[PATCH v6 5/6] PCI: fu740: Add SiFive FU740 PCIe host controller driver

From: Greentime Hu
Date: Tue May 04 2021 - 07:00:55 EST

From: Paul Walmsley <paul.walmsley@xxxxxxxxxx>

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

Signed-off-by: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Co-developed-by: Henry Styles <hes@xxxxxxxxxx>
Signed-off-by: Henry Styles <hes@xxxxxxxxxx>
Co-developed-by: Erik Danie <erik.danie@xxxxxxxxxx>
Signed-off-by: Erik Danie <erik.danie@xxxxxxxxxx>
Co-developed-by: Greentime Hu <greentime.hu@xxxxxxxxxx>
Signed-off-by: Greentime Hu <greentime.hu@xxxxxxxxxx>
---
drivers/pci/controller/dwc/Kconfig | 10 +
drivers/pci/controller/dwc/Makefile | 1 +
drivers/pci/controller/dwc/pcie-fu740.c | 309 ++++++++++++++++++++++++
3 files changed, 320 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..255d43b1661b 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -318,4 +318,14 @@ 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
+ depends on GPIOLIB
+ 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..00cde9a248b5
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-fu740.c
@@ -0,0 +1,309 @@
+// 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/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/resource.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/reset.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 *reset;
+ 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_reset(struct fu740_pcie *afp)
+{
+ /* Assert PERST_N GPIO */
+ gpiod_set_value_cansleep(afp->reset, 0);
+ /* Assert controller PERST_N */
+ writel_relaxed(0x0, afp->mgmt_base + PCIEX8MGMT_PERST_N);
+}
+
+static void fu740_pcie_deassert_reset(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->reset, 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_reset(struct fu740_pcie *afp)
+{
+ fu740_pcie_assert_reset(afp);
+ fu740_pcie_power_on(afp);
+ fu740_pcie_deassert_reset(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_warn(dev, "Wait for wait_idle 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_warn(dev, "Wait for !wait_idle 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 int fu740_pcie_start_link(struct dw_pcie *pci)
+{
+ struct device *dev = pci->dev;
+ struct fu740_pcie *afp = dev_get_drvdata(dev);
+
+ /* Enable LTSSM */
+ writel_relaxed(0x1, afp->mgmt_base + PCIEX8MGMT_APP_LTSSM_ENABLE);
+ 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_reset(afp);
+
+ /* Enable pcieauxclk */
+ ret = clk_prepare_enable(afp->pcie_aux);
+ if (ret) {
+ dev_err(dev, "unable to enable pcie_aux clock\n");
+ return ret;
+ }
+
+ /*
+ * 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");
+ return ret;
+ }
+
+ 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;
+
+ 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->reset = devm_gpiod_get_optional(dev, "reset-gpios", GPIOD_OUT_LOW);
+ if (IS_ERR(afp->reset))
+ return dev_err_probe(dev, PTR_ERR(afp->reset), "unable to get reset-gpios\n");
+
+ afp->pwren = devm_gpiod_get_optional(dev, "pwren-gpios", GPIOD_OUT_LOW);
+ if (IS_ERR(afp->pwren))
+ return dev_err_probe(dev, PTR_ERR(afp->pwren), "unable to get pwren-gpios\n");
+
+ /* 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);
+
+ return dw_pcie_host_init(&pci->pp);
+}
+
+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_reset(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);
--
2.31.1