On Mon, 2015-10-12 at 15:41 +0800, Xiang Wang wrote:
> Hi, Andy
> Thanks for your comments.
>
> [Andy] Don't see a relationship between PCI driver and this ACPI
> stuff.
> Although this is a pci driver, we may enumerate the i2c devices from
> DSDT table while i2c controllers are enumerated via PCI. In this
> scenario, in DSDT, there are descriptions of i2c devices as well as
> i2c controllers. The ACPI node of i2c controllers are bond to i2c PCI
> devices via pci-acpi glue.
> So if we want to determine the i2c devices' settings (e.g. bus
> speed),
> we should leverage ACPI.
>
> Above is also the reason why the ACPI stuff is put in
> i2c-designware-core: i2c_dw_acpi_setup_speed can be used by both plat
> and pci driver. Thanks
Wait, first of all let's divide parameters to two groups: a) to be
applied to host driver, and b) to be applied to slave devices.
The drivers/i2c/busses/i2c-designware* is about host driver parameters.
Thus, PCI driver comes with hardcoded values since it's enumerated via
PCI, and platform driver utilizes ACPI values.
For slave devices everything is done in i2c-core.c.
So, what exactly you are trying to enhance?
>
> 2015-10-09 17:31 GMT+08:00 Andy Shevchenko <
> andriy.shevchenko@xxxxxxxxxxxxxxx>:
> > On Fri, 2015-10-09 at 16:47 +0800, wangxfdu@xxxxxxxxx wrote:
> > > From: Xiang Wang <xiang.a.wang@xxxxxxxxx>
> > >
> > > 1. Support setting hs_hcnt and hs_lcnt
> > > 2. Get bus speed mode from ACPI companion of the
> > > i2c controller.
> > >
> > > Signed-off-by: Xiang Wang <xiang.a.wang@xxxxxxxxx>
> > > ---
> > > drivers/i2c/busses/i2c-designware-pcidrv.c | 7 +++++++
> > > 1 file changed, 7 insertions(+)
> > >
> > > diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c
> > > b/drivers/i2c/busses/i2c-designware-pcidrv.c
> > > index 6643d2d..0f4c0c4 100644
> > > --- a/drivers/i2c/busses/i2c-designware-pcidrv.c
> > > +++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
> > > @@ -54,8 +54,10 @@ enum dw_pci_ctl_id_t {
> > > struct dw_scl_sda_cfg {
> > > u32 ss_hcnt;
> > > u32 fs_hcnt;
> > > + u32 hs_hcnt;
> > > u32 ss_lcnt;
> > > u32 fs_lcnt;
> > > + u32 hs_lcnt;
> > > u32 sda_hold;
> > > };
> > >
> > > @@ -237,8 +239,10 @@ static int i2c_dw_pci_probe(struct pci_dev
> > > *pdev,
> > > cfg = controller->scl_sda_cfg;
> > > dev->ss_hcnt = cfg->ss_hcnt;
> > > dev->fs_hcnt = cfg->fs_hcnt;
> > > + dev->hs_hcnt = cfg->hs_hcnt;
> > > dev->ss_lcnt = cfg->ss_lcnt;
> > > dev->fs_lcnt = cfg->fs_lcnt;
> > > + dev->hs_lcnt = cfg->hs_lcnt;
> > > dev->sda_hold_time = cfg->sda_hold;
> > > }
> > >
> > > @@ -246,6 +250,9 @@ static int i2c_dw_pci_probe(struct pci_dev
> > > *pdev,
> > >
> > > dev->tx_fifo_depth = controller->tx_fifo_depth;
> > > dev->rx_fifo_depth = controller->rx_fifo_depth;
> > > +
> > > + i2c_dw_acpi_setup_speed(&pdev->dev, dev);
> >
> > Don't see a relationship between PCI driver and this ACPI stuff.
> >
> > > +
> > > r = i2c_dw_init(dev);
> > > if (r)
> > > return r;
> >
> > --
> > Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > Intel Finland Oy
>
>
>
--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
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