[PATCH v4 0/4] PCI: st: provide support for dw pcie

[PATCH v4 0/4] PCI: st: provide support for dw pcie

[Gabriel Fernandez]

This patchset is based on v4.2-rc1 and is based on 
[PATCH v8 0/6] PCI: hisi: Add PCIe host support for HiSilicon SoC Hip05
patchset from Zhou Wang.

Changes in v4:
 - Remove pci: designware: remove my pci_common_init_dev() patch and
	use [PATCH v8 3/6] PCI: designware: Add ARM64 support instead.
	This patch is a good solution for me to disable IO support.
 - add __init to st_pcie_probe() and use module_init() instead
	device_initcall() to prevent the probe function from being
	deferred and to prevent module unloading.

Changes in v3:
 - Remove power management functions (was not fully tested)
 - Remove configuration space range from dt binding
 - Remove pci_common_init_dev() call in pcie-designware.c to avoid 
   default IO space declaration. 

Changes in v2:
 - comestic corrections in device tree binding
 - add pci-st.c into MAINTAINERS
 - remove st_pcie_ops structure to avoid another level of indirection
 - remove nasty busy-loop
 - remove useless test using virt_to_phys()
 - move disable io support into dw-pcie driver

I don't change the st_pcie_abort_handler() function because abort handling
is masked during boot.


This patch-set introduces a STMicroelectronics PCIe controller.
It's based on designware PCIe driver.

Gabriel Fernandez (4):
  ARM: STi: Kconfig update for PCIe support
  PCI: st: Add Device Tree bindings for sti pcie
  PCI: st: Provide support for the sti PCIe controller
  MAINTAINERS: Add pci-st.c to ARCH/STI architecture

 Documentation/devicetree/bindings/pci/st-pcie.txt |  53 ++
 MAINTAINERS                                       |   1 +
 arch/arm/mach-sti/Kconfig                         |   2 +
 drivers/pci/host/Kconfig                          |   9 +
 drivers/pci/host/Makefile                         |   1 +
 drivers/pci/host/pci-st.c                         | 583 ++++++++++++++++++++++
 6 files changed, 649 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/st-pcie.txt
 create mode 100644 drivers/pci/host/pci-st.c

-- 
1.9.1

[PATCH v4 1/4] ARM: STi: Kconfig update for PCIe support

[Gabriel Fernandez]

Update Kconfig:
- MIGHT_HAVE_PCI
- PCI_DOMAINS

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
---
 arch/arm/mach-sti/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/mach-sti/Kconfig b/arch/arm/mach-sti/Kconfig
index 125865d..5f99e93 100644
--- a/arch/arm/mach-sti/Kconfig
+++ b/arch/arm/mach-sti/Kconfig
@@ -9,6 +9,8 @@ menuconfig ARCH_STI
 	select ARCH_HAS_RESET_CONTROLLER
 	select HAVE_ARM_SCU if SMP
 	select ARCH_REQUIRE_GPIOLIB
+	select PCI_DOMAINS if PCI
+	select MIGHT_HAVE_PCI
 	select ARM_ERRATA_754322
 	select ARM_ERRATA_764369 if SMP
 	select ARM_ERRATA_775420
-- 
1.9.1

[PATCH v4 2/4] PCI: st: Add Device Tree bindings for sti pcie

[Gabriel Fernandez]

sti pcie is built around a Synopsis Designware PCIe IP.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
---
 Documentation/devicetree/bindings/pci/st-pcie.txt | 53 +++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/st-pcie.txt

diff --git a/Documentation/devicetree/bindings/pci/st-pcie.txt b/Documentation/devicetree/bindings/pci/st-pcie.txt
new file mode 100644
index 0000000..25fcab3
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/st-pcie.txt
@@ -0,0 +1,53 @@
+STMicroelectronics STi PCIe controller
+
+This PCIe host controller is based on the Synopsis Designware PCIe IP
+and thus inherits all the common properties defined in designware-pcie.txt.
+
+Required properties:
+ - compatible: "st,stih407-pcie"
+ - reg: base address and length of the pcie controller, mem-window address
+   and length available to the controller.
+ - interrupts: A list of interrupt outputs of the controller. Must contain an
+   entry for each entry in the interrupt-names property.
+ - interrupt-names: Should be "msi". STi interrupt that is asserted when an
+   MSI is received.
+ - st,syscfg : should be a phandle of the syscfg node. Also contains syscfg
+   offset for IP configuration.
+ - resets, reset-names: the power-down and soft-reset lines of PCIe IP.
+   Associated names must be "powerdown" and "softreset".
+ - phys, phy-names: the phandle for the PHY device.
+   Associated name must be "pcie"
+
+Optional properties:
+ - reset-gpio: a GPIO spec to define which pin is connected to the bus reset.
+
+Example:
+
+pcie0: pcie@9b00000 {
+	compatible = "st,pcie", "snps,dw-pcie";
+	device_type = "pci";
+	reg = <0x09b00000 0x4000>,	/* dbi cntrl registers */
+	      <0x2fff0000 0x00010000>,	/* configuration space */
+	      <0x40000000 0x80000000>;	/* lmi mem window */
+	reg-names = "dbi", "config", "mem-window";
+	st,syscfg = <&syscfg_core 0xd8 0xe0>;
+	#address-cells = <3>;
+	#size-cells = <2>;
+	ranges = <0x82000000 0 0x20000000 0x20000000 0 0x0FFF0000>; /* non-prefetchable memory */
+	num-lanes = <1>;
+	interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
+	interrupt-names = "msi";
+	#interrupt-cells = <1>;
+	interrupt-map-mask = <0 0 0 7>;
+	interrupt-map = <0 0 0 1 &intc GIC_SPI 160 IRQ_TYPE_LEVEL_HIGH>, /* INT A */
+			<0 0 0 2 &intc GIC_SPI 161 IRQ_TYPE_LEVEL_HIGH>, /* INT B */
+			<0 0 0 3 &intc GIC_SPI 162 IRQ_TYPE_LEVEL_HIGH>, /* INT C */
+			<0 0 0 4 &intc GIC_SPI 163 IRQ_TYPE_LEVEL_HIGH>; /* INT D */
+
+	resets = <&powerdown STIH407_PCIE0_POWERDOWN>,
+		 <&softreset STIH407_PCIE0_SOFTRESET>;
+	reset-names = "powerdown",
+		      "softreset";
+	phys = <&phy_port0 PHY_TYPE_PCIE>;
+	phy-names = "pcie";
+};
-- 
1.9.1

[PATCH v4 3/4] PCI: st: Provide support for the sti PCIe controller

[Gabriel Fernandez]

sti pcie is built around a Synopsis Designware PCIe IP.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
---
 drivers/pci/host/Kconfig  |   9 +
 drivers/pci/host/Makefile |   1 +
 drivers/pci/host/pci-st.c | 583 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 593 insertions(+)
 create mode 100644 drivers/pci/host/pci-st.c

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index c132bdd..db56b8f 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -145,4 +145,13 @@ config PCIE_IPROC_BCMA
 	  Say Y here if you want to use the Broadcom iProc PCIe controller
 	  through the BCMA bus interface
 
+config PCI_ST
+	bool "ST PCIe controller"
+	depends on ARCH_STI || (ARM && COMPILE_TEST)
+	select PCIE_DW
+	help
+	  Enable PCIe controller support on ST Socs. This controller is based
+	  on Designware hardware and therefore the driver re-uses the
+	  Designware core functions to implement the driver.
+
 endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 140d66f..c4024fa 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_PCI_VERSATILE) += pci-versatile.o
 obj-$(CONFIG_PCIE_IPROC) += pcie-iproc.o
 obj-$(CONFIG_PCIE_IPROC_PLATFORM) += pcie-iproc-platform.o
 obj-$(CONFIG_PCIE_IPROC_BCMA) += pcie-iproc-bcma.o
+obj-$(CONFIG_PCI_ST) += pci-st.o
diff --git a/drivers/pci/host/pci-st.c b/drivers/pci/host/pci-st.c
new file mode 100644
index 0000000..0e7aaa2
--- /dev/null
+++ b/drivers/pci/host/pci-st.c
@@ -0,0 +1,583 @@
+/*
+ * Copyright (C) 2014 STMicroelectronics
+ *
+ * STMicroelectronics PCI express Driver for sti SoCs.
+ * ST PCIe IPs are built around a Synopsys IP Core.
+ *
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_gpio.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/phy/phy.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#include "pcie-designware.h"
+
+#define TRANSLATION_CONTROL		0x900
+/* Controls if area is inclusive or exclusive */
+#define RC_PASS_ADDR_RANGE		BIT(1)
+
+/* Base of area reserved for config accesses. Fixed size of 64K. */
+#define CFG_BASE_ADDRESS		0x92c
+#define CFG_REGION_SIZE			65536
+#define CFG_SPACE1_OFFSET		0x1000
+
+/* First 4K of config space has this BDF (bus,device,function) */
+#define FUNC0_BDF_NUM			0x930
+
+/* Mem regions */
+#define IN0_MEM_ADDR_START		0x964
+#define IN0_MEM_ADDR_LIMIT		0x968
+#define IN1_MEM_ADDR_START		0x974
+#define IN1_MEM_ADDR_LIMIT		0x978
+
+/* This actually contains the LTSSM state machine state */
+#define PORT_LOGIC_DEBUG_REG_0		0x728
+
+/* LTSSM state machine values	*/
+#define DEBUG_REG_0_LTSSM_MASK		0x1f
+#define S_DETECT_QUIET			0x00
+#define S_DETECT_ACT			0x01
+#define S_POLL_ACTIVE			0x02
+#define S_POLL_COMPLIANCE		0x03
+#define S_POLL_CONFIG			0x04
+#define S_PRE_DETECT_QUIET		0x05
+#define S_DETECT_WAIT			0x06
+#define S_CFG_LINKWD_START		0x07
+#define S_CFG_LINKWD_ACEPT		0x08
+#define S_CFG_LANENUM_WAIT		0x09
+#define S_CFG_LANENUM_ACEPT		0x0A
+#define S_CFG_COMPLETE			0x0B
+#define S_CFG_IDLE			0x0C
+#define S_RCVRY_LOCK			0x0D
+#define S_RCVRY_SPEED			0x0E
+#define S_RCVRY_RCVRCFG			0x0F
+#define S_RCVRY_IDLE			0x10
+#define S_L0				0x11
+#define S_L0S				0x12
+#define S_L123_SEND_EIDLE		0x13
+#define S_L1_IDLE			0x14
+#define S_L2_IDLE			0x15
+#define S_L2_WAKE			0x16
+#define S_DISABLED_ENTRY		0x17
+#define S_DISABLED_IDLE			0x18
+#define S_DISABLED			0x19
+#define S_LPBK_ENTRY			0x1A
+#define S_LPBK_ACTIVE			0x1B
+#define S_LPBK_EXIT			0x1C
+#define S_LPBK_EXIT_TIMEOUT		0x1D
+#define S_HOT_RESET_ENTRY		0x1E
+#define S_HOT_RESET			0x1F
+
+/* syscfg bits */
+#define PCIE_SYS_INT			BIT(5)
+#define PCIE_APP_REQ_RETRY_EN		BIT(3)
+#define PCIE_APP_LTSSM_ENABLE		BIT(2)
+#define PCIE_APP_INIT_RST		BIT(1)
+#define PCIE_DEVICE_TYPE		BIT(0)
+#define PCIE_DEFAULT_VAL		PCIE_DEVICE_TYPE
+
+/* Time to wait between testing the link in msecs (hardware poll interval) */
+#define LINK_LOOP_DELAY_MS 1
+/* Total amount of time to wait for the link to come up in msecs */
+#define LINK_WAIT_MS 120
+#define LINK_LOOP_COUNT (LINK_WAIT_MS / LINK_LOOP_DELAY_MS)
+
+/* st,syscfg offsets */
+#define SYSCFG0_REG	1
+#define SYSCFG1_REG	2
+
+#define to_st_pcie(x)	container_of(x, struct st_pcie, pp)
+
+/**
+ * struct st_pcie - private data of the controller
+ * @pp: designware pcie port
+ * @syscfg0: PCIe configuration 0 register, regmap offset
+ * @syscfg1: PCIe configuration 1 register, regmap offset
+ * @phy: associated pcie phy
+ * @lmi: memory made available to the controller
+ * @regmap: Syscfg registers bank in which PCIe port is configured
+ * @pwr: power control
+ * @rst: reset control
+ * @reset_gpio: optional reset gpio
+ * @config_window_start: start address of 64K config space area
+ */
+struct st_pcie {
+	struct pcie_port pp;
+	int syscfg0;
+	int syscfg1;
+	struct phy *phy;
+	struct resource	*lmi;
+	struct regmap *regmap;
+	struct reset_control *pwr;
+	struct reset_control *rst;
+	int reset_gpio;
+	phys_addr_t config_window_start;
+};
+
+/*
+ * Function to test if the link is in an operational state or not. We must
+ * ensure the link is operational before we try to do a configuration access.
+ */
+static int st_pcie_link_up(struct pcie_port *pp)
+{
+	u32 status;
+	int link_up;
+	int count = 0;
+
+	/*
+	 * We have to be careful here. This is used in config read/write,
+	 * The higher levels switch off interrupts, so you cannot use
+	 * jiffies to do a timeout, or reschedule
+	 */
+	do {
+		/*
+		 * What about L2? I think software intervention is
+		 * required to get it out of L2, so in effect the link
+		 * is down. Requires more work when/if we implement power
+		 * management
+		 */
+		status = readl_relaxed(pp->dbi_base + PORT_LOGIC_DEBUG_REG_0);
+		status &= DEBUG_REG_0_LTSSM_MASK;
+
+		link_up = (status == S_L0) || (status == S_L0S) ||
+			  (status == S_L1_IDLE);
+
+		/*
+		 * It can take some considerable time for the link to actually
+		 * come up, caused by the PLLs. Experiments indicate it takes
+		 * about 8ms to actually bring the link up, but this can vary
+		 * considerably according to the specification. This code should
+		 * allow sufficient time
+		 */
+		if (!link_up)
+			mdelay(LINK_LOOP_DELAY_MS);
+
+	} while (!link_up && ++count < LINK_LOOP_COUNT);
+
+	return link_up;
+}
+
+/*
+ * On ARM platforms, we actually get a bus error returned when the PCIe IP
+ * returns a UR or CRS instead of an OK.
+ */
+static int st_pcie_abort_handler(unsigned long addr, unsigned int fsr,
+				 struct pt_regs *regs)
+{
+	return 0;
+}
+
+/*
+ * The PCI express core IP expects the following arrangement on it's address
+ * bus (slv_haddr) when driving config cycles.
+ * bus_number		[31:24]
+ * dev_number		[23:19]
+ * func_number		[18:16]
+ * unused		[15:12]
+ * ext_reg_number	[11:8]
+ * reg_number		[7:2]
+ *
+ * Bits [15:12] are unused.
+ *
+ * In the glue logic there is a 64K region of address space that can be
+ * written/read to generate config cycles. The base address of this is
+ * controlled by CFG_BASE_ADDRESS. There are 8 16 bit registers called
+ * FUNC0_BDF_NUM to FUNC8_BDF_NUM. These split the bottom half of the 64K
+ * window into 8 regions at 4K boundaries. These control the bus,device and
+ * function number you are trying to talk to.
+ *
+ * The decision on whether to generate a type 0 or type 1 access is controlled
+ * by bits 15:12 of the address you write to.  If they are zero, then a type 0
+ * is generated, if anything else it will be a type 1. Thus the bottom 4K
+ * region controlled by FUNC0_BDF_NUM can only generate type 0, all the others
+ * can only generate type 1.
+ *
+ * We only use FUNC0_BDF_NUM and FUNC1_BDF_NUM. Which one you use is selected
+ * by bit 12 of the address you write to. The selected register is then used
+ * for the top 16 bits of the slv_haddr to form the bus/dev/func, bit 15:12 are
+ * wired to zero, and bits 11:2 form the address of the register you want to
+ * read in config space.
+ *
+ * We always write FUNC0_BDF_NUM as a 32 bit write. So if we want type 1
+ * accesses we have to shift by 16 so in effect we are writing to FUNC1_BDF_NUM
+ */
+static inline u32 bdf_num(int bus, int devfn, int is_root_bus)
+{
+	return ((bus << 8) | devfn) << (is_root_bus ? 0 : 16);
+}
+
+static int st_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
+				 unsigned int devfn, int where, int size,
+				 u32 *val)
+{
+	int ret;
+	u32 bdf, addr;
+
+	addr = where & ~0x3;
+	bdf = bdf_num(bus->number, devfn, pci_is_root_bus(bus));
+
+	/* Set the config packet devfn */
+	writel_relaxed(bdf, pp->dbi_base + FUNC0_BDF_NUM);
+	readl_relaxed(pp->dbi_base + FUNC0_BDF_NUM);
+
+	if (bus->parent->number == pp->root_bus_nr)
+		ret = dw_pcie_cfg_read(pp->va_cfg0_base + addr, where, size,
+				       val);
+	else
+		ret = dw_pcie_cfg_read(pp->va_cfg1_base + addr, where, size,
+				       val);
+	return ret;
+}
+
+static int st_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
+				 unsigned int devfn, int where, int size,
+				 u32 val)
+{
+	int ret;
+	u32 bdf, addr;
+
+	addr = where & ~0x3;
+	bdf = bdf_num(bus->number, devfn, pci_is_root_bus(bus));
+
+	/* Set the config packet devfn */
+	writel_relaxed(bdf, pp->dbi_base + FUNC0_BDF_NUM);
+	readl_relaxed(pp->dbi_base + FUNC0_BDF_NUM);
+
+	if (bus->parent->number == pp->root_bus_nr)
+		ret = dw_pcie_cfg_write(pp->va_cfg0_base + addr, where, size,
+					val);
+	else
+		ret = dw_pcie_cfg_write(pp->va_cfg1_base + addr, where, size,
+					val);
+	return ret;
+}
+
+static void st_pcie_board_reset(struct pcie_port *pp)
+{
+	struct st_pcie *pcie = to_st_pcie(pp);
+
+	if (!gpio_is_valid(pcie->reset_gpio))
+		return;
+
+	if (gpio_direction_output(pcie->reset_gpio, 0)) {
+		dev_err(pp->dev, "Cannot set PERST# (gpio %u) to output\n",
+			pcie->reset_gpio);
+		return;
+	}
+
+	/* From PCIe spec */
+	msleep(2);
+	gpio_direction_output(pcie->reset_gpio, 1);
+
+	/*
+	 * PCIe specification states that you should not issue any config
+	 * requests until 100ms after asserting reset, so we enforce that here
+	 */
+	msleep(100);
+}
+
+static void st_pcie_hw_setup(struct pcie_port *pp)
+{
+	struct st_pcie *pcie = to_st_pcie(pp);
+
+	dw_pcie_setup_rc(pp);
+
+	/* Set up the config window to the top of the PCI address space */
+	writel_relaxed(pcie->config_window_start,
+		       pp->dbi_base + CFG_BASE_ADDRESS);
+
+	/*
+	 * Open up memory to the PCI controller. We could do slightly
+	 * better than this and exclude the kernel text segment and bss etc.
+	 * They are base/limit registers so can be of arbitrary alignment
+	 * presumably
+	 */
+	writel_relaxed(pcie->lmi->start, pp->dbi_base + IN0_MEM_ADDR_START);
+	writel_relaxed(pcie->lmi->end, pp->dbi_base + IN0_MEM_ADDR_LIMIT);
+
+	/* Disable the 2nd region */
+	writel_relaxed(~0, pp->dbi_base + IN1_MEM_ADDR_START);
+	writel_relaxed(0, pp->dbi_base + IN1_MEM_ADDR_LIMIT);
+
+	writel_relaxed(RC_PASS_ADDR_RANGE, pp->dbi_base + TRANSLATION_CONTROL);
+
+	/* Now assert the board level reset to the other PCIe device */
+	st_pcie_board_reset(pp);
+}
+
+static irqreturn_t st_pcie_msi_irq_handler(int irq, void *arg)
+{
+	struct pcie_port *pp = arg;
+
+	return dw_handle_msi_irq(pp);
+}
+
+static int st_pcie_init(struct pcie_port *pp)
+{
+	struct st_pcie *pcie = to_st_pcie(pp);
+	int ret;
+
+	ret = reset_control_deassert(pcie->pwr);
+	if (ret) {
+		dev_err(pp->dev, "unable to bring out of powerdown\n");
+		return ret;
+	}
+
+	ret = reset_control_deassert(pcie->rst);
+	if (ret) {
+		dev_err(pp->dev, "unable to bring out of softreset\n");
+		return ret;
+	}
+
+	/* Set device type : Root Complex */
+	ret = regmap_write(pcie->regmap, pcie->syscfg0, PCIE_DEVICE_TYPE);
+	if (ret < 0) {
+		dev_err(pp->dev, "unable to set device type\n");
+		return ret;
+	}
+
+	usleep_range(1000, 2000);
+	return ret;
+}
+
+static int st_pcie_enable_ltssm(struct pcie_port *pp)
+{
+	struct st_pcie *pcie = to_st_pcie(pp);
+
+	return regmap_update_bits(pcie->regmap, pcie->syscfg1,
+				  PCIE_APP_LTSSM_ENABLE, PCIE_APP_LTSSM_ENABLE);
+}
+
+static int st_pcie_disable_ltssm(struct pcie_port *pp)
+{
+	struct st_pcie *pcie = to_st_pcie(pp);
+
+	return regmap_update_bits(pcie->regmap, pcie->syscfg1,
+				  PCIE_APP_LTSSM_ENABLE, 0);
+}
+
+static void st_pcie_host_init(struct pcie_port *pp)
+{
+	struct st_pcie *pcie = to_st_pcie(pp);
+	int err;
+
+	/*
+	 * We have to initialise the PCIe cell on some hardware before we can
+	 * talk to the phy
+	 */
+	err = st_pcie_init(pp);
+	if (err)
+		return;
+
+	err = st_pcie_disable_ltssm(pp);
+	if (err) {
+		dev_err(pp->dev, "disable ltssm failed, %d\n", err);
+		return;
+	}
+
+	/* Now init the associated miphy */
+	err = phy_init(pcie->phy);
+	if (err < 0) {
+		dev_err(pp->dev, "Cannot init PHY: %d\n", err);
+		return;
+	}
+
+	/* Now do all the register poking */
+	st_pcie_hw_setup(pp);
+
+	/* Re-enable the link */
+	err = st_pcie_enable_ltssm(pp);
+	if (err)
+		dev_err(pp->dev, "enable ltssm failed, %d\n", err);
+
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		dw_pcie_msi_init(pp);
+}
+
+static struct pcie_host_ops st_pcie_host_ops = {
+	.rd_other_conf = st_pcie_rd_other_conf,
+	.wr_other_conf = st_pcie_wr_other_conf,
+	.link_up = st_pcie_link_up,
+	.host_init = st_pcie_host_init,
+};
+
+static const struct of_device_id st_pcie_of_match[] = {
+	{ .compatible = "st,pcie", },
+	{ },
+};
+
+static int __init st_pcie_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct st_pcie *pcie;
+	struct device_node *np = pdev->dev.of_node;
+	struct pcie_port *pp;
+	int ret;
+
+	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	memset(pcie, 0, sizeof(*pcie));
+
+	pp = &pcie->pp;
+	pp->dev = &pdev->dev;
+
+	/* mem regions */
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+	pp->dbi_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pp->dbi_base))
+		return PTR_ERR(pp->dbi_base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
+	if (!res)
+		return -ENXIO;
+
+	/* Check that this has sensible values */
+	if ((resource_size(res) != CFG_REGION_SIZE) ||
+	    (res->start & (CFG_REGION_SIZE - 1))) {
+		dev_err(&pdev->dev, "Invalid config space properties\n");
+		return -EINVAL;
+	}
+	pcie->config_window_start = res->start;
+
+	pp->va_cfg0_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pp->va_cfg0_base))
+		return PTR_ERR(pp->va_cfg0_base);
+	pp->va_cfg1_base = pp->va_cfg0_base + CFG_SPACE1_OFFSET;
+
+	pcie->lmi = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						 "mem-window");
+	if (!pcie->lmi)
+		return -ENXIO;
+
+	/* regmap registers for PCIe IP configuration */
+	pcie->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+	if (IS_ERR(pcie->regmap)) {
+		dev_err(&pdev->dev, "No syscfg phandle specified\n");
+		return PTR_ERR(pcie->regmap);
+	}
+
+	ret = of_property_read_u32_index(np, "st,syscfg", SYSCFG0_REG,
+					 &pcie->syscfg0);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get syscfg0 offset (%d)\n", ret);
+		return ret;
+	}
+
+	ret = of_property_read_u32_index(np, "st,syscfg", SYSCFG1_REG,
+					 &pcie->syscfg1);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get syscfg1 offset (%d)\n", ret);
+		return ret;
+	}
+
+	/* powerdown / resets */
+	pcie->pwr = devm_reset_control_get(&pdev->dev, "powerdown");
+	if (IS_ERR(pcie->pwr)) {
+		dev_err(&pdev->dev, "powerdown reset control not defined\n");
+		return PTR_ERR(pcie->pwr);
+	}
+
+	pcie->rst = devm_reset_control_get(&pdev->dev, "softreset");
+	if (IS_ERR(pcie->rst)) {
+		dev_err(&pdev->dev, "Soft reset control not defined\n");
+		return PTR_ERR(pcie->pwr);
+	}
+
+	/* phy */
+	pcie->phy = devm_phy_get(&pdev->dev, "pcie");
+	if (IS_ERR(pcie->phy)) {
+		dev_err(&pdev->dev, "no PHY configured\n");
+		return PTR_ERR(pcie->phy);
+	}
+
+	/* Claim the GPIO for PRST# if available */
+	pcie->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
+	if (!gpio_is_valid(pcie->reset_gpio))
+		dev_dbg(&pdev->dev, "No reset-gpio configured\n");
+	else {
+		ret = devm_gpio_request(&pdev->dev,
+					pcie->reset_gpio,
+					"PCIe reset");
+		if (ret) {
+			dev_err(&pdev->dev, "Cannot request reset-gpio %d\n",
+				pcie->reset_gpio);
+			return ret;
+		}
+	}
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		pp->msi_irq = platform_get_irq_byname(pdev, "msi");
+		if (pp->msi_irq <= 0) {
+			dev_err(&pdev->dev, "failed to get MSI irq\n");
+			return -ENODEV;
+		}
+
+		ret = devm_request_irq(&pdev->dev, pp->msi_irq,
+				       st_pcie_msi_irq_handler,
+				       IRQF_SHARED, "st-pcie-msi", pp);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to request MSI irq\n");
+			return -ENODEV;
+		}
+	}
+
+	if (IS_ENABLED(CONFIG_ARM)) {
+		/*
+		 * We have to hook the abort handler so that we can intercept
+		 * bus errors when doing config read/write that return UR,
+		 * which is flagged up as a bus error
+		 */
+		hook_fault_code(16+6, st_pcie_abort_handler, SIGBUS, 0,
+				"imprecise external abort");
+	}
+
+	pp->root_bus_nr = -1;
+	pp->ops = &st_pcie_host_ops;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to initialize host\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, pcie);
+
+	dev_info(&pdev->dev, "Initialized\n");
+	return 0;
+}
+
+MODULE_DEVICE_TABLE(of, st_pcie_of_match);
+
+static struct platform_driver st_pcie_driver = {
+	.driver = {
+		.name = "st-pcie",
+		.of_match_table = st_pcie_of_match,
+	},
+};
+
+/* ST PCIe driver does not allow module unload */
+static int __init pcie_init(void)
+{
+	return platform_driver_probe(&st_pcie_driver, st_pcie_probe);
+}
+module_init(pcie_init);
+
+MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
+MODULE_DESCRIPTION("PCI express Driver for ST SoCs");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

[PATCH v4 4/4] MAINTAINERS: Add pci-st.c to ARCH/STI architecture

[Gabriel Fernandez]

This patch adds the pci-st.c pci driver found on STMicroelectronics
SoC's into the STI arch section of the maintainers file.

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 8133cef..af5034f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1506,6 +1506,7 @@ F:	drivers/clocksource/arm_global_timer.c
 F:	drivers/i2c/busses/i2c-st.c
 F:	drivers/media/rc/st_rc.c
 F:	drivers/mmc/host/sdhci-st.c
+F:	drivers/pci/host/pci-st.c
 F:	drivers/phy/phy-miphy28lp.c
 F:	drivers/phy/phy-miphy365x.c
 F:	drivers/phy/phy-stih407-usb.c
-- 
1.9.1

Re: [PATCH v4 3/4] PCI: st: Provide support for the sti PCIe controller

[Pratyush Anand]

Hi Gabriel,

Looks good to me.

On Thu, Aug 27, 2015 at 6:04 PM, Gabriel Fernandez
<gabriel.fernandez@linaro.org> wrote:
> sti pcie is built around a Synopsis Designware PCIe IP.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
> Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>


> +static int st_pcie_link_up(struct pcie_port *pp)
> +{
> +       u32 status;
> +       int link_up;

nit: why not bool

> +       int count = 0;

[...]

> +static void st_pcie_board_reset(struct pcie_port *pp)
> +{
> +       struct st_pcie *pcie = to_st_pcie(pp);
> +
> +       if (!gpio_is_valid(pcie->reset_gpio))
> +               return;
> +
> +       if (gpio_direction_output(pcie->reset_gpio, 0)) {
> +               dev_err(pp->dev, "Cannot set PERST# (gpio %u) to output\n",
> +                       pcie->reset_gpio);
> +               return;
> +       }
> +
> +       /* From PCIe spec */
> +       msleep(2);
> +       gpio_direction_output(pcie->reset_gpio, 1);
> +
> +       /*
> +        * PCIe specification states that you should not issue any config
> +        * requests until 100ms after asserting reset, so we enforce that here
> +        */
> +       msleep(100);

IIRC, specification says to wait after link training completes. So
shouldn't it be after st_pcie_enable_ltssm. Moreover, I wonder why
others do not need it.

Reviewed-by: Pratyush Anand <pratyush.anand@gmail.com>

Re: [PATCH v4 2/4] PCI: st: Add Device Tree bindings for sti pcie

[Rob Herring]

On Thu, Aug 27, 2015 at 7:34 AM, Gabriel Fernandez
<gabriel.fernandez-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> sti pcie is built around a Synopsis Designware PCIe IP.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier-qxv4g6HH51o@public.gmane.org>
> Signed-off-by: Gabriel Fernandez <gabriel.fernandez-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> ---
>  Documentation/devicetree/bindings/pci/st-pcie.txt | 53 +++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/st-pcie.txt
>
> diff --git a/Documentation/devicetree/bindings/pci/st-pcie.txt b/Documentation/devicetree/bindings/pci/st-pcie.txt
> new file mode 100644
> index 0000000..25fcab3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/st-pcie.txt
> @@ -0,0 +1,53 @@
> +STMicroelectronics STi PCIe controller
> +
> +This PCIe host controller is based on the Synopsis Designware PCIe IP
> +and thus inherits all the common properties defined in designware-pcie.txt.
> +
> +Required properties:
> + - compatible: "st,stih407-pcie"

What about "snps,dw-pcie" as well?

> + - reg: base address and length of the pcie controller, mem-window address
> +   and length available to the controller.

What is mem-window? Seems rather large and perhaps should be under ranges.

> + - interrupts: A list of interrupt outputs of the controller. Must contain an
> +   entry for each entry in the interrupt-names property.

Define how many interrupts.

> + - interrupt-names: Should be "msi". STi interrupt that is asserted when an
> +   MSI is received.

Kind of pointless with a single interrupt.

> + - st,syscfg : should be a phandle of the syscfg node. Also contains syscfg
> +   offset for IP configuration.
> + - resets, reset-names: the power-down and soft-reset lines of PCIe IP.
> +   Associated names must be "powerdown" and "softreset".
> + - phys, phy-names: the phandle for the PHY device.
> +   Associated name must be "pcie"

What does this mean?

> +
> +Optional properties:
> + - reset-gpio: a GPIO spec to define which pin is connected to the bus reset.
> +
> +Example:
> +
> +pcie0: pcie@9b00000 {
> +       compatible = "st,pcie", "snps,dw-pcie";
> +       device_type = "pci";
> +       reg = <0x09b00000 0x4000>,      /* dbi cntrl registers */
> +             <0x2fff0000 0x00010000>,  /* configuration space */
> +             <0x40000000 0x80000000>;  /* lmi mem window */
> +       reg-names = "dbi", "config", "mem-window";
> +       st,syscfg = <&syscfg_core 0xd8 0xe0>;
> +       #address-cells = <3>;
> +       #size-cells = <2>;
> +       ranges = <0x82000000 0 0x20000000 0x20000000 0 0x0FFF0000>; /* non-prefetchable memory */

No i/o support?

> +       num-lanes = <1>;
> +       interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
> +       interrupt-names = "msi";
> +       #interrupt-cells = <1>;
> +       interrupt-map-mask = <0 0 0 7>;
> +       interrupt-map = <0 0 0 1 &intc GIC_SPI 160 IRQ_TYPE_LEVEL_HIGH>, /* INT A */
> +                       <0 0 0 2 &intc GIC_SPI 161 IRQ_TYPE_LEVEL_HIGH>, /* INT B */
> +                       <0 0 0 3 &intc GIC_SPI 162 IRQ_TYPE_LEVEL_HIGH>, /* INT C */
> +                       <0 0 0 4 &intc GIC_SPI 163 IRQ_TYPE_LEVEL_HIGH>; /* INT D */
> +
> +       resets = <&powerdown STIH407_PCIE0_POWERDOWN>,
> +                <&softreset STIH407_PCIE0_SOFTRESET>;
> +       reset-names = "powerdown",
> +                     "softreset";
> +       phys = <&phy_port0 PHY_TYPE_PCIE>;
> +       phy-names = "pcie";
> +};
> --
> 1.9.1
>
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Re: [PATCH v4 0/4] PCI: st: provide support for dw pcie

[Bjorn Helgaas]

Hi Gabriel,

On Thu, Aug 27, 2015 at 02:34:13PM +0200, Gabriel Fernandez wrote:
> 
> This patchset is based on v4.2-rc1 and is based on 
> [PATCH v8 0/6] PCI: hisi: Add PCIe host support for HiSilicon SoC Hip05
> patchset from Zhou Wang.
> 
> Changes in v4:
>  - Remove pci: designware: remove my pci_common_init_dev() patch and
> 	use [PATCH v8 3/6] PCI: designware: Add ARM64 support instead.
> 	This patch is a good solution for me to disable IO support.
>  - add __init to st_pcie_probe() and use module_init() instead
> 	device_initcall() to prevent the probe function from being
> 	deferred and to prevent module unloading.
> 
> Changes in v3:
>  - Remove power management functions (was not fully tested)
>  - Remove configuration space range from dt binding
>  - Remove pci_common_init_dev() call in pcie-designware.c to avoid 
>    default IO space declaration. 
> 
> Changes in v2:
>  - comestic corrections in device tree binding
>  - add pci-st.c into MAINTAINERS
>  - remove st_pcie_ops structure to avoid another level of indirection
>  - remove nasty busy-loop
>  - remove useless test using virt_to_phys()
>  - move disable io support into dw-pcie driver
> 
> I don't change the st_pcie_abort_handler() function because abort handling
> is masked during boot.
> 
> 
> This patch-set introduces a STMicroelectronics PCIe controller.
> It's based on designware PCIe driver.
> 
> Gabriel Fernandez (4):
>   ARM: STi: Kconfig update for PCIe support
>   PCI: st: Add Device Tree bindings for sti pcie
>   PCI: st: Provide support for the sti PCIe controller
>   MAINTAINERS: Add pci-st.c to ARCH/STI architecture

Rob had some questions, so I'm waiting for an update that responds to
those.  When you post that, can you also squash the last two patches
together?

Thanks,
  Bjorn

>  Documentation/devicetree/bindings/pci/st-pcie.txt |  53 ++
>  MAINTAINERS                                       |   1 +
>  arch/arm/mach-sti/Kconfig                         |   2 +
>  drivers/pci/host/Kconfig                          |   9 +
>  drivers/pci/host/Makefile                         |   1 +
>  drivers/pci/host/pci-st.c                         | 583 ++++++++++++++++++++++
>  6 files changed, 649 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/st-pcie.txt
>  create mode 100644 drivers/pci/host/pci-st.c
> 
> -- 
> 1.9.1
> 

Re: [PATCH v4 0/4] PCI: st: provide support for dw pcie

[Gabriel Fernandez]

No problem

Thanks

Gabriel

On 17 September 2015 at 16:59, Bjorn Helgaas <bhelgaas@google.com> wrote:
> Hi Gabriel,
>
> On Thu, Aug 27, 2015 at 02:34:13PM +0200, Gabriel Fernandez wrote:
>>
>> This patchset is based on v4.2-rc1 and is based on
>> [PATCH v8 0/6] PCI: hisi: Add PCIe host support for HiSilicon SoC Hip05
>> patchset from Zhou Wang.
>>
>> Changes in v4:
>>  - Remove pci: designware: remove my pci_common_init_dev() patch and
>>       use [PATCH v8 3/6] PCI: designware: Add ARM64 support instead.
>>       This patch is a good solution for me to disable IO support.
>>  - add __init to st_pcie_probe() and use module_init() instead
>>       device_initcall() to prevent the probe function from being
>>       deferred and to prevent module unloading.
>>
>> Changes in v3:
>>  - Remove power management functions (was not fully tested)
>>  - Remove configuration space range from dt binding
>>  - Remove pci_common_init_dev() call in pcie-designware.c to avoid
>>    default IO space declaration.
>>
>> Changes in v2:
>>  - comestic corrections in device tree binding
>>  - add pci-st.c into MAINTAINERS
>>  - remove st_pcie_ops structure to avoid another level of indirection
>>  - remove nasty busy-loop
>>  - remove useless test using virt_to_phys()
>>  - move disable io support into dw-pcie driver
>>
>> I don't change the st_pcie_abort_handler() function because abort handling
>> is masked during boot.
>>
>>
>> This patch-set introduces a STMicroelectronics PCIe controller.
>> It's based on designware PCIe driver.
>>
>> Gabriel Fernandez (4):
>>   ARM: STi: Kconfig update for PCIe support
>>   PCI: st: Add Device Tree bindings for sti pcie
>>   PCI: st: Provide support for the sti PCIe controller
>>   MAINTAINERS: Add pci-st.c to ARCH/STI architecture
>
> Rob had some questions, so I'm waiting for an update that responds to
> those.  When you post that, can you also squash the last two patches
> together?
>
> Thanks,
>   Bjorn
>
>>  Documentation/devicetree/bindings/pci/st-pcie.txt |  53 ++
>>  MAINTAINERS                                       |   1 +
>>  arch/arm/mach-sti/Kconfig                         |   2 +
>>  drivers/pci/host/Kconfig                          |   9 +
>>  drivers/pci/host/Makefile                         |   1 +
>>  drivers/pci/host/pci-st.c                         | 583 ++++++++++++++++++++++
>>  6 files changed, 649 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/pci/st-pcie.txt
>>  create mode 100644 drivers/pci/host/pci-st.c
>>
>> --
>> 1.9.1
>>

Re: [PATCH v4 2/4] PCI: st: Add Device Tree bindings for sti pcie

[Gabriel Fernandez]

Hi Rob,

Thanks for the review.

Best regards

Gabriel

On 28 August 2015 at 02:06, Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On Thu, Aug 27, 2015 at 7:34 AM, Gabriel Fernandez
> <gabriel.fernandez-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
>> sti pcie is built around a Synopsis Designware PCIe IP.
>>
>> Signed-off-by: Fabrice Gasnier <fabrice.gasnier-qxv4g6HH51o@public.gmane.org>
>> Signed-off-by: Gabriel Fernandez <gabriel.fernandez-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>> ---
>>  Documentation/devicetree/bindings/pci/st-pcie.txt | 53 +++++++++++++++++++++++
>>  1 file changed, 53 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/pci/st-pcie.txt
>>
>> diff --git a/Documentation/devicetree/bindings/pci/st-pcie.txt b/Documentation/devicetree/bindings/pci/st-pcie.txt
>> new file mode 100644
>> index 0000000..25fcab3
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pci/st-pcie.txt
>> @@ -0,0 +1,53 @@
>> +STMicroelectronics STi PCIe controller
>> +
>> +This PCIe host controller is based on the Synopsis Designware PCIe IP
>> +and thus inherits all the common properties defined in designware-pcie.txt.
>> +
>> +Required properties:
>> + - compatible: "st,stih407-pcie"
>
> What about "snps,dw-pcie" as well?
>
You are right.

>> + - reg: base address and length of the pcie controller, mem-window address
>> +   and length available to the controller.
>
> What is mem-window? Seems rather large and perhaps should be under ranges.
>
No the purpose is to specify the physical memory available to the controller.
reg property is more appropriate.

>> + - interrupts: A list of interrupt outputs of the controller. Must contain an
>> +   entry for each entry in the interrupt-names property.
>
> Define how many interrupts.
>
ok i will fix it.

>> + - interrupt-names: Should be "msi". STi interrupt that is asserted when an
>> +   MSI is received.
>
> Kind of pointless with a single interrupt.
>
ok

>> + - st,syscfg : should be a phandle of the syscfg node. Also contains syscfg
>> +   offset for IP configuration.
>> + - resets, reset-names: the power-down and soft-reset lines of PCIe IP.
>> +   Associated names must be "powerdown" and "softreset".
>> + - phys, phy-names: the phandle for the PHY device.
>> +   Associated name must be "pcie"
>
> What does this mean?
>
i will reformulate this paragraph.

>> +
>> +Optional properties:
>> + - reset-gpio: a GPIO spec to define which pin is connected to the bus reset.
>> +
>> +Example:
>> +
>> +pcie0: pcie@9b00000 {
>> +       compatible = "st,pcie", "snps,dw-pcie";
>> +       device_type = "pci";
>> +       reg = <0x09b00000 0x4000>,      /* dbi cntrl registers */
>> +             <0x2fff0000 0x00010000>,  /* configuration space */
>> +             <0x40000000 0x80000000>;  /* lmi mem window */
>> +       reg-names = "dbi", "config", "mem-window";
>> +       st,syscfg = <&syscfg_core 0xd8 0xe0>;
>> +       #address-cells = <3>;
>> +       #size-cells = <2>;
>> +       ranges = <0x82000000 0 0x20000000 0x20000000 0 0x0FFF0000>; /* non-prefetchable memory */
>
> No i/o support?
>
Exactly there is no i/o support.

>> +       num-lanes = <1>;
>> +       interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
>> +       interrupt-names = "msi";
>> +       #interrupt-cells = <1>;
>> +       interrupt-map-mask = <0 0 0 7>;
>> +       interrupt-map = <0 0 0 1 &intc GIC_SPI 160 IRQ_TYPE_LEVEL_HIGH>, /* INT A */
>> +                       <0 0 0 2 &intc GIC_SPI 161 IRQ_TYPE_LEVEL_HIGH>, /* INT B */
>> +                       <0 0 0 3 &intc GIC_SPI 162 IRQ_TYPE_LEVEL_HIGH>, /* INT C */
>> +                       <0 0 0 4 &intc GIC_SPI 163 IRQ_TYPE_LEVEL_HIGH>; /* INT D */
>> +
>> +       resets = <&powerdown STIH407_PCIE0_POWERDOWN>,
>> +                <&softreset STIH407_PCIE0_SOFTRESET>;
>> +       reset-names = "powerdown",
>> +                     "softreset";
>> +       phys = <&phy_port0 PHY_TYPE_PCIE>;
>> +       phy-names = "pcie";
>> +};
>> --
>> 1.9.1
>>
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Re: [PATCH v4 3/4] PCI: st: Provide support for the sti PCIe controller

[Gabriel Fernandez]

Hi Pratyush,

Thanks for the review.

Best regards

Gabriel

On 27 August 2015 at 19:31, Pratyush Anand <pratyush.anand-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Hi Gabriel,
>
> Looks good to me.
>
> On Thu, Aug 27, 2015 at 6:04 PM, Gabriel Fernandez
> <gabriel.fernandez-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
>> sti pcie is built around a Synopsis Designware PCIe IP.
>>
>> Signed-off-by: Fabrice Gasnier <fabrice.gasnier-qxv4g6HH51o@public.gmane.org>
>> Signed-off-by: Gabriel Fernandez <gabriel.fernandez-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>
>
>> +static int st_pcie_link_up(struct pcie_port *pp)
>> +{
>> +       u32 status;
>> +       int link_up;
>
> nit: why not bool

i prefer to keep it as 'int' because the prototype of link_up callback
is an 'int'.

>
>> +       int count = 0;
>
> [...]
>
>> +static void st_pcie_board_reset(struct pcie_port *pp)
>> +{
>> +       struct st_pcie *pcie = to_st_pcie(pp);
>> +
>> +       if (!gpio_is_valid(pcie->reset_gpio))
>> +               return;
>> +
>> +       if (gpio_direction_output(pcie->reset_gpio, 0)) {
>> +               dev_err(pp->dev, "Cannot set PERST# (gpio %u) to output\n",
>> +                       pcie->reset_gpio);
>> +               return;
>> +       }
>> +
>> +       /* From PCIe spec */
>> +       msleep(2);
>> +       gpio_direction_output(pcie->reset_gpio, 1);
>> +
>> +       /*
>> +        * PCIe specification states that you should not issue any config
>> +        * requests until 100ms after asserting reset, so we enforce that here
>> +        */
>> +       msleep(100);
>
> IIRC, specification says to wait after link training completes. So
> shouldn't it be after st_pcie_enable_ltssm. Moreover, I wonder why
> others do not need it.
>
Ok i will fix it.

> Reviewed-by: Pratyush Anand <pratyush.anand-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
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