From: Paul Walmsley <paul.walms...@sifive.com>

Add driver for the SiFive FU740 PCIe host controller.
This controller is based on the DesignWare PCIe core.

Signed-off-by: Paul Walmsley <paul.walms...@sifive.com>
Co-developed-by: Henry Styles <h...@sifive.com>
Signed-off-by: Henry Styles <h...@sifive.com>
Co-developed-by: Erik Danie <erik.da...@sifive.com>
Signed-off-by: Erik Danie <erik.da...@sifive.com>
Co-developed-by: Greentime Hu <greentime...@sifive.com>
Signed-off-by: Greentime Hu <greentime...@sifive.com>
---
 drivers/pci/controller/dwc/Kconfig      |   9 +
 drivers/pci/controller/dwc/Makefile     |   1 +
 drivers/pci/controller/dwc/pcie-fu740.c | 324 ++++++++++++++++++++++++
 3 files changed, 334 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pcie-fu740.c

diff --git a/drivers/pci/controller/dwc/Kconfig 
b/drivers/pci/controller/dwc/Kconfig
index 22c5529e9a65..0a37d21ed64e 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -318,4 +318,13 @@ config PCIE_AL
          required only for DT-based platforms. ACPI platforms with the
          Annapurna Labs PCIe controller don't need to enable this.
 
+config PCIE_FU740
+       bool "SiFive FU740 PCIe host controller"
+       depends on PCI_MSI_IRQ_DOMAIN
+       depends on SOC_SIFIVE || COMPILE_TEST
+       select PCIE_DW_HOST
+       help
+         Say Y here if you want PCIe controller support for the SiFive
+         FU740.
+
 endmenu
diff --git a/drivers/pci/controller/dwc/Makefile 
b/drivers/pci/controller/dwc/Makefile
index a751553fa0db..625f6aaeb5b8 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o
 obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
 obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
 obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
+obj-$(CONFIG_PCIE_FU740) += pcie-fu740.o
 obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
 obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
 obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone.o
diff --git a/drivers/pci/controller/dwc/pcie-fu740.c 
b/drivers/pci/controller/dwc/pcie-fu740.c
new file mode 100644
index 000000000000..65ca4c212fc3
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-fu740.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FU740 DesignWare PCIe Controller integration
+ * Copyright (C) 2019-2021 SiFive, Inc.
+ * Paul Walmsley
+ * Greentime Hu
+ *
+ * Based in part on the i.MX6 PCIe host controller shim which is:
+ *
+ * Copyright (C) 2013 Kosagi
+ *             https://www.kosagi.com
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/of_device.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/resource.h>
+#include <linux/signal.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/reset.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+
+#include "pcie-designware.h"
+
+#define to_fu740_pcie(x)       dev_get_drvdata((x)->dev)
+
+struct fu740_pcie {
+       struct dw_pcie pci;
+       void __iomem *mgmt_base;
+       struct gpio_desc *perstn;
+       struct gpio_desc *pwren;
+       struct clk *pcie_aux;
+       struct reset_control *rst;
+};
+
+#define SIFIVE_DEVICESRESETREG         0x28
+
+#define PCIEX8MGMT_PERST_N             0x0
+#define PCIEX8MGMT_APP_LTSSM_ENABLE    0x10
+#define PCIEX8MGMT_APP_HOLD_PHY_RST    0x18
+#define PCIEX8MGMT_DEVICE_TYPE         0x708
+#define PCIEX8MGMT_PHY0_CR_PARA_ADDR   0x860
+#define PCIEX8MGMT_PHY0_CR_PARA_RD_EN  0x870
+#define PCIEX8MGMT_PHY0_CR_PARA_RD_DATA        0x878
+#define PCIEX8MGMT_PHY0_CR_PARA_SEL    0x880
+#define PCIEX8MGMT_PHY0_CR_PARA_WR_DATA        0x888
+#define PCIEX8MGMT_PHY0_CR_PARA_WR_EN  0x890
+#define PCIEX8MGMT_PHY0_CR_PARA_ACK    0x898
+#define PCIEX8MGMT_PHY1_CR_PARA_ADDR   0x8a0
+#define PCIEX8MGMT_PHY1_CR_PARA_RD_EN  0x8b0
+#define PCIEX8MGMT_PHY1_CR_PARA_RD_DATA        0x8b8
+#define PCIEX8MGMT_PHY1_CR_PARA_SEL    0x8c0
+#define PCIEX8MGMT_PHY1_CR_PARA_WR_DATA        0x8c8
+#define PCIEX8MGMT_PHY1_CR_PARA_WR_EN  0x8d0
+#define PCIEX8MGMT_PHY1_CR_PARA_ACK    0x8d8
+
+#define PCIEX8MGMT_PHY_CDR_TRACK_EN    BIT(0)
+#define PCIEX8MGMT_PHY_LOS_THRSHLD     BIT(5)
+#define PCIEX8MGMT_PHY_TERM_EN         BIT(9)
+#define PCIEX8MGMT_PHY_TERM_ACDC       BIT(10)
+#define PCIEX8MGMT_PHY_EN              BIT(11)
+#define PCIEX8MGMT_PHY_INIT_VAL                (PCIEX8MGMT_PHY_CDR_TRACK_EN|\
+                                        PCIEX8MGMT_PHY_LOS_THRSHLD|\
+                                        PCIEX8MGMT_PHY_TERM_EN|\
+                                        PCIEX8MGMT_PHY_TERM_ACDC|\
+                                        PCIEX8MGMT_PHY_EN)
+
+#define PCIEX8MGMT_PHY_LANEN_DIG_ASIC_RX_OVRD_IN_3     0x1008
+#define PCIEX8MGMT_PHY_LANE_OFF                0x100
+#define PCIEX8MGMT_PHY_LANE0_BASE      
(PCIEX8MGMT_PHY_LANEN_DIG_ASIC_RX_OVRD_IN_3 + 0x100 * 0)
+#define PCIEX8MGMT_PHY_LANE1_BASE      
(PCIEX8MGMT_PHY_LANEN_DIG_ASIC_RX_OVRD_IN_3 + 0x100 * 1)
+#define PCIEX8MGMT_PHY_LANE2_BASE      
(PCIEX8MGMT_PHY_LANEN_DIG_ASIC_RX_OVRD_IN_3 + 0x100 * 2)
+#define PCIEX8MGMT_PHY_LANE3_BASE      
(PCIEX8MGMT_PHY_LANEN_DIG_ASIC_RX_OVRD_IN_3 + 0x100 * 3)
+
+static void fu740_pcie_assert_perstn(struct fu740_pcie *afp)
+{
+       /* Assert PERST_N GPIO */
+       gpiod_set_value_cansleep(afp->perstn, 0);
+       /* Assert controller PERST_N */
+       writel_relaxed(0x0, afp->mgmt_base + PCIEX8MGMT_PERST_N);
+}
+
+static void fu740_pcie_deassert_perstn(struct fu740_pcie *afp)
+{
+       /* Deassert controller PERST_N */
+       writel_relaxed(0x1, afp->mgmt_base + PCIEX8MGMT_PERST_N);
+       /* Deassert PERST_N GPIO */
+       gpiod_set_value_cansleep(afp->perstn, 1);
+}
+
+static void fu740_pcie_power_on(struct fu740_pcie *afp)
+{
+       gpiod_set_value_cansleep(afp->pwren, 1);
+       /*
+        * Ensure that PERST has been asserted for at least 100 ms.
+        * Section 2.2 of PCI Express Card Electromechanical Specification
+        * Revision 3.0
+        */
+       msleep(100);
+}
+
+static void fu740_pcie_drive_perstn(struct fu740_pcie *afp)
+{
+       fu740_pcie_assert_perstn(afp);
+       fu740_pcie_power_on(afp);
+       fu740_pcie_deassert_perstn(afp);
+}
+
+static void fu740_phyregwrite(const uint8_t phy, const uint16_t addr,
+                             const uint16_t wrdata, struct fu740_pcie *afp)
+{
+       struct device *dev = afp->pci.dev;
+       void __iomem *phy_cr_para_addr;
+       void __iomem *phy_cr_para_wr_data;
+       void __iomem *phy_cr_para_wr_en;
+       void __iomem *phy_cr_para_ack;
+       int ret, val;
+
+       /* Setup */
+       if (phy) {
+               phy_cr_para_addr = afp->mgmt_base + 
PCIEX8MGMT_PHY1_CR_PARA_ADDR;
+               phy_cr_para_wr_data = afp->mgmt_base + 
PCIEX8MGMT_PHY1_CR_PARA_WR_DATA;
+               phy_cr_para_wr_en = afp->mgmt_base + 
PCIEX8MGMT_PHY1_CR_PARA_WR_EN;
+               phy_cr_para_ack = afp->mgmt_base + PCIEX8MGMT_PHY1_CR_PARA_ACK;
+       } else {
+               phy_cr_para_addr = afp->mgmt_base + 
PCIEX8MGMT_PHY0_CR_PARA_ADDR;
+               phy_cr_para_wr_data = afp->mgmt_base + 
PCIEX8MGMT_PHY0_CR_PARA_WR_DATA;
+               phy_cr_para_wr_en = afp->mgmt_base + 
PCIEX8MGMT_PHY0_CR_PARA_WR_EN;
+               phy_cr_para_ack = afp->mgmt_base + PCIEX8MGMT_PHY0_CR_PARA_ACK;
+       }
+
+       writel_relaxed(addr, phy_cr_para_addr);
+       writel_relaxed(wrdata, phy_cr_para_wr_data);
+       writel_relaxed(1, phy_cr_para_wr_en);
+
+       /* Wait for wait_idle */
+       ret = readl_poll_timeout(phy_cr_para_ack, val, val, 10, 5000);
+       if (ret)
+               dev_err(dev, "Wait for wait_ilde state failed!\n");
+
+       /* Clear */
+       writel_relaxed(0, phy_cr_para_wr_en);
+
+       /* Wait for ~wait_idle */
+       ret = readl_poll_timeout(phy_cr_para_ack, val, !val, 10, 5000);
+       if (ret)
+               dev_err(dev, "Wait for !wait_ilde state failed!\n");
+}
+
+static void fu740_pcie_init_phy(struct fu740_pcie *afp)
+{
+       /* Enable phy cr_para_sel interfaces */
+       writel_relaxed(0x1, afp->mgmt_base + PCIEX8MGMT_PHY0_CR_PARA_SEL);
+       writel_relaxed(0x1, afp->mgmt_base + PCIEX8MGMT_PHY1_CR_PARA_SEL);
+
+       /*
+        * Wait 10 cr_para cycles to guarantee that the registers are ready
+        * to be edited.
+        */
+       ndelay(10);
+
+       /* Set PHY AC termination mode */
+       fu740_phyregwrite(0, PCIEX8MGMT_PHY_LANE0_BASE, 
PCIEX8MGMT_PHY_INIT_VAL, afp);
+       fu740_phyregwrite(0, PCIEX8MGMT_PHY_LANE1_BASE, 
PCIEX8MGMT_PHY_INIT_VAL, afp);
+       fu740_phyregwrite(0, PCIEX8MGMT_PHY_LANE2_BASE, 
PCIEX8MGMT_PHY_INIT_VAL, afp);
+       fu740_phyregwrite(0, PCIEX8MGMT_PHY_LANE3_BASE, 
PCIEX8MGMT_PHY_INIT_VAL, afp);
+       fu740_phyregwrite(1, PCIEX8MGMT_PHY_LANE0_BASE, 
PCIEX8MGMT_PHY_INIT_VAL, afp);
+       fu740_phyregwrite(1, PCIEX8MGMT_PHY_LANE1_BASE, 
PCIEX8MGMT_PHY_INIT_VAL, afp);
+       fu740_phyregwrite(1, PCIEX8MGMT_PHY_LANE2_BASE, 
PCIEX8MGMT_PHY_INIT_VAL, afp);
+       fu740_phyregwrite(1, PCIEX8MGMT_PHY_LANE3_BASE, 
PCIEX8MGMT_PHY_INIT_VAL, afp);
+}
+
+static void fu740_pcie_ltssm_enable(struct device *dev)
+{
+       struct fu740_pcie *afp = dev_get_drvdata(dev);
+
+       /* Enable LTSSM */
+       writel_relaxed(0x1, afp->mgmt_base + PCIEX8MGMT_APP_LTSSM_ENABLE);
+}
+
+static int fu740_pcie_start_link(struct dw_pcie *pci)
+{
+       struct device *dev = pci->dev;
+
+       /* Start LTSSM. */
+       fu740_pcie_ltssm_enable(dev);
+       return 0;
+}
+
+static int fu740_pcie_host_init(struct pcie_port *pp)
+{
+       struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+       struct fu740_pcie *afp = to_fu740_pcie(pci);
+       struct device *dev = pci->dev;
+       int ret;
+
+       /* Power on reset */
+       fu740_pcie_drive_perstn(afp);
+
+       /* Enable pcieauxclk */
+       ret = clk_prepare_enable(afp->pcie_aux);
+       if (ret)
+               dev_err(dev, "unable to enable pcie_aux clock\n");
+
+       /*
+        * Assert hold_phy_rst (hold the controller LTSSM in reset after
+        * power_up_rst_n for register programming with cr_para)
+        */
+       writel_relaxed(0x1, afp->mgmt_base + PCIEX8MGMT_APP_HOLD_PHY_RST);
+
+       /* Deassert power_up_rst_n */
+       ret = reset_control_deassert(afp->rst);
+       if (ret)
+               dev_err(dev, "unable to deassert pcie_power_up_rst_n\n");
+
+       fu740_pcie_init_phy(afp);
+
+       /* Disable pcieauxclk */
+       clk_disable_unprepare(afp->pcie_aux);
+       /* Clear hold_phy_rst */
+       writel_relaxed(0x0, afp->mgmt_base + PCIEX8MGMT_APP_HOLD_PHY_RST);
+       /* Enable pcieauxclk */
+       ret = clk_prepare_enable(afp->pcie_aux);
+       /* Set RC mode */
+       writel_relaxed(0x4, afp->mgmt_base + PCIEX8MGMT_DEVICE_TYPE);
+
+       return 0;
+}
+
+static const struct dw_pcie_host_ops fu740_pcie_host_ops = {
+       .host_init = fu740_pcie_host_init,
+};
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+       .start_link = fu740_pcie_start_link,
+};
+
+static int fu740_pcie_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct dw_pcie *pci;
+       struct fu740_pcie *afp;
+       int ret;
+
+       afp = devm_kzalloc(dev, sizeof(*afp), GFP_KERNEL);
+       if (!afp)
+               return -ENOMEM;
+       pci = &afp->pci;
+       pci->dev = dev;
+       pci->ops = &dw_pcie_ops;
+       pci->pp.ops = &fu740_pcie_host_ops;
+
+       /* SiFive specific region: mgmt */
+       afp->mgmt_base = devm_platform_ioremap_resource_byname(pdev, "mgmt");
+       if (IS_ERR(afp->mgmt_base))
+               return PTR_ERR(afp->mgmt_base);
+
+       /* Fetch GPIOs */
+       afp->perstn = devm_gpiod_get_optional(dev, "perstn-gpios", 
GPIOD_OUT_LOW);
+       if (IS_ERR(afp->perstn)) {
+               dev_err(dev, "unable to get perstn-gpios\n");
+               return ret;
+       }
+       afp->pwren = devm_gpiod_get_optional(dev, "pwren-gpios", GPIOD_OUT_LOW);
+       if (IS_ERR(afp->pwren)) {
+               dev_err(dev, "unable to get pwren-gpios\n");
+               return ret;
+       }
+
+       /* Fetch clocks */
+       afp->pcie_aux = devm_clk_get(dev, "pcie_aux");
+       if (IS_ERR(afp->pcie_aux))
+               return dev_err_probe(dev, PTR_ERR(afp->pcie_aux),
+                                            "pcie_aux clock source missing or 
invalid\n");
+
+       /* Fetch reset */
+       afp->rst = devm_reset_control_get_exclusive(dev, NULL);
+       if (IS_ERR(afp->rst))
+               return dev_err_probe(dev, PTR_ERR(afp->rst), "unable to get 
reset\n");
+
+       platform_set_drvdata(pdev, afp);
+
+       ret = dw_pcie_host_init(&pci->pp);
+       if (ret < 0)
+               return ret;
+
+       return 0;
+}
+
+static void fu740_pcie_shutdown(struct platform_device *pdev)
+{
+       struct fu740_pcie *afp = platform_get_drvdata(pdev);
+
+       /* Bring down link, so bootloader gets clean state in case of reboot */
+       fu740_pcie_assert_perstn(afp);
+}
+
+static const struct of_device_id fu740_pcie_of_match[] = {
+       { .compatible = "sifive,fu740-pcie", },
+       {},
+};
+
+static struct platform_driver fu740_pcie_driver = {
+       .driver = {
+                  .name = "fu740-pcie",
+                  .of_match_table = fu740_pcie_of_match,
+                  .suppress_bind_attrs = true,
+       },
+       .probe = fu740_pcie_probe,
+       .shutdown = fu740_pcie_shutdown,
+};
+
+builtin_platform_driver(fu740_pcie_driver);
-- 
2.30.2

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