[U-Boot] [PATCH v5 073/101] spi: ich: Support hardware sequencing

[Bin Meng]

Hi Simon,

On Thu, Nov 28, 2019 at 10:23 AM Simon Glass <sjg at chromium.org> wrote:
>
> Hi Bin,
>
> On Wed, 27 Nov 2019 at 00:16, Bin Meng <bmeng.cn at gmail.com> wrote:
> >
> > Hi Simon,
> >
> > On Mon, Nov 25, 2019 at 12:12 PM Simon Glass <sjg at chromium.org> wrote:
> > >
> > > Apollo Lake (APL) only supports hardware sequencing. Add support for this
> > > into the SPI driver, as an option.
> > >
> > > Signed-off-by: Simon Glass <sjg at chromium.org>
> > >
> > > ---
> > >
> > > Changes in v5: None
> > > Changes in v4:
> > > - Fix comment for exec_sync_hwseq_xfer()
> > > - apollolake -> Apollo Lake
> > >
> > > Changes in v3: None
> > > Changes in v2: None
> > >
> > >  drivers/spi/ich.c | 205 +++++++++++++++++++++++++++++++++++++++++++++-
> > >  drivers/spi/ich.h |  39 +++++++++
> > >  2 files changed, 241 insertions(+), 3 deletions(-)
> > >
> >
> > [snip]
> >
> > > +static int ich_spi_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
> > > +{
> > > +       struct udevice *bus = dev_get_parent(slave->dev);
> > > +       struct ich_spi_platdata *plat = dev_get_platdata(bus);
> > > +       int ret;
> > > +
> > > +       bootstage_start(BOOTSTAGE_ID_ACCUM_SPI, "fast_spi");
> > > +       if (plat->hwseq)
> > > +               ret = ich_spi_exec_op_hwseq(slave, op);
> > > +       else
> > > +               ret = ich_spi_exec_op_swseq(slave, op);
> > > +       bootstage_accum(BOOTSTAGE_ID_ACCUM_SPI);
> > > +
> > > +       return ret;
> > > +}
> > > +
> > >  static int ich_spi_adjust_size(struct spi_slave *slave, struct spi_mem_op *op)
> > >  {
> > >         unsigned int page_offset;
> > > @@ -583,9 +778,11 @@ static int ich_spi_child_pre_probe(struct udevice *dev)
> > >
> > >         /*
> > >          * Yes this controller can only write a small number of bytes at
> > > -        * once! The limit is typically 64 bytes.
> > > +        * once! The limit is typically 64 bytes. For hardware sequencing a
> > > +        * a loop is used to get around this.
> > >          */
> > > -       slave->max_write_size = priv->databytes;
> > > +       if (!plat->hwseq)
> > > +               slave->max_write_size = priv->databytes;
> > >         /*
> > >          * ICH 7 SPI controller only supports array read command
> > >          * and byte program command for SST flash
> > > @@ -611,10 +808,12 @@ static int ich_spi_ofdata_to_platdata(struct udevice *dev)
> > >         plat->ich_version = dev_get_driver_data(dev);
> > >         plat->lockdown = dev_read_bool(dev, "intel,spi-lock-down");
> > >         pch_get_spi_base(priv->pch, &plat->mmio_base);
> > > +       plat->hwseq = dev_read_u32_default(dev, "intel,hardware-seq", 0);
> >
> > I believe dev_read_bool() is enough for now, unless we have different
> > types of hardware sequencer to support?
>
> Yes I remember this...unfortunately dtoc does not generate a struct
> member for a bool if it is not present (since it has no way of knowing
> it *might* be there.
>

OK, could you please put a comment here?

> So to keep of-platdata happy I made this a 0/1 value.
>
> We probably need a better solution but I don't have one right now.
>

Regards,
Bin