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From:   Krishna chaitanya chundru <quic_krichai@quicinc.com>
To:     helgaas@kernel.org
Cc:     linux-pci@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, quic_vbadigan@quicinc.com,
        quic_hemantk@quicinc.com, quic_ramkri@quicinc.com,
        manivannan.sadhasivam@linaro.org, swboyd@chromium.org,
        Krishna chaitanya chundru <quic_krichai@quicinc.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Stanimir Varbanov <svarbanov@mm-sol.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>
Subject: [PATCH v1] PCI: qcom: Allow L1 and its sub states on qcom dwc wrapper
Date:   Fri,  3 Jun 2022 12:48:50 +0530
Message-Id: <1654240730-31322-1-git-send-email-quic_krichai@quicinc.com>
Precedence: bulk

Allow L1 and its sub-states in the qcom dwc pcie wrapper.
By default its disabled. So enable it explicitly.

Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 6ab9089..f60645c 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -41,6 +41,9 @@
 #define L23_CLK_RMV_DIS				BIT(2)
 #define L1_CLK_RMV_DIS				BIT(1)
 
+#define PCIE20_PARF_PM_CTRL			0x20
+#define REQ_NOT_ENTR_L1				BIT(5)
+
 #define PCIE20_PARF_PHY_CTRL			0x40
 #define PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK	GENMASK(20, 16)
 #define PHY_CTRL_PHY_TX0_TERM_OFFSET(x)		((x) << 16)
@@ -1267,6 +1270,11 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
 	val |= BIT(4);
 	writel(val, pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
 
+	/* Clear PARF PM REQ_NOT_ENTR_L1 bit to allow L1 states */
+	val = readl(pcie->parf + PCIE20_PARF_PM_CTRL);
+	val &= ~REQ_NOT_ENTR_L1;
+	writel(val, pcie->parf + PCIE20_PARF_PM_CTRL);
+
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		val = readl(pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
 		val |= BIT(31);
-- 
2.7.4