On Tue, 2021-03-09 at 11:10 +0000, Marc Zyngier wrote:
> On Wed, 24 Feb 2021 06:11:29 +0000,
> Jianjun Wang <jianjun.wang@xxxxxxxxxxxx> wrote:
> >
> > Add INTx support for MediaTek Gen3 PCIe controller.
> >
> > Signed-off-by: Jianjun Wang <jianjun.wang@xxxxxxxxxxxx>
> > Acked-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
> > ---
> > drivers/pci/controller/pcie-mediatek-gen3.c | 176 ++++++++++++++++++++
> > 1 file changed, 176 insertions(+)
> >
> > diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
> > index c602beb9afec..8b3b5f838b69 100644
> > --- a/drivers/pci/controller/pcie-mediatek-gen3.c
> > +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> > @@ -9,6 +9,9 @@
> > #include <linux/clk.h>
> > #include <linux/delay.h>
> > #include <linux/iopoll.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/irqdomain.h>
> > #include <linux/kernel.h>
> > #include <linux/module.h>
> > #include <linux/pci.h>
> > @@ -45,6 +48,13 @@
> > #define PCIE_LINK_STATUS_REG 0x154
> > #define PCIE_PORT_LINKUP BIT(8)
> >
> > +#define PCIE_INT_ENABLE_REG 0x180
> > +#define PCIE_INTX_SHIFT 24
> > +#define PCIE_INTX_ENABLE \
> > + GENMASK(PCIE_INTX_SHIFT + PCI_NUM_INTX - 1, PCIE_INTX_SHIFT)
> > +
> > +#define PCIE_INT_STATUS_REG 0x184
> > +
> > #define PCIE_TRANS_TABLE_BASE_REG 0x800
> > #define PCIE_ATR_SRC_ADDR_MSB_OFFSET 0x4
> > #define PCIE_ATR_TRSL_ADDR_LSB_OFFSET 0x8
> > @@ -73,6 +83,9 @@
> > * @phy: PHY controller block
> > * @clks: PCIe clocks
> > * @num_clks: PCIe clocks count for this port
> > + * @irq: PCIe controller interrupt number
> > + * @irq_lock: lock protecting IRQ register access
> > + * @intx_domain: legacy INTx IRQ domain
> > */
> > struct mtk_pcie_port {
> > struct device *dev;
> > @@ -83,6 +96,10 @@ struct mtk_pcie_port {
> > struct phy *phy;
> > struct clk_bulk_data *clks;
> > int num_clks;
> > +
> > + int irq;
> > + raw_spinlock_t irq_lock;
> > + struct irq_domain *intx_domain;
> > };
> >
> > /**
> > @@ -199,6 +216,11 @@ static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
> > val |= PCI_CLASS(PCI_CLASS_BRIDGE_PCI << 8);
> > writel_relaxed(val, port->base + PCIE_PCI_IDS_1);
> >
> > + /* Mask all INTx interrupts */
> > + val = readl_relaxed(port->base + PCIE_INT_ENABLE_REG);
> > + val &= ~PCIE_INTX_ENABLE;
> > + writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);
> > +
> > /* Assert all reset signals */
> > val = readl_relaxed(port->base + PCIE_RST_CTRL_REG);
> > val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB;
> > @@ -262,6 +284,154 @@ static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
> > return 0;
> > }
> >
> > +static int mtk_pcie_set_affinity(struct irq_data *data,
> > + const struct cpumask *mask, bool force)
> > +{
> > + return -EINVAL;
> > +}
> > +
> > +static void mtk_intx_mask(struct irq_data *data)
> > +{
> > + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> > + unsigned long flags;
> > + u32 val;
> > +
> > + raw_spin_lock_irqsave(&port->irq_lock, flags);
> > + val = readl_relaxed(port->base + PCIE_INT_ENABLE_REG);
> > + val &= ~BIT(data->hwirq + PCIE_INTX_SHIFT);
> > + writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);
> > + raw_spin_unlock_irqrestore(&port->irq_lock, flags);
> > +}
> > +
> > +static void mtk_intx_unmask(struct irq_data *data)
> > +{
> > + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> > + unsigned long flags;
> > + u32 val;
> > +
> > + raw_spin_lock_irqsave(&port->irq_lock, flags);
> > + val = readl_relaxed(port->base + PCIE_INT_ENABLE_REG);
> > + val |= BIT(data->hwirq + PCIE_INTX_SHIFT);
> > + writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);
> > + raw_spin_unlock_irqrestore(&port->irq_lock, flags);
> > +}
> > +
> > +/**
> > + * mtk_intx_eoi
> > + * @data: pointer to chip specific data
> > + *
> > + * As an emulated level IRQ, its interrupt status will remain
> > + * until the corresponding de-assert message is received; hence that
> > + * the status can only be cleared when the interrupt has been serviced.
> > + */
> > +static void mtk_intx_eoi(struct irq_data *data)
> > +{
> > + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> > + unsigned long hwirq;
> > +
> > + hwirq = data->hwirq + PCIE_INTX_SHIFT;
> > + writel_relaxed(BIT(hwirq), port->base + PCIE_INT_STATUS_REG);
> > +}
> > +
> > +static struct irq_chip mtk_intx_irq_chip = {
> > + .irq_enable = mtk_intx_unmask,
> > + .irq_disable = mtk_intx_mask,
>
> Please get rid of enable/disable. Given that you already have
> mask/unmask with the *same* implementation, this offers zero benefit.
Hi Marc,
Thanks for your review.
We need to support suspend/resume feature, the HW will be powered off
when the system is suspended, and its register value will be cleared. If
the enable/disable callback is not implemented, the unmask function will
not be called when the system resume, so INTx will remain disabled.
Can I keep the enable/disable callback? Or do we have any solutions to
restore the register value when the system resume?
Thanks.
>
> > + .irq_mask = mtk_intx_mask,
> > + .irq_unmask = mtk_intx_unmask,
> > + .irq_eoi = mtk_intx_eoi,
> > + .irq_set_affinity = mtk_pcie_set_affinity,
> > + .name = "INTx",
> > +};
>
> [...]
>
> Other that that, this look good to me.
>
> Thanks,
>
> M.
>
