From 5aa180974e4d53f397f7d02bbce2c1105e8e538b Mon Sep 17 00:00:00 2001
From: Bjorn Andersson <bjorn.andersson@linaro.org>
Date: Tue, 28 May 2019 17:57:08 -0700
Subject: [PATCH 1/4] PCI: qcom: Use clk bulk API for 2.4.0 controllers

Before introducing the QCS404 platform, which uses the same PCIe
controller as IPQ4019, migrate this to use the bulk clock API, in order
to make the error paths slighly cleaner.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Niklas Cassel <niklas.cassel@linaro.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 53 ++++++++------------------
 1 file changed, 16 insertions(+), 37 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 0ed235d560e32..23dc012125084 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -112,10 +112,10 @@ struct qcom_pcie_resources_2_3_2 {
 	struct regulator_bulk_data supplies[QCOM_PCIE_2_3_2_MAX_SUPPLY];
 };
 
+#define QCOM_PCIE_2_4_0_MAX_CLOCKS	3
 struct qcom_pcie_resources_2_4_0 {
-	struct clk *aux_clk;
-	struct clk *master_clk;
-	struct clk *slave_clk;
+	struct clk_bulk_data clks[QCOM_PCIE_2_4_0_MAX_CLOCKS];
+	int num_clks;
 	struct reset_control *axi_m_reset;
 	struct reset_control *axi_s_reset;
 	struct reset_control *pipe_reset;
@@ -638,18 +638,17 @@ static int qcom_pcie_get_resources_2_4_0(struct qcom_pcie *pcie)
 	struct qcom_pcie_resources_2_4_0 *res = &pcie->res.v2_4_0;
 	struct dw_pcie *pci = pcie->pci;
 	struct device *dev = pci->dev;
+	int ret;
 
-	res->aux_clk = devm_clk_get(dev, "aux");
-	if (IS_ERR(res->aux_clk))
-		return PTR_ERR(res->aux_clk);
+	res->clks[0].id = "aux";
+	res->clks[1].id = "master_bus";
+	res->clks[2].id = "slave_bus";
 
-	res->master_clk = devm_clk_get(dev, "master_bus");
-	if (IS_ERR(res->master_clk))
-		return PTR_ERR(res->master_clk);
+	res->num_clks = 3;
 
-	res->slave_clk = devm_clk_get(dev, "slave_bus");
-	if (IS_ERR(res->slave_clk))
-		return PTR_ERR(res->slave_clk);
+	ret = devm_clk_bulk_get(dev, res->num_clks, res->clks);
+	if (ret < 0)
+		return ret;
 
 	res->axi_m_reset = devm_reset_control_get_exclusive(dev, "axi_m");
 	if (IS_ERR(res->axi_m_reset))
@@ -719,9 +718,7 @@ static void qcom_pcie_deinit_2_4_0(struct qcom_pcie *pcie)
 	reset_control_assert(res->axi_m_sticky_reset);
 	reset_control_assert(res->pwr_reset);
 	reset_control_assert(res->ahb_reset);
-	clk_disable_unprepare(res->aux_clk);
-	clk_disable_unprepare(res->master_clk);
-	clk_disable_unprepare(res->slave_clk);
+	clk_bulk_disable_unprepare(res->num_clks, res->clks);
 }
 
 static int qcom_pcie_init_2_4_0(struct qcom_pcie *pcie)
@@ -850,23 +847,9 @@ static int qcom_pcie_init_2_4_0(struct qcom_pcie *pcie)
 
 	usleep_range(10000, 12000);
 
-	ret = clk_prepare_enable(res->aux_clk);
-	if (ret) {
-		dev_err(dev, "cannot prepare/enable iface clock\n");
-		goto err_clk_aux;
-	}
-
-	ret = clk_prepare_enable(res->master_clk);
-	if (ret) {
-		dev_err(dev, "cannot prepare/enable core clock\n");
-		goto err_clk_axi_m;
-	}
-
-	ret = clk_prepare_enable(res->slave_clk);
-	if (ret) {
-		dev_err(dev, "cannot prepare/enable phy clock\n");
-		goto err_clk_axi_s;
-	}
+	ret = clk_bulk_prepare_enable(res->num_clks, res->clks);
+	if (ret)
+		goto err_clks;
 
 	/* enable PCIe clocks and resets */
 	val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
@@ -891,11 +874,7 @@ static int qcom_pcie_init_2_4_0(struct qcom_pcie *pcie)
 
 	return 0;
 
-err_clk_axi_s:
-	clk_disable_unprepare(res->master_clk);
-err_clk_axi_m:
-	clk_disable_unprepare(res->aux_clk);
-err_clk_aux:
+err_clks:
 	reset_control_assert(res->ahb_reset);
 err_rst_ahb:
 	reset_control_assert(res->pwr_reset);

From 29a50257a9d6d16320bc5e2fc1b15e0f2b2eb7cf Mon Sep 17 00:00:00 2001
From: Bjorn Andersson <bjorn.andersson@linaro.org>
Date: Tue, 28 May 2019 17:57:09 -0700
Subject: [PATCH 2/4] dt-bindings: PCI: qcom: Add QCS404 to the binding

The Qualcomm QCS404 platform contains a PCIe controller, add this to the
Qualcomm PCI binding document. The controller is the same version as the
one used in IPQ4019, but the PHY part is described separately, hence the
difference in clocks and resets.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
---
 .../devicetree/bindings/pci/qcom,pcie.txt     | 25 +++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie.txt b/Documentation/devicetree/bindings/pci/qcom,pcie.txt
index 1fd703bd73e0f..ada80b01bf0c6 100644
--- a/Documentation/devicetree/bindings/pci/qcom,pcie.txt
+++ b/Documentation/devicetree/bindings/pci/qcom,pcie.txt
@@ -10,6 +10,7 @@
 			- "qcom,pcie-msm8996" for msm8996 or apq8096
 			- "qcom,pcie-ipq4019" for ipq4019
 			- "qcom,pcie-ipq8074" for ipq8074
+			- "qcom,pcie-qcs404" for qcs404
 
 - reg:
 	Usage: required
@@ -116,6 +117,15 @@
 			- "ahb"		AHB clock
 			- "aux"		Auxiliary clock
 
+- clock-names:
+	Usage: required for qcs404
+	Value type: <stringlist>
+	Definition: Should contain the following entries
+			- "iface"	AHB clock
+			- "aux"		Auxiliary clock
+			- "master_bus"	AXI Master clock
+			- "slave_bus"	AXI Slave clock
+
 - resets:
 	Usage: required
 	Value type: <prop-encoded-array>
@@ -167,6 +177,17 @@
 			- "ahb"			AHB Reset
 			- "axi_m_sticky"	AXI Master Sticky reset
 
+- reset-names:
+	Usage: required for qcs404
+	Value type: <stringlist>
+	Definition: Should contain the following entries
+			- "axi_m"		AXI Master reset
+			- "axi_s"		AXI Slave reset
+			- "axi_m_sticky"	AXI Master Sticky reset
+			- "pipe_sticky"		PIPE sticky reset
+			- "pwr"			PWR reset
+			- "ahb"			AHB reset
+
 - power-domains:
 	Usage: required for apq8084 and msm8996/apq8096
 	Value type: <prop-encoded-array>
@@ -195,12 +216,12 @@
 	Definition: A phandle to the PCIe endpoint power supply
 
 - phys:
-	Usage: required for apq8084
+	Usage: required for apq8084 and qcs404
 	Value type: <phandle>
 	Definition: List of phandle(s) as listed in phy-names property
 
 - phy-names:
-	Usage: required for apq8084
+	Usage: required for apq8084 and qcs404
 	Value type: <stringlist>
 	Definition: Should contain "pciephy"
 

From 67021ae0bbe941dca6605efab52089bcbf245fb5 Mon Sep 17 00:00:00 2001
From: Bjorn Andersson <bjorn.andersson@linaro.org>
Date: Tue, 28 May 2019 17:57:10 -0700
Subject: [PATCH 3/4] PCI: qcom: Add QCS404 PCIe controller support

The QCS404 platform contains a PCIe version 2.4.0 controller and a
Qualcomm PCIe2 PHY. The driver already supports version 2.4.0, for the
IPQ4019, but this support touches clocks and resets related to the PHY
as well and there's no upstream driver for the PHY.

On QCS404 we must initialize the PHY, so a separate PHY driver is
implemented to take care of this and the controller driver is updated to
not require the PHY related resources. This is done by relying on the
fact that operations in both the clock and reset framework are NOPs when
passed NULL, so we can isolate this change to only the
qcom_pcie_get_resources_2_4_0() function.

For QCS404 we also need to enable the AHB (iface) clock, in order to
access the register space of the controller, but as this is not part of
the IPQ4019 DT binding this is only added for new users of the 2.4.0
controller.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Niklas Cassel <niklas.cassel@linaro.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 64 +++++++++++++++-----------
 1 file changed, 38 insertions(+), 26 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 23dc012125084..da5dd3639a49e 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -112,7 +112,7 @@ struct qcom_pcie_resources_2_3_2 {
 	struct regulator_bulk_data supplies[QCOM_PCIE_2_3_2_MAX_SUPPLY];
 };
 
-#define QCOM_PCIE_2_4_0_MAX_CLOCKS	3
+#define QCOM_PCIE_2_4_0_MAX_CLOCKS	4
 struct qcom_pcie_resources_2_4_0 {
 	struct clk_bulk_data clks[QCOM_PCIE_2_4_0_MAX_CLOCKS];
 	int num_clks;
@@ -638,13 +638,16 @@ static int qcom_pcie_get_resources_2_4_0(struct qcom_pcie *pcie)
 	struct qcom_pcie_resources_2_4_0 *res = &pcie->res.v2_4_0;
 	struct dw_pcie *pci = pcie->pci;
 	struct device *dev = pci->dev;
+	bool is_ipq = of_device_is_compatible(dev->of_node, "qcom,pcie-ipq4019");
 	int ret;
 
 	res->clks[0].id = "aux";
 	res->clks[1].id = "master_bus";
 	res->clks[2].id = "slave_bus";
+	res->clks[3].id = "iface";
 
-	res->num_clks = 3;
+	/* qcom,pcie-ipq4019 is defined without "iface" */
+	res->num_clks = is_ipq ? 3 : 4;
 
 	ret = devm_clk_bulk_get(dev, res->num_clks, res->clks);
 	if (ret < 0)
@@ -658,27 +661,33 @@ static int qcom_pcie_get_resources_2_4_0(struct qcom_pcie *pcie)
 	if (IS_ERR(res->axi_s_reset))
 		return PTR_ERR(res->axi_s_reset);
 
-	res->pipe_reset = devm_reset_control_get_exclusive(dev, "pipe");
-	if (IS_ERR(res->pipe_reset))
-		return PTR_ERR(res->pipe_reset);
-
-	res->axi_m_vmid_reset = devm_reset_control_get_exclusive(dev,
-								 "axi_m_vmid");
-	if (IS_ERR(res->axi_m_vmid_reset))
-		return PTR_ERR(res->axi_m_vmid_reset);
-
-	res->axi_s_xpu_reset = devm_reset_control_get_exclusive(dev,
-								"axi_s_xpu");
-	if (IS_ERR(res->axi_s_xpu_reset))
-		return PTR_ERR(res->axi_s_xpu_reset);
-
-	res->parf_reset = devm_reset_control_get_exclusive(dev, "parf");
-	if (IS_ERR(res->parf_reset))
-		return PTR_ERR(res->parf_reset);
-
-	res->phy_reset = devm_reset_control_get_exclusive(dev, "phy");
-	if (IS_ERR(res->phy_reset))
-		return PTR_ERR(res->phy_reset);
+	if (is_ipq) {
+		/*
+		 * These resources relates to the PHY or are secure clocks, but
+		 * are controlled here for IPQ4019
+		 */
+		res->pipe_reset = devm_reset_control_get_exclusive(dev, "pipe");
+		if (IS_ERR(res->pipe_reset))
+			return PTR_ERR(res->pipe_reset);
+
+		res->axi_m_vmid_reset = devm_reset_control_get_exclusive(dev,
+									 "axi_m_vmid");
+		if (IS_ERR(res->axi_m_vmid_reset))
+			return PTR_ERR(res->axi_m_vmid_reset);
+
+		res->axi_s_xpu_reset = devm_reset_control_get_exclusive(dev,
+									"axi_s_xpu");
+		if (IS_ERR(res->axi_s_xpu_reset))
+			return PTR_ERR(res->axi_s_xpu_reset);
+
+		res->parf_reset = devm_reset_control_get_exclusive(dev, "parf");
+		if (IS_ERR(res->parf_reset))
+			return PTR_ERR(res->parf_reset);
+
+		res->phy_reset = devm_reset_control_get_exclusive(dev, "phy");
+		if (IS_ERR(res->phy_reset))
+			return PTR_ERR(res->phy_reset);
+	}
 
 	res->axi_m_sticky_reset = devm_reset_control_get_exclusive(dev,
 								   "axi_m_sticky");
@@ -698,9 +707,11 @@ static int qcom_pcie_get_resources_2_4_0(struct qcom_pcie *pcie)
 	if (IS_ERR(res->ahb_reset))
 		return PTR_ERR(res->ahb_reset);
 
-	res->phy_ahb_reset = devm_reset_control_get_exclusive(dev, "phy_ahb");
-	if (IS_ERR(res->phy_ahb_reset))
-		return PTR_ERR(res->phy_ahb_reset);
+	if (is_ipq) {
+		res->phy_ahb_reset = devm_reset_control_get_exclusive(dev, "phy_ahb");
+		if (IS_ERR(res->phy_ahb_reset))
+			return PTR_ERR(res->phy_ahb_reset);
+	}
 
 	return 0;
 }
@@ -1268,6 +1279,7 @@ static const struct of_device_id qcom_pcie_match[] = {
 	{ .compatible = "qcom,pcie-msm8996", .data = &ops_2_3_2 },
 	{ .compatible = "qcom,pcie-ipq8074", .data = &ops_2_3_3 },
 	{ .compatible = "qcom,pcie-ipq4019", .data = &ops_2_4_0 },
+	{ .compatible = "qcom,pcie-qcs404", .data = &ops_2_4_0 },
 	{ }
 };
 

From 64adde31c8e996a6db6f7a1a4131180e363aa9f2 Mon Sep 17 00:00:00 2001
From: Niklas Cassel <niklas.cassel@linaro.org>
Date: Wed, 29 May 2019 11:43:52 +0200
Subject: [PATCH 4/4] PCI: qcom: Ensure that PERST is asserted for at least 100
 ms

Currently, there is only a 1 ms sleep after asserting PERST.

Reading the datasheets for different endpoints, some require PERST to be
asserted for 10 ms in order for the endpoint to perform a reset, others
require it to be asserted for 50 ms.

Several SoCs using this driver uses PCIe Mini Card, where we don't know
what endpoint will be plugged in.

The PCI Express Card Electromechanical Specification r2.0, section
2.2, "PERST# Signal" specifies:

"On power up, the deassertion of PERST# is delayed 100 ms (TPVPERL) from
the power rails achieving specified operating limits."

Add a sleep of 100 ms before deasserting PERST, in order to ensure that
we are compliant with the spec.

Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver")
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Cc: stable@vger.kernel.org # 4.5+
---
 drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index da5dd3639a49e..7e581748ee9f1 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -178,6 +178,8 @@ static void qcom_ep_reset_assert(struct qcom_pcie *pcie)
 
 static void qcom_ep_reset_deassert(struct qcom_pcie *pcie)
 {
+	/* Ensure that PERST has been asserted for at least 100 ms */
+	msleep(100);
 	gpiod_set_value_cansleep(pcie->reset, 0);
 	usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500);
 }