Re: [PATCH v4 5/6] PCI: fu740: Add SiFive FU740 PCIe host controller driver
From: Damien Le Moal <hidden>
Date: 2021-04-01 08:54:50
Also in:
linux-clk, linux-pci, linux-riscv, lkml
On 2021/04/01 15:02, Greentime Hu wrote:
quoted hunk ↗ jump to hunk
From: Paul Walmsley <redacted> Add driver for the SiFive FU740 PCIe host controller. This controller is based on the DesignWare PCIe core. Signed-off-by: Paul Walmsley <redacted> Co-developed-by: Henry Styles <redacted> Signed-off-by: Henry Styles <redacted> Co-developed-by: Erik Danie <redacted> Signed-off-by: Erik Danie <redacted> Co-developed-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@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.cdiff --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. + endmenudiff --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.odiff --git a/drivers/pci/controller/dwc/pcie-fu740.c b/drivers/pci/controller/dwc/pcie-fu740.c new file mode 100644 index 000000000000..ebbcbda97490 --- /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 *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_err(dev, "Wait for wait_ilde state failed!\n");
This is a void function. What is the point of these dev_err() if you do not return an error or process the failure in any way ? Change this to dev_warn() may be ?
+ + /* 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");
Same as above.
+}
+
+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;No need for this variable.
+
+ /* 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_reset(afp);
+
+ /* Enable pcieauxclk */
+ ret = clk_prepare_enable(afp->pcie_aux);
+ if (ret)
+ dev_err(dev, "unable to enable pcie_aux clock\n");No bailing out ? Without a clock, is this going to work ? If that is not a problem, then I would suggest a dev_warn() here.
+ + /* + * 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");
Same as above.
+
+ 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->reset = devm_gpiod_get_optional(dev, "reset-gpios", GPIOD_OUT_LOW);
+ if (IS_ERR(afp->reset)) {
+ dev_err(dev, "unable to get reset-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;Why not return dev_err_probe(...); ? Same for the returns above.
+ } + + /* 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;
You can simplify this with a simple: return dw_pcie_host_init(&pci->pp);
+
+ 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_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);-- Damien Le Moal Western Digital Research