On 7 May 2014 12:06, Ludovic Desroches <ludovic.desroches@xxxxxxxxx> 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@xxxxxxxxx>
> ---
>
> 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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