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://patchwork.kernel.org/project/linux-pci/patch/20221102090705.23634-3-johan+linaro@xxxxxxxxxx/ 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..5f9139d 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; + 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; + int speed, width; + u32 val, bw; + int ret; + + if (!pcie_ep->icc) + return; + + val = dw_pcie_readl_dbi(pci, DBI_LINKCTRLSTATUS); + val = val >> DBI_LINKCTRLSTATUS_SHIFT; + + speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, val); + width = FIELD_GET(PCI_EXP_LNKSTA_NLW, val); + + switch (speed) { + case 1: + bw = MBps_to_icc(250); /* BW for GEN1 per lane: 250MBps */ + 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: 985MBps */ + break; + } + + ret = icc_set_bw(pcie_ep->icc, 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 single-lane Gen 1 + * for the pcie to mem path. + */ + ret = icc_set_bw(pcie_ep->icc, 0, MBps_to_icc(250)); /* BW for GEN1 per lane: 250MBps */ + 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 = devm_of_icc_get(dev, "pcie-mem"); + if (IS_ERR(pcie_ep->icc)) + ret = PTR_ERR(pcie_ep->icc); + 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
