On Fri, 9 Jun 2023 at 14:47, Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx> wrote: > > Add support to vote for ICC bandwidth based on the link speed and width. > > This patch is inspired from pcie-qcom driver to add basic interconnect > support. > > Link: https://lore.kernel.org/all/20221102090705.23634-1-johan+linaro@xxxxxxxxxx/ This link should be a part of the cover letter, not the commit msg. If you want to refer to the previous commits, please use the standard reference: commit abcdefabc ("PCI: qcom: Make foo and bar"). > Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx> > --- > drivers/pci/controller/dwc/pcie-qcom-ep.c | 68 +++++++++++++++++++++++++++++++ > 1 file changed, 68 insertions(+) > > diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c > index 19b3283..baf831f 100644 > --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c > +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c > @@ -13,6 +13,7 @@ > #include <linux/debugfs.h> > #include <linux/delay.h> > #include <linux/gpio/consumer.h> > +#include <linux/interconnect.h> > #include <linux/mfd/syscon.h> > #include <linux/phy/pcie.h> > #include <linux/phy/phy.h> > @@ -28,6 +29,7 @@ > #define PARF_SYS_CTRL 0x00 > #define PARF_DB_CTRL 0x10 > #define PARF_PM_CTRL 0x20 > +#define PARF_PM_STTS 0x24 > #define PARF_MHI_CLOCK_RESET_CTRL 0x174 > #define PARF_MHI_BASE_ADDR_LOWER 0x178 > #define PARF_MHI_BASE_ADDR_UPPER 0x17c > @@ -128,6 +130,9 @@ > /* DBI register fields */ > #define DBI_CON_STATUS_POWER_STATE_MASK GENMASK(1, 0) > > +#define DBI_LINKCTRLSTATUS 0x80 > +#define DBI_LINKCTRLSTATUS_SHIFT 16 > + > #define XMLH_LINK_UP 0x400 > #define CORE_RESET_TIME_US_MIN 1000 > #define CORE_RESET_TIME_US_MAX 1005 > @@ -178,6 +183,8 @@ struct qcom_pcie_ep { > struct phy *phy; > struct dentry *debugfs; > > + struct icc_path *icc_mem; > + > struct clk_bulk_data *clks; > int num_clks; > > @@ -253,9 +260,51 @@ static void qcom_pcie_dw_stop_link(struct dw_pcie *pci) > disable_irq(pcie_ep->perst_irq); > } > > +static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep) > +{ > + struct dw_pcie *pci = &pcie_ep->pci; > + u32 offset, status, bw; > + int speed, width; > + int ret; > + > + if (!pcie_ep->icc_mem) > + return; > + > + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > + status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA); > + > + speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status); > + width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status); > + > + switch (speed) { > + case 1: > + bw = MBps_to_icc(250); /* BW for GEN1 per lane: 250MBps */ Please extract these constants to the defines. This would save you from duplicating 250 below. > + break; > + case 2: > + bw = MBps_to_icc(500); /* BW for GEN2 per lane: 500MBps */ > + break; > + case 3: > + bw = MBps_to_icc(985); /* BW for GEN3 per lane: 985MBps */ > + break; > + default: > + WARN_ON_ONCE(1); > + fallthrough; > + case 4: > + bw = MBps_to_icc(1969); /* BW for GEN4 per lane:1969MBps */ > + break; > + } > + > + ret = icc_set_bw(pcie_ep->icc_mem, 0, width * bw); > + if (ret) { > + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n", > + ret); > + } > +} > + > static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep) > { > int ret; > + struct dw_pcie *pci = &pcie_ep->pci; > > ret = clk_bulk_prepare_enable(pcie_ep->num_clks, pcie_ep->clks); > if (ret) > @@ -277,6 +326,20 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep) > if (ret) > goto err_phy_exit; > > + /* > + * Some Qualcomm platforms require interconnect bandwidth constraints > + * to be set before enabling interconnect clocks. > + * > + * Set an initial average bandwidth corresponding to GEN1x1(250 MBps) > + * for the pcie to mem path. > + */ > + ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(250)); > + if (ret) { > + dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n", > + ret); > + goto err_phy_exit; > + } > + > return 0; > > err_phy_exit: > @@ -550,6 +613,10 @@ static int qcom_pcie_ep_get_resources(struct platform_device *pdev, > if (IS_ERR(pcie_ep->phy)) > ret = PTR_ERR(pcie_ep->phy); > > + pcie_ep->icc_mem = devm_of_icc_get(dev, "pcie-mem"); > + if (IS_ERR(pcie_ep->icc_mem)) > + ret = PTR_ERR(pcie_ep->icc_mem); > + > return ret; > } > > @@ -572,6 +639,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data) > } else if (FIELD_GET(PARF_INT_ALL_BME, status)) { > dev_dbg(dev, "Received BME event. Link is enabled!\n"); > pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED; > + qcom_pcie_ep_icc_update(pcie_ep); > } else if (FIELD_GET(PARF_INT_ALL_PM_TURNOFF, status)) { > dev_dbg(dev, "Received PM Turn-off event! Entering L23\n"); > val = readl_relaxed(pcie_ep->parf + PARF_PM_CTRL); > -- > 2.7.4 > -- With best wishes Dmitry
