Hi Herve,
On Tue Apr 30, 2024 at 10:37 AM CEST, Herve Codina wrote:
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>
> Add a PCI driver that handles the LAN966x PCI device using a device-tree
> overlay. This overlay is applied to the PCI device DT node and allows to
> describe components that are present in the device.
>
> The memory from the device-tree is remapped to the BAR memory thanks to
> "ranges" properties computed at runtime by the PCI core during the PCI
> enumeration.
> The PCI device itself acts as an interrupt controller and is used as the
> parent of the internal LAN966x interrupt controller to route the
> interrupts to the assigned PCI INTx interrupt.
>
> Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
> ---
> drivers/mfd/Kconfig | 24 ++++
> drivers/mfd/Makefile | 4 +
> drivers/mfd/lan966x_pci.c | 229 +++++++++++++++++++++++++++++++++++
> drivers/mfd/lan966x_pci.dtso | 167 +++++++++++++++++++++++++
> drivers/pci/quirks.c | 1 +
> 5 files changed, 425 insertions(+)
> create mode 100644 drivers/mfd/lan966x_pci.c
> create mode 100644 drivers/mfd/lan966x_pci.dtso
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 4b023ee229cf..e5f5d2986dd3 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -144,6 +144,30 @@ config MFD_ATMEL_FLEXCOM
> by the probe function of this MFD driver according to a device tree
> property.
>
> +config MFD_LAN966X_PCI
> + tristate "Microchip LAN966x PCIe Support"
> + depends on PCI
> + select OF
> + select OF_OVERLAY
> + select IRQ_DOMAIN
> + help
> + This enables the support for the LAN966x PCIe device.
> + This is used to drive the LAN966x PCIe device from the host system
> + to which it is connected.
> +
> + This driver uses an overlay to load other drivers to support for
> + LAN966x internal components.
> + Even if this driver does not depend on these other drivers, in order
> + to have a fully functional board, the following drivers are needed:
> + - fixed-clock (COMMON_CLK)
> + - lan966x-oic (LAN966X_OIC)
> + - lan966x-cpu-syscon (MFD_SYSCON)
> + - lan966x-switch-reset (RESET_MCHP_SPARX5)
> + - lan966x-pinctrl (PINCTRL_OCELOT)
> + - lan966x-serdes (PHY_LAN966X_SERDES)
> + - lan966x-miim (MDIO_MSCC_MIIM)
> + - lan966x-switch (LAN966X_SWITCH)
> +
> config MFD_ATMEL_HLCDC
> tristate "Atmel HLCDC (High-end LCD Controller)"
> select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index c66f07edcd0e..165a9674ff48 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -284,3 +284,7 @@ rsmu-i2c-objs := rsmu_core.o rsmu_i2c.o
> rsmu-spi-objs := rsmu_core.o rsmu_spi.o
> obj-$(CONFIG_MFD_RSMU_I2C) += rsmu-i2c.o
> obj-$(CONFIG_MFD_RSMU_SPI) += rsmu-spi.o
> +
> +lan966x-pci-objs := lan966x_pci.o
> +lan966x-pci-objs += lan966x_pci.dtbo.o
> +obj-$(CONFIG_MFD_LAN966X_PCI) += lan966x-pci.o
> diff --git a/drivers/mfd/lan966x_pci.c b/drivers/mfd/lan966x_pci.c
> new file mode 100644
> index 000000000000..d9d886a1948f
> --- /dev/null
> +++ b/drivers/mfd/lan966x_pci.c
> @@ -0,0 +1,229 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Microchip LAN966x PCI driver
> + *
> + * Copyright (c) 2024 Microchip Technology Inc. and its subsidiaries.
> + *
> + * Authors:
> + * Clément Léger <clement.leger@xxxxxxxxxxx>
> + * Hervé Codina <herve.codina@xxxxxxxxxxx>
> + */
> +
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/pci.h>
> +#include <linux/slab.h>
> +
> +/* Embedded dtbo symbols created by cmd_wrap_S_dtb in scripts/Makefile.lib */
> +extern char __dtbo_lan966x_pci_begin[];
> +extern char __dtbo_lan966x_pci_end[];
> +
> +struct pci_dev_intr_ctrl {
> + struct pci_dev *pci_dev;
> + struct irq_domain *irq_domain;
> + int irq;
> +};
> +
> +static int pci_dev_irq_domain_map(struct irq_domain *d, unsigned int virq, irq_hw_number_t hw)
> +{
> + irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
> + return 0;
> +}
> +
> +static const struct irq_domain_ops pci_dev_irq_domain_ops = {
> + .map = pci_dev_irq_domain_map,
> + .xlate = irq_domain_xlate_onecell,
> +};
> +
> +static irqreturn_t pci_dev_irq_handler(int irq, void *data)
> +{
> + struct pci_dev_intr_ctrl *intr_ctrl = data;
> + int ret;
> +
> + ret = generic_handle_domain_irq(intr_ctrl->irq_domain, 0);
> + return ret ? IRQ_NONE : IRQ_HANDLED;
> +}
> +
> +static struct pci_dev_intr_ctrl *pci_dev_create_intr_ctrl(struct pci_dev *pdev)
> +{
> + struct pci_dev_intr_ctrl *intr_ctrl;
> + struct fwnode_handle *fwnode;
> + int ret;
> +
> + if (!pdev->irq)
> + return ERR_PTR(-EOPNOTSUPP);
> +
> + fwnode = dev_fwnode(&pdev->dev);
> + if (!fwnode)
> + return ERR_PTR(-ENODEV);
> +
> + intr_ctrl = kmalloc(sizeof(*intr_ctrl), GFP_KERNEL);
> + if (!intr_ctrl)
> + return ERR_PTR(-ENOMEM);
> +
> + intr_ctrl->pci_dev = pdev;
> +
> + intr_ctrl->irq_domain = irq_domain_create_linear(fwnode, 1, &pci_dev_irq_domain_ops,
> + intr_ctrl);
> + if (!intr_ctrl->irq_domain) {
> + pci_err(pdev, "Failed to create irqdomain\n");
> + ret = -ENOMEM;
> + goto err_free_intr_ctrl;
> + }
> +
> + ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_LEGACY);
> + if (ret < 0) {
> + pci_err(pdev, "Unable alloc irq vector (%d)\n", ret);
> + goto err_remove_domain;
> + }
> + intr_ctrl->irq = pci_irq_vector(pdev, 0);
> + ret = request_irq(intr_ctrl->irq, pci_dev_irq_handler, IRQF_SHARED,
> + dev_name(&pdev->dev), intr_ctrl);
> + if (ret) {
> + pci_err(pdev, "Unable to request irq %d (%d)\n", intr_ctrl->irq, ret);
> + goto err_free_irq_vector;
> + }
> +
> + return intr_ctrl;
> +
> +err_free_irq_vector:
> + pci_free_irq_vectors(pdev);
> +err_remove_domain:
> + irq_domain_remove(intr_ctrl->irq_domain);
> +err_free_intr_ctrl:
> + kfree(intr_ctrl);
> + return ERR_PTR(ret);
> +}
> +
> +static void pci_dev_remove_intr_ctrl(struct pci_dev_intr_ctrl *intr_ctrl)
> +{
> + free_irq(intr_ctrl->irq, intr_ctrl);
> + pci_free_irq_vectors(intr_ctrl->pci_dev);
> + irq_dispose_mapping(irq_find_mapping(intr_ctrl->irq_domain, 0));
> + irq_domain_remove(intr_ctrl->irq_domain);
> + kfree(intr_ctrl);
> +}
> +
It looks like the two functions below (and their helper functions) are so
generic that they could be part of the pci driver core support.
Any plans for that?
> +static void devm_pci_dev_remove_intr_ctrl(void *data)
> +{
> + struct pci_dev_intr_ctrl *intr_ctrl = data;
> +
> + pci_dev_remove_intr_ctrl(intr_ctrl);
> +}
> +
> +static int devm_pci_dev_create_intr_ctrl(struct pci_dev *pdev)
> +{
> + struct pci_dev_intr_ctrl *intr_ctrl;
> +
> + intr_ctrl = pci_dev_create_intr_ctrl(pdev);
> +
> + if (IS_ERR(intr_ctrl))
> + return PTR_ERR(intr_ctrl);
> +
> + return devm_add_action_or_reset(&pdev->dev, devm_pci_dev_remove_intr_ctrl, intr_ctrl);
> +}
> +
...
[snip]
...
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index eff7f5df08e2..9933f245b781 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -6241,6 +6241,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0xa76e, dpc_log_size);
> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_XILINX, 0x5020, of_pci_make_dev_node);
> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_XILINX, 0x5021, of_pci_make_dev_node);
> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_REDHAT, 0x0005, of_pci_make_dev_node);
> +DECLARE_PCI_FIXUP_FINAL(0x1055, 0x9660, of_pci_make_dev_node);
>
> /*
> * Devices known to require a longer delay before first config space access
> --
> 2.44.0
Best Regards
Steen
