slot->dmatag, slot->dmamap,
>>>                             BUS_DMASYNC_POSTREAD);
>>>                         memcpy((u_char*)data->data + slot->offset, slot->dmamem,
>>>                             ulmin(left, slot->sdma_bbufsz));
>>> +#ifdef __rtems__
>>> +                   }
>>> +#endif /* __rtems__ */
>>>                 } else
>>>                         bus_dmamap_sync(slot->dmatag, slot->dmamap,
>>>                             BUS_DMASYNC_POSTWRITE);
>>> @@ -2201,8 +2231,15 @@ sdhci_data_irq(struct sdhci_slot *slot, uint32_t intmask)
>>>                             BUS_DMASYNC_POSTWRITE);
>>>                 }
>>>                 /* ... and reload it again. */
>>> +#ifdef __rtems__
>>> +               slot->offset += ulmin(left, sdma_bbufsz);
>>> +#else /* __rtems__ */
>>>                 slot->offset += sdma_bbufsz;
>>> +#endif /* __rtems__ */
>>>                 left = data->len - slot->offset;
>>> +#ifdef __rtems__
>>> +           if (left > 0) {
>>> +#endif /* __rtems__ */
>>>                 if (data->flags & MMC_DATA_READ) {
>>>                         bus_dmamap_sync(slot->dmatag, slot->dmamap,
>>>                             BUS_DMASYNC_PREREAD);
>>> @@ -2222,6 +2259,9 @@ sdhci_data_irq(struct sdhci_slot *slot, uint32_t intmask)
>>>                 }
>>>                 /* Restart DMA. */
>>>                 WR4(slot, SDHCI_DMA_ADDRESS, slot->paddr);
>>> +#ifdef __rtems__
>>> +           }
>>> +#endif /* __rtems__ */
>>>         }
>>>         /* We have got all data. */
>>>         if (intmask & SDHCI_INT_DATA_END) {
>>> --
>>> 2.26.2
>>>
>>> _______________________________________________
>>> devel mailing list
>>> devel at rtems.org
>>> http://lists.rtems.org/mailman/listinfo/devel
> 

-- 
--------------------------------------------
embedded brains GmbH
Herr Christian Mauderer
Dornierstr. 4
D-82178 Puchheim
Germany
email: christian.mauderer at embedded-brains.de
Phone: +49-89-18 94 741 - 18
Fax:   +49-89-18 94 741 - 08
PGP: Public key available on request.

Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.


More information about the devel mailing list