Commit 50433f6e authored by Krishna Chaitanya Chundru's avatar Krishna Chaitanya Chundru Committed by Bjorn Helgaas
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PCI: qcom: Use frequency and level based OPP lookup 



PCIe link configurations such as 8GT/s x2 and 16GT/s x1 may operate at the
same frequency, but differ in other characteristics like RPMh votes.  But
the existing OPP selection which is solely based on frequency (the 'opp-hz'
DT property) cannot distinguish between such cases.

Hence, use the newly introduced dev_pm_opp_find_key_exact() API to match
both frequency and level (the 'opp-level' property) when selecting an OPP,
here level indicates PCIe data rate.

To support older device trees where opp-level is not defined, check if
opp-level is present or not using dev_pm_opp_find_level_exact(). If
not present fallback to frequency only match.

Signed-off-by: default avatarKrishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
[mani: zero initialize dev_pm_opp_key struct]
Signed-off-by: default avatarManivannan Sadhasivam <mani@kernel.org>
[bhelgaas: add 'opp-hz' and 'opp-level' in commit log]
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20251013-opp_pcie-v5-5-eb64db2b4bd3@oss.qualcomm.com
parent 3a866087

drivers/pci/controller/dwc/pcie-qcom.c

+15 −2
Original line number Diff line number Diff line
@@ -1565,6 +1565,7 @@ static void qcom_pcie_icc_opp_update(struct qcom_pcie *pcie) 
{

	u32 offset, status, width, speed;

	struct dw_pcie *pci = pcie->pci;

	struct dev_pm_opp_key key = {};

	unsigned long freq_kbps;

	struct dev_pm_opp *opp;

	int ret, freq_mbps;
@@ -1592,8 +1593,20 @@ static void qcom_pcie_icc_opp_update(struct qcom_pcie *pcie) 
			return;



		freq_kbps = freq_mbps * KILO;

		opp = dev_pm_opp_find_level_exact(pci->dev, speed);

		if (IS_ERR(opp)) {

			 /* opp-level is not defined use only frequency */

			opp = dev_pm_opp_find_freq_exact(pci->dev, freq_kbps * width,

							 true);

		} else {

			/* put opp-level OPP */

			dev_pm_opp_put(opp);



			key.freq = freq_kbps * width;

			key.level = speed;

			key.bw = 0;

			opp = dev_pm_opp_find_key_exact(pci->dev, &key, true);

		}

		if (!IS_ERR(opp)) {

			ret = dev_pm_opp_set_opp(pci->dev, opp);

			if (ret)