Re: [RFC PATCH v3 05/16] ARM: edma: add AM33XX crossbar event support

From: Matt Porter
Date: Thu Jan 10 2013 - 17:49:51 EST


On Sun, Oct 28, 2012 at 04:41:24PM +0530, Sekhar Nori wrote:
> On 10/18/2012 6:56 PM, Matt Porter wrote:
> > Adds support for the per-EDMA channel event mux. This is required
> > for any peripherals using DMA crossbar mapped events.
> >
> > Signed-off-by: Matt Porter <mporter@xxxxxx>
> > ---
> > arch/arm/common/edma.c | 63 +++++++++++++++++++++++++++++++++++-
> > include/linux/platform_data/edma.h | 1 +
> > 2 files changed, 63 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
> > index 6d2a590..b761b7a 100644
> > --- a/arch/arm/common/edma.c
> > +++ b/arch/arm/common/edma.c
> > @@ -1425,6 +1425,53 @@ static int edma_of_read_u32_to_s16_array(const struct device_node *np,
> > return 0;
> > }
> >
> > +static int edma_xbar_event_map(struct device *dev,
> > + struct device_node *node,
> > + struct edma_soc_info *pdata, int len)
> > +{
> > + int ret = 0;
> > + int i;
> > + struct resource res;
> > + void *xbar;
> > + s16 (*xbar_chans)[2];
> > + u32 shift, offset, mux;
> > +
> > + xbar_chans = devm_kzalloc(dev,
> > + len/sizeof(s16) + 2*sizeof(s16),
> > + GFP_KERNEL);
> > + if (!xbar_chans)
> > + return -ENOMEM;
> > +
> > + ret = of_address_to_resource(node, 1, &res);
> > + if (IS_ERR_VALUE(ret))
> > + return -EIO;
> > +
> > + xbar = devm_ioremap(dev, res.start, resource_size(&res));
> > + if (!xbar)
> > + return -EIO;
>
> -ENOMEM is more appropiate for ioremap failures.

Fixed in v4.

>
> > +
> > + ret = edma_of_read_u32_to_s16_array(node,
> > + "ti,edma-xbar-event-map",
> > + (s16 *)xbar_chans,
> > + len/sizeof(u32));
> > + if (IS_ERR_VALUE(ret))
> > + return -EIO;
> > +
> > + for (i = 0; xbar_chans[i][0] != -1; i++) {
> > + shift = (xbar_chans[i][1] % 4) * 8;
> > + offset = xbar_chans[i][1] >> 2;
> > + offset <<= 2;
> > + mux = __raw_readl((void *)((u32)xbar + offset));
>
> Dont use __raw* variants of io accessors. There will be ordering issues
> on ARMv7.

Fixed in v4.

>
> > + mux &= (~(0xff << shift));
> > + mux |= (xbar_chans[i][0] << shift);
>
> Unnecessary parens above.

Fixed in v4.

>
> > + __raw_writel(mux, (void *)((u32)xbar + offset));
> > + }
> > +
> > + pdata->xbar_chans = xbar_chans;
> > +
> > + return 0;
> > +}
> > +
> > static int edma_of_parse_dt(struct device *dev,
> > struct device_node *node,
> > struct edma_soc_info *pdata)
> > @@ -1453,7 +1500,6 @@ static int edma_of_parse_dt(struct device *dev,
> > pdata->n_slot = value;
> >
> > pdata->n_cc = 1;
> > - /* This is unused */
>
> The comment should have not been part of 4/16?

Correct. I moved the change to the correct patch in v4.

>
> Thanks,
> Sekhar
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