[PATCH] PCI: zynqmp: Add ZynqMP NWL PCIe root port driver
Pali Rohár
pali at kernel.org
Tue May 23 19:17:23 CEST 2023
Hello! I have looked at this change and below are my comments.
On Tuesday 23 May 2023 14:57:38 Stefan Roese wrote:
> This patch adds the PCIe controller driver for the Xilinx / AMD ZynqMP
> NWL PCIe Bridge as root port. The driver source is partly copied from
> the Linux PCI driver and modified to enable usage in U-Boot (e.g.
> simplified and interrupt support removed).
>
> Signed-off-by: Stefan Roese <sr at denx.de>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Pali Rohár <pali at kernel.org>
> Cc: Bin Meng <bmeng.cn at gmail.com>
> Cc: Michal Simek <michal.simek at amd.com>
> ---
> MAINTAINERS | 1 +
> drivers/pci/Kconfig | 7 +
> drivers/pci/Makefile | 1 +
> drivers/pci/pcie-xilinx-nwl.c | 374 ++++++++++++++++++++++++++++++++++
> 4 files changed, 383 insertions(+)
> create mode 100644 drivers/pci/pcie-xilinx-nwl.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index c8f72e9ec6a2..2bc19d9daa75 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -343,6 +343,7 @@ F: drivers/rtc/armada38x.c
> F: drivers/spi/kirkwood_spi.c
> F: drivers/spi/mvebu_a3700_spi.c
> F: drivers/pci/pcie_dw_mvebu.c
> +F: drivers/pci/pcie-xilinx-nwl.c
> F: drivers/watchdog/armada-37xx-wdt.c
> F: drivers/watchdog/orion_wdt.c
> F: include/configs/mv-common.h
> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> index ef328d26525b..60d98d14640d 100644
> --- a/drivers/pci/Kconfig
> +++ b/drivers/pci/Kconfig
> @@ -374,4 +374,11 @@ config PCIE_UNIPHIER
> Say Y here if you want to enable PCIe controller support on
> UniPhier SoCs.
>
> +config PCIE_XILINX_NWL
> + bool "Xilinx NWL PCIe controller"
> + depends on ARCH_ZYNQMP
> + help
> + Say 'Y' here if you want support for Xilinx / AMD NWL PCIe
> + controller as Root Port.
> +
> endif
> diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
> index 49506e7ba59b..11f60c6991d9 100644
> --- a/drivers/pci/Makefile
> +++ b/drivers/pci/Makefile
> @@ -49,3 +49,4 @@ obj-$(CONFIG_PCI_OCTEONTX) += pci_octeontx.o
> obj-$(CONFIG_PCIE_OCTEON) += pcie_octeon.o
> obj-$(CONFIG_PCIE_DW_SIFIVE) += pcie_dw_sifive.o
> obj-$(CONFIG_PCIE_UNIPHIER) += pcie_uniphier.o
> +obj-$(CONFIG_PCIE_XILINX_NWL) += pcie-xilinx-nwl.o
> diff --git a/drivers/pci/pcie-xilinx-nwl.c b/drivers/pci/pcie-xilinx-nwl.c
> new file mode 100644
> index 000000000000..3d64a0e3b961
> --- /dev/null
> +++ b/drivers/pci/pcie-xilinx-nwl.c
> @@ -0,0 +1,374 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * PCIe host bridge driver for Xilinx / AMD ZynqMP NWL PCIe Bridge
> + *
> + * Based on the Linux driver which is:
> + * (C) Copyright 2014 - 2015, Xilinx, Inc.
> + *
> + * Author: Stefan Roese <sr at denx.de>
> + */
> +
> +#include <clk.h>
> +#include <dm.h>
> +#include <dm/device_compat.h>
> +#include <dm/devres.h>
> +#include <mapmem.h>
> +#include <pci.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +
> +/* Bridge core config registers */
> +#define BRCFG_PCIE_RX0 0x00000000
> +#define BRCFG_PCIE_RX1 0x00000004
> +#define BRCFG_INTERRUPT 0x00000010
> +#define BRCFG_PCIE_RX_MSG_FILTER 0x00000020
> +
> +/* Egress - Bridge translation registers */
> +#define E_BREG_CAPABILITIES 0x00000200
> +#define E_BREG_CONTROL 0x00000208
> +#define E_BREG_BASE_LO 0x00000210
> +#define E_BREG_BASE_HI 0x00000214
> +#define E_ECAM_CAPABILITIES 0x00000220
> +#define E_ECAM_CONTROL 0x00000228
> +#define E_ECAM_BASE_LO 0x00000230
> +#define E_ECAM_BASE_HI 0x00000234
> +
> +#define I_ISUB_CONTROL 0x000003E8
> +#define SET_ISUB_CONTROL BIT(0)
> +/* Rxed msg fifo - Interrupt status registers */
> +#define MSGF_MISC_STATUS 0x00000400
> +#define MSGF_MISC_MASK 0x00000404
> +#define MSGF_LEG_STATUS 0x00000420
> +#define MSGF_LEG_MASK 0x00000424
> +#define MSGF_MSI_STATUS_LO 0x00000440
> +#define MSGF_MSI_STATUS_HI 0x00000444
> +#define MSGF_MSI_MASK_LO 0x00000448
> +#define MSGF_MSI_MASK_HI 0x0000044C
> +
> +/* Msg filter mask bits */
> +#define CFG_ENABLE_PM_MSG_FWD BIT(1)
> +#define CFG_ENABLE_INT_MSG_FWD BIT(2)
> +#define CFG_ENABLE_ERR_MSG_FWD BIT(3)
> +#define CFG_ENABLE_MSG_FILTER_MASK (CFG_ENABLE_PM_MSG_FWD | \
> + CFG_ENABLE_INT_MSG_FWD | \
> + CFG_ENABLE_ERR_MSG_FWD)
> +
> +/* Misc interrupt status mask bits */
> +#define MSGF_MISC_SR_RXMSG_AVAIL BIT(0)
> +#define MSGF_MISC_SR_RXMSG_OVER BIT(1)
> +#define MSGF_MISC_SR_SLAVE_ERR BIT(4)
> +#define MSGF_MISC_SR_MASTER_ERR BIT(5)
> +#define MSGF_MISC_SR_I_ADDR_ERR BIT(6)
> +#define MSGF_MISC_SR_E_ADDR_ERR BIT(7)
> +#define MSGF_MISC_SR_FATAL_AER BIT(16)
> +#define MSGF_MISC_SR_NON_FATAL_AER BIT(17)
> +#define MSGF_MISC_SR_CORR_AER BIT(18)
> +#define MSGF_MISC_SR_UR_DETECT BIT(20)
> +#define MSGF_MISC_SR_NON_FATAL_DEV BIT(22)
> +#define MSGF_MISC_SR_FATAL_DEV BIT(23)
> +#define MSGF_MISC_SR_LINK_DOWN BIT(24)
> +#define MSGF_MSIC_SR_LINK_AUTO_BWIDTH BIT(25)
> +#define MSGF_MSIC_SR_LINK_BWIDTH BIT(26)
> +
> +#define MSGF_MISC_SR_MASKALL (MSGF_MISC_SR_RXMSG_AVAIL | \
> + MSGF_MISC_SR_RXMSG_OVER | \
> + MSGF_MISC_SR_SLAVE_ERR | \
> + MSGF_MISC_SR_MASTER_ERR | \
> + MSGF_MISC_SR_I_ADDR_ERR | \
> + MSGF_MISC_SR_E_ADDR_ERR | \
> + MSGF_MISC_SR_FATAL_AER | \
> + MSGF_MISC_SR_NON_FATAL_AER | \
> + MSGF_MISC_SR_CORR_AER | \
> + MSGF_MISC_SR_UR_DETECT | \
> + MSGF_MISC_SR_NON_FATAL_DEV | \
> + MSGF_MISC_SR_FATAL_DEV | \
> + MSGF_MISC_SR_LINK_DOWN | \
> + MSGF_MSIC_SR_LINK_AUTO_BWIDTH | \
> + MSGF_MSIC_SR_LINK_BWIDTH)
> +
> +/* Legacy interrupt status mask bits */
> +#define MSGF_LEG_SR_INTA BIT(0)
> +#define MSGF_LEG_SR_INTB BIT(1)
> +#define MSGF_LEG_SR_INTC BIT(2)
> +#define MSGF_LEG_SR_INTD BIT(3)
> +#define MSGF_LEG_SR_MASKALL (MSGF_LEG_SR_INTA | MSGF_LEG_SR_INTB | \
> + MSGF_LEG_SR_INTC | MSGF_LEG_SR_INTD)
> +
> +/* MSI interrupt status mask bits */
> +#define MSGF_MSI_SR_LO_MASK GENMASK(31, 0)
> +#define MSGF_MSI_SR_HI_MASK GENMASK(31, 0)
> +
> +/* Bridge config interrupt mask */
> +#define BRCFG_INTERRUPT_MASK BIT(0)
> +#define BREG_PRESENT BIT(0)
> +#define BREG_ENABLE BIT(0)
> +#define BREG_ENABLE_FORCE BIT(1)
> +
> +/* E_ECAM status mask bits */
> +#define E_ECAM_PRESENT BIT(0)
> +#define E_ECAM_CR_ENABLE BIT(0)
> +#define E_ECAM_SIZE_LOC GENMASK(20, 16)
> +#define E_ECAM_SIZE_SHIFT 16
> +#define NWL_ECAM_VALUE_DEFAULT 12
> +
> +#define CFG_DMA_REG_BAR GENMASK(2, 0)
> +#define CFG_PCIE_CACHE GENMASK(7, 0)
> +
> +/* Readin the PS_LINKUP */
> +#define PS_LINKUP_OFFSET 0x00000238
> +#define PCIE_PHY_LINKUP_BIT BIT(0)
> +#define PHY_RDY_LINKUP_BIT BIT(1)
> +
> +/* Parameters for the waiting for link up routine */
> +#define LINK_WAIT_MAX_RETRIES 10
> +#define LINK_WAIT_USLEEP_MIN 90000
> +#define LINK_WAIT_USLEEP_MAX 100000
> +
> +struct nwl_pcie {
> + struct udevice *dev;
> + void __iomem *breg_base;
> + void __iomem *pcireg_base;
> + void __iomem *ecam_base;
> + phys_addr_t phys_breg_base; /* Physical Bridge Register Base */
> + phys_addr_t phys_pcie_reg_base; /* Physical PCIe Controller Base */
Unused member
> + phys_addr_t phys_ecam_base; /* Physical Configuration Base */
> + u32 breg_size;
Unused member
> + u32 pcie_reg_size;
Unused member
> + u32 ecam_size;
Unused member
> + u32 ecam_value;
> + u8 last_busno;
Unused member
> +};
> +
> +static int nwl_pcie_config_address(const struct udevice *bus,
> + pci_dev_t bdf, uint offset,
> + void **paddress)
> +{
> + struct nwl_pcie *pcie = dev_get_priv(bus);
> + void *addr;
> +
> + addr = pcie->ecam_base;
> + addr += PCIE_ECAM_OFFSET(PCI_BUS(bdf), PCI_DEV(bdf),
> + PCI_FUNC(bdf), offset);
As pci bus number you should use: PCI_BUS(bdf)-dev_seq(bus)
This is because U-Boot PCI bus numbers are relative to the bus number on
which U-Boot puts PCIe Root Port; and because U-Boot does that bus
remapping. Normally first controller has dev seq 0, so this issue is not
visible on system without multiple PCIe controllers. I guess this is
here in U-Boot because U-Boot does not have PCI domains.
> + *paddress = addr;
> +
> + return 0;
> +}
> +
> +static int nwl_pcie_read_config(const struct udevice *bus, pci_dev_t bdf,
> + uint offset, ulong *valuep,
> + enum pci_size_t size)
> +{
> + return pci_generic_mmap_read_config(bus, nwl_pcie_config_address,
> + bdf, offset, valuep, size);
> +}
> +
> +static int nwl_pcie_write_config(struct udevice *bus, pci_dev_t bdf,
> + uint offset, ulong value,
> + enum pci_size_t size)
> +{
> + return pci_generic_mmap_write_config(bus, nwl_pcie_config_address,
> + bdf, offset, value, size);
> +}
> +
> +static const struct dm_pci_ops nwl_pcie_ops = {
> + .read_config = nwl_pcie_read_config,
> + .write_config = nwl_pcie_write_config,
> +};
> +
> +static inline u32 nwl_bridge_readl(struct nwl_pcie *pcie, u32 off)
> +{
> + return readl(pcie->breg_base + off);
> +}
> +
> +static inline void nwl_bridge_writel(struct nwl_pcie *pcie, u32 val, u32 off)
> +{
> + writel(val, pcie->breg_base + off);
> +}
> +
> +static bool nwl_pcie_link_up(struct nwl_pcie *pcie)
> +{
> + if (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) & PCIE_PHY_LINKUP_BIT)
> + return true;
> + return false;
> +}
> +
> +static bool nwl_phy_link_up(struct nwl_pcie *pcie)
> +{
> + if (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) & PHY_RDY_LINKUP_BIT)
> + return true;
> + return false;
> +}
> +
> +static int nwl_wait_for_link(struct nwl_pcie *pcie)
> +{
> + struct udevice *dev = pcie->dev;
> + int retries;
> +
> + /* check if the link is up or not */
> + for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
> + if (nwl_phy_link_up(pcie))
> + return 0;
> + udelay(LINK_WAIT_USLEEP_MIN);
> + }
> +
> + dev_warn(dev, "PHY link never came up\n");
> + return -ETIMEDOUT;
> +}
> +
> +static int nwl_pcie_bridge_init(struct nwl_pcie *pcie)
> +{
> + struct udevice *dev = pcie->dev;
> + u32 breg_val, ecam_val, first_busno = 0;
> + int err;
> +
> + breg_val = nwl_bridge_readl(pcie, E_BREG_CAPABILITIES) & BREG_PRESENT;
> + if (!breg_val) {
> + dev_err(dev, "BREG is not present\n");
> + return breg_val;
> + }
> +
> + /* Write bridge_off to breg base */
> + nwl_bridge_writel(pcie, lower_32_bits(pcie->phys_breg_base),
> + E_BREG_BASE_LO);
> + nwl_bridge_writel(pcie, upper_32_bits(pcie->phys_breg_base),
> + E_BREG_BASE_HI);
> +
> + /* Enable BREG */
> + nwl_bridge_writel(pcie, ~BREG_ENABLE_FORCE & BREG_ENABLE,
> + E_BREG_CONTROL);
> +
> + /* Disable DMA channel registers */
> + nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_PCIE_RX0) |
> + CFG_DMA_REG_BAR, BRCFG_PCIE_RX0);
> +
> + /* Enable Ingress subtractive decode translation */
> + nwl_bridge_writel(pcie, SET_ISUB_CONTROL, I_ISUB_CONTROL);
> +
> + /* Enable msg filtering details */
> + nwl_bridge_writel(pcie, CFG_ENABLE_MSG_FILTER_MASK,
> + BRCFG_PCIE_RX_MSG_FILTER);
> +
> + err = nwl_wait_for_link(pcie);
> + if (err)
> + return err;
> +
> + ecam_val = nwl_bridge_readl(pcie, E_ECAM_CAPABILITIES) & E_ECAM_PRESENT;
> + if (!ecam_val) {
> + dev_err(dev, "ECAM is not present\n");
> + return ecam_val;
> + }
> +
> + /* Enable ECAM */
> + nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
> + E_ECAM_CR_ENABLE, E_ECAM_CONTROL);
> +
> + nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
> + (pcie->ecam_value << E_ECAM_SIZE_SHIFT),
> + E_ECAM_CONTROL);
> +
> + nwl_bridge_writel(pcie, lower_32_bits(pcie->phys_ecam_base),
> + E_ECAM_BASE_LO);
> + nwl_bridge_writel(pcie, upper_32_bits(pcie->phys_ecam_base),
> + E_ECAM_BASE_HI);
> +
> + /* Get bus range */
> + ecam_val = nwl_bridge_readl(pcie, E_ECAM_CONTROL);
> + pcie->last_busno = (ecam_val & E_ECAM_SIZE_LOC) >> E_ECAM_SIZE_SHIFT;
> + /* Write primary, secondary and subordinate bus numbers */
> + ecam_val = first_busno;
> + ecam_val |= (first_busno + 1) << 8;
> + ecam_val |= (pcie->last_busno << E_ECAM_SIZE_SHIFT);
> + writel(ecam_val, (pcie->ecam_base + PCI_PRIMARY_BUS));
This writel() overwrites standard PCI Bridge registers at BDF 0:0.0,
which should be PCIe Root Port. This should be really not needed for
U-Boot (and neither for Linux kernel) because pci autoconf code
correctly discover and configures all PCI Bridge devices.
If there is not bug in U-Boot pci code then this register is overwritten
by U-Boot at later phase and therefore any change done here is lost.
Anyway, more readable expression for writing to BDF 0:0.0 at
PCI_PRIMARY_BUS register could be:
writel(ecam_val, pcie->ecam_base + PCIE_ECAM_OFFSET(0, 0, 0, PCI_PRIMARY_BUS));
> +
> + if (nwl_pcie_link_up(pcie))
> + dev_info(dev, "Link is UP\n");
> + else
> + dev_info(dev, "Link is DOWN\n");
> +
> + /* Disable all misc interrupts */
> + nwl_bridge_writel(pcie, (u32)~MSGF_MISC_SR_MASKALL, MSGF_MISC_MASK);
> +
> + /* Clear pending misc interrupts */
> + nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_MISC_STATUS) &
> + MSGF_MISC_SR_MASKALL, MSGF_MISC_STATUS);
> +
> + /* Disable all legacy interrupts */
> + nwl_bridge_writel(pcie, (u32)~MSGF_LEG_SR_MASKALL, MSGF_LEG_MASK);
> +
> + /* Clear pending legacy interrupts */
> + nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_LEG_STATUS) &
> + MSGF_LEG_SR_MASKALL, MSGF_LEG_STATUS);
> +
> + return 0;
> +}
> +
> +static int nwl_pcie_parse_dt(struct nwl_pcie *pcie)
> +{
> + struct udevice *dev = pcie->dev;
> + struct resource res;
> + int ret;
> +
> + ret = dev_read_resource_byname(dev, "breg", &res);
> + if (ret)
> + return ret;
> + pcie->breg_base = devm_ioremap(dev, res.start, resource_size(&res));
> + if (IS_ERR(pcie->breg_base))
> + return PTR_ERR(pcie->breg_base);
> + pcie->phys_breg_base = res.start;
> +
> + ret = dev_read_resource_byname(dev, "pcireg", &res);
> + if (ret)
> + return ret;
> + pcie->pcireg_base = devm_ioremap(dev, res.start, resource_size(&res));
> + if (IS_ERR(pcie->pcireg_base))
> + return PTR_ERR(pcie->pcireg_base);
> + pcie->phys_pcie_reg_base = res.start;
> +
> + ret = dev_read_resource_byname(dev, "cfg", &res);
> + if (ret)
> + return ret;
> + pcie->ecam_base = devm_ioremap(dev, res.start, resource_size(&res));
> + if (IS_ERR(pcie->ecam_base))
> + return PTR_ERR(pcie->ecam_base);
> + pcie->phys_ecam_base = res.start;
> +
> + return 0;
> +}
> +
> +static int nwl_pcie_probe(struct udevice *dev)
> +{
> + struct nwl_pcie *pcie = dev_get_priv(dev);
> + int err;
> +
> + pcie->dev = dev;
> + pcie->ecam_value = NWL_ECAM_VALUE_DEFAULT;
> +
> + err = nwl_pcie_parse_dt(pcie);
> + if (err) {
> + dev_err(dev, "Parsing DT failed\n");
> + return err;
> + }
> +
> + err = nwl_pcie_bridge_init(pcie);
> + if (err) {
> + dev_err(dev, "HW Initialization failed\n");
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static const struct udevice_id nwl_pcie_of_match[] = {
> + { .compatible = "xlnx,nwl-pcie-2.11", },
> + { /* sentinel */ }
> +};
> +
> +U_BOOT_DRIVER(nwl_pcie) = {
> + .name = "nwl-pcie",
> + .id = UCLASS_PCI,
> + .of_match = nwl_pcie_of_match,
> + .probe = nwl_pcie_probe,
> + .priv_auto = sizeof(struct nwl_pcie),
> + .ops = &nwl_pcie_ops,
> +};
> --
> 2.40.1
>
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