[U-Boot] [PATCH v2 5/8] spi: cadence_qspi: add reset handling

[Marek Vasut]

On 2/21/19 11:04 PM, Simon Goldschmidt wrote:
> 
> 
> Am Do., 21. Feb. 2019, 22:56 hat Marek Vasut <marex at denx.de
> <mailto:marex at denx.de>> geschrieben:
> 
>     On 2/21/19 10:43 PM, Simon Goldschmidt wrote:
>     > This adds reset handling to the cadence qspi driver.
>     >
>     > For backwards compatibility, only a warning is printed when failing to
>     > get reset handles.
>     >
>     > Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com
>     <mailto:simon.k.r.goldschmidt at gmail.com>>
>     > ---
>     >
>     > Changes in v2:
>     > - add .remove callback to release the resets
>     >
>     >  drivers/spi/cadence_qspi.c | 16 ++++++++++++++++
>     >  drivers/spi/cadence_qspi.h |  4 ++++
>     >  2 files changed, 20 insertions(+)
>     >
>     > diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
>     > index 11fce9c4fe..3bfa0201c4 100644
>     > --- a/drivers/spi/cadence_qspi.c
>     > +++ b/drivers/spi/cadence_qspi.c
>     > @@ -8,6 +8,7 @@
>     >  #include <dm.h>
>     >  #include <fdtdec.h>
>     >  #include <malloc.h>
>     > +#include <reset.h>
>     >  #include <spi.h>
>     >  #include <linux/errno.h>
>     >  #include "cadence_qspi.h"
>     > @@ -154,10 +155,17 @@ static int cadence_spi_probe(struct udevice
>     *bus)
>     >  {
>     >       struct cadence_spi_platdata *plat = bus->platdata;
>     >       struct cadence_spi_priv *priv = dev_get_priv(bus);
>     > +     int ret;
>     > 
>     >       priv->regbase = plat->regbase;
>     >       priv->ahbbase = plat->ahbbase;
>     > 
>     > +     ret = reset_get_bulk(bus, &priv->resets);
>     > +     if (ret)
>     > +             dev_warn(bus, "Can't get reset: %d\n", ret);
>     > +     else
>     > +             reset_deassert_bulk(&priv->resets);
>     > +
>     >       if (!priv->qspi_is_init) {
>     >               cadence_qspi_apb_controller_init(plat);
>     >               priv->qspi_is_init = 1;
>     > @@ -166,6 +174,13 @@ static int cadence_spi_probe(struct udevice *bus)
>     >       return 0;
>     >  }
>     > 
>     > +static int cadence_spi_remove(struct udevice *dev)
>     > +{
>     > +     struct cadence_spi_priv *priv = dev_get_priv(dev);
>     > +
>     > +     return reset_release_bulk(&priv->resets);
>     > +}
>     > +
>     >  static int cadence_spi_set_mode(struct udevice *bus, uint mode)
>     >  {
>     >       struct cadence_spi_priv *priv = dev_get_priv(bus);
>     > @@ -342,4 +357,5 @@ U_BOOT_DRIVER(cadence_spi) = {
>     >       .platdata_auto_alloc_size = sizeof(struct cadence_spi_platdata),
>     >       .priv_auto_alloc_size = sizeof(struct cadence_spi_priv),
>     >       .probe = cadence_spi_probe,
>     > +     .remove = cadence_spi_remove,
> 
>     .remove() only ever gets executed for drivers setting DM_FLAG_OS_PREPARE
>     flag. Fix this in the other drivers too.
> 
> 
> Ehrm, I haven't checked, but is this common practice? Why doesn't it
> always get called?

That's how the code behaves. Probably to speed up booting the kernel on
devices which don't need to be torn down.

-- 
Best regards,
Marek Vasut