On Thu, Aug 28, 2025 at 10:17:40AM GMT, Chen Wang wrote:
> From: Chen Wang <unicorn_wang@xxxxxxxxxxx>
>
> Add support for PCIe controller in SG2042 SoC. The controller
> uses the Cadence PCIe core programmed by pcie-cadence*.c. The
> PCIe controller will work in host mode only.
>
Supported data rate, lanes etc...
> Signed-off-by: Chen Wang <unicorn_wang@xxxxxxxxxxx>
> ---
> drivers/pci/controller/cadence/Kconfig | 12 ++
> drivers/pci/controller/cadence/Makefile | 1 +
> drivers/pci/controller/cadence/pcie-sg2042.c | 134 +++++++++++++++++++
> 3 files changed, 147 insertions(+)
> create mode 100644 drivers/pci/controller/cadence/pcie-sg2042.c
>
> diff --git a/drivers/pci/controller/cadence/Kconfig b/drivers/pci/controller/cadence/Kconfig
> index 666e16b6367f..b1f1941d5208 100644
> --- a/drivers/pci/controller/cadence/Kconfig
> +++ b/drivers/pci/controller/cadence/Kconfig
> @@ -42,6 +42,17 @@ config PCIE_CADENCE_PLAT_EP
> endpoint mode. This PCIe controller may be embedded into many
> different vendors SoCs.
>
> +config PCIE_SG2042
PCIE_SG2042_HOST
> + bool "Sophgo SG2042 PCIe controller (host mode)"
Since this driver doesn't implement irqchip, you should make it tristate and as
a module.
> + depends on ARCH_SOPHGO || COMPILE_TEST
> + depends on OF
depends on OF && (ARCH_SOPHGO || COMPILE_TEST)
> + depends on PCI_MSI
> + select PCIE_CADENCE_HOST
> + help
> + Say Y here if you want to support the Sophgo SG2042 PCIe platform
> + controller in host mode. Sophgo SG2042 PCIe controller uses Cadence
> + PCIe core.
> +
> config PCI_J721E
> tristate
> select PCIE_CADENCE_HOST if PCI_J721E_HOST != n
> @@ -67,4 +78,5 @@ config PCI_J721E_EP
> Say Y here if you want to support the TI J721E PCIe platform
> controller in endpoint mode. TI J721E PCIe controller uses Cadence PCIe
> core.
> +
> endmenu
> diff --git a/drivers/pci/controller/cadence/Makefile b/drivers/pci/controller/cadence/Makefile
> index 9bac5fb2f13d..4df4456d9539 100644
> --- a/drivers/pci/controller/cadence/Makefile
> +++ b/drivers/pci/controller/cadence/Makefile
> @@ -4,3 +4,4 @@ obj-$(CONFIG_PCIE_CADENCE_HOST) += pcie-cadence-host.o
> obj-$(CONFIG_PCIE_CADENCE_EP) += pcie-cadence-ep.o
> obj-$(CONFIG_PCIE_CADENCE_PLAT) += pcie-cadence-plat.o
> obj-$(CONFIG_PCI_J721E) += pci-j721e.o
> +obj-$(CONFIG_PCIE_SG2042) += pcie-sg2042.o
> diff --git a/drivers/pci/controller/cadence/pcie-sg2042.c b/drivers/pci/controller/cadence/pcie-sg2042.c
> new file mode 100644
> index 000000000000..fe434dc2967e
> --- /dev/null
> +++ b/drivers/pci/controller/cadence/pcie-sg2042.c
> @@ -0,0 +1,134 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * pcie-sg2042 - PCIe controller driver for Sophgo SG2042 SoC
> + *
> + * Copyright (C) 2025 Sophgo Technology Inc.
> + * Copyright (C) 2025 Chen Wang <unicorn_wang@xxxxxxxxxxx>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "pcie-cadence.h"
> +
> +/*
> + * SG2042 only support 4-byte aligned access, so for the rootbus (i.e. to read
> + * the Root Port itself, read32 is required. For non-rootbus (i.e. to read
> + * the PCIe peripheral registers, supports 1/2/4 byte aligned access, so
> + * directly using read should be fine.
> + *
> + * The same is true for write.
> + */
> +static int sg2042_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
> + int where, int size, u32 *value)
> +{
> + if (pci_is_root_bus(bus))
> + return pci_generic_config_read32(bus, devfn, where, size,
> + value);
> +
> + return pci_generic_config_read(bus, devfn, where, size, value);
> +}
> +
> +static int sg2042_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
> + int where, int size, u32 value)
> +{
> + if (pci_is_root_bus(bus))
> + return pci_generic_config_write32(bus, devfn, where, size,
> + value);
> +
> + return pci_generic_config_write(bus, devfn, where, size, value);
> +}
> +
> +static struct pci_ops sg2042_pcie_host_ops = {
> + .map_bus = cdns_pci_map_bus,
> + .read = sg2042_pcie_config_read,
> + .write = sg2042_pcie_config_write,
> +};
> +
> +static int sg2042_pcie_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct pci_host_bridge *bridge;
> + struct cdns_pcie *pcie;
> + struct cdns_pcie_rc *rc;
> + int ret;
> +
> + pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
> + if (!pcie)
> + return -ENOMEM;
> +
> + bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
> + if (!bridge) {
> + dev_err(dev, "Failed to alloc host bridge!\n");
Use dev_err_probe() here and below.
> + return -ENOMEM;
> + }
> +
> + bridge->ops = &sg2042_pcie_host_ops;
> +
> + rc = pci_host_bridge_priv(bridge);
> + pcie = &rc->pcie;
You are setting drvdata only below.
> + pcie->dev = dev;
> +
> + platform_set_drvdata(pdev, pcie);
> +
> + pm_runtime_enable(dev);
> +
> + ret = pm_runtime_get_sync(dev);
> + if (ret < 0) {
> + dev_err(dev, "pm_runtime_get_sync failed\n");
> + goto err_get_sync;
> + }
> +
Why do you need pm_runtime_get_sync()? DT binding doesn't provide a
power-domain, so you just need:
pm_runtime_set_active()
pm_runtime_no_callbacks()
devm_pm_runtime_enable()
> + ret = cdns_pcie_init_phy(dev, pcie);
> + if (ret) {
> + dev_err(dev, "Failed to init phy!\n");
> + goto err_get_sync;
> + }
> +
> + ret = cdns_pcie_host_setup(rc);
> + if (ret < 0) {
> + dev_err(dev, "Failed to setup host!\n");
> + goto err_host_setup;
> + }
> +
> + return 0;
> +
> +err_host_setup:
> + cdns_pcie_disable_phy(pcie);
> +
> +err_get_sync:
> + pm_runtime_put(dev);
> + pm_runtime_disable(dev);
> +
> + return ret;
> +}
> +
> +static void sg2042_pcie_shutdown(struct platform_device *pdev)
> +{
> + struct cdns_pcie *pcie = platform_get_drvdata(pdev);
> + struct device *dev = &pdev->dev;
> +
> + cdns_pcie_disable_phy(pcie);
> +
> + pm_runtime_put(dev);
> + pm_runtime_disable(dev);
You don't need these as per my above suggestion.
> +}
> +
> +static const struct of_device_id sg2042_pcie_of_match[] = {
> + { .compatible = "sophgo,sg2042-pcie-host" },
> + {},
> +};
> +
> +static struct platform_driver sg2042_pcie_driver = {
> + .driver = {
> + .name = "sg2042-pcie",
> + .of_match_table = sg2042_pcie_of_match,
> + .pm = &cdns_pcie_pm_ops,
> + },
> + .probe = sg2042_pcie_probe,
Why no remove()?
- Mani
--
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