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From: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
To: <agross@kernel.org>, <andersson@kernel.org>, <konrad.dybcio@linaro.org>,
        <mani@kernel.org>
CC: <quic_msarkar@quicinc.com>, <quic_kraravin@quicinc.com>,
        Lorenzo Pieralisi
	<lpieralisi@kernel.org>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?=
	<kw@linux.com>,
        Rob Herring <robh@kernel.org>, Bjorn Helgaas
	<bhelgaas@google.com>,
        Manivannan Sadhasivam
	<manivannan.sadhasivam@linaro.org>,
        Serge Semin <fancer.lancer@gmail.com>,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
        Conor Dooley
	<conor.dooley@microchip.com>,
        Josh Triplett <josh@joshtriplett.org>, <linux-kernel@vger.kernel.org>,
        <linux-pci@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>
Subject: [PATCH v1 1/3] PCI: dwc: refactor common code
Date: Thu, 29 Feb 2024 21:11:34 -0800
Message-ID: <20240301051220.20917-2-quic_schintav@quicinc.com>
In-Reply-To: <20240301051220.20917-1-quic_schintav@quicinc.com>
References: <20240301051220.20917-1-quic_schintav@quicinc.com>
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Refactor common code from RC(Root Complex) and EP(End Point)
drivers and move them to a common repository. This acts as placeholder
for common source code for both drivers avoiding duplication.

Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
---
 drivers/pci/controller/dwc/Kconfig         |  5 ++
 drivers/pci/controller/dwc/Makefile        |  1 +
 drivers/pci/controller/dwc/pcie-qcom-cmn.c | 85 ++++++++++++++++++++++
 drivers/pci/controller/dwc/pcie-qcom-cmn.h | 30 ++++++++
 drivers/pci/controller/dwc/pcie-qcom-ep.c  | 39 +---------
 drivers/pci/controller/dwc/pcie-qcom.c     | 67 ++---------------
 6 files changed, 133 insertions(+), 94 deletions(-)
 create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.c
 create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.h

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 8afacc90c63b..41d2746edc5f 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -265,12 +265,16 @@ config PCIE_DW_PLAT_EP
 	  order to enable device-specific features PCI_DW_PLAT_EP must be
 	  selected.
 
+config PCIE_QCOM_CMN
+	bool
+
 config PCIE_QCOM
 	bool "Qualcomm PCIe controller (host mode)"
 	depends on OF && (ARCH_QCOM || COMPILE_TEST)
 	depends on PCI_MSI
 	select PCIE_DW_HOST
 	select CRC8
+	select PCIE_QCOM_CMN
 	help
 	  Say Y here to enable PCIe controller support on Qualcomm SoCs. The
 	  PCIe controller uses the DesignWare core plus Qualcomm-specific
@@ -281,6 +285,7 @@ config PCIE_QCOM_EP
 	depends on OF && (ARCH_QCOM || COMPILE_TEST)
 	depends on PCI_ENDPOINT
 	select PCIE_DW_EP
+	select PCIE_QCOM_CMN
 	help
 	  Say Y here to enable support for the PCIe controllers on Qualcomm SoCs
 	  to work in endpoint mode. The PCIe controller uses the DesignWare core
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index bac103faa523..022dc73c38a5 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
 obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
 obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o
 obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4.o
+obj-$(CONFIG_PCIE_QCOM_CMN) += pcie-qcom-cmn.o
 
 # The following drivers are for devices that use the generic ACPI
 # pci_root.c driver but don't support standard ECAM config access.
diff --git a/drivers/pci/controller/dwc/pcie-qcom-cmn.c b/drivers/pci/controller/dwc/pcie-qcom-cmn.c
new file mode 100644
index 000000000000..0f8d004fbc79
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014-2015, 2020 The Linux Foundation. All rights reserved.
+ * Copyright 2015, 2021 Linaro Limited.
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ *
+ */
+
+#include <linux/debugfs.h>
+#include <linux/pci.h>
+#include <linux/interconnect.h>
+
+#include "../../pci.h"
+#include "pcie-designware.h"
+#include "pcie-qcom-cmn.h"
+
+
+#define QCOM_PCIE_LINK_SPEED_TO_BW(speed) \
+		Mbps_to_icc(PCIE_SPEED2MBS_ENC(pcie_link_speed[speed]))
+
+
+int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)
+{
+	int ret = 0;
+
+	if (IS_ERR(pci))
+		return PTR_ERR(pci);
+
+	icc_mem = devm_of_icc_get(pci->dev, "pcie-mem");
+	if (IS_ERR(icc_mem))
+		return PTR_ERR(icc_mem);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(qcom_pcie_cmn_icc_get_resource);
+
+int qcom_pcie_cmn_icc_init(struct dw_pcie *pci, struct icc_path *icc_mem)
+{
+	int ret = 0;
+
+	if (IS_ERR(pci))
+		return PTR_ERR(pci);
+
+	if (IS_ERR(icc_mem))
+		return PTR_ERR(icc_mem);
+
+	/*
+	 * Some Qualcomm platforms require interconnect bandwidth constraints
+	 * to be set before enabling interconnect clocks.
+	 *
+	 * Set an initial peak bandwidth corresponding to single-lane Gen 1
+	 * for the pcie-mem path.
+	 */
+	ret = icc_set_bw(icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1));
+	if (ret) {
+		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_pcie_cmn_icc_init);
+
+void qcom_pcie_cmn_icc_update(struct dw_pcie *pci, struct icc_path *icc_mem)
+{
+	u32 offset, status;
+	int speed, width;
+	int ret;
+
+	if (!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);
+
+	ret = icc_set_bw(icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed));
+	if (ret)
+		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+			ret);
+}
+EXPORT_SYMBOL_GPL(qcom_pcie_cmn_icc_update);
diff --git a/drivers/pci/controller/dwc/pcie-qcom-cmn.h b/drivers/pci/controller/dwc/pcie-qcom-cmn.h
new file mode 100644
index 000000000000..8794dbd4775c
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2014-2015, 2020 The Linux Foundation. All rights reserved.
+ * Copyright 2015, 2021 Linaro Limited.
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/pci.h>
+#include "../../pci.h"
+#include "pcie-designware.h"
+
+#ifdef CONFIG_PCIE_QCOM_CMN
+int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem);
+int qcom_pcie_cmn_icc_init(struct dw_pcie *pci, struct icc_path *icc_mem);
+void qcom_pcie_cmn_icc_update(struct dw_pcie *pci, struct icc_path *icc_mem);
+#else
+static inline int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)
+{
+	return 0;
+}
+
+static inline int qcom_pcie_cmn_icc_init(struct dw_pcie *pci, struct icc_path *icc_mem)
+{
+	return 0;
+}
+
+static inline void qcom_pcie_cmn_icc_update(struct dw_pcie *pci, struct icc_path *icc_mem)
+{
+}
+#endif
diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 36e5e80cd22f..ce6343426de8 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -25,6 +25,7 @@
 
 #include "../../pci.h"
 #include "pcie-designware.h"
+#include "pcie-qcom-cmn.h"
 
 /* PARF registers */
 #define PARF_SYS_CTRL				0x00
@@ -137,9 +138,6 @@
 #define CORE_RESET_TIME_US_MAX			1005
 #define WAKE_DELAY_US				2000 /* 2 ms */
 
-#define QCOM_PCIE_LINK_SPEED_TO_BW(speed) \
-		Mbps_to_icc(PCIE_SPEED2MBS_ENC(pcie_link_speed[speed]))
-
 #define to_pcie_ep(x)				dev_get_drvdata((x)->dev)
 
 enum qcom_pcie_ep_link_status {
@@ -278,28 +276,6 @@ static void qcom_pcie_dw_write_dbi2(struct dw_pcie *pci, void __iomem *base,
 	writel(0, pcie_ep->elbi + ELBI_CS2_ENABLE);
 }
 
-static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep)
-{
-	struct dw_pcie *pci = &pcie_ep->pci;
-	u32 offset, status;
-	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);
-
-	ret = icc_set_bw(pcie_ep->icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed));
-	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)
 {
 	struct dw_pcie *pci = &pcie_ep->pci;
@@ -325,14 +301,7 @@ 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 peak bandwidth corresponding to single-lane Gen 1
-	 * for the pcie-mem path.
-	 */
-	ret = icc_set_bw(pcie_ep->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1));
+	ret = qcom_pcie_cmn_icc_init(pci, pcie_ep->icc_mem);
 	if (ret) {
 		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
 			ret);
@@ -616,7 +585,7 @@ 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");
+	ret = qcom_pcie_cmn_icc_get_resource(&pcie_ep->pci, pcie_ep->icc_mem);
 	if (IS_ERR(pcie_ep->icc_mem))
 		ret = PTR_ERR(pcie_ep->icc_mem);
 
@@ -643,7 +612,7 @@ 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);
+		qcom_pcie_cmn_icc_update(pci, pcie_ep->icc_mem);
 		pci_epc_bme_notify(pci->ep.epc);
 	} else if (FIELD_GET(PARF_INT_ALL_PM_TURNOFF, status)) {
 		dev_dbg(dev, "Received PM Turn-off event! Entering L23\n");
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 2ce2a3bd932b..57a08294c561 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -32,6 +32,7 @@
 #include <linux/types.h>
 
 #include "../../pci.h"
+#include "pcie-qcom-cmn.h"
 #include "pcie-designware.h"
 
 /* PARF registers */
@@ -147,9 +148,6 @@
 
 #define QCOM_PCIE_CRC8_POLYNOMIAL		(BIT(2) | BIT(1) | BIT(0))
 
-#define QCOM_PCIE_LINK_SPEED_TO_BW(speed) \
-		Mbps_to_icc(PCIE_SPEED2MBS_ENC(pcie_link_speed[speed]))
-
 #define QCOM_PCIE_1_0_0_MAX_CLOCKS		4
 struct qcom_pcie_resources_1_0_0 {
 	struct clk_bulk_data clks[QCOM_PCIE_1_0_0_MAX_CLOCKS];
@@ -1363,59 +1361,6 @@ static const struct dw_pcie_ops dw_pcie_ops = {
 	.start_link = qcom_pcie_start_link,
 };
 
-static int qcom_pcie_icc_init(struct qcom_pcie *pcie)
-{
-	struct dw_pcie *pci = pcie->pci;
-	int ret;
-
-	pcie->icc_mem = devm_of_icc_get(pci->dev, "pcie-mem");
-	if (IS_ERR(pcie->icc_mem))
-		return PTR_ERR(pcie->icc_mem);
-
-	/*
-	 * Some Qualcomm platforms require interconnect bandwidth constraints
-	 * to be set before enabling interconnect clocks.
-	 *
-	 * Set an initial peak bandwidth corresponding to single-lane Gen 1
-	 * for the pcie-mem path.
-	 */
-	ret = icc_set_bw(pcie->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1));
-	if (ret) {
-		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
-			ret);
-		return ret;
-	}
-
-	return 0;
-}
-
-static void qcom_pcie_icc_update(struct qcom_pcie *pcie)
-{
-	struct dw_pcie *pci = pcie->pci;
-	u32 offset, status;
-	int speed, width;
-	int ret;
-
-	if (!pcie->icc_mem)
-		return;
-
-	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
-	status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
-
-	/* Only update constraints if link is up. */
-	if (!(status & PCI_EXP_LNKSTA_DLLLA))
-		return;
-
-	speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
-	width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
-
-	ret = icc_set_bw(pcie->icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed));
-	if (ret) {
-		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
-			ret);
-	}
-}
-
 static int qcom_pcie_link_transition_count(struct seq_file *s, void *data)
 {
 	struct qcom_pcie *pcie = (struct qcom_pcie *)dev_get_drvdata(s->private);
@@ -1524,7 +1469,11 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 		goto err_pm_runtime_put;
 	}
 
-	ret = qcom_pcie_icc_init(pcie);
+	ret = qcom_pcie_cmn_icc_get_resource(pcie->pci, pcie->icc_mem);
+	if (ret)
+		goto err_pm_runtime_put;
+
+	ret = qcom_pcie_cmn_icc_init(pcie->pci, pcie->icc_mem);
 	if (ret)
 		goto err_pm_runtime_put;
 
@@ -1546,7 +1495,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 		goto err_phy_exit;
 	}
 
-	qcom_pcie_icc_update(pcie);
+	qcom_pcie_cmn_icc_update(pcie->pci, pcie->icc_mem);
 
 	if (pcie->mhi)
 		qcom_pcie_init_debugfs(pcie);
@@ -1613,7 +1562,7 @@ static int qcom_pcie_resume_noirq(struct device *dev)
 		pcie->suspended = false;
 	}
 
-	qcom_pcie_icc_update(pcie);
+	qcom_pcie_cmn_icc_update(pcie->pci, pcie->icc_mem);
 
 	return 0;
 }
-- 
2.43.2