On Thu, Sep 07, 2023 at 11:30:33AM +0530, Krishna chaitanya chundru wrote:
> While scaling the interconnect clocks based on PCIe link speed, it is also
> mandatory to scale the power domain performance state so that the SoC can
> run under optimum power conditions.
>
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-qcom.c | 58 ++++++++++++++++++++++++++++------
> 1 file changed, 49 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index ca6350b..1817e96 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -22,6 +22,7 @@
> #include <linux/of.h>
> #include <linux/of_gpio.h>
> #include <linux/pci.h>
> +#include <linux/pm_opp.h>
> #include <linux/pm_runtime.h>
> #include <linux/platform_device.h>
> #include <linux/phy/pcie.h>
> @@ -240,6 +241,7 @@ struct qcom_pcie {
> const struct qcom_pcie_cfg *cfg;
> struct dentry *debugfs;
> bool suspended;
> + bool opp_supported;
> };
>
> #define to_qcom_pcie(x) dev_get_drvdata((x)->dev)
> @@ -1357,14 +1359,13 @@ static int qcom_pcie_icc_init(struct qcom_pcie *pcie)
> return 0;
> }
>
> -static int qcom_pcie_icc_update(struct qcom_pcie *pcie)
> +static int qcom_pcie_icc_opp_update(struct qcom_pcie *pcie)
> {
> struct dw_pcie *pci = pcie->pci;
> + struct dev_pm_opp *opp;
> u32 offset, status, bw;
> int speed, width;
> -
> - if (!pcie->icc_mem)
> - return 0;
> + int ret;
>
> offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
> @@ -1391,7 +1392,21 @@ static int qcom_pcie_icc_update(struct qcom_pcie *pcie)
> break;
> }
>
> - return icc_set_bw(pcie->icc_mem, 0, width * bw);
> + if (pcie->opp_supported) {
> + opp = dev_pm_opp_find_level_exact(pci->dev, speed);
> + if (!IS_ERR(opp)) {
> + ret = dev_pm_opp_set_opp(pci->dev, opp);
> + if (ret)
> + dev_err(pci->dev, "Failed to set opp: level %d ret %d\n",
> + dev_pm_opp_get_level(opp), ret);
> + dev_pm_opp_put(opp);
> + }
> + }
> +
> + if (pcie->icc_mem)
> + ret = icc_set_bw(pcie->icc_mem, 0, width * bw);
I think you should tie interconnect scaling with OPP as suggested by Viresh,
since you are updating both OPP and BW at the same time.
- Mani
> +
> + return ret;
> }
>
> static int qcom_pcie_link_transition_count(struct seq_file *s, void *data)
> @@ -1434,8 +1449,10 @@ static void qcom_pcie_init_debugfs(struct qcom_pcie *pcie)
> static int qcom_pcie_probe(struct platform_device *pdev)
> {
> const struct qcom_pcie_cfg *pcie_cfg;
> + unsigned long max_level = INT_MAX;
> struct device *dev = &pdev->dev;
> struct qcom_pcie *pcie;
> + struct dev_pm_opp *opp;
> struct dw_pcie_rp *pp;
> struct resource *res;
> struct dw_pcie *pci;
> @@ -1506,6 +1523,27 @@ static int qcom_pcie_probe(struct platform_device *pdev)
> if (ret)
> goto err_pm_runtime_put;
>
> + /* OPP table is optional */
> + ret = devm_pm_opp_of_add_table(dev);
> + if (ret && ret != -ENODEV) {
> + dev_err_probe(dev, ret, "Failed to add OPP table\n");
> + goto err_pm_runtime_put;
> + }
> +
> + /* vote for max level in the opp table if opp table is present */
> + if (ret != -ENODEV) {
> + opp = dev_pm_opp_find_level_floor(dev, &max_level);
> + if (!IS_ERR(opp)) {
> + ret = dev_pm_opp_set_opp(dev, opp);
> + if (ret)
> + dev_err_probe(pci->dev, ret,
> + "Failed to set opp: level %d\n",
> + dev_pm_opp_get_level(opp));
> + dev_pm_opp_put(opp);
> + }
> + pcie->opp_supported = true;
> + }
> +
> ret = pcie->cfg->ops->get_resources(pcie);
> if (ret)
> goto err_pm_runtime_put;
> @@ -1524,9 +1562,9 @@ static int qcom_pcie_probe(struct platform_device *pdev)
> goto err_phy_exit;
> }
>
> - ret = qcom_pcie_icc_update(pcie);
> + ret = qcom_pcie_icc_opp_update(pcie);
> if (ret)
> - dev_err(dev, "failed to update interconnect bandwidth: %d\n",
> + dev_err(dev, "failed to update interconnect bandwidth/opp: %d\n",
> ret);
>
> if (pcie->mhi)
> @@ -1575,6 +1613,8 @@ static int qcom_pcie_suspend_noirq(struct device *dev)
> */
> if (!dw_pcie_link_up(pcie->pci)) {
> qcom_pcie_host_deinit(&pcie->pci->pp);
> + if (pcie->opp_supported)
> + dev_pm_opp_set_opp(dev, NULL);
> pcie->suspended = true;
> }
>
> @@ -1594,9 +1634,9 @@ static int qcom_pcie_resume_noirq(struct device *dev)
> pcie->suspended = false;
> }
>
> - ret = qcom_pcie_icc_update(pcie);
> + ret = qcom_pcie_icc_opp_update(pcie);
> if (ret)
> - dev_err(dev, "failed to update interconnect bandwidth: %d\n",
> + dev_err(dev, "failed to update interconnect bandwidth/opp: %d\n",
> ret);
>
> return 0;
> --
> 2.7.4
>
--
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