Re: [PATCH 08/11] misc: rp1: RaspberryPi RP1 misc driver

Andrea della Porta
2024-08-23T10:26:00Z

On 11:55 Wed 21 Aug , Bjorn Helgaas wrote:
> On Tue, Aug 20, 2024 at 04:36:10PM +0200, Andrea della Porta wrote:
> > The RaspberryPi RP1 is ia PCI multi function device containing
>
> s/ia/a/
>
> > peripherals ranging from Ethernet to USB controller, I2C, SPI
> > and others.
>
> Add blank lines between paragraphs.
>
> > Implement a bare minimum driver to operate the RP1, leveraging
> > actual OF based driver implementations for the on-borad peripherals
>
> s/on-borad/on-board/
>
> > by loading a devicetree overlay during driver probe.
> > The peripherals are accessed by mapping MMIO registers starting
> > from PCI BAR1 region.
> > As a minimum driver, the peripherals will not be added to the
> > dtbo here, but in following patches.
>
> > +config MISC_RP1
> > + tristate "RaspberryPi RP1 PCIe support"
> > + depends on PCI && PCI_QUIRKS
> > + select OF
> > + select OF_OVERLAY
> > + select IRQ_DOMAIN
> > + select PCI_DYNAMIC_OF_NODES
> > + help
> > + Support for 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.
>
> s/support for/support/
>
> Add blank lines between paragraphs. Consider wrapping to fit in 80
> columns. Current width of 86 seems random.
>
> > diff --git a/drivers/misc/rp1/Makefile b/drivers/misc/rp1/Makefile
> > new file mode 100644
> > index 000000000000..e83854b4ed2c
> > --- /dev/null
> > +++ b/drivers/misc/rp1/Makefile
> > @@ -0,0 +1,3 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +rp1-pci-objs := rp1-pci.o rp1-pci.dtbo.o
> > +obj-$(CONFIG_MISC_RP1) += rp1-pci.o
> > diff --git a/drivers/misc/rp1/rp1-pci.c b/drivers/misc/rp1/rp1-pci.c
> > new file mode 100644
> > index 000000000000..a6093ba7e19a
> > --- /dev/null
> > +++ b/drivers/misc/rp1/rp1-pci.c
> > @@ -0,0 +1,333 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) 2018-22 Raspberry Pi Ltd.
>
> s/22/24/ ?
>
> > +#define RP1_B0_CHIP_ID 0x10001927
> > +#define RP1_C0_CHIP_ID 0x20001927
>
> Drop; both unused.
>
> > +#define RP1_PLATFORM_ASIC BIT(1)
> > +#define RP1_PLATFORM_FPGA BIT(0)
>
> Drop; both unused.
>
> > +#define RP1_SYSCLK_RATE 200000000
> > +#define RP1_SYSCLK_FPGA_RATE 60000000
>
> Drop; both unused.
>
> > +enum {
> > + SYSINFO_CHIP_ID_OFFSET = 0,
> > + SYSINFO_PLATFORM_OFFSET = 4,
> > +};
>
> Drop; unused.
>
> > +/* MSIX CFG registers start at 0x8 */
>
> s/MSIX/MSI-X/
>
> > +#define MSIX_CFG_TEST BIT(1)
>
> Unused.
>
> > +#define INTSTATL 0x108
> > +#define INTSTATH 0x10c
>
> Drop; both unused.
>
> > +static void dump_bar(struct pci_dev *pdev, unsigned int bar)
> > +{
> > + dev_info(&pdev->dev,
> > + "bar%d len 0x%llx, start 0x%llx, end 0x%llx, flags, 0x%lx\n",
>
> %pR does most of this for you.
>
> > +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;
> > + int ret = 0;
> > +
> > + 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:
> > + ret = -EINVAL;
>
> If you "return -EINVAL" directly here, I think you can drop "ret" and
> just "return 0" below.
>
> > + break;
> > + }
> > +
> > + return ret;
> > +}
>
> > +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) {
> > + 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 ret;
>
> if (ret)
> return ret;
>
> ...
> return 0;
>
> would make this easier to read and unindent the normal path.
>
> > + rp1->bar1 = pci_iomap(pdev, 1, 0);
>
> pcim_iomap()
>
> > + if (!rp1->bar1) {
> > + dev_err(&pdev->dev, "Cannot map PCI bar\n");
>
> s/bar/BAR/
>
> > +#define PCI_VENDOR_ID_RPI 0x1de4
> > +#define PCI_DEVICE_ID_RP1_C0 0x0001
>
> Device ID should include "RPI" as well.

Ack to all suggestions. Fixed in the next release, thanks.

Andrea