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Subject: Re: [PATCH V7 14/15] PCI: tegra: Add Tegra194 PCIe support
To:     Thierry Reding <thierry.reding@gmail.com>
CC:     <lorenzo.pieralisi@arm.com>, <bhelgaas@google.com>,
        <robh+dt@kernel.org>, <mark.rutland@arm.com>,
        <jonathanh@nvidia.com>, <kishon@ti.com>, <catalin.marinas@arm.com>,
        <will.deacon@arm.com>, <jingoohan1@gmail.com>,
        <gustavo.pimentel@synopsys.com>, <mperttunen@nvidia.com>,
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        <linux-arm-kernel@lists.infradead.org>, <kthota@nvidia.com>,
        <mmaddireddy@nvidia.com>, <sagar.tv@gmail.com>
References: <20190517123846.3708-1-vidyas@nvidia.com>
 <20190517123846.3708-15-vidyas@nvidia.com> <20190521114133.GN29166@ulmo>
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From:   Vidya Sagar <vidyas@nvidia.com>
Message-ID: <8b467db1-0700-a535-b5e5-5e1d3cff12ba@nvidia.com>
Date:   Wed, 22 May 2019 17:35:50 +0530
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On 5/21/2019 5:11 PM, Thierry Reding wrote:
> On Fri, May 17, 2019 at 06:08:45PM +0530, Vidya Sagar wrote:
>> Add support for Synopsys DesignWare core IP based PCIe host controller
>> present in Tegra194 SoC.
>>
>> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
>> ---
>> Changes since [v6]:
>> * Removed code around "nvidia,disable-aspm-states" DT property
>> * Refactored code to remove code duplication
>>
>> Changes since [v5]:
>> * Addressed review comments from Thierry
>>
>> Changes since [v4]:
>> * None
>>
>> Changes since [v3]:
>> * None
>>
>> Changes since [v2]:
>> * Changed 'nvidia,init-speed' to 'nvidia,init-link-speed'
>> * Changed 'nvidia,pex-wake' to 'nvidia,wake-gpios'
>> * Removed .runtime_suspend() & .runtime_resume() implementations
>>
>> Changes since [v1]:
>> * Made CONFIG_PCIE_TEGRA194 as 'm' by default from its previous 'y' state
>> * Modified code as per changes made to DT documentation
>> * Refactored code to address Bjorn & Thierry's review comments
>> * Added goto to avoid recursion in tegra_pcie_dw_host_init() API
>> * Merged .scan_bus() of dw_pcie_host_ops implementation to tegra_pcie_dw_host_init() API
>>
>>   drivers/pci/controller/dwc/Kconfig         |   10 +
>>   drivers/pci/controller/dwc/Makefile        |    1 +
>>   drivers/pci/controller/dwc/pcie-tegra194.c | 1620 ++++++++++++++++++++
>>   3 files changed, 1631 insertions(+)
>>   create mode 100644 drivers/pci/controller/dwc/pcie-tegra194.c
>>
>> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
>> index a6ce1ee51b4c..c5d71d5d26a0 100644
>> --- a/drivers/pci/controller/dwc/Kconfig
>> +++ b/drivers/pci/controller/dwc/Kconfig
>> @@ -220,6 +220,16 @@ config PCI_MESON
>>   	  and therefore the driver re-uses the DesignWare core functions to
>>   	  implement the driver.
>>   
>> +config PCIE_TEGRA194
>> +	tristate "NVIDIA Tegra194 (and later) PCIe controller"
>> +	depends on (TEGRA_BPMP && ARCH_TEGRA) || COMPILE_TEST
>> +	depends on PCI_MSI_IRQ_DOMAIN
>> +	select PCIE_DW_HOST
>> +	select PHY_TEGRA194_PCIE_P2U
>> +	help
>> +	  Say Y here if you want support for DesignWare core based PCIe host
>> +	  controller found in NVIDIA Tegra194 SoC.
>> +
>>   config PCIE_UNIPHIER
>>   	bool "Socionext UniPhier PCIe controllers"
>>   	depends on ARCH_UNIPHIER || COMPILE_TEST
>> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
>> index b085dfd4fab7..b30336181d46 100644
>> --- a/drivers/pci/controller/dwc/Makefile
>> +++ b/drivers/pci/controller/dwc/Makefile
>> @@ -15,6 +15,7 @@ obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
>>   obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
>>   obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
>>   obj-$(CONFIG_PCI_MESON) += pci-meson.o
>> +obj-$(CONFIG_PCIE_TEGRA194) += pcie-tegra194.o
>>   obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
>>   
>>   # The following drivers are for devices that use the generic ACPI
>> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
>> new file mode 100644
>> index 000000000000..4b3a1d4125b6
>> --- /dev/null
>> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
>> @@ -0,0 +1,1620 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * PCIe host controller driver for Tegra194 SoC
>> + *
>> + * Copyright (C) 2019 NVIDIA Corporation.
>> + *
>> + * Author: Vidya Sagar <vidyas@nvidia.com>
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/debugfs.h>
>> +#include <linux/delay.h>
>> +#include <linux/gpio.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/kernel.h>
>> +#include <linux/kfifo.h>
>> +#include <linux/kthread.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/of_pci.h>
>> +#include <linux/pci.h>
>> +#include <linux/pci-aspm.h>
>> +#include <linux/phy/phy.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/random.h>
>> +#include <linux/reset.h>
>> +#include <linux/resource.h>
>> +#include <linux/types.h>
>> +#include "pcie-designware.h"
>> +#include <soc/tegra/bpmp.h>
>> +#include <soc/tegra/bpmp-abi.h>
>> +#include "../../pci.h"
>> +
>> +#define CTRL_5	5
> 
> There isn't really a need for this since you only use it once and the
> CTRL_ prefix doesn't really add any contextual information in that case.
> Might as well just hardcode that 5 in the one location.
Ok.

> 
>> +
>> +#define APPL_PINMUX				0x0
>> +#define APPL_PINMUX_PEX_RST			BIT(0)
>> +#define APPL_PINMUX_CLKREQ_OVERRIDE_EN		BIT(2)
>> +#define APPL_PINMUX_CLKREQ_OVERRIDE		BIT(3)
>> +#define APPL_PINMUX_CLK_OUTPUT_IN_OVERRIDE_EN	BIT(4)
>> +#define APPL_PINMUX_CLK_OUTPUT_IN_OVERRIDE	BIT(5)
>> +#define APPL_PINMUX_CLKREQ_OUT_OVRD_EN		BIT(9)
>> +#define APPL_PINMUX_CLKREQ_OUT_OVRD		BIT(10)
>> +
>> +#define APPL_CTRL				0x4
>> +#define APPL_CTRL_SYS_PRE_DET_STATE		BIT(6)
>> +#define APPL_CTRL_LTSSM_EN			BIT(7)
>> +#define APPL_CTRL_HW_HOT_RST_EN			BIT(20)
>> +#define APPL_CTRL_HW_HOT_RST_MODE_MASK		GENMASK(1, 0)
>> +#define APPL_CTRL_HW_HOT_RST_MODE_SHIFT		22
>> +#define APPL_CTRL_HW_HOT_RST_MODE_IMDT_RST	0x1
>> +
>> +#define APPL_INTR_EN_L0_0			0x8
>> +#define APPL_INTR_EN_L0_0_LINK_STATE_INT_EN	BIT(0)
>> +#define APPL_INTR_EN_L0_0_MSI_RCV_INT_EN	BIT(4)
>> +#define APPL_INTR_EN_L0_0_INT_INT_EN		BIT(8)
>> +#define APPL_INTR_EN_L0_0_CDM_REG_CHK_INT_EN	BIT(19)
>> +#define APPL_INTR_EN_L0_0_SYS_INTR_EN		BIT(30)
>> +#define APPL_INTR_EN_L0_0_SYS_MSI_INTR_EN	BIT(31)
>> +
>> +#define APPL_INTR_STATUS_L0			0xC
>> +#define APPL_INTR_STATUS_L0_LINK_STATE_INT	BIT(0)
>> +#define APPL_INTR_STATUS_L0_INT_INT		BIT(8)
>> +#define APPL_INTR_STATUS_L0_CDM_REG_CHK_INT	BIT(18)
>> +
>> +#define APPL_INTR_EN_L1_0_0				0x1C
>> +#define APPL_INTR_EN_L1_0_0_LINK_REQ_RST_NOT_INT_EN	BIT(1)
>> +
>> +#define APPL_INTR_STATUS_L1_0_0				0x20
>> +#define APPL_INTR_STATUS_L1_0_0_LINK_REQ_RST_NOT_CHGED	BIT(1)
>> +
>> +#define APPL_INTR_STATUS_L1_1			0x2C
>> +#define APPL_INTR_STATUS_L1_2			0x30
>> +#define APPL_INTR_STATUS_L1_3			0x34
>> +#define APPL_INTR_STATUS_L1_6			0x3C
>> +#define APPL_INTR_STATUS_L1_7			0x40
>> +
>> +#define APPL_INTR_EN_L1_8_0			0x44
>> +#define APPL_INTR_EN_L1_8_BW_MGT_INT_EN		BIT(2)
>> +#define APPL_INTR_EN_L1_8_AUTO_BW_INT_EN	BIT(3)
>> +#define APPL_INTR_EN_L1_8_INTX_EN		BIT(11)
>> +#define APPL_INTR_EN_L1_8_AER_INT_EN		BIT(15)
>> +
>> +#define APPL_INTR_STATUS_L1_8_0			0x4C
>> +#define APPL_INTR_STATUS_L1_8_0_EDMA_INT_MASK	GENMASK(11, 6)
>> +#define APPL_INTR_STATUS_L1_8_0_BW_MGT_INT_STS	BIT(2)
>> +#define APPL_INTR_STATUS_L1_8_0_AUTO_BW_INT_STS	BIT(3)
>> +
>> +#define APPL_INTR_STATUS_L1_9			0x54
>> +#define APPL_INTR_STATUS_L1_10			0x58
>> +#define APPL_INTR_STATUS_L1_11			0x64
>> +#define APPL_INTR_STATUS_L1_13			0x74
>> +#define APPL_INTR_STATUS_L1_14			0x78
>> +#define APPL_INTR_STATUS_L1_15			0x7C
>> +#define APPL_INTR_STATUS_L1_17			0x88
>> +
>> +#define APPL_INTR_EN_L1_18				0x90
>> +#define APPL_INTR_EN_L1_18_CDM_REG_CHK_CMPLT		BIT(2)
>> +#define APPL_INTR_EN_L1_18_CDM_REG_CHK_CMP_ERR		BIT(1)
>> +#define APPL_INTR_EN_L1_18_CDM_REG_CHK_LOGIC_ERR	BIT(0)
>> +
>> +#define APPL_INTR_STATUS_L1_18				0x94
>> +#define APPL_INTR_STATUS_L1_18_CDM_REG_CHK_CMPLT	BIT(2)
>> +#define APPL_INTR_STATUS_L1_18_CDM_REG_CHK_CMP_ERR	BIT(1)
>> +#define APPL_INTR_STATUS_L1_18_CDM_REG_CHK_LOGIC_ERR	BIT(0)
>> +
>> +#define APPL_MSI_CTRL_2				0xB0
>> +
>> +#define APPL_LTR_MSG_1				0xC4
>> +#define LTR_MSG_REQ				BIT(15)
>> +#define LTR_MST_NO_SNOOP_SHIFT			16
>> +
>> +#define APPL_LTR_MSG_2				0xC8
>> +#define APPL_LTR_MSG_2_LTR_MSG_REQ_STATE	BIT(3)
>> +
>> +#define APPL_LINK_STATUS			0xCC
>> +#define APPL_LINK_STATUS_RDLH_LINK_UP		BIT(0)
>> +
>> +#define APPL_DEBUG				0xD0
>> +#define APPL_DEBUG_PM_LINKST_IN_L2_LAT		BIT(21)
>> +#define APPL_DEBUG_PM_LINKST_IN_L0		0x11
>> +#define APPL_DEBUG_LTSSM_STATE_MASK		GENMASK(8, 3)
>> +#define APPL_DEBUG_LTSSM_STATE_SHIFT		3
>> +#define LTSSM_STATE_PRE_DETECT			5
>> +
>> +#define APPL_RADM_STATUS			0xE4
>> +#define APPL_PM_XMT_TURNOFF_STATE		BIT(0)
>> +
>> +#define APPL_DM_TYPE				0x100
>> +#define APPL_DM_TYPE_MASK			GENMASK(3, 0)
>> +#define APPL_DM_TYPE_RP				0x4
>> +#define APPL_DM_TYPE_EP				0x0
>> +
>> +#define APPL_CFG_BASE_ADDR			0x104
>> +#define APPL_CFG_BASE_ADDR_MASK			GENMASK(31, 12)
>> +
>> +#define APPL_CFG_IATU_DMA_BASE_ADDR		0x108
>> +#define APPL_CFG_IATU_DMA_BASE_ADDR_MASK	GENMASK(31, 18)
>> +
>> +#define APPL_CFG_MISC				0x110
>> +#define APPL_CFG_MISC_SLV_EP_MODE		BIT(14)
>> +#define APPL_CFG_MISC_ARCACHE_MASK		GENMASK(13, 10)
>> +#define APPL_CFG_MISC_ARCACHE_SHIFT		10
>> +#define APPL_CFG_MISC_ARCACHE_VAL		3
>> +
>> +#define APPL_CFG_SLCG_OVERRIDE			0x114
>> +#define APPL_CFG_SLCG_OVERRIDE_SLCG_EN_MASTER	BIT(0)
>> +
>> +#define APPL_CAR_RESET_OVRD				0x12C
>> +#define APPL_CAR_RESET_OVRD_CYA_OVERRIDE_CORE_RST_N	BIT(0)
>> +
>> +#define IO_BASE_IO_DECODE				BIT(0)
>> +#define IO_BASE_IO_DECODE_BIT8				BIT(8)
>> +
>> +#define CFG_PREF_MEM_LIMIT_BASE_MEM_DECODE		BIT(0)
>> +#define CFG_PREF_MEM_LIMIT_BASE_MEM_LIMIT_DECODE	BIT(16)
>> +
>> +#define CFG_TIMER_CTRL_MAX_FUNC_NUM_OFF	0x718
>> +#define CFG_TIMER_CTRL_ACK_NAK_SHIFT	(19)
>> +
>> +#define EVENT_COUNTER_ALL_CLEAR		0x3
>> +#define EVENT_COUNTER_ENABLE_ALL	0x7
>> +#define EVENT_COUNTER_ENABLE_SHIFT	2
>> +#define EVENT_COUNTER_EVENT_SEL_MASK	GENMASK(7, 0)
>> +#define EVENT_COUNTER_EVENT_SEL_SHIFT	16
>> +#define EVENT_COUNTER_EVENT_Tx_L0S	0x2
>> +#define EVENT_COUNTER_EVENT_Rx_L0S	0x3
>> +#define EVENT_COUNTER_EVENT_L1		0x5
>> +#define EVENT_COUNTER_EVENT_L1_1	0x7
>> +#define EVENT_COUNTER_EVENT_L1_2	0x8
>> +#define EVENT_COUNTER_GROUP_SEL_SHIFT	24
>> +#define EVENT_COUNTER_GROUP_5		0x5
>> +
>> +#define PORT_LOGIC_ACK_F_ASPM_CTRL			0x70C
>> +#define ENTER_ASPM					BIT(30)
>> +#define L0S_ENTRANCE_LAT_SHIFT				24
>> +#define L0S_ENTRANCE_LAT_MASK				GENMASK(26, 24)
>> +#define L1_ENTRANCE_LAT_SHIFT				27
>> +#define L1_ENTRANCE_LAT_MASK				GENMASK(29, 27)
>> +#define N_FTS_SHIFT					8
>> +#define N_FTS_MASK					GENMASK(7, 0)
>> +#define N_FTS_VAL					52
>> +
>> +#define PORT_LOGIC_GEN2_CTRL				0x80C
>> +#define PORT_LOGIC_GEN2_CTRL_DIRECT_SPEED_CHANGE	BIT(17)
>> +#define FTS_MASK					GENMASK(7, 0)
>> +#define FTS_VAL						52
>> +
>> +#define PORT_LOGIC_MSI_CTRL_INT_0_EN		0x828
>> +
>> +#define GEN3_EQ_CONTROL_OFF			0x8a8
>> +#define GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_SHIFT	8
>> +#define GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_MASK	GENMASK(23, 8)
>> +#define GEN3_EQ_CONTROL_OFF_FB_MODE_MASK	GENMASK(3, 0)
>> +
>> +#define GEN3_RELATED_OFF			0x890
>> +#define GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL	BIT(0)
>> +#define GEN3_RELATED_OFF_GEN3_EQ_DISABLE	BIT(16)
>> +#define GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT	24
>> +#define GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK	GENMASK(25, 24)
>> +
>> +#define PORT_LOGIC_AMBA_ERROR_RESPONSE_DEFAULT	0x8D0
>> +#define AMBA_ERROR_RESPONSE_CRS_SHIFT		3
>> +#define AMBA_ERROR_RESPONSE_CRS_MASK		GENMASK(1, 0)
>> +#define AMBA_ERROR_RESPONSE_CRS_OKAY		0
>> +#define AMBA_ERROR_RESPONSE_CRS_OKAY_FFFFFFFF	1
>> +#define AMBA_ERROR_RESPONSE_CRS_OKAY_FFFF0001	2
>> +
>> +#define PORT_LOGIC_MSIX_DOORBELL			0x948
>> +
>> +#define CAP_SPCIE_CAP_OFF			0x154
>> +#define CAP_SPCIE_CAP_OFF_DSP_TX_PRESET0_MASK	GENMASK(3, 0)
>> +#define CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_MASK	GENMASK(11, 8)
>> +#define CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_SHIFT	8
>> +
>> +#define PL16G_CAP_OFF_DSP_16G_TX_PRESET_MASK	GENMASK(3, 0)
>> +#define PL16G_CAP_OFF_USP_16G_TX_PRESET_MASK	GENMASK(7, 4)
>> +#define PL16G_CAP_OFF_USP_16G_TX_PRESET_SHIFT	4
>> +
>> +#define PME_ACK_TIMEOUT 10000
>> +
>> +#define LTSSM_TIMEOUT 50000	/* 50ms */
>> +
>> +#define GEN3_GEN4_EQ_PRESET_INIT	5
>> +
>> +#define GEN1_CORE_CLK_FREQ	62500000
>> +#define GEN2_CORE_CLK_FREQ	125000000
>> +#define GEN3_CORE_CLK_FREQ	250000000
>> +#define GEN4_CORE_CLK_FREQ	500000000
>> +
>> +static const unsigned int pcie_gen_freq[] = {
>> +	GEN1_CORE_CLK_FREQ,
>> +	GEN2_CORE_CLK_FREQ,
>> +	GEN3_CORE_CLK_FREQ,
>> +	GEN4_CORE_CLK_FREQ
>> +};
>> +
>> +static const u32 event_cntr_ctrl_offset[] = {
>> +	0x1d8,
>> +	0x1a8,
>> +	0x1a8,
>> +	0x1a8,
>> +	0x1c4,
>> +	0x1d8
>> +};
>> +
>> +static const u32 event_cntr_data_offset[] = {
>> +	0x1dc,
>> +	0x1ac,
>> +	0x1ac,
>> +	0x1ac,
>> +	0x1c8,
>> +	0x1dc
>> +};
>> +
>> +struct tegra_pcie_dw {
>> +	struct device *dev;
>> +	struct resource *appl_res;
>> +	struct resource *dbi_res;
>> +	struct resource *atu_dma_res;
>> +	void __iomem *appl_base;
>> +	struct clk *core_clk;
>> +	struct reset_control *core_apb_rst;
>> +	struct reset_control *core_rst;
>> +	struct dw_pcie pci;
>> +	enum dw_pcie_device_mode mode;
>> +	struct tegra_bpmp *bpmp;
>> +
>> +	bool supports_clkreq;
>> +	u8 init_link_width;
>> +	bool link_state;
>> +	u32 msi_ctrl_int;
>> +	u32 num_lanes;
>> +	u32 max_speed;
>> +	u32 cid;
>> +	bool update_fc_fixup;
>> +	u32 cfg_link_cap_l1sub;
>> +	u32 pcie_cap_base;
>> +	u32 aspm_cmrt;
>> +	u32 aspm_pwr_on_t;
>> +	u32 aspm_l0s_enter_lat;
>> +
>> +	struct regulator *pex_ctl_supply;
>> +
>> +	u32 phy_count;
> 
> This doesn't need to be a sized type. unsigned int would do just fine.
Ok.

> 
>> +	struct phy **phys;
>> +
>> +	struct dentry *debugfs;
>> +};
>> +
>> +static inline struct tegra_pcie_dw *to_tegra_pcie(struct dw_pcie *pci)
>> +{
>> +	return container_of(pci, struct tegra_pcie_dw, pci);
>> +}
>> +
>> +struct tegra_pcie_soc {
>> +	enum dw_pcie_device_mode mode;
>> +};
>> +
>> +static void apply_bad_link_workaround(struct pcie_port *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
>> +	u32 current_link_width;
>> +	u16 val;
>> +
>> +	/*
>> +	 * NOTE:- Since this scenario is uncommon and link as such is not
>> +	 * stable anyway, not waiting to confirm if link is really
>> +	 * transitioning to Gen-2 speed
>> +	 */
>> +	val = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA);
>> +	if (val & PCI_EXP_LNKSTA_LBMS) {
>> +		current_link_width = (val & PCI_EXP_LNKSTA_NLW) >>
>> +				     PCI_EXP_LNKSTA_NLW_SHIFT;
>> +		if (pcie->init_link_width > current_link_width) {
>> +			dev_warn(pci->dev, "PCIe link is bad, width reduced\n");
>> +			val = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
>> +						PCI_EXP_LNKCTL2);
>> +			val &= ~PCI_EXP_LNKCTL2_TLS;
>> +			val |= PCI_EXP_LNKCTL2_TLS_2_5GT;
>> +			dw_pcie_writew_dbi(pci, pcie->pcie_cap_base +
>> +					   PCI_EXP_LNKCTL2, val);
>> +
>> +			val = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
>> +						PCI_EXP_LNKCTL);
>> +			val |= PCI_EXP_LNKCTL_RL;
>> +			dw_pcie_writew_dbi(pci, pcie->pcie_cap_base +
>> +					   PCI_EXP_LNKCTL, val);
>> +		}
>> +	}
>> +}
>> +
>> +static irqreturn_t tegra_pcie_rp_irq_handler(struct tegra_pcie_dw *pcie)
>> +{
>> +	struct dw_pcie *pci = &pcie->pci;
>> +	struct pcie_port *pp = &pci->pp;
>> +	u32 val, tmp;
>> +	u16 val_w;
>> +
>> +	val = readl(pcie->appl_base + APPL_INTR_STATUS_L0);
>> +	if (val & APPL_INTR_STATUS_L0_LINK_STATE_INT) {
>> +		val = readl(pcie->appl_base + APPL_INTR_STATUS_L1_0_0);
>> +		if (val & APPL_INTR_STATUS_L1_0_0_LINK_REQ_RST_NOT_CHGED) {
>> +			writel(val, pcie->appl_base + APPL_INTR_STATUS_L1_0_0);
>> +
>> +			/* SBR & Surprise Link Down WAR */
>> +			val = readl(pcie->appl_base + APPL_CAR_RESET_OVRD);
>> +			val &= ~APPL_CAR_RESET_OVRD_CYA_OVERRIDE_CORE_RST_N;
>> +			writel(val, pcie->appl_base + APPL_CAR_RESET_OVRD);
>> +			udelay(1);
>> +			val = readl(pcie->appl_base + APPL_CAR_RESET_OVRD);
>> +			val |= APPL_CAR_RESET_OVRD_CYA_OVERRIDE_CORE_RST_N;
>> +			writel(val, pcie->appl_base + APPL_CAR_RESET_OVRD);
>> +
>> +			val = dw_pcie_readl_dbi(pci, PORT_LOGIC_GEN2_CTRL);
>> +			val |= PORT_LOGIC_GEN2_CTRL_DIRECT_SPEED_CHANGE;
>> +			dw_pcie_writel_dbi(pci, PORT_LOGIC_GEN2_CTRL, val);
>> +		}
>> +	}
>> +	if (val & APPL_INTR_STATUS_L0_INT_INT) {
> 
> I think you could use a blank line here (and elsewhere) to separate
> blocks of code for better readability.
Done.

> 
>> +		val = readl(pcie->appl_base + APPL_INTR_STATUS_L1_8_0);
>> +		if (val & APPL_INTR_STATUS_L1_8_0_AUTO_BW_INT_STS) {
>> +			writel(APPL_INTR_STATUS_L1_8_0_AUTO_BW_INT_STS,
>> +			       pcie->appl_base + APPL_INTR_STATUS_L1_8_0);
>> +			apply_bad_link_workaround(pp);
>> +		}
>> +		if (val & APPL_INTR_STATUS_L1_8_0_BW_MGT_INT_STS) {
>> +			writel(APPL_INTR_STATUS_L1_8_0_BW_MGT_INT_STS,
>> +			       pcie->appl_base + APPL_INTR_STATUS_L1_8_0);
>> +
>> +			val_w = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
>> +						  PCI_EXP_LNKSTA);
>> +			dev_dbg(pci->dev, "Link Speed : Gen-%u\n", val_w &
>> +				PCI_EXP_LNKSTA_CLS);
>> +		}
>> +	}
>> +	val = readl(pcie->appl_base + APPL_INTR_STATUS_L0);
>> +	if (val & APPL_INTR_STATUS_L0_CDM_REG_CHK_INT) {
>> +		val = readl(pcie->appl_base + APPL_INTR_STATUS_L1_18);
>> +		tmp = dw_pcie_readl_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS);
>> +		if (val & APPL_INTR_STATUS_L1_18_CDM_REG_CHK_CMPLT) {
>> +			dev_info(pci->dev, "CDM check complete\n");
>> +			tmp |= PCIE_PL_CHK_REG_CHK_REG_COMPLETE;
>> +		}
>> +		if (val & APPL_INTR_STATUS_L1_18_CDM_REG_CHK_CMP_ERR) {
>> +			dev_err(pci->dev, "CDM comparison mismatch\n");
>> +			tmp |= PCIE_PL_CHK_REG_CHK_REG_COMPARISON_ERROR;
>> +		}
>> +		if (val & APPL_INTR_STATUS_L1_18_CDM_REG_CHK_LOGIC_ERR) {
>> +			dev_err(pci->dev, "CDM Logic error\n");
>> +			tmp |= PCIE_PL_CHK_REG_CHK_REG_LOGIC_ERROR;
>> +		}
>> +		dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS, tmp);
>> +		tmp = dw_pcie_readl_dbi(pci, PCIE_PL_CHK_REG_ERR_ADDR);
>> +		dev_err(pci->dev, "CDM Error Address Offset = 0x%08X\n", tmp);
>> +	}
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static irqreturn_t tegra_pcie_irq_handler(int irq, void *arg)
>> +{
>> +	struct tegra_pcie_dw *pcie = (struct tegra_pcie_dw *)arg;
> 
> No need for this explicit cast.
Ok.

> 
>> +
>> +	if (pcie->mode == DW_PCIE_RC_TYPE)
>> +		return tegra_pcie_rp_irq_handler(pcie);
>> +
>> +	return IRQ_NONE;
>> +}
>> +
>> +static int tegra_pcie_dw_rd_own_conf(struct pcie_port *pp, int where, int size,
>> +				     u32 *val)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +
>> +	/*
>> +	 * This is an endpoint mode specific register happen to appear even
>> +	 * when controller is operating in root port mode and system hangs
>> +	 * when it is accessed with link being in ASPM-L1 state.
>> +	 * So skip accessing it altogether
>> +	 */
>> +	if (where == PORT_LOGIC_MSIX_DOORBELL) {
>> +		*val = 0x00000000;
>> +		return PCIBIOS_SUCCESSFUL;
>> +	}
>> +
>> +	return dw_pcie_read(pci->dbi_base + where, size, val);
>> +}
>> +
>> +static int tegra_pcie_dw_wr_own_conf(struct pcie_port *pp, int where, int size,
>> +				     u32 val)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +
>> +	/*
>> +	 * This is an endpoint mode specific register happen to appear even
>> +	 * when controller is operating in root port mode and system hangs
>> +	 * when it is accessed with link being in ASPM-L1 state.
>> +	 * So skip accessing it altogether
>> +	 */
>> +	if (where == PORT_LOGIC_MSIX_DOORBELL)
>> +		return PCIBIOS_SUCCESSFUL;
>> +
>> +	return dw_pcie_write(pci->dbi_base + where, size, val);
>> +}
>> +
>> +#if defined(CONFIG_PCIEASPM)
>> +static void disable_aspm_l11(struct tegra_pcie_dw *pcie)
>> +{
>> +	u32 val;
>> +
>> +	val = dw_pcie_readl_dbi(&pcie->pci, pcie->cfg_link_cap_l1sub);
>> +	val &= ~PCI_L1SS_CAP_ASPM_L1_1;
>> +	dw_pcie_writel_dbi(&pcie->pci, pcie->cfg_link_cap_l1sub, val);
>> +}
>> +
>> +static void disable_aspm_l12(struct tegra_pcie_dw *pcie)
>> +{
>> +	u32 val;
>> +
>> +	val = dw_pcie_readl_dbi(&pcie->pci, pcie->cfg_link_cap_l1sub);
>> +	val &= ~PCI_L1SS_CAP_ASPM_L1_2;
>> +	dw_pcie_writel_dbi(&pcie->pci, pcie->cfg_link_cap_l1sub, val);
>> +}
>> +
>> +static inline u32 event_counter_prog(struct tegra_pcie_dw *pcie, u32 event)
>> +{
>> +	u32 val;
>> +
>> +	val = dw_pcie_readl_dbi(&pcie->pci, event_cntr_ctrl_offset[pcie->cid]);
>> +	val &= ~(EVENT_COUNTER_EVENT_SEL_MASK << EVENT_COUNTER_EVENT_SEL_SHIFT);
>> +	val |= EVENT_COUNTER_GROUP_5 << EVENT_COUNTER_GROUP_SEL_SHIFT;
>> +	val |= event << EVENT_COUNTER_EVENT_SEL_SHIFT;
>> +	val |= EVENT_COUNTER_ENABLE_ALL << EVENT_COUNTER_ENABLE_SHIFT;
>> +	dw_pcie_writel_dbi(&pcie->pci, event_cntr_ctrl_offset[pcie->cid], val);
>> +	val = dw_pcie_readl_dbi(&pcie->pci, event_cntr_data_offset[pcie->cid]);
>> +	return val;
>> +}
>> +
>> +static int aspm_state_cnt(struct seq_file *s, void *data)
>> +{
>> +	struct tegra_pcie_dw *pcie = (struct tegra_pcie_dw *)
>> +				     dev_get_drvdata(s->private);
>> +	u32 val;
>> +
>> +	seq_printf(s, "Tx L0s entry count : %u\n",
>> +		   event_counter_prog(pcie, EVENT_COUNTER_EVENT_Tx_L0S));
>> +
>> +	seq_printf(s, "Rx L0s entry count : %u\n",
>> +		   event_counter_prog(pcie, EVENT_COUNTER_EVENT_Rx_L0S));
>> +
>> +	seq_printf(s, "Link L1 entry count : %u\n",
>> +		   event_counter_prog(pcie, EVENT_COUNTER_EVENT_L1));
>> +
>> +	seq_printf(s, "Link L1.1 entry count : %u\n",
>> +		   event_counter_prog(pcie, EVENT_COUNTER_EVENT_L1_1));
>> +
>> +	seq_printf(s, "Link L1.2 entry count : %u\n",
>> +		   event_counter_prog(pcie, EVENT_COUNTER_EVENT_L1_2));
>> +
>> +	/* Clear all counters */
>> +	dw_pcie_writel_dbi(&pcie->pci, event_cntr_ctrl_offset[pcie->cid],
>> +			   EVENT_COUNTER_ALL_CLEAR);
>> +
>> +	/* Re-enable counting */
>> +	val = EVENT_COUNTER_ENABLE_ALL << EVENT_COUNTER_ENABLE_SHIFT;
>> +	val |= EVENT_COUNTER_GROUP_5 << EVENT_COUNTER_GROUP_SEL_SHIFT;
>> +	dw_pcie_writel_dbi(&pcie->pci, event_cntr_ctrl_offset[pcie->cid], val);
>> +
>> +	return 0;
>> +}
>> +#endif
>> +
>> +static int init_debugfs(struct tegra_pcie_dw *pcie)
>> +{
>> +#if defined(CONFIG_PCIEASPM)
>> +	struct dentry *d;
>> +
>> +	d = debugfs_create_devm_seqfile(pcie->dev, "aspm_state_cnt",
>> +					pcie->debugfs, aspm_state_cnt);
>> +	if (IS_ERR_OR_NULL(d))
>> +		dev_err(pcie->dev,
>> +			"Failed to create debugfs file \"aspm_state_cnt\"\n");
>> +#endif
>> +	return 0;
>> +}
>> +
>> +static void tegra_pcie_enable_system_interrupts(struct pcie_port *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
>> +	u32 val;
>> +	u16 val_w;
>> +
>> +	val = readl(pcie->appl_base + APPL_INTR_EN_L0_0);
>> +	val |= APPL_INTR_EN_L0_0_LINK_STATE_INT_EN;
>> +	writel(val, pcie->appl_base + APPL_INTR_EN_L0_0);
>> +
>> +	val = readl(pcie->appl_base + APPL_INTR_EN_L1_0_0);
>> +	val |= APPL_INTR_EN_L1_0_0_LINK_REQ_RST_NOT_INT_EN;
>> +	writel(val, pcie->appl_base + APPL_INTR_EN_L1_0_0);
>> +
>> +	if (of_property_read_bool(pci->dev->of_node, "cdm-check")) {
> 
> This doesn't match the DT bindings if I remember correctly. It might
> also be worth reading this at *_dt_parse() time and storing the result
> in a field of struct tegra_pcie_dw.
Since this is the only place where I'm checking it, I thought, I would parse
DT directly. But, anyway, I'll have a field to store this info.

> 
>> +		val = readl(pcie->appl_base + APPL_INTR_EN_L0_0);
>> +		val |= APPL_INTR_EN_L0_0_CDM_REG_CHK_INT_EN;
>> +		writel(val, pcie->appl_base + APPL_INTR_EN_L0_0);
>> +
>> +		val = readl(pcie->appl_base + APPL_INTR_EN_L1_18);
>> +		val |= APPL_INTR_EN_L1_18_CDM_REG_CHK_CMP_ERR;
>> +		val |= APPL_INTR_EN_L1_18_CDM_REG_CHK_LOGIC_ERR;
>> +		writel(val, pcie->appl_base + APPL_INTR_EN_L1_18);
>> +	}
>> +
>> +	val_w = dw_pcie_readw_dbi(&pcie->pci, pcie->pcie_cap_base +
>> +				  PCI_EXP_LNKSTA);
>> +	pcie->init_link_width = (val_w & PCI_EXP_LNKSTA_NLW) >>
>> +				PCI_EXP_LNKSTA_NLW_SHIFT;
>> +
>> +	val_w = dw_pcie_readw_dbi(&pcie->pci, pcie->pcie_cap_base +
>> +				  PCI_EXP_LNKCTL);
>> +	val_w |= PCI_EXP_LNKCTL_LBMIE;
>> +	dw_pcie_writew_dbi(&pcie->pci, pcie->pcie_cap_base + PCI_EXP_LNKCTL,
>> +			   val_w);
>> +}
>> +
>> +static void tegra_pcie_enable_legacy_interrupts(struct pcie_port *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
>> +	u32 val;
>> +
>> +	/* Enable legacy interrupt generation */
>> +	val = readl(pcie->appl_base + APPL_INTR_EN_L0_0);
>> +	val |= APPL_INTR_EN_L0_0_SYS_INTR_EN;
>> +	val |= APPL_INTR_EN_L0_0_INT_INT_EN;
>> +	writel(val, pcie->appl_base + APPL_INTR_EN_L0_0);
>> +
>> +	val = readl(pcie->appl_base + APPL_INTR_EN_L1_8_0);
>> +	val |= APPL_INTR_EN_L1_8_INTX_EN;
>> +	val |= APPL_INTR_EN_L1_8_AUTO_BW_INT_EN;
>> +	val |= APPL_INTR_EN_L1_8_BW_MGT_INT_EN;
>> +	if (IS_ENABLED(CONFIG_PCIEAER))
>> +		val |= APPL_INTR_EN_L1_8_AER_INT_EN;
>> +	writel(val, pcie->appl_base + APPL_INTR_EN_L1_8_0);
>> +}
>> +
>> +static void tegra_pcie_enable_msi_interrupts(struct pcie_port *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
>> +	u32 val;
>> +
>> +	dw_pcie_msi_init(pp);
>> +
>> +	/* Enable MSI interrupt generation */
>> +	val = readl(pcie->appl_base + APPL_INTR_EN_L0_0);
>> +	val |= APPL_INTR_EN_L0_0_SYS_MSI_INTR_EN;
>> +	val |= APPL_INTR_EN_L0_0_MSI_RCV_INT_EN;
>> +	writel(val, pcie->appl_base + APPL_INTR_EN_L0_0);
>> +}
>> +
>> +static void tegra_pcie_enable_interrupts(struct pcie_port *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
>> +
>> +	/* Clear interrupt statuses before enabling interrupts */
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L0);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_0_0);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_1);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_2);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_3);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_6);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_7);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_8_0);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_9);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_10);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_11);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_13);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_14);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_15);
>> +	writel(0xFFFFFFFF, pcie->appl_base + APPL_INTR_STATUS_L1_17);
>> +
>> +	tegra_pcie_enable_system_interrupts(pp);
>> +	tegra_pcie_enable_legacy_interrupts(pp);
>> +	if (IS_ENABLED(CONFIG_PCI_MSI))
>> +		tegra_pcie_enable_msi_interrupts(pp);
>> +}
>> +
>> +static void config_gen3_gen4_eq_presets(struct tegra_pcie_dw *pcie)
>> +{
>> +	struct dw_pcie *pci = &pcie->pci;
>> +	u32 val, offset, i;
>> +
>> +	/* Program init preset */
>> +	for (i = 0; i < pcie->num_lanes; i++) {
>> +		dw_pcie_read(pci->dbi_base + CAP_SPCIE_CAP_OFF
>> +				 + (i * 2), 2, &val);
>> +		val &= ~CAP_SPCIE_CAP_OFF_DSP_TX_PRESET0_MASK;
>> +		val |= GEN3_GEN4_EQ_PRESET_INIT;
>> +		val &= ~CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_MASK;
>> +		val |= (GEN3_GEN4_EQ_PRESET_INIT <<
>> +			   CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_SHIFT);
>> +		dw_pcie_write(pci->dbi_base + CAP_SPCIE_CAP_OFF
>> +				 + (i * 2), 2, val);
>> +
>> +		offset = dw_pcie_find_ext_capability(pci, PCI_EXT_CAP_ID_PL) +
>> +				PCI_PL_16GT_LE_CTRL;
>> +		dw_pcie_read(pci->dbi_base + offset + i, 1, &val);
>> +		val &= ~PL16G_CAP_OFF_DSP_16G_TX_PRESET_MASK;
>> +		val |= GEN3_GEN4_EQ_PRESET_INIT;
>> +		val &= ~PL16G_CAP_OFF_USP_16G_TX_PRESET_MASK;
>> +		val |= (GEN3_GEN4_EQ_PRESET_INIT <<
>> +			PL16G_CAP_OFF_USP_16G_TX_PRESET_SHIFT);
>> +		dw_pcie_write(pci->dbi_base + offset + i, 1, val);
>> +	}
>> +
>> +	val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF);
>> +	val &= ~GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK;
>> +	dw_pcie_writel_dbi(pci, GEN3_RELATED_OFF, val);
>> +
>> +	val = dw_pcie_readl_dbi(pci, GEN3_EQ_CONTROL_OFF);
>> +	val &= ~GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_MASK;
>> +	val |= (0x3ff << GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_SHIFT);
>> +	val &= ~GEN3_EQ_CONTROL_OFF_FB_MODE_MASK;
>> +	dw_pcie_writel_dbi(pci, GEN3_EQ_CONTROL_OFF, val);
>> +
>> +	val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF);
>> +	val &= ~GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK;
>> +	val |= (0x1 << GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT);
>> +	dw_pcie_writel_dbi(pci, GEN3_RELATED_OFF, val);
>> +
>> +	val = dw_pcie_readl_dbi(pci, GEN3_EQ_CONTROL_OFF);
>> +	val &= ~GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_MASK;
>> +	val |= (0x360 << GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_SHIFT);
>> +	val &= ~GEN3_EQ_CONTROL_OFF_FB_MODE_MASK;
>> +	dw_pcie_writel_dbi(pci, GEN3_EQ_CONTROL_OFF, val);
>> +
>> +	val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF);
>> +	val &= ~GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK;
>> +	dw_pcie_writel_dbi(pci, GEN3_RELATED_OFF, val);
>> +}
>> +
>> +static int tegra_pcie_dw_host_init(struct pcie_port *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
>> +	u32 val, tmp, offset, speed;
>> +	int count;
> 
> Can be unsigned int.
Done.

> 
>> +	u16 val_w;
>> +
>> +core_init:
>> +	count = 200;
>> +#if defined(CONFIG_PCIEASPM)
>> +	offset = dw_pcie_find_ext_capability(pci, PCI_EXT_CAP_ID_L1SS);
>> +	pcie->cfg_link_cap_l1sub = offset + PCI_L1SS_CAP;
>> +#endif
>> +	val = dw_pcie_readl_dbi(pci, PCI_IO_BASE);
>> +	val &= ~(IO_BASE_IO_DECODE | IO_BASE_IO_DECODE_BIT8);
>> +	dw_pcie_writel_dbi(pci, PCI_IO_BASE, val);
>> +
>> +	val = dw_pcie_readl_dbi(pci, PCI_PREF_MEMORY_BASE);
>> +	val |= CFG_PREF_MEM_LIMIT_BASE_MEM_DECODE;
>> +	val |= CFG_PREF_MEM_LIMIT_BASE_MEM_LIMIT_DECODE;
>> +	dw_pcie_writel_dbi(pci, PCI_PREF_MEMORY_BASE, val);
>> +
>> +	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 0);
>> +
>> +	/* Configure FTS */
>> +	val = dw_pcie_readl_dbi(pci, PORT_LOGIC_ACK_F_ASPM_CTRL);
>> +	val &= ~(N_FTS_MASK << N_FTS_SHIFT);
>> +	val |= N_FTS_VAL << N_FTS_SHIFT;
>> +	dw_pcie_writel_dbi(pci, PORT_LOGIC_ACK_F_ASPM_CTRL, val);
>> +
>> +	val = dw_pcie_readl_dbi(pci, PORT_LOGIC_GEN2_CTRL);
>> +	val &= ~FTS_MASK;
>> +	val |= FTS_VAL;
>> +	dw_pcie_writel_dbi(pci, PORT_LOGIC_GEN2_CTRL, val);
>> +
>> +	/* Enable as 0xFFFF0001 response for CRS */
>> +	val = dw_pcie_readl_dbi(pci, PORT_LOGIC_AMBA_ERROR_RESPONSE_DEFAULT);
>> +	val &= ~(AMBA_ERROR_RESPONSE_CRS_MASK << AMBA_ERROR_RESPONSE_CRS_SHIFT);
>> +	val |= (AMBA_ERROR_RESPONSE_CRS_OKAY_FFFF0001 <<
>> +		AMBA_ERROR_RESPONSE_CRS_SHIFT);
>> +	dw_pcie_writel_dbi(pci, PORT_LOGIC_AMBA_ERROR_RESPONSE_DEFAULT, val);
>> +
>> +	/* Configure Max Speed from DT */
>> +	if (pcie->max_speed && pcie->max_speed != -EINVAL) {
>> +		val = dw_pcie_readl_dbi(pci, pcie->pcie_cap_base +
>> +					PCI_EXP_LNKCAP);
>> +		val &= ~PCI_EXP_LNKCAP_SLS;
>> +		val |= pcie->max_speed;
>> +		dw_pcie_writel_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKCAP,
>> +				   val);
>> +	}
>> +
>> +	/* Configure Max lane width from DT */
>> +	val = dw_pcie_readl_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKCAP);
>> +	val &= ~PCI_EXP_LNKCAP_MLW;
>> +	val |= (pcie->num_lanes << PCI_EXP_LNKSTA_NLW_SHIFT);
>> +	dw_pcie_writel_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKCAP, val);
>> +
>> +	config_gen3_gen4_eq_presets(pcie);
>> +
>> +#if defined(CONFIG_PCIEASPM)
>> +	/* Enable ASPM counters */
>> +	val = EVENT_COUNTER_ENABLE_ALL << EVENT_COUNTER_ENABLE_SHIFT;
>> +	val |= EVENT_COUNTER_GROUP_5 << EVENT_COUNTER_GROUP_SEL_SHIFT;
>> +	dw_pcie_writel_dbi(pci, event_cntr_ctrl_offset[pcie->cid], val);
>> +
>> +	/* Program T_cmrt and T_pwr_on values */
>> +	val = dw_pcie_readl_dbi(pci, pcie->cfg_link_cap_l1sub);
>> +	val &= ~(PCI_L1SS_CAP_CM_RESTORE_TIME | PCI_L1SS_CAP_P_PWR_ON_VALUE);
>> +	val |= (pcie->aspm_cmrt << 8);
>> +	val |= (pcie->aspm_pwr_on_t << 19);
>> +	dw_pcie_writel_dbi(pci, pcie->cfg_link_cap_l1sub, val);
>> +
>> +	/* Program L0s and L1 entrance latencies */
>> +	val = dw_pcie_readl_dbi(pci, PORT_LOGIC_ACK_F_ASPM_CTRL);
>> +	val &= ~L0S_ENTRANCE_LAT_MASK;
>> +	val |= (pcie->aspm_l0s_enter_lat << L0S_ENTRANCE_LAT_SHIFT);
>> +	val |= ENTER_ASPM;
>> +	dw_pcie_writel_dbi(pci, PORT_LOGIC_ACK_F_ASPM_CTRL, val);
>> +#endif
>> +	val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF);
>> +	val &= ~GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL;
>> +	dw_pcie_writel_dbi(pci, GEN3_RELATED_OFF, val);
>> +
>> +	if (pcie->update_fc_fixup) {
>> +		val = dw_pcie_readl_dbi(pci, CFG_TIMER_CTRL_MAX_FUNC_NUM_OFF);
>> +		val |= 0x1 << CFG_TIMER_CTRL_ACK_NAK_SHIFT;
>> +		dw_pcie_writel_dbi(pci, CFG_TIMER_CTRL_MAX_FUNC_NUM_OFF, val);
>> +	}
>> +
>> +	dw_pcie_setup_rc(pp);
>> +
>> +	clk_set_rate(pcie->core_clk, GEN4_CORE_CLK_FREQ);
>> +
>> +	/* Assert RST */
>> +	val = readl(pcie->appl_base + APPL_PINMUX);
>> +	val &= ~APPL_PINMUX_PEX_RST;
>> +	writel(val, pcie->appl_base + APPL_PINMUX);
>> +
>> +	usleep_range(100, 200);
>> +
>> +	/* Enable LTSSM */
>> +	val = readl(pcie->appl_base + APPL_CTRL);
>> +	val |= APPL_CTRL_LTSSM_EN;
>> +	writel(val, pcie->appl_base + APPL_CTRL);
>> +
>> +	/* De-assert RST */
>> +	val = readl(pcie->appl_base + APPL_PINMUX);
>> +	val |= APPL_PINMUX_PEX_RST;
>> +	writel(val, pcie->appl_base + APPL_PINMUX);
>> +
>> +	msleep(100);
>> +
>> +	val_w = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA);
>> +	while (!(val_w & PCI_EXP_LNKSTA_DLLLA)) {
>> +		if (count) {
>> +			dev_dbg(pci->dev, "Waiting for link up\n");
>> +			usleep_range(1000, 2000);
>> +			val_w = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base +
>> +						  PCI_EXP_LNKSTA);
>> +			count--;
>> +			continue;
>> +		}
>> +
>> +		val = readl(pcie->appl_base + APPL_DEBUG);
>> +		val &= APPL_DEBUG_LTSSM_STATE_MASK;
>> +		val >>= APPL_DEBUG_LTSSM_STATE_SHIFT;
>> +		tmp = readl(pcie->appl_base + APPL_LINK_STATUS);
>> +		tmp &= APPL_LINK_STATUS_RDLH_LINK_UP;
>> +		if (!(val == 0x11 && !tmp)) {
>> +			dev_info(pci->dev, "Link is down\n");
>> +			return 0;
>> +		}
>> +
>> +		dev_info(pci->dev, "Link is down in DLL");
>> +		dev_info(pci->dev, "Trying again with DLFE disabled\n");
>> +		/* Disable LTSSM */
>> +		val = readl(pcie->appl_base + APPL_CTRL);
>> +		val &= ~APPL_CTRL_LTSSM_EN;
>> +		writel(val, pcie->appl_base + APPL_CTRL);
>> +
>> +		reset_control_assert(pcie->core_rst);
>> +		reset_control_deassert(pcie->core_rst);
>> +
>> +		offset = dw_pcie_find_ext_capability(pci, PCI_EXT_CAP_ID_DLF);
>> +		val = dw_pcie_readl_dbi(pci, offset + PCI_DLF_CAP);
>> +		val &= ~PCI_DLF_EXCHANGE_ENABLE;
>> +		dw_pcie_writel_dbi(pci, offset, val);
>> +
>> +		/* Retry now with DLF Exchange disabled */
>> +		goto core_init;
>> +	}
>> +	dev_dbg(pci->dev, "Link is up\n");
>> +
>> +	speed = (dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA) &
>> +		 PCI_EXP_LNKSTA_CLS);
> 
> No need for the outer parentheses.
Done.

> 
>> +	clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);
>> +
>> +	tegra_pcie_enable_interrupts(pp);
>> +
>> +	return 0;
>> +}
>> +
>> +static int tegra_pcie_dw_link_up(struct dw_pcie *pci)
>> +{
>> +	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
>> +	u32 val = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA);
>> +
>> +	return !!(val & PCI_EXP_LNKSTA_DLLLA);
>> +}
>> +
>> +static void tegra_pcie_set_msi_vec_num(struct pcie_port *pp)
>> +{
>> +	pp->num_vectors = MAX_MSI_IRQS;
>> +}
>> +
>> +static const struct dw_pcie_ops tegra_dw_pcie_ops = {
>> +	.link_up = tegra_pcie_dw_link_up,
>> +};
>> +
>> +static struct dw_pcie_host_ops tegra_pcie_dw_host_ops = {
>> +	.rd_own_conf = tegra_pcie_dw_rd_own_conf,
>> +	.wr_own_conf = tegra_pcie_dw_wr_own_conf,
>> +	.host_init = tegra_pcie_dw_host_init,
>> +	.set_num_vectors = tegra_pcie_set_msi_vec_num,
>> +};
>> +
>> +static void tegra_pcie_disable_phy(struct tegra_pcie_dw *pcie)
>> +{
>> +	u32 phy_count = pcie->phy_count;
>> +
>> +	while (phy_count--) {
>> +		phy_power_off(pcie->phys[phy_count]);
>> +		phy_exit(pcie->phys[phy_count]);
>> +	}
>> +}
>> +
>> +static int tegra_pcie_enable_phy(struct tegra_pcie_dw *pcie)
>> +{
>> +	u32 phy_count = pcie->phy_count;
> 
> This seems unnecessary in this function.
> 
>> +	int ret;
>> +	u32 i;
> 
> Can be unsigned int to match pcie->phy_count.
> 
>> +
>> +	for (i = 0; i < phy_count; i++) {
>> +		ret = phy_init(pcie->phys[i]);
>> +		if (ret < 0)
>> +			goto err_phy_init;
>> +
>> +		ret = phy_power_on(pcie->phys[i]);
>> +		if (ret < 0) {
>> +			phy_exit(pcie->phys[i]);
>> +			goto err_phy_power_on;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +
>> +	while (i >= 0) {
> 
> Oh... looks like this can't be unsigned, otherwise you'll be infinitely
> repeating this loop. Perhaps you can rewrite it like this to avoid that:
> 
> 	while (i--) {
> 		...
> 	}
> 
> That's the most idiomatic way to unwind in my opinion.
It is written this way to handle situations where an intermediate may phy_init() fail
or a phy_power_on() may fail after phy_init() succeeds. This while loops gracefully
undoes whatever has been done already.

> 
>> +		phy_power_off(pcie->phys[i]);
>> +err_phy_power_on:
>> +		phy_exit(pcie->phys[i]);
>> +err_phy_init:
>> +		i--;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int tegra_pcie_dw_parse_dt(struct tegra_pcie_dw *pcie)
>> +{
>> +	struct device_node *np = pcie->dev->of_node;
>> +	int ret;
>> +
>> +	ret = of_property_read_u32(np, "nvidia,aspm-cmrt-us", &pcie->aspm_cmrt);
>> +	if (ret < 0) {
>> +		dev_info(pcie->dev, "Failed to read ASPM T_cmrt: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = of_property_read_u32(np, "nvidia,aspm-pwr-on-t-us",
>> +				   &pcie->aspm_pwr_on_t);
>> +	if (ret < 0)
>> +		dev_info(pcie->dev, "Failed to read ASPM Power On time: %d\n",
>> +			 ret);
>> +
>> +	ret = of_property_read_u32(np, "nvidia,aspm-l0s-entrance-latency-us",
>> +				   &pcie->aspm_l0s_enter_lat);
>> +	if (ret < 0)
>> +		dev_info(pcie->dev,
>> +			 "Failed to read ASPM L0s Entrance latency: %d\n", ret);
>> +
>> +	ret = of_property_read_u32(np, "num-lanes", &pcie->num_lanes);
>> +	if (ret < 0) {
>> +		dev_err(pcie->dev, "Failed to read num-lanes: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	pcie->max_speed = of_pci_get_max_link_speed(np);
>> +
>> +	ret = of_property_read_u32_index(np, "nvidia,bpmp", 1, &pcie->cid);
>> +	if (ret) {
>> +		dev_err(pcie->dev, "Failed to read Controller-ID: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	pcie->phy_count = of_property_count_strings(np, "phy-names");
>> +	if (pcie->phy_count < 0) {
>> +		dev_err(pcie->dev, "Failed to find phy entries\n");
>> +		return pcie->phy_count;
>> +	}
>> +
>> +	if (of_property_read_bool(np, "nvidia,update-fc-fixup"))
>> +		pcie->update_fc_fixup = true;
>> +
>> +	pcie->supports_clkreq =
>> +		of_property_read_bool(pcie->dev->of_node, "supports-clkreq");
>> +
>> +	return 0;
>> +}
>> +
>> +static int tegra_pcie_bpmp_set_ctrl_state(struct tegra_pcie_dw *pcie,
>> +					  int enable)
> 
> Perhaps make this a boolean? That's not an exact match for the
> req.controller_state.enable field defined in the ABI, but it's a bit
> closer than an int. Also, boolean is effectively what the ABI allows,
> so might as well use that.
I want to return the error code of tegra_bpmp_transfer_atomic()/
tegra_bpmp_transfer() directly and they have int return type. I'm not sure
how having boolean is better here? Can you please give more details?

> 
>> +{
>> +	struct mrq_uphy_response resp;
>> +	struct tegra_bpmp_message msg;
>> +	struct mrq_uphy_request req;
>> +	int err;
>> +
>> +	if (pcie->cid == CTRL_5)
>> +		return 0;
>> +
>> +	memset(&req, 0, sizeof(req));
>> +	memset(&resp, 0, sizeof(resp));
>> +
>> +	req.cmd = CMD_UPHY_PCIE_CONTROLLER_STATE;
>> +	req.controller_state.pcie_controller = pcie->cid;
>> +	req.controller_state.enable = enable;
>> +
>> +	memset(&msg, 0, sizeof(msg));
>> +	msg.mrq = MRQ_UPHY;
>> +	msg.tx.data = &req;
>> +	msg.tx.size = sizeof(req);
>> +	msg.rx.data = &resp;
>> +	msg.rx.size = sizeof(resp);
>> +
>> +	if (irqs_disabled())
>> +		err = tegra_bpmp_transfer_atomic(pcie->bpmp, &msg);
>> +	else
>> +		err = tegra_bpmp_transfer(pcie->bpmp, &msg);
>> +
>> +	return err;
>> +}
>> +
>> +static void tegra_pcie_downstream_dev_to_D0(struct tegra_pcie_dw *pcie)
>> +{
>> +	struct pcie_port *pp = &pcie->pci.pp;
>> +	struct pci_dev *pdev;
>> +	struct pci_bus *child;
>> +
>> +	list_for_each_entry(child, &pp->root_bus->children, node) {
>> +		/* Bring downstream devices to D0 if they are not already in */
>> +		if (child->parent == pp->root_bus)
>> +			break;
>> +	}
>> +	list_for_each_entry(pdev, &child->devices, bus_list) {
>> +		if (PCI_FUNC(pdev->devfn) == 0) {
> 
> Why restrict this to function 0? What about other potential functions?
Yes. This should be extended to other functions as well. I'll change it from
PCI_FUNC() to PCI_SLOT() to look for device zero.

> 
> Also, if child devices are not in D0 at this point, isn't that an error?
No. In fact, they are not going to be in D0. They would be in D3_hot or whichever
low power state they support. PCIe sub-system makes sure that.

> Perhaps we should check the power state of the device here and output a
> warning if it's not in D0 so that we can track down which device drivers
> are buggy?
Since they are anyway not going to be in D0 and we are bringing all of them to D0
here, I think it is not required.

> 
>> +			if (pci_set_power_state(pdev, PCI_D0))
>> +				dev_err(pcie->dev, "Transition to D0 failed\n");
> 
> Perhaps output the dev_name() of the PCI device that we failed to
> transition to D0? That could help with tracking down errors.
Done.

> 
>> +		}
>> +	}
>> +}
> 
>> +
>> +static int tegra_pcie_config_controller(struct tegra_pcie_dw *pcie,
>> +					bool en_hw_hot_rst)
>> +{
>> +	int ret;
>> +	u32 val;
>> +
>> +	ret = tegra_pcie_bpmp_set_ctrl_state(pcie, true);
>> +	if (ret) {
>> +		dev_err(pcie->dev,
>> +			"Failed to enable Controller-%d: %d\n",
> 
> This is an unusual way to write this. On one hand there doesn't seem to
> be any consistency between error messages (see the one for failed calls
> to pci_set_power_state()) and on the other hand, that Controller-%d
> looks strange. Perhaps something like:
> 
> 	"failed to enable controller %u: %d\n", pcie->cid, ret
> 
> would be better. Note also the %u, which is preferred when printing
> unsigned integers.
Done.

> 
>> +			pcie->cid, ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = regulator_enable(pcie->pex_ctl_supply);
>> +	if (ret < 0) {
>> +		dev_err(pcie->dev, "Failed to enable regulator: %d\n", ret);
>> +		goto fail_reg_en;
>> +	}
>> +
>> +	ret = clk_prepare_enable(pcie->core_clk);
>> +	if (ret) {
>> +		dev_err(pcie->dev, "Failed to enable core clock\n");
> 
> Perhaps include the error code here in order to help diagnose problems.
> It looks like you have some consistency in error messages here, so feel
> free to follow that in the ones that aren't consistent.
Done.

> 
>> +		goto fail_core_clk;
>> +	}
>> +
>> +	reset_control_deassert(pcie->core_apb_rst);
>> +
>> +	if (en_hw_hot_rst) {
>> +		/* Enable HW_HOT_RST mode */
>> +		val = readl(pcie->appl_base + APPL_CTRL);
>> +		val &= ~(APPL_CTRL_HW_HOT_RST_MODE_MASK <<
>> +			  APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
>> +		val |= APPL_CTRL_HW_HOT_RST_EN;
>> +		writel(val, pcie->appl_base + APPL_CTRL);
>> +	}
>> +
>> +	ret = tegra_pcie_enable_phy(pcie);
>> +	if (ret) {
>> +		dev_err(pcie->dev, "Failed to enable phy\n");
> 
> s/phy/PHY/, and perhaps include the error code.
Done.

> 
>> +		goto fail_phy;
>> +	}
>> +
>> +	/* Update CFG base address */
>> +	writel(pcie->dbi_res->start & APPL_CFG_BASE_ADDR_MASK,
>> +	       pcie->appl_base + APPL_CFG_BASE_ADDR);
>> +
>> +	/* Configure this core for RP mode operation */
>> +	writel(APPL_DM_TYPE_RP, pcie->appl_base + APPL_DM_TYPE);
>> +
>> +	writel(0x0, pcie->appl_base + APPL_CFG_SLCG_OVERRIDE);
>> +
>> +	val = readl(pcie->appl_base + APPL_CTRL);
>> +	writel(val | APPL_CTRL_SYS_PRE_DET_STATE, pcie->appl_base + APPL_CTRL);
>> +
>> +	val = readl(pcie->appl_base + APPL_CFG_MISC);
>> +	val |= (APPL_CFG_MISC_ARCACHE_VAL << APPL_CFG_MISC_ARCACHE_SHIFT);
>> +	writel(val, pcie->appl_base + APPL_CFG_MISC);
>> +
>> +	if (!pcie->supports_clkreq) {
>> +		val = readl(pcie->appl_base + APPL_PINMUX);
>> +		val |= APPL_PINMUX_CLKREQ_OUT_OVRD_EN;
>> +		val |= APPL_PINMUX_CLKREQ_OUT_OVRD;
>> +		writel(val, pcie->appl_base + APPL_PINMUX);
>> +	}
>> +
>> +	/* Update iATU_DMA base address */
>> +	writel(pcie->atu_dma_res->start & APPL_CFG_IATU_DMA_BASE_ADDR_MASK,
>> +	       pcie->appl_base + APPL_CFG_IATU_DMA_BASE_ADDR);
>> +
>> +	reset_control_deassert(pcie->core_rst);
> 
> Technically this could fail.
Done. Added a check here as well.
> 
>> +
>> +	pcie->pcie_cap_base = dw_pcie_find_capability(&pcie->pci,
>> +						      PCI_CAP_ID_EXP);
>> +
>> +#if defined(CONFIG_PCIEASPM)
>> +	/* Disable ASPM-L1SS advertisement as there is no CLKREQ routing */
>> +	if (!pcie->supports_clkreq) {
>> +		disable_aspm_l11(pcie);
>> +		disable_aspm_l12(pcie);
>> +	}
>> +#endif
>> +	return ret;
>> +
>> +fail_phy:
>> +	reset_control_assert(pcie->core_apb_rst);
>> +	clk_disable_unprepare(pcie->core_clk);
>> +fail_core_clk:
>> +	regulator_disable(pcie->pex_ctl_supply);
>> +fail_reg_en:
>> +	tegra_pcie_bpmp_set_ctrl_state(pcie, false);
>> +
>> +	return ret;
>> +}
>> +
>> +static int __deinit_controller(struct tegra_pcie_dw *pcie)
>> +{
>> +	int ret;
>> +
>> +	ret = reset_control_assert(pcie->core_rst);
>> +	if (ret) {
>> +		dev_err(pcie->dev, "Failed to assert \"core\" reset: %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +	tegra_pcie_disable_phy(pcie);
>> +	ret = reset_control_assert(pcie->core_apb_rst);
>> +	if (ret) {
>> +		dev_err(pcie->dev, "Failed to assert \"core_apb\" reset: %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +	clk_disable_unprepare(pcie->core_clk);
>> +	ret = regulator_disable(pcie->pex_ctl_supply);
>> +	if (ret) {
>> +		dev_err(pcie->dev, "Failed to disable regulator: %d\n", ret);
>> +		return ret;
>> +	}
>> +	ret = tegra_pcie_bpmp_set_ctrl_state(pcie, false);
>> +	if (ret) {
>> +		dev_err(pcie->dev, "Failed to disable controller-%d: %d\n",
>> +			pcie->cid, ret);
>> +		return ret;
>> +	}
>> +	return ret;
>> +}
>> +
>> +static int tegra_pcie_init_controller(struct tegra_pcie_dw *pcie)
>> +{
>> +	struct dw_pcie *pci = &pcie->pci;
>> +	struct pcie_port *pp = &pci->pp;
>> +	int ret = 0;
> 
> No need to initialize this.
> 
>> +
>> +	ret = tegra_pcie_config_controller(pcie, false);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	pp->root_bus_nr = -1;
>> +	pp->ops = &tegra_pcie_dw_host_ops;
>> +
>> +	ret = dw_pcie_host_init(pp);
>> +	if (ret < 0) {
>> +		dev_err(pcie->dev, "Failed to add PCIe port: %d\n", ret);
> 
> Perhaps mention which port? Or is this uniquely identified by
> dev_name(pcie->dev) already?
This is uniquely identified by dev_name(pcie->dev) already.

> 
>> +		goto fail_host_init;
>> +	}
>> +
>> +	return 0;
>> +
>> +fail_host_init:
>> +	return __deinit_controller(pcie);
>> +}
>> +
>> +static int tegra_pcie_try_link_l2(struct tegra_pcie_dw *pcie)
>> +{
>> +	u32 val;
>> +
>> +	if (!tegra_pcie_dw_link_up(&pcie->pci))
>> +		return 0;
>> +
>> +	val = readl(pcie->appl_base + APPL_RADM_STATUS);
>> +	val |= APPL_PM_XMT_TURNOFF_STATE;
>> +	writel(val, pcie->appl_base + APPL_RADM_STATUS);
>> +
>> +	return readl_poll_timeout_atomic(pcie->appl_base + APPL_DEBUG, val,
>> +				 val & APPL_DEBUG_PM_LINKST_IN_L2_LAT,
>> +				 1, PME_ACK_TIMEOUT);
>> +}
>> +
>> +static void tegra_pcie_dw_pme_turnoff(struct tegra_pcie_dw *pcie)
>> +{
>> +	u32 data;
>> +	int err;
>> +
>> +	if (!tegra_pcie_dw_link_up(&pcie->pci)) {
>> +		dev_dbg(pcie->dev, "PCIe link is not up...!\n");
>> +		return;
>> +	}
>> +
>> +	if (tegra_pcie_try_link_l2(pcie)) {
>> +		dev_info(pcie->dev, "Link didn't transition to L2 state\n");
>> +		/*
>> +		 * TX lane clock freq will reset to Gen1 only if link is in L2
>> +		 * or detect state.
>> +		 * So apply pex_rst to end point to force RP to go into detect
>> +		 * state
>> +		 */
>> +		data = readl(pcie->appl_base + APPL_PINMUX);
>> +		data &= ~APPL_PINMUX_PEX_RST;
>> +		writel(data, pcie->appl_base + APPL_PINMUX);
>> +
>> +		err = readl_poll_timeout_atomic(pcie->appl_base + APPL_DEBUG,
>> +						data,
>> +						((data &
>> +						APPL_DEBUG_LTSSM_STATE_MASK) >>
>> +						APPL_DEBUG_LTSSM_STATE_SHIFT) ==
>> +						LTSSM_STATE_PRE_DETECT,
>> +						1, LTSSM_TIMEOUT);
>> +		if (err) {
>> +			dev_info(pcie->dev, "Link didn't go to detect state\n");
>> +		} else {
>> +			/* Disable LTSSM after link is in detect state */
>> +			data = readl(pcie->appl_base + APPL_CTRL);
>> +			data &= ~APPL_CTRL_LTSSM_EN;
>> +			writel(data, pcie->appl_base + APPL_CTRL);
>> +		}
>> +	}
>> +	/*
>> +	 * DBI registers may not be accessible after this as PLL-E would be
>> +	 * down depending on how CLKREQ is pulled by end point
>> +	 */
>> +	data = readl(pcie->appl_base + APPL_PINMUX);
>> +	data |= (APPL_PINMUX_CLKREQ_OVERRIDE_EN | APPL_PINMUX_CLKREQ_OVERRIDE);
>> +	/* Cut REFCLK to slot */
>> +	data |= APPL_PINMUX_CLK_OUTPUT_IN_OVERRIDE_EN;
>> +	data &= ~APPL_PINMUX_CLK_OUTPUT_IN_OVERRIDE;
>> +	writel(data, pcie->appl_base + APPL_PINMUX);
>> +}
>> +
>> +static int tegra_pcie_deinit_controller(struct tegra_pcie_dw *pcie)
>> +{
>> +	/*
>> +	 * link doesn't go into L2 state with some of the endpoints with Tegra
>> +	 * if they are not in D0 state. So, need to make sure that immediate
>> +	 * downstream devices are in D0 state before sending PME_TurnOff to put
>> +	 * link into L2 state
>> +	 */
>> +	tegra_pcie_downstream_dev_to_D0(pcie);
>> +	dw_pcie_host_deinit(&pcie->pci.pp);
>> +	tegra_pcie_dw_pme_turnoff(pcie);
>> +	return __deinit_controller(pcie);
>> +}
>> +
>> +static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
>> +{
>> +	struct pcie_port *pp = &pcie->pci.pp;
>> +	struct device *dev = pcie->dev;
>> +	char *name;
>> +	int ret;
>> +
>> +	if (IS_ENABLED(CONFIG_PCI_MSI)) {
>> +		pp->msi_irq = of_irq_get_byname(dev->of_node, "msi");
>> +		if (!pp->msi_irq) {
>> +			dev_err(dev, "Failed to get MSI interrupt\n");
>> +			return -ENODEV;
>> +		}
>> +	}
>> +
>> +	pm_runtime_enable(dev);
>> +	ret = pm_runtime_get_sync(dev);
>> +	if (ret < 0) {
>> +		dev_err(dev, "Failed to get runtime sync for PCIe dev\n");
>> +		pm_runtime_disable(dev);
>> +		return ret;
>> +	}
>> +
>> +	tegra_pcie_init_controller(pcie);
>> +
>> +	pcie->link_state = tegra_pcie_dw_link_up(&pcie->pci);
>> +
>> +	if (!pcie->link_state) {
>> +		ret = -ENOMEDIUM;
>> +		goto fail_host_init;
>> +	}
>> +
>> +	name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
>> +	if (!name) {
>> +		ret = -ENOMEM;
>> +		goto fail_host_init;
>> +	}
>> +
>> +	pcie->debugfs = debugfs_create_dir(name, NULL);
>> +	if (!pcie->debugfs)
>> +		dev_err(dev, "Failed to create debugfs\n");
>> +	else
>> +		init_debugfs(pcie);
>> +
>> +	return ret;
>> +
>> +fail_host_init:
>> +	tegra_pcie_deinit_controller(pcie);
>> +	pm_runtime_put_sync(dev);
>> +	pm_runtime_disable(dev);
>> +	return ret;
>> +}
>> +
>> +static const struct tegra_pcie_soc tegra_pcie_rc_of_data = {
>> +	.mode = DW_PCIE_RC_TYPE,
>> +};
>> +
>> +static const struct of_device_id tegra_pcie_dw_of_match[] = {
>> +	{
>> +		.compatible = "nvidia,tegra194-pcie",
>> +		.data = &tegra_pcie_rc_of_data,
>> +	},
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, tegra_pcie_dw_of_match);
>> +
>> +static int tegra_pcie_dw_probe(struct platform_device *pdev)
>> +{
>> +	const struct tegra_pcie_soc *data;
>> +	struct device *dev = &pdev->dev;
>> +	struct resource *atu_dma_res;
>> +	struct tegra_pcie_dw *pcie;
>> +	struct resource *dbi_res;
>> +	struct pcie_port *pp;
>> +	struct dw_pcie *pci;
>> +	struct phy **phys;
>> +	char *name;
>> +	int ret;
>> +	u32 i;
>> +
>> +	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
>> +	if (!pcie)
>> +		return -ENOMEM;
>> +
>> +	pci = &pcie->pci;
>> +	pci->dev = &pdev->dev;
>> +	pci->ops = &tegra_dw_pcie_ops;
>> +	pp = &pci->pp;
>> +	pcie->dev = &pdev->dev;
>> +
>> +	data = (struct tegra_pcie_soc *)of_device_get_match_data(dev);
>> +	if (!data)
>> +		return -EINVAL;
>> +	pcie->mode = (enum dw_pcie_device_mode)data->mode;
>> +
>> +	ret = tegra_pcie_dw_parse_dt(pcie);
>> +	if (ret < 0) {
>> +		dev_err(pcie->dev, "Failed to parse device tree: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	pcie->pex_ctl_supply = devm_regulator_get(dev, "vddio-pex-ctl");
>> +	if (IS_ERR(pcie->pex_ctl_supply)) {
>> +		dev_err(dev, "Failed to get regulator: %ld\n",
>> +			PTR_ERR(pcie->pex_ctl_supply));
>> +		return PTR_ERR(pcie->pex_ctl_supply);
>> +	}
>> +
>> +	pcie->core_clk = devm_clk_get(dev, "core");
>> +	if (IS_ERR(pcie->core_clk)) {
>> +		dev_err(dev, "Failed to get core clock\n");
>> +		return PTR_ERR(pcie->core_clk);
>> +	}
>> +
>> +	pcie->appl_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>> +						      "appl");
>> +	if (!pcie->appl_res) {
>> +		dev_err(dev, "Failed to find \"appl\" region\n");
>> +		return PTR_ERR(pcie->appl_res);
>> +	}
>> +	pcie->appl_base = devm_ioremap_resource(dev, pcie->appl_res);
>> +	if (IS_ERR(pcie->appl_base)) {
>> +		dev_err(dev, "Failed to map \"appl\" region\n");
>> +		return PTR_ERR(pcie->appl_base);
>> +	}
>> +
>> +	pcie->core_apb_rst = devm_reset_control_get(pcie->dev, "core_apb");
>> +	if (IS_ERR(pcie->core_apb_rst)) {
>> +		dev_err(pcie->dev, "Failed to get core_apb reset\n");
>> +		return PTR_ERR(pcie->core_apb_rst);
>> +	}
>> +
>> +	phys = devm_kcalloc(pcie->dev, pcie->phy_count, sizeof(*phys),
>> +			    GFP_KERNEL);
>> +	if (!phys)
>> +		return PTR_ERR(phys);
>> +
>> +	for (i = 0; i < pcie->phy_count; i++) {
>> +		name = kasprintf(GFP_KERNEL, "p2u-%u", i);
>> +		if (!name) {
>> +			dev_err(pcie->dev, "Failed to create P2U string\n");
>> +			return -ENOMEM;
>> +		}
>> +		phys[i] = devm_phy_get(pcie->dev, name);
>> +		kfree(name);
>> +		if (IS_ERR(phys[i])) {
>> +			ret = PTR_ERR(phys[i]);
>> +			dev_err(pcie->dev, "Failed to get phy: %d\n", ret);
> 
> s/phy/PHY/
Done.

> 
>> +			return ret;
>> +		}
>> +	}
>> +
>> +	pcie->phys = phys;
>> +
>> +	dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
>> +	if (!dbi_res) {
>> +		dev_err(dev, "Failed to find \"dbi\" region\n");
> 
> No need to print this error message...
> 
>> +		return PTR_ERR(dbi_res);
>> +	}
>> +	pcie->dbi_res = dbi_res;
>> +
>> +	pci->dbi_base = devm_ioremap_resource(dev, dbi_res);
>> +	if (IS_ERR(pci->dbi_base)) {
>> +		dev_err(dev, "Failed to map \"dbi\" region\n");
> 
> ... or this one. devm_ioremap_resource() already prints them.
Done.

> 
>> +		return PTR_ERR(pci->dbi_base);
>> +	}
>> +
>> +	/* Tegra HW locates DBI2 at a fixed offset from DBI */
>> +	pci->dbi_base2 = pci->dbi_base + 0x1000;
>> +
>> +	atu_dma_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>> +						   "atu_dma");
>> +	if (!atu_dma_res) {
>> +		dev_err(dev, "Failed to find \"atu_dma\" region\n");
>> +		return PTR_ERR(atu_dma_res);
>> +	}
>> +	pcie->atu_dma_res = atu_dma_res;
>> +	pci->atu_base = devm_ioremap_resource(dev, atu_dma_res);
>> +	if (IS_ERR(pci->atu_base)) {
>> +		dev_err(dev, "Failed to map \"atu_dma\" region\n");
>> +		return PTR_ERR(pci->atu_base);
>> +	}
>> +
>> +	pcie->core_rst = devm_reset_control_get(pcie->dev, "core");
>> +	if (IS_ERR(pcie->core_rst)) {
>> +		dev_err(pcie->dev, "Failed to get core reset\n");
>> +		return PTR_ERR(pcie->core_rst);
>> +	}
>> +
>> +	pp->irq = platform_get_irq_byname(pdev, "intr");
>> +	if (!pp->irq) {
>> +		dev_err(pcie->dev, "Failed to get \"intr\" interrupt\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	ret = devm_request_irq(dev, pp->irq, tegra_pcie_irq_handler,
>> +			       IRQF_SHARED, "tegra-pcie-intr", pcie);
>> +	if (ret) {
>> +		dev_err(pcie->dev, "Failed to request IRQ %d: %d\n", pp->irq,
>> +			ret);
>> +		return ret;
>> +	}
>> +
>> +	pcie->bpmp = tegra_bpmp_get(pcie->dev);
>> +	if (IS_ERR(pcie->bpmp))
>> +		return PTR_ERR(pcie->bpmp);
>> +
>> +	platform_set_drvdata(pdev, pcie);
>> +
>> +	if (pcie->mode == DW_PCIE_RC_TYPE) {
>> +		ret = tegra_pcie_config_rp(pcie);
>> +		if (ret && ret != -ENOMEDIUM)
>> +			goto fail;
>> +		else
>> +			return 0;
>> +	}
>> +
>> +fail:
>> +	tegra_bpmp_put(pcie->bpmp);
>> +	return ret;
>> +}
>> +
>> +static int tegra_pcie_dw_remove(struct platform_device *pdev)
>> +{
>> +	struct tegra_pcie_dw *pcie = platform_get_drvdata(pdev);
>> +
>> +	if (pcie->mode != DW_PCIE_RC_TYPE)
>> +		return 0;
>> +
>> +	if (!pcie->link_state)
>> +		return 0;
>> +
>> +	debugfs_remove_recursive(pcie->debugfs);
>> +	tegra_pcie_deinit_controller(pcie);
>> +	pm_runtime_put_sync(pcie->dev);
>> +	pm_runtime_disable(pcie->dev);
>> +	tegra_bpmp_put(pcie->bpmp);
>> +
>> +	return 0;
>> +}
>> +
>> +static int tegra_pcie_dw_suspend_late(struct device *dev)
>> +{
>> +	struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
>> +	u32 val;
>> +
>> +	if (!pcie->link_state)
>> +		return 0;
>> +
>> +	/* Enable HW_HOT_RST mode */
>> +	val = readl(pcie->appl_base + APPL_CTRL);
>> +	val &= ~(APPL_CTRL_HW_HOT_RST_MODE_MASK <<
>> +		  APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
>> +	val |= APPL_CTRL_HW_HOT_RST_EN;
>> +	writel(val, pcie->appl_base + APPL_CTRL);
>> +
>> +	return 0;
>> +}
>> +
>> +static int tegra_pcie_dw_suspend_noirq(struct device *dev)
>> +{
>> +	struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
>> +
>> +	if (!pcie->link_state)
>> +		return 0;
>> +
>> +	/* Save MSI interrupt vector */
>> +	pcie->msi_ctrl_int = dw_pcie_readl_dbi(&pcie->pci,
>> +					       PORT_LOGIC_MSI_CTRL_INT_0_EN);
>> +	tegra_pcie_downstream_dev_to_D0(pcie);
>> +	tegra_pcie_dw_pme_turnoff(pcie);
>> +	return __deinit_controller(pcie);
>> +}
>> +
>> +static int tegra_pcie_dw_resume_noirq(struct device *dev)
>> +{
>> +	struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
>> +	int ret;
>> +
>> +	if (!pcie->link_state)
>> +		return 0;
>> +
>> +	ret = tegra_pcie_config_controller(pcie, true);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = tegra_pcie_dw_host_init(&pcie->pci.pp);
>> +	if (ret < 0) {
>> +		dev_err(dev, "Failed to init host: %d\n", ret);
>> +		goto fail_host_init;
>> +	}
>> +
>> +	/* Restore MSI interrupt vector */
>> +	dw_pcie_writel_dbi(&pcie->pci, PORT_LOGIC_MSI_CTRL_INT_0_EN,
>> +			   pcie->msi_ctrl_int);
>> +
>> +	return 0;
>> +fail_host_init:
>> +	return __deinit_controller(pcie);
>> +}
>> +
>> +static int tegra_pcie_dw_resume_early(struct device *dev)
>> +{
>> +	struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
>> +	u32 val;
>> +
>> +	if (!pcie->link_state)
>> +		return 0;
>> +
>> +	/* Disable HW_HOT_RST mode */
>> +	val = readl(pcie->appl_base + APPL_CTRL);
>> +	val &= ~(APPL_CTRL_HW_HOT_RST_MODE_MASK <<
>> +		  APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
>> +	val |= APPL_CTRL_HW_HOT_RST_MODE_IMDT_RST <<
>> +		APPL_CTRL_HW_HOT_RST_MODE_SHIFT;
>> +	val &= ~APPL_CTRL_HW_HOT_RST_EN;
>> +	writel(val, pcie->appl_base + APPL_CTRL);
>> +
>> +	return 0;
>> +}
>> +
>> +static void tegra_pcie_dw_shutdown(struct platform_device *pdev)
>> +{
>> +	struct tegra_pcie_dw *pcie = platform_get_drvdata(pdev);
>> +
>> +	if (pcie->mode != DW_PCIE_RC_TYPE)
>> +		return;
>> +
>> +	if (!pcie->link_state)
>> +		return;
>> +
>> +	debugfs_remove_recursive(pcie->debugfs);
>> +	tegra_pcie_downstream_dev_to_D0(pcie);
>> +
>> +	disable_irq(pcie->pci.pp.irq);
>> +	if (IS_ENABLED(CONFIG_PCI_MSI))
>> +		disable_irq(pcie->pci.pp.msi_irq);
>> +
>> +	tegra_pcie_dw_pme_turnoff(pcie);
>> +	__deinit_controller(pcie);
>> +}
>> +
>> +static const struct dev_pm_ops tegra_pcie_dw_pm_ops = {
>> +	.suspend_late = tegra_pcie_dw_suspend_late,
>> +	.suspend_noirq = tegra_pcie_dw_suspend_noirq,
>> +	.resume_noirq = tegra_pcie_dw_resume_noirq,
>> +	.resume_early = tegra_pcie_dw_resume_early,
>> +};
>> +
>> +static struct platform_driver tegra_pcie_dw_driver = {
>> +	.probe = tegra_pcie_dw_probe,
>> +	.remove = tegra_pcie_dw_remove,
>> +	.shutdown = tegra_pcie_dw_shutdown,
>> +	.driver = {
>> +		.name	= "tegra194-pcie",
>> +#ifdef CONFIG_PM
>> +		.pm = &tegra_pcie_dw_pm_ops,
>> +#endif
> 
> No need for the preprocessor conditional. 64-bit Tegra always has PM
> enabled these days.
Done.

> 
>> +		.of_match_table = tegra_pcie_dw_of_match,
>> +	},
>> +};
>> +module_platform_driver(tegra_pcie_dw_driver);
>> +
>> +MODULE_AUTHOR("Vidya Sagar <vidyas@nvidia.com>");
>> +MODULE_DESCRIPTION("NVIDIA PCIe host controller driver");
>> +MODULE_LICENSE("GPL v2");
>> -- 
>> 2.17.1
>>
> 
> Thierry
>