[PATCHv5 0/6] PCI: layerscape: Add power management support

[PATCHv5 0/6] PCI: layerscape: Add power management support

[Zhiqiang Hou]

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

This patch series is to add PCIe power management support for NXP
Layerscape platforms.

Hou Zhiqiang (6):
  PCI: layerscape: Change to use the DWC common link-up check function
  dt-bindings: pci: layerscape-pci: Add a optional property big-endian
  arm64: dts: layerscape: Add big-endian property for PCIe nodes
  dt-bindings: pci: layerscape-pci: Update the description of SCFG
    property
  arm64: dts: ls1043a: Add SCFG phandle for PCIe nodes
  PCI: layerscape: Add power management support

 .../bindings/pci/layerscape-pci.txt           |   6 +-
 .../arm64/boot/dts/freescale/fsl-ls1012a.dtsi |   1 +
 .../arm64/boot/dts/freescale/fsl-ls1043a.dtsi |   6 +
 .../arm64/boot/dts/freescale/fsl-ls1046a.dtsi |   3 +
 drivers/pci/controller/dwc/pci-layerscape.c   | 450 ++++++++++++++----
 drivers/pci/controller/dwc/pcie-designware.h  |   1 +
 6 files changed, 370 insertions(+), 97 deletions(-)

-- 
2.17.1

[PATCHv5 1/6] PCI: layerscape: Change to use the DWC common link-up check function

[Zhiqiang Hou]

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

The current Layerscape PCIe driver directly uses the physical layer
LTSSM code to check the link-up state, which treats the > L0 states
as link-up. This is not correct, since there is not explicit map
between link-up state and LTSSM. So this patch changes to use the
DWC common link-up check function.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
V5:
 - No change

 drivers/pci/controller/dwc/pci-layerscape.c | 140 ++------------------
 1 file changed, 10 insertions(+), 130 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
index 5b9c625df7b8..71911ca4c589 100644
--- a/drivers/pci/controller/dwc/pci-layerscape.c
+++ b/drivers/pci/controller/dwc/pci-layerscape.c
@@ -22,12 +22,6 @@
 
 #include "pcie-designware.h"
 
-/* PEX1/2 Misc Ports Status Register */
-#define SCFG_PEXMSCPORTSR(pex_idx)	(0x94 + (pex_idx) * 4)
-#define LTSSM_STATE_SHIFT	20
-#define LTSSM_STATE_MASK	0x3f
-#define LTSSM_PCIE_L0		0x11 /* L0 state */
-
 /* PEX Internal Configuration Registers */
 #define PCIE_STRFMR1		0x71c /* Symbol Timer & Filter Mask Register1 */
 #define PCIE_ABSERR		0x8d0 /* Bridge Slave Error Response Register */
@@ -36,19 +30,12 @@
 #define PCIE_IATU_NUM		6
 
 struct ls_pcie_drvdata {
-	u32 lut_offset;
-	u32 ltssm_shift;
-	u32 lut_dbg;
 	const struct dw_pcie_host_ops *ops;
-	const struct dw_pcie_ops *dw_pcie_ops;
 };
 
 struct ls_pcie {
 	struct dw_pcie *pci;
-	void __iomem *lut;
-	struct regmap *scfg;
 	const struct ls_pcie_drvdata *drvdata;
-	int index;
 };
 
 #define to_ls_pcie(x)	dev_get_drvdata((x)->dev)
@@ -83,38 +70,6 @@ static void ls_pcie_drop_msg_tlp(struct ls_pcie *pcie)
 	iowrite32(val, pci->dbi_base + PCIE_STRFMR1);
 }
 
-static int ls1021_pcie_link_up(struct dw_pcie *pci)
-{
-	u32 state;
-	struct ls_pcie *pcie = to_ls_pcie(pci);
-
-	if (!pcie->scfg)
-		return 0;
-
-	regmap_read(pcie->scfg, SCFG_PEXMSCPORTSR(pcie->index), &state);
-	state = (state >> LTSSM_STATE_SHIFT) & LTSSM_STATE_MASK;
-
-	if (state < LTSSM_PCIE_L0)
-		return 0;
-
-	return 1;
-}
-
-static int ls_pcie_link_up(struct dw_pcie *pci)
-{
-	struct ls_pcie *pcie = to_ls_pcie(pci);
-	u32 state;
-
-	state = (ioread32(pcie->lut + pcie->drvdata->lut_dbg) >>
-		 pcie->drvdata->ltssm_shift) &
-		 LTSSM_STATE_MASK;
-
-	if (state < LTSSM_PCIE_L0)
-		return 0;
-
-	return 1;
-}
-
 /* Forward error response of outbound non-posted requests */
 static void ls_pcie_fix_error_response(struct ls_pcie *pcie)
 {
@@ -139,96 +94,24 @@ static int ls_pcie_host_init(struct pcie_port *pp)
 	return 0;
 }
 
-static int ls1021_pcie_host_init(struct pcie_port *pp)
-{
-	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
-	struct ls_pcie *pcie = to_ls_pcie(pci);
-	struct device *dev = pci->dev;
-	u32 index[2];
-	int ret;
-
-	pcie->scfg = syscon_regmap_lookup_by_phandle(dev->of_node,
-						     "fsl,pcie-scfg");
-	if (IS_ERR(pcie->scfg)) {
-		ret = PTR_ERR(pcie->scfg);
-		dev_err(dev, "No syscfg phandle specified\n");
-		pcie->scfg = NULL;
-		return ret;
-	}
-
-	if (of_property_read_u32_array(dev->of_node,
-				       "fsl,pcie-scfg", index, 2)) {
-		pcie->scfg = NULL;
-		return -EINVAL;
-	}
-	pcie->index = index[1];
-
-	return ls_pcie_host_init(pp);
-}
-
-static const struct dw_pcie_host_ops ls1021_pcie_host_ops = {
-	.host_init = ls1021_pcie_host_init,
-};
-
 static const struct dw_pcie_host_ops ls_pcie_host_ops = {
 	.host_init = ls_pcie_host_init,
 };
 
-static const struct dw_pcie_ops dw_ls1021_pcie_ops = {
-	.link_up = ls1021_pcie_link_up,
-};
-
-static const struct dw_pcie_ops dw_ls_pcie_ops = {
-	.link_up = ls_pcie_link_up,
-};
-
-static const struct ls_pcie_drvdata ls1021_drvdata = {
-	.ops = &ls1021_pcie_host_ops,
-	.dw_pcie_ops = &dw_ls1021_pcie_ops,
-};
-
-static const struct ls_pcie_drvdata ls1043_drvdata = {
-	.lut_offset = 0x10000,
-	.ltssm_shift = 24,
-	.lut_dbg = 0x7fc,
+static const struct ls_pcie_drvdata layerscape_drvdata = {
 	.ops = &ls_pcie_host_ops,
-	.dw_pcie_ops = &dw_ls_pcie_ops,
-};
-
-static const struct ls_pcie_drvdata ls1046_drvdata = {
-	.lut_offset = 0x80000,
-	.ltssm_shift = 24,
-	.lut_dbg = 0x407fc,
-	.ops = &ls_pcie_host_ops,
-	.dw_pcie_ops = &dw_ls_pcie_ops,
-};
-
-static const struct ls_pcie_drvdata ls2080_drvdata = {
-	.lut_offset = 0x80000,
-	.ltssm_shift = 0,
-	.lut_dbg = 0x7fc,
-	.ops = &ls_pcie_host_ops,
-	.dw_pcie_ops = &dw_ls_pcie_ops,
-};
-
-static const struct ls_pcie_drvdata ls2088_drvdata = {
-	.lut_offset = 0x80000,
-	.ltssm_shift = 0,
-	.lut_dbg = 0x407fc,
-	.ops = &ls_pcie_host_ops,
-	.dw_pcie_ops = &dw_ls_pcie_ops,
 };
 
 static const struct of_device_id ls_pcie_of_match[] = {
-	{ .compatible = "fsl,ls1012a-pcie", .data = &ls1046_drvdata },
-	{ .compatible = "fsl,ls1021a-pcie", .data = &ls1021_drvdata },
-	{ .compatible = "fsl,ls1028a-pcie", .data = &ls2088_drvdata },
-	{ .compatible = "fsl,ls1043a-pcie", .data = &ls1043_drvdata },
-	{ .compatible = "fsl,ls1046a-pcie", .data = &ls1046_drvdata },
-	{ .compatible = "fsl,ls2080a-pcie", .data = &ls2080_drvdata },
-	{ .compatible = "fsl,ls2085a-pcie", .data = &ls2080_drvdata },
-	{ .compatible = "fsl,ls2088a-pcie", .data = &ls2088_drvdata },
-	{ .compatible = "fsl,ls1088a-pcie", .data = &ls2088_drvdata },
+	{ .compatible = "fsl,ls1012a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1021a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1028a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1043a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1046a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls2080a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls2085a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls2088a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1088a-pcie", .data = &layerscape_drvdata },
 	{ },
 };
 
@@ -250,7 +133,6 @@ static int ls_pcie_probe(struct platform_device *pdev)
 	pcie->drvdata = of_device_get_match_data(dev);
 
 	pci->dev = dev;
-	pci->ops = pcie->drvdata->dw_pcie_ops;
 	pci->pp.ops = pcie->drvdata->ops;
 
 	pcie->pci = pci;
@@ -260,8 +142,6 @@ static int ls_pcie_probe(struct platform_device *pdev)
 	if (IS_ERR(pci->dbi_base))
 		return PTR_ERR(pci->dbi_base);
 
-	pcie->lut = pci->dbi_base + pcie->drvdata->lut_offset;
-
 	if (!ls_pcie_is_bridge(pcie))
 		return -ENODEV;
 
-- 
2.17.1

[PATCHv5 2/6] dt-bindings: pci: layerscape-pci: Add a optional property big-endian

[Zhiqiang Hou]

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

This property is to indicate the endianness when accessing the
PEX_LUT and PF register block, so if these registers are
implemented in big-endian, specify this property.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
---
V5:
 - No change

 Documentation/devicetree/bindings/pci/layerscape-pci.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/layerscape-pci.txt b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
index 6d898dd4a8e2..d633c1fabdb4 100644
--- a/Documentation/devicetree/bindings/pci/layerscape-pci.txt
+++ b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
@@ -40,6 +40,10 @@ Required properties:
   of the data transferred from/to the IP block. This can avoid the software
   cache flush/invalid actions, and improve the performance significantly.
 
+Optional properties:
+- big-endian: If the PEX_LUT and PF register block is in big-endian, specify
+  this property.
+
 Example:
 
 	pcie@3400000 {
-- 
2.17.1

[PATCHv5 3/6] arm64: dts: layerscape: Add big-endian property for PCIe nodes

[Zhiqiang Hou]

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

Add the big-endian property for LS1012A, LS1043A and LS1046A
PCIe devicetree nodes.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
---
V5:
 - No change

 arch/arm64/boot/dts/freescale/fsl-ls1012a.dtsi | 1 +
 arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi | 3 +++
 arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi | 3 +++
 3 files changed, 7 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1012a.dtsi b/arch/arm64/boot/dts/freescale/fsl-ls1012a.dtsi
index 9058cfa4980f..ac23e938fd1d 100644
--- a/arch/arm64/boot/dts/freescale/fsl-ls1012a.dtsi
+++ b/arch/arm64/boot/dts/freescale/fsl-ls1012a.dtsi
@@ -542,6 +542,7 @@
 					<0000 0 0 2 &gic 0 111 IRQ_TYPE_LEVEL_HIGH>,
 					<0000 0 0 3 &gic 0 112 IRQ_TYPE_LEVEL_HIGH>,
 					<0000 0 0 4 &gic 0 113 IRQ_TYPE_LEVEL_HIGH>;
+			big-endian;
 			status = "disabled";
 		};
 
diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi b/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
index 28c51e521cb2..46826752a691 100644
--- a/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
+++ b/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
@@ -890,6 +890,7 @@
 					<0000 0 0 2 &gic 0 111 0x4>,
 					<0000 0 0 3 &gic 0 112 0x4>,
 					<0000 0 0 4 &gic 0 113 0x4>;
+			big-endian;
 			status = "disabled";
 		};
 
@@ -916,6 +917,7 @@
 					<0000 0 0 2 &gic 0 121 0x4>,
 					<0000 0 0 3 &gic 0 122 0x4>,
 					<0000 0 0 4 &gic 0 123 0x4>;
+			big-endian;
 			status = "disabled";
 		};
 
@@ -942,6 +944,7 @@
 					<0000 0 0 2 &gic 0 155 0x4>,
 					<0000 0 0 3 &gic 0 156 0x4>,
 					<0000 0 0 4 &gic 0 157 0x4>;
+			big-endian;
 			status = "disabled";
 		};
 
diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi b/arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi
index 39458305e333..f21ee7825d40 100644
--- a/arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi
+++ b/arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi
@@ -794,6 +794,7 @@
 					<0000 0 0 2 &gic GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>,
 					<0000 0 0 3 &gic GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>,
 					<0000 0 0 4 &gic GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+			big-endian;
 			status = "disabled";
 		};
 
@@ -830,6 +831,7 @@
 					<0000 0 0 2 &gic GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>,
 					<0000 0 0 3 &gic GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>,
 					<0000 0 0 4 &gic GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>;
+			big-endian;
 			status = "disabled";
 		};
 
@@ -866,6 +868,7 @@
 					<0000 0 0 2 &gic GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>,
 					<0000 0 0 3 &gic GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>,
 					<0000 0 0 4 &gic GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
+			big-endian;
 			status = "disabled";
 		};
 
-- 
2.17.1

[PATCHv5 4/6] dt-bindings: pci: layerscape-pci: Update the description of SCFG property

[Zhiqiang Hou]

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

Update the description of the second entry of 'fsl,pcie-scfg' property,
as the LS1043A PCIe controller also has some control registers in SCFG
block, while it has 3 controllers.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
---
V5:
 - No change

 Documentation/devicetree/bindings/pci/layerscape-pci.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/pci/layerscape-pci.txt b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
index d633c1fabdb4..8231f6729385 100644
--- a/Documentation/devicetree/bindings/pci/layerscape-pci.txt
+++ b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
@@ -34,7 +34,7 @@ Required properties:
   "intr": The interrupt that is asserted for controller interrupts
 - fsl,pcie-scfg: Must include two entries.
   The first entry must be a link to the SCFG device node
-  The second entry must be '0' or '1' based on physical PCIe controller index.
+  The second entry is the physical PCIe controller index starting from '0'.
   This is used to get SCFG PEXN registers
 - dma-coherent: Indicates that the hardware IP block can ensure the coherency
   of the data transferred from/to the IP block. This can avoid the software
-- 
2.17.1

[PATCHv5 5/6] arm64: dts: ls1043a: Add SCFG phandle for PCIe nodes

[Zhiqiang Hou]

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

The LS1043A PCIe controller has some control registers
in SCFG block, so add the SCFG phandle for each PCIe
controller DT node.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
---
V5:
 - No change

 arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi b/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
index 46826752a691..704e9e249729 100644
--- a/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
+++ b/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
@@ -875,6 +875,7 @@
 			interrupts = <0 118 0x4>, /* controller interrupt */
 				     <0 117 0x4>; /* PME interrupt */
 			interrupt-names = "intr", "pme";
+			fsl,pcie-scfg = <&scfg 0>;
 			#address-cells = <3>;
 			#size-cells = <2>;
 			device_type = "pci";
@@ -902,6 +903,7 @@
 			interrupts = <0 128 0x4>,
 				     <0 127 0x4>;
 			interrupt-names = "intr", "pme";
+			fsl,pcie-scfg = <&scfg 1>;
 			#address-cells = <3>;
 			#size-cells = <2>;
 			device_type = "pci";
@@ -929,6 +931,7 @@
 			interrupts = <0 162 0x4>,
 				     <0 161 0x4>;
 			interrupt-names = "intr", "pme";
+			fsl,pcie-scfg = <&scfg 2>;
 			#address-cells = <3>;
 			#size-cells = <2>;
 			device_type = "pci";
-- 
2.17.1

[PATCHv5 6/6] PCI: layerscape: Add power management support

[Zhiqiang Hou]

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

Add PME_Turn_Off/PME_TO_Ack handshake sequence, and finally
put the PCIe controller into D3 state after the L2/L3 ready
state transition process completion.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
---
V5:
 - Fix a typo of the parameter given to function dw_pcie_setup_rc()

 drivers/pci/controller/dwc/pci-layerscape.c  | 382 ++++++++++++++++++-
 drivers/pci/controller/dwc/pcie-designware.h |   1 +
 2 files changed, 381 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
index 71911ca4c589..868e18b12e4a 100644
--- a/drivers/pci/controller/dwc/pci-layerscape.c
+++ b/drivers/pci/controller/dwc/pci-layerscape.c
@@ -3,13 +3,16 @@
  * PCIe host controller driver for Freescale Layerscape SoCs
  *
  * Copyright (C) 2014 Freescale Semiconductor.
+ * Copyright 2020 NXP
  *
  * Author: Minghuan Lian <Minghuan.Lian@freescale.com>
  */
 
+#include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/init.h>
+#include <linux/iopoll.h>
 #include <linux/of_pci.h>
 #include <linux/of_platform.h>
 #include <linux/of_irq.h>
@@ -27,17 +30,60 @@
 #define PCIE_ABSERR		0x8d0 /* Bridge Slave Error Response Register */
 #define PCIE_ABSERR_SETTING	0x9401 /* Forward error of non-posted request */
 
+/* PF Message Command Register */
+#define LS_PCIE_PF_MCR		0x2c
+#define PF_MCR_PTOMR		BIT(0)
+#define PF_MCR_EXL2S		BIT(1)
+
+/* LS1021A PEXn PM Write Control Register */
+#define SCFG_PEXPMWRCR(idx)	(0x5c + (idx) * 0x64)
+#define PMXMTTURNOFF		BIT(31)
+#define SCFG_PEXSFTRSTCR	0x190
+#define PEXSR(idx)		BIT(idx)
+
+/* LS1043A PEX PME control register */
+#define SCFG_PEXPMECR		0x144
+#define PEXPME(idx)		BIT(31 - (idx) * 4)
+
+/* LS1043A PEX LUT debug register */
+#define LS_PCIE_LDBG	0x7fc
+#define LDBG_SR		BIT(30)
+#define LDBG_WE		BIT(31)
+
 #define PCIE_IATU_NUM		6
 
+#define LS_PCIE_IS_L2(v)	\
+	(((v) & PORT_LOGIC_LTSSM_STATE_MASK) == PORT_LOGIC_LTSSM_STATE_L2)
+
+struct ls_pcie;
+
+struct ls_pcie_host_pm_ops {
+	int (*pm_init)(struct ls_pcie *pcie);
+	void (*send_turn_off_message)(struct ls_pcie *pcie);
+	void (*exit_from_l2)(struct ls_pcie *pcie);
+};
+
 struct ls_pcie_drvdata {
+	const u32 pf_off;
+	const u32 lut_off;
 	const struct dw_pcie_host_ops *ops;
+	const struct ls_pcie_host_pm_ops *pm_ops;
 };
 
 struct ls_pcie {
 	struct dw_pcie *pci;
 	const struct ls_pcie_drvdata *drvdata;
+	void __iomem *pf_base;
+	void __iomem *lut_base;
+	bool big_endian;
+	bool ep_presence;
+	bool pm_support;
+	struct regmap *scfg;
+	int index;
 };
 
+#define ls_pcie_lut_readl_addr(addr)	ls_pcie_lut_readl(pcie, addr)
+#define ls_pcie_pf_readl_addr(addr)	ls_pcie_pf_readl(pcie, addr)
 #define to_ls_pcie(x)	dev_get_drvdata((x)->dev)
 
 static bool ls_pcie_is_bridge(struct ls_pcie *pcie)
@@ -78,6 +124,210 @@ static void ls_pcie_fix_error_response(struct ls_pcie *pcie)
 	iowrite32(PCIE_ABSERR_SETTING, pci->dbi_base + PCIE_ABSERR);
 }
 
+static u32 ls_pcie_lut_readl(struct ls_pcie *pcie, u32 off)
+{
+	if (pcie->big_endian)
+		return ioread32be(pcie->lut_base + off);
+
+	return ioread32(pcie->lut_base + off);
+}
+
+static void ls_pcie_lut_writel(struct ls_pcie *pcie, u32 off, u32 val)
+{
+	if (pcie->big_endian)
+		return iowrite32be(val, pcie->lut_base + off);
+
+	return iowrite32(val, pcie->lut_base + off);
+
+}
+
+static u32 ls_pcie_pf_readl(struct ls_pcie *pcie, u32 off)
+{
+	if (pcie->big_endian)
+		return ioread32be(pcie->pf_base + off);
+
+	return ioread32(pcie->pf_base + off);
+}
+
+static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val)
+{
+	if (pcie->big_endian)
+		return iowrite32be(val, pcie->pf_base + off);
+
+	return iowrite32(val, pcie->pf_base + off);
+
+}
+
+static void ls_pcie_send_turnoff_msg(struct ls_pcie *pcie)
+{
+	u32 val;
+	int ret;
+
+	val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
+	val |= PF_MCR_PTOMR;
+	ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
+
+	ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
+				 val, !(val & PF_MCR_PTOMR), 100, 10000);
+	if (ret)
+		dev_info(pcie->pci->dev, "poll turn off message timeout\n");
+}
+
+static void ls1021a_pcie_send_turnoff_msg(struct ls_pcie *pcie)
+{
+	u32 val;
+
+	if (!pcie->scfg) {
+		dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
+		return;
+	}
+
+	/* Send Turn_off message */
+	regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
+	val |= PMXMTTURNOFF;
+	regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
+
+	mdelay(10);
+
+	/* Clear Turn_off message */
+	regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
+	val &= ~PMXMTTURNOFF;
+	regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
+}
+
+static void ls1043a_pcie_send_turnoff_msg(struct ls_pcie *pcie)
+{
+	u32 val;
+
+	if (!pcie->scfg) {
+		dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
+		return;
+	}
+
+	/* Send Turn_off message */
+	regmap_read(pcie->scfg, SCFG_PEXPMECR, &val);
+	val |= PEXPME(pcie->index);
+	regmap_write(pcie->scfg, SCFG_PEXPMECR, val);
+
+	mdelay(10);
+
+	/* Clear Turn_off message */
+	regmap_read(pcie->scfg, SCFG_PEXPMECR, &val);
+	val &= ~PEXPME(pcie->index);
+	regmap_write(pcie->scfg, SCFG_PEXPMECR, val);
+}
+
+static void ls_pcie_exit_from_l2(struct ls_pcie *pcie)
+{
+	u32 val;
+	int ret;
+
+	val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
+	val |= PF_MCR_EXL2S;
+	ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
+
+	ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
+				 val, !(val & PF_MCR_EXL2S), 100, 10000);
+	if (ret)
+		dev_info(pcie->pci->dev, "poll exit L2 state timeout\n");
+}
+
+static void ls_pcie_retrain_link(struct ls_pcie *pcie)
+{
+	struct dw_pcie *pci = pcie->pci;
+	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u32 val;
+
+	val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL);
+	val |= PCI_EXP_LNKCTL_RL;
+	dw_pcie_writew_dbi(pci, offset + PCI_EXP_LNKCTL, val);
+}
+
+static void ls1021a_pcie_exit_from_l2(struct ls_pcie *pcie)
+{
+	u32 val;
+
+	regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
+	val |= PEXSR(pcie->index);
+	regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
+
+	regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
+	val &= ~PEXSR(pcie->index);
+	regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
+
+	mdelay(1);
+
+	ls_pcie_retrain_link(pcie);
+}
+static void ls1043a_pcie_exit_from_l2(struct ls_pcie *pcie)
+{
+	u32 val;
+
+	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+	val |= LDBG_WE;
+	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+	val |= LDBG_SR;
+	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+	val &= ~LDBG_SR;
+	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+	val &= ~LDBG_WE;
+	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	mdelay(1);
+
+	ls_pcie_retrain_link(pcie);
+}
+
+static int ls1021a_pcie_pm_init(struct ls_pcie *pcie)
+{
+	struct device *dev = pcie->pci->dev;
+	u32 index[2];
+	int ret;
+
+	pcie->scfg = syscon_regmap_lookup_by_phandle(dev->of_node,
+						     "fsl,pcie-scfg");
+	if (IS_ERR(pcie->scfg)) {
+		ret = PTR_ERR(pcie->scfg);
+		dev_err(dev, "No syscfg phandle specified\n");
+		pcie->scfg = NULL;
+		return ret;
+	}
+
+	ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
+					 index, 2);
+	if (ret) {
+		pcie->scfg = NULL;
+		return ret;
+	}
+
+	pcie->index = index[1];
+
+	return 0;
+}
+
+static int ls_pcie_pm_init(struct ls_pcie *pcie)
+{
+	return 0;
+}
+
+static void ls_pcie_set_dstate(struct ls_pcie *pcie, u32 dstate)
+{
+	struct dw_pcie *pci = pcie->pci;
+	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_PM);
+	u32 val;
+
+	val = dw_pcie_readw_dbi(pci, offset + PCI_PM_CTRL);
+	val &= ~PCI_PM_CTRL_STATE_MASK;
+	val |= dstate;
+	dw_pcie_writew_dbi(pci, offset + PCI_PM_CTRL, val);
+}
+
 static int ls_pcie_host_init(struct pcie_port *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -91,22 +341,63 @@ static int ls_pcie_host_init(struct pcie_port *pp)
 
 	ls_pcie_drop_msg_tlp(pcie);
 
+	if (dw_pcie_link_up(pci)) {
+		dev_dbg(pci->dev, "Endpoint is present\n");
+		pcie->ep_presence = true;
+	}
+
+	if (pcie->drvdata->pm_ops && pcie->drvdata->pm_ops->pm_init &&
+	    !pcie->drvdata->pm_ops->pm_init(pcie))
+		pcie->pm_support = true;
+
 	return 0;
 }
 
+static struct ls_pcie_host_pm_ops ls1021a_pcie_host_pm_ops = {
+	.pm_init = &ls1021a_pcie_pm_init,
+	.send_turn_off_message = &ls1021a_pcie_send_turnoff_msg,
+	.exit_from_l2 = &ls1021a_pcie_exit_from_l2,
+};
+
+static struct ls_pcie_host_pm_ops ls1043a_pcie_host_pm_ops = {
+	.pm_init = &ls1021a_pcie_pm_init,
+	.send_turn_off_message = &ls1043a_pcie_send_turnoff_msg,
+	.exit_from_l2 = &ls1043a_pcie_exit_from_l2,
+};
+
+static struct ls_pcie_host_pm_ops ls_pcie_host_pm_ops = {
+	.pm_init = &ls_pcie_pm_init,
+	.send_turn_off_message = &ls_pcie_send_turnoff_msg,
+	.exit_from_l2 = &ls_pcie_exit_from_l2,
+};
+
 static const struct dw_pcie_host_ops ls_pcie_host_ops = {
 	.host_init = ls_pcie_host_init,
 };
 
+static const struct ls_pcie_drvdata ls1021a_drvdata = {
+	.ops = &ls_pcie_host_ops,
+	.pm_ops = &ls1021a_pcie_host_pm_ops,
+};
+
+static const struct ls_pcie_drvdata ls1043a_drvdata = {
+	.ops = &ls_pcie_host_ops,
+	.lut_off = 0x10000,
+	.pm_ops = &ls1043a_pcie_host_pm_ops,
+};
+
 static const struct ls_pcie_drvdata layerscape_drvdata = {
 	.ops = &ls_pcie_host_ops,
+	.lut_off = 0x80000,
+	.pf_off = 0xc0000,
+	.pm_ops = &ls_pcie_host_pm_ops,
 };
 
 static const struct of_device_id ls_pcie_of_match[] = {
 	{ .compatible = "fsl,ls1012a-pcie", .data = &layerscape_drvdata },
-	{ .compatible = "fsl,ls1021a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1021a-pcie", .data = &ls1021a_drvdata },
 	{ .compatible = "fsl,ls1028a-pcie", .data = &layerscape_drvdata },
-	{ .compatible = "fsl,ls1043a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1043a-pcie", .data = &ls1043a_drvdata },
 	{ .compatible = "fsl,ls1046a-pcie", .data = &layerscape_drvdata },
 	{ .compatible = "fsl,ls2080a-pcie", .data = &layerscape_drvdata },
 	{ .compatible = "fsl,ls2085a-pcie", .data = &layerscape_drvdata },
@@ -142,6 +433,14 @@ static int ls_pcie_probe(struct platform_device *pdev)
 	if (IS_ERR(pci->dbi_base))
 		return PTR_ERR(pci->dbi_base);
 
+	pcie->big_endian = of_property_read_bool(dev->of_node, "big-endian");
+
+	if (pcie->drvdata->lut_off)
+		pcie->lut_base = pci->dbi_base + pcie->drvdata->lut_off;
+
+	if (pcie->drvdata->pf_off)
+		pcie->pf_base = pci->dbi_base + pcie->drvdata->pf_off;
+
 	if (!ls_pcie_is_bridge(pcie))
 		return -ENODEV;
 
@@ -150,12 +449,91 @@ static int ls_pcie_probe(struct platform_device *pdev)
 	return dw_pcie_host_init(&pci->pp);
 }
 
+static bool ls_pcie_pm_check(struct ls_pcie *pcie)
+{
+	if (!pcie->ep_presence) {
+		dev_dbg(pcie->pci->dev, "Endpoint isn't present\n");
+		return false;
+	}
+
+	if (!pcie->pm_support)
+		return false;
+
+	return true;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int ls_pcie_suspend_noirq(struct device *dev)
+{
+	struct ls_pcie *pcie = dev_get_drvdata(dev);
+	struct dw_pcie *pci = pcie->pci;
+	u32 val;
+	int ret;
+
+	if (!ls_pcie_pm_check(pcie))
+		return 0;
+
+	pcie->drvdata->pm_ops->send_turn_off_message(pcie);
+
+	/* 10ms timeout to check L2 ready */
+	ret = readl_poll_timeout(pci->dbi_base + PCIE_PORT_DEBUG0,
+				 val, LS_PCIE_IS_L2(val), 100, 10000);
+	if (ret) {
+		dev_err(dev, "PCIe link enter L2 timeout! ltssm = 0x%x\n", val);
+		return ret;
+	}
+
+	ls_pcie_set_dstate(pcie, 0x3);
+
+	return 0;
+}
+
+static int ls_pcie_resume_noirq(struct device *dev)
+{
+	struct ls_pcie *pcie = dev_get_drvdata(dev);
+	struct dw_pcie *pci = pcie->pci;
+	int ret;
+
+	if (!ls_pcie_pm_check(pcie))
+		return 0;
+
+	ls_pcie_set_dstate(pcie, 0x0);
+
+	pcie->drvdata->pm_ops->exit_from_l2(pcie);
+
+	dw_pcie_setup_rc(&pci->pp);
+
+	/* delay 10 ms to access EP */
+	mdelay(10);
+
+	ret = ls_pcie_host_init(&pci->pp);
+	if (ret) {
+		dev_err(dev, "ls_pcie_host_init failed! ret = 0x%x\n", ret);
+		return ret;
+	}
+
+	ret = dw_pcie_wait_for_link(pci);
+	if (ret) {
+		dev_err(dev, "wait link up timeout! ret = 0x%x\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops ls_pcie_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(ls_pcie_suspend_noirq,
+				      ls_pcie_resume_noirq)
+};
+
 static struct platform_driver ls_pcie_driver = {
 	.probe = ls_pcie_probe,
 	.driver = {
 		.name = "layerscape-pcie",
 		.of_match_table = ls_pcie_of_match,
 		.suppress_bind_attrs = true,
+		.pm = &ls_pcie_pm_ops,
 	},
 };
 builtin_platform_driver(ls_pcie_driver);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 7247c8b01f04..067b48a07100 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -54,6 +54,7 @@
 #define PCIE_PORT_DEBUG0		0x728
 #define PORT_LOGIC_LTSSM_STATE_MASK	0x1f
 #define PORT_LOGIC_LTSSM_STATE_L0	0x11
+#define PORT_LOGIC_LTSSM_STATE_L2	0x15
 #define PCIE_PORT_DEBUG1		0x72C
 #define PCIE_PORT_DEBUG1_LINK_UP		BIT(4)
 #define PCIE_PORT_DEBUG1_LINK_IN_TRAINING	BIT(29)
-- 
2.17.1

Re: [PATCHv5 6/6] PCI: layerscape: Add power management support

[Rob Herring]

On Tue, Apr 6, 2021 at 10:04 PM Zhiqiang Hou <Zhiqiang.Hou@nxp.com> wrote:
>
> From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
>
> Add PME_Turn_Off/PME_TO_Ack handshake sequence, and finally
> put the PCIe controller into D3 state after the L2/L3 ready
> state transition process completion.
>
> Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
> ---
> V5:
>  - Fix a typo of the parameter given to function dw_pcie_setup_rc()
>
>  drivers/pci/controller/dwc/pci-layerscape.c  | 382 ++++++++++++++++++-
>  drivers/pci/controller/dwc/pcie-designware.h |   1 +
>  2 files changed, 381 insertions(+), 2 deletions(-)

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCHv5 6/6] PCI: layerscape: Add power management support

[Krzysztof Wilczyński]

Hi,

[...]
> +/* PF Message Command Register */
> +#define LS_PCIE_PF_MCR		0x2c
> +#define PF_MCR_PTOMR		BIT(0)
> +#define PF_MCR_EXL2S		BIT(1)
> +
> +/* LS1021A PEXn PM Write Control Register */
> +#define SCFG_PEXPMWRCR(idx)	(0x5c + (idx) * 0x64)
> +#define PMXMTTURNOFF		BIT(31)
> +#define SCFG_PEXSFTRSTCR	0x190
> +#define PEXSR(idx)		BIT(idx)
> +
> +/* LS1043A PEX PME control register */
> +#define SCFG_PEXPMECR		0x144
> +#define PEXPME(idx)		BIT(31 - (idx) * 4)
> +
> +/* LS1043A PEX LUT debug register */
> +#define LS_PCIE_LDBG	0x7fc
> +#define LDBG_SR		BIT(30)
> +#define LDBG_WE		BIT(31)

A small nitpick: a consistent capitalisation of "control" and "debug", and
"register" in the comments above.

[...]
> +static void ls_pcie_lut_writel(struct ls_pcie *pcie, u32 off, u32 val)
> +{
> +	if (pcie->big_endian)
> +		return iowrite32be(val, pcie->lut_base + off);
> +
> +	return iowrite32(val, pcie->lut_base + off);
> +
> +}

Surplus newline above after the return statement.

[...]
> +static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val)
> +{
> +	if (pcie->big_endian)
> +		return iowrite32be(val, pcie->pf_base + off);
> +
> +	return iowrite32(val, pcie->pf_base + off);
> +
> +}

Surplus newline above after the return statement.

[...]
> +static void ls_pcie_send_turnoff_msg(struct ls_pcie *pcie)
> +{
> +	u32 val;
> +	int ret;
> +
> +	val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
> +	val |= PF_MCR_PTOMR;
> +	ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
> +
> +	ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
> +				 val, !(val & PF_MCR_PTOMR), 100, 10000);
> +	if (ret)
> +		dev_info(pcie->pci->dev, "poll turn off message timeout\n");
> +}

Would this dev_info() be more of a warning or an error?  A timeout is
potentially a problem, correct?

[...]
> +static void ls1021a_pcie_send_turnoff_msg(struct ls_pcie *pcie)
> +{
> +	u32 val;
> +
> +	if (!pcie->scfg) {
> +		dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
> +		return;
> +	}
> +
> +	/* Send Turn_off message */
> +	regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
> +	val |= PMXMTTURNOFF;
> +	regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
> +
> +	mdelay(10);

We often, customary, document why a particular mdelay() is needed.  You
also did this in other part of the code, so perhaps adding a note here (and
everywhere else) would be nice for keeping the consistency.

[...]
> +static void ls_pcie_exit_from_l2(struct ls_pcie *pcie)
> +{
> +	u32 val;
> +	int ret;
> +
> +	val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
> +	val |= PF_MCR_EXL2S;
> +	ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
> +
> +	ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
> +				 val, !(val & PF_MCR_EXL2S), 100, 10000);
> +	if (ret)
> +		dev_info(pcie->pci->dev, "poll exit L2 state timeout\n");
> +}

Similarly to the question above: is this timeout something more severe and
would warrant a warning or an error here instead?

[...]
> +static void ls1021a_pcie_exit_from_l2(struct ls_pcie *pcie)
> +{
> +	u32 val;
> +
> +	regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
> +	val |= PEXSR(pcie->index);
> +	regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
> +
> +	regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
> +	val &= ~PEXSR(pcie->index);
> +	regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
> +
> +	mdelay(1);

Aside of documenting this mdelay() here, if possible, would 1 be enough?
Everywhere else you seem to use 10 consistently.

> +
> +	ls_pcie_retrain_link(pcie);
> +}
> +static void ls1043a_pcie_exit_from_l2(struct ls_pcie *pcie)

Missing newline above to separate code blocks.

> +{
> +	u32 val;
> +
> +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> +	val |= LDBG_WE;
> +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> +	val |= LDBG_SR;
> +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> +	val &= ~LDBG_SR;
> +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> +	val &= ~LDBG_WE;
> +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	mdelay(1);

See comment above.

[...]
> +static int ls1021a_pcie_pm_init(struct ls_pcie *pcie)
> +{
> +	struct device *dev = pcie->pci->dev;
> +	u32 index[2];
> +	int ret;
> +
> +	pcie->scfg = syscon_regmap_lookup_by_phandle(dev->of_node,
> +						     "fsl,pcie-scfg");
> +	if (IS_ERR(pcie->scfg)) {
> +		ret = PTR_ERR(pcie->scfg);
> +		dev_err(dev, "No syscfg phandle specified\n");
> +		pcie->scfg = NULL;
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
> +					 index, 2);
> +	if (ret) {
> +		pcie->scfg = NULL;
> +		return ret;
> +	}
> +
> +	pcie->index = index[1];
> +
> +	return 0;
> +}

Just an idea: what about using goto for error handling?

(...)
	if (IS_ERR(pcie->scfg)) {
		ret = PTR_ERR(pcie->scfg);
		dev_err(dev, "No syscfg phandle specified\n");
		goto error;
	}

	ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
					 index, 2);
	if (ret)
		goto error;

	pcie->index = index[1];

	return 0;

error:
	pcie->scfg = NULL;
	return ret;
}

Not necessarily better or worse compared with your version, so it would be
more of a matter of personal preference here.

> +static int ls_pcie_suspend_noirq(struct device *dev)
> +{
> +	struct ls_pcie *pcie = dev_get_drvdata(dev);
> +	struct dw_pcie *pci = pcie->pci;
> +	u32 val;
> +	int ret;
> +
> +	if (!ls_pcie_pm_check(pcie))
> +		return 0;
> +
> +	pcie->drvdata->pm_ops->send_turn_off_message(pcie);
> +
> +	/* 10ms timeout to check L2 ready */
> +	ret = readl_poll_timeout(pci->dbi_base + PCIE_PORT_DEBUG0,
> +				 val, LS_PCIE_IS_L2(val), 100, 10000);
> +	if (ret) {
> +		dev_err(dev, "PCIe link enter L2 timeout! ltssm = 0x%x\n", val);
> +		return ret;
> +	}

The error message above could be improve to be more like an error stating
that something failed and such, as currently it looks like a debug message,
unless it was intended as such.

[...]
> +static int ls_pcie_resume_noirq(struct device *dev)
> +{
> +	struct ls_pcie *pcie = dev_get_drvdata(dev);
> +	struct dw_pcie *pci = pcie->pci;
> +	int ret;
> +
> +	if (!ls_pcie_pm_check(pcie))
> +		return 0;
> +
> +	ls_pcie_set_dstate(pcie, 0x0);
> +
> +	pcie->drvdata->pm_ops->exit_from_l2(pcie);
> +
> +	dw_pcie_setup_rc(&pci->pp);
> +
> +	/* delay 10 ms to access EP */
> +	mdelay(10);
> +
> +	ret = ls_pcie_host_init(&pci->pp);
> +	if (ret) {
> +		dev_err(dev, "ls_pcie_host_init failed! ret = 0x%x\n", ret);
> +		return ret;
> +	}

A small nitpick: error messages that are directed at end users should have
a little more context than just the function name.

	Krzysztof

RE: [PATCHv5 6/6] PCI: layerscape: Add power management support

[Z.Q. Hou]

Hi Krzysztof,

Thanks a lot for your comments!

> -----Original Message-----
> From: Krzysztof Wilczyński [mailto:kw@linux.com]
> Sent: 2021年11月12日 8:37
> To: Z.Q. Hou <zhiqiang.hou@nxp.com>
> Cc: linux-pci@vger.kernel.org; devicetree@vger.kernel.org;
> linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> lorenzo.pieralisi@arm.com; robh+dt@kernel.org; bhelgaas@google.com;
> shawnguo@kernel.org; Leo Li <leoyang.li@nxp.com>;
> gustavo.pimentel@synopsys.com; M.H. Lian <minghuan.lian@nxp.com>;
> Mingkai Hu <mingkai.hu@nxp.com>; Roy Zang <roy.zang@nxp.com>
> Subject: Re: [PATCHv5 6/6] PCI: layerscape: Add power management support
> 
> Hi,
> 
> [...]
> > +/* PF Message Command Register */
> > +#define LS_PCIE_PF_MCR		0x2c
> > +#define PF_MCR_PTOMR		BIT(0)
> > +#define PF_MCR_EXL2S		BIT(1)
> > +
> > +/* LS1021A PEXn PM Write Control Register */
> > +#define SCFG_PEXPMWRCR(idx)	(0x5c + (idx) * 0x64)
> > +#define PMXMTTURNOFF		BIT(31)
> > +#define SCFG_PEXSFTRSTCR	0x190
> > +#define PEXSR(idx)		BIT(idx)
> > +
> > +/* LS1043A PEX PME control register */
> > +#define SCFG_PEXPMECR		0x144
> > +#define PEXPME(idx)		BIT(31 - (idx) * 4)
> > +
> > +/* LS1043A PEX LUT debug register */
> > +#define LS_PCIE_LDBG	0x7fc
> > +#define LDBG_SR		BIT(30)
> > +#define LDBG_WE		BIT(31)
> 
> A small nitpick: a consistent capitalisation of "control" and "debug", and
> "register" in the comments above.

Good suggestion, will make them consistent next version.

> 
> [...]
> > +static void ls_pcie_lut_writel(struct ls_pcie *pcie, u32 off, u32
> > +val) {
> > +	if (pcie->big_endian)
> > +		return iowrite32be(val, pcie->lut_base + off);
> > +
> > +	return iowrite32(val, pcie->lut_base + off);
> > +
> > +}
> 
> Surplus newline above after the return statement.
> 
> [...]
> > +static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val)
> > +{
> > +	if (pcie->big_endian)
> > +		return iowrite32be(val, pcie->pf_base + off);
> > +
> > +	return iowrite32(val, pcie->pf_base + off);
> > +
> > +}
> 
> Surplus newline above after the return statement.
> 

Will remove these lines next version.

> [...]
> > +static void ls_pcie_send_turnoff_msg(struct ls_pcie *pcie) {
> > +	u32 val;
> > +	int ret;
> > +
> > +	val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
> > +	val |= PF_MCR_PTOMR;
> > +	ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
> > +
> > +	ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
> > +				 val, !(val & PF_MCR_PTOMR), 100, 10000);
> > +	if (ret)
> > +		dev_info(pcie->pci->dev, "poll turn off message timeout\n"); }
> 
> Would this dev_info() be more of a warning or an error?  A timeout is
> potentially a problem, correct?
>

An error message is better here, will change next version.
 
> [...]
> > +static void ls1021a_pcie_send_turnoff_msg(struct ls_pcie *pcie) {
> > +	u32 val;
> > +
> > +	if (!pcie->scfg) {
> > +		dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
> > +		return;
> > +	}
> > +
> > +	/* Send Turn_off message */
> > +	regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
> > +	val |= PMXMTTURNOFF;
> > +	regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
> > +
> > +	mdelay(10);
> 
> We often, customary, document why a particular mdelay() is needed.  You also
> did this in other part of the code, so perhaps adding a note here (and
> everywhere else) would be nice for keeping the consistency.
> 

Will add next version.

> [...]
> > +static void ls_pcie_exit_from_l2(struct ls_pcie *pcie) {
> > +	u32 val;
> > +	int ret;
> > +
> > +	val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
> > +	val |= PF_MCR_EXL2S;
> > +	ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
> > +
> > +	ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
> > +				 val, !(val & PF_MCR_EXL2S), 100, 10000);
> > +	if (ret)
> > +		dev_info(pcie->pci->dev, "poll exit L2 state timeout\n"); }
> 
> Similarly to the question above: is this timeout something more severe and
> would warrant a warning or an error here instead?
> 

Agree.

> [...]
> > +static void ls1021a_pcie_exit_from_l2(struct ls_pcie *pcie) {
> > +	u32 val;
> > +
> > +	regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
> > +	val |= PEXSR(pcie->index);
> > +	regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
> > +
> > +	regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
> > +	val &= ~PEXSR(pcie->index);
> > +	regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
> > +
> > +	mdelay(1);
> 
> Aside of documenting this mdelay() here, if possible, would 1 be enough?
> Everywhere else you seem to use 10 consistently.
> 

It's enough and didn't encounter a fail in thousands regressions.

> > +
> > +	ls_pcie_retrain_link(pcie);
> > +}
> > +static void ls1043a_pcie_exit_from_l2(struct ls_pcie *pcie)
> 
> Missing newline above to separate code blocks.
> 

Will add next version.

> > +{
> > +	u32 val;
> > +
> > +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> > +	val |= LDBG_WE;
> > +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> > +
> > +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> > +	val |= LDBG_SR;
> > +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> > +
> > +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> > +	val &= ~LDBG_SR;
> > +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> > +
> > +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> > +	val &= ~LDBG_WE;
> > +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> > +
> > +	mdelay(1);
> 
> See comment above.
> 
> [...]
> > +static int ls1021a_pcie_pm_init(struct ls_pcie *pcie) {
> > +	struct device *dev = pcie->pci->dev;
> > +	u32 index[2];
> > +	int ret;
> > +
> > +	pcie->scfg = syscon_regmap_lookup_by_phandle(dev->of_node,
> > +						     "fsl,pcie-scfg");
> > +	if (IS_ERR(pcie->scfg)) {
> > +		ret = PTR_ERR(pcie->scfg);
> > +		dev_err(dev, "No syscfg phandle specified\n");
> > +		pcie->scfg = NULL;
> > +		return ret;
> > +	}
> > +
> > +	ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
> > +					 index, 2);
> > +	if (ret) {
> > +		pcie->scfg = NULL;
> > +		return ret;
> > +	}
> > +
> > +	pcie->index = index[1];
> > +
> > +	return 0;
> > +}
> 
> Just an idea: what about using goto for error handling?
> 
> (...)
> 	if (IS_ERR(pcie->scfg)) {
> 		ret = PTR_ERR(pcie->scfg);
> 		dev_err(dev, "No syscfg phandle specified\n");
> 		goto error;
> 	}
> 
> 	ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
> 					 index, 2);
> 	if (ret)
> 		goto error;
> 
> 	pcie->index = index[1];
> 
> 	return 0;
> 
> error:
> 	pcie->scfg = NULL;
> 	return ret;
> }
> 
> Not necessarily better or worse compared with your version, so it would be
> more of a matter of personal preference here.

Thanks for the good suggestion!

> 
> > +static int ls_pcie_suspend_noirq(struct device *dev) {
> > +	struct ls_pcie *pcie = dev_get_drvdata(dev);
> > +	struct dw_pcie *pci = pcie->pci;
> > +	u32 val;
> > +	int ret;
> > +
> > +	if (!ls_pcie_pm_check(pcie))
> > +		return 0;
> > +
> > +	pcie->drvdata->pm_ops->send_turn_off_message(pcie);
> > +
> > +	/* 10ms timeout to check L2 ready */
> > +	ret = readl_poll_timeout(pci->dbi_base + PCIE_PORT_DEBUG0,
> > +				 val, LS_PCIE_IS_L2(val), 100, 10000);
> > +	if (ret) {
> > +		dev_err(dev, "PCIe link enter L2 timeout! ltssm = 0x%x\n", val);
> > +		return ret;
> > +	}
> 
> The error message above could be improve to be more like an error stating that
> something failed and such, as currently it looks like a debug message, unless it
> was intended as such.

Exactly, will improve.

> 
> [...]
> > +static int ls_pcie_resume_noirq(struct device *dev) {
> > +	struct ls_pcie *pcie = dev_get_drvdata(dev);
> > +	struct dw_pcie *pci = pcie->pci;
> > +	int ret;
> > +
> > +	if (!ls_pcie_pm_check(pcie))
> > +		return 0;
> > +
> > +	ls_pcie_set_dstate(pcie, 0x0);
> > +
> > +	pcie->drvdata->pm_ops->exit_from_l2(pcie);
> > +
> > +	dw_pcie_setup_rc(&pci->pp);
> > +
> > +	/* delay 10 ms to access EP */
> > +	mdelay(10);
> > +
> > +	ret = ls_pcie_host_init(&pci->pp);
> > +	if (ret) {
> > +		dev_err(dev, "ls_pcie_host_init failed! ret = 0x%x\n", ret);
> > +		return ret;
> > +	}
> 
> A small nitpick: error messages that are directed at end users should have a little
> more context than just the function name.

Will remove the return value check, currently this func always succeed.

Thanks,
Zhiqiang

> 
> 	Krzysztof

Re: [PATCHv5 0/6] PCI: layerscape: Add power management support

[Li Yang]

On Wed, Apr 7, 2021 at 9:13 AM Zhiqiang Hou <Zhiqiang.Hou@nxp.com> wrote:
>
> From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
>
> This patch series is to add PCIe power management support for NXP
> Layerscape platforms.
>
> Hou Zhiqiang (6):
>   PCI: layerscape: Change to use the DWC common link-up check function
>   dt-bindings: pci: layerscape-pci: Add a optional property big-endian
>   arm64: dts: layerscape: Add big-endian property for PCIe nodes
>   dt-bindings: pci: layerscape-pci: Update the description of SCFG
>     property
>   arm64: dts: ls1043a: Add SCFG phandle for PCIe nodes
>   PCI: layerscape: Add power management support
>
>  .../bindings/pci/layerscape-pci.txt           |   6 +-
>  .../arm64/boot/dts/freescale/fsl-ls1012a.dtsi |   1 +
>  .../arm64/boot/dts/freescale/fsl-ls1043a.dtsi |   6 +
>  .../arm64/boot/dts/freescale/fsl-ls1046a.dtsi |   3 +
>  drivers/pci/controller/dwc/pci-layerscape.c   | 450 ++++++++++++++----
>  drivers/pci/controller/dwc/pcie-designware.h  |   1 +
>  6 files changed, 370 insertions(+), 97 deletions(-)

Hi Bjorn,

I don't see any feedback on this version.  Is there any chance that
the binding/driver changes can be picked up?

Regards,
Leo

Re: [PATCHv5 0/6] PCI: layerscape: Add power management support

[Bjorn Helgaas]

On Thu, Nov 11, 2021 at 03:21:37PM -0600, Li Yang wrote:
> On Wed, Apr 7, 2021 at 9:13 AM Zhiqiang Hou <Zhiqiang.Hou@nxp.com> wrote:
> >
> > From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
> >
> > This patch series is to add PCIe power management support for NXP
> > Layerscape platforms.
> >
> > Hou Zhiqiang (6):
> >   PCI: layerscape: Change to use the DWC common link-up check function
> >   dt-bindings: pci: layerscape-pci: Add a optional property big-endian
> >   arm64: dts: layerscape: Add big-endian property for PCIe nodes
> >   dt-bindings: pci: layerscape-pci: Update the description of SCFG
> >     property
> >   arm64: dts: ls1043a: Add SCFG phandle for PCIe nodes
> >   PCI: layerscape: Add power management support
> >
> >  .../bindings/pci/layerscape-pci.txt           |   6 +-
> >  .../arm64/boot/dts/freescale/fsl-ls1012a.dtsi |   1 +
> >  .../arm64/boot/dts/freescale/fsl-ls1043a.dtsi |   6 +
> >  .../arm64/boot/dts/freescale/fsl-ls1046a.dtsi |   3 +
> >  drivers/pci/controller/dwc/pci-layerscape.c   | 450 ++++++++++++++----
> >  drivers/pci/controller/dwc/pcie-designware.h  |   1 +
> >  6 files changed, 370 insertions(+), 97 deletions(-)
> 
> Hi Bjorn,
> 
> I don't see any feedback on this version.  Is there any chance that
> the binding/driver changes can be picked up?

Probably slipped through the cracks.  We're in the middle of the v5.16
merge window right now.  After v5.16-rc1 is tagged (probably Nov 14),
rebase your series on top of that, incorporate Rob's reviewed-by, and
repost it.  Then Lorenzo will see it and take a look.

Bjorn

RE: [PATCHv5 0/6] PCI: layerscape: Add power management support

[Leo Li]

> -----Original Message-----
> From: Bjorn Helgaas <helgaas@kernel.org>
> Sent: Thursday, November 11, 2021 3:45 PM
> To: Leo Li <leoyang.li@nxp.com>
> Cc: Z.Q. Hou <zhiqiang.hou@nxp.com>; linux-pci@vger.kernel.org; open
> list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS
> <devicetree@vger.kernel.org>; lkml <linux-kernel@vger.kernel.org>;
> moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE <linux-arm-
> kernel@lists.infradead.org>; Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>;
> Rob Herring <robh+dt@kernel.org>; Bjorn Helgaas <bhelgaas@google.com>;
> Shawn Guo <shawnguo@kernel.org>; gustavo.pimentel@synopsys.com;
> M.H. Lian <minghuan.lian@nxp.com>; Mingkai Hu <mingkai.hu@nxp.com>;
> Roy Zang <roy.zang@nxp.com>
> Subject: Re: [PATCHv5 0/6] PCI: layerscape: Add power management support
> 
> On Thu, Nov 11, 2021 at 03:21:37PM -0600, Li Yang wrote:
> > On Wed, Apr 7, 2021 at 9:13 AM Zhiqiang Hou <Zhiqiang.Hou@nxp.com>
> wrote:
> > >
> > > From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
> > >
> > > This patch series is to add PCIe power management support for NXP
> > > Layerscape platforms.
> > >
> > > Hou Zhiqiang (6):
> > >   PCI: layerscape: Change to use the DWC common link-up check function
> > >   dt-bindings: pci: layerscape-pci: Add a optional property big-endian
> > >   arm64: dts: layerscape: Add big-endian property for PCIe nodes
> > >   dt-bindings: pci: layerscape-pci: Update the description of SCFG
> > >     property
> > >   arm64: dts: ls1043a: Add SCFG phandle for PCIe nodes
> > >   PCI: layerscape: Add power management support
> > >
> > >  .../bindings/pci/layerscape-pci.txt           |   6 +-
> > >  .../arm64/boot/dts/freescale/fsl-ls1012a.dtsi |   1 +
> > >  .../arm64/boot/dts/freescale/fsl-ls1043a.dtsi |   6 +
> > >  .../arm64/boot/dts/freescale/fsl-ls1046a.dtsi |   3 +
> > >  drivers/pci/controller/dwc/pci-layerscape.c   | 450 ++++++++++++++----
> > >  drivers/pci/controller/dwc/pcie-designware.h  |   1 +
> > >  6 files changed, 370 insertions(+), 97 deletions(-)
> >
> > Hi Bjorn,
> >
> > I don't see any feedback on this version.  Is there any chance that
> > the binding/driver changes can be picked up?
> 
> Probably slipped through the cracks.  We're in the middle of the v5.16 merge
> window right now.  After v5.16-rc1 is tagged (probably Nov 14), rebase your
> series on top of that, incorporate Rob's reviewed-by, and repost it.  Then
> Lorenzo will see it and take a look.

Thanks Bjorn,

While we waiting for the repost and review for the driver change, the dt-binding
updates seems to be unrelated to the driver changes.  So probably they can be
applied separately to make the dts changes mergeable?

Regards,
Leo