[PATCH RFC] mmc: add slot argument to mmc_of_parse

[Ludovic Desroches]

Hi,

Sorry I was on vacation, I'll send a cleaner patch updating other drivers
this week.

Regards

Ludovic

On Fri, May 23, 2014 at 01:38:06PM +0900, Jaehoon Chung wrote:
> Hi, All.
> 
> This patch is working on progress?
> I want to merge this patch for fixing dw-mmc controller problem.
> 
> If this patch didn't work on progress, i will send the patch based-on this patch.
> 
> Best Regards,
> Jaehoon Chung
> 
> On 05/14/2014 06:53 PM, Ulf Hansson wrote:
> > On 7 May 2014 12:06, Ludovic Desroches <ludovic.desroches at atmel.com> wrote:
> >> Some hosts manage several slots. In these case information such as the bus
> >> width, chip detect and others are into the slot node. So we have to parse
> >> child nodes. If not NULL, slot node will be used instead of the device
> >> node.
> >>
> >> Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
> >> ---
> >>
> >> Hi,
> >>
> >> Since this patch is only a RFC, I have not yet updated drivers using this
> >> function.
> >>
> >> I would like to use mmc_of_parse to reduce code duplication. My issue is that
> >> atmel mci is a bit different from others mci host since it can provide
> >> several slots, so it allocates several mmc hosts. By the way, it is not the
> >> only one.
> >>
> >> When calling mmc_alloc_host, host->parent is set to &pdev->dev. mmc_of_parse
> >> uses host->parent->of_node but in my case settings are in the slot nodes so in
> >> the child nodes. That's why I would like to have a way to tell which node I
> >> want to use.
> > 
> > Seems reasonable, thanks for working on this!
> > 
> >>
> >>
> >> Regards
> >>
> >> Ludovic
> >>
> >>
> >>
> >>  drivers/mmc/core/host.c |    9 +++++++--
> >>  1 file changed, 7 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> >> index fdea825..ed6cea5 100644
> >> --- a/drivers/mmc/core/host.c
> >> +++ b/drivers/mmc/core/host.c
> >> @@ -300,13 +300,15 @@ static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
> >>  /**
> >>   *     mmc_of_parse() - parse host's device-tree node
> >>   *     @host: host whose node should be parsed.
> >> + *     @slot: some devices provide several slots so the node to parse
> >> + *     is not the host one.
> >>   *
> >>   * To keep the rest of the MMC subsystem unaware of whether DT has been
> >>   * used to to instantiate and configure this host instance or not, we
> >>   * parse the properties and set respective generic mmc-host flags and
> >>   * parameters.
> >>   */
> >> -int mmc_of_parse(struct mmc_host *host)
> >> +int mmc_of_parse(struct mmc_host *host, struct device_node *slot)
> >>  {
> >>         struct device_node *np;
> >>         u32 bus_width;
> >> @@ -317,7 +319,10 @@ int mmc_of_parse(struct mmc_host *host)
> >>         if (!host->parent || !host->parent->of_node)
> >>                 return 0;
> >>
> >> -       np = host->parent->of_node;
> >> +       if (slot)
> >> +               np = slot;
> >> +       else
> >> +               np = host->parent->of_node;
> >>
> >>         /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
> >>         if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
> >> --
> >> 1.7.9.5
> >>
> > 
> > How about adding a new API, __mmc_of_parse((struct mmc_host *host,
> > struct device_node *slot)
> > Then let the old API mmc_of_parse() remain as is, but let it call the
> > new API with slot == NULL.
> > 
> > Atmel can then use the new API, but the other drivers can remain as is.
> > 
> > Kind regards
> > Ulf Hansson
> > --
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> > 
> 
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