On 10/28/24 16:07, Andrea della Porta wrote: > The RaspberryPi RP1 is a PCI multi function device containing > peripherals ranging from Ethernet to USB controller, I2C, SPI > and others. > > Implement a bare minimum driver to operate the RP1, leveraging > actual OF based driver implementations for the on-board peripherals > by loading a devicetree overlay during driver probe. > > The peripherals are accessed by mapping MMIO registers starting > from PCI BAR1 region. > > With the overlay approach we can achieve more generic and agnostic > approach to managing this chipset, being that it is a PCI endpoint > and could possibly be reused in other hw implementations. The > presented approach is also used by Bootlin's Microchip LAN966x > patchset (see link) as well, for a similar chipset. > > Since the gpio line names should be provided by the user, there > is an interface through configfs that allows the userspace to > load a DT overlay that will provide gpio-line-names property. > The interface can be invoked like this: > > cat rpi-rp1-gpios-5-b.dtbo > /sys/kernel/config/rp1-cfg/gpio_set_names > > and is designed to be similar to what users are already used to > from distro with downstream kernel. > > For reasons why this driver is contained in drivers/misc, please > check the links. > > This driver is heavily based on downstream code from RaspberryPi > Foundation, and the original author is Phil Elwell. > > Link: https://datasheets.raspberrypi.com/rp1/rp1-peripherals.pdf > Link: https://lore.kernel.org/all/20240612140208.GC1504919@xxxxxxxxxx/ > Link: https://lore.kernel.org/all/83f7fa09-d0e6-4f36-a27d-cee08979be2a@xxxxxxxxxxxxxxxx/ > Link: https://lore.kernel.org/all/2024081356-mutable-everyday-6f9d@gregkh/ > Link: https://lore.kernel.org/all/20240808154658.247873-1-herve.codina@xxxxxxxxxxx/ > > Signed-off-by: Andrea della Porta <andrea.porta@xxxxxxxx> > --- > MAINTAINERS | 1 + > drivers/misc/Kconfig | 1 + > drivers/misc/Makefile | 1 + > drivers/misc/rp1/Kconfig | 21 ++ > drivers/misc/rp1/Makefile | 3 + > drivers/misc/rp1/rp1-pci.dtso | 8 + > drivers/misc/rp1/rp1_pci.c | 357 ++++++++++++++++++++++++++++++++++ > drivers/misc/rp1/rp1_pci.h | 14 ++ > drivers/pci/quirks.c | 1 + > include/linux/pci_ids.h | 3 + > 10 files changed, 410 insertions(+) > create mode 100644 drivers/misc/rp1/Kconfig > create mode 100644 drivers/misc/rp1/Makefile > create mode 100644 drivers/misc/rp1/rp1-pci.dtso > create mode 100644 drivers/misc/rp1/rp1_pci.c > create mode 100644 drivers/misc/rp1/rp1_pci.h > > diff --git a/MAINTAINERS b/MAINTAINERS > index 510a071ede78..032678fb2470 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -19389,6 +19389,7 @@ F: Documentation/devicetree/bindings/misc/pci1de4,1.yaml > F: Documentation/devicetree/bindings/pci/pci-ep-bus.yaml > F: Documentation/devicetree/bindings/pinctrl/raspberrypi,rp1-gpio.yaml > F: drivers/clk/clk-rp1.c > +F: drivers/misc/rp1/ > F: drivers/pinctrl/pinctrl-rp1.c > F: include/dt-bindings/clock/rp1.h > F: include/dt-bindings/misc/rp1.h > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig > index 3fe7e2a9bd29..ac85cb154100 100644 > --- a/drivers/misc/Kconfig > +++ b/drivers/misc/Kconfig > @@ -628,4 +628,5 @@ source "drivers/misc/uacce/Kconfig" > source "drivers/misc/pvpanic/Kconfig" > source "drivers/misc/mchp_pci1xxxx/Kconfig" > source "drivers/misc/keba/Kconfig" > +source "drivers/misc/rp1/Kconfig" > endmenu > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile > index a9f94525e181..ae86d69997b4 100644 > --- a/drivers/misc/Makefile > +++ b/drivers/misc/Makefile > @@ -72,3 +72,4 @@ obj-$(CONFIG_TPS6594_PFSM) += tps6594-pfsm.o > obj-$(CONFIG_NSM) += nsm.o > obj-$(CONFIG_MARVELL_CN10K_DPI) += mrvl_cn10k_dpi.o > obj-y += keba/ > +obj-$(CONFIG_MISC_RP1) += rp1/ > diff --git a/drivers/misc/rp1/Kconfig b/drivers/misc/rp1/Kconfig > new file mode 100644 > index 000000000000..39c4aa4bf634 > --- /dev/null > +++ b/drivers/misc/rp1/Kconfig > @@ -0,0 +1,21 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +# > +# RaspberryPi RP1 misc device > +# > + > +config MISC_RP1 > + tristate "RaspberryPi RP1 PCIe support" > + depends on OF_IRQ && PCI_MSI && PCI_QUIRKS > + select OF_OVERLAY > + select PCI_DYNAMIC_OF_NODES > + help > + Support the RP1 peripheral chip found on Raspberry Pi 5 board. > + > + This device supports several sub-devices including e.g. Ethernet > + controller, USB controller, I2C, SPI and UART. > + > + The driver is responsible for enabling the DT node once the PCIe > + endpoint has been configured, and handling interrupts. > + > + This driver uses an overlay to load other drivers to support for > + RP1 internal sub-devices. > diff --git a/drivers/misc/rp1/Makefile b/drivers/misc/rp1/Makefile > new file mode 100644 > index 000000000000..508b4cb05627 > --- /dev/null > +++ b/drivers/misc/rp1/Makefile > @@ -0,0 +1,3 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +obj-$(CONFIG_MISC_RP1) += rp1-pci.o > +rp1-pci-objs := rp1_pci.o rp1-pci.dtbo.o > diff --git a/drivers/misc/rp1/rp1-pci.dtso b/drivers/misc/rp1/rp1-pci.dtso > new file mode 100644 > index 000000000000..0bf2f4bb18e6 > --- /dev/null > +++ b/drivers/misc/rp1/rp1-pci.dtso > @@ -0,0 +1,8 @@ > +// SPDX-License-Identifier: (GPL-2.0 OR MIT) > + > +/* the dts overlay is included from the dts directory so > + * it can be possible to check it with CHECK_DTBS while > + * also compile it from the driver source directory. > + */ > + > +#include "arm64/broadcom/rp1.dtso" > diff --git a/drivers/misc/rp1/rp1_pci.c b/drivers/misc/rp1/rp1_pci.c > new file mode 100644 > index 000000000000..30d7a15dc7f1 > --- /dev/null > +++ b/drivers/misc/rp1/rp1_pci.c > @@ -0,0 +1,357 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2018-24 Raspberry Pi Ltd. > + * All rights reserved. > + */ > + > +#include <linux/err.h> > +#include <linux/interrupt.h> > +#include <linux/irq.h> > +#include <linux/irqchip/chained_irq.h> > +#include <linux/irqdomain.h> > +#include <linux/module.h> > +#include <linux/msi.h> > +#include <linux/of_platform.h> > +#include <linux/pci.h> > +#include <linux/platform_device.h> > + > +#include "rp1_pci.h" > + > +#define RP1_DRIVER_NAME "rp1" > + > +#define RP1_HW_IRQ_MASK GENMASK(5, 0) > + > +#define REG_SET 0x800 > +#define REG_CLR 0xc00 > + > +/* MSI-X CFG registers start at 0x8 */ > +#define MSIX_CFG(x) (0x8 + (4 * (x))) > + > +#define MSIX_CFG_IACK_EN BIT(3) > +#define MSIX_CFG_IACK BIT(2) > +#define MSIX_CFG_ENABLE BIT(0) > + > +/* Address map */ > +#define RP1_PCIE_APBS_BASE 0x108000 > + > +/* Interrupts */ > +#define RP1_INT_IO_BANK0 0 > +#define RP1_INT_IO_BANK1 1 > +#define RP1_INT_IO_BANK2 2 > +#define RP1_INT_AUDIO_IN 3 > +#define RP1_INT_AUDIO_OUT 4 > +#define RP1_INT_PWM0 5 > +#define RP1_INT_ETH 6 > +#define RP1_INT_I2C0 7 > +#define RP1_INT_I2C1 8 > +#define RP1_INT_I2C2 9 > +#define RP1_INT_I2C3 10 > +#define RP1_INT_I2C4 11 > +#define RP1_INT_I2C5 12 > +#define RP1_INT_I2C6 13 > +#define RP1_INT_I2S0 14 > +#define RP1_INT_I2S1 15 > +#define RP1_INT_I2S2 16 > +#define RP1_INT_SDIO0 17 > +#define RP1_INT_SDIO1 18 > +#define RP1_INT_SPI0 19 > +#define RP1_INT_SPI1 20 > +#define RP1_INT_SPI2 21 > +#define RP1_INT_SPI3 22 > +#define RP1_INT_SPI4 23 > +#define RP1_INT_SPI5 24 > +#define RP1_INT_UART0 25 > +#define RP1_INT_TIMER_0 26 > +#define RP1_INT_TIMER_1 27 > +#define RP1_INT_TIMER_2 28 > +#define RP1_INT_TIMER_3 29 > +#define RP1_INT_USBHOST0 30 > +#define RP1_INT_USBHOST0_0 31 > +#define RP1_INT_USBHOST0_1 32 > +#define RP1_INT_USBHOST0_2 33 > +#define RP1_INT_USBHOST0_3 34 > +#define RP1_INT_USBHOST1 35 > +#define RP1_INT_USBHOST1_0 36 > +#define RP1_INT_USBHOST1_1 37 > +#define RP1_INT_USBHOST1_2 38 > +#define RP1_INT_USBHOST1_3 39 > +#define RP1_INT_DMA 40 > +#define RP1_INT_PWM1 41 > +#define RP1_INT_UART1 42 > +#define RP1_INT_UART2 43 > +#define RP1_INT_UART3 44 > +#define RP1_INT_UART4 45 > +#define RP1_INT_UART5 46 > +#define RP1_INT_MIPI0 47 > +#define RP1_INT_MIPI1 48 > +#define RP1_INT_VIDEO_OUT 49 > +#define RP1_INT_PIO_0 50 > +#define RP1_INT_PIO_1 51 > +#define RP1_INT_ADC_FIFO 52 > +#define RP1_INT_PCIE_OUT 53 > +#define RP1_INT_SPI6 54 > +#define RP1_INT_SPI7 55 > +#define RP1_INT_SPI8 56 > +#define RP1_INT_SYSCFG 58 > +#define RP1_INT_CLOCKS_DEFAULT 59 > +#define RP1_INT_VBUSCTRL 60 > +#define RP1_INT_PROC_MISC 57 > +#define RP1_INT_END 61 > + How those interrupts are supposed to be used by rp1-pci.dtso (or from rp1.dtso)? include/dt-bindings/interrupt-controller/raspberrypi,rp1-interrupts.h ? > +struct rp1_dev { > + struct pci_dev *pdev; > + struct device *dev; > + struct irq_domain *domain; > + struct irq_data *pcie_irqds[64]; > + void __iomem *bar1; > + int ovcs_id; > + bool level_triggered_irq[RP1_INT_END]; > +}; > + > +static void msix_cfg_set(struct rp1_dev *rp1, unsigned int hwirq, u32 value) > +{ > + iowrite32(value, rp1->bar1 + RP1_PCIE_APBS_BASE + REG_SET + MSIX_CFG(hwirq)); > +} > + > +static void msix_cfg_clr(struct rp1_dev *rp1, unsigned int hwirq, u32 value) > +{ > + iowrite32(value, rp1->bar1 + RP1_PCIE_APBS_BASE + REG_CLR + MSIX_CFG(hwirq)); > +} > + > +static void rp1_mask_irq(struct irq_data *irqd) > +{ > + struct rp1_dev *rp1 = irqd->domain->host_data; > + struct irq_data *pcie_irqd = rp1->pcie_irqds[irqd->hwirq]; > + > + pci_msi_mask_irq(pcie_irqd); > +} > + > +static void rp1_unmask_irq(struct irq_data *irqd) > +{ > + struct rp1_dev *rp1 = irqd->domain->host_data; > + struct irq_data *pcie_irqd = rp1->pcie_irqds[irqd->hwirq]; > + > + pci_msi_unmask_irq(pcie_irqd); > +} > + > +static int rp1_irq_set_type(struct irq_data *irqd, unsigned int type) > +{ > + struct rp1_dev *rp1 = irqd->domain->host_data; > + unsigned int hwirq = (unsigned int)irqd->hwirq; > + > + switch (type) { > + case IRQ_TYPE_LEVEL_HIGH: > + dev_dbg(rp1->dev, "MSIX IACK EN for irq %d\n", hwirq); > + msix_cfg_set(rp1, hwirq, MSIX_CFG_IACK_EN); > + rp1->level_triggered_irq[hwirq] = true; > + break; > + case IRQ_TYPE_EDGE_RISING: > + msix_cfg_clr(rp1, hwirq, MSIX_CFG_IACK_EN); > + rp1->level_triggered_irq[hwirq] = false; > + break; > + default: > + return -EINVAL; > + } > + > + return 0; > +} > + > +static struct irq_chip rp1_irq_chip = { > + .name = "rp1_irq_chip", tabs instead of spaces here and below. > + .irq_mask = rp1_mask_irq, > + .irq_unmask = rp1_unmask_irq, > + .irq_set_type = rp1_irq_set_type, > +}; > + > +static void rp1_chained_handle_irq(struct irq_desc *desc) > +{ > + unsigned int hwirq = desc->irq_data.hwirq & RP1_HW_IRQ_MASK; > + struct rp1_dev *rp1 = irq_desc_get_handler_data(desc); > + struct irq_chip *chip = irq_desc_get_chip(desc); > + int virq; unsigned int > + > + chained_irq_enter(chip, desc); > + > + virq = irq_find_mapping(rp1->domain, hwirq); > + generic_handle_irq(virq); > + if (rp1->level_triggered_irq[hwirq]) > + msix_cfg_set(rp1, hwirq, MSIX_CFG_IACK); > + > + chained_irq_exit(chip, desc); > +} > + > +static int rp1_irq_xlate(struct irq_domain *d, struct device_node *node, > + const u32 *intspec, unsigned int intsize, > + unsigned long *out_hwirq, unsigned int *out_type) > +{ > + struct rp1_dev *rp1 = d->host_data; > + struct irq_data *pcie_irqd; > + unsigned long hwirq; > + int pcie_irq; > + int ret; > + > + ret = irq_domain_xlate_twocell(d, node, intspec, intsize, > + &hwirq, out_type); > + if (ret) > + return ret; > + > + pcie_irq = pci_irq_vector(rp1->pdev, hwirq); > + pcie_irqd = irq_get_irq_data(pcie_irq); > + rp1->pcie_irqds[hwirq] = pcie_irqd; > + *out_hwirq = hwirq; > + > + return 0; > +} > + > +static int rp1_irq_activate(struct irq_domain *d, struct irq_data *irqd, > + bool reserve) > +{ > + struct rp1_dev *rp1 = d->host_data; > + > + msix_cfg_set(rp1, (unsigned int)irqd->hwirq, MSIX_CFG_ENABLE); > + > + return 0; > +} > + > +static void rp1_irq_deactivate(struct irq_domain *d, struct irq_data *irqd) > +{ > + struct rp1_dev *rp1 = d->host_data; > + > + msix_cfg_clr(rp1, (unsigned int)irqd->hwirq, MSIX_CFG_ENABLE); > +} > + > +static const struct irq_domain_ops rp1_domain_ops = { > + .xlate = rp1_irq_xlate, > + .activate = rp1_irq_activate, > + .deactivate = rp1_irq_deactivate, > +}; > + > +static void rp1_unregister_interrupts(struct pci_dev *pdev) > +{ > + struct rp1_dev *rp1 = pci_get_drvdata(pdev); > + int irq, i; > + > + for (i = 0; i < RP1_INT_END; i++) { > + irq = irq_find_mapping(rp1->domain, i); > + irq_dispose_mapping(irq); > + } new line > + irq_domain_remove(rp1->domain); > + pci_free_irq_vectors(pdev); > +} > + > +static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id) > +{ > + u32 dtbo_size = __dtbo_rp1_pci_end - __dtbo_rp1_pci_begin; > + void *dtbo_start = __dtbo_rp1_pci_begin; > + struct device *dev = &pdev->dev; > + struct device_node *rp1_node; > + struct rp1_dev *rp1; > + int err = 0; > + int i; > + > + rp1_node = dev_of_node(dev); > + if (!rp1_node) { > + dev_err(dev, "Missing of_node for device\n"); > + return -EINVAL; > + } > + > + rp1 = devm_kzalloc(&pdev->dev, sizeof(*rp1), GFP_KERNEL); > + if (!rp1) > + return -ENOMEM; > + > + rp1->pdev = pdev; > + rp1->dev = &pdev->dev; rp1->dev is used only once in dev_dbg macro. You could drop it and extract struct device from rp1->pdev. > + > + if (pci_resource_len(pdev, 1) <= 0x10000) { > + dev_err(&pdev->dev, > + "Not initialised - is the firmware running?\n"); no need of a new line > + return -EINVAL; > + } > + > + err = pcim_enable_device(pdev); > + if (err < 0) { > + dev_err(&pdev->dev, "Enabling PCI device has failed: %d", > + err); ditto > + return err; > + } > + > + rp1->bar1 = pcim_iomap(pdev, 1, 0); > + if (!rp1->bar1) { > + dev_err(&pdev->dev, "Cannot map PCI BAR\n"); > + return -EIO; > + } > + > + pci_set_master(pdev); > + > + err = pci_alloc_irq_vectors(pdev, RP1_INT_END, RP1_INT_END, > + PCI_IRQ_MSIX); ditto > + if (err != RP1_INT_END) { an 'err' could be smaller then RP1_INT_END but still positive, thus .probe will return positive error code. > + dev_err(&pdev->dev, "pci_alloc_irq_vectors failed - %d\n", err); > + return err; > + } > + > + pci_set_drvdata(pdev, rp1); > + rp1->domain = irq_domain_add_linear(rp1_node, RP1_INT_END, > + &rp1_domain_ops, rp1); irq_domain_add_linear() could fail, check for error ... > + > + for (i = 0; i < RP1_INT_END; i++) { > + int irq = irq_create_mapping(rp1->domain, i); irq_create_mapping() returns 'unsigned int', maybe something like this: unsigned int irq = irq_create_mapping(rp1->domain, i); if (!irq) { err = -EINVAL; (or -ENOMEM) ... } > + > + if (irq < 0) { > + dev_err(&pdev->dev, "failed to create irq mapping\n"); > + err = irq; > + goto err_unload_overlay; goto err_unregister_interrupts; ? > + } new line, please > + irq_set_chip_and_handler(irq, &rp1_irq_chip, handle_level_irq); > + irq_set_probe(irq); > + irq_set_chained_handler_and_data(pci_irq_vector(pdev, i), > + rp1_chained_handle_irq, rp1); > + } > + > + err = of_overlay_fdt_apply(dtbo_start, dtbo_size, &rp1->ovcs_id, rp1_node); > + if (err) > + goto err_unregister_interrupts; > + > + err = of_platform_default_populate(rp1_node, NULL, dev); > + if (err) > + goto err_unload_overlay; > + > + return 0; > + > +err_unload_overlay: > + of_overlay_remove(&rp1->ovcs_id); > +err_unregister_interrupts: > + rp1_unregister_interrupts(pdev); > + > + return err; > +} > + > +static void rp1_remove(struct pci_dev *pdev) > +{ > + struct rp1_dev *rp1 = pci_get_drvdata(pdev); > + struct device *dev = &pdev->dev; > + > + of_platform_depopulate(dev); > + of_overlay_remove(&rp1->ovcs_id); > + rp1_unregister_interrupts(pdev); > +} > + > +static const struct pci_device_id dev_id_table[] = { > + { PCI_DEVICE(PCI_VENDOR_ID_RPI, PCI_DEVICE_ID_RPI_RP1_C0), }, > + { 0, } > +}; > +MODULE_DEVICE_TABLE(pci, dev_id_table); > + > +static struct pci_driver rp1_driver = { > + .name = RP1_DRIVER_NAME, > + .id_table = dev_id_table, > + .probe = rp1_probe, > + .remove = rp1_remove, > +}; > + > +module_pci_driver(rp1_driver); > + > +MODULE_AUTHOR("Phil Elwell <phil@xxxxxxxxxxxxxxx>"); > +MODULE_AUTHOR("Andrea della Porta <andrea.porta@xxxxxxxx>"); > +MODULE_DESCRIPTION("RP1 wrapper"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/misc/rp1/rp1_pci.h b/drivers/misc/rp1/rp1_pci.h > new file mode 100644 > index 000000000000..7982f13bad9b > --- /dev/null > +++ b/drivers/misc/rp1/rp1_pci.h > @@ -0,0 +1,14 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +/* > + * Copyright (c) 2018-24 Raspberry Pi Ltd. > + * All rights reserved. > + */ > + > +#ifndef _RP1_EXTERN_H_ > +#define _RP1_EXTERN_H_ > + > +extern char __dtbo_rp1_pci_begin[]; > +extern char __dtbo_rp1_pci_end[]; Could you point me where those two variables are used outside of rp1_pci.c? ~Stan
