On Tue, Aug 6, 2024 at 11:03 PM Manivannan Sadhasivam
<manivannan.sadhasivam@xxxxxxxxxx> wrote:
>
> On Wed, Jul 31, 2024 at 06:28:19PM -0400, Jim Quinlan wrote:
> > The 7712 SOC adds a software init reset device for the PCIe HW.
> > If found in the DT node, use it.
> >
> > Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
> > ---
> > drivers/pci/controller/pcie-brcmstb.c | 19 +++++++++++++++++++
> > 1 file changed, 19 insertions(+)
> >
> > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> > index 4d68fe318178..948fd4d176bc 100644
> > --- a/drivers/pci/controller/pcie-brcmstb.c
> > +++ b/drivers/pci/controller/pcie-brcmstb.c
> > @@ -266,6 +266,7 @@ struct brcm_pcie {
> > struct reset_control *rescal;
> > struct reset_control *perst_reset;
> > struct reset_control *bridge_reset;
> > + struct reset_control *swinit_reset;
> > int num_memc;
> > u64 memc_size[PCIE_BRCM_MAX_MEMC];
> > u32 hw_rev;
> > @@ -1633,12 +1634,30 @@ static int brcm_pcie_probe(struct platform_device *pdev)
> > if (IS_ERR(pcie->bridge_reset))
> > return PTR_ERR(pcie->bridge_reset);
> >
> > + pcie->swinit_reset = devm_reset_control_get_optional_exclusive(&pdev->dev, "swinit");
> > + if (IS_ERR(pcie->swinit_reset))
> > + return PTR_ERR(pcie->swinit_reset);
> > +
> > ret = clk_prepare_enable(pcie->clk);
> > if (ret)
> > return dev_err_probe(&pdev->dev, ret, "could not enable clock\n");
> >
> > pcie->bridge_sw_init_set(pcie, 0);
> >
> > + if (pcie->swinit_reset) {
>
> You already have a callback called 'bridge_sw_init_set', so this 'swinit_reset'
> is different from 'bridge_sw_init'?
Yes. The swinit_reset is a soft reset of the entire core while
bridge_sw_init reset is only for the bridge to system memory.
If so, does it make sense to move this into
> the callback itself to have all reset sequence in one place?
The order and placement of the resets can sometimes be fragile and I
would prefer to leave them where they are.
Regards,
Jim Quinlan
Broadcom STB/CM
>
> - Mani
>
> > + ret = reset_control_assert(pcie->swinit_reset);
> > + if (dev_err_probe(&pdev->dev, ret, "could not assert reset 'swinit'\n"))
> > + goto clk_disable_unprepare;
> > +
> > + /* HW team recommends 1us for proper sync and propagation of reset */
> > + udelay(1);
> > +
> > + ret = reset_control_deassert(pcie->swinit_reset);
> > + if (dev_err_probe(&pdev->dev, ret,
> > + "could not de-assert reset 'swinit' after asserting\n"))
> > + goto clk_disable_unprepare;
> > + }
> > +
> > ret = reset_control_reset(pcie->rescal);
> > if (dev_err_probe(&pdev->dev, ret, "failed to deassert 'rescal'\n"))
> > goto clk_disable_unprepare;
> > --
> > 2.17.1
> >
>
> --
> மணிவண்ணன் சதாசிவம்
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