Re: [PATCH v7 2/3] dwc: PCI: intel: PCIe RC controller driver

From: Dilip Kota
Date: Mon Nov 18 2019 - 03:24:40 EST



On 11/15/2019 6:19 PM, Andy Shevchenko wrote:
On Fri, Nov 15, 2019 at 10:30:43AM +0800, Dilip Kota wrote:
Add support to PCIe RC controller on Intel Gateway SoCs.
PCIe controller is based of Synopsys DesignWare PCIe core.

Intel PCIe driver requires Upconfigure support, Fast Training
Sequence and link speed configurations. So adding the respective
helper functions in the PCIe DesignWare framework.
It also programs hardware autonomous speed during speed
configuration so defining it in pci_regs.h.
FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>

Although few nitpicks below.
Thanks Andy for reviewing the patch.

Signed-off-by: Dilip Kota <eswara.kota@xxxxxxxxxxxxxxx>
Reviewed-by: Andrew Murray <andrew.murray@xxxxxxx>
Acked-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
---
Changes on v7:
Add Acked-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
Remove unused header files.
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>

Changes on v6:
Add Reviewed-by: Andrew Murray <andrew.murray@xxxxxxx>
Address review comments:
Remove extra space in Kconfig
Fix style indents in switch case
Apply mask for the n_fts argument in dw_pcie_link_set_n_fts()
to prevent the case of n_fts value having outside the mask bits
Update PORT_LOGIC_N_FTS to PORT_LOGIC_N_FTS_MASK
Update BUS_IATU_OFFS to BUS_IATU_OFFSET
Update RST_INTRVL_DFT_MS to RESET_INTERVAL_MS
Reduce local variables in pcie_update_bits()
Remove blank lines
Remove extra paranthesis during readl_poll_timeout() call
Add error handling for dw_pcie_find_capability() call
Add blank line before dev_info() in probe()

Changes on v5:
Use new, old variables in pcie_update_bits()
Correct naming:
s/Designware/DesignWare
s/pcie/PCIe
s/pci/PCI
s/Hw/HW
Upconfig to Upconfigure
Remove extra lines after the intel_pcie_max_speed_setup() def.
Use pcie_link_speed[] and remove enum for pcie gen.
Remove dw_pcie_link_speed_change() def.
Remove "linux,pci-domain" parsing.
Remove 'id' variable in intel_pcie_port structure.
Remove extra spaces for lpp->link_gen =
Correct the offset of PCI_EXP_LNKCTL2_HASD to 0x0020.
Remove programming of RCB and CCC bits in PCI_EXP_LCTL reg.
Remove programming Slot clock cfg in PCI_EXP_LSTS reg.
Update the comments at num_viewport setting.
Update the description in Kconfig.
Get PCIe cap offset from the registers using dw_pcie_find_capability()
Define pcie_cap_ofst var in intel_pcie_port struct to store the same.
Remove the PCIE_CAP_OFST macro.
Move intel_pcie_max_speed_setup() function to DesignWare framework,
defined as dw_pcie_link_set_max_speed()
Set EXPORT_SYMBOL_GPL for the newer functions defined in
pcie-designware.c

Changes on v4:
Rename the driver naming and description to
"PCIe RC controller on Intel Gateway SoCs".
Use PCIe core register macros defined in pci_regs.h
and remove respective local definitions.
Remove PCIe core interrupt handling.
Move PCIe link control speed change, upconfig and FTS.
configuration functions to DesignWare framework.
Use of_pci_get_max_link_speed().
Mark dependency on X86 and COMPILE_TEST in Kconfig.
Remove lanes and add n_fts variables in intel_pcie_port structure.
Rename rst_interval variable to rst_intrvl in intel_pcie_port structure.
Remove intel_pcie_mem_iatu() as it is already perfomed in dw_setup_rc()
Move sysfs attributes specific code to separate patch.
Remove redundant error handling.
Reduce LoCs by doing variable initializations while declaration itself.
Add extra line after closing parenthesis.
Move intel_pcie_ep_rst_init() out of get_resources()

changes on v3:
Rename PCIe app logic registers with PCIE_APP prefix.
PCIE_IOP_CTRL configuration is not required. Remove respective code.
Remove wrapper functions for clk enable/disable APIs.
Use platform_get_resource_byname() instead of
devm_platform_ioremap_resource() to be similar with DWC framework.
Rename phy name to "pciephy".
Modify debug message in msi_init() callback to be more specific.
Remove map_irq() callback.
Enable the INTx interrupts at the time of PCIe initialization.
Reduce memory fragmentation by using variable "struct dw_pcie pci"
instead of allocating memory.
Reduce the delay to 100us during enpoint initialization
intel_pcie_ep_rst_init().
Call dw_pcie_host_deinit() during remove() instead of directly
calling PCIe core APIs.
Rename "intel,rst-interval" to "reset-assert-ms".
Remove unused APP logic Interrupt bit macro definitions.
Use dwc framework's dw_pcie_setup_rc() for PCIe host specific
configuration instead of redefining the same functionality in
the driver.
Move the whole DT parsing specific code to intel_pcie_get_resources()

drivers/pci/controller/dwc/Kconfig | 10 +
drivers/pci/controller/dwc/Makefile | 1 +
drivers/pci/controller/dwc/pcie-designware.c | 57 +++
drivers/pci/controller/dwc/pcie-designware.h | 12 +
drivers/pci/controller/dwc/pcie-intel-gw.c | 542 +++++++++++++++++++++++++++
include/uapi/linux/pci_regs.h | 1 +
6 files changed, 623 insertions(+)
create mode 100644 drivers/pci/controller/dwc/pcie-intel-gw.c

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 0ba988b5b5bc..fb6d474477df 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -82,6 +82,16 @@ config PCIE_DW_PLAT_EP
order to enable device-specific features PCI_DW_PLAT_EP must be
selected.
+config PCIE_INTEL_GW
+ bool "Intel Gateway PCIe host controller support"
+ depends on OF && (X86 || COMPILE_TEST)
+ select PCIE_DW_HOST
+ help
+ Say 'Y' here to enable PCIe Host controller support on Intel
+ Gateway SoCs.
+ The PCIe controller uses the DesignWare core plus Intel-specific
+ hardware wrappers.
+
config PCI_EXYNOS
bool "Samsung Exynos PCIe controller"
depends on SOC_EXYNOS5440 || COMPILE_TEST
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index b30336181d46..99db83cd2f35 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -3,6 +3,7 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o
obj-$(CONFIG_PCIE_DW_HOST) += pcie-designware-host.o
obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o
obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
+obj-$(CONFIG_PCIE_INTEL_GW) += pcie-intel-gw.o
obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 820488dfeaed..479e250695a0 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -14,6 +14,8 @@
#include "pcie-designware.h"
+extern const unsigned char pcie_link_speed[];
+
/*
* These interfaces resemble the pci_find_*capability() interfaces, but these
* are for configuring host controllers, which are bridges *to* PCI devices but
@@ -474,6 +476,61 @@ int dw_pcie_link_up(struct dw_pcie *pci)
(!(val & PCIE_PORT_DEBUG1_LINK_IN_TRAINING)));
}
+void dw_pcie_upconfig_setup(struct dw_pcie *pci)
+{
+ u32 val;
+
+ val = dw_pcie_readl_dbi(pci, PCIE_PORT_MULTI_LANE_CTRL);
+ val |= PORT_MLTI_UPCFG_SUPPORT;
+ dw_pcie_writel_dbi(pci, PCIE_PORT_MULTI_LANE_CTRL, val);
+}
+EXPORT_SYMBOL_GPL(dw_pcie_upconfig_setup);
+
+void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen)
+{
+ u32 reg, val;
+ u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+
+ reg = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCTL2);
+ reg &= ~PCI_EXP_LNKCTL2_TLS;
+
+ switch (pcie_link_speed[link_gen]) {
+ case PCIE_SPEED_2_5GT:
+ reg |= PCI_EXP_LNKCTL2_TLS_2_5GT;
+ break;
+ case PCIE_SPEED_5_0GT:
+ reg |= PCI_EXP_LNKCTL2_TLS_5_0GT;
+ break;
+ case PCIE_SPEED_8_0GT:
+ reg |= PCI_EXP_LNKCTL2_TLS_8_0GT;
+ break;
+ case PCIE_SPEED_16_0GT:
+ reg |= PCI_EXP_LNKCTL2_TLS_16_0GT;
+ break;
+ default:
+ /* Use hardware capability */
+ val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
+ val = FIELD_GET(PCI_EXP_LNKCAP_SLS, val);
+ reg &= ~PCI_EXP_LNKCTL2_HASD;
+ reg |= FIELD_PREP(PCI_EXP_LNKCTL2_TLS, val);
+ break;
+ }
+
+ dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCTL2, reg);
+}
+EXPORT_SYMBOL_GPL(dw_pcie_link_set_max_speed);
+
+void dw_pcie_link_set_n_fts(struct dw_pcie *pci, u32 n_fts)
+{
+ u32 val;
+
+ val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
+ val &= ~PORT_LOGIC_N_FTS_MASK;
+ val |= n_fts & PORT_LOGIC_N_FTS_MASK;
+ dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val);
+}
+EXPORT_SYMBOL_GPL(dw_pcie_link_set_n_fts);
+
static u8 dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci)
{
u32 val;
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 5a18e94e52c8..3b0be5cd9235 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -30,7 +30,12 @@
#define LINK_WAIT_IATU 9
/* Synopsys-specific PCIe configuration registers */
+#define PCIE_PORT_AFR 0x70C
+#define PORT_AFR_N_FTS_MASK GENMASK(15, 8)
+#define PORT_AFR_CC_N_FTS_MASK GENMASK(23, 16)
+
#define PCIE_PORT_LINK_CONTROL 0x710
+#define PORT_LINK_DLL_LINK_EN BIT(5)
#define PORT_LINK_MODE_MASK GENMASK(21, 16)
#define PORT_LINK_MODE(n) FIELD_PREP(PORT_LINK_MODE_MASK, n)
#define PORT_LINK_MODE_1_LANES PORT_LINK_MODE(0x1)
@@ -46,6 +51,7 @@
#define PCIE_PORT_DEBUG1_LINK_IN_TRAINING BIT(29)
#define PCIE_LINK_WIDTH_SPEED_CONTROL 0x80C
+#define PORT_LOGIC_N_FTS_MASK GENMASK(7, 0)
#define PORT_LOGIC_SPEED_CHANGE BIT(17)
#define PORT_LOGIC_LINK_WIDTH_MASK GENMASK(12, 8)
#define PORT_LOGIC_LINK_WIDTH(n) FIELD_PREP(PORT_LOGIC_LINK_WIDTH_MASK, n)
@@ -60,6 +66,9 @@
#define PCIE_MSI_INTR0_MASK 0x82C
#define PCIE_MSI_INTR0_STATUS 0x830
+#define PCIE_PORT_MULTI_LANE_CTRL 0x8C0
+#define PORT_MLTI_UPCFG_SUPPORT BIT(7)
+
#define PCIE_ATU_VIEWPORT 0x900
#define PCIE_ATU_REGION_INBOUND BIT(31)
#define PCIE_ATU_REGION_OUTBOUND 0
@@ -273,6 +282,9 @@ void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val);
u32 dw_pcie_read_atu(struct dw_pcie *pci, u32 reg, size_t size);
void dw_pcie_write_atu(struct dw_pcie *pci, u32 reg, size_t size, u32 val);
int dw_pcie_link_up(struct dw_pcie *pci);
+void dw_pcie_upconfig_setup(struct dw_pcie *pci);
+void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen);
+void dw_pcie_link_set_n_fts(struct dw_pcie *pci, u32 n_fts);
int dw_pcie_wait_for_link(struct dw_pcie *pci);
void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index,
int type, u64 cpu_addr, u64 pci_addr,
diff --git a/drivers/pci/controller/dwc/pcie-intel-gw.c b/drivers/pci/controller/dwc/pcie-intel-gw.c
new file mode 100644
index 000000000000..cd000cd5bed7
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-intel-gw.c
@@ -0,0 +1,542 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Intel Gateway SoCs
+ *
+ * Copyright (c) 2019 Intel Corporation.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iopoll.h>
+#include <linux/pci_regs.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#include "../../pci.h"
+#include "pcie-designware.h"
+
+#define PORT_AFR_N_FTS_GEN12_DFT (SZ_128 - 1)
+#define PORT_AFR_N_FTS_GEN3 180
+#define PORT_AFR_N_FTS_GEN4 196
+
+/* PCIe Application logic Registers */
+#define PCIE_APP_CCR 0x10
+#define PCIE_APP_CCR_LTSSM_ENABLE BIT(0)
+
+#define PCIE_APP_MSG_CR 0x30
+#define PCIE_APP_MSG_XMT_PM_TURNOFF BIT(0)
+
+#define PCIE_APP_PMC 0x44
+#define PCIE_APP_PMC_IN_L2 BIT(20)
+
+#define PCIE_APP_IRNEN 0xF4
+#define PCIE_APP_IRNCR 0xF8
+#define PCIE_APP_IRN_AER_REPORT BIT(0)
+#define PCIE_APP_IRN_PME BIT(2)
+#define PCIE_APP_IRN_RX_VDM_MSG BIT(4)
+#define PCIE_APP_IRN_PM_TO_ACK BIT(9)
+#define PCIE_APP_IRN_LINK_AUTO_BW_STAT BIT(11)
+#define PCIE_APP_IRN_BW_MGT BIT(12)
+#define PCIE_APP_IRN_MSG_LTR BIT(18)
+#define PCIE_APP_IRN_SYS_ERR_RC BIT(29)
+#define PCIE_APP_INTX_OFST 12
+
+#define PCIE_APP_IRN_INT \
+ (PCIE_APP_IRN_AER_REPORT | PCIE_APP_IRN_PME | \
+ PCIE_APP_IRN_RX_VDM_MSG | PCIE_APP_IRN_SYS_ERR_RC | \
+ PCIE_APP_IRN_PM_TO_ACK | PCIE_APP_IRN_MSG_LTR | \
+ PCIE_APP_IRN_BW_MGT | PCIE_APP_IRN_LINK_AUTO_BW_STAT | \
+ (PCIE_APP_INTX_OFST + PCI_INTERRUPT_INTA) | \
+ (PCIE_APP_INTX_OFST + PCI_INTERRUPT_INTB) | \
+ (PCIE_APP_INTX_OFST + PCI_INTERRUPT_INTC) | \
+ (PCIE_APP_INTX_OFST + PCI_INTERRUPT_INTD))
These can be shifted left by two TABs.
Ok, will fix them in next patch revision.

+
+#define BUS_IATU_OFFSET SZ_256M
+#define RESET_INTERVAL_MS 100
+
+struct intel_pcie_soc {
+ unsigned int pcie_ver;
+ unsigned int pcie_atu_offset;
+ u32 num_viewport;
+};
+
+struct intel_pcie_port {
+ struct dw_pcie pci;
+ void __iomem *app_base;
+ struct gpio_desc *reset_gpio;
+ u32 rst_intrvl;
+ u32 max_speed;
+ u32 link_gen;
+ u32 max_width;
+ u32 n_fts;
+ struct clk *core_clk;
+ struct reset_control *core_rst;
+ struct phy *phy;
+ u8 pcie_cap_ofst;
+};
+
+static void pcie_update_bits(void __iomem *base, u32 mask, u32 val, u32 ofs)
More logical ordering of the parameters will be base, offset, mask, value.
Agree, will fix it in next patch revision.

+{
+ u32 old;
+
+ old = readl(base + ofs);
+ val = (old & ~mask) | (val & mask);
+
+ if (val != old)
+ writel(val, base + ofs);
+}
+
+static inline u32 pcie_app_rd(struct intel_pcie_port *lpp, u32 ofs)
+{
+ return readl(lpp->app_base + ofs);
+}
+
+static inline void pcie_app_wr(struct intel_pcie_port *lpp, u32 val, u32 ofs)
Ditto.
Agree, will fix it in next patch revision.

+{
+ writel(val, lpp->app_base + ofs);
+}
+
+static void pcie_app_wr_mask(struct intel_pcie_port *lpp,
+ u32 mask, u32 val, u32 ofs)
Ditto.
Agree, will fix it in next patch revision.

+{
+ pcie_update_bits(lpp->app_base, mask, val, ofs);
+}
+
+static inline u32 pcie_rc_cfg_rd(struct intel_pcie_port *lpp, u32 ofs)
+{
+ return dw_pcie_readl_dbi(&lpp->pci, ofs);
+}
+
+static inline void pcie_rc_cfg_wr(struct intel_pcie_port *lpp, u32 val, u32 ofs)
Ditto.
Agree, will fix it in next patch revision.

+{
+ dw_pcie_writel_dbi(&lpp->pci, ofs, val);
+}
+
+static void pcie_rc_cfg_wr_mask(struct intel_pcie_port *lpp,
+ u32 mask, u32 val, u32 ofs)
Ditto.
Agree, will fix it in next patch revision.

+{
+ pcie_update_bits(lpp->pci.dbi_base, mask, val, ofs);
+}
+
+static void intel_pcie_ltssm_enable(struct intel_pcie_port *lpp)
+{
+ pcie_app_wr_mask(lpp, PCIE_APP_CCR_LTSSM_ENABLE,
+ PCIE_APP_CCR_LTSSM_ENABLE, PCIE_APP_CCR);
+}
+
+static void intel_pcie_ltssm_disable(struct intel_pcie_port *lpp)
+{
+ pcie_app_wr_mask(lpp, PCIE_APP_CCR_LTSSM_ENABLE, 0, PCIE_APP_CCR);
+}
+
+static void intel_pcie_link_setup(struct intel_pcie_port *lpp)
+{
+ u32 val;
+ u8 offset = lpp->pcie_cap_ofst;
+
+ val = pcie_rc_cfg_rd(lpp, offset + PCI_EXP_LNKCAP);
+ lpp->max_speed = FIELD_GET(PCI_EXP_LNKCAP_SLS, val);
+ lpp->max_width = FIELD_GET(PCI_EXP_LNKCAP_MLW, val);
+
+ val = pcie_rc_cfg_rd(lpp, offset + PCI_EXP_LNKCTL);
+
+ val &= ~(PCI_EXP_LNKCTL_LD | PCI_EXP_LNKCTL_ASPMC);
+ pcie_rc_cfg_wr(lpp, val, offset + PCI_EXP_LNKCTL);
+}
+
+static void intel_pcie_port_logic_setup(struct intel_pcie_port *lpp)
+{
+ u32 val, mask;
+
+ switch (pcie_link_speed[lpp->max_speed]) {
+ case PCIE_SPEED_8_0GT:
+ lpp->n_fts = PORT_AFR_N_FTS_GEN3;
+ break;
+ case PCIE_SPEED_16_0GT:
+ lpp->n_fts = PORT_AFR_N_FTS_GEN4;
+ break;
+ default:
+ lpp->n_fts = PORT_AFR_N_FTS_GEN12_DFT;
+ break;
+ }
+
+ mask = PORT_AFR_N_FTS_MASK | PORT_AFR_CC_N_FTS_MASK;
+ val = FIELD_PREP(PORT_AFR_N_FTS_MASK, lpp->n_fts) |
+ FIELD_PREP(PORT_AFR_CC_N_FTS_MASK, lpp->n_fts);
+ pcie_rc_cfg_wr_mask(lpp, mask, val, PCIE_PORT_AFR);
+
+ /* Port Link Control Register */
+ pcie_rc_cfg_wr_mask(lpp, PORT_LINK_DLL_LINK_EN,
+ PORT_LINK_DLL_LINK_EN, PCIE_PORT_LINK_CONTROL);
+}
+
+static void intel_pcie_rc_setup(struct intel_pcie_port *lpp)
+{
+ intel_pcie_ltssm_disable(lpp);
+ intel_pcie_link_setup(lpp);
+ dw_pcie_setup_rc(&lpp->pci.pp);
+ dw_pcie_upconfig_setup(&lpp->pci);
+ intel_pcie_port_logic_setup(lpp);
+ dw_pcie_link_set_max_speed(&lpp->pci, lpp->link_gen);
+ dw_pcie_link_set_n_fts(&lpp->pci, lpp->n_fts);
+}
+
+static int intel_pcie_ep_rst_init(struct intel_pcie_port *lpp)
+{
+ struct device *dev = lpp->pci.dev;
+ int ret;
+
+ lpp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(lpp->reset_gpio)) {
+ ret = PTR_ERR(lpp->reset_gpio);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to request PCIe GPIO: %d\n", ret);
+ return ret;
+ }
+
+ /* Make initial reset last for 100us */
+ usleep_range(100, 200);
+
+ return 0;
+}
+
+static void intel_pcie_core_rst_assert(struct intel_pcie_port *lpp)
+{
+ reset_control_assert(lpp->core_rst);
+}
+
+static void intel_pcie_core_rst_deassert(struct intel_pcie_port *lpp)
+{
+ /*
+ * One micro-second delay to make sure the reset pulse
+ * wide enough so that core reset is clean.
+ */
+ udelay(1);
+ reset_control_deassert(lpp->core_rst);
+
+ /*
+ * Some SoC core reset also reset PHY, more delay needed
+ * to make sure the reset process is done.
+ */
+ usleep_range(1000, 2000);
+}
+
+static void intel_pcie_device_rst_assert(struct intel_pcie_port *lpp)
+{
+ gpiod_set_value_cansleep(lpp->reset_gpio, 1);
+}
+
+static void intel_pcie_device_rst_deassert(struct intel_pcie_port *lpp)
+{
+ msleep(lpp->rst_intrvl);
+ gpiod_set_value_cansleep(lpp->reset_gpio, 0);
+}
+
+static int intel_pcie_app_logic_setup(struct intel_pcie_port *lpp)
+{
+ intel_pcie_device_rst_deassert(lpp);
+ intel_pcie_ltssm_enable(lpp);
+
+ return dw_pcie_wait_for_link(&lpp->pci);
+}
+
+static void intel_pcie_core_irq_disable(struct intel_pcie_port *lpp)
+{
+ pcie_app_wr(lpp, 0, PCIE_APP_IRNEN);
+ pcie_app_wr(lpp, PCIE_APP_IRN_INT, PCIE_APP_IRNCR);
+}
+
+static int intel_pcie_get_resources(struct platform_device *pdev)
+{
+ struct intel_pcie_port *lpp = platform_get_drvdata(pdev);
+ struct dw_pcie *pci = &lpp->pci;
+ struct device *dev = pci->dev;
+ struct resource *res;
+ int ret;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+ pci->dbi_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(pci->dbi_base))
+ return PTR_ERR(pci->dbi_base);
+
+ lpp->core_clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(lpp->core_clk)) {
+ ret = PTR_ERR(lpp->core_clk);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to get clks: %d\n", ret);
+ return ret;
+ }
+
+ lpp->core_rst = devm_reset_control_get(dev, NULL);
+ if (IS_ERR(lpp->core_rst)) {
+ ret = PTR_ERR(lpp->core_rst);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to get resets: %d\n", ret);
+ return ret;
+ }
+
+ ret = device_property_match_string(dev, "device_type", "pci");
+ if (ret) {
+ dev_err(dev, "failed to find pci device type: %d\n", ret);
+ return ret;
+ }
+
+ if (device_property_read_u32(dev, "reset-assert-ms", &lpp->rst_intrvl))
I would rather use above pattern, i.e.

ret = device_property_read_u32(...);
if (ret)
...
Ok, will update it in next patch revision.

+ lpp->rst_intrvl = RESET_INTERVAL_MS;
+
+ ret = of_pci_get_max_link_speed(dev->of_node);
+ lpp->link_gen = ret < 0 ? 0 : ret;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "app");
+ lpp->app_base = devm_ioremap_resource(dev, res);
This can use newly introduced (c9c8641d3ebd)
devm_platform_ioremap_resource_byname() API, however it will require PCI
to merge an immutable branch (if any) from driver core.
Who can help on merging the devm_platform_ioremap_byname patch!

Regards,
Dilip