Re: [PATCH v8 2/2] PCI: Rockchip: Add Rockchip PCIe controller support

[Bjorn Helgaas <helgaas@kernel.org>]

Hi Shawn,

You fixed some of the things I mentioned, but not all, and you
over-fixed some things, leading to issues.

On Fri, Jul 29, 2016 at 10:48:13AM +0800, Shawn Lin wrote:
> This patch adds Rockchip PCIe controller support found
> on RK3399 Soc platform.
> 
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> 
> Reviewed-by: Brian Norris <briannorris@chromium.org>
> ---
> 
> Changes in v8:
> - fix all the comments suggested by Bjorn Helgaas in v7[1]
>   [1] https://patchwork.kernel.org/patch/9233887/
> - enable bandwith interrupt for debug
> 
> Changes in v7:
> - make it as a build-in driver
> - improve gen1/2 training timeout checking
> - only clear known interrupt
> - fix INTx for 0-base index
> 
> Changes in v6:
> - use "depends on PCI_MSI_IRQ_DOMAIN" suggested by Arnd
> 
> Changes in v5:
> - handle multiple pending INTx at the same time
>   suggested by Marc
> 
> Changes in v4:
> - address the comments from Brain
> 
> Changes in v3:
> - remove header file
> - remove struct msi_controller and move most of variables
>   of rockchip_pcie_port to become the local ones.
> - allow legacy int even if enabling MSI
> - drop regulator set voltage operation suggested by Doug
> 
> Changes in v2:
> - remove phy related stuff and call phy API
> - add new head file and define lots of macro to make
>   the code more readable
> - remove lots msi related code suggested by Marc
> - add IO window address translation
> - init_port and parse_dt reconstruction suggested by Bharat
> - improve wr_own_conf suggested by Arnd
> - make pcie as an interrupt controller and fix wrong int handler
>   suggested by Marc
> - remove PCI_PROBE_ONLY suggested by Lorenzo
> 
>  drivers/pci/host/Kconfig         |   11 +
>  drivers/pci/host/Makefile        |    1 +
>  drivers/pci/host/pcie-rockchip.c | 1257 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1269 insertions(+)
>  create mode 100644 drivers/pci/host/pcie-rockchip.c
> 
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index c917e2f..4d714d2 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -264,4 +264,15 @@ config PCIE_ARTPEC6
>  	  Say Y here to enable PCIe controller support on Axis ARTPEC-6
>  	  SoCs.  This PCIe controller uses the DesignWare core.
>  
> +config PCIE_ROCKCHIP
> +	bool "Rockchip PCIe controller"
> +	depends on ARM64 && ARCH_ROCKCHIP
> +	depends on OF
> +	depends on PCI_MSI_IRQ_DOMAIN
> +	select MFD_SYSCON
> +	help
> +	  Say Y here if you want internal PCI support on Rockchip SoC.
> +	  There is 1 internal PCIe port available to support GEN2 with
> +	  4 slots.
> +
>  endmenu
> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> index 5bc0af2..695f716 100644
> --- a/drivers/pci/host/Makefile
> +++ b/drivers/pci/host/Makefile
> @@ -30,3 +30,4 @@ obj-$(CONFIG_PCI_HOST_THUNDER_ECAM) += pci-thunder-ecam.o
>  obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o
>  obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
>  obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
> +obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o
> diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
> new file mode 100644
> index 0000000..13ac199
> --- /dev/null
> +++ b/drivers/pci/host/pcie-rockchip.c
> @@ -0,0 +1,1257 @@
> +/*
> + * Rockchip AXI PCIe host controller driver
> + *
> + * Copyright (c) 2016 Rockchip, Inc.
> + *
> + * Author: Shawn Lin <shawn.lin@rock-chips.com>
> + *         Wenrui Li <wenrui.li@rock-chips.com>
> + *
> + * Bits taken from Synopsys Designware Host controller driver and
> + * ARM PCI Host generic driver.
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/of_pci.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_irq.h>
> +#include <linux/pci.h>
> +#include <linux/pci_ids.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include <linux/regmap.h>
> +

Indent all the following constants with tabs, not spaces.

> +#define PCIE_CLIENT_BASE                   0x0
> +#define PCIE_RC_CONFIG_NORMAL_BASE         0x800000
> +#define PCIE_RC_CONFIG_BASE                0xa00000

> +#define PCIE_RC_CONFIG_LCSR_OFFSET         0xd0
> +#define PCIE_RC_CONFIG_LCSR_BW_ENA         0x1
> +#define PCIE_RC_CONFIG_LCSR_LBMIE          BIT(10)
> +#define PCIE_RC_CONFIG_LCSR_LABIE          BIT(11)
> +#define PCIE_RC_CONFIG_LCSR_LBMS           BIT(30)
> +#define PCIE_RC_CONFIG_LCSR_LAMS           BIT(31)

This section looks like the offset and fields in one register (LCSR).

1) Remove "_OFFSET".  You don't use it on similar registers below,
e.g., IE_CORE_OB_REGION_ADDR1.

2) Indent the field definitions a space or two to show the association
with the register name, e.g.,

  #define PCIE_RC_CONFIG_LCSR                0xd0
  #define   PCIE_RC_CONFIG_LCSR_BW_ENA       0x1

3) Make the field definition the same width as the register.  In this
case, you use readl, so it would be:

  #define   PCIE_RC_CONFIG_LCSR_BW_ENA       0x00000001

4) Use the same type of definition (plain hex value vs. BIT()) for all
fields in a register.  BIT(x) likely maps to your documentation, but
my personal preference is the plain hex value because it's simpler to
debug, it shows the register width, and it works nicely for multi-bit
fields.  I guess GENMASK() is one way to handle multi-bit fields, too.
Whichever you choose, use it consistently.

> +#define PCIE_CORE_LINK_CTRL_STATUS         0x8000d0

Unused, remove.

> +#define PCIE_CORE_CTRL_MGMT_BASE           0x900000
> +#define PCIE_CORE_AXI_CONF_BASE            0xc00000
> +#define PCIE_CORE_AXI_INBOUND_BASE         0xc00800
> +#define PCIE_CLIENT_BASIC_STATUS0          0x44

Unused, remove.

> +#define PCIE_CLIENT_BASIC_STATUS1          0x48
> +#define PCIE_CLIENT_INT_MASK               0x4c
> +#define PCIE_CLIENT_INT_STATUS             0x50
> +#define PCIE_CLIENT_INT_LEGACY_DONE        BIT(15)
> +#define PCIE_CLIENT_INT_MSG                BIT(14)
> +#define PCIE_CLIENT_INT_HOT_RST            BIT(13)
> +#define PCIE_CLIENT_INT_DPA                BIT(12)
> +#define PCIE_CLIENT_INT_FATAL_ERR          BIT(11)
> +#define PCIE_CLIENT_INT_NFATAL_ERR         BIT(10)
> +#define PCIE_CLIENT_INT_CORR_ERR           BIT(9)
> +#define PCIE_CLIENT_INT_INTD               BIT(8)
> +#define PCIE_CLIENT_INT_INTC               BIT(7)
> +#define PCIE_CLIENT_INT_INTB               BIT(6)
> +#define PCIE_CLIENT_INT_INTA               BIT(5)
> +#define PCIE_CLIENT_INT_LOCAL              BIT(4)
> +#define PCIE_CLIENT_INT_UDMA               BIT(3)
> +#define PCIE_CLIENT_INT_PHY                BIT(2)
> +#define PCIE_CLIENT_INT_HOT_PLUG           BIT(1)
> +#define PCIE_CLIENT_INT_PWR_STCG           BIT(0)
> +#define PCIE_RC_CONFIG_RID_CCR             0x8
> +#define PCIE_RC_CONFIG_LCS                 0xd0
> +#define PCIE_RC_BAR_CONF                   0x300
> +#define PCIE_CORE_OB_REGION_ADDR1          0x4
> +#define PCIE_CORE_OB_REGION_DESC0          0x8
> +#define PCIE_CORE_OB_REGION_DESC1          0xc
> +#define PCIE_CORE_OB_REGION_ADDR0_NUM_BITS 0x3fU

Why do some of these constants have "U" and others not?  I don't think
they're needed.

> +#define PCIE_CORE_OB_REGION_ADDR0_LO_ADDR  0xffffff00U
> +#define PCIE_CORE_IB_REGION_ADDR0_NUM_BITS 0x3fU
> +#define PCIE_CORE_IB_REGION_ADDR0_LO_ADDR  0xffffff00U
> +#define PCIE_RP_IB_ADDR_TRANS              0x4
> +#define PCIE_CORE_INT_MASK                 0x900210
> +#define PCIE_CORE_INT_STATUS               0x90020c
> +#define PCIE_CORE_INT_PRFPE                BIT(0)
> +#define PCIE_CORE_INT_CRFPE                BIT(1)
> +#define PCIE_CORE_INT_RRPE                 BIT(2)
> +#define PCIE_CORE_INT_PRFO                 BIT(3)
> +#define PCIE_CORE_INT_CRFO                 BIT(4)
> +#define PCIE_CORE_INT_RT                   BIT(5)
> +#define PCIE_CORE_INT_RTR                  BIT(6)
> +#define PCIE_CORE_INT_PE                   BIT(7)
> +#define PCIE_CORE_INT_MTR                  BIT(8)
> +#define PCIE_CORE_INT_UCR                  BIT(9)
> +#define PCIE_CORE_INT_FCE                  BIT(10)
> +#define PCIE_CORE_INT_CT                   BIT(11)
> +#define PCIE_CORE_INT_UTC                  BIT(18)
> +#define PCIE_CORE_INT_MMVC                 BIT(19)
> +
> +/* Size of one AXI Region (not Region 0) */
> +#define AXI_REGION_SIZE                    BIT(20)
> +/* Size of Region 0, equal to sum of sizes of other regions */
> +#define AXI_REGION_0_SIZE                 (32 * (0x1 << 20))
> +#define OB_REG_SIZE_SHIFT                  5
> +#define IB_ROOT_PORT_REG_SIZE_SHIFT        3
> +#define AXI_WRAPPER_IO_WRITE               0x6
> +#define AXI_WRAPPER_MEM_WRITE              0x2

This could do with a blank line.  The below are not directly
associated with the registers above.

> +#define MAX_AXI_IB_ROOTPORT_REGION_NUM     3
> +#define MIN_AXI_ADDR_BITS_PASSED           8
> +#define ROCKCHIP_VENDOR_ID                 0x1d87
> +#define PCIE_ECAM_BUS(x)		  (((x) & 0xff) << 20)
> +#define PCIE_ECAM_DEV(x)		  (((x) & 0x1f) << 15)
> +#define PCIE_ECAM_FUNC(x)		  (((x) & 0x7) << 12)
> +#define PCIE_ECAM_REG(x)		  (((x) & 0xfff) << 0)
> +#define PCIE_ECAM_ADDR(bus, dev, func, reg) \
> +	  (PCIE_ECAM_BUS(bus) | PCIE_ECAM_DEV(dev) | \
> +	   PCIE_ECAM_FUNC(func) | PCIE_ECAM_REG(reg))
> +
> +/*
> +  * The higher 16-bit of this register is used for write protection
> +  * only if BIT(x + 16) set to 1 the BIT(x) can be written.
> +  */
> +#define HIWORD_UPDATE(val, mask, shift) \
> +	((val) << (shift) | (mask) << ((shift) + 16))
> +
> +#define RC_REGION_0_ADDR_TRANS_H          0x00000000
> +#define RC_REGION_0_ADDR_TRANS_L          0x00000000
> +#define RC_REGION_0_PASS_BITS             (25 - 1)
> +#define RC_REGION_1_ADDR_TRANS_H          0x00000000
> +#define RC_REGION_1_ADDR_TRANS_L          0x00400000
> +#define RC_REGION_1_PASS_BITS             (20 - 1)
> +#define MAX_AXI_WRAPPER_REGION_NUM        33
> +#define PCIE_CORE_LCSR_RETRAIN_LINK       BIT(5)
> +#define PCIE_CLIENT_CONF_ENABLE           1
> +#define PCIE_CLIENT_CONF_ENABLE_SHIFT     0
> +#define PCIE_CLIENT_CONF_ENABLE_MASK      0x1
> +#define PCIE_CLIENT_LINK_TRAIN_ENABLE     1
> +#define PCIE_CLIENT_LINK_TRAIN_SHIFT      1
> +#define PCIE_CLIENT_LINK_TRAIN_MASK       0x1
> +#define PCIE_CLIENT_ARI_ENABLE            1
> +#define PCIE_CLIENT_ARI_ENABLE_SHIFT      3
> +#define PCIE_CLIENT_ARI_ENABLE_MASK       0x1
> +#define PCIE_CLIENT_CONF_LANE_NUM(x)      (x / 2)
> +#define PCIE_CLIENT_CONF_LANE_NUM_SHIFT   4
> +#define PCIE_CLIENT_CONF_LANE_NUM_MASK    0x3
> +#define PCIE_CLIENT_MODE_RC               1
> +#define PCIE_CLIENT_MODE_SHIFT            6
> +#define PCIE_CLIENT_MODE_MASK             0x1
> +#define PCIE_CLIENT_GEN_SEL_2             1
> +#define PCIE_CLIENT_GEN_SEL_1             0
> +#define PCIE_CLIENT_GEN_SEL_SHIFT         7
> +#define PCIE_CLIENT_GEN_SEL_MASK          0x1
> +#define PCIE_CLIENT_LINK_STATUS_UP        0x3
> +#define PCIE_CLIENT_LINK_STATUS_SHIFT     20
> +#define PCIE_CLIENT_LINK_STATUS_MASK      0x3
> +#define PCIE_CORE_PL_CONF_SPEED_2_5G      0x0
> +#define PCIE_CORE_PL_CONF_SPEED_5G        0x1
> +#define PCIE_CORE_PL_CONF_SPEED_8G        0x2
> +#define PCIE_CORE_PL_CONF_SPEED_SHIFT     3
> +#define PCIE_CORE_PL_CONF_SPEED_MASK      0x3
> +#define PCIE_CORE_PL_CONF_LANE_SHIFT      1
> +#define PCIE_CORE_PL_CONF_LANE_MASK       0x3
> +#define PCIE_CORE_RC_CONF_SCC_SHIFT       16
> +
> +#define ROCKCHIP_PCIE_RPIFR1_INTR_MASK    GENMASK(8, 5)
> +#define ROCKCHIP_PCIE_RPIFR1_INTR_SHIFT   5
> +
> +#define PCIE_CORE_INT \
> +		(PCIE_CORE_INT_PRFPE | PCIE_CORE_INT_CRFPE | \
> +		 PCIE_CORE_INT_RRPE | PCIE_CORE_INT_CRFO | \
> +		 PCIE_CORE_INT_RT | PCIE_CORE_INT_RTR | \
> +		 PCIE_CORE_INT_PE | PCIE_CORE_INT_MTR | \
> +		 PCIE_CORE_INT_UCR | PCIE_CORE_INT_FCE | \
> +		 PCIE_CORE_INT_CT | PCIE_CORE_INT_UTC | \
> +		 PCIE_CORE_INT_MMVC)
> +
> +#define PCIE_CLIENT_INT_SUBSYSTEM \
> +	(PCIE_CLIENT_INT_PWR_STCG | PCIE_CLIENT_INT_HOT_PLUG | \
> +	PCIE_CLIENT_INT_PHY | PCIE_CLIENT_INT_UDMA | \
> +	PCIE_CLIENT_INT_LOCAL)
> +
> +#define PCIE_CLIENT_INT_LEGACY \
> +	(PCIE_CLIENT_INT_INTA | PCIE_CLIENT_INT_INTB | \
> +	PCIE_CLIENT_INT_INTC | PCIE_CLIENT_INT_INTD)
> +
> +#define PCIE_CLIENT_INT_CLI \
> +	(PCIE_CLIENT_INT_CORR_ERR | PCIE_CLIENT_INT_NFATAL_ERR | \
> +	PCIE_CLIENT_INT_FATAL_ERR | PCIE_CLIENT_INT_DPA | \
> +	PCIE_CLIENT_INT_HOT_RST | PCIE_CLIENT_INT_MSG | \
> +	PCIE_CLIENT_INT_LEGACY_DONE | PCIE_CLIENT_INT_LEGACY | \
> +	PCIE_CLIENT_INT_PHY)
> +
> +struct rockchip_pcie_port {
> +	void	__iomem *reg_base;
> +	void	__iomem *apb_base;
> +	struct	phy *phy;
> +	struct	reset_control *core_rst;
> +	struct	reset_control *mgmt_rst;
> +	struct	reset_control *mgmt_sticky_rst;
> +	struct	reset_control *pipe_rst;
> +	struct	clk *aclk_pcie;
> +	struct	clk *aclk_perf_pcie;
> +	struct	clk *hclk_pcie;
> +	struct	clk *clk_pcie_pm;
> +	struct	regulator *vpcie3v3; /* 3.3V power supply */
> +	struct	regulator *vpcie1v8; /* 1.8V power supply */
> +	struct	regulator *vpcie0v9; /* 0.9V power supply */
> +	struct	gpio_desc *ep_gpio;
> +	u32	lanes;
> +	u8	root_bus_nr;
> +	struct	device *dev;
> +	struct	irq_domain *irq_domain;
> +};
> +
> +static inline u32 pcie_read(struct rockchip_pcie_port *port, u32 reg)
> +{
> +	return readl(port->apb_base + reg);
> +}
> +
> +static inline void pcie_write(struct rockchip_pcie_port *port,
> +			      u32 val, u32 reg)
> +{
> +	writel(val, port->apb_base + reg);
> +}
> +
> +static void rockchip_pcie_enable_bw_int(struct rockchip_pcie_port *port)
> +{
> +	u32 status;
> +
> +	status = pcie_read(port, PCIE_RC_CONFIG_BASE +
> +				 PCIE_RC_CONFIG_LCSR_OFFSET);
> +	status |= (PCIE_RC_CONFIG_LCSR_LBMIE | PCIE_RC_CONFIG_LCSR_LABIE);
> +	pcie_write(port, status, PCIE_RC_CONFIG_BASE +
> +				 PCIE_RC_CONFIG_LCSR_OFFSET);
> +}
> +
> +static void rockchip_pcie_clr_bw_int(struct rockchip_pcie_port *port)
> +{
> +	u32 status;
> +
> +	status = pcie_read(port, PCIE_RC_CONFIG_BASE +
> +				 PCIE_RC_CONFIG_LCSR_OFFSET);
> +	status |= (PCIE_RC_CONFIG_LCSR_LBMS | PCIE_RC_CONFIG_LCSR_LAMS);
> +	pcie_write(port, status, PCIE_RC_CONFIG_BASE +
> +				 PCIE_RC_CONFIG_LCSR_OFFSET);
> +}
> +
> +static int rockchip_pcie_valid_config(struct rockchip_pcie_port *pp,
> +				      struct pci_bus *bus, int dev)
> +{
> +	/* access only one slot on each root port */
> +	if (bus->number == pp->root_bus_nr && dev > 0)
> +		return 0;
> +
> +	/*
> +	 * do not read more than one device on the bus directly attached
> +	 * to RC's downstream side.
> +	 */
> +	if (bus->primary == pp->root_bus_nr && dev > 0)
> +		return 0;
> +
> +	return 1;
> +}
> +
> +static int rockchip_pcie_rd_own_conf(struct rockchip_pcie_port *pp,
> +				     int where, int size,
> +				     u32 *val)
> +{
> +	void __iomem *addr = pp->apb_base + PCIE_RC_CONFIG_BASE + where;
> +
> +	if (!IS_ALIGNED((uintptr_t)addr, size)) {
> +		*val = 0;
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +	}
> +
> +	if (size == 4) {
> +		*val = readl(addr);
> +	} else if (size == 2) {
> +		*val = readw(addr);
> +	} else if (size == 1) {
> +		*val = readb(addr);
> +	} else {
> +		*val = 0;
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +	}
> +	return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static int rockchip_pcie_wr_own_conf(struct rockchip_pcie_port *pp,
> +				     int where, int size, u32 val)
> +{
> +	u32 mask, tmp, offset;
> +
> +	offset = (where & (~0x3));
> +
> +	if (size == 4) {
> +		writel(val, pp->apb_base + PCIE_RC_CONFIG_BASE + offset);
> +		return PCIBIOS_SUCCESSFUL;
> +	}
> +
> +	mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8));
> +
> +	tmp = readl(pp->apb_base + PCIE_RC_CONFIG_BASE + offset) & mask;
> +	tmp |= val << ((where & 0x3) * 8);
> +	writel(tmp, pp->apb_base + PCIE_RC_CONFIG_BASE + offset);
> +
> +	return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static int rockchip_pcie_rd_other_conf(struct rockchip_pcie_port *pp,
> +				       struct pci_bus *bus, u32 devfn,
> +				       int where, int size, u32 *val)
> +{
> +	u32 busdev;
> +
> +	busdev = PCIE_ECAM_ADDR(bus->number, PCI_SLOT(devfn),
> +				PCI_FUNC(devfn), where);
> +
> +	if (!IS_ALIGNED(busdev, size)) {
> +		*val = 0;
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +	}
> +
> +	if (size == 4) {
> +		*val = readl(pp->reg_base + busdev);
> +	} else if (size == 2) {
> +		*val = readw(pp->reg_base + busdev);
> +	} else if (size == 1) {
> +		*val = readb(pp->reg_base + busdev);
> +	} else {
> +		*val = 0;
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +	}
> +	return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static int rockchip_pcie_wr_other_conf(struct rockchip_pcie_port *pp,
> +				       struct pci_bus *bus, u32 devfn,
> +				       int where, int size, u32 val)
> +{
> +	u32 busdev;
> +
> +	busdev = PCIE_ECAM_ADDR(bus->number, PCI_SLOT(devfn),
> +				PCI_FUNC(devfn), where);
> +	if (!IS_ALIGNED(busdev, size))
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +
> +	if (size == 4)
> +		writel(val, pp->reg_base + busdev);
> +	else if (size == 2)
> +		writew(val, pp->reg_base + busdev);
> +	else if (size == 1)
> +		writeb(val, pp->reg_base + busdev);
> +	else
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +
> +	return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static int rockchip_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
> +				 int size, u32 *val)
> +{
> +	struct rockchip_pcie_port *pp = bus->sysdata;
> +
> +	if (rockchip_pcie_valid_config(pp, bus, PCI_SLOT(devfn)) == 0) {
> +		*val = 0xffffffff;
> +		return PCIBIOS_DEVICE_NOT_FOUND;
> +	}
> +
> +	if (bus->number != pp->root_bus_nr)
> +		return rockchip_pcie_rd_other_conf(pp, bus, devfn,
> +						  where, size, val);
> +
> +	return rockchip_pcie_rd_own_conf(pp, where, size, val);

You only did this half-way:

1) Do this instead to avoid the negation:

  if (bus->number == pp->root_bus_nr)
    return rockchip_pcie_rd_own_conf(pp, where, size, val);

  return rockchip_pcie_rd_other_conf(pp, bus, devfn, ...);

2) Apply the same change to rockchip_pcie_wr_conf() below.

> +}
> +
> +static int rockchip_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
> +				 int where, int size, u32 val)
> +{
> +	struct rockchip_pcie_port *pp = bus->sysdata;
> +	int ret;
> +
> +	if (rockchip_pcie_valid_config(pp, bus, PCI_SLOT(devfn)) == 0)
> +		return PCIBIOS_DEVICE_NOT_FOUND;
> +
> +	if (bus->number != pp->root_bus_nr)
> +		ret = rockchip_pcie_wr_other_conf(pp, bus, devfn,
> +						  where, size, val);
> +	else
> +		ret = rockchip_pcie_wr_own_conf(pp, where, size, val);
> +
> +	return ret;
> +}
> +
> +static struct pci_ops rockchip_pcie_ops = {
> +	.read = rockchip_pcie_rd_conf,
> +	.write = rockchip_pcie_wr_conf,
> +};
> +
> +/**
> + * rockchip_pcie_init_port - Initialize hardware
> + * @port: PCIe port information
> + */
> +static int rockchip_pcie_init_port(struct rockchip_pcie_port *port)
> +{
> +	int err;
> +	u32 status;
> +	unsigned long timeout;
> +
> +	gpiod_set_value(port->ep_gpio, 0);
> +
> +	err = phy_init(port->phy);
> +	if (err < 0) {
> +		dev_err(port->dev, "fail to init phy, err %d\n", err);
> +		return err;
> +	}
> +
> +	err = reset_control_assert(port->core_rst);
> +	if (err) {
> +		dev_err(port->dev, "assert core_rst err %d\n", err);
> +		return err;
> +	}
> +
> +	err = reset_control_assert(port->mgmt_rst);
> +	if (err) {
> +		dev_err(port->dev, "assert mgmt_rst err %d\n", err);
> +		return err;
> +	}
> +
> +	err = reset_control_assert(port->mgmt_sticky_rst);
> +	if (err) {
> +		dev_err(port->dev, "assert mgmt_sticky_rst err %d\n", err);
> +		return err;
> +	}
> +
> +	err = reset_control_assert(port->pipe_rst);
> +	if (err) {
> +		dev_err(port->dev, "assert pipe_rst err %d\n", err);
> +		return err;
> +	}
> +
> +	pcie_write(port,
> +		   HIWORD_UPDATE(PCIE_CLIENT_CONF_ENABLE,
> +				 PCIE_CLIENT_CONF_ENABLE_MASK,
> +				 PCIE_CLIENT_CONF_ENABLE_SHIFT) |
> +		   HIWORD_UPDATE(PCIE_CLIENT_CONF_LANE_NUM(port->lanes),
> +				 PCIE_CLIENT_CONF_LANE_NUM_MASK,
> +				 PCIE_CLIENT_CONF_LANE_NUM_SHIFT) |
> +		   HIWORD_UPDATE(PCIE_CLIENT_MODE_RC,
> +				 PCIE_CLIENT_MODE_MASK,
> +				 PCIE_CLIENT_MODE_SHIFT) |
> +		   HIWORD_UPDATE(PCIE_CLIENT_ARI_ENABLE,
> +				 PCIE_CLIENT_ARI_ENABLE_MASK,
> +				 PCIE_CLIENT_ARI_ENABLE_SHIFT) |
> +		   HIWORD_UPDATE(PCIE_CLIENT_GEN_SEL_2,
> +				 PCIE_CLIENT_GEN_SEL_MASK,
> +				 PCIE_CLIENT_GEN_SEL_SHIFT),
> +		   PCIE_CLIENT_BASE);
> +
> +	err = phy_power_on(port->phy);
> +	if (err) {
> +		dev_err(port->dev, "fail to power on phy, err %d\n", err);
> +		return err;
> +	}
> +
> +	err = reset_control_deassert(port->core_rst);
> +	if (err) {
> +		dev_err(port->dev, "deassert core_rst err %d\n", err);
> +		return err;
> +	}
> +
> +	err = reset_control_deassert(port->mgmt_rst);
> +	if (err) {
> +		dev_err(port->dev, "deassert mgmt_rst err %d\n", err);
> +		return err;
> +	}
> +
> +	err = reset_control_deassert(port->mgmt_sticky_rst);
> +	if (err) {
> +		dev_err(port->dev, "deassert mgmt_sticky_rst err %d\n", err);
> +		return err;
> +	}
> +
> +	err = reset_control_deassert(port->pipe_rst);
> +	if (err) {
> +		dev_err(port->dev, "deassert pipe_rst err %d\n", err);
> +		return err;
> +	}
> +
> +	/* Enable Gen1 training */
> +	pcie_write(port,
> +		   HIWORD_UPDATE(PCIE_CLIENT_LINK_TRAIN_ENABLE,
> +				 PCIE_CLIENT_LINK_TRAIN_MASK,
> +				 PCIE_CLIENT_LINK_TRAIN_SHIFT),
> +		   PCIE_CLIENT_BASE);
> +
> +	gpiod_set_value(port->ep_gpio, 1);
> +
> +	/* 500ms timeout value should be enough for Gen1/2 training */
> +	timeout = jiffies + msecs_to_jiffies(500);
> +
> +	for (;;) {
> +		status = pcie_read(port, PCIE_CLIENT_BASIC_STATUS1);
> +		if (((status >> PCIE_CLIENT_LINK_STATUS_SHIFT) &
> +		      PCIE_CLIENT_LINK_STATUS_MASK) ==
> +		      PCIE_CLIENT_LINK_STATUS_UP) {
> +			dev_dbg(port->dev, "PCIe link training gen1 pass!\n");
> +			break;
> +		}
> +
> +		msleep(20);
> +
> +		if (!time_before(jiffies, timeout)) {
> +			err = -ETIMEDOUT;
> +			break;
> +		}
> +
> +	}
> +
> +	/* Double check gen1 training */
> +	if (err) {
> +		status = pcie_read(port, PCIE_CLIENT_BASIC_STATUS1);
> +		err = (((status >> PCIE_CLIENT_LINK_STATUS_SHIFT) &
> +			PCIE_CLIENT_LINK_STATUS_MASK) ==
> +			PCIE_CLIENT_LINK_STATUS_UP) ? 0 : -ETIMEDOUT;
> +		if (err) {
> +			dev_err(port->dev, "PCIe link training gen1 timeout!\n");
> +			return err;
> +		}
> +	}
> +
> +	/*
> +	 * Enable retrain for gen2. This should be configured only after
> +	 * gen1 finished.
> +	 */
> +	status = pcie_read(port,
> +			   PCIE_RC_CONFIG_LCS + PCIE_RC_CONFIG_BASE);
> +	status |= PCIE_CORE_LCSR_RETRAIN_LINK;
> +	pcie_write(port, status,
> +		   PCIE_RC_CONFIG_LCS + PCIE_RC_CONFIG_BASE);
> +
> +	timeout = jiffies + msecs_to_jiffies(500);
> +	for (;;) {
> +		status = pcie_read(port, PCIE_CORE_CTRL_MGMT_BASE);
> +		if (((status >> PCIE_CORE_PL_CONF_SPEED_SHIFT) &
> +		     PCIE_CORE_PL_CONF_SPEED_MASK) ==
> +		     PCIE_CORE_PL_CONF_SPEED_5G) {
> +			dev_dbg(port->dev, "PCIe link training gen2 pass!\n");
> +			break;
> +		}
> +
> +		msleep(20);
> +
> +		if (!time_before(jiffies, timeout)) {
> +			err = -ETIMEDOUT;
> +			break;
> +		}
> +	}
> +
> +	/* Double check gen2 training */
> +	if (err) {
> +		status = pcie_read(port, PCIE_CORE_CTRL_MGMT_BASE);
> +		err = (((status >> PCIE_CORE_PL_CONF_SPEED_SHIFT) &
> +			PCIE_CORE_PL_CONF_SPEED_MASK) ==
> +			PCIE_CORE_PL_CONF_SPEED_5G) ? 0 : -ETIMEDOUT;
> +		if (err)
> +			dev_dbg(port->dev, "PCIe link training gen2 timeout, fall back to gen1!\n");
> +	}
> +
> +	/* Check the final link width from negotiated lane counter from MGMT */
> +	status = pcie_read(port, PCIE_CORE_CTRL_MGMT_BASE);
> +	status =  0x1 << ((status >> PCIE_CORE_PL_CONF_LANE_SHIFT) &
> +			   PCIE_CORE_PL_CONF_LANE_MASK);
> +	dev_dbg(port->dev, "current link width is x%d\n", status);
> +
> +	pcie_write(port, ROCKCHIP_VENDOR_ID, PCIE_RC_CONFIG_BASE);
> +	pcie_write(port, PCI_CLASS_BRIDGE_PCI << PCIE_CORE_RC_CONF_SCC_SHIFT,
> +		   PCIE_RC_CONFIG_BASE + PCIE_RC_CONFIG_RID_CCR);
> +	pcie_write(port, 0x0, PCIE_CORE_CTRL_MGMT_BASE + PCIE_RC_BAR_CONF);
> +
> +	pcie_write(port, (RC_REGION_0_ADDR_TRANS_L + RC_REGION_0_PASS_BITS),
> +		   PCIE_CORE_AXI_CONF_BASE);
> +	pcie_write(port, RC_REGION_0_ADDR_TRANS_H,
> +		   PCIE_CORE_AXI_CONF_BASE + PCIE_CORE_OB_REGION_ADDR1);
> +	pcie_write(port, 0x0080000a,
> +		   PCIE_CORE_AXI_CONF_BASE + PCIE_CORE_OB_REGION_DESC0);
> +	pcie_write(port, 0x0,
> +		   PCIE_CORE_AXI_CONF_BASE + PCIE_CORE_OB_REGION_DESC1);
> +
> +	return 0;
> +}
> +
> +static irqreturn_t rockchip_pcie_subsys_irq_handler(int irq, void *arg)
> +{
> +	struct rockchip_pcie_port *pp = arg;
> +	u32 reg;
> +	u32 sub_reg;
> +
> +	reg = pcie_read(pp, PCIE_CLIENT_INT_STATUS);
> +	if (reg & PCIE_CLIENT_INT_LOCAL) {
> +		dev_dbg(pp->dev, "local interrupt received\n");
> +		sub_reg = pcie_read(pp, PCIE_CORE_INT_STATUS);
> +		if (sub_reg & PCIE_CORE_INT_PRFPE)
> +			dev_dbg(pp->dev, "parity error detected while reading from the PNP receive FIFO RAM\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_CRFPE)
> +			dev_dbg(pp->dev, "parity error detected while reading from the Completion Receive FIFO RAM\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_RRPE)
> +			dev_dbg(pp->dev, "parity error detected while reading from replay buffer RAM\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_PRFO)
> +			dev_dbg(pp->dev, "overflow occurred in the PNP receive FIFO\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_CRFO)
> +			dev_dbg(pp->dev, "overflow occurred in the completion receive FIFO\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_RT)
> +			dev_dbg(pp->dev, "replay timer timed out\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_RTR)
> +			dev_dbg(pp->dev, "replay timer rolled over after 4 transmissions of the same TLP\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_PE)
> +			dev_dbg(pp->dev, "phy error detected on receive side\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_MTR)
> +			dev_dbg(pp->dev, "malformed TLP received from the link\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_UCR)
> +			dev_dbg(pp->dev, "malformed TLP received from the link\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_FCE)
> +			dev_dbg(pp->dev, "an error was observed in the flow control advertisements from the other side\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_CT)
> +			dev_dbg(pp->dev, "a request timed out waiting for completion\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_UTC)
> +			dev_dbg(pp->dev, "unmapped TC error\n");
> +
> +		if (sub_reg & PCIE_CORE_INT_MMVC)
> +			dev_dbg(pp->dev, "MSI mask register changes\n");
> +
> +		pcie_write(pp, sub_reg, PCIE_CORE_INT_STATUS);
> +	} else if (reg & PCIE_CLIENT_INT_PHY) {
> +		dev_dbg(pp->dev, "phy link changes\n");
> +		rockchip_pcie_clr_bw_int(pp);
> +	}
> +
> +	pcie_write(pp, reg & PCIE_CLIENT_INT_LOCAL, PCIE_CLIENT_INT_STATUS);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t rockchip_pcie_client_irq_handler(int irq, void *arg)
> +{
> +	struct rockchip_pcie_port *pp = arg;
> +	u32 reg;
> +
> +	reg = pcie_read(pp, PCIE_CLIENT_INT_STATUS);
> +	if (reg & PCIE_CLIENT_INT_LEGACY_DONE)
> +		dev_dbg(pp->dev, "legacy done interrupt received\n");
> +
> +	if (reg & PCIE_CLIENT_INT_MSG)
> +		dev_dbg(pp->dev, "message done interrupt received\n");
> +
> +	if (reg & PCIE_CLIENT_INT_HOT_RST)
> +		dev_dbg(pp->dev, "hot reset interrupt received\n");
> +
> +	if (reg & PCIE_CLIENT_INT_DPA)
> +		dev_dbg(pp->dev, "dpa interrupt received\n");
> +
> +	if (reg & PCIE_CLIENT_INT_FATAL_ERR)
> +		dev_dbg(pp->dev, "fatal error interrupt received\n");
> +
> +	if (reg & PCIE_CLIENT_INT_NFATAL_ERR)
> +		dev_dbg(pp->dev, "no fatal error interrupt received\n");
> +
> +	if (reg & PCIE_CLIENT_INT_CORR_ERR)
> +		dev_dbg(pp->dev, "correctable error interrupt received\n");
> +
> +	if (reg & PCIE_CLIENT_INT_PHY)
> +		dev_dbg(pp->dev, "phy interrupt received\n");
> +
> +	pcie_write(pp, reg & (PCIE_CLIENT_INT_LEGACY_DONE |
> +			      PCIE_CLIENT_INT_MSG | PCIE_CLIENT_INT_HOT_RST |
> +			      PCIE_CLIENT_INT_DPA | PCIE_CLIENT_INT_FATAL_ERR |
> +			      PCIE_CLIENT_INT_NFATAL_ERR |
> +			      PCIE_CLIENT_INT_CORR_ERR),
> +			      PCIE_CLIENT_INT_STATUS |
> +			      PCIE_CLIENT_INT_PHY);
> +	return IRQ_HANDLED;
> +}
> +
> +static void rockchip_pcie_legacy_int_handler(struct irq_desc *desc)
> +{
> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> +	struct rockchip_pcie_port *port;
> +	u32 reg;
> +	u32 hwirq;
> +	u32 virq;
> +
> +	chained_irq_enter(chip, desc);
> +	port = irq_desc_get_handler_data(desc);
> +
> +	reg = pcie_read(port, PCIE_CLIENT_INT_STATUS);
> +	reg = (reg & ROCKCHIP_PCIE_RPIFR1_INTR_MASK) >>
> +	       ROCKCHIP_PCIE_RPIFR1_INTR_SHIFT;
> +
> +	while (reg) {
> +		hwirq = ffs(reg) - 1;
> +		reg &= ~BIT(hwirq);
> +
> +		virq = irq_find_mapping(port->irq_domain, hwirq);
> +		if (virq)
> +			generic_handle_irq(virq);
> +		else
> +			dev_err(port->dev, "unexpected IRQ, INT%d\n", hwirq);
> +	}
> +
> +	chained_irq_exit(chip, desc);
> +}
> +
> +
> +/**
> + * rockchip_pcie_parse_dt - Parse Device tree

s/Device tree/Device Tree/

> + * @port: PCIe port information
> + *
> + * Return: '0' on success and error value on failure
> + */
> +static int rockchip_pcie_parse_dt(struct rockchip_pcie_port *port)
> +{
> +	struct device *dev = port->dev;
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct device_node *node = dev->of_node;
> +	struct resource *regs;
> +	int irq;
> +	int err;
> +
> +	regs = platform_get_resource_byname(pdev,
> +					    IORESOURCE_MEM,
> +					    "axi-base");
> +	if (!regs) {
> +		dev_err(dev, "missing axi-base property\n");
> +		return -ENODEV;
> +	}
> +
> +	port->reg_base = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(port->reg_base))
> +		return PTR_ERR(port->reg_base);
> +
> +	regs = platform_get_resource_byname(pdev,
> +					    IORESOURCE_MEM,
> +					    "apb-base");
> +	if (!regs) {
> +		dev_err(dev, "missing apb-base property\n");
> +		return -ENODEV;
> +	}
> +
> +	port->apb_base = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(port->apb_base))
> +		return PTR_ERR(port->apb_base);
> +
> +	port->phy = devm_phy_get(dev, "pcie-phy");
> +	if (IS_ERR(port->phy)) {
> +		if (PTR_ERR(port->phy) != -EPROBE_DEFER)
> +			dev_err(dev, "Missing phy\n");
> +		return PTR_ERR(port->phy);
> +	}
> +
> +	port->lanes = 1;
> +	err = of_property_read_u32(node, "num-lanes", &port->lanes);
> +	if (!err && ((port->lanes == 0) ||
> +		     (port->lanes == 3) ||
> +		     (port->lanes > 4))) {
> +		dev_warn(dev, "invalid num-lanes, default use one lane\n");
> +		port->lanes = 1;
> +	}
> +
> +	port->core_rst = devm_reset_control_get(dev, "core");
> +	if (IS_ERR(port->core_rst)) {
> +		if (PTR_ERR(port->core_rst) != -EPROBE_DEFER)
> +			dev_err(dev, "missing core rst property in node\n");
> +		return PTR_ERR(port->core_rst);
> +	}
> +
> +	port->mgmt_rst = devm_reset_control_get(dev, "mgmt");
> +	if (IS_ERR(port->mgmt_rst)) {
> +		if (PTR_ERR(port->mgmt_rst) != -EPROBE_DEFER)
> +			dev_err(dev, "missing mgmt rst property in node\n");
> +		return PTR_ERR(port->mgmt_rst);
> +	}
> +
> +	port->mgmt_sticky_rst = devm_reset_control_get(dev, "mgmt-sticky");
> +	if (IS_ERR(port->mgmt_sticky_rst)) {
> +		if (PTR_ERR(port->mgmt_sticky_rst) != -EPROBE_DEFER)
> +			dev_err(dev, "missing mgmt-sticky rst property in node\n");
> +		return PTR_ERR(port->mgmt_sticky_rst);
> +	}
> +
> +	port->pipe_rst = devm_reset_control_get(dev, "pipe");
> +	if (IS_ERR(port->pipe_rst)) {
> +		if (PTR_ERR(port->pipe_rst) != -EPROBE_DEFER)
> +			dev_err(dev, "missing pipe rst property in node\n");
> +		return PTR_ERR(port->pipe_rst);
> +	}
> +
> +	port->ep_gpio = devm_gpiod_get(dev, "ep", GPIOD_OUT_HIGH);
> +	if (IS_ERR(port->ep_gpio)) {
> +		dev_err(dev, "missing ep-gpios property in node\n");
> +		return PTR_ERR(port->ep_gpio);
> +	}
> +
> +	port->aclk_pcie = devm_clk_get(dev, "aclk");
> +	if (IS_ERR(port->aclk_pcie)) {
> +		dev_err(dev, "aclk clock not found\n");
> +		return PTR_ERR(port->aclk_pcie);
> +	}
> +
> +	port->aclk_perf_pcie = devm_clk_get(dev, "aclk-perf");
> +	if (IS_ERR(port->aclk_perf_pcie)) {
> +		dev_err(dev, "aclk_perf clock not found\n");
> +		return PTR_ERR(port->aclk_perf_pcie);
> +	}
> +
> +	port->hclk_pcie = devm_clk_get(dev, "hclk");
> +	if (IS_ERR(port->hclk_pcie)) {
> +		dev_err(dev, "hclk clock not found\n");
> +		return PTR_ERR(port->hclk_pcie);
> +	}
> +
> +	port->clk_pcie_pm = devm_clk_get(dev, "pm");
> +	if (IS_ERR(port->clk_pcie_pm)) {
> +		dev_err(dev, "pm clock not found\n");
> +		return PTR_ERR(port->clk_pcie_pm);
> +	}
> +
> +	irq = platform_get_irq_byname(pdev, "sys");
> +	if (irq < 0) {
> +		dev_err(dev, "missing sys IRQ resource\n");
> +		return -EINVAL;
> +	}
> +
> +	err = devm_request_irq(dev, irq, rockchip_pcie_subsys_irq_handler,
> +			       IRQF_SHARED, "pcie-sys", port);
> +	if (err) {
> +		dev_err(dev, "failed to request pcie subsystem IRQ\n");
> +		return err;
> +	}
> +
> +	irq = platform_get_irq_byname(pdev, "legacy");
> +	if (irq < 0) {
> +		dev_err(dev, "missing legacy IRQ resource\n");
> +		return -EINVAL;
> +	}
> +
> +	irq_set_chained_handler_and_data(irq,
> +					 rockchip_pcie_legacy_int_handler,
> +					 port);
> +
> +	irq = platform_get_irq_byname(pdev, "client");
> +	if (irq < 0) {
> +		dev_err(dev, "missing client IRQ resource\n");
> +		return -EINVAL;
> +	}
> +
> +	err = devm_request_irq(dev, irq, rockchip_pcie_client_irq_handler,
> +			       IRQF_SHARED, "pcie-client", port);
> +	if (err) {
> +		dev_err(dev, "failed to request pcie client IRQ\n");

"PCIe"

> +		return err;
> +	}
> +
> +	port->vpcie3v3 = devm_regulator_get_optional(dev, "vpcie3v3");
> +	if (IS_ERR(port->vpcie3v3)) {
> +		if (PTR_ERR(port->vpcie3v3) == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;
> +		dev_info(dev, "no vpcie3v3 regulator found\n");
> +	}
> +
> +	port->vpcie1v8 = devm_regulator_get_optional(dev, "vpcie1v8");
> +	if (IS_ERR(port->vpcie1v8)) {
> +		if (PTR_ERR(port->vpcie1v8) == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;
> +		dev_info(dev, "no vpcie1v8 regulator found\n");
> +	}
> +
> +	port->vpcie0v9 = devm_regulator_get_optional(dev, "vpcie0v9");
> +	if (IS_ERR(port->vpcie0v9)) {
> +		if (PTR_ERR(port->vpcie0v9) == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;
> +		dev_info(dev, "no vpcie0v9 regulator found\n");
> +	}
> +
> +	return 0;
> +}
> +
> +static int rockchip_pcie_set_vpcie(struct rockchip_pcie_port *port)
> +{
> +	int err;
> +
> +	if (!IS_ERR(port->vpcie3v3)) {
> +		err = regulator_enable(port->vpcie3v3);
> +		if (err) {
> +			dev_err(port->dev, "Fail to enable vpcie3v3 regulator.\n");

s/Fail/fail/ here and similar cases below.

> +			goto err_out;
> +		}
> +	}
> +
> +	if (!IS_ERR(port->vpcie1v8)) {
> +		err = regulator_enable(port->vpcie1v8);
> +		if (err) {
> +			dev_err(port->dev, "Fail to enable vpcie1v8 regulator.\n");
> +			goto err_disable_3v3;
> +		}
> +	}
> +
> +	if (!IS_ERR(port->vpcie0v9)) {
> +		err = regulator_enable(port->vpcie0v9);
> +		if (err) {
> +			dev_err(port->dev, "Fail to enable vpcie0v9 regulator.\n");
> +			goto err_disable_1v8;
> +		}
> +	}
> +
> +	return 0;
> +
> +err_disable_1v8:
> +	if (!IS_ERR(port->vpcie1v8))
> +		regulator_disable(port->vpcie1v8);
> +err_disable_3v3:
> +	if (!IS_ERR(port->vpcie3v3))
> +		regulator_disable(port->vpcie3v3);
> +err_out:
> +	return err;
> +}
> +
> +static void rockchip_pcie_enable_interrupts(struct rockchip_pcie_port *port)
> +{
> +	pcie_write(port, (PCIE_CLIENT_INT_CLI << 16) &
> +		   (~PCIE_CLIENT_INT_CLI), PCIE_CLIENT_INT_MASK);
> +	pcie_write(port, (u32)(~PCIE_CORE_INT), PCIE_CORE_INT_MASK);
> +
> +	rockchip_pcie_enable_bw_int(port);
> +}
> +
> +static int rockchip_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
> +				  irq_hw_number_t hwirq)
> +{
> +	irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
> +	irq_set_chip_data(irq, domain->host_data);
> +
> +	return 0;
> +}
> +
> +static const struct irq_domain_ops intx_domain_ops = {
> +	.map = rockchip_pcie_intx_map,
> +};
> +
> +static int rockchip_pcie_init_irq_domain(struct rockchip_pcie_port *pp)
> +{
> +	struct device *dev = pp->dev;
> +	struct device_node *intc = of_get_next_child(dev->of_node, NULL);
> +
> +	if (!intc) {
> +		dev_err(dev, "Missing child interrupt-controller node\n");
> +		return -EINVAL;
> +	}
> +
> +	pp->irq_domain = irq_domain_add_linear(intc, 4, &intx_domain_ops, pp);
> +	if (!pp->irq_domain) {
> +		dev_err(dev, "Failed to get a INTx IRQ domain\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int rockchip_pcie_prog_ob_atu(struct rockchip_pcie_port *pp,
> +				     int region_no,
> +				     int type, u8 num_pass_bits,
> +				     u32 lower_addr, u32 upper_addr)
> +{
> +	u32 ob_addr_0;
> +	u32 ob_addr_1;
> +	u32 ob_desc_0;
> +	void __iomem *aw_base;
> +
> +	if (region_no >= MAX_AXI_WRAPPER_REGION_NUM)
> +		return -EINVAL;
> +	if ((num_pass_bits + 1) < 8)
> +		return -EINVAL;
> +	if (num_pass_bits > 63)
> +		return -EINVAL;
> +	if (region_no == 0) {
> +		if (AXI_REGION_0_SIZE < (2ULL << num_pass_bits))
> +		return -EINVAL;
> +	}
> +	if (region_no != 0) {
> +		if (AXI_REGION_SIZE < (2ULL << num_pass_bits))
> +		return -EINVAL;

Misleading indentation.

> +	}

Add a blank line between all the error checking and the meat of the
function.  Also below in the corresponding ib_atu code.

> +	aw_base = pp->apb_base + PCIE_CORE_AXI_CONF_BASE;
> +	aw_base += (region_no << OB_REG_SIZE_SHIFT);
> +
> +	ob_addr_0 = num_pass_bits & PCIE_CORE_OB_REGION_ADDR0_NUM_BITS;
> +	ob_addr_0 |= lower_addr & PCIE_CORE_OB_REGION_ADDR0_LO_ADDR;
> +	ob_addr_1 = upper_addr;
> +	ob_desc_0 = (1 << 23 | type);
> +
> +	writel(ob_addr_0, aw_base);
> +	writel(ob_addr_1, aw_base + PCIE_CORE_OB_REGION_ADDR1);
> +	writel(ob_desc_0, aw_base + PCIE_CORE_OB_REGION_DESC0);
> +	writel(0, aw_base + PCIE_CORE_OB_REGION_DESC1);
> +
> +	return 0;
> +}
> +
> +static int rockchip_pcie_prog_ib_atu(struct rockchip_pcie_port *pp,
> +				     int region_no,
> +				     u8 num_pass_bits,
> +				     u32 lower_addr,
> +				     u32 upper_addr)
> +{
> +	u32 ib_addr_0;
> +	u32 ib_addr_1;
> +	void __iomem *aw_base;
> +
> +	if (!pp)
> +		return -EINVAL;

Remove this test here, too, same as in the ob_atu path.

> +	if (region_no > MAX_AXI_IB_ROOTPORT_REGION_NUM)
> +		return -EINVAL;
> +	if ((num_pass_bits + 1) < MIN_AXI_ADDR_BITS_PASSED)
> +		return -EINVAL;
> +	if (num_pass_bits > 63)
> +		return -EINVAL;
> +	aw_base = pp->apb_base + PCIE_CORE_AXI_INBOUND_BASE;
> +	aw_base += (region_no << IB_ROOT_PORT_REG_SIZE_SHIFT);
> +
> +	ib_addr_0 = num_pass_bits & PCIE_CORE_IB_REGION_ADDR0_NUM_BITS;
> +	ib_addr_0 |= (lower_addr << 8) & PCIE_CORE_IB_REGION_ADDR0_LO_ADDR;
> +	ib_addr_1 = upper_addr;
> +
> +	writel(ib_addr_0, aw_base);
> +	writel(ib_addr_1, aw_base + PCIE_RP_IB_ADDR_TRANS);
> +
> +	return 0;
> +}
> +
> +static int rockchip_pcie_probe(struct platform_device *pdev)
> +{
> +	struct rockchip_pcie_port *port;
> +	struct device *dev = &pdev->dev;
> +	struct pci_bus *bus, *child;
> +	struct resource_entry *win;
> +	resource_size_t io_base;
> +	struct resource	*busn;

Removing the initialization here means "busn" may be used
uninitialized below if the DT doesn't include an IORESOURCE_BUS item.
That's why I didn't suggest removing the initialization from "busn".

I didn't check all these variables again, so there may be others that
actually need the initialization.  Please check them all yourself.

> +	struct resource	*mem;
> +	struct resource	*io;
> +	phys_addr_t io_bus_addr;
> +	u32 io_size;
> +	phys_addr_t mem_bus_addr;
> +	u32 mem_size;
> +	int reg_no;
> +	int err;
> +	int offset;
> +
> +	LIST_HEAD(res);
> +
> +	if (!dev->of_node)
> +		return -ENODEV;
> +
> +	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> +	if (!port)
> +		return -ENOMEM;
> +
> +	port->dev = dev;
> +
> +	err = rockchip_pcie_parse_dt(port);
> +	if (err)
> +		return err;
> +
> +	err = clk_prepare_enable(port->aclk_pcie);
> +	if (err) {
> +		dev_err(dev, "Unable to enable aclk_pcie clock.\n");
> +		goto err_aclk_pcie;
> +	}
> +
> +	err = clk_prepare_enable(port->aclk_perf_pcie);
> +	if (err) {
> +		dev_err(dev, "Unable to enable aclk_perf_pcie clock.\n");
> +		goto err_aclk_perf_pcie;
> +	}
> +
> +	err = clk_prepare_enable(port->hclk_pcie);
> +	if (err) {
> +		dev_err(dev, "Unable to enable hclk_pcie clock.\n");
> +		goto err_hclk_pcie;
> +	}
> +
> +	err = clk_prepare_enable(port->clk_pcie_pm);
> +	if (err) {
> +		dev_err(dev, "Unable to enable hclk_pcie clock.\n");
> +		goto err_pcie_pm;
> +	}
> +
> +	err = rockchip_pcie_set_vpcie(port);
> +	if (err) {
> +		dev_err(port->dev, "Fail to set vpcie regulator.\n");
> +		goto err_set_vpcie;
> +	}
> +
> +	err = rockchip_pcie_init_port(port);
> +	if (err)
> +		goto err_vpcie;
> +
> +	platform_set_drvdata(pdev, port);
> +
> +	rockchip_pcie_enable_interrupts(port);
> +
> +	err = rockchip_pcie_init_irq_domain(port);
> +	if (err < 0)
> +		goto err_vpcie;
> +
> +	err = of_pci_get_host_bridge_resources(dev->of_node, 0, 0xff,
> +					       &res, &io_base);
> +	if (err)
> +		goto err_vpcie;
> +
> +	err = devm_request_pci_bus_resources(dev, &res);
> +	if (err)
> +		goto err_vpcie;
> +
> +	/* Get the I/O and memory ranges from DT */
> +	resource_list_for_each_entry(win, &res) {
> +		switch (resource_type(win->res)) {
> +		case IORESOURCE_IO:
> +			io = win->res;
> +			io->name = "I/O";
> +			io_size = resource_size(io);
> +			io_bus_addr = io->start - win->offset;
> +			err = pci_remap_iospace(io, io_base);
> +			if (err) {
> +				dev_warn(port->dev, "error %d: failed to map resource %pR\n",
> +					 err, io);
> +				continue;
> +			}
> +			break;
> +		case IORESOURCE_MEM:
> +			mem = win->res;
> +			mem->name = "MEM";
> +			mem_size = resource_size(mem);
> +			mem_bus_addr = mem->start - win->offset;
> +			break;
> +		case IORESOURCE_BUS:
> +			busn = win->res;
> +			break;
> +		default:
> +			continue;
> +		}
> +	}
> +
> +	if (mem_size)
> +		for (reg_no = 0; reg_no < (mem_size >> 20); reg_no++) {
> +			err = rockchip_pcie_prog_ob_atu(port, reg_no + 1,
> +							AXI_WRAPPER_MEM_WRITE,
> +							20 - 1,
> +							mem_bus_addr +
> +							(reg_no << 20),
> +							0);
> +			if (err) {
> +				dev_err(dev, "Program RC mem outbound ATU failed\n");
> +				goto err_vpcie;
> +			}
> +		}
> +
> +	err = rockchip_pcie_prog_ib_atu(port, 2, 32 - 1, 0x0, 0);
> +	if (err) {
> +		dev_err(dev, "Program RC mem inbound ATU failed\n");
> +		goto err_vpcie;
> +	}
> +
> +	offset = mem_size >> 20;
> +
> +	if (io_size)
> +		for (reg_no = 0; reg_no < (io_size >> 20); reg_no++) {
> +			err = rockchip_pcie_prog_ob_atu(port,
> +							reg_no + 1 + offset,
> +							AXI_WRAPPER_IO_WRITE,
> +							20 - 1,
> +							io_bus_addr +
> +							(reg_no << 20),
> +							0);
> +			if (err) {
> +				dev_err(dev, "Program RC io outbound ATU failed\n");
> +				goto err_vpcie;
> +			}
> +		}
> +
> +	if (busn)
> +		port->root_bus_nr = busn->start;
> +
> +	bus = pci_scan_root_bus(&pdev->dev, 0,
> +				&rockchip_pcie_ops, port, &res);

General practice is to fill the line with as much as will fit in 80
columns, then wrap.  It looks like "&rockchip_pcie_ops" would fit on
the previous line.  Actually, I think *everything* fits.

> +
> +	if (!bus) {
> +		err = -ENOMEM;
> +		goto err_vpcie;
> +	}
> +
> +	pci_bus_size_bridges(bus);
> +	pci_bus_assign_resources(bus);
> +	list_for_each_entry(child, &bus->children, node)
> +		pcie_bus_configure_settings(child);
> +
> +	pci_bus_add_devices(bus);
> +
> +	dev_warn(dev, "only 32-bit config accesses supported; smaller writes may corrupt adjacent RW1C fields\n");
> +
> +	return err;
> +
> +err_vpcie:
> +	if (!IS_ERR(port->vpcie3v3))
> +		regulator_disable(port->vpcie3v3);
> +	if (!IS_ERR(port->vpcie1v8))
> +		regulator_disable(port->vpcie1v8);
> +	if (!IS_ERR(port->vpcie0v9))
> +		regulator_disable(port->vpcie0v9);
> +err_set_vpcie:
> +	clk_disable_unprepare(port->clk_pcie_pm);
> +err_pcie_pm:
> +	clk_disable_unprepare(port->hclk_pcie);
> +err_hclk_pcie:
> +	clk_disable_unprepare(port->aclk_perf_pcie);
> +err_aclk_perf_pcie:
> +	clk_disable_unprepare(port->aclk_pcie);
> +err_aclk_pcie:
> +	return err;
> +}
> +
> +static const struct of_device_id rockchip_pcie_of_match[] = {
> +	{ .compatible = "rockchip,rk3399-pcie", },
> +	{}
> +};
> +
> +static struct platform_driver rockchip_pcie_driver = {
> +	.driver = {
> +		.name = "rockchip-pcie",
> +		.of_match_table = rockchip_pcie_of_match,
> +	},
> +	.probe = rockchip_pcie_probe,
> +
> +};
> +builtin_platform_driver(rockchip_pcie_driver);
> +

Spurious blank line here.