[v2,6/8] PCI: al: Add support for DW based driver type
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Message ID 20190718094718.25083-2-jonnyc@amazon.com
State Superseded
Headers show
Series
  • Amazon's Annapurna Labs DT-based PCIe host controller driver
Related show

Commit Message

Chocron, Jonathan July 18, 2019, 9:47 a.m. UTC
This driver is DT based and utilizes the DesignWare APIs.
It allows using a smaller ECAM range for a larger bus range -
usually an entire bus uses 1MB of address space, but the driver
can use it for a larger number of buses.

All link initializations are handled by the boot FW.

Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
---
 drivers/pci/controller/dwc/Kconfig   |  12 +
 drivers/pci/controller/dwc/pcie-al.c | 373 +++++++++++++++++++++++++++
 2 files changed, 385 insertions(+)

Comments

Gustavo Pimentel July 19, 2019, 8:55 a.m. UTC | #1
On Thu, Jul 18, 2019 at 10:47:16, Jonathan Chocron <jonnyc@amazon.com> 
wrote:

> This driver is DT based and utilizes the DesignWare APIs.
> It allows using a smaller ECAM range for a larger bus range -
> usually an entire bus uses 1MB of address space, but the driver
> can use it for a larger number of buses.
> 
> All link initializations are handled by the boot FW.
> 
> Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
> ---
>  drivers/pci/controller/dwc/Kconfig   |  12 +
>  drivers/pci/controller/dwc/pcie-al.c | 373 +++++++++++++++++++++++++++
>  2 files changed, 385 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index 6ea778ae4877..3c6094cbcc3b 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -230,4 +230,16 @@ config PCIE_UNIPHIER
>  	  Say Y here if you want PCIe controller support on UniPhier SoCs.
>  	  This driver supports LD20 and PXs3 SoCs.
>  
> +config PCIE_AL
> +	bool "Amazon Annapurna Labs PCIe controller"
> +	depends on OF && (ARM64 || COMPILE_TEST)
> +	depends on PCI_MSI_IRQ_DOMAIN
> +	select PCIE_DW_HOST
> +	help
> +	  Say Y here to enable support of the Amazon's Annapurna Labs PCIe
> +	  controller IP on Amazon SoCs. The PCIe controller uses the DesignWare
> +	  core plus Annapurna Labs proprietary hardware wrappers. This is
> +	  required only for DT-based platforms. ACPI platforms with the
> +	  Annapurna Labs PCIe controller don't need to enable this.
> +
>  endmenu
> diff --git a/drivers/pci/controller/dwc/pcie-al.c b/drivers/pci/controller/dwc/pcie-al.c
> index 3ab58f0584a8..40555532fb9a 100644
> --- a/drivers/pci/controller/dwc/pcie-al.c
> +++ b/drivers/pci/controller/dwc/pcie-al.c
> @@ -91,3 +91,376 @@ struct pci_ecam_ops al_pcie_ops = {
>  };
>  
>  #endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */
> +
> +#ifdef CONFIG_PCIE_AL
> +
> +#include <linux/of_pci.h>
> +#include "pcie-designware.h"
> +
> +#define AL_PCIE_REV_ID_2	2
> +#define AL_PCIE_REV_ID_3	3
> +#define AL_PCIE_REV_ID_4	4
> +
> +#define AXI_BASE_OFFSET		0x0
> +
> +#define DEVICE_ID_OFFSET	0x16c
> +
> +#define DEVICE_REV_ID			0x0
> +#define DEVICE_REV_ID_DEV_ID_MASK	GENMASK(31, 16)
> +
> +#define DEVICE_REV_ID_DEV_ID_X4		0
> +#define DEVICE_REV_ID_DEV_ID_X8		2
> +#define DEVICE_REV_ID_DEV_ID_X16	4
> +
> +#define OB_CTRL_REV1_2_OFFSET	0x0040
> +#define OB_CTRL_REV3_5_OFFSET	0x0030
> +
> +#define CFG_TARGET_BUS			0x0
> +#define CFG_TARGET_BUS_MASK_MASK	GENMASK(7, 0)
> +#define CFG_TARGET_BUS_BUSNUM_MASK	GENMASK(15, 8)
> +
> +#define CFG_CONTROL			0x4
> +#define CFG_CONTROL_SUBBUS_MASK		GENMASK(15, 8)
> +#define CFG_CONTROL_SEC_BUS_MASK	GENMASK(23, 16)
> +
> +struct al_pcie_reg_offsets {
> +	unsigned int ob_ctrl;
> +};
> +
> +struct al_pcie_target_bus_cfg {
> +	u8 reg_val;
> +	u8 reg_mask;
> +	u8 ecam_mask;
> +};
> +
> +struct al_pcie {
> +	struct dw_pcie *pci;
> +	void __iomem *controller_base; /* base of PCIe unit (not DW core) */
> +	struct device *dev;
> +	resource_size_t ecam_size;
> +	unsigned int controller_rev_id;
> +	struct al_pcie_reg_offsets reg_offsets;
> +	struct al_pcie_target_bus_cfg target_bus_cfg;
> +};
> +
> +#define PCIE_ECAM_DEVFN(x)		(((x) & 0xff) << 12)
> +
> +#define to_al_pcie(x)		dev_get_drvdata((x)->dev)
> +
> +static int al_pcie_rev_id_get(struct al_pcie *pcie, unsigned int *rev_id)
> +{
> +	void __iomem *dev_rev_id_addr;
> +	u32 dev_rev_id;
> +
> +	dev_rev_id_addr = (void __iomem *)((uintptr_t)pcie->controller_base +
> +			  AXI_BASE_OFFSET + DEVICE_ID_OFFSET + DEVICE_REV_ID);
> +
> +	dev_rev_id = FIELD_GET(DEVICE_REV_ID_DEV_ID_MASK,
> +			       readl(dev_rev_id_addr));
> +	switch (dev_rev_id) {
> +	case DEVICE_REV_ID_DEV_ID_X4:
> +		*rev_id = AL_PCIE_REV_ID_2;
> +		break;
> +	case DEVICE_REV_ID_DEV_ID_X8:
> +		*rev_id = AL_PCIE_REV_ID_3;
> +		break;
> +	case DEVICE_REV_ID_DEV_ID_X16:
> +		*rev_id = AL_PCIE_REV_ID_4;
> +		break;
> +	default:
> +		dev_err(pcie->dev, "Unsupported dev_rev_id (0x%x)\n",
> +			dev_rev_id);
> +		return -EINVAL;
> +	}
> +
> +	dev_dbg(pcie->dev, "dev_rev_id: 0x%x\n", dev_rev_id);

Consider s/dev_dbg/pci_dbg/g

> +
> +	return 0;
> +}
> +
> +static int al_pcie_reg_offsets_set(struct al_pcie *pcie)
> +{
> +	switch (pcie->controller_rev_id) {
> +	case AL_PCIE_REV_ID_2:
> +		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV1_2_OFFSET;
> +		break;
> +	case AL_PCIE_REV_ID_3:
> +	case AL_PCIE_REV_ID_4:
> +		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV3_5_OFFSET;
> +		break;
> +	default:
> +		dev_err(pcie->dev, "Unsupported controller rev_id: 0x%x\n",
> +			pcie->controller_rev_id);

Consider s/dev_err/pci_err/g

> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static inline void al_pcie_target_bus_set(struct al_pcie *pcie,
> +					  u8 target_bus,
> +					  u8 mask_target_bus)
> +{
> +	void __iomem *cfg_control_addr;
> +	u32 reg;
> +
> +	reg = FIELD_PREP(CFG_TARGET_BUS_MASK_MASK, mask_target_bus) |
> +	      FIELD_PREP(CFG_TARGET_BUS_BUSNUM_MASK, target_bus);
> +
> +	cfg_control_addr = (void __iomem *)((uintptr_t)pcie->controller_base +
> +			   AXI_BASE_OFFSET + pcie->reg_offsets.ob_ctrl +
> +			   CFG_TARGET_BUS);
> +
> +	writel(reg, cfg_control_addr);

From what I'm seeing you commonly use writel() and readl() with a common 
base address, such as pcie->controller_base + AXI_BASE_OFFSET.
I'd suggest to creating a writel and readl with that offset built-in.

> +}
> +
> +static void __iomem *al_pcie_conf_addr_map(struct al_pcie *pcie,
> +					   unsigned int busnr,
> +					   unsigned int devfn)
> +{
> +	void __iomem *pci_base_addr;

Consider passing this variable declaration to the bottom, following the 
reverse tree order.

> +	struct pcie_port *pp = &pcie->pci->pp;
> +	struct al_pcie_target_bus_cfg *target_bus_cfg = &pcie->target_bus_cfg;
> +	unsigned int busnr_ecam = busnr & target_bus_cfg->ecam_mask;
> +	unsigned int busnr_reg = busnr & target_bus_cfg->reg_mask;
> +
> +	pci_base_addr = (void __iomem *)((uintptr_t)pp->va_cfg0_base +
> +					 (busnr_ecam << 20) +
> +					 PCIE_ECAM_DEVFN(devfn));
> +
> +	if (busnr_reg != target_bus_cfg->reg_val) {
> +		dev_dbg(pcie->pci->dev, "Changing target bus busnum val from 0x%x to 0x%x\n",
> +			target_bus_cfg->reg_val, busnr_reg);
> +		target_bus_cfg->reg_val = busnr_reg;
> +		al_pcie_target_bus_set(pcie,
> +				       target_bus_cfg->reg_val,
> +				       target_bus_cfg->reg_mask);
> +	}
> +
> +	return pci_base_addr;
> +}
> +
> +static int al_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
> +				 unsigned int devfn, int where, int size,
> +				 u32 *val)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct al_pcie *pcie = to_al_pcie(pci);
> +	unsigned int busnr = bus->number;
> +	void __iomem *pci_addr;
> +	int rc;
> +
> +	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
> +
> +	rc = dw_pcie_read(pci_addr + where, size, val);
> +
> +	dev_dbg(pci->dev, "%d-byte config read from %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
> +		size, pci_domain_nr(bus), bus->number,
> +		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
> +		(pci_addr + where), *val);
> +
> +	return rc;
> +}
> +
> +static int al_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
> +				 unsigned int devfn, int where, int size,
> +				 u32 val)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct al_pcie *pcie = to_al_pcie(pci);
> +	unsigned int busnr = bus->number;
> +	void __iomem *pci_addr;
> +	int rc;
> +
> +	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
> +
> +	rc = dw_pcie_write(pci_addr + where, size, val);
> +
> +	dev_err(pci->dev, "%d-byte config write to %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
> +		size, pci_domain_nr(bus), bus->number,
> +		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
> +		(pci_addr + where), val);
> +
> +	return rc;
> +}
> +
> +static int al_pcie_config_prepare(struct al_pcie *pcie)
> +{
> +	struct al_pcie_target_bus_cfg *target_bus_cfg;
> +	struct pcie_port *pp = &pcie->pci->pp;
> +	unsigned int ecam_bus_mask;
> +	u8 secondary_bus;
> +	u8 subordinate_bus;
> +	void __iomem *cfg_control_addr;
> +	u32 cfg_control;
> +	u32 reg;
> +
> +	target_bus_cfg = &pcie->target_bus_cfg;
> +
> +	ecam_bus_mask = (pcie->ecam_size >> 20) - 1;
> +	if (ecam_bus_mask > 255) {
> +		dev_warn(pcie->dev, "ECAM window size is larger than 256MB. Cutting off at 256\n");
> +		ecam_bus_mask = 255;
> +	}
> +
> +	/* This portion is taken from the transaction address */
> +	target_bus_cfg->ecam_mask = ecam_bus_mask;
> +	/* This portion is taken from the cfg_target_bus reg */
> +	target_bus_cfg->reg_mask = ~target_bus_cfg->ecam_mask;
> +	target_bus_cfg->reg_val = pp->busn->start & target_bus_cfg->reg_mask;
> +
> +	al_pcie_target_bus_set(pcie, target_bus_cfg->reg_val,
> +			       target_bus_cfg->reg_mask);
> +
> +	secondary_bus = pp->busn->start + 1;
> +	subordinate_bus = pp->busn->end;
> +
> +	/* Set the valid values of secondary and subordinate buses */
> +	cfg_control_addr = pcie->controller_base + AXI_BASE_OFFSET +
> +			   pcie->reg_offsets.ob_ctrl + CFG_CONTROL;
> +
> +	cfg_control = readl(cfg_control_addr);
> +
> +	reg = cfg_control &
> +	      ~(CFG_CONTROL_SEC_BUS_MASK | CFG_CONTROL_SUBBUS_MASK);
> +
> +	reg |= FIELD_PREP(CFG_CONTROL_SUBBUS_MASK, subordinate_bus) |
> +	       FIELD_PREP(CFG_CONTROL_SEC_BUS_MASK, secondary_bus);
> +
> +	writel(reg, cfg_control_addr);
> +
> +	return 0;
> +}
> +
> +static int al_pcie_host_init(struct pcie_port *pp)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct al_pcie *pcie = to_al_pcie(pci);
> +	int link_up;
> +	int rc;
> +
> +	link_up = dw_pcie_link_up(pci);
> +	if (!link_up) {
> +		dev_err(pci->dev, "link is not up!\n");
> +		return -ENOLINK;
> +	}
> +
> +	dev_info(pci->dev, "link is up\n");

Consider s/dev_info/pci_info/g

> +
> +	rc = al_pcie_rev_id_get(pcie, &pcie->controller_rev_id);
> +	if (rc)
> +		return rc;
> +
> +	rc = al_pcie_reg_offsets_set(pcie);
> +	if (rc)
> +		return rc;
> +
> +	rc = al_pcie_config_prepare(pcie);
> +	if (rc)
> +		return rc;
> +
> +	return 0;
> +}
> +
> +static const struct dw_pcie_host_ops al_pcie_host_ops = {
> +	.rd_other_conf = al_pcie_rd_other_conf,
> +	.wr_other_conf = al_pcie_wr_other_conf,
> +	.host_init = al_pcie_host_init,
> +};
> +
> +static int al_add_pcie_port(struct pcie_port *pp,
> +			    struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	int ret;
> +
> +	pp->ops = &al_pcie_host_ops;
> +
> +	ret = dw_pcie_host_init(pp);
> +	if (ret) {
> +		dev_err(dev, "failed to initialize host\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct dw_pcie_ops dw_pcie_ops = {
> +};
> +
> +static int al_pcie_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct al_pcie *al_pcie;
> +	struct dw_pcie *pci;
> +	struct resource *dbi_res;
> +	struct resource *controller_res;
> +	struct resource *ecam_res;
> +	int ret;

Please sort the variables following the reverse tree order.

> +
> +	al_pcie = devm_kzalloc(dev, sizeof(*al_pcie), GFP_KERNEL);
> +	if (!al_pcie)
> +		return -ENOMEM;
> +
> +	pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
> +	if (!pci)
> +		return -ENOMEM;
> +
> +	pci->dev = dev;
> +	pci->ops = &dw_pcie_ops;
> +
> +	al_pcie->pci = pci;
> +	al_pcie->dev = dev;
> +
> +	dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
> +	pci->dbi_base = devm_pci_remap_cfg_resource(dev, dbi_res);
> +	if (IS_ERR(pci->dbi_base)) {
> +		dev_err(dev, "couldn't remap dbi base %pR\n", dbi_res);
> +		return PTR_ERR(pci->dbi_base);
> +	}
> +
> +	ecam_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
> +	if (!ecam_res) {
> +		dev_err(dev, "couldn't find 'config' reg in DT\n");
> +		return -ENOENT;
> +	}
> +	al_pcie->ecam_size = resource_size(ecam_res);
> +
> +	controller_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +						      "controller");
> +	al_pcie->controller_base = devm_ioremap_resource(dev, controller_res);
> +	if (IS_ERR(al_pcie->controller_base)) {
> +		dev_err(dev, "couldn't remap controller base %pR\n",
> +			controller_res);
> +		return PTR_ERR(al_pcie->controller_base);
> +	}
> +
> +	dev_dbg(dev, "From DT: dbi_base: %pR, controller_base: %pR\n",
> +		dbi_res, controller_res);
> +
> +	platform_set_drvdata(pdev, al_pcie);
> +
> +	ret = al_add_pcie_port(&pci->pp, pdev);

> +	if (ret)
> +		return ret;
> +
> +	return 0;

Those operations are redundant, aren't they? They can be replaced just 
by:

return ret;

> +}
> +
> +static const struct of_device_id al_pcie_of_match[] = {
> +	{ .compatible = "amazon,al-pcie",
> +	},
> +	{},
> +};
> +
> +static struct platform_driver al_pcie_driver = {
> +	.driver = {
> +		.name	= "al-pcie",
> +		.of_match_table = al_pcie_of_match,
> +		.suppress_bind_attrs = true,
> +	},
> +	.probe = al_pcie_probe,
> +};
> +builtin_platform_driver(al_pcie_driver);
> +
> +#endif /* CONFIG_PCIE_AL*/
> -- 
> 2.17.1
Chocron, Jonathan July 21, 2019, 3:08 p.m. UTC | #2
On Fri, 2019-07-19 at 08:55 +0000, Gustavo Pimentel wrote:
> On Thu, Jul 18, 2019 at 10:47:16, Jonathan Chocron <jonnyc@amazon.com
> > 
> wrote:
> 
> > This driver is DT based and utilizes the DesignWare APIs.
> > It allows using a smaller ECAM range for a larger bus range -
> > usually an entire bus uses 1MB of address space, but the driver
> > can use it for a larger number of buses.
> > 
> > All link initializations are handled by the boot FW.
> > 
> > Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
> > ---
> >  drivers/pci/controller/dwc/Kconfig   |  12 +
> >  drivers/pci/controller/dwc/pcie-al.c | 373
> > +++++++++++++++++++++++++++
> >  2 files changed, 385 insertions(+)
> > 
> > diff --git a/drivers/pci/controller/dwc/Kconfig
> > b/drivers/pci/controller/dwc/Kconfig
> > index 6ea778ae4877..3c6094cbcc3b 100644
> > --- a/drivers/pci/controller/dwc/Kconfig
> > +++ b/drivers/pci/controller/dwc/Kconfig
> > @@ -230,4 +230,16 @@ config PCIE_UNIPHIER
> >  	  Say Y here if you want PCIe controller support on UniPhier
> > SoCs.
> >  	  This driver supports LD20 and PXs3 SoCs.
> >  
> > +config PCIE_AL
> > +	bool "Amazon Annapurna Labs PCIe controller"
> > +	depends on OF && (ARM64 || COMPILE_TEST)
> > +	depends on PCI_MSI_IRQ_DOMAIN
> > +	select PCIE_DW_HOST
> > +	help
> > +	  Say Y here to enable support of the Amazon's Annapurna Labs
> > PCIe
> > +	  controller IP on Amazon SoCs. The PCIe controller uses the
> > DesignWare
> > +	  core plus Annapurna Labs proprietary hardware wrappers. This
> > is
> > +	  required only for DT-based platforms. ACPI platforms with the
> > +	  Annapurna Labs PCIe controller don't need to enable this.
> > +
> >  endmenu
> > diff --git a/drivers/pci/controller/dwc/pcie-al.c
> > b/drivers/pci/controller/dwc/pcie-al.c
> > index 3ab58f0584a8..40555532fb9a 100644
> > --- a/drivers/pci/controller/dwc/pcie-al.c
> > +++ b/drivers/pci/controller/dwc/pcie-al.c
> > @@ -91,3 +91,376 @@ struct pci_ecam_ops al_pcie_ops = {
> >  };
> >  
> >  #endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */
> > +
> > +#ifdef CONFIG_PCIE_AL
> > +
> > +#include <linux/of_pci.h>
> > +#include "pcie-designware.h"
> > +
> > +#define AL_PCIE_REV_ID_2	2
> > +#define AL_PCIE_REV_ID_3	3
> > +#define AL_PCIE_REV_ID_4	4
> > +
> > +#define AXI_BASE_OFFSET		0x0
> > +
> > +#define DEVICE_ID_OFFSET	0x16c
> > +
> > +#define DEVICE_REV_ID			0x0
> > +#define DEVICE_REV_ID_DEV_ID_MASK	GENMASK(31, 16)
> > +
> > +#define DEVICE_REV_ID_DEV_ID_X4		0
> > +#define DEVICE_REV_ID_DEV_ID_X8		2
> > +#define DEVICE_REV_ID_DEV_ID_X16	4
> > +
> > +#define OB_CTRL_REV1_2_OFFSET	0x0040
> > +#define OB_CTRL_REV3_5_OFFSET	0x0030
> > +
> > +#define CFG_TARGET_BUS			0x0
> > +#define CFG_TARGET_BUS_MASK_MASK	GENMASK(7, 0)
> > +#define CFG_TARGET_BUS_BUSNUM_MASK	GENMASK(15, 8)
> > +
> > +#define CFG_CONTROL			0x4
> > +#define CFG_CONTROL_SUBBUS_MASK		GENMASK(15, 8)
> > +#define CFG_CONTROL_SEC_BUS_MASK	GENMASK(23, 16)
> > +
> > +struct al_pcie_reg_offsets {
> > +	unsigned int ob_ctrl;
> > +};
> > +
> > +struct al_pcie_target_bus_cfg {
> > +	u8 reg_val;
> > +	u8 reg_mask;
> > +	u8 ecam_mask;
> > +};
> > +
> > +struct al_pcie {
> > +	struct dw_pcie *pci;
> > +	void __iomem *controller_base; /* base of PCIe unit (not DW
> > core) */
> > +	struct device *dev;
> > +	resource_size_t ecam_size;
> > +	unsigned int controller_rev_id;
> > +	struct al_pcie_reg_offsets reg_offsets;
> > +	struct al_pcie_target_bus_cfg target_bus_cfg;
> > +};
> > +
> > +#define PCIE_ECAM_DEVFN(x)		(((x) & 0xff) << 12)
> > +
> > +#define to_al_pcie(x)		dev_get_drvdata((x)->dev)
> > +
> > +static int al_pcie_rev_id_get(struct al_pcie *pcie, unsigned int
> > *rev_id)
> > +{
> > +	void __iomem *dev_rev_id_addr;
> > +	u32 dev_rev_id;
> > +
> > +	dev_rev_id_addr = (void __iomem *)((uintptr_t)pcie-
> > >controller_base +
> > +			  AXI_BASE_OFFSET + DEVICE_ID_OFFSET +
> > DEVICE_REV_ID);
> > +
> > +	dev_rev_id = FIELD_GET(DEVICE_REV_ID_DEV_ID_MASK,
> > +			       readl(dev_rev_id_addr));
> > +	switch (dev_rev_id) {
> > +	case DEVICE_REV_ID_DEV_ID_X4:
> > +		*rev_id = AL_PCIE_REV_ID_2;
> > +		break;
> > +	case DEVICE_REV_ID_DEV_ID_X8:
> > +		*rev_id = AL_PCIE_REV_ID_3;
> > +		break;
> > +	case DEVICE_REV_ID_DEV_ID_X16:
> > +		*rev_id = AL_PCIE_REV_ID_4;
> > +		break;
> > +	default:
> > +		dev_err(pcie->dev, "Unsupported dev_rev_id (0x%x)\n",
> > +			dev_rev_id);
> > +		return -EINVAL;
> > +	}
> > +
> > +	dev_dbg(pcie->dev, "dev_rev_id: 0x%x\n", dev_rev_id);
> 
> Consider s/dev_dbg/pci_dbg/g
> 
There is no struct pci_dev context (the dev belongs to the
platform_device).

> > +
> > +	return 0;
> > +}
> > +
> > +static int al_pcie_reg_offsets_set(struct al_pcie *pcie)
> > +{
> > +	switch (pcie->controller_rev_id) {
> > +	case AL_PCIE_REV_ID_2:
> > +		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV1_2_OFFSET;
> > +		break;
> > +	case AL_PCIE_REV_ID_3:
> > +	case AL_PCIE_REV_ID_4:
> > +		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV3_5_OFFSET;
> > +		break;
> > +	default:
> > +		dev_err(pcie->dev, "Unsupported controller rev_id:
> > 0x%x\n",
> > +			pcie->controller_rev_id);
> 
> Consider s/dev_err/pci_err/g
> 
Same as above.

> > +		return -EINVAL;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static inline void al_pcie_target_bus_set(struct al_pcie *pcie,
> > +					  u8 target_bus,
> > +					  u8 mask_target_bus)
> > +{
> > +	void __iomem *cfg_control_addr;
> > +	u32 reg;
> > +
> > +	reg = FIELD_PREP(CFG_TARGET_BUS_MASK_MASK, mask_target_bus) |
> > +	      FIELD_PREP(CFG_TARGET_BUS_BUSNUM_MASK, target_bus);
> > +
> > +	cfg_control_addr = (void __iomem *)((uintptr_t)pcie-
> > >controller_base +
> > +			   AXI_BASE_OFFSET + pcie->reg_offsets.ob_ctrl
> > +
> > +			   CFG_TARGET_BUS);
> > +
> > +	writel(reg, cfg_control_addr);
> 
> From what I'm seeing you commonly use writel() and readl() with a
> common 
> base address, such as pcie->controller_base + AXI_BASE_OFFSET.
> I'd suggest to creating a writel and readl with that offset built-in.
> 
I prefer to keep it generic, since in future revisions we might want to
access regs which are not in the AXI region. You think I should add
wrappers which simply hide the pcie->controller_base part?

> > +}
> > +
> > +static void __iomem *al_pcie_conf_addr_map(struct al_pcie *pcie,
> > +					   unsigned int busnr,
> > +					   unsigned int devfn)
> > +{
> > +	void __iomem *pci_base_addr;
> 
> Consider passing this variable declaration to the bottom, following
> the 
> reverse tree order.
> 
Done. Moved 'struct pcie_port *pp' as well.

> > +	struct pcie_port *pp = &pcie->pci->pp;
> > +	struct al_pcie_target_bus_cfg *target_bus_cfg = &pcie-
> > >target_bus_cfg;
> > +	unsigned int busnr_ecam = busnr & target_bus_cfg->ecam_mask;
> > +	unsigned int busnr_reg = busnr & target_bus_cfg->reg_mask;
> > +
> > +	pci_base_addr = (void __iomem *)((uintptr_t)pp->va_cfg0_base +
> > +					 (busnr_ecam << 20) +
> > +					 PCIE_ECAM_DEVFN(devfn));
> > +
> > +	if (busnr_reg != target_bus_cfg->reg_val) {
> > +		dev_dbg(pcie->pci->dev, "Changing target bus busnum val
> > from 0x%x to 0x%x\n",
> > +			target_bus_cfg->reg_val, busnr_reg);
> > +		target_bus_cfg->reg_val = busnr_reg;
> > +		al_pcie_target_bus_set(pcie,
> > +				       target_bus_cfg->reg_val,
> > +				       target_bus_cfg->reg_mask);
> > +	}
> > +
> > +	return pci_base_addr;
> > +}
> > +
> > +static int al_pcie_rd_other_conf(struct pcie_port *pp, struct
> > pci_bus *bus,
> > +				 unsigned int devfn, int where, int
> > size,
> > +				 u32 *val)
> > +{
> > +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> > +	struct al_pcie *pcie = to_al_pcie(pci);
> > +	unsigned int busnr = bus->number;
> > +	void __iomem *pci_addr;
> > +	int rc;
> > +
> > +	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
> > +
> > +	rc = dw_pcie_read(pci_addr + where, size, val);
> > +
> > +	dev_dbg(pci->dev, "%d-byte config read from %04x:%02x:%02x.%d
> > offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
> > +		size, pci_domain_nr(bus), bus->number,
> > +		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
> > +		(pci_addr + where), *val);
> > +
> > +	return rc;
> > +}
> > +
> > +static int al_pcie_wr_other_conf(struct pcie_port *pp, struct
> > pci_bus *bus,
> > +				 unsigned int devfn, int where, int
> > size,
> > +				 u32 val)
> > +{
> > +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> > +	struct al_pcie *pcie = to_al_pcie(pci);
> > +	unsigned int busnr = bus->number;
> > +	void __iomem *pci_addr;
> > +	int rc;
> > +
> > +	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
> > +
> > +	rc = dw_pcie_write(pci_addr + where, size, val);
> > +
> > +	dev_err(pci->dev, "%d-byte config write to %04x:%02x:%02x.%d
> > offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
> > +		size, pci_domain_nr(bus), bus->number,
> > +		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
> > +		(pci_addr + where), val);
> > +
> > +	return rc;
> > +}
> > +
> > +static int al_pcie_config_prepare(struct al_pcie *pcie)
> > +{
> > +	struct al_pcie_target_bus_cfg *target_bus_cfg;
> > +	struct pcie_port *pp = &pcie->pci->pp;
> > +	unsigned int ecam_bus_mask;
> > +	u8 secondary_bus;
> > +	u8 subordinate_bus;
> > +	void __iomem *cfg_control_addr;
> > +	u32 cfg_control;
> > +	u32 reg;
> > +
> > +	target_bus_cfg = &pcie->target_bus_cfg;
> > +
> > +	ecam_bus_mask = (pcie->ecam_size >> 20) - 1;
> > +	if (ecam_bus_mask > 255) {
> > +		dev_warn(pcie->dev, "ECAM window size is larger than
> > 256MB. Cutting off at 256\n");
> > +		ecam_bus_mask = 255;
> > +	}
> > +
> > +	/* This portion is taken from the transaction address */
> > +	target_bus_cfg->ecam_mask = ecam_bus_mask;
> > +	/* This portion is taken from the cfg_target_bus reg */
> > +	target_bus_cfg->reg_mask = ~target_bus_cfg->ecam_mask;
> > +	target_bus_cfg->reg_val = pp->busn->start & target_bus_cfg-
> > >reg_mask;
> > +
> > +	al_pcie_target_bus_set(pcie, target_bus_cfg->reg_val,
> > +			       target_bus_cfg->reg_mask);
> > +
> > +	secondary_bus = pp->busn->start + 1;
> > +	subordinate_bus = pp->busn->end;
> > +
> > +	/* Set the valid values of secondary and subordinate buses */
> > +	cfg_control_addr = pcie->controller_base + AXI_BASE_OFFSET +
> > +			   pcie->reg_offsets.ob_ctrl + CFG_CONTROL;
> > +
> > +	cfg_control = readl(cfg_control_addr);
> > +
> > +	reg = cfg_control &
> > +	      ~(CFG_CONTROL_SEC_BUS_MASK | CFG_CONTROL_SUBBUS_MASK);
> > +
> > +	reg |= FIELD_PREP(CFG_CONTROL_SUBBUS_MASK, subordinate_bus) |
> > +	       FIELD_PREP(CFG_CONTROL_SEC_BUS_MASK, secondary_bus);
> > +
> > +	writel(reg, cfg_control_addr);
> > +
> > +	return 0;
> > +}
> > +
> > +static int al_pcie_host_init(struct pcie_port *pp)
> > +{
> > +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> > +	struct al_pcie *pcie = to_al_pcie(pci);
> > +	int link_up;
> > +	int rc;
> > +
> > +	link_up = dw_pcie_link_up(pci);
> > +	if (!link_up) {
> > +		dev_err(pci->dev, "link is not up!\n");
> > +		return -ENOLINK;
> > +	}
> > +
> > +	dev_info(pci->dev, "link is up\n");
> 
> Consider s/dev_info/pci_info/g
> 
Same as the response above.

> > +
> > +	rc = al_pcie_rev_id_get(pcie, &pcie->controller_rev_id);
> > +	if (rc)
> > +		return rc;
> > +
> > +	rc = al_pcie_reg_offsets_set(pcie);
> > +	if (rc)
> > +		return rc;
> > +
> > +	rc = al_pcie_config_prepare(pcie);
> > +	if (rc)
> > +		return rc;
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct dw_pcie_host_ops al_pcie_host_ops = {
> > +	.rd_other_conf = al_pcie_rd_other_conf,
> > +	.wr_other_conf = al_pcie_wr_other_conf,
> > +	.host_init = al_pcie_host_init,
> > +};
> > +
> > +static int al_add_pcie_port(struct pcie_port *pp,
> > +			    struct platform_device *pdev)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	int ret;
> > +
> > +	pp->ops = &al_pcie_host_ops;
> > +
> > +	ret = dw_pcie_host_init(pp);
> > +	if (ret) {
> > +		dev_err(dev, "failed to initialize host\n");
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct dw_pcie_ops dw_pcie_ops = {
> > +};
> > +
> > +static int al_pcie_probe(struct platform_device *pdev)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct al_pcie *al_pcie;
> > +	struct dw_pcie *pci;
> > +	struct resource *dbi_res;
> > +	struct resource *controller_res;
> > +	struct resource *ecam_res;
> > +	int ret;
> 
> Please sort the variables following the reverse tree order.
> 
Done. 

I'd think that it would make sense to group variables which have a
common characteristic (e.g. resources read from the DT), even if it
mildly breaks the convention (as long as the general frame is longest
to shortest). Does this sound ok?

BTW, I couldn't find any documentation regarding the reverse-tree
convention, do you have a pointer to some?

> > +
> > +	al_pcie = devm_kzalloc(dev, sizeof(*al_pcie), GFP_KERNEL);
> > +	if (!al_pcie)
> > +		return -ENOMEM;
> > +
> > +	pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
> > +	if (!pci)
> > +		return -ENOMEM;
> > +
> > +	pci->dev = dev;
> > +	pci->ops = &dw_pcie_ops;
> > +
> > +	al_pcie->pci = pci;
> > +	al_pcie->dev = dev;
> > +
> > +	dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> > "dbi");
> > +	pci->dbi_base = devm_pci_remap_cfg_resource(dev, dbi_res);
> > +	if (IS_ERR(pci->dbi_base)) {
> > +		dev_err(dev, "couldn't remap dbi base %pR\n", dbi_res);
> > +		return PTR_ERR(pci->dbi_base);
> > +	}
> > +
> > +	ecam_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> > "config");
> > +	if (!ecam_res) {
> > +		dev_err(dev, "couldn't find 'config' reg in DT\n");
> > +		return -ENOENT;
> > +	}
> > +	al_pcie->ecam_size = resource_size(ecam_res);
> > +
> > +	controller_res = platform_get_resource_byname(pdev,
> > IORESOURCE_MEM,
> > +						      "controller");
> > +	al_pcie->controller_base = devm_ioremap_resource(dev,
> > controller_res);
> > +	if (IS_ERR(al_pcie->controller_base)) {
> > +		dev_err(dev, "couldn't remap controller base %pR\n",
> > +			controller_res);
> > +		return PTR_ERR(al_pcie->controller_base);
> > +	}
> > +
> > +	dev_dbg(dev, "From DT: dbi_base: %pR, controller_base: %pR\n",
> > +		dbi_res, controller_res);
> > +
> > +	platform_set_drvdata(pdev, al_pcie);
> > +
> > +	ret = al_add_pcie_port(&pci->pp, pdev);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return 0;
> 
> Those operations are redundant, aren't they? They can be replaced
> just 
> by:
> 
> return ret;
> 

Ack.

> > +}
> > +
> > +static const struct of_device_id al_pcie_of_match[] = {
> > +	{ .compatible = "amazon,al-pcie",
> > +	},
> > +	{},
> > +};
> > +
> > +static struct platform_driver al_pcie_driver = {
> > +	.driver = {
> > +		.name	= "al-pcie",
> > +		.of_match_table = al_pcie_of_match,
> > +		.suppress_bind_attrs = true,
> > +	},
> > +	.probe = al_pcie_probe,
> > +};
> > +builtin_platform_driver(al_pcie_driver);
> > +
> > +#endif /* CONFIG_PCIE_AL*/
> > -- 
> > 2.17.1
> 
>
Benjamin Herrenschmidt July 22, 2019, 12:47 a.m. UTC | #3
On Sun, 2019-07-21 at 15:08 +0000, Chocron, Jonathan wrote:
> > Please sort the variables following the reverse tree order.
> > 
> 
> Done. 
> 
> I'd think that it would make sense to group variables which have a
> common characteristic (e.g. resources read from the DT), even if it
> mildly breaks the convention (as long as the general frame is longest
> to shortest). Does this sound ok?
> 
> BTW, I couldn't find any documentation regarding the reverse-tree
> convention, do you have a pointer to some?

It's a complete stupidity that people who have nothing better to
comment about keep throwing at you when you are trying to get stuff
working.

Yes, we should avoid ugly stuff such as

	int rc;
	struct something_very_long foo;

But this definitely should come second to saner ordering such as the
one you propose of grouping related things together. At least IMHO.

You'll notice that the kernel these days attract way more people
interested in commenting to death on various minor points of coding
style than actual worthwhile technical comments on the code.

Cheers,
Ben.
Gustavo Pimentel July 22, 2019, 8:54 a.m. UTC | #4
On Sun, Jul 21, 2019 at 16:8:18, Chocron, Jonathan <jonnyc@amazon.com> 
wrote:

> On Fri, 2019-07-19 at 08:55 +0000, Gustavo Pimentel wrote:
> > On Thu, Jul 18, 2019 at 10:47:16, Jonathan Chocron <jonnyc@amazon.com
> > > 
> > wrote:
> > 
> > > This driver is DT based and utilizes the DesignWare APIs.
> > > It allows using a smaller ECAM range for a larger bus range -
> > > usually an entire bus uses 1MB of address space, but the driver
> > > can use it for a larger number of buses.
> > > 
> > > All link initializations are handled by the boot FW.
> > > 
> > > Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
> > > ---
> > >  drivers/pci/controller/dwc/Kconfig   |  12 +
> > >  drivers/pci/controller/dwc/pcie-al.c | 373
> > > +++++++++++++++++++++++++++
> > >  2 files changed, 385 insertions(+)
> > > 
> > > diff --git a/drivers/pci/controller/dwc/Kconfig
> > > b/drivers/pci/controller/dwc/Kconfig
> > > index 6ea778ae4877..3c6094cbcc3b 100644
> > > --- a/drivers/pci/controller/dwc/Kconfig
> > > +++ b/drivers/pci/controller/dwc/Kconfig
> > > @@ -230,4 +230,16 @@ config PCIE_UNIPHIER
> > >  	  Say Y here if you want PCIe controller support on UniPhier
> > > SoCs.
> > >  	  This driver supports LD20 and PXs3 SoCs.
> > >  
> > > +config PCIE_AL
> > > +	bool "Amazon Annapurna Labs PCIe controller"
> > > +	depends on OF && (ARM64 || COMPILE_TEST)
> > > +	depends on PCI_MSI_IRQ_DOMAIN
> > > +	select PCIE_DW_HOST
> > > +	help
> > > +	  Say Y here to enable support of the Amazon's Annapurna Labs
> > > PCIe
> > > +	  controller IP on Amazon SoCs. The PCIe controller uses the
> > > DesignWare
> > > +	  core plus Annapurna Labs proprietary hardware wrappers. This
> > > is
> > > +	  required only for DT-based platforms. ACPI platforms with the
> > > +	  Annapurna Labs PCIe controller don't need to enable this.
> > > +
> > >  endmenu
> > > diff --git a/drivers/pci/controller/dwc/pcie-al.c
> > > b/drivers/pci/controller/dwc/pcie-al.c
> > > index 3ab58f0584a8..40555532fb9a 100644
> > > --- a/drivers/pci/controller/dwc/pcie-al.c
> > > +++ b/drivers/pci/controller/dwc/pcie-al.c
> > > @@ -91,3 +91,376 @@ struct pci_ecam_ops al_pcie_ops = {
> > >  };
> > >  
> > >  #endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */
> > > +
> > > +#ifdef CONFIG_PCIE_AL
> > > +
> > > +#include <linux/of_pci.h>
> > > +#include "pcie-designware.h"
> > > +
> > > +#define AL_PCIE_REV_ID_2	2
> > > +#define AL_PCIE_REV_ID_3	3
> > > +#define AL_PCIE_REV_ID_4	4
> > > +
> > > +#define AXI_BASE_OFFSET		0x0
> > > +
> > > +#define DEVICE_ID_OFFSET	0x16c
> > > +
> > > +#define DEVICE_REV_ID			0x0
> > > +#define DEVICE_REV_ID_DEV_ID_MASK	GENMASK(31, 16)
> > > +
> > > +#define DEVICE_REV_ID_DEV_ID_X4		0
> > > +#define DEVICE_REV_ID_DEV_ID_X8		2
> > > +#define DEVICE_REV_ID_DEV_ID_X16	4
> > > +
> > > +#define OB_CTRL_REV1_2_OFFSET	0x0040
> > > +#define OB_CTRL_REV3_5_OFFSET	0x0030
> > > +
> > > +#define CFG_TARGET_BUS			0x0
> > > +#define CFG_TARGET_BUS_MASK_MASK	GENMASK(7, 0)
> > > +#define CFG_TARGET_BUS_BUSNUM_MASK	GENMASK(15, 8)
> > > +
> > > +#define CFG_CONTROL			0x4
> > > +#define CFG_CONTROL_SUBBUS_MASK		GENMASK(15, 8)
> > > +#define CFG_CONTROL_SEC_BUS_MASK	GENMASK(23, 16)
> > > +
> > > +struct al_pcie_reg_offsets {
> > > +	unsigned int ob_ctrl;
> > > +};
> > > +
> > > +struct al_pcie_target_bus_cfg {
> > > +	u8 reg_val;
> > > +	u8 reg_mask;
> > > +	u8 ecam_mask;
> > > +};
> > > +
> > > +struct al_pcie {
> > > +	struct dw_pcie *pci;
> > > +	void __iomem *controller_base; /* base of PCIe unit (not DW
> > > core) */
> > > +	struct device *dev;
> > > +	resource_size_t ecam_size;
> > > +	unsigned int controller_rev_id;
> > > +	struct al_pcie_reg_offsets reg_offsets;
> > > +	struct al_pcie_target_bus_cfg target_bus_cfg;
> > > +};
> > > +
> > > +#define PCIE_ECAM_DEVFN(x)		(((x) & 0xff) << 12)
> > > +
> > > +#define to_al_pcie(x)		dev_get_drvdata((x)->dev)
> > > +
> > > +static int al_pcie_rev_id_get(struct al_pcie *pcie, unsigned int
> > > *rev_id)
> > > +{
> > > +	void __iomem *dev_rev_id_addr;
> > > +	u32 dev_rev_id;
> > > +
> > > +	dev_rev_id_addr = (void __iomem *)((uintptr_t)pcie-
> > > >controller_base +
> > > +			  AXI_BASE_OFFSET + DEVICE_ID_OFFSET +
> > > DEVICE_REV_ID);
> > > +
> > > +	dev_rev_id = FIELD_GET(DEVICE_REV_ID_DEV_ID_MASK,
> > > +			       readl(dev_rev_id_addr));
> > > +	switch (dev_rev_id) {
> > > +	case DEVICE_REV_ID_DEV_ID_X4:
> > > +		*rev_id = AL_PCIE_REV_ID_2;
> > > +		break;
> > > +	case DEVICE_REV_ID_DEV_ID_X8:
> > > +		*rev_id = AL_PCIE_REV_ID_3;
> > > +		break;
> > > +	case DEVICE_REV_ID_DEV_ID_X16:
> > > +		*rev_id = AL_PCIE_REV_ID_4;
> > > +		break;
> > > +	default:
> > > +		dev_err(pcie->dev, "Unsupported dev_rev_id (0x%x)\n",
> > > +			dev_rev_id);
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	dev_dbg(pcie->dev, "dev_rev_id: 0x%x\n", dev_rev_id);
> > 
> > Consider s/dev_dbg/pci_dbg/g
> > 
> There is no struct pci_dev context (the dev belongs to the
> platform_device).

It seems so. It sucks...
Disregard this then.

> 
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int al_pcie_reg_offsets_set(struct al_pcie *pcie)
> > > +{
> > > +	switch (pcie->controller_rev_id) {
> > > +	case AL_PCIE_REV_ID_2:
> > > +		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV1_2_OFFSET;
> > > +		break;
> > > +	case AL_PCIE_REV_ID_3:
> > > +	case AL_PCIE_REV_ID_4:
> > > +		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV3_5_OFFSET;
> > > +		break;
> > > +	default:
> > > +		dev_err(pcie->dev, "Unsupported controller rev_id:
> > > 0x%x\n",
> > > +			pcie->controller_rev_id);
> > 
> > Consider s/dev_err/pci_err/g
> > 
> Same as above.
> 
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static inline void al_pcie_target_bus_set(struct al_pcie *pcie,
> > > +					  u8 target_bus,
> > > +					  u8 mask_target_bus)
> > > +{
> > > +	void __iomem *cfg_control_addr;
> > > +	u32 reg;
> > > +
> > > +	reg = FIELD_PREP(CFG_TARGET_BUS_MASK_MASK, mask_target_bus) |
> > > +	      FIELD_PREP(CFG_TARGET_BUS_BUSNUM_MASK, target_bus);
> > > +
> > > +	cfg_control_addr = (void __iomem *)((uintptr_t)pcie-
> > > >controller_base +
> > > +			   AXI_BASE_OFFSET + pcie->reg_offsets.ob_ctrl
> > > +
> > > +			   CFG_TARGET_BUS);
> > > +
> > > +	writel(reg, cfg_control_addr);
> > 
> > From what I'm seeing you commonly use writel() and readl() with a
> > common 
> > base address, such as pcie->controller_base + AXI_BASE_OFFSET.
> > I'd suggest to creating a writel and readl with that offset built-in.
> > 
> I prefer to keep it generic, since in future revisions we might want to
> access regs which are not in the AXI region. You think I should add
> wrappers which simply hide the pcie->controller_base part?

I and other developers typically do that, but it's a suggestion. IMHO it 
helps to keep the code cleaner and more readable.

> 
> > > +}
> > > +
> > > +static void __iomem *al_pcie_conf_addr_map(struct al_pcie *pcie,
> > > +					   unsigned int busnr,
> > > +					   unsigned int devfn)
> > > +{
> > > +	void __iomem *pci_base_addr;
> > 
> > Consider passing this variable declaration to the bottom, following
> > the 
> > reverse tree order.
> > 
> Done. Moved 'struct pcie_port *pp' as well.
> 
> > > +	struct pcie_port *pp = &pcie->pci->pp;
> > > +	struct al_pcie_target_bus_cfg *target_bus_cfg = &pcie-
> > > >target_bus_cfg;
> > > +	unsigned int busnr_ecam = busnr & target_bus_cfg->ecam_mask;
> > > +	unsigned int busnr_reg = busnr & target_bus_cfg->reg_mask;
> > > +
> > > +	pci_base_addr = (void __iomem *)((uintptr_t)pp->va_cfg0_base +
> > > +					 (busnr_ecam << 20) +
> > > +					 PCIE_ECAM_DEVFN(devfn));
> > > +
> > > +	if (busnr_reg != target_bus_cfg->reg_val) {
> > > +		dev_dbg(pcie->pci->dev, "Changing target bus busnum val
> > > from 0x%x to 0x%x\n",
> > > +			target_bus_cfg->reg_val, busnr_reg);
> > > +		target_bus_cfg->reg_val = busnr_reg;
> > > +		al_pcie_target_bus_set(pcie,
> > > +				       target_bus_cfg->reg_val,
> > > +				       target_bus_cfg->reg_mask);
> > > +	}
> > > +
> > > +	return pci_base_addr;
> > > +}
> > > +
> > > +static int al_pcie_rd_other_conf(struct pcie_port *pp, struct
> > > pci_bus *bus,
> > > +				 unsigned int devfn, int where, int
> > > size,
> > > +				 u32 *val)
> > > +{
> > > +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> > > +	struct al_pcie *pcie = to_al_pcie(pci);
> > > +	unsigned int busnr = bus->number;
> > > +	void __iomem *pci_addr;
> > > +	int rc;
> > > +
> > > +	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
> > > +
> > > +	rc = dw_pcie_read(pci_addr + where, size, val);
> > > +
> > > +	dev_dbg(pci->dev, "%d-byte config read from %04x:%02x:%02x.%d
> > > offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
> > > +		size, pci_domain_nr(bus), bus->number,
> > > +		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
> > > +		(pci_addr + where), *val);
> > > +
> > > +	return rc;
> > > +}
> > > +
> > > +static int al_pcie_wr_other_conf(struct pcie_port *pp, struct
> > > pci_bus *bus,
> > > +				 unsigned int devfn, int where, int
> > > size,
> > > +				 u32 val)
> > > +{
> > > +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> > > +	struct al_pcie *pcie = to_al_pcie(pci);
> > > +	unsigned int busnr = bus->number;
> > > +	void __iomem *pci_addr;
> > > +	int rc;
> > > +
> > > +	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
> > > +
> > > +	rc = dw_pcie_write(pci_addr + where, size, val);
> > > +
> > > +	dev_err(pci->dev, "%d-byte config write to %04x:%02x:%02x.%d
> > > offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
> > > +		size, pci_domain_nr(bus), bus->number,
> > > +		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
> > > +		(pci_addr + where), val);
> > > +
> > > +	return rc;
> > > +}
> > > +
> > > +static int al_pcie_config_prepare(struct al_pcie *pcie)
> > > +{
> > > +	struct al_pcie_target_bus_cfg *target_bus_cfg;
> > > +	struct pcie_port *pp = &pcie->pci->pp;
> > > +	unsigned int ecam_bus_mask;
> > > +	u8 secondary_bus;
> > > +	u8 subordinate_bus;
> > > +	void __iomem *cfg_control_addr;
> > > +	u32 cfg_control;
> > > +	u32 reg;
> > > +
> > > +	target_bus_cfg = &pcie->target_bus_cfg;
> > > +
> > > +	ecam_bus_mask = (pcie->ecam_size >> 20) - 1;
> > > +	if (ecam_bus_mask > 255) {
> > > +		dev_warn(pcie->dev, "ECAM window size is larger than
> > > 256MB. Cutting off at 256\n");
> > > +		ecam_bus_mask = 255;
> > > +	}
> > > +
> > > +	/* This portion is taken from the transaction address */
> > > +	target_bus_cfg->ecam_mask = ecam_bus_mask;
> > > +	/* This portion is taken from the cfg_target_bus reg */
> > > +	target_bus_cfg->reg_mask = ~target_bus_cfg->ecam_mask;
> > > +	target_bus_cfg->reg_val = pp->busn->start & target_bus_cfg-
> > > >reg_mask;
> > > +
> > > +	al_pcie_target_bus_set(pcie, target_bus_cfg->reg_val,
> > > +			       target_bus_cfg->reg_mask);
> > > +
> > > +	secondary_bus = pp->busn->start + 1;
> > > +	subordinate_bus = pp->busn->end;
> > > +
> > > +	/* Set the valid values of secondary and subordinate buses */
> > > +	cfg_control_addr = pcie->controller_base + AXI_BASE_OFFSET +
> > > +			   pcie->reg_offsets.ob_ctrl + CFG_CONTROL;
> > > +
> > > +	cfg_control = readl(cfg_control_addr);
> > > +
> > > +	reg = cfg_control &
> > > +	      ~(CFG_CONTROL_SEC_BUS_MASK | CFG_CONTROL_SUBBUS_MASK);
> > > +
> > > +	reg |= FIELD_PREP(CFG_CONTROL_SUBBUS_MASK, subordinate_bus) |
> > > +	       FIELD_PREP(CFG_CONTROL_SEC_BUS_MASK, secondary_bus);
> > > +
> > > +	writel(reg, cfg_control_addr);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int al_pcie_host_init(struct pcie_port *pp)
> > > +{
> > > +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> > > +	struct al_pcie *pcie = to_al_pcie(pci);
> > > +	int link_up;
> > > +	int rc;
> > > +
> > > +	link_up = dw_pcie_link_up(pci);
> > > +	if (!link_up) {
> > > +		dev_err(pci->dev, "link is not up!\n");
> > > +		return -ENOLINK;
> > > +	}
> > > +
> > > +	dev_info(pci->dev, "link is up\n");
> > 
> > Consider s/dev_info/pci_info/g
> > 
> Same as the response above.
> 
> > > +
> > > +	rc = al_pcie_rev_id_get(pcie, &pcie->controller_rev_id);
> > > +	if (rc)
> > > +		return rc;
> > > +
> > > +	rc = al_pcie_reg_offsets_set(pcie);
> > > +	if (rc)
> > > +		return rc;
> > > +
> > > +	rc = al_pcie_config_prepare(pcie);
> > > +	if (rc)
> > > +		return rc;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static const struct dw_pcie_host_ops al_pcie_host_ops = {
> > > +	.rd_other_conf = al_pcie_rd_other_conf,
> > > +	.wr_other_conf = al_pcie_wr_other_conf,
> > > +	.host_init = al_pcie_host_init,
> > > +};
> > > +
> > > +static int al_add_pcie_port(struct pcie_port *pp,
> > > +			    struct platform_device *pdev)
> > > +{
> > > +	struct device *dev = &pdev->dev;
> > > +	int ret;
> > > +
> > > +	pp->ops = &al_pcie_host_ops;
> > > +
> > > +	ret = dw_pcie_host_init(pp);
> > > +	if (ret) {
> > > +		dev_err(dev, "failed to initialize host\n");
> > > +		return ret;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static const struct dw_pcie_ops dw_pcie_ops = {
> > > +};
> > > +
> > > +static int al_pcie_probe(struct platform_device *pdev)
> > > +{
> > > +	struct device *dev = &pdev->dev;
> > > +	struct al_pcie *al_pcie;
> > > +	struct dw_pcie *pci;
> > > +	struct resource *dbi_res;
> > > +	struct resource *controller_res;
> > > +	struct resource *ecam_res;
> > > +	int ret;
> > 
> > Please sort the variables following the reverse tree order.
> > 
> Done. 
> 
> I'd think that it would make sense to group variables which have a
> common characteristic (e.g. resources read from the DT), even if it
> mildly breaks the convention (as long as the general frame is longest
> to shortest). Does this sound ok?
> 
> BTW, I couldn't find any documentation regarding the reverse-tree
> convention, do you have a pointer to some?

There isn't as far as I know, but it's a convention normally used in 
several subsystems.
I suppose it's a way to try to keep some organization along with the code 

style. IMHO it doesn't harm, but it's just a suggestion. 
Chocron, Jonathan July 22, 2019, 3:38 p.m. UTC | #5
On Mon, 2019-07-22 at 08:54 +0000, Gustavo Pimentel wrote:
> 
> > 
> > > > +static inline void al_pcie_target_bus_set(struct al_pcie
> > > > *pcie,
> > > > +					  u8 target_bus,
> > > > +					  u8 mask_target_bus)
> > > > +{
> > > > +	void __iomem *cfg_control_addr;
> > > > +	u32 reg;
> > > > +
> > > > +	reg = FIELD_PREP(CFG_TARGET_BUS_MASK_MASK,
> > > > mask_target_bus) |
> > > > +	      FIELD_PREP(CFG_TARGET_BUS_BUSNUM_MASK,
> > > > target_bus);
> > > > +
> > > > +	cfg_control_addr = (void __iomem *)((uintptr_t)pcie-
> > > > > controller_base +
> > > > 
> > > > +			   AXI_BASE_OFFSET + pcie-
> > > > >reg_offsets.ob_ctrl
> > > > +
> > > > +			   CFG_TARGET_BUS);
> > > > +
> > > > +	writel(reg, cfg_control_addr);
> > > 
> > > From what I'm seeing you commonly use writel() and readl() with a
> > > common 
> > > base address, such as pcie->controller_base + AXI_BASE_OFFSET.
> > > I'd suggest to creating a writel and readl with that offset
> > > built-in.
> > > 
> > 
> > I prefer to keep it generic, since in future revisions we might
> > want to
> > access regs which are not in the AXI region. You think I should add
> > wrappers which simply hide the pcie->controller_base part?
> 
> I and other developers typically do that, but it's a suggestion. IMHO
> it 
> helps to keep the code cleaner and more readable.
> 

Added al_pcie_controller_readl/writel wrappers.
Bjorn Helgaas July 22, 2019, 9:15 p.m. UTC | #6
On Sun, Jul 21, 2019 at 03:08:18PM +0000, Chocron, Jonathan wrote:
> On Fri, 2019-07-19 at 08:55 +0000, Gustavo Pimentel wrote:
> > On Thu, Jul 18, 2019 at 10:47:16, Jonathan Chocron <jonnyc@amazon.com> wrote:

> > > +static int al_pcie_probe(struct platform_device *pdev)
> > > +{
> > > +	struct device *dev = &pdev->dev;
> > > +	struct al_pcie *al_pcie;
> > > +	struct dw_pcie *pci;
> > > +	struct resource *dbi_res;
> > > +	struct resource *controller_res;
> > > +	struct resource *ecam_res;
> > > +	int ret;
> > 
> > Please sort the variables following the reverse tree order.
> > 
> Done. 
> 
> I'd think that it would make sense to group variables which have a
> common characteristic (e.g. resources read from the DT), even if it
> mildly breaks the convention (as long as the general frame is longest
> to shortest). Does this sound ok?
> 
> BTW, I couldn't find any documentation regarding the reverse-tree
> convention, do you have a pointer to some?

What I personally do is sort declarations in the order they're used.

Patch
diff mbox series

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 6ea778ae4877..3c6094cbcc3b 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -230,4 +230,16 @@  config PCIE_UNIPHIER
 	  Say Y here if you want PCIe controller support on UniPhier SoCs.
 	  This driver supports LD20 and PXs3 SoCs.
 
+config PCIE_AL
+	bool "Amazon Annapurna Labs PCIe controller"
+	depends on OF && (ARM64 || COMPILE_TEST)
+	depends on PCI_MSI_IRQ_DOMAIN
+	select PCIE_DW_HOST
+	help
+	  Say Y here to enable support of the Amazon's Annapurna Labs PCIe
+	  controller IP on Amazon SoCs. The PCIe controller uses the DesignWare
+	  core plus Annapurna Labs proprietary hardware wrappers. This is
+	  required only for DT-based platforms. ACPI platforms with the
+	  Annapurna Labs PCIe controller don't need to enable this.
+
 endmenu
diff --git a/drivers/pci/controller/dwc/pcie-al.c b/drivers/pci/controller/dwc/pcie-al.c
index 3ab58f0584a8..40555532fb9a 100644
--- a/drivers/pci/controller/dwc/pcie-al.c
+++ b/drivers/pci/controller/dwc/pcie-al.c
@@ -91,3 +91,376 @@  struct pci_ecam_ops al_pcie_ops = {
 };
 
 #endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */
+
+#ifdef CONFIG_PCIE_AL
+
+#include <linux/of_pci.h>
+#include "pcie-designware.h"
+
+#define AL_PCIE_REV_ID_2	2
+#define AL_PCIE_REV_ID_3	3
+#define AL_PCIE_REV_ID_4	4
+
+#define AXI_BASE_OFFSET		0x0
+
+#define DEVICE_ID_OFFSET	0x16c
+
+#define DEVICE_REV_ID			0x0
+#define DEVICE_REV_ID_DEV_ID_MASK	GENMASK(31, 16)
+
+#define DEVICE_REV_ID_DEV_ID_X4		0
+#define DEVICE_REV_ID_DEV_ID_X8		2
+#define DEVICE_REV_ID_DEV_ID_X16	4
+
+#define OB_CTRL_REV1_2_OFFSET	0x0040
+#define OB_CTRL_REV3_5_OFFSET	0x0030
+
+#define CFG_TARGET_BUS			0x0
+#define CFG_TARGET_BUS_MASK_MASK	GENMASK(7, 0)
+#define CFG_TARGET_BUS_BUSNUM_MASK	GENMASK(15, 8)
+
+#define CFG_CONTROL			0x4
+#define CFG_CONTROL_SUBBUS_MASK		GENMASK(15, 8)
+#define CFG_CONTROL_SEC_BUS_MASK	GENMASK(23, 16)
+
+struct al_pcie_reg_offsets {
+	unsigned int ob_ctrl;
+};
+
+struct al_pcie_target_bus_cfg {
+	u8 reg_val;
+	u8 reg_mask;
+	u8 ecam_mask;
+};
+
+struct al_pcie {
+	struct dw_pcie *pci;
+	void __iomem *controller_base; /* base of PCIe unit (not DW core) */
+	struct device *dev;
+	resource_size_t ecam_size;
+	unsigned int controller_rev_id;
+	struct al_pcie_reg_offsets reg_offsets;
+	struct al_pcie_target_bus_cfg target_bus_cfg;
+};
+
+#define PCIE_ECAM_DEVFN(x)		(((x) & 0xff) << 12)
+
+#define to_al_pcie(x)		dev_get_drvdata((x)->dev)
+
+static int al_pcie_rev_id_get(struct al_pcie *pcie, unsigned int *rev_id)
+{
+	void __iomem *dev_rev_id_addr;
+	u32 dev_rev_id;
+
+	dev_rev_id_addr = (void __iomem *)((uintptr_t)pcie->controller_base +
+			  AXI_BASE_OFFSET + DEVICE_ID_OFFSET + DEVICE_REV_ID);
+
+	dev_rev_id = FIELD_GET(DEVICE_REV_ID_DEV_ID_MASK,
+			       readl(dev_rev_id_addr));
+	switch (dev_rev_id) {
+	case DEVICE_REV_ID_DEV_ID_X4:
+		*rev_id = AL_PCIE_REV_ID_2;
+		break;
+	case DEVICE_REV_ID_DEV_ID_X8:
+		*rev_id = AL_PCIE_REV_ID_3;
+		break;
+	case DEVICE_REV_ID_DEV_ID_X16:
+		*rev_id = AL_PCIE_REV_ID_4;
+		break;
+	default:
+		dev_err(pcie->dev, "Unsupported dev_rev_id (0x%x)\n",
+			dev_rev_id);
+		return -EINVAL;
+	}
+
+	dev_dbg(pcie->dev, "dev_rev_id: 0x%x\n", dev_rev_id);
+
+	return 0;
+}
+
+static int al_pcie_reg_offsets_set(struct al_pcie *pcie)
+{
+	switch (pcie->controller_rev_id) {
+	case AL_PCIE_REV_ID_2:
+		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV1_2_OFFSET;
+		break;
+	case AL_PCIE_REV_ID_3:
+	case AL_PCIE_REV_ID_4:
+		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV3_5_OFFSET;
+		break;
+	default:
+		dev_err(pcie->dev, "Unsupported controller rev_id: 0x%x\n",
+			pcie->controller_rev_id);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static inline void al_pcie_target_bus_set(struct al_pcie *pcie,
+					  u8 target_bus,
+					  u8 mask_target_bus)
+{
+	void __iomem *cfg_control_addr;
+	u32 reg;
+
+	reg = FIELD_PREP(CFG_TARGET_BUS_MASK_MASK, mask_target_bus) |
+	      FIELD_PREP(CFG_TARGET_BUS_BUSNUM_MASK, target_bus);
+
+	cfg_control_addr = (void __iomem *)((uintptr_t)pcie->controller_base +
+			   AXI_BASE_OFFSET + pcie->reg_offsets.ob_ctrl +
+			   CFG_TARGET_BUS);
+
+	writel(reg, cfg_control_addr);
+}
+
+static void __iomem *al_pcie_conf_addr_map(struct al_pcie *pcie,
+					   unsigned int busnr,
+					   unsigned int devfn)
+{
+	void __iomem *pci_base_addr;
+	struct pcie_port *pp = &pcie->pci->pp;
+	struct al_pcie_target_bus_cfg *target_bus_cfg = &pcie->target_bus_cfg;
+	unsigned int busnr_ecam = busnr & target_bus_cfg->ecam_mask;
+	unsigned int busnr_reg = busnr & target_bus_cfg->reg_mask;
+
+	pci_base_addr = (void __iomem *)((uintptr_t)pp->va_cfg0_base +
+					 (busnr_ecam << 20) +
+					 PCIE_ECAM_DEVFN(devfn));
+
+	if (busnr_reg != target_bus_cfg->reg_val) {
+		dev_dbg(pcie->pci->dev, "Changing target bus busnum val from 0x%x to 0x%x\n",
+			target_bus_cfg->reg_val, busnr_reg);
+		target_bus_cfg->reg_val = busnr_reg;
+		al_pcie_target_bus_set(pcie,
+				       target_bus_cfg->reg_val,
+				       target_bus_cfg->reg_mask);
+	}
+
+	return pci_base_addr;
+}
+
+static int al_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
+				 unsigned int devfn, int where, int size,
+				 u32 *val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct al_pcie *pcie = to_al_pcie(pci);
+	unsigned int busnr = bus->number;
+	void __iomem *pci_addr;
+	int rc;
+
+	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
+
+	rc = dw_pcie_read(pci_addr + where, size, val);
+
+	dev_dbg(pci->dev, "%d-byte config read from %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
+		size, pci_domain_nr(bus), bus->number,
+		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
+		(pci_addr + where), *val);
+
+	return rc;
+}
+
+static int al_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
+				 unsigned int devfn, int where, int size,
+				 u32 val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct al_pcie *pcie = to_al_pcie(pci);
+	unsigned int busnr = bus->number;
+	void __iomem *pci_addr;
+	int rc;
+
+	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
+
+	rc = dw_pcie_write(pci_addr + where, size, val);
+
+	dev_err(pci->dev, "%d-byte config write to %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
+		size, pci_domain_nr(bus), bus->number,
+		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
+		(pci_addr + where), val);
+
+	return rc;
+}
+
+static int al_pcie_config_prepare(struct al_pcie *pcie)
+{
+	struct al_pcie_target_bus_cfg *target_bus_cfg;
+	struct pcie_port *pp = &pcie->pci->pp;
+	unsigned int ecam_bus_mask;
+	u8 secondary_bus;
+	u8 subordinate_bus;
+	void __iomem *cfg_control_addr;
+	u32 cfg_control;
+	u32 reg;
+
+	target_bus_cfg = &pcie->target_bus_cfg;
+
+	ecam_bus_mask = (pcie->ecam_size >> 20) - 1;
+	if (ecam_bus_mask > 255) {
+		dev_warn(pcie->dev, "ECAM window size is larger than 256MB. Cutting off at 256\n");
+		ecam_bus_mask = 255;
+	}
+
+	/* This portion is taken from the transaction address */
+	target_bus_cfg->ecam_mask = ecam_bus_mask;
+	/* This portion is taken from the cfg_target_bus reg */
+	target_bus_cfg->reg_mask = ~target_bus_cfg->ecam_mask;
+	target_bus_cfg->reg_val = pp->busn->start & target_bus_cfg->reg_mask;
+
+	al_pcie_target_bus_set(pcie, target_bus_cfg->reg_val,
+			       target_bus_cfg->reg_mask);
+
+	secondary_bus = pp->busn->start + 1;
+	subordinate_bus = pp->busn->end;
+
+	/* Set the valid values of secondary and subordinate buses */
+	cfg_control_addr = pcie->controller_base + AXI_BASE_OFFSET +
+			   pcie->reg_offsets.ob_ctrl + CFG_CONTROL;
+
+	cfg_control = readl(cfg_control_addr);
+
+	reg = cfg_control &
+	      ~(CFG_CONTROL_SEC_BUS_MASK | CFG_CONTROL_SUBBUS_MASK);
+
+	reg |= FIELD_PREP(CFG_CONTROL_SUBBUS_MASK, subordinate_bus) |
+	       FIELD_PREP(CFG_CONTROL_SEC_BUS_MASK, secondary_bus);
+
+	writel(reg, cfg_control_addr);
+
+	return 0;
+}
+
+static int al_pcie_host_init(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct al_pcie *pcie = to_al_pcie(pci);
+	int link_up;
+	int rc;
+
+	link_up = dw_pcie_link_up(pci);
+	if (!link_up) {
+		dev_err(pci->dev, "link is not up!\n");
+		return -ENOLINK;
+	}
+
+	dev_info(pci->dev, "link is up\n");
+
+	rc = al_pcie_rev_id_get(pcie, &pcie->controller_rev_id);
+	if (rc)
+		return rc;
+
+	rc = al_pcie_reg_offsets_set(pcie);
+	if (rc)
+		return rc;
+
+	rc = al_pcie_config_prepare(pcie);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+static const struct dw_pcie_host_ops al_pcie_host_ops = {
+	.rd_other_conf = al_pcie_rd_other_conf,
+	.wr_other_conf = al_pcie_wr_other_conf,
+	.host_init = al_pcie_host_init,
+};
+
+static int al_add_pcie_port(struct pcie_port *pp,
+			    struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	pp->ops = &al_pcie_host_ops;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(dev, "failed to initialize host\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+};
+
+static int al_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct al_pcie *al_pcie;
+	struct dw_pcie *pci;
+	struct resource *dbi_res;
+	struct resource *controller_res;
+	struct resource *ecam_res;
+	int ret;
+
+	al_pcie = devm_kzalloc(dev, sizeof(*al_pcie), GFP_KERNEL);
+	if (!al_pcie)
+		return -ENOMEM;
+
+	pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
+	if (!pci)
+		return -ENOMEM;
+
+	pci->dev = dev;
+	pci->ops = &dw_pcie_ops;
+
+	al_pcie->pci = pci;
+	al_pcie->dev = dev;
+
+	dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+	pci->dbi_base = devm_pci_remap_cfg_resource(dev, dbi_res);
+	if (IS_ERR(pci->dbi_base)) {
+		dev_err(dev, "couldn't remap dbi base %pR\n", dbi_res);
+		return PTR_ERR(pci->dbi_base);
+	}
+
+	ecam_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
+	if (!ecam_res) {
+		dev_err(dev, "couldn't find 'config' reg in DT\n");
+		return -ENOENT;
+	}
+	al_pcie->ecam_size = resource_size(ecam_res);
+
+	controller_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						      "controller");
+	al_pcie->controller_base = devm_ioremap_resource(dev, controller_res);
+	if (IS_ERR(al_pcie->controller_base)) {
+		dev_err(dev, "couldn't remap controller base %pR\n",
+			controller_res);
+		return PTR_ERR(al_pcie->controller_base);
+	}
+
+	dev_dbg(dev, "From DT: dbi_base: %pR, controller_base: %pR\n",
+		dbi_res, controller_res);
+
+	platform_set_drvdata(pdev, al_pcie);
+
+	ret = al_add_pcie_port(&pci->pp, pdev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct of_device_id al_pcie_of_match[] = {
+	{ .compatible = "amazon,al-pcie",
+	},
+	{},
+};
+
+static struct platform_driver al_pcie_driver = {
+	.driver = {
+		.name	= "al-pcie",
+		.of_match_table = al_pcie_of_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = al_pcie_probe,
+};
+builtin_platform_driver(al_pcie_driver);
+
+#endif /* CONFIG_PCIE_AL*/