diff mbox series

[2/7] PCI: layerscape: Change to use the DWC common link-up check function

Message ID 20200907053801.22149-3-Zhiqiang.Hou@nxp.com (mailing list archive)
State Superseded, archived
Delegated to: Lorenzo Pieralisi
Headers show
Series PCI: layerscape: Add power management support | expand

Commit Message

Z.Q. Hou Sept. 7, 2020, 5:37 a.m. UTC 
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>
---
 drivers/pci/controller/dwc/pci-layerscape.c | 141 ++------------------
 1 file changed, 10 insertions(+), 131 deletions(-)

Comments

Rob Herring (Arm) Sept. 15, 2020, 1:19 a.m. UTC | #1 
On Mon, Sep 07, 2020 at 01:37:56PM +0800, Zhiqiang Hou wrote:
> 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>
> ---
>  drivers/pci/controller/dwc/pci-layerscape.c | 141 ++------------------
>  1 file changed, 10 insertions(+), 131 deletions(-)

IIRC, the common function uses a debug register. I've been wondering do 
the common PCIe config space registers not work on DWC? If you have an 
answer, that would be great for some potential additional cleanups.

Either way,

Reviewed-by: Rob Herring <robh@kernel.org>
Z.Q. Hou Sept. 15, 2020, 6:22 a.m. UTC | #2 
Hi Rob,

Thanks a lot for your review!

> -----Original Message-----
> From: Rob Herring <robh@kernel.org>
> Sent: 2020年9月15日 9:20
> To: Z.q. Hou <zhiqiang.hou@nxp.com>
> Cc: linux-pci@vger.kernel.org; devicetree@vger.kernel.org;
> linux-kernel@vger.kernel.org; bhelgaas@google.com;
> shawnguo@kernel.org; Leo Li <leoyang.li@nxp.com>;
> lorenzo.pieralisi@arm.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: [PATCH 2/7] PCI: layerscape: Change to use the DWC common
> link-up check function
> 
> On Mon, Sep 07, 2020 at 01:37:56PM +0800, Zhiqiang Hou wrote:
> > 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>
> > ---
> >  drivers/pci/controller/dwc/pci-layerscape.c | 141
> > ++------------------
> >  1 file changed, 10 insertions(+), 131 deletions(-)
> 
> IIRC, the common function uses a debug register. I've been wondering do
> the common PCIe config space registers not work on DWC? If you have an
> answer, that would be great for some potential additional cleanups.
> 

You're right it uses a port debug register, but I'm not sure if the Link status
Register of common PCIe config space works or not on DWC.

Gustavo, can you help answer this query?

Regards,
Zhiqiang

> Either way,
> 
> Reviewed-by: Rob Herring <robh@kernel.org>
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
index f24f79a70d9a..be404c16bcbe 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)
@@ -91,38 +78,6 @@  static void ls_pcie_disable_outbound_atus(struct ls_pcie *pcie)
 		dw_pcie_disable_atu(pcie->pci, i, DW_PCIE_REGION_OUTBOUND);
 }
 
-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)
 {
@@ -155,33 +110,6 @@  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 int ls_pcie_msi_host_init(struct pcie_port *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -205,71 +133,25 @@  static int ls_pcie_msi_host_init(struct pcie_port *pp)
 	return 0;
 }
 
-static const struct dw_pcie_host_ops ls1021_pcie_host_ops = {
-	.host_init = ls1021_pcie_host_init,
-	.msi_host_init = ls_pcie_msi_host_init,
-};
-
 static const struct dw_pcie_host_ops ls_pcie_host_ops = {
 	.host_init = ls_pcie_host_init,
 	.msi_host_init = ls_pcie_msi_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,
-	.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,
+static const struct ls_pcie_drvdata layerscape_drvdata = {
 	.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 },
 	{ },
 };
 
@@ -310,7 +192,6 @@  static int __init 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;
 
 	pcie->pci = pci;
 
@@ -319,8 +200,6 @@  static int __init 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;