| Message ID | 34c2c3985443b23a75ce89c605c4b833bbafd134.1614681831.git.greentime.hu@sifive.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add SiFive FU740 PCIe host controller driver support | expand |
On Tue, Mar 2, 2021 at 4:59 AM Greentime Hu <greentime.hu@sifive.com> wrote: > > From: Paul Walmsley <paul.walmsley@sifive.com> > > Add driver for the SiFive FU740 PCIe host controller. > This controller is based on the DesignWare PCIe core. > > Co-developed-by: Henry Styles <hes@sifive.com> > Signed-off-by: Henry Styles <hes@sifive.com> > Co-developed-by: Erik Danie <erik.danie@sifive.com> > Signed-off-by: Erik Danie <erik.danie@sifive.com> > Co-developed-by: Greentime Hu <greentime.hu@sifive.com> > Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Your Sob should be last since you are sending the patch. > Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> And Paul's either before yours or first in the list depending on the history. > --- > drivers/pci/controller/dwc/Kconfig | 9 + > drivers/pci/controller/dwc/Makefile | 1 + > drivers/pci/controller/dwc/pcie-fu740.c | 455 ++++++++++++++++++++++++ > 3 files changed, 465 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..6916eea40ea5 > --- /dev/null > +++ b/drivers/pci/controller/dwc/pcie-fu740.c > @@ -0,0 +1,455 @@ > +// 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/regmap.h> > +#include <linux/regulator/consumer.h> > +#include <linux/resource.h> > +#include <linux/signal.h> > +#include <linux/types.h> > +#include <linux/interrupt.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; > + int perstn_gpio; > + int pwren_gpio; Use gpio descriptors and the gpiod_* api. > + 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 I tend to think we should split the phy part to a proper phy driver. Just because the registers happen to be in the same register space isn't really a good reason to combine them. > + > +/* PCIe Port Logic registers (memory-mapped) */ > +#define PL_OFFSET 0x700 That's all DWC controllers. > +#define PCIE_PL_GEN2_CTRL_OFF (PL_OFFSET + 0x10c) Also common. Pretty sure there's a define already. > +#define PCIE_PL_DIRECTED_SPEED_CHANGE_OFF 0x20000 > + > +#define PCIE_PHY_MAX_RETRY_CNT 1000 > + > +static void fu740_pcie_assert_perstn(struct fu740_pcie *afp) > +{ > + /* PERST_N GPIO */ > + if (gpio_is_valid(afp->perstn_gpio)) > + gpio_direction_output(afp->perstn_gpio, 0); > + > + /* Controller PERST_N */ > + __raw_writel(0x0, afp->mgmt_base + PCIEX8MGMT_PERST_N); writel_relaxed is the preferred variant. > +} > + > +static void fu740_pcie_deassert_perstn(struct fu740_pcie *afp) > +{ > + /* Controller PERST_N */ > + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_PERST_N); > + /* PERST_N GPIO */ > + if (gpio_is_valid(afp->perstn_gpio)) > + gpio_direction_output(afp->perstn_gpio, 1); > +} > + > +static void fu740_pcie_power_on(struct fu740_pcie *afp) > +{ > + if (gpio_is_valid(afp->pwren_gpio)) { > + gpio_direction_output(afp->pwren_gpio, 1); > + mdelay(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_phyregreadwrite(const uint8_t phy, const uint8_t write, > + const uint16_t addr, > + const uint16_t wrdata, uint16_t *rddata, > + struct fu740_pcie *afp) I think you should split this into separate read and write functions. > +{ > + unsigned char ack = 0; > + unsigned int cnt = 0; > + struct device *dev = afp->pci->dev; > + > + /* setup */ > + __raw_writel(addr, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_ADDR : > + PCIEX8MGMT_PHY0_CR_PARA_ADDR)); > + if (write) > + __raw_writel(wrdata, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_DATA : > + PCIEX8MGMT_PHY0_CR_PARA_WR_DATA)); > + if (write) > + __raw_writel(1, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_EN : > + PCIEX8MGMT_PHY0_CR_PARA_WR_EN)); > + else > + __raw_writel(1, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_RD_EN : > + PCIEX8MGMT_PHY0_CR_PARA_RD_EN)); > + > + /* wait for wait_idle */ > + do { > + if (__raw_readl > + (afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_ACK : > + PCIEX8MGMT_PHY0_CR_PARA_ACK))) { > + ack = 1; > + if (!write) > + __raw_readl(afp->mgmt_base + > + (phy ? > + PCIEX8MGMT_PHY1_CR_PARA_RD_DATA : > + PCIEX8MGMT_PHY0_CR_PARA_RD_DATA)); > + } > + } while (!ack); > + > + /* clear */ > + if (write) > + __raw_writel(0, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_EN : > + PCIEX8MGMT_PHY0_CR_PARA_WR_EN)); > + else > + __raw_writel(0, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_RD_EN : > + PCIEX8MGMT_PHY0_CR_PARA_RD_EN)); > + > + /* wait for ~wait_idle */ > + while (__raw_readl > + (afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_ACK : > + PCIEX8MGMT_PHY0_CR_PARA_ACK))) { > + cpu_relax(); > + cnt++; > + if (cnt > PCIE_PHY_MAX_RETRY_CNT) { > + dev_err(dev, "PCIE phy doesn't enter idle state.\n"); > + break; > + } > + } We have helpers for this kind of loop. > +} > + > +static void fu740_pcie_init_phy(struct fu740_pcie *afp) > +{ > + int lane; > + > + /* enable phy cr_para_sel interfaces */ > + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_PHY0_CR_PARA_SEL); > + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_PHY1_CR_PARA_SEL); > + > + /* wait 10 cr_para cycles */ > + msleep(1); > + > + /* set PHY AC termination mode */ > + for (lane = 0; lane < 4; lane++) { > + fu740_phyregreadwrite(0, 1, > + 0x1008 + (0x100 * lane), > + 0x0e21, NULL, afp); > + fu740_phyregreadwrite(1, 1, > + 0x1008 + (0x100 * lane), > + 0x0e21, NULL, afp); > + } > + > +} > + > +static void fu740_pcie_ltssm_enable(struct device *dev) > +{ > + struct fu740_pcie *afp = dev_get_drvdata(dev); > + > + /* Enable LTSSM */ > + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_APP_LTSSM_ENABLE); > +} > + > +static int fu740_pcie_start_link(struct dw_pcie *pci) > +{ > + struct device *dev = pci->dev; > + u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > + u32 tmp; > + int ret; > + > + /* > + * Force Gen1 operation when starting the link. In case the link is > + * started in Gen2 mode, there is a possibility the devices on the > + * bus will not be detected at all. This happens with PCIe switches. > + */ > + dw_pcie_dbi_ro_wr_en(pci); > + tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); > + tmp &= ~PCI_EXP_LNKCAP_SLS; > + tmp |= PCI_EXP_LNKCAP_SLS_2_5GB; > + dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp); > + dw_pcie_dbi_ro_wr_dis(pci); > + > + /* Start LTSSM. */ > + fu740_pcie_ltssm_enable(dev); > + > + ret = dw_pcie_wait_for_link(pci); > + if (ret) > + goto err_reset_phy; > + > + /* Now set it to operate in Gen3 */ > + dw_pcie_dbi_ro_wr_en(pci); > + tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); > + tmp &= ~PCI_EXP_LNKCAP_SLS; > + tmp |= PCI_EXP_LNKCAP_SLS_8_0GB; You don't support slower speeds? We have some common DWC handling of this too, that doesn't work? > + dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp); > + /* Enable DIRECTED SPEED CHANGE bit of GEN2_CTRL_OFF register */ > + tmp = dw_pcie_readl_dbi(pci, PCIE_PL_GEN2_CTRL_OFF); > + tmp |= PCIE_PL_DIRECTED_SPEED_CHANGE_OFF; > + dw_pcie_writel_dbi(pci, PCIE_PL_GEN2_CTRL_OFF, tmp); > + dw_pcie_dbi_ro_wr_dis(pci); > + > + ret = dw_pcie_wait_for_link(pci); > + if (ret) > + goto err_reset_phy; > + > + /* > + * Reenable DIRECTED SPEED CHANGE. > + * > + * You need to set this bit after each speed change, but after > + * reaching G1, setting it once doesn't seem to work (it reaches G3 > + * equalization states and then times out, falls back to G1). But > + * If after that, you set it again, it then reaches G3 perfectly > + * fine. > + */ > + dw_pcie_dbi_ro_wr_en(pci); > + tmp = dw_pcie_readl_dbi(pci, PCIE_PL_GEN2_CTRL_OFF); > + tmp |= PCIE_PL_DIRECTED_SPEED_CHANGE_OFF; > + dw_pcie_writel_dbi(pci, PCIE_PL_GEN2_CTRL_OFF, tmp); > + dw_pcie_dbi_ro_wr_dis(pci); > + > + ret = dw_pcie_wait_for_link(pci); The DWC core does this after start_link() now. > + if (ret) > + goto err_reset_phy; > + > + tmp = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); > + dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS); If we want this, it should be common. > + return 0; > + > + err_reset_phy: > + dev_err(dev, "Failed to bring link up!\n" > + "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n", > + dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0), > + dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1)); > + return ret; > +} > + > +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 = 0; > + > + /* 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) > + */ > + __raw_writel(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 */ > + __raw_writel(0x0, afp->mgmt_base + PCIEX8MGMT_APP_HOLD_PHY_RST); > + /* enable pcieauxclk */ > + ret = clk_prepare_enable(afp->pcie_aux); > + /* set RC mode */ > + __raw_writel(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 const struct dev_pm_ops fu740_pcie_pm_ops = { > + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(fu740_pcie_suspend_noirq, > + fu740_pcie_resume_noirq) > +}; > + > +static int fu740_pcie_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct dw_pcie *pci; > + struct fu740_pcie *afp; > + struct resource *mgmt_res; > + struct device_node *node = dev->of_node; > + int ret; > + u16 val; > + > + afp = devm_kzalloc(dev, sizeof(*afp), GFP_KERNEL); > + if (!afp) > + return -ENOMEM; > + > + pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL); Embed dw_pcie in fu740_pcie and do 1 alloc. > + if (!pci) > + return -ENOMEM; > + > + pci->dev = dev; > + pci->ops = &dw_pcie_ops; > + pci->pp.ops = &fu740_pcie_host_ops; > + > + afp->pci = pci; > + > + mgmt_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mgmt"); > + if (!mgmt_res) { > + dev_warn(dev, "missing required mgmt address range"); > + return -ENOENT; > + } > + afp->mgmt_base = devm_ioremap_resource(dev, mgmt_res); Use devm_platform_ioremap_resource_byname > + if (IS_ERR(afp->mgmt_base)) > + return PTR_ERR(afp->mgmt_base); > + > + /* Fetch GPIOs */ > + afp->perstn_gpio = of_get_named_gpio(node, "perstn-gpios", 0); > + if (gpio_is_valid(afp->perstn_gpio)) { > + ret = devm_gpio_request_one(dev, afp->perstn_gpio, > + GPIOF_OUT_INIT_LOW, "perstn-gpios"); > + if (ret) { > + dev_err(dev, "unable to get perstn gpio\n"); > + return ret; > + } > + } else if (afp->perstn_gpio == -EPROBE_DEFER) { > + dev_err(dev, "perst-gpios EPROBE_DEFER\n"); > + return afp->perstn_gpio; > + } GPIOs are optional? That's not what the binding says. > + > + afp->pwren_gpio = of_get_named_gpio(node, "pwren-gpios", 0); > + if (gpio_is_valid(afp->pwren_gpio)) { > + ret = devm_gpio_request_one(dev, afp->pwren_gpio, > + GPIOF_OUT_INIT_LOW, "pwren-gpios"); > + if (ret) { > + dev_err(dev, "unable to get pwren gpio\n"); > + return ret; > + } > + } else if (afp->pwren_gpio == -EPROBE_DEFER) { > + dev_err(dev, "pwren-gpios EPROBE_DEFER\n"); > + return afp->pwren_gpio; > + } > + > + /* 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(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; > + > + if (pci_msi_enabled()) { > + u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI); > + > + val = dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS); > + val |= PCI_MSI_FLAGS_ENABLE; > + dw_pcie_writew_dbi(pci, offset + PCI_MSI_FLAGS, val); Are you sure this is needed? It's suspect that only i.MX6 needs it. > + } > + > + 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, > + .pm = &fu740_pcie_pm_ops, > + }, > + .probe = fu740_pcie_probe, > + .shutdown = fu740_pcie_shutdown, > +}; > + > +static int __init fu740_pcie_init(void) > +{ > + return platform_driver_register(&fu740_pcie_driver); > +} > + > +device_initcall(fu740_pcie_init); Needs to be early? Why?
On Tue, 2021-03-02 at 18:59 +0800, Greentime Hu wrote: [...] > +static int fu740_pcie_probe(struct platform_device *pdev) > +{ [...] > + /* Fetch reset */ > + afp->rst = devm_reset_control_get(dev, NULL); Please use afp->rst = devm_reset_control_get_exclusive(dev, NULL); regards Philipp
Make the subject like this: PCI: fu740: Add SiFive FU740 PCIe host controller driver since you're adding a "fu740" driver, not a "designware" driver. Future commits will then look like: PCI: fu740: ... On Tue, Mar 02, 2021 at 06:59:16PM +0800, Greentime Hu wrote: > From: Paul Walmsley <paul.walmsley@sifive.com> > > Add driver for the SiFive FU740 PCIe host controller. > This controller is based on the DesignWare PCIe core. > > Co-developed-by: Henry Styles <hes@sifive.com> > Signed-off-by: Henry Styles <hes@sifive.com> > Co-developed-by: Erik Danie <erik.danie@sifive.com> > Signed-off-by: Erik Danie <erik.danie@sifive.com> > Co-developed-by: Greentime Hu <greentime.hu@sifive.com> > Signed-off-by: Greentime Hu <greentime.hu@sifive.com> > Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> > --- > drivers/pci/controller/dwc/Kconfig | 9 + > drivers/pci/controller/dwc/Makefile | 1 + > drivers/pci/controller/dwc/pcie-fu740.c | 455 ++++++++++++++++++++++++ > 3 files changed, 465 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..6916eea40ea5 > --- /dev/null > +++ b/drivers/pci/controller/dwc/pcie-fu740.c > @@ -0,0 +1,455 @@ > +// 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/regmap.h> > +#include <linux/regulator/consumer.h> > +#include <linux/resource.h> > +#include <linux/signal.h> > +#include <linux/types.h> > +#include <linux/interrupt.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; > + int perstn_gpio; > + int pwren_gpio; > + 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 > + > +/* PCIe Port Logic registers (memory-mapped) */ > +#define PL_OFFSET 0x700 > +#define PCIE_PL_GEN2_CTRL_OFF (PL_OFFSET + 0x10c) > +#define PCIE_PL_DIRECTED_SPEED_CHANGE_OFF 0x20000 > + > +#define PCIE_PHY_MAX_RETRY_CNT 1000 > + > +static void fu740_pcie_assert_perstn(struct fu740_pcie *afp) > +{ > + /* PERST_N GPIO */ > + if (gpio_is_valid(afp->perstn_gpio)) > + gpio_direction_output(afp->perstn_gpio, 0); > + > + /* Controller PERST_N */ > + __raw_writel(0x0, afp->mgmt_base + PCIEX8MGMT_PERST_N); > +} > + > +static void fu740_pcie_deassert_perstn(struct fu740_pcie *afp) > +{ > + /* Controller PERST_N */ > + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_PERST_N); > + /* PERST_N GPIO */ > + if (gpio_is_valid(afp->perstn_gpio)) > + gpio_direction_output(afp->perstn_gpio, 1); > +} > + > +static void fu740_pcie_power_on(struct fu740_pcie *afp) > +{ > + if (gpio_is_valid(afp->pwren_gpio)) { > + gpio_direction_output(afp->pwren_gpio, 1); > + mdelay(100); Can you add a note about where the 100ms value comes from? > + } > +} > + > +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_phyregreadwrite(const uint8_t phy, const uint8_t write, > + const uint16_t addr, > + const uint16_t wrdata, uint16_t *rddata, > + struct fu740_pcie *afp) > +{ > + unsigned char ack = 0; > + unsigned int cnt = 0; > + struct device *dev = afp->pci->dev; > + > + /* setup */ Most of your single-line comments start with a capital letter. It's nice if they all use the same style. > + __raw_writel(addr, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_ADDR : > + PCIEX8MGMT_PHY0_CR_PARA_ADDR)); All these "phy ? x : y" expressions are really ugly and maybe could be factored out ahead of time. > + if (write) > + __raw_writel(wrdata, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_DATA : > + PCIEX8MGMT_PHY0_CR_PARA_WR_DATA)); > + if (write) > + __raw_writel(1, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_EN : > + PCIEX8MGMT_PHY0_CR_PARA_WR_EN)); > + else > + __raw_writel(1, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_RD_EN : > + PCIEX8MGMT_PHY0_CR_PARA_RD_EN)); > + > + /* wait for wait_idle */ > + do { > + if (__raw_readl > + (afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_ACK : > + PCIEX8MGMT_PHY0_CR_PARA_ACK))) { > + ack = 1; > + if (!write) > + __raw_readl(afp->mgmt_base + > + (phy ? > + PCIEX8MGMT_PHY1_CR_PARA_RD_DATA : > + PCIEX8MGMT_PHY0_CR_PARA_RD_DATA)); > + } > + } while (!ack); Possible infinite loop. We should try to avoid depending on hardware doing the right thing. If the hardware breaks or is removed, we don't want to hang. > + /* clear */ > + if (write) > + __raw_writel(0, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_EN : > + PCIEX8MGMT_PHY0_CR_PARA_WR_EN)); > + else > + __raw_writel(0, > + afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_RD_EN : > + PCIEX8MGMT_PHY0_CR_PARA_RD_EN)); > + > + /* wait for ~wait_idle */ > + while (__raw_readl > + (afp->mgmt_base + > + (phy ? PCIEX8MGMT_PHY1_CR_PARA_ACK : > + PCIEX8MGMT_PHY0_CR_PARA_ACK))) { > + cpu_relax(); > + cnt++; > + if (cnt > PCIE_PHY_MAX_RETRY_CNT) { > + dev_err(dev, "PCIE phy doesn't enter idle state.\n"); > + break; > + } > + } > +} > + > +static void fu740_pcie_init_phy(struct fu740_pcie *afp) > +{ > + int lane; > + > + /* enable phy cr_para_sel interfaces */ > + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_PHY0_CR_PARA_SEL); > + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_PHY1_CR_PARA_SEL); > + > + /* wait 10 cr_para cycles */ > + msleep(1); A reference to the spec section that requires the 1ms would be helpful. > + /* set PHY AC termination mode */ > + for (lane = 0; lane < 4; lane++) { > + fu740_phyregreadwrite(0, 1, > + 0x1008 + (0x100 * lane), > + 0x0e21, NULL, afp); > + fu740_phyregreadwrite(1, 1, > + 0x1008 + (0x100 * lane), > + 0x0e21, NULL, afp); Rewrap to use more of the 80-column line. Each will fit on two lines. Maybe add #defines for the 0x1008, 0x100, 0x0e21 magic numbers? Could compute the "0x1008 + (0x100 * lane)" expression once instead of repeating it. > + } > + > +} > + > +static void fu740_pcie_ltssm_enable(struct device *dev) > +{ > + struct fu740_pcie *afp = dev_get_drvdata(dev); > + > + /* Enable LTSSM */ > + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_APP_LTSSM_ENABLE); > +} > + > +static int fu740_pcie_start_link(struct dw_pcie *pci) > +{ > + struct device *dev = pci->dev; > + u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > + u32 tmp; > + int ret; > + > + /* > + * Force Gen1 operation when starting the link. In case the link is > + * started in Gen2 mode, there is a possibility the devices on the > + * bus will not be detected at all. This happens with PCIe switches. > + */ > + dw_pcie_dbi_ro_wr_en(pci); > + tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); > + tmp &= ~PCI_EXP_LNKCAP_SLS; > + tmp |= PCI_EXP_LNKCAP_SLS_2_5GB; > + dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp); > + dw_pcie_dbi_ro_wr_dis(pci); > + > + /* Start LTSSM. */ > + fu740_pcie_ltssm_enable(dev); > + > + ret = dw_pcie_wait_for_link(pci); > + if (ret) > + goto err_reset_phy; > + > + /* Now set it to operate in Gen3 */ > + dw_pcie_dbi_ro_wr_en(pci); > + tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); > + tmp &= ~PCI_EXP_LNKCAP_SLS; > + tmp |= PCI_EXP_LNKCAP_SLS_8_0GB; > + dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp); > + /* Enable DIRECTED SPEED CHANGE bit of GEN2_CTRL_OFF register */ > + tmp = dw_pcie_readl_dbi(pci, PCIE_PL_GEN2_CTRL_OFF); > + tmp |= PCIE_PL_DIRECTED_SPEED_CHANGE_OFF; > + dw_pcie_writel_dbi(pci, PCIE_PL_GEN2_CTRL_OFF, tmp); > + dw_pcie_dbi_ro_wr_dis(pci); > + > + ret = dw_pcie_wait_for_link(pci); > + if (ret) > + goto err_reset_phy; > + > + /* > + * Reenable DIRECTED SPEED CHANGE. > + * > + * You need to set this bit after each speed change, but after > + * reaching G1, setting it once doesn't seem to work (it reaches G3 > + * equalization states and then times out, falls back to G1). But > + * If after that, you set it again, it then reaches G3 perfectly s/If after/if after/ > + * fine. > + */ > + dw_pcie_dbi_ro_wr_en(pci); > + tmp = dw_pcie_readl_dbi(pci, PCIE_PL_GEN2_CTRL_OFF); > + tmp |= PCIE_PL_DIRECTED_SPEED_CHANGE_OFF; > + dw_pcie_writel_dbi(pci, PCIE_PL_GEN2_CTRL_OFF, tmp); > + dw_pcie_dbi_ro_wr_dis(pci); > + > + ret = dw_pcie_wait_for_link(pci); > + if (ret) > + goto err_reset_phy; > + > + tmp = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); > + dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS); > + return 0; > + > + err_reset_phy: > + dev_err(dev, "Failed to bring link up!\n" > + "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n", > + dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0), > + dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1)); > + return ret; > +} > + > +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 = 0; Unnecessary init of "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) Rewrap text to fill lines. > + */ > + __raw_writel(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 */ > + __raw_writel(0x0, afp->mgmt_base + PCIEX8MGMT_APP_HOLD_PHY_RST); > + /* enable pcieauxclk */ > + ret = clk_prepare_enable(afp->pcie_aux); > + /* set RC mode */ > + __raw_writel(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 const struct dev_pm_ops fu740_pcie_pm_ops = { > + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(fu740_pcie_suspend_noirq, > + fu740_pcie_resume_noirq) fu740_pcie_suspend_noirq() and fu740_pcie_resume_noirq() don't exist. Am I missing something? > +}; > + > +static int fu740_pcie_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct dw_pcie *pci; > + struct fu740_pcie *afp; > + struct resource *mgmt_res; > + struct device_node *node = dev->of_node; > + int ret; > + u16 val; > + > + afp = devm_kzalloc(dev, sizeof(*afp), GFP_KERNEL); > + if (!afp) > + return -ENOMEM; > + > + pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL); > + if (!pci) > + return -ENOMEM; > + > + pci->dev = dev; > + pci->ops = &dw_pcie_ops; > + pci->pp.ops = &fu740_pcie_host_ops; > + > + afp->pci = pci; > + > + mgmt_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mgmt"); Does every driver make up a new name for this register space? I see "mem", "cfg", "app", "dbics", "regs", "config", "ctrl", "dbi", "dbi2", "addr_space", "atu", "cs", "csr", breg", "cfg", "pcireg", etc. I know there *are* different kinds of registers that need different names, but I don't believe there are *this many* different kinds. It'd be nice if different drivers could use the same name for the same registers. > + if (!mgmt_res) { > + dev_warn(dev, "missing required mgmt address range"); > + return -ENOENT; > + } > + afp->mgmt_base = devm_ioremap_resource(dev, mgmt_res); > + if (IS_ERR(afp->mgmt_base)) > + return PTR_ERR(afp->mgmt_base); > + > + /* Fetch GPIOs */ > + afp->perstn_gpio = of_get_named_gpio(node, "perstn-gpios", 0); > + if (gpio_is_valid(afp->perstn_gpio)) { > + ret = devm_gpio_request_one(dev, afp->perstn_gpio, > + GPIOF_OUT_INIT_LOW, "perstn-gpios"); > + if (ret) { > + dev_err(dev, "unable to get perstn gpio\n"); Maybe make the message match the DT property, i.e., "perstn-gpios"? > + return ret; > + } > + } else if (afp->perstn_gpio == -EPROBE_DEFER) { > + dev_err(dev, "perst-gpios EPROBE_DEFER\n"); > + return afp->perstn_gpio; > + } This structure is a little awkward, partly because it makes the implicit assumption that -EPROBE_DEFER is not a valid GPIO number. I think this structure would be better: afp->perstn_gpio = of_get_named_gpio(...); if (afp->perstn_gpio == -EPROBE_DEFER) return perstn_gpio; if (gpio_is_valid(afp->perstn_gpio)) { ret = devm_gpio_request_one(...); if (ret) return ret; } Also, similar code in mvebu_pcie_parse_port() suggests that devm_gpio_request_one() itself can return -EPROBE_DEFER, which seems to be true. I have no idea whether you want to do anything special with -EPROBE_DEFER in that case here. > + afp->pwren_gpio = of_get_named_gpio(node, "pwren-gpios", 0); > + if (gpio_is_valid(afp->pwren_gpio)) { > + ret = devm_gpio_request_one(dev, afp->pwren_gpio, > + GPIOF_OUT_INIT_LOW, "pwren-gpios"); > + if (ret) { > + dev_err(dev, "unable to get pwren gpio\n"); > + return ret; > + } > + } else if (afp->pwren_gpio == -EPROBE_DEFER) { > + dev_err(dev, "pwren-gpios EPROBE_DEFER\n"); > + return afp->pwren_gpio; > + } > + > + /* 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(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; > + > + if (pci_msi_enabled()) { > + u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI); > + > + val = dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS); > + val |= PCI_MSI_FLAGS_ENABLE; > + dw_pcie_writew_dbi(pci, offset + PCI_MSI_FLAGS, val); > + } > + > + 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"}, Typically there are a couple spaces inserted here, i.e., { .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, > + .pm = &fu740_pcie_pm_ops, > + }, Typical indentation would remove a tab before the "}". Match other drivers. > + .probe = fu740_pcie_probe, > + .shutdown = fu740_pcie_shutdown, > +}; > + > +static int __init fu740_pcie_init(void) > +{ > + return platform_driver_register(&fu740_pcie_driver); > +} > + > +device_initcall(fu740_pcie_init); pci-imx6.c is the only other driver that uses device_initcall(). Use builtin_platform_driver() or similar if possible, as other drivers do.
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..6916eea40ea5 --- /dev/null +++ b/drivers/pci/controller/dwc/pcie-fu740.c @@ -0,0 +1,455 @@ +// 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/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/resource.h> +#include <linux/signal.h> +#include <linux/types.h> +#include <linux/interrupt.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; + int perstn_gpio; + int pwren_gpio; + 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 + +/* PCIe Port Logic registers (memory-mapped) */ +#define PL_OFFSET 0x700 +#define PCIE_PL_GEN2_CTRL_OFF (PL_OFFSET + 0x10c) +#define PCIE_PL_DIRECTED_SPEED_CHANGE_OFF 0x20000 + +#define PCIE_PHY_MAX_RETRY_CNT 1000 + +static void fu740_pcie_assert_perstn(struct fu740_pcie *afp) +{ + /* PERST_N GPIO */ + if (gpio_is_valid(afp->perstn_gpio)) + gpio_direction_output(afp->perstn_gpio, 0); + + /* Controller PERST_N */ + __raw_writel(0x0, afp->mgmt_base + PCIEX8MGMT_PERST_N); +} + +static void fu740_pcie_deassert_perstn(struct fu740_pcie *afp) +{ + /* Controller PERST_N */ + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_PERST_N); + /* PERST_N GPIO */ + if (gpio_is_valid(afp->perstn_gpio)) + gpio_direction_output(afp->perstn_gpio, 1); +} + +static void fu740_pcie_power_on(struct fu740_pcie *afp) +{ + if (gpio_is_valid(afp->pwren_gpio)) { + gpio_direction_output(afp->pwren_gpio, 1); + mdelay(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_phyregreadwrite(const uint8_t phy, const uint8_t write, + const uint16_t addr, + const uint16_t wrdata, uint16_t *rddata, + struct fu740_pcie *afp) +{ + unsigned char ack = 0; + unsigned int cnt = 0; + struct device *dev = afp->pci->dev; + + /* setup */ + __raw_writel(addr, + afp->mgmt_base + + (phy ? PCIEX8MGMT_PHY1_CR_PARA_ADDR : + PCIEX8MGMT_PHY0_CR_PARA_ADDR)); + if (write) + __raw_writel(wrdata, + afp->mgmt_base + + (phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_DATA : + PCIEX8MGMT_PHY0_CR_PARA_WR_DATA)); + if (write) + __raw_writel(1, + afp->mgmt_base + + (phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_EN : + PCIEX8MGMT_PHY0_CR_PARA_WR_EN)); + else + __raw_writel(1, + afp->mgmt_base + + (phy ? PCIEX8MGMT_PHY1_CR_PARA_RD_EN : + PCIEX8MGMT_PHY0_CR_PARA_RD_EN)); + + /* wait for wait_idle */ + do { + if (__raw_readl + (afp->mgmt_base + + (phy ? PCIEX8MGMT_PHY1_CR_PARA_ACK : + PCIEX8MGMT_PHY0_CR_PARA_ACK))) { + ack = 1; + if (!write) + __raw_readl(afp->mgmt_base + + (phy ? + PCIEX8MGMT_PHY1_CR_PARA_RD_DATA : + PCIEX8MGMT_PHY0_CR_PARA_RD_DATA)); + } + } while (!ack); + + /* clear */ + if (write) + __raw_writel(0, + afp->mgmt_base + + (phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_EN : + PCIEX8MGMT_PHY0_CR_PARA_WR_EN)); + else + __raw_writel(0, + afp->mgmt_base + + (phy ? PCIEX8MGMT_PHY1_CR_PARA_RD_EN : + PCIEX8MGMT_PHY0_CR_PARA_RD_EN)); + + /* wait for ~wait_idle */ + while (__raw_readl + (afp->mgmt_base + + (phy ? PCIEX8MGMT_PHY1_CR_PARA_ACK : + PCIEX8MGMT_PHY0_CR_PARA_ACK))) { + cpu_relax(); + cnt++; + if (cnt > PCIE_PHY_MAX_RETRY_CNT) { + dev_err(dev, "PCIE phy doesn't enter idle state.\n"); + break; + } + } +} + +static void fu740_pcie_init_phy(struct fu740_pcie *afp) +{ + int lane; + + /* enable phy cr_para_sel interfaces */ + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_PHY0_CR_PARA_SEL); + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_PHY1_CR_PARA_SEL); + + /* wait 10 cr_para cycles */ + msleep(1); + + /* set PHY AC termination mode */ + for (lane = 0; lane < 4; lane++) { + fu740_phyregreadwrite(0, 1, + 0x1008 + (0x100 * lane), + 0x0e21, NULL, afp); + fu740_phyregreadwrite(1, 1, + 0x1008 + (0x100 * lane), + 0x0e21, NULL, afp); + } + +} + +static void fu740_pcie_ltssm_enable(struct device *dev) +{ + struct fu740_pcie *afp = dev_get_drvdata(dev); + + /* Enable LTSSM */ + __raw_writel(0x1, afp->mgmt_base + PCIEX8MGMT_APP_LTSSM_ENABLE); +} + +static int fu740_pcie_start_link(struct dw_pcie *pci) +{ + struct device *dev = pci->dev; + u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + u32 tmp; + int ret; + + /* + * Force Gen1 operation when starting the link. In case the link is + * started in Gen2 mode, there is a possibility the devices on the + * bus will not be detected at all. This happens with PCIe switches. + */ + dw_pcie_dbi_ro_wr_en(pci); + tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); + tmp &= ~PCI_EXP_LNKCAP_SLS; + tmp |= PCI_EXP_LNKCAP_SLS_2_5GB; + dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp); + dw_pcie_dbi_ro_wr_dis(pci); + + /* Start LTSSM. */ + fu740_pcie_ltssm_enable(dev); + + ret = dw_pcie_wait_for_link(pci); + if (ret) + goto err_reset_phy; + + /* Now set it to operate in Gen3 */ + dw_pcie_dbi_ro_wr_en(pci); + tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); + tmp &= ~PCI_EXP_LNKCAP_SLS; + tmp |= PCI_EXP_LNKCAP_SLS_8_0GB; + dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp); + /* Enable DIRECTED SPEED CHANGE bit of GEN2_CTRL_OFF register */ + tmp = dw_pcie_readl_dbi(pci, PCIE_PL_GEN2_CTRL_OFF); + tmp |= PCIE_PL_DIRECTED_SPEED_CHANGE_OFF; + dw_pcie_writel_dbi(pci, PCIE_PL_GEN2_CTRL_OFF, tmp); + dw_pcie_dbi_ro_wr_dis(pci); + + ret = dw_pcie_wait_for_link(pci); + if (ret) + goto err_reset_phy; + + /* + * Reenable DIRECTED SPEED CHANGE. + * + * You need to set this bit after each speed change, but after + * reaching G1, setting it once doesn't seem to work (it reaches G3 + * equalization states and then times out, falls back to G1). But + * If after that, you set it again, it then reaches G3 perfectly + * fine. + */ + dw_pcie_dbi_ro_wr_en(pci); + tmp = dw_pcie_readl_dbi(pci, PCIE_PL_GEN2_CTRL_OFF); + tmp |= PCIE_PL_DIRECTED_SPEED_CHANGE_OFF; + dw_pcie_writel_dbi(pci, PCIE_PL_GEN2_CTRL_OFF, tmp); + dw_pcie_dbi_ro_wr_dis(pci); + + ret = dw_pcie_wait_for_link(pci); + if (ret) + goto err_reset_phy; + + tmp = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); + dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS); + return 0; + + err_reset_phy: + dev_err(dev, "Failed to bring link up!\n" + "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n", + dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0), + dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1)); + return ret; +} + +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 = 0; + + /* 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) + */ + __raw_writel(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 */ + __raw_writel(0x0, afp->mgmt_base + PCIEX8MGMT_APP_HOLD_PHY_RST); + /* enable pcieauxclk */ + ret = clk_prepare_enable(afp->pcie_aux); + /* set RC mode */ + __raw_writel(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 const struct dev_pm_ops fu740_pcie_pm_ops = { + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(fu740_pcie_suspend_noirq, + fu740_pcie_resume_noirq) +}; + +static int fu740_pcie_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct dw_pcie *pci; + struct fu740_pcie *afp; + struct resource *mgmt_res; + struct device_node *node = dev->of_node; + int ret; + u16 val; + + afp = devm_kzalloc(dev, sizeof(*afp), GFP_KERNEL); + if (!afp) + return -ENOMEM; + + pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL); + if (!pci) + return -ENOMEM; + + pci->dev = dev; + pci->ops = &dw_pcie_ops; + pci->pp.ops = &fu740_pcie_host_ops; + + afp->pci = pci; + + mgmt_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mgmt"); + if (!mgmt_res) { + dev_warn(dev, "missing required mgmt address range"); + return -ENOENT; + } + afp->mgmt_base = devm_ioremap_resource(dev, mgmt_res); + if (IS_ERR(afp->mgmt_base)) + return PTR_ERR(afp->mgmt_base); + + /* Fetch GPIOs */ + afp->perstn_gpio = of_get_named_gpio(node, "perstn-gpios", 0); + if (gpio_is_valid(afp->perstn_gpio)) { + ret = devm_gpio_request_one(dev, afp->perstn_gpio, + GPIOF_OUT_INIT_LOW, "perstn-gpios"); + if (ret) { + dev_err(dev, "unable to get perstn gpio\n"); + return ret; + } + } else if (afp->perstn_gpio == -EPROBE_DEFER) { + dev_err(dev, "perst-gpios EPROBE_DEFER\n"); + return afp->perstn_gpio; + } + + afp->pwren_gpio = of_get_named_gpio(node, "pwren-gpios", 0); + if (gpio_is_valid(afp->pwren_gpio)) { + ret = devm_gpio_request_one(dev, afp->pwren_gpio, + GPIOF_OUT_INIT_LOW, "pwren-gpios"); + if (ret) { + dev_err(dev, "unable to get pwren gpio\n"); + return ret; + } + } else if (afp->pwren_gpio == -EPROBE_DEFER) { + dev_err(dev, "pwren-gpios EPROBE_DEFER\n"); + return afp->pwren_gpio; + } + + /* 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(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; + + if (pci_msi_enabled()) { + u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI); + + val = dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS); + val |= PCI_MSI_FLAGS_ENABLE; + dw_pcie_writew_dbi(pci, offset + PCI_MSI_FLAGS, val); + } + + 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, + .pm = &fu740_pcie_pm_ops, + }, + .probe = fu740_pcie_probe, + .shutdown = fu740_pcie_shutdown, +}; + +static int __init fu740_pcie_init(void) +{ + return platform_driver_register(&fu740_pcie_driver); +} + +device_initcall(fu740_pcie_init);