[v2,2/3] mmc: sdhci: add quirks for be to le byte swapping
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Message ID 20190616204823.32758-2-angelo@sysam.it
State New
Headers show
Series
  • [v2,1/3] mmc: add Coldfire esdhc support
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Commit Message

Angelo Dureghello June 16, 2019, 8:48 p.m. UTC
Some controller as the ColdFire eshdc may require an endianness
byte swap, because DMA read endianness is not configurable.

Signed-off-by: Angelo Dureghello <angelo@sysam.it>
---
 drivers/mmc/host/sdhci.c | 19 +++++++++++++++++++
 drivers/mmc/host/sdhci.h |  7 +++++++
 2 files changed, 26 insertions(+)

Comments

Adrian Hunter July 2, 2019, 9:10 a.m. UTC | #1
On 16/06/19 11:48 PM, Angelo Dureghello wrote:
> Some controller as the ColdFire eshdc may require an endianness
> byte swap, because DMA read endianness is not configurable.

I would prefer something more generic, like adding another callback
for ->request_done() e.g.


diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index f56ae6f153d4..a63e528cb885 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2729,7 +2729,10 @@ static bool sdhci_request_done(struct sdhci_host *host)
 
 	spin_unlock_irqrestore(&host->lock, flags);
 
-	mmc_request_done(host->mmc, mrq);
+	if (host->ops->request_done)
+		host->ops->request_done(host, mrq);
+	else
+		mmc_request_done(host->mmc, mrq);
 
 	return false;
 }


Then you can use the ->request_done() callback to iterate over the data->sg
and make byte-swaps as needed.

> 
> Signed-off-by: Angelo Dureghello <angelo@sysam.it>
> ---
>  drivers/mmc/host/sdhci.c | 19 +++++++++++++++++++
>  drivers/mmc/host/sdhci.h |  7 +++++++
>  2 files changed, 26 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 59acf8e3331e..f56ae6f153d4 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2600,6 +2600,18 @@ static const struct mmc_host_ops sdhci_ops = {
>  	.card_busy	= sdhci_card_busy,
>  };
>  
> +static void sdhci_be_to_le(char *buff, u32 length)
> +{
> +	int i, size = length >> 2;
> +	u32 *buffer = (u32 *)buff;
> +	u32 temp;
> +
> +	for (i = 0; i < size; i++) {
> +		temp = *buffer;
> +		*buffer++ = __le32_to_cpu(temp);
> +	}
> +}
> +
>  /*****************************************************************************\
>   *                                                                           *
>   * Request done                                                              *
> @@ -2655,6 +2667,13 @@ static bool sdhci_request_done(struct sdhci_host *host)
>  						host->bounce_addr,
>  						host->bounce_buffer_size,
>  						DMA_FROM_DEVICE);
> +
> +					if (host->quirks2 &
> +					    SDHCI_QUIRK2_USE_32BIT_BE_DMA_SWAP)
> +						sdhci_be_to_le(
> +							host->bounce_buffer,
> +							length);
> +
>  					sg_copy_from_buffer(data->sg,
>  						data->sg_len,
>  						host->bounce_buffer,
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 199712e7adbb..be08ff1a8c6f 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -482,6 +482,13 @@ struct sdhci_host {
>   */
>  #define SDHCI_QUIRK2_USE_32BIT_BLK_CNT			(1<<18)
>  
> +/*
> + * On some architectures, as ColdFire/m68k, native endianness is big endian,
> + * and the dma buffer is filled in big endian order only (no other options).
> + * So, a swap is needed for these specific cases.
> + */
> +#define SDHCI_QUIRK2_USE_32BIT_BE_DMA_SWAP		(1<<19)
> +
>  	int irq;		/* Device IRQ */
>  	void __iomem *ioaddr;	/* Mapped address */
>  	char *bounce_buffer;	/* For packing SDMA reads/writes */
>
Angelo Dureghello July 6, 2019, 10 a.m. UTC | #2
Hi Adrian,

thanks for the feedbacks.

On Tue, Jul 02, 2019 at 12:10:44PM +0300, Adrian Hunter wrote:
> On 16/06/19 11:48 PM, Angelo Dureghello wrote:
> > Some controller as the ColdFire eshdc may require an endianness
> > byte swap, because DMA read endianness is not configurable.
> 
> I would prefer something more generic, like adding another callback
> for ->request_done() e.g.
> 
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index f56ae6f153d4..a63e528cb885 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2729,7 +2729,10 @@ static bool sdhci_request_done(struct sdhci_host *host)
>  
>  	spin_unlock_irqrestore(&host->lock, flags);
>  
> -	mmc_request_done(host->mmc, mrq);
> +	if (host->ops->request_done)
> +		host->ops->request_done(host, mrq);
> +	else
> +		mmc_request_done(host->mmc, mrq);
>  
>  	return false;
>  }
> 
> 
> Then you can use the ->request_done() callback to iterate over the data->sg
> and make byte-swaps as needed.
> 
Ok, good to know, will try.

> > 
> > Signed-off-by: Angelo Dureghello <angelo@sysam.it>
> > ---
> >  drivers/mmc/host/sdhci.c | 19 +++++++++++++++++++
> >  drivers/mmc/host/sdhci.h |  7 +++++++
> >  2 files changed, 26 insertions(+)
> > 
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index 59acf8e3331e..f56ae6f153d4 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -2600,6 +2600,18 @@ static const struct mmc_host_ops sdhci_ops = {
> >  	.card_busy	= sdhci_card_busy,
> >  };
> >  
> > +static void sdhci_be_to_le(char *buff, u32 length)
> > +{
> > +	int i, size = length >> 2;
> > +	u32 *buffer = (u32 *)buff;
> > +	u32 temp;
> > +
> > +	for (i = 0; i < size; i++) {
> > +		temp = *buffer;
> > +		*buffer++ = __le32_to_cpu(temp);
> > +	}
> > +}
> > +
> >  /*****************************************************************************\
> >   *                                                                           *
> >   * Request done                                                              *
> > @@ -2655,6 +2667,13 @@ static bool sdhci_request_done(struct sdhci_host *host)
> >  						host->bounce_addr,
> >  						host->bounce_buffer_size,
> >  						DMA_FROM_DEVICE);
> > +
> > +					if (host->quirks2 &
> > +					    SDHCI_QUIRK2_USE_32BIT_BE_DMA_SWAP)
> > +						sdhci_be_to_le(
> > +							host->bounce_buffer,
> > +							length);
> > +
> >  					sg_copy_from_buffer(data->sg,
> >  						data->sg_len,
> >  						host->bounce_buffer,
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index 199712e7adbb..be08ff1a8c6f 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -482,6 +482,13 @@ struct sdhci_host {
> >   */
> >  #define SDHCI_QUIRK2_USE_32BIT_BLK_CNT			(1<<18)
> >  
> > +/*
> > + * On some architectures, as ColdFire/m68k, native endianness is big endian,
> > + * and the dma buffer is filled in big endian order only (no other options).
> > + * So, a swap is needed for these specific cases.
> > + */
> > +#define SDHCI_QUIRK2_USE_32BIT_BE_DMA_SWAP		(1<<19)
> > +
> >  	int irq;		/* Device IRQ */
> >  	void __iomem *ioaddr;	/* Mapped address */
> >  	char *bounce_buffer;	/* For packing SDMA reads/writes */
> > 
> 

Reagrds,
Angelo

Patch
diff mbox series

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 59acf8e3331e..f56ae6f153d4 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2600,6 +2600,18 @@  static const struct mmc_host_ops sdhci_ops = {
 	.card_busy	= sdhci_card_busy,
 };
 
+static void sdhci_be_to_le(char *buff, u32 length)
+{
+	int i, size = length >> 2;
+	u32 *buffer = (u32 *)buff;
+	u32 temp;
+
+	for (i = 0; i < size; i++) {
+		temp = *buffer;
+		*buffer++ = __le32_to_cpu(temp);
+	}
+}
+
 /*****************************************************************************\
  *                                                                           *
  * Request done                                                              *
@@ -2655,6 +2667,13 @@  static bool sdhci_request_done(struct sdhci_host *host)
 						host->bounce_addr,
 						host->bounce_buffer_size,
 						DMA_FROM_DEVICE);
+
+					if (host->quirks2 &
+					    SDHCI_QUIRK2_USE_32BIT_BE_DMA_SWAP)
+						sdhci_be_to_le(
+							host->bounce_buffer,
+							length);
+
 					sg_copy_from_buffer(data->sg,
 						data->sg_len,
 						host->bounce_buffer,
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 199712e7adbb..be08ff1a8c6f 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -482,6 +482,13 @@  struct sdhci_host {
  */
 #define SDHCI_QUIRK2_USE_32BIT_BLK_CNT			(1<<18)
 
+/*
+ * On some architectures, as ColdFire/m68k, native endianness is big endian,
+ * and the dma buffer is filled in big endian order only (no other options).
+ * So, a swap is needed for these specific cases.
+ */
+#define SDHCI_QUIRK2_USE_32BIT_BE_DMA_SWAP		(1<<19)
+
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */
 	char *bounce_buffer;	/* For packing SDMA reads/writes */