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

[Dmitry Baryshkov]

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.

> 
>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
>> ---
>>   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