Re: [PATCH v5 4/5] PCI: qcom: Add interconnect support to 2.7.0/1.9.0 ops

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On Fri 11 Feb 08:12 PST 2022, Lorenzo Pieralisi wrote:

> On Fri, Feb 04, 2022 at 05:38:33PM +0300, Dmitry Baryshkov wrote:
> > On 03/02/2022 18:57, Bjorn Andersson wrote:
> > > On Sat 18 Dec 06:10 PST 2021, Dmitry Baryshkov wrote:
> > > 
> > > > Add optional interconnect support for the 2.7.0/1.9.0 hosts. Set the
> > > > bandwidth according to the values from the downstream driver.
> > > > 
> > > 
> > > What memory transactions will travel this path? I would expect there to
> > > be two different paths involved, given the rather low bw numbers I
> > > presume this is the config path?
> > 
> > I think so. Downstream votes on this path for most of the known SoCs. Two
> > spotted omissions are ipq8074 and qcs404.
> > 
> > > 
> > > Is there no vote for the data path?
> > 
> > CNSS devices can vote additionally on the MASTER_PCI to memory paths:
> > For sm845 (45 = MASTER_PCIE):
> >                 qcom,msm-bus,vectors-KBps =
> >                         <45 512 0 0>,
> >                         <45 512 600000 800000>; /* ~4.6Gbps (MCS12) */
> > 
> > On sm8150/sm8250 qca bindings do not contain a vote, but wil6210 does (100 =
> > MASTER_PCIE_1):
> >                 qcom,msm-bus,vectors-KBps =
> >                         <100 512 0 0>,
> >                         <100 512 600000 800000>; /* ~4.6Gbps (MCS12) */
> > 
> > For sm8450 there are two paths used by cnss:
> > 		<&pcie_noc MASTER_PCIE_0 &pcie_noc SLAVE_ANOC_PCIE_GEM_NOC>,
> > 		<&gem_noc MASTER_ANOC_PCIE_GEM_NOC &mc_virt SLAVE_EBI1>;
> > 
> > with multiple entries per each path.
> > 
> > So, I'm not sure about these values.
> 
> This discussion is gating the series, please let me know if you want me
> to cherry-pick the other patches or you will resend the series.
> 

Please pick the other patches and I'll work with Dmitry to conclude how
this is actually connected to the busses inside the SoC.

Thanks,
Bjorn

> Lorenzo
> 
> > > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> > > > ---
> > > >   drivers/pci/controller/dwc/pcie-qcom.c | 11 +++++++++++
> > > >   1 file changed, 11 insertions(+)
> > > > 
> > > > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> > > > index d8d400423a0a..55ac3caa6d7d 100644
> > > > --- a/drivers/pci/controller/dwc/pcie-qcom.c
> > > > +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> > > > @@ -12,6 +12,7 @@
> > > >   #include <linux/crc8.h>
> > > >   #include <linux/delay.h>
> > > >   #include <linux/gpio/consumer.h>
> > > > +#include <linux/interconnect.h>
> > > >   #include <linux/interrupt.h>
> > > >   #include <linux/io.h>
> > > >   #include <linux/iopoll.h>
> > > > @@ -167,6 +168,7 @@ struct qcom_pcie_resources_2_7_0 {
> > > >   	struct clk *pipe_clk_src;
> > > >   	struct clk *phy_pipe_clk;
> > > >   	struct clk *ref_clk_src;
> > > > +	struct icc_path *path;
> > > >   };
> > > >   union qcom_pcie_resources {
> > > > @@ -1121,6 +1123,10 @@ static int qcom_pcie_get_resources_2_7_0(struct qcom_pcie *pcie)
> > > >   	if (IS_ERR(res->pci_reset))
> > > >   		return PTR_ERR(res->pci_reset);
> > > > +	res->path = devm_of_icc_get(dev, "pci");
> > > 
> > > The paths are typically identified using a string of the form
> > > <source>-<destination>.
> > > 
> > > 
> > > I don't see the related update to the DT binding for the introduction of
> > > the interconnect.
> > > 
> > > Regards,
> > > Bjorn
> > > 
> > > > +	if (IS_ERR(res->path))
> > > > +		return PTR_ERR(res->path);
> > > > +
> > > >   	res->supplies[0].supply = "vdda";
> > > >   	res->supplies[1].supply = "vddpe-3v3";
> > > >   	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(res->supplies),
> > > > @@ -1183,6 +1189,9 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
> > > >   	if (pcie->cfg->pipe_clk_need_muxing)
> > > >   		clk_set_parent(res->pipe_clk_src, res->phy_pipe_clk);
> > > > +	if (res->path)
> > > > +		icc_set_bw(res->path, 500, 800);
> > > > +
> > > >   	ret = clk_bulk_prepare_enable(res->num_clks, res->clks);
> > > >   	if (ret < 0)
> > > >   		goto err_disable_regulators;
> > > > @@ -1241,6 +1250,8 @@ static void qcom_pcie_deinit_2_7_0(struct qcom_pcie *pcie)
> > > >   	struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
> > > >   	clk_bulk_disable_unprepare(res->num_clks, res->clks);
> > > > +	if (res->path)
> > > > +		icc_set_bw(res->path, 0, 0);
> > > >   	/* Set TCXO as clock source for pcie_pipe_clk_src */
> > > >   	if (pcie->cfg->pipe_clk_need_muxing)
> > > > -- 
> > > > 2.34.1
> > > > 
> > 
> > 
> > -- 
> > With best wishes
> > Dmitry



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