Re: [PATCH V5 6/6] PCI: qcom: Add support for IPQ9574

[Devi Priya <quic_devipriy@xxxxxxxxxxx>]

On 5/30/2024 8:17 PM, Manivannan Sadhasivam wrote:
> On Sun, May 12, 2024 at 01:58:58PM +0530, devi priya wrote:
> > The IPQ9574 platform has 4 Gen3 PCIe controllers:
> > two single-lane and two dual-lane based on SNPS core 5.70a
> >
> > The Qcom IP rev is 1.27.0 and Synopsys IP rev is 5.80a
> > Added a new compatible 'qcom,pcie-ipq9574' and 'ops_1_27_0'
> > which reuses all the members of 'ops_2_9_0' except for the post_init
> > as the SLV_ADDR_SPACE_SIZE configuration differs between 2_9_0
> > and 1_27_0.
> >
> > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> > Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> > Co-developed-by: Anusha Rao <quic_anusha@xxxxxxxxxxx>
> > Signed-off-by: Anusha Rao <quic_anusha@xxxxxxxxxxx>
> > Signed-off-by: devi priya <quic_devipriy@xxxxxxxxxxx>
> > ---
> >   Changes in V5:
> > 	- Rebased on top of the below series which adds support for fetching
> > 	  clocks from the device tree
> > 	  https://lore.kernel.org/linux-pci/20240417-pci-qcom-clk-bulk-v1-1-52ca19b3d6b2@xxxxxxxxxx/
> >
> >   drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++---
> >   1 file changed, 32 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> > index 3d2eeff9a876..af36a29c092e 100644
> > --- a/drivers/pci/controller/dwc/pcie-qcom.c
> > +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> > @@ -106,6 +106,7 @@
> >   
> >   /* PARF_SLV_ADDR_SPACE_SIZE register value */
> >   #define SLV_ADDR_SPACE_SZ			0x10000000
> > +#define SLV_ADDR_SPACE_SZ_1_27_0		0x08000000
>
> Can you please explain what this value corresponds to? Even though there is an
> old value, I didn't get much info earlier on what it is.

The PARF_SLV_ADDR_SPACE_SIZE register indicates the range of RC accesses
to the EP's memory space. Default PoR value is 16MB, which seems to be 
sufficient for IPQ9574 SoC.
As per the memory map, the memory space corresponding to each PCIe 
region is 128Mb. As the older value corresponds to 256Mb we see PCIe 
enumeration failures.
This register should either be updated to 128Mb(0x8000000) or left at 
the PoR value 16Mb (0x1000000).

Thanks,
Devi Priya
> - Mani
>
> >   
> >   /* PARF_MHI_CLOCK_RESET_CTRL register fields */
> >   #define AHB_CLK_EN				BIT(0)
> > @@ -1095,16 +1096,13 @@ static int qcom_pcie_init_2_9_0(struct qcom_pcie *pcie)
> >   	return clk_bulk_prepare_enable(res->num_clks, res->clks);
> >   }
> >   
> > -static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
> > +static int qcom_pcie_post_init(struct qcom_pcie *pcie)
> >   {
> >   	struct dw_pcie *pci = pcie->pci;
> >   	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> >   	u32 val;
> >   	int i;
> >   
> > -	writel(SLV_ADDR_SPACE_SZ,
> > -		pcie->parf + PARF_SLV_ADDR_SPACE_SIZE);
> > -
> >   	val = readl(pcie->parf + PARF_PHY_CTRL);
> >   	val &= ~PHY_TEST_PWR_DOWN;
> >   	writel(val, pcie->parf + PARF_PHY_CTRL);
> > @@ -1144,6 +1142,22 @@ static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
> >   	return 0;
> >   }
> >   
> > +static int qcom_pcie_post_init_1_27_0(struct qcom_pcie *pcie)
> > +{
> > +	writel(SLV_ADDR_SPACE_SZ_1_27_0,
> > +	       pcie->parf + PARF_SLV_ADDR_SPACE_SIZE);
> > +
> > +	return qcom_pcie_post_init(pcie);
> > +}
> > +
> > +static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
> > +{
> > +	writel(SLV_ADDR_SPACE_SZ,
> > +	       pcie->parf + PARF_SLV_ADDR_SPACE_SIZE);
> > +
> > +	return qcom_pcie_post_init(pcie);
> > +}
> > +
> >   static int qcom_pcie_link_up(struct dw_pcie *pci)
> >   {
> >   	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> > @@ -1297,6 +1311,15 @@ static const struct qcom_pcie_ops ops_2_9_0 = {
> >   	.ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
> >   };
> >   
> > +/* Qcom IP rev.: 1.27.0  Synopsys IP rev.: 5.80a */
> > +static const struct qcom_pcie_ops ops_1_27_0 = {
> > +	.get_resources = qcom_pcie_get_resources_2_9_0,
> > +	.init = qcom_pcie_init_2_9_0,
> > +	.post_init = qcom_pcie_post_init_1_27_0,
> > +	.deinit = qcom_pcie_deinit_2_9_0,
> > +	.ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
> > +};
> > +
> >   static const struct qcom_pcie_cfg cfg_1_0_0 = {
> >   	.ops = &ops_1_0_0,
> >   };
> > @@ -1334,6 +1357,10 @@ static const struct qcom_pcie_cfg cfg_sc8280xp = {
> >   	.no_l0s = true,
> >   };
> >   
> > +static const struct qcom_pcie_cfg cfg_1_27_0 = {
> > +	.ops = &ops_1_27_0,
> > +};
> > +
> >   static const struct dw_pcie_ops dw_pcie_ops = {
> >   	.link_up = qcom_pcie_link_up,
> >   	.start_link = qcom_pcie_start_link,
> > @@ -1603,6 +1630,7 @@ static const struct of_device_id qcom_pcie_match[] = {
> >   	{ .compatible = "qcom,pcie-ipq8064-v2", .data = &cfg_2_1_0 },
> >   	{ .compatible = "qcom,pcie-ipq8074", .data = &cfg_2_3_3 },
> >   	{ .compatible = "qcom,pcie-ipq8074-gen3", .data = &cfg_2_9_0 },
> > +	{ .compatible = "qcom,pcie-ipq9574", .data = &cfg_1_27_0 },
> >   	{ .compatible = "qcom,pcie-msm8996", .data = &cfg_2_3_2 },
> >   	{ .compatible = "qcom,pcie-qcs404", .data = &cfg_2_4_0 },
> >   	{ .compatible = "qcom,pcie-sa8540p", .data = &cfg_sc8280xp },
> > --
> > 2.34.1