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From:   Emil Renner Berthing <emil.renner.berthing@canonical.com>
In-Reply-To: <20230915102243.59775-19-minda.chen@starfivetech.com>
References: <20230915102243.59775-1-minda.chen@starfivetech.com> <20230915102243.59775-19-minda.chen@starfivetech.com>
Mime-Version: 1.0
Date:   Sun, 17 Sep 2023 15:13:04 -0700
Message-ID: <CAJM55Z_V7Zyni=hj8RLYb_Q0AbJ+8XNo6ABq2-=2_jD0KO1nFQ@mail.gmail.com>
Subject: Re: [PATCH v6 18/19] PCI: starfive: Add JH7110 PCIe controller
To:     Minda Chen <minda.chen@starfivetech.com>,
        Daire McNamara <daire.mcnamara@microchip.com>,
        Conor Dooley <conor@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= <kw@linux.com>,
        Emil Renner Berthing <emil.renner.berthing@canonical.com>
Cc:     devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-riscv@lists.infradead.org, linux-pci@vger.kernel.org,
        =?UTF-8?Q?Pali_Roh=C3=A1r?= <pali@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Mason Huo <mason.huo@starfivetech.com>,
        Leyfoon Tan <leyfoon.tan@starfivetech.com>,
        Kevin Xie <kevin.xie@starfivetech.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Minda Chen wrote:
> Add StarFive JH7110 SoC PCIe controller platform
> driver codes, and add host init/deinit to pcie-plda-host.c
>
> Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
> Co-developed-by: Kevin Xie <kevin.xie@starfivetech.com>
> Reviewed-by: Mason Huo <mason.huo@starfivetech.com>
> ---
>  MAINTAINERS                                  |   7 +
>  drivers/pci/controller/plda/Kconfig          |  12 +
>  drivers/pci/controller/plda/Makefile         |   1 +
>  drivers/pci/controller/plda/pcie-plda-host.c | 121 ++++-
>  drivers/pci/controller/plda/pcie-plda.h      |  91 +++-
>  drivers/pci/controller/plda/pcie-starfive.c  | 461 +++++++++++++++++++
>  6 files changed, 688 insertions(+), 5 deletions(-)
>  create mode 100644 drivers/pci/controller/plda/pcie-starfive.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ebdb65e195ee..4632cd411a3d 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16679,6 +16679,13 @@ S:	Maintained
>  F:	Documentation/devicetree/bindings/pci/socionext,uniphier-pcie*
>  F:	drivers/pci/controller/dwc/pcie-uniphier*
>
> +PCIE DRIVER FOR STARFIVE JH71x0
> +M:	Kevin Xie <kevin.xie@starfivetech.com>
> +L:	linux-pci@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/pci/starfive*
> +F:	drivers/pci/controller/plda/pcie-starfive.c
> +
>  PCIE DRIVER FOR ST SPEAR13XX
>  M:	Pratyush Anand <pratyush.anand@gmail.com>
>  L:	linux-pci@vger.kernel.org
> diff --git a/drivers/pci/controller/plda/Kconfig b/drivers/pci/controller/plda/Kconfig
> index e54a82ee94f5..8de661730aa5 100644
> --- a/drivers/pci/controller/plda/Kconfig
> +++ b/drivers/pci/controller/plda/Kconfig
> @@ -15,4 +15,16 @@ config PCIE_MICROCHIP_HOST
>  	  Say Y here if you want kernel to support the Microchip AXI PCIe
>  	  Host Bridge driver.
>
> +config PCIE_STARFIVE_HOST
> +	tristate "StarFive PCIe host controller"
> +	depends on OF && PCI_MSI
> +	select PCIE_PLDA_HOST
> +	help
> +	  Say Y here if you want to support the StarFive PCIe controller
> +	  in host mode. StarFive PCIe controller uses PLDA PCIe
> +	  core.
> +	  If you choose to build this driver as module it will
> +	  be dynamically linked and module will be called
> +	  pcie-starfive.ko
> +
>  endmenu
> diff --git a/drivers/pci/controller/plda/Makefile b/drivers/pci/controller/plda/Makefile
> index 4340ab007f44..0ac6851bed48 100644
> --- a/drivers/pci/controller/plda/Makefile
> +++ b/drivers/pci/controller/plda/Makefile
> @@ -1,3 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-$(CONFIG_PCIE_PLDA_HOST) += pcie-plda-host.o
>  obj-$(CONFIG_PCIE_MICROCHIP_HOST) += pcie-microchip-host.o
> +obj-$(CONFIG_PCIE_STARFIVE_HOST) += pcie-starfive.o
> diff --git a/drivers/pci/controller/plda/pcie-plda-host.c b/drivers/pci/controller/plda/pcie-plda-host.c
> index 26e6cfd2eaba..8b32df477ad8 100644
> --- a/drivers/pci/controller/plda/pcie-plda-host.c
> +++ b/drivers/pci/controller/plda/pcie-plda-host.c
> @@ -20,6 +20,15 @@
>
>  #include "pcie-plda.h"
>
> +void __iomem *plda_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
> +				int where)
> +{
> +	struct plda_pcie_rp *pcie = bus->sysdata;
> +
> +	return pcie->config_base + PCIE_ECAM_OFFSET(bus->number, devfn, where);
> +}
> +EXPORT_SYMBOL_GPL(plda_pcie_map_bus);
> +
>  static void plda_handle_msi(struct irq_desc *desc)
>  {
>  	struct plda_pcie_rp *port = irq_desc_get_handler_data(desc);
> @@ -370,6 +379,12 @@ static const struct plda_event_ops plda_event_ops = {
>  	.get_events = plda_get_events,
>  };
>
> +static const struct plda_event plda_default_event = {
> +	.event_ops		= &plda_event_ops,
> +	.intx_event		= EVENT_PM_MSI_INT_INTX,
> +	.msi_event		= EVENT_PM_MSI_INT_MSI
> +};
> +
>  static int plda_pcie_init_irq_domains(struct plda_pcie_rp *port,
>  				      const struct irq_domain_ops *ops)
>  {
> @@ -416,7 +431,6 @@ int plda_init_interrupts(struct platform_device *pdev,
>  			 const struct plda_event *event)
>  {
>  	struct device *dev = &pdev->dev;
> -	int irq;
>  	int i, intx_irq, msi_irq, event_irq;
>  	int ret;
>  	const struct irq_domain_ops *irq_dom_ops;
> @@ -434,8 +448,8 @@ int plda_init_interrupts(struct platform_device *pdev,
>  		return ret;
>  	}
>
> -	irq = platform_get_irq(pdev, 0);
> -	if (irq < 0)
> +	port->irq = platform_get_irq(pdev, 0);
> +	if (port->irq < 0)
>  		return -ENODEV;

Here you're dropping the local variable irq and just use port->irq directly..

>
>  	port->event_ops = event->event_ops;
> @@ -465,6 +479,7 @@ int plda_init_interrupts(struct platform_device *pdev,
>  		dev_err(dev, "failed to map INTx interrupt\n");
>  		return -ENXIO;
>  	}
> +	port->intx_irq = intx_irq;

..but for intx_irq..

>
>  	/* Plug the INTx chained handler */
>  	irq_set_chained_handler_and_data(intx_irq, plda_handle_intx, port);
> @@ -473,12 +488,13 @@ int plda_init_interrupts(struct platform_device *pdev,
>  				     event->msi_event);
>  	if (!msi_irq)
>  		return -ENXIO;
> +	port->msi_irq = msi_irq;

..and msi_irq you're keeping the local variable. I think you should drop
the local variables here too, or at least do the same for all of them.

>
>  	/* Plug the MSI chained handler */
>  	irq_set_chained_handler_and_data(msi_irq, plda_handle_msi, port);
>
>  	/* Plug the main event chained handler */
> -	irq_set_chained_handler_and_data(irq, plda_handle_event, port);
> +	irq_set_chained_handler_and_data(port->irq, plda_handle_event, port);
>
>  	return 0;
>  }
> @@ -544,3 +560,100 @@ int plda_pcie_setup_iomems(struct pci_host_bridge *bridge,
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(plda_pcie_setup_iomems);
> +
> +static void plda_pcie_irq_domain_deinit(struct plda_pcie_rp *pcie)
> +{
> +	irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
> +	irq_set_chained_handler_and_data(pcie->msi_irq, NULL, NULL);
> +	irq_set_chained_handler_and_data(pcie->intx_irq, NULL, NULL);
> +
> +	irq_domain_remove(pcie->msi.msi_domain);
> +	irq_domain_remove(pcie->msi.dev_domain);
> +
> +	irq_domain_remove(pcie->intx_domain);
> +	irq_domain_remove(pcie->event_domain);
> +}
> +
> +int plda_pcie_host_init(struct plda_pcie_rp *port, struct pci_ops *ops)
> +{
> +	struct resource *cfg_res;
> +	struct device *dev = port->dev;
> +	int ret;
> +	struct pci_host_bridge *bridge;
> +	struct platform_device *pdev = to_platform_device(dev);

This looks weird. Please order initialized variables first and maybe even do
reverse christmas tree order. Eg. longeist lines first.

> +
> +	port->bridge_addr =
> +		devm_platform_ioremap_resource_byname(pdev, "apb");
> +
> +	if (IS_ERR(port->bridge_addr))
> +		return dev_err_probe(dev, PTR_ERR(port->bridge_addr),
> +				     "failed to map reg memory\n");
> +
> +	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
> +	if (!cfg_res)
> +		return dev_err_probe(dev, -ENODEV,
> +				     "failed to get config memory\n");
> +
> +	port->config_base = devm_ioremap_resource(dev, cfg_res);
> +	if (IS_ERR(port->config_base))
> +		return dev_err_probe(dev, PTR_ERR(port->config_base),
> +				     "failed to map config memory\n");
> +
> +	port->phy = devm_phy_optional_get(dev, NULL);
> +	if (IS_ERR(port->phy))
> +		return dev_err_probe(dev, PTR_ERR(port->phy),
> +				     "failed to get pcie phy\n");
> +
> +	bridge = devm_pci_alloc_host_bridge(dev, 0);
> +	if (!bridge)
> +		return dev_err_probe(dev, -ENOMEM,
> +				     "failed to alloc bridge\n");
> +
> +	if (port->host_ops && port->host_ops->host_init) {
> +		ret = port->host_ops->host_init(port);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	port->bridge = bridge;
> +	plda_pcie_setup_window(port->bridge_addr, 0, cfg_res->start, 0,
> +			       resource_size(cfg_res));
> +	plda_pcie_setup_iomems(bridge, port);
> +	plda_set_default_msi(&port->msi);
> +	ret = plda_init_interrupts(pdev, port, &plda_default_event);
> +	if (ret)
> +		goto err_host;
> +
> +	/* Set default bus ops */
> +	bridge->ops = ops;
> +	bridge->sysdata = port;
> +
> +	ret = pci_host_probe(bridge);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to pci host probe: %d\n", ret);

I think you mean:

dev_err_probe(dev, ret, "failed to probe pci host\n");

> +		goto err_probe;
> +	}
> +
> +	return ret;
> +
> +err_probe:
> +	plda_pcie_irq_domain_deinit(port);
> +err_host:
> +	if (port->host_ops && port->host_ops->host_deinit)
> +		port->host_ops->host_deinit(port);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(plda_pcie_host_init);
> +
> +void plda_pcie_host_deinit(struct plda_pcie_rp *port)
> +{
> +	pci_stop_root_bus(port->bridge->bus);
> +	pci_remove_root_bus(port->bridge->bus);
> +
> +	plda_pcie_irq_domain_deinit(port);
> +
> +	if (port->host_ops && port->host_ops->host_deinit)
> +		port->host_ops->host_deinit(port);
> +}
> +EXPORT_SYMBOL_GPL(plda_pcie_host_deinit);
> diff --git a/drivers/pci/controller/plda/pcie-plda.h b/drivers/pci/controller/plda/pcie-plda.h
> index b7420598a326..e571047d7944 100644
> --- a/drivers/pci/controller/plda/pcie-plda.h
> +++ b/drivers/pci/controller/plda/pcie-plda.h
> @@ -6,14 +6,24 @@
>  #ifndef _PCIE_PLDA_H
>  #define _PCIE_PLDA_H
>
> +#include <linux/phy/phy.h>
> +
>  /* Number of MSI IRQs */
>  #define PLDA_MAX_NUM_MSI_IRQS			32
>
>  /* PCIe Bridge Phy Regs */
> +#define GEN_SETTINGS				0x80
> +#define  RP_ENABLE				1
> +#define PCIE_PCI_IDS_DW1			0x9c
> +#define  IDS_CLASS_CODE_SHIFT			16
>  #define PCIE_PCI_IRQ_DW0			0xa8
>  #define  MSIX_CAP_MASK				BIT(31)
>  #define  NUM_MSI_MSGS_MASK			GENMASK(6, 4)
>  #define  NUM_MSI_MSGS_SHIFT			4
> +#define PCI_MISC				0xb4
> +#define  PHY_FUNCTION_DIS			BIT(15)
> +#define PCIE_WINROM				0xfc
> +#define  PREF_MEM_WIN_64_SUPPORT		BIT(3)
>
>  #define IMASK_LOCAL				0x180
>  #define  DMA_END_ENGINE_0_MASK			0x00000000u
> @@ -64,6 +74,8 @@
>  #define ISTATUS_HOST				0x18c
>  #define IMSI_ADDR				0x190
>  #define ISTATUS_MSI				0x194
> +#define PMSG_SUPPORT_RX				0x3f0
> +#define  PMSG_LTR_SUPPORT			BIT(2)
>
>  /* PCIe Master table init defines */
>  #define ATR0_PCIE_WIN0_SRCADDR_PARAM		0x600u
> @@ -85,6 +97,8 @@
>  #define  PCIE_TX_RX_INTERFACE			0x00000000u
>  #define  PCIE_CONFIG_INTERFACE			0x00000001u
>
> +#define CONFIG_SPACE_ADDR			0x1000u
> +
>  #define ATR_ENTRY_SIZE				32
>
>  #define EVENT_A_ATR_EVT_POST_ERR		0
> @@ -134,6 +148,11 @@ struct plda_event_ops {
>  	u32 (*get_events)(struct plda_pcie_rp *pcie);
>  };
>
> +struct plda_pcie_host_ops {
> +	int (*host_init)(struct plda_pcie_rp *pcie);
> +	void (*host_deinit)(struct plda_pcie_rp *pcie);
> +};
> +
>  struct plda_msi {
>  	struct mutex lock;		/* Protect used bitmap */
>  	struct irq_domain *msi_domain;
> @@ -145,12 +164,19 @@ struct plda_msi {
>
>  struct plda_pcie_rp {
>  	struct device *dev;
> +	struct pci_host_bridge *bridge;
>  	struct irq_domain *intx_domain;
>  	struct irq_domain *event_domain;
>  	raw_spinlock_t lock;
>  	struct plda_msi msi;
>  	const struct plda_event_ops *event_ops;
> +	const struct plda_pcie_host_ops *host_ops;
> +	struct phy *phy;
>  	void __iomem *bridge_addr;
> +	void __iomem *config_base;
> +	int irq;
> +	int msi_irq;
> +	int intx_irq;
>  	int num_events;
>  };
>
> @@ -163,6 +189,7 @@ struct plda_event {
>  	int msi_event;
>  };
>
> +void __iomem *plda_pcie_map_bus(struct pci_bus *bus, unsigned int devfn, int where);
>  int plda_init_interrupts(struct platform_device *pdev,
>  			 struct plda_pcie_rp *port,
>  			 const struct plda_event *event);
> @@ -171,4 +198,66 @@ void plda_pcie_setup_window(void __iomem *bridge_base_addr, u32 index,
>  			    size_t size);
>  int plda_pcie_setup_iomems(struct pci_host_bridge *bridge,
>  			   struct plda_pcie_rp *port);
> -#endif
> +int plda_pcie_host_init(struct plda_pcie_rp *pcie, struct pci_ops *ops);
> +void plda_pcie_host_deinit(struct plda_pcie_rp *pcie);
> +
> +static inline void plda_set_default_msi(struct plda_msi *msi)
> +{
> +	msi->vector_phy = IMSI_ADDR;
> +	msi->num_vectors = PLDA_MAX_NUM_MSI_IRQS;
> +}
> +
> +static inline void plda_pcie_enable_root_port(struct plda_pcie_rp *plda)
> +{
> +	u32 value;
> +
> +	value = readl_relaxed(plda->bridge_addr + GEN_SETTINGS);
> +	value |= RP_ENABLE;
> +	writel_relaxed(value, plda->bridge_addr + GEN_SETTINGS);
> +}
> +
> +static inline void plda_pcie_set_standard_class(struct plda_pcie_rp *plda)
> +{
> +	u32 value;
> +
> +	value = readl_relaxed(plda->bridge_addr + PCIE_PCI_IDS_DW1);
> +	value &= 0xff;
> +	value |= (PCI_CLASS_BRIDGE_PCI << IDS_CLASS_CODE_SHIFT);

This looks suspicious. You're clearing the lower 8 bits, but setting
bits 16 and up. Also the parentheses are not strictly necessary.

> +	writel_relaxed(value, plda->bridge_addr + PCIE_PCI_IDS_DW1);
> +}
> +
> +static inline void plda_pcie_set_pref_win_64bit(struct plda_pcie_rp *plda)
> +{
> +	u32 value;
> +
> +	value = readl_relaxed(plda->bridge_addr + PCIE_WINROM);
> +	value |= PREF_MEM_WIN_64_SUPPORT;
> +	writel_relaxed(value, plda->bridge_addr + PCIE_WINROM);
> +}
> +
> +static inline void plda_pcie_disable_ltr(struct plda_pcie_rp *plda)
> +{
> +	u32 value;
> +
> +	value = readl_relaxed(plda->bridge_addr + PMSG_SUPPORT_RX);
> +	value &= ~PMSG_LTR_SUPPORT;
> +	writel_relaxed(value, plda->bridge_addr + PMSG_SUPPORT_RX);
> +}
> +
> +static inline void plda_pcie_disable_func(struct plda_pcie_rp *plda)
> +{
> +	u32 value;
> +
> +	value = readl_relaxed(plda->bridge_addr + PCI_MISC);
> +	value |= PHY_FUNCTION_DIS;
> +	writel_relaxed(value, plda->bridge_addr + PCI_MISC);
> +}
> +
> +static inline void plda_pcie_write_rc_bar(struct plda_pcie_rp *plda, u64 val)
> +{
> +	void __iomem *addr = plda->bridge_addr + CONFIG_SPACE_ADDR;
> +
> +	writel_relaxed(val & 0xffffffff, addr + PCI_BASE_ADDRESS_0);
> +	writel_relaxed(val >> 32, addr + PCI_BASE_ADDRESS_1);

Consider using lower_32_bits(val) and upper_32_bits(val) here.

> +}
> +#endif /* _PCIE_PLDA_H */
> diff --git a/drivers/pci/controller/plda/pcie-starfive.c b/drivers/pci/controller/plda/pcie-starfive.c
> new file mode 100644
> index 000000000000..42099fef0d7d
> --- /dev/null
> +++ b/drivers/pci/controller/plda/pcie-starfive.c
> @@ -0,0 +1,461 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * PCIe host controller driver for StarFive JH7110 Soc.
> + *
> + * Copyright (C) 2023 StarFive Technology Co., Ltd.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_pci.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +#include "../../pci.h"
> +
> +#include "pcie-plda.h"
> +
> +#define PCIE_FUNC_NUM			4
> +
> +/* system control */
> +#define STG_SYSCON_PCIE0_BASE			0x48
> +#define STG_SYSCON_PCIE1_BASE			0x1f8
> +
> +#define STG_SYSCON_ARFUNC_OFFSET		0x78
> +#define STG_SYSCON_AXI4_SLVL_ARFUNC_MASK	 GENMASK(22, 8)
> +#define STG_SYSCON_AXI4_SLVL_PHY_ARFUNC(x)	 FIELD_PREP(GENMASK(20, 17), x)
> +#define STG_SYSCON_AWFUNC_OFFSET		0x7c
> +#define STG_SYSCON_AXI4_SLVL_AWFUNC_MASK	 GENMASK(14, 0)
> +#define STG_SYSCON_AXI4_SLVL_PHY_AWFUNC(x)	 FIELD_PREP(GENMASK(12, 9), x)
> +#define STG_SYSCON_CLKREQ			 BIT(22)
> +#define STG_SYSCON_CKREF_SRC_MASK		 GENMASK(19, 18)
> +#define STG_SYSCON_RP_NEP_OFFSET		0xe8
> +#define STG_SYSCON_K_RP_NEP			 BIT(8)
> +#define STG_SYSCON_LNKSTA_OFFSET		0x170
> +#define DATA_LINK_ACTIVE			 BIT(5)
> +
> +/* Parameters for the waiting for link up routine */
> +#define LINK_WAIT_MAX_RETRIES	10
> +#define LINK_WAIT_USLEEP_MIN	90000
> +#define LINK_WAIT_USLEEP_MAX	100000
> +
> +struct starfive_jh7110_pcie {
> +	struct plda_pcie_rp plda;
> +	struct reset_control *resets;
> +	struct clk_bulk_data *clks;
> +	struct regmap *reg_syscon;
> +	struct gpio_desc *power_gpio;
> +	struct gpio_desc *reset_gpio;
> +
> +	u32 stg_arfun;
> +	u32 stg_awfun;
> +	u32 stg_rp_nep;
> +	u32 stg_lnksta;
> +
> +	int num_clks;
> +};
> +
> +/*
> + * The BAR0/1 of bridge should be hidden during enumeration to
> + * avoid the sizing and resource allocation by PCIe core.
> + */
> +static bool starfive_pcie_hide_rc_bar(struct pci_bus *bus, unsigned int  devfn,
> +				      int offset)
> +{
> +	if (pci_is_root_bus(bus) && !devfn &&
> +	    (offset == PCI_BASE_ADDRESS_0 || offset == PCI_BASE_ADDRESS_1))
> +		return true;
> +
> +	return false;
> +}
> +
> +static int starfive_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
> +				      int where, int size, u32 value)
> +{
> +	if (starfive_pcie_hide_rc_bar(bus, devfn, where))
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +
> +	return pci_generic_config_write(bus, devfn, where, size, value);
> +}
> +
> +static int starfive_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
> +				     int where, int size, u32 *value)
> +{
> +	if (starfive_pcie_hide_rc_bar(bus, devfn, where))
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +
> +	return pci_generic_config_read(bus, devfn, where, size, value);
> +}
> +
> +static int starfive_pcie_parse_dt(struct starfive_jh7110_pcie *pcie, struct device *dev)
> +{
> +	int domain_nr, stg_pcie_base;
> +
> +	pcie->num_clks = devm_clk_bulk_get_all(dev, &pcie->clks);
> +	if (pcie->num_clks < 0)
> +		return dev_err_probe(dev, -ENODEV,
> +			"failed to get pcie clocks\n");
> +
> +	pcie->resets = devm_reset_control_array_get_exclusive(dev);
> +	if (IS_ERR(pcie->resets))
> +		return dev_err_probe(dev, PTR_ERR(pcie->resets),
> +			"failed to get pcie resets");
> +
> +	pcie->reg_syscon =
> +		syscon_regmap_lookup_by_phandle(dev->of_node,
> +						"starfive,stg-syscon");
> +
> +	if (IS_ERR(pcie->reg_syscon))
> +		return dev_err_probe(dev, PTR_ERR(pcie->reg_syscon),
> +			"failed to parse starfive,stg-syscon\n");
> +
> +	domain_nr = of_get_pci_domain_nr(dev->of_node);
> +
> +	if (domain_nr < 0 || domain_nr > 1)
> +		return dev_err_probe(dev, -ENODEV,
> +			"failed to get valid pcie id\n");
> +
> +	if (domain_nr == 0)
> +		stg_pcie_base = STG_SYSCON_PCIE0_BASE;
> +	else
> +		stg_pcie_base = STG_SYSCON_PCIE1_BASE;

It seems you only need the domain_nr for the determining this offset into the
stg_syscon. Since this is already specific to the JH7110 SoC, wouldn't it be
safer to match on the 0x2b000000/0x2c000000 or 0x940000000/0x9c0000000
address of the peripheral instead?

> +
> +	pcie->stg_arfun = stg_pcie_base + STG_SYSCON_ARFUNC_OFFSET;
> +	pcie->stg_awfun = stg_pcie_base + STG_SYSCON_AWFUNC_OFFSET;
> +	pcie->stg_rp_nep = stg_pcie_base + STG_SYSCON_RP_NEP_OFFSET;
> +	pcie->stg_lnksta = stg_pcie_base + STG_SYSCON_LNKSTA_OFFSET;

These offsets are all the same for both pcie0 and pcie1 so why do you need a
variable for each? Eg. why not just

if (domain_nr == 0)
	pcie->stg_base = STG_SYSCON_PCIE0_BASE;
else
	pcie->stg_base = STG_SYSCON_PCIE1_BASE;

..and then add add those static offsets where needed?

> +
> +	pcie->reset_gpio = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_HIGH);
> +	if (IS_ERR(pcie->reset_gpio)) {
> +		dev_warn(dev, "failed to get perst-gpio\n");

Why is this a warn when you actually error out? I think you mean

return dev_err_probe(dev, PTR_ERR(pcie->reset_gpio, "failed to get
reset GPIO\n");

> +		return -EINVAL;
> +	}
> +
> +	pcie->power_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
> +	if (IS_ERR(pcie->power_gpio)) {
> +		dev_warn(dev, "failed to get power-gpio\n");
> +		return -EINVAL;

return dev_err_probe(dev, PTR_ERR(pcie->power_gpio), "failed to get
power GPIO\n");

> +	}
> +
> +	return 0;
> +}
> +
> +static struct pci_ops starfive_pcie_ops = {
> +	.map_bus	= plda_pcie_map_bus,
> +	.read           = starfive_pcie_config_read,
> +	.write          = starfive_pcie_config_write,
> +};
> +
> +static int starfive_pcie_clk_rst_init(struct starfive_jh7110_pcie *pcie)
> +{
> +	int ret;
> +	struct device *dev = pcie->plda.dev;

Again, please order initialized variables first.

> +
> +	ret = clk_bulk_prepare_enable(pcie->num_clks, pcie->clks);
> +	if (ret) {
> +		dev_err(dev, "failed to enable clocks\n");
> +		return ret;

return dev_err_probe(dev, ret, "failed to enable clocks\n");

> +	}
> +
> +	ret = reset_control_deassert(pcie->resets);
> +	if (ret) {
> +		clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
> +		dev_err(dev, "failed to resets\n");

I think you mean
return dev_err_probe(dev, ret, "failed to deassert resets\n");

> +	}
> +
> +	return ret;
> +}
> +
> +static void starfive_pcie_clk_rst_deinit(struct starfive_jh7110_pcie *pcie)
> +{
> +	reset_control_assert(pcie->resets);
> +	clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
> +}
> +
> +static bool starfive_pcie_link_up(struct plda_pcie_rp *plda)
> +{
> +	struct starfive_jh7110_pcie *pcie =
> +		container_of(plda, struct starfive_jh7110_pcie, plda);
> +	struct device *dev = pcie->plda.dev;

This is only used once below, so just use pcie->plda.dev directly there.

> +	int ret;
> +	u32 stg_reg_val;
> +
> +	ret = regmap_read(pcie->reg_syscon, pcie->stg_lnksta, &stg_reg_val);
> +	if (ret) {
> +		dev_err(dev, "failed to read link status\n");
> +		return false;
> +	}
> +
> +	if (stg_reg_val & DATA_LINK_ACTIVE)
> +		return true;
> +
> +	return false;

These last 4 lines is just "return stg_reg_val & DATA_LINK_ACTIVE;" right?

> +}
> +
> +static int starfive_pcie_host_wait_for_link(struct starfive_jh7110_pcie *pcie)
> +{
> +	struct device *dev = pcie->plda.dev;

Only used once, just inline.

> +	int retries;
> +
> +	/* Check if the link is up or not */
> +	for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
> +		if (starfive_pcie_link_up(&pcie->plda)) {
> +			dev_info(dev, "port link up\n");
> +			return 0;
> +		}
> +		usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
> +	}
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static int starfive_pcie_enable_phy(struct device *dev, struct plda_pcie_rp *pcie)
> +{
> +	int ret;
> +
> +	if (!pcie->phy)
> +		return 0;
> +
> +	ret = phy_init(pcie->phy);
> +	if (ret)
> +		return dev_err_probe(dev, ret,
> +			"failed to initialize pcie phy\n");
> +
> +	ret = phy_set_mode(pcie->phy, PHY_MODE_PCIE);
> +	if (ret) {
> +		dev_err(dev, "failed to set pcie mode\n");
> +		goto err_phy_on;
> +	}
> +
> +	ret = phy_power_on(pcie->phy);
> +	if (ret) {
> +		dev_err(dev, "failed to power on pcie phy\n");
> +		goto err_phy_on;
> +	}
> +
> +	return 0;
> +
> +err_phy_on:
> +	phy_exit(pcie->phy);
> +	return ret;
> +}
> +
> +static void starfive_pcie_disable_phy(struct plda_pcie_rp *pcie)
> +{
> +	phy_power_off(pcie->phy);
> +	phy_exit(pcie->phy);
> +}
> +
> +static void starfive_pcie_host_deinit(struct plda_pcie_rp *plda)
> +{
> +	struct starfive_jh7110_pcie *pcie =
> +		container_of(plda, struct starfive_jh7110_pcie, plda);
> +
> +	starfive_pcie_clk_rst_deinit(pcie);
> +	if (pcie->power_gpio)
> +		gpiod_set_value_cansleep(pcie->power_gpio, 0);
> +	starfive_pcie_disable_phy(plda);
> +}
> +
> +static int starfive_pcie_host_init(struct plda_pcie_rp *plda)
> +{
> +	int i;
> +	struct starfive_jh7110_pcie *pcie =
> +		container_of(plda, struct starfive_jh7110_pcie, plda);
> +	struct device *dev = plda->dev;
> +	int ret;

Weird ordering again.

> +
> +	ret = starfive_pcie_enable_phy(dev, plda);
> +	if (ret)
> +		return ret;
> +
> +	regmap_update_bits(pcie->reg_syscon, pcie->stg_rp_nep,
> +			   STG_SYSCON_K_RP_NEP, STG_SYSCON_K_RP_NEP);
> +
> +	regmap_update_bits(pcie->reg_syscon, pcie->stg_awfun,
> +			   STG_SYSCON_CKREF_SRC_MASK,
> +			   FIELD_PREP(STG_SYSCON_CKREF_SRC_MASK, 2));
> +
> +	regmap_update_bits(pcie->reg_syscon, pcie->stg_awfun,
> +			   STG_SYSCON_CLKREQ, STG_SYSCON_CLKREQ);
> +
> +	ret = starfive_pcie_clk_rst_init(pcie);
> +	if (ret)
> +		return ret;
> +
> +	if (pcie->power_gpio)
> +		gpiod_set_value_cansleep(pcie->power_gpio, 1);
> +
> +	if (pcie->reset_gpio)
> +		gpiod_set_value_cansleep(pcie->reset_gpio, 1);
> +
> +	/* Disable physical functions except #0 */
> +	for (i = 1; i < PCIE_FUNC_NUM; i++) {
> +		regmap_update_bits(pcie->reg_syscon,
> +				   pcie->stg_arfun,
> +				   STG_SYSCON_AXI4_SLVL_ARFUNC_MASK,
> +				   STG_SYSCON_AXI4_SLVL_PHY_ARFUNC(i));
> +
> +		regmap_update_bits(pcie->reg_syscon,
> +				   pcie->stg_awfun,
> +				   STG_SYSCON_AXI4_SLVL_AWFUNC_MASK,
> +				   STG_SYSCON_AXI4_SLVL_PHY_AWFUNC(i));
> +
> +		plda_pcie_disable_func(plda);
> +	}
> +
> +	regmap_update_bits(pcie->reg_syscon, pcie->stg_arfun,
> +			   STG_SYSCON_AXI4_SLVL_ARFUNC_MASK, 0);
> +	regmap_update_bits(pcie->reg_syscon, pcie->stg_awfun,
> +			   STG_SYSCON_AXI4_SLVL_AWFUNC_MASK, 0);
> +
> +	plda_pcie_enable_root_port(plda);
> +	plda_pcie_write_rc_bar(plda, 0);
> +
> +	/* PCIe PCI Standard Configuration Identification Settings. */
> +	plda_pcie_set_standard_class(plda);
> +
> +	/*
> +	 * The LTR message forwarding of PCIe Message Reception was set by core
> +	 * as default, but the forward id & addr are also need to be reset.
> +	 * If we do not disable LTR message forwarding here, or set a legal
> +	 * forwarding address, the kernel will get stuck after this driver probe.
> +	 * To workaround, disable the LTR message forwarding support on
> +	 * PCIe Message Reception.
> +	 */
> +	plda_pcie_disable_ltr(plda);
> +
> +	/* Prefetchable memory window 64-bit addressing support */
> +	plda_pcie_set_pref_win_64bit(plda);
> +
> +	/* Ensure that PERST has been asserted for at least 100 ms,
> +	 * the sleep value is T_PVPERL from PCIe CEM spec r2.0 (Table 2-4)
> +	 */
> +	msleep(100);
> +	if (pcie->reset_gpio)
> +		gpiod_set_value_cansleep(pcie->reset_gpio, 0);
> +
> +	/* As the requirement in PCIe base spec r6.0, system (<=5GT/s) must
> +	 * wait a minimum of 100 ms following exit from a conventional reset
> +	 * before sending a configuration request to the device.
> +	 */
> +	msleep(100);
> +
> +	if (starfive_pcie_host_wait_for_link(pcie))
> +		dev_info(dev, "port link down\n");
> +
> +	return ret;
> +}
> +
> +static const struct plda_pcie_host_ops sf_host_ops = {
> +	.host_init = starfive_pcie_host_init,
> +	.host_deinit = starfive_pcie_host_deinit,
> +};
> +
> +static int starfive_pcie_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct starfive_jh7110_pcie *pcie;
> +	struct plda_pcie_rp *plda;
> +	int ret;
> +
> +	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
> +	if (!pcie)
> +		return -ENOMEM;
> +
> +	plda = &pcie->plda;
> +	plda->dev = dev;
> +
> +	ret = starfive_pcie_parse_dt(pcie, dev);
> +	if (ret)
> +		return ret;
> +
> +	plda->host_ops = &sf_host_ops;
> +	plda->num_events = NUM_PLDA_EVENTS;
> +	ret = plda_pcie_host_init(&pcie->plda, &starfive_pcie_ops);
> +	if (ret)
> +		return ret;
> +
> +	pm_runtime_enable(&pdev->dev);
> +	pm_runtime_get_sync(&pdev->dev);
> +	platform_set_drvdata(pdev, pcie);
> +
> +	return 0;
> +}
> +
> +static void starfive_pcie_remove(struct platform_device *pdev)
> +{
> +	struct starfive_jh7110_pcie *pcie = platform_get_drvdata(pdev);
> +
> +	plda_pcie_host_deinit(&pcie->plda);
> +	platform_set_drvdata(pdev, NULL);
> +}
> +
> +static int starfive_pcie_suspend_noirq(struct device *dev)
> +{
> +	struct starfive_jh7110_pcie *pcie = dev_get_drvdata(dev);
> +
> +	if (!pcie)
> +		return 0;
> +
> +	clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
> +	starfive_pcie_disable_phy(&pcie->plda);
> +
> +	return 0;
> +}
> +
> +static int starfive_pcie_resume_noirq(struct device *dev)
> +{
> +	struct starfive_jh7110_pcie *pcie = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = starfive_pcie_enable_phy(dev, &pcie->plda);
> +	if (ret)
> +		return ret;
> +
> +	ret = clk_bulk_prepare_enable(pcie->num_clks, pcie->clks);
> +	if (ret) {
> +		dev_err(dev, "failed to enable clocks\n");
> +		starfive_pcie_disable_phy(&pcie->plda);
> +		return ret;
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct dev_pm_ops starfive_pcie_pm_ops = {
> +	NOIRQ_SYSTEM_SLEEP_PM_OPS(starfive_pcie_suspend_noirq,
> +				  starfive_pcie_resume_noirq)
> +};
> +
> +static const struct of_device_id starfive_pcie_of_match[] = {
> +	{ .compatible = "starfive,jh7110-pcie"},

Missing space before }

> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, starfive_pcie_of_match);
> +
> +static struct platform_driver starfive_pcie_driver = {
> +	.driver = {
> +		.name = "pcie-starfive",
> +		.of_match_table = of_match_ptr(starfive_pcie_of_match),
> +#ifdef CONFIG_PM_SLEEP
> +		.pm = &starfive_pcie_pm_ops,
> +#endif

This can be just .pm = pm_sleep_ptr(&starfive_pcie_pm_ops),

> +	},
> +	.probe = starfive_pcie_probe,
> +	.remove_new = starfive_pcie_remove,
> +};
> +module_platform_driver(starfive_pcie_driver);
> +
> +MODULE_DESCRIPTION("StarFive JH7110 PCIe host driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.17.1