[PATCH v4 5/6] PCI: fu740: Add SiFive FU740 PCIe host controller driver
Damien Le Moal
Damien.LeMoal at wdc.com
Thu Apr 1 09:51:14 BST 2021
On 2021/04/01 15:02, Greentime Hu wrote:
> From: Paul Walmsley <paul.walmsley at 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.walmsley at sifive.com>
> Co-developed-by: Henry Styles <hes at sifive.com>
> Signed-off-by: Henry Styles <hes at sifive.com>
> Co-developed-by: Erik Danie <erik.danie at sifive.com>
> Signed-off-by: Erik Danie <erik.danie at sifive.com>
> Co-developed-by: Greentime Hu <greentime.hu at sifive.com>
> Signed-off-by: Greentime Hu <greentime.hu at 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..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
More information about the linux-riscv
mailing list