[d-kernel] [PATCH 27/31] PCI: pcie-baikal: driver for Baikal-M with new firmware
Alexey Sheplyakov
asheplyakov на basealt.ru
Пн Окт 3 17:02:23 MSK 2022
This driver works with firmware from SDK-M 5.5. dw-pcie should be
used with older firmware (such as SDK-M 5.3)
Note: this driver uses `baikal,bm1000-pcie` as a compatible string.
Hence the kernel with this driver can run on Baikal-M boards with
older firmware (and use dw-pcie driver instead of this one).
Known to work with Delta Computers' Rhodeola board, firmware
5.5_rdl_220425_1_debug.cap
Co-developed-by: Pavel Parkhomenko <pavel.parkhomenko на baikalelectronics.ru>
Co-developed-by: Mikhail Ivanov <michail.ivanov на baikalelectronics.ru>
Co-developed-by: Aleksandr Efimov <alexander.efimov на baikalelectronics.ru>
Signed-off-by: Alexey Sheplyakov <asheplyakov на basealt.ru>
X-DONTUPSTREAM
X-feature-Baikal-M
---
drivers/pci/controller/dwc/Kconfig | 12 +
drivers/pci/controller/dwc/Makefile | 1 +
drivers/pci/controller/dwc/pcie-baikal.c | 740 +++++++++++++++++++++++
3 files changed, 753 insertions(+)
create mode 100644 drivers/pci/controller/dwc/pcie-baikal.c
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 62ce3abf0f19..b6a1245122d9 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -272,6 +272,18 @@ config PCIE_KEEMBAY_EP
The PCIe controller is based on DesignWare Hardware and uses
DesignWare core functions.
+config PCI_BAIKAL
+ bool "Baikal SoC PCIe controller"
+ depends on ARCH_BAIKAL
+ depends on OF && HAS_IOMEM
+ select PCIE_DW_HOST
+ select PCI_MSI_IRQ_DOMAIN
+ select PCI_QUIRKS if ACPI
+ help
+ Enables support for the PCIe controller in the Baikal SoC. There are
+ three instances of PCIe controller in Baikal-M. Two of the controllers
+ support PCIe 3.0 x4 and the remaining one supports PCIe 3.0 x8.
+
config PCIE_KIRIN
depends on OF && (ARM64 || COMPILE_TEST)
tristate "HiSilicon Kirin series SoCs PCIe controllers"
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 8ba7b67f5e50..db5f526a60f0 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_PCIE_TEGRA194) += pcie-tegra194.o
obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o
+obj-$(CONFIG_PCI_BAIKAL) += pcie-baikal.o
# The following drivers are for devices that use the generic ACPI
# pci_root.c driver but don't support standard ECAM config access.
diff --git a/drivers/pci/controller/dwc/pcie-baikal.c b/drivers/pci/controller/dwc/pcie-baikal.c
new file mode 100644
index 000000000000..340a6b12cd4e
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-baikal.c
@@ -0,0 +1,740 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe RC driver for Baikal-M SoC
+ *
+ * Copyright (C) 2019-2021 Baikal Electronics, JSC
+ * Authors: Pavel Parkhomenko <pavel.parkhomenko на baikalelectronics.ru>
+ * Mikhail Ivanov <michail.ivanov на baikalelectronics.ru>
+ * Aleksandr Efimov <alexander.efimov на baikalelectronics.ru>
+ */
+
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/arm-gic-v3.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/pci.h>
+#include <linux/pci-ecam.h>
+#include <linux/phy/phy.h>
+#include <linux/regmap.h>
+#include <linux/resource.h>
+
+#include "pcie-designware.h"
+
+struct baikal_pcie_rc {
+ struct dw_pcie *pcie;
+ unsigned num;
+ struct regmap *lcru;
+ struct gpio_desc *reset_gpio;
+ bool reset_active_low;
+ char reset_name[32];
+ bool retrained;
+};
+
+#define to_baikal_pcie_rc(x) dev_get_drvdata((x)->dev)
+
+#define PCIE_DEVICE_CONTROL_DEVICE_STATUS_REG 0x78
+#define PCIE_CAP_CORR_ERR_REPORT_EN BIT(0)
+#define PCIE_CAP_NON_FATAL_ERR_REPORT_EN BIT(1)
+#define PCIE_CAP_FATAL_ERR_REPORT_EN BIT(2)
+#define PCIE_CAP_UNSUPPORT_REQ_REP_EN BIT(3)
+
+#define PCIE_LINK_CAPABILITIES_REG 0x7c
+
+#define PCIE_LINK_CONTROL_LINK_STATUS_REG 0x80
+#define PCIE_CAP_LINK_SPEED_MASK 0xf0000
+#define PCIE_CAP_LINK_SPEED_SHIFT 16
+#define PCIE_CAP_NEGO_LINK_WIDTH_MASK 0x3f00000
+#define PCIE_CAP_NEGO_LINK_WIDTH_SHIFT 20
+#define PCIE_CAP_LINK_TRAINING BIT(27)
+
+#define PCIE_ROOT_CONTROL_ROOT_CAPABILITIES_REG 0x8c
+#define PCIE_CAP_SYS_ERR_ON_CORR_ERR_EN BIT(0)
+#define PCIE_CAP_SYS_ERR_ON_NON_FATAL_ERR_EN BIT(1)
+#define PCIE_CAP_SYS_ERR_ON_FATAL_ERR_EN BIT(2)
+#define PCIE_CAP_PME_INT_EN BIT(3)
+
+#define PCIE_LINK_CONTROL2_LINK_STATUS2_REG 0xa0
+#define PCIE_CAP_TARGET_LINK_SPEED_MASK 0xf
+
+#define PCIE_UNCORR_ERR_STATUS_REG 0x104
+#define PCIE_CORR_ERR_STATUS_REG 0x110
+
+#define PCIE_ROOT_ERR_CMD_REG 0x12c
+#define PCIE_CORR_ERR_REPORTING_EN BIT(0)
+#define PCIE_NON_FATAL_ERR_REPORTING_EN BIT(1)
+#define PCIE_FATAL_ERR_REPORTING_EN BIT(2)
+
+#define PCIE_ROOT_ERR_STATUS_REG 0x130
+
+#define PCIE_GEN2_CTRL_REG 0x80c
+#define PCIE_DIRECT_SPEED_CHANGE BIT(17)
+
+#define PCIE_IATU_VIEWPORT_REG 0x900
+#define PCIE_IATU_REGION_OUTBOUND 0
+#define PCIE_IATU_REGION_CTRL_2_REG 0x908
+#define PCIE_IATU_REGION_CTRL_2_REG_SHIFT_MODE BIT(28)
+
+#define BAIKAL_LCRU_PCIE_RESET_BASE 0x50000
+#define BAIKAL_LCRU_PCIE_RESET(x) ((x * 0x20) + BAIKAL_LCRU_PCIE_RESET_BASE)
+#define BAIKAL_PCIE_PHY_RST BIT(0)
+#define BAIKAL_PCIE_PIPE_RST BIT(4) /* x4 controllers only */
+#define BAIKAL_PCIE_PIPE0_RST BIT(4) /* x8 controller only */
+#define BAIKAL_PCIE_PIPE1_RST BIT(5) /* x8 controller only */
+#define BAIKAL_PCIE_CORE_RST BIT(8)
+#define BAIKAL_PCIE_PWR_RST BIT(9)
+#define BAIKAL_PCIE_STICKY_RST BIT(10)
+#define BAIKAL_PCIE_NONSTICKY_RST BIT(11)
+#define BAIKAL_PCIE_HOT_RST BIT(12)
+#define BAIKAL_PCIE_ADB_PWRDWN BIT(13)
+
+#define BAIKAL_LCRU_PCIE_STATUS_BASE 0x50004
+#define BAIKAL_LCRU_PCIE_STATUS(x) ((x * 0x20) + BAIKAL_LCRU_PCIE_STATUS_BASE)
+#define BAIKAL_PCIE_LTSSM_MASK 0x3f
+#define BAIKAL_PCIE_LTSSM_STATE_L0 0x11
+
+#define BAIKAL_LCRU_PCIE_GEN_CTL_BASE 0x50008
+#define BAIKAL_LCRU_PCIE_GEN_CTL(x) ((x * 0x20) + BAIKAL_LCRU_PCIE_GEN_CTL_BASE)
+#define BAIKAL_PCIE_LTSSM_ENABLE BIT(1)
+#define BAIKAL_PCIE_DBI2_MODE BIT(2)
+#define BAIKAL_PCIE_PHY_MGMT_ENABLE BIT(3)
+
+#define BAIKAL_LCRU_PCIE_MSI_TRANS_CTL2 0x500f8
+#define BAIKAL_LCRU_PCIE_MSI_TRANS_CTL2_PCIE_MSI_TRANS_EN(x) BIT(9 + (x))
+#define BAIKAL_LCRU_PCIE_MSI_TRANS_CTL2_PCIE_RCNUM(x) ((x) << (2 * (x)))
+#define BAIKAL_LCRU_PCIE_MSI_TRANS_CTL2_PCIE_RCNUM_MASK(x) ((3) << (2 * (x)))
+
+static int baikal_pcie_link_up(struct dw_pcie *pcie)
+{
+ struct baikal_pcie_rc *rc = to_baikal_pcie_rc(pcie);
+ u32 reg;
+
+ regmap_read(rc->lcru, BAIKAL_LCRU_PCIE_GEN_CTL(rc->num), ®);
+ if (!(reg & BAIKAL_PCIE_LTSSM_ENABLE)) {
+ return 0;
+ }
+
+ regmap_read(rc->lcru, BAIKAL_LCRU_PCIE_STATUS(rc->num), ®);
+ return (reg & BAIKAL_PCIE_LTSSM_MASK) == BAIKAL_PCIE_LTSSM_STATE_L0;
+}
+
+static int baikal_pcie_host_init(struct dw_pcie_rp *pp)
+{
+ struct dw_pcie *pcie = to_dw_pcie_from_pp(pp);
+ struct baikal_pcie_rc *rc = to_baikal_pcie_rc(pcie);
+ struct device *dev = pcie->dev;
+ int err;
+ int linkup;
+ unsigned idx;
+ u32 reg;
+
+ /* Disable access to PHY registers and DBI2 mode */
+ regmap_read(rc->lcru, BAIKAL_LCRU_PCIE_GEN_CTL(rc->num), ®);
+ reg &= ~(BAIKAL_PCIE_PHY_MGMT_ENABLE |
+ BAIKAL_PCIE_DBI2_MODE);
+ regmap_write(rc->lcru, BAIKAL_LCRU_PCIE_GEN_CTL(rc->num), reg);
+
+ rc->retrained = false;
+ linkup = baikal_pcie_link_up(pcie);
+
+ /* If link is not established yet, reset the RC */
+ if (!linkup) {
+ /* Disable link training */
+ regmap_read(rc->lcru, BAIKAL_LCRU_PCIE_GEN_CTL(rc->num), ®);
+ reg &= ~BAIKAL_PCIE_LTSSM_ENABLE;
+ regmap_write(rc->lcru, BAIKAL_LCRU_PCIE_GEN_CTL(rc->num), reg);
+
+ /* Assert PERST pin */
+ if (rc->reset_gpio != NULL) {
+ unsigned long gpio_flags;
+
+ if (rc->reset_active_low) {
+ gpio_flags = GPIOF_ACTIVE_LOW |
+ GPIOF_OUT_INIT_LOW;
+ } else {
+ gpio_flags = GPIOF_OUT_INIT_HIGH;
+ }
+
+ err = devm_gpio_request_one(dev,
+ desc_to_gpio(rc->reset_gpio),
+ gpio_flags, rc->reset_name);
+ if (err) {
+ dev_err(dev, "request GPIO failed (%d)\n", err);
+ return err;
+ }
+ }
+
+ /* Reset the RC */
+ regmap_read(rc->lcru, BAIKAL_LCRU_PCIE_RESET(rc->num), ®);
+ reg |= BAIKAL_PCIE_NONSTICKY_RST |
+ BAIKAL_PCIE_STICKY_RST |
+ BAIKAL_PCIE_PWR_RST |
+ BAIKAL_PCIE_CORE_RST |
+ BAIKAL_PCIE_PHY_RST;
+
+ /* If the RC is PCIe x8, reset PIPE0 and PIPE1 */
+ if (rc->num == 2) {
+ reg |= BAIKAL_PCIE_PIPE0_RST |
+ BAIKAL_PCIE_PIPE1_RST;
+ } else {
+ reg |= BAIKAL_PCIE_PIPE_RST;
+ }
+
+ regmap_write(rc->lcru, BAIKAL_LCRU_PCIE_RESET(rc->num), reg);
+
+ usleep_range(20000, 30000);
+
+ if (rc->reset_gpio != NULL) {
+ /* Deassert PERST pin */
+ gpiod_set_value_cansleep(rc->reset_gpio, 0);
+ }
+
+ /* Deassert PHY reset */
+ regmap_read(rc->lcru, BAIKAL_LCRU_PCIE_RESET(rc->num), ®);
+ reg &= ~BAIKAL_PCIE_PHY_RST;
+ regmap_write(rc->lcru, BAIKAL_LCRU_PCIE_RESET(rc->num), reg);
+
+ /* Deassert all software controlled resets */
+ regmap_read(rc->lcru, BAIKAL_LCRU_PCIE_RESET(rc->num), ®);
+ reg &= ~(BAIKAL_PCIE_ADB_PWRDWN |
+ BAIKAL_PCIE_HOT_RST |
+ BAIKAL_PCIE_NONSTICKY_RST |
+ BAIKAL_PCIE_STICKY_RST |
+ BAIKAL_PCIE_PWR_RST |
+ BAIKAL_PCIE_CORE_RST |
+ BAIKAL_PCIE_PHY_RST);
+
+ if (rc->num == 2) {
+ reg &= ~(BAIKAL_PCIE_PIPE0_RST |
+ BAIKAL_PCIE_PIPE1_RST);
+ } else {
+ reg &= ~BAIKAL_PCIE_PIPE_RST;
+ }
+
+ regmap_write(rc->lcru, BAIKAL_LCRU_PCIE_RESET(rc->num), reg);
+ }
+
+ /* Deinitialise all iATU regions */
+ for (idx = 0; idx < pcie->num_ob_windows; ++idx) {
+ dw_pcie_writel_dbi(pcie, PCIE_IATU_VIEWPORT_REG,
+ PCIE_IATU_REGION_OUTBOUND | idx);
+ dw_pcie_writel_dbi(pcie, PCIE_IATU_REGION_CTRL_2_REG, 0);
+ }
+
+ dw_pcie_setup_rc(pp);
+
+ /* Set prog-if 01 [subtractive decode] */
+ dw_pcie_dbi_ro_wr_en(pcie);
+ reg = dw_pcie_readl_dbi(pcie, PCI_CLASS_REVISION);
+ reg = (reg & 0xffff00ff) | (1 << 8);
+ dw_pcie_writel_dbi(pcie, PCI_CLASS_REVISION, reg);
+ dw_pcie_dbi_ro_wr_dis(pcie);
+
+ /* Enable error reporting */
+ reg = dw_pcie_readl_dbi(pcie, PCIE_ROOT_ERR_CMD_REG);
+ reg |= PCIE_CORR_ERR_REPORTING_EN |
+ PCIE_NON_FATAL_ERR_REPORTING_EN |
+ PCIE_FATAL_ERR_REPORTING_EN;
+ dw_pcie_writel_dbi(pcie, PCIE_ROOT_ERR_CMD_REG, reg);
+
+ reg = dw_pcie_readl_dbi(pcie, PCIE_DEVICE_CONTROL_DEVICE_STATUS_REG);
+ reg |= PCIE_CAP_CORR_ERR_REPORT_EN |
+ PCIE_CAP_NON_FATAL_ERR_REPORT_EN |
+ PCIE_CAP_FATAL_ERR_REPORT_EN |
+ PCIE_CAP_UNSUPPORT_REQ_REP_EN;
+ dw_pcie_writel_dbi(pcie, PCIE_DEVICE_CONTROL_DEVICE_STATUS_REG, reg);
+
+ reg = dw_pcie_readl_dbi(pcie, PCIE_ROOT_CONTROL_ROOT_CAPABILITIES_REG);
+ reg |= PCIE_CAP_SYS_ERR_ON_CORR_ERR_EN |
+ PCIE_CAP_SYS_ERR_ON_NON_FATAL_ERR_EN |
+ PCIE_CAP_SYS_ERR_ON_FATAL_ERR_EN |
+ PCIE_CAP_PME_INT_EN;
+ dw_pcie_writel_dbi(pcie, PCIE_ROOT_CONTROL_ROOT_CAPABILITIES_REG, reg);
+
+ if (linkup) {
+ dev_info(dev, "link is already up\n");
+ } else {
+ /* Use Gen1 mode for link establishing */
+ reg = dw_pcie_readl_dbi(pcie,
+ PCIE_LINK_CONTROL2_LINK_STATUS2_REG);
+ reg &= ~PCIE_CAP_TARGET_LINK_SPEED_MASK;
+ reg |= 1;
+ dw_pcie_writel_dbi(pcie,
+ PCIE_LINK_CONTROL2_LINK_STATUS2_REG, reg);
+
+ /*
+ * Clear DIRECT_SPEED_CHANGE bit. It has been set by
+ * dw_pcie_setup_rc(pp). This bit causes link retraining. But
+ * link retraining should be performed later by calling the
+ * baikal_pcie_link_speed_fixup().
+ */
+ reg = dw_pcie_readl_dbi(pcie, PCIE_GEN2_CTRL_REG);
+ reg &= ~PCIE_DIRECT_SPEED_CHANGE;
+ dw_pcie_writel_dbi(pcie, PCIE_GEN2_CTRL_REG, reg);
+
+ /* Establish link */
+ regmap_read(rc->lcru, BAIKAL_LCRU_PCIE_GEN_CTL(rc->num), ®);
+ reg |= BAIKAL_PCIE_LTSSM_ENABLE;
+ regmap_write(rc->lcru, BAIKAL_LCRU_PCIE_GEN_CTL(rc->num), reg);
+
+ dw_pcie_wait_for_link(pcie);
+ }
+
+ regmap_read(rc->lcru, BAIKAL_LCRU_PCIE_MSI_TRANS_CTL2, ®);
+ reg &= ~BAIKAL_LCRU_PCIE_MSI_TRANS_CTL2_PCIE_RCNUM_MASK(rc->num);
+ reg |= BAIKAL_LCRU_PCIE_MSI_TRANS_CTL2_PCIE_RCNUM(rc->num);
+ reg |= BAIKAL_LCRU_PCIE_MSI_TRANS_CTL2_PCIE_MSI_TRANS_EN(rc->num);
+ regmap_write(rc->lcru, BAIKAL_LCRU_PCIE_MSI_TRANS_CTL2, reg);
+
+ return 0;
+}
+
+static const struct dw_pcie_host_ops baikal_pcie_host_ops = {
+ .host_init = baikal_pcie_host_init
+};
+
+static void baikal_pcie_link_print_status(struct baikal_pcie_rc *rc)
+{
+ struct dw_pcie *pcie = rc->pcie;
+ struct device *dev = pcie->dev;
+ u32 reg;
+ unsigned speed, width;
+
+ if (!baikal_pcie_link_up(pcie)) {
+ dev_info(dev, "link is down\n");
+ return;
+ }
+
+ reg = dw_pcie_readl_dbi(pcie, PCIE_LINK_CONTROL_LINK_STATUS_REG);
+ speed = (reg & PCIE_CAP_LINK_SPEED_MASK) >> PCIE_CAP_LINK_SPEED_SHIFT;
+ width = (reg & PCIE_CAP_NEGO_LINK_WIDTH_MASK) >>
+ PCIE_CAP_NEGO_LINK_WIDTH_SHIFT;
+
+ dev_info(dev, "link status is Gen%u%s, x%u\n", speed,
+ reg & PCIE_CAP_LINK_TRAINING ? " (training)" : "", width);
+}
+
+static unsigned baikal_pcie_link_is_training(struct baikal_pcie_rc *rc)
+{
+ struct dw_pcie *pcie = rc->pcie;
+ return dw_pcie_readl_dbi(pcie, PCIE_LINK_CONTROL_LINK_STATUS_REG) &
+ PCIE_CAP_LINK_TRAINING;
+}
+
+static bool baikal_pcie_link_wait_training_done(struct baikal_pcie_rc *rc)
+{
+ struct dw_pcie *pcie = rc->pcie;
+ struct device *dev = pcie->dev;
+ unsigned long start_jiffies = jiffies;
+
+ while (baikal_pcie_link_is_training(rc)) {
+ if (time_after(jiffies, start_jiffies + HZ)) {
+ dev_err(dev, "link training timeout occured\n");
+ return false;
+ }
+ udelay(100);
+ }
+ return true;
+}
+
+static void baikal_pcie_link_retrain(struct baikal_pcie_rc *rc,
+ int target_speed)
+{
+ struct dw_pcie *pcie = rc->pcie;
+ struct device *dev = pcie->dev;
+ u32 reg;
+ unsigned long start_jiffies;
+
+ dev_info(dev, "retrain link to Gen%u\n", target_speed);
+
+ /* In case link is already training wait for training to complete */
+ baikal_pcie_link_wait_training_done(rc);
+
+ /* Set desired speed */
+ reg = dw_pcie_readl_dbi(pcie, PCIE_LINK_CONTROL2_LINK_STATUS2_REG);
+ reg &= ~PCIE_CAP_TARGET_LINK_SPEED_MASK;
+ reg |= target_speed;
+ dw_pcie_writel_dbi(pcie, PCIE_LINK_CONTROL2_LINK_STATUS2_REG, reg);
+
+ /* Deassert and assert DIRECT_SPEED_CHANGE bit */
+ reg = dw_pcie_readl_dbi(pcie, PCIE_GEN2_CTRL_REG);
+ reg &= ~PCIE_DIRECT_SPEED_CHANGE;
+ dw_pcie_writel_dbi(pcie, PCIE_GEN2_CTRL_REG, reg);
+ reg |= PCIE_DIRECT_SPEED_CHANGE;
+ dw_pcie_writel_dbi(pcie, PCIE_GEN2_CTRL_REG, reg);
+
+ /* Wait for link training begin */
+ start_jiffies = jiffies;
+ while (!baikal_pcie_link_is_training(rc)) {
+ if (time_after(jiffies, start_jiffies + HZ)) {
+ dev_err(dev, "link training has not started\n");
+ /* Don't wait for training_done() if it hasn't started */
+ return;
+ }
+ udelay(100);
+ }
+
+ /* Wait for link training end */
+ if (!baikal_pcie_link_wait_training_done(rc)) {
+ return;
+ }
+
+ if (!dw_pcie_wait_for_link(pcie)) {
+ /* Wait if link has switched to configuration/recovery state */
+ baikal_pcie_link_wait_training_done(rc);
+ baikal_pcie_link_print_status(rc);
+ }
+}
+
+static void baikal_pcie_link_speed_fixup(struct pci_dev *pdev)
+{
+ struct dw_pcie_rp *pp = pdev->bus->sysdata;
+ struct dw_pcie *pcie = to_dw_pcie_from_pp(pp);
+ struct baikal_pcie_rc *rc = to_baikal_pcie_rc(pcie);
+ unsigned dev_lnkcap_speed;
+ unsigned dev_lnkcap_width;
+ unsigned rc_lnkcap_speed;
+ unsigned rc_lnksta_speed;
+ unsigned rc_target_speed;
+ u32 reg;
+
+ /* Skip Root Bridge */
+ if (!pdev->bus->self) {
+ return;
+ }
+
+ /* Skip any devices not directly connected to the RC */
+ if (pdev->bus->self->bus->number != pp->bridge->bus->number) {
+ return;
+ }
+
+ /* Skip if the bus has already been retrained */
+ if (rc->retrained) {
+ return;
+ }
+
+ reg = dw_pcie_readl_dbi(pcie, PCIE_LINK_CAPABILITIES_REG);
+ rc_lnkcap_speed = reg & PCI_EXP_LNKCAP_SLS;
+
+ reg = dw_pcie_readl_dbi(pcie, PCIE_LINK_CONTROL_LINK_STATUS_REG);
+ rc_lnksta_speed = (reg & PCIE_CAP_LINK_SPEED_MASK) >>
+ PCIE_CAP_LINK_SPEED_SHIFT;
+
+ pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, ®);
+ dev_lnkcap_speed = (reg & PCI_EXP_LNKCAP_SLS);
+ dev_lnkcap_width = (reg & PCI_EXP_LNKCAP_MLW) >>
+ PCI_EXP_LNKSTA_NLW_SHIFT;
+
+ baikal_pcie_link_print_status(rc);
+ dev_info(&pdev->dev, "device link capability is Gen%u, x%u\n",
+ dev_lnkcap_speed, dev_lnkcap_width);
+
+ /*
+ * Gen1->Gen3 is suitable way of retraining.
+ * Gen1->Gen2 is used when Gen3 could not be reached.
+ * Gen2->Gen3 causes system freezing sometimes.
+ */
+ if (rc_lnkcap_speed < dev_lnkcap_speed) {
+ rc_target_speed = rc_lnkcap_speed;
+ } else {
+ rc_target_speed = dev_lnkcap_speed;
+ }
+
+ while (rc_lnksta_speed < rc_target_speed) {
+ /* Try to change link speed */
+ baikal_pcie_link_retrain(rc, rc_target_speed);
+
+ /* Check if the link is down after retrain */
+ if (!baikal_pcie_link_up(pcie)) {
+ /*
+ * Check if the link has already been down and
+ * the link is not re-established at Gen1.
+ */
+ if (rc_lnksta_speed == 0 && rc_target_speed == 1) {
+ /* Unable to re-establish the link */
+ break;
+ }
+
+ rc_lnksta_speed = 0;
+ if (rc_target_speed > 1) {
+ /* Try to use lower speed */
+ --rc_target_speed;
+ }
+
+ continue;
+ }
+
+ reg = dw_pcie_readl_dbi(pcie,
+ PCIE_LINK_CONTROL_LINK_STATUS_REG);
+ rc_lnksta_speed = (reg & PCIE_CAP_LINK_SPEED_MASK) >>
+ PCIE_CAP_LINK_SPEED_SHIFT;
+ /* Check if the targeted speed has not been reached */
+ if (rc_lnksta_speed < rc_target_speed && rc_target_speed > 1) {
+ /* Try to use lower speed */
+ --rc_target_speed;
+ }
+ }
+
+ rc->retrained = true;
+}
+
+static void baikal_pcie_link_retrain_bus(const struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ baikal_pcie_link_speed_fixup(dev);
+ }
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ if (dev->subordinate) {
+ baikal_pcie_link_retrain_bus(dev->subordinate);
+ }
+ }
+}
+
+static irqreturn_t baikal_pcie_aer_irq_handler(int irq, void *arg)
+{
+ struct baikal_pcie_rc *rc = arg;
+ struct dw_pcie *pcie = rc->pcie;
+ struct device *dev = pcie->dev;
+ u32 corr_err_status;
+ u32 dev_ctrl_dev_status;
+ u32 root_err_status;
+ u32 uncorr_err_status;
+
+ uncorr_err_status = dw_pcie_readl_dbi(pcie,
+ PCIE_UNCORR_ERR_STATUS_REG);
+ corr_err_status = dw_pcie_readl_dbi(pcie,
+ PCIE_CORR_ERR_STATUS_REG);
+ root_err_status = dw_pcie_readl_dbi(pcie,
+ PCIE_ROOT_ERR_STATUS_REG);
+ dev_ctrl_dev_status = dw_pcie_readl_dbi(pcie,
+ PCIE_DEVICE_CONTROL_DEVICE_STATUS_REG);
+ dev_err(dev,
+ "dev_err:0x%x root_err:0x%x uncorr_err:0x%x corr_err:0x%x\n",
+ (dev_ctrl_dev_status & 0xf0000) >> 16,
+ root_err_status, uncorr_err_status, corr_err_status);
+
+ dw_pcie_writel_dbi(pcie,
+ PCIE_UNCORR_ERR_STATUS_REG, uncorr_err_status);
+ dw_pcie_writel_dbi(pcie,
+ PCIE_CORR_ERR_STATUS_REG, corr_err_status);
+ dw_pcie_writel_dbi(pcie,
+ PCIE_ROOT_ERR_STATUS_REG, root_err_status);
+ dw_pcie_writel_dbi(pcie,
+ PCIE_DEVICE_CONTROL_DEVICE_STATUS_REG, dev_ctrl_dev_status);
+
+ return IRQ_HANDLED;
+}
+
+static int baikal_pcie_add_pcie_port(struct baikal_pcie_rc *rc,
+ struct platform_device *pdev)
+{
+ struct dw_pcie *pcie = rc->pcie;
+ struct dw_pcie_rp *pp = &pcie->pp;
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ pp->irq = platform_get_irq(pdev, 0);
+ if (pp->irq < 0) {
+ return pp->irq;
+ }
+
+ ret = devm_request_irq(dev, pp->irq, baikal_pcie_aer_irq_handler,
+ IRQF_SHARED, "bm1000-pcie-aer", rc);
+
+ if (ret) {
+ dev_err(dev, "failed to request irq %d\n", pp->irq);
+ return ret;
+ }
+
+ if (IS_ENABLED(CONFIG_PCI_MSI)) {
+ pp->msi_irq[0] = platform_get_irq(pdev, 1);
+ if (pp->msi_irq[0] < 0) {
+ return pp->msi_irq[0];
+ }
+ }
+
+ pp->ops = &baikal_pcie_host_ops;
+
+ ret = dw_pcie_host_init(pp);
+ if (ret) {
+ dev_err(dev, "Failed to initialize host\n");
+ return ret;
+ }
+
+ baikal_pcie_link_retrain_bus(pp->bridge->bus);
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int baikal_pcie_pm_resume(struct device *dev)
+{
+ struct baikal_pcie_rc *rc = dev_get_drvdata(dev);
+ struct dw_pcie *pcie = rc->pcie;
+ u32 reg;
+
+ /* Set Memory Space Enable (MSE) bit */
+ reg = dw_pcie_readl_dbi(pcie, PCI_COMMAND);
+ reg |= PCI_COMMAND_MEMORY;
+ dw_pcie_writel_dbi(pcie, PCI_COMMAND, reg);
+ return 0;
+}
+
+static int baikal_pcie_pm_resume_noirq(struct device *dev)
+{
+ return 0;
+}
+
+static int baikal_pcie_pm_suspend(struct device *dev)
+{
+ struct baikal_pcie_rc *rc = dev_get_drvdata(dev);
+ struct dw_pcie *pcie = rc->pcie;
+ u32 reg;
+
+ /* Clear Memory Space Enable (MSE) bit */
+ reg = dw_pcie_readl_dbi(pcie, PCI_COMMAND);
+ reg &= ~PCI_COMMAND_MEMORY;
+ dw_pcie_writel_dbi(pcie, PCI_COMMAND, reg);
+ return 0;
+}
+
+static int baikal_pcie_pm_suspend_noirq(struct device *dev)
+{
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops baikal_pcie_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(baikal_pcie_pm_suspend,
+ baikal_pcie_pm_resume)
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(baikal_pcie_pm_suspend_noirq,
+ baikal_pcie_pm_resume_noirq)
+};
+
+static const struct of_device_id of_baikal_pcie_match[] = {
+ { .compatible = "baikal,bm1000-pcie" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, of_baikal_pcie_match);
+
+static const struct dw_pcie_ops baikal_pcie_ops = {
+ .link_up = baikal_pcie_link_up
+};
+
+static int baikal_pcie_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct baikal_pcie_rc *rc;
+ struct dw_pcie *pcie;
+ int ret;
+ u32 idx[2];
+ enum of_gpio_flags gpio_flags;
+ int reset_gpio;
+ struct resource *res;
+
+ if (!of_match_device(of_baikal_pcie_match, dev)) {
+ dev_err(dev, "device can't be handled by pcie-baikal\n");
+ return -EINVAL;
+ }
+
+ pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+ if (!pcie) {
+ return -ENOMEM;
+ }
+
+ pcie->dev = dev;
+ pcie->ops = &baikal_pcie_ops;
+
+ rc = devm_kzalloc(dev, sizeof(*rc), GFP_KERNEL);
+ if (!rc) {
+ return -ENOMEM;
+ }
+
+ rc->pcie = pcie;
+ rc->lcru = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "baikal,pcie-lcru");
+ if (IS_ERR(rc->lcru)) {
+ dev_err(dev, "No LCRU phandle specified\n");
+ rc->lcru = NULL;
+ return -EINVAL;
+ }
+
+ if (of_property_read_u32_array(dev->of_node, "baikal,pcie-lcru", idx, 2)) {
+ dev_err(dev, "failed to read LCRU\n");
+ rc->lcru = NULL;
+ return -EINVAL;
+ }
+
+ if (idx[1] > 2) {
+ dev_err(dev, "incorrect pcie-lcru index\n");
+ rc->lcru = NULL;
+ return -EINVAL;
+ }
+
+ rc->num = idx[1];
+ reset_gpio = of_get_named_gpio_flags(dev->of_node, "reset-gpios", 0,
+ &gpio_flags);
+ if (gpio_is_valid(reset_gpio)) {
+ rc->reset_gpio = gpio_to_desc(reset_gpio);
+ rc->reset_active_low = !!(gpio_flags & OF_GPIO_ACTIVE_LOW);
+ snprintf(rc->reset_name, sizeof(rc->reset_name), "pcie%u-reset",
+ rc->num);
+ } else {
+ rc->reset_gpio = NULL;
+ }
+
+ pm_runtime_enable(dev);
+ ret = pm_runtime_get_sync(dev);
+ if (ret < 0) {
+ dev_err(dev, "pm_runtime_get_sync failed\n");
+ goto err_pm_disable;
+ }
+
+ platform_set_drvdata(pdev, rc);
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+ if (res) {
+ devm_request_resource(dev, &iomem_resource, res);
+ pcie->dbi_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(pcie->dbi_base)) {
+ dev_err(dev, "error with ioremap\n");
+ ret = PTR_ERR(pcie->dbi_base);
+ goto err_pm_put;
+ }
+ } else {
+ dev_err(dev, "missing *dbi* reg space\n");
+ ret = -EINVAL;
+ goto err_pm_put;
+ }
+
+ ret = baikal_pcie_add_pcie_port(rc, pdev);
+ if (ret < 0) {
+ goto err_pm_put;
+ }
+
+ return 0;
+
+err_pm_put:
+ pm_runtime_put(dev);
+err_pm_disable:
+ pm_runtime_disable(dev);
+ return ret;
+}
+
+static struct platform_driver baikal_pcie_driver = {
+ .driver = {
+ .name = "baikal-pcie",
+ .of_match_table = of_baikal_pcie_match,
+ .suppress_bind_attrs = true,
+ .pm = &baikal_pcie_pm_ops
+ },
+ .probe = baikal_pcie_probe
+};
+
+module_platform_driver(baikal_pcie_driver);
+MODULE_DESCRIPTION("Baikal PCIe host controller driver");
+MODULE_LICENSE("GPL v2");
--
2.33.3
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