diff options
Diffstat (limited to 'arch/powerpc/platforms/82xx/pq2ads-pci-pic.c')
| -rw-r--r-- | arch/powerpc/platforms/82xx/pq2ads-pci-pic.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c b/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c new file mode 100644 index 000000000..cf3210042 --- /dev/null +++ b/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PQ2 ADS-style PCI interrupt controller + * + * Copyright 2007 Freescale Semiconductor, Inc. + * Author: Scott Wood <scottwood@freescale.com> + * + * Loosely based on mpc82xx ADS support by Vitaly Bordug <vbordug@ru.mvista.com> + * Copyright (c) 2006 MontaVista Software, Inc. + */ + +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/irq.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/of_irq.h> + +#include <asm/io.h> +#include <asm/cpm2.h> + +#include "pq2.h" + +static DEFINE_RAW_SPINLOCK(pci_pic_lock); + +struct pq2ads_pci_pic { + struct device_node *node; + struct irq_domain *host; + + struct { + u32 stat; + u32 mask; + } __iomem *regs; +}; + +#define NUM_IRQS 32 + +static void pq2ads_pci_mask_irq(struct irq_data *d) +{ + struct pq2ads_pci_pic *priv = irq_data_get_irq_chip_data(d); + int irq = NUM_IRQS - irqd_to_hwirq(d) - 1; + + if (irq != -1) { + unsigned long flags; + raw_spin_lock_irqsave(&pci_pic_lock, flags); + + setbits32(&priv->regs->mask, 1 << irq); + mb(); + + raw_spin_unlock_irqrestore(&pci_pic_lock, flags); + } +} + +static void pq2ads_pci_unmask_irq(struct irq_data *d) +{ + struct pq2ads_pci_pic *priv = irq_data_get_irq_chip_data(d); + int irq = NUM_IRQS - irqd_to_hwirq(d) - 1; + + if (irq != -1) { + unsigned long flags; + + raw_spin_lock_irqsave(&pci_pic_lock, flags); + clrbits32(&priv->regs->mask, 1 << irq); + raw_spin_unlock_irqrestore(&pci_pic_lock, flags); + } +} + +static struct irq_chip pq2ads_pci_ic = { + .name = "PQ2 ADS PCI", + .irq_mask = pq2ads_pci_mask_irq, + .irq_mask_ack = pq2ads_pci_mask_irq, + .irq_ack = pq2ads_pci_mask_irq, + .irq_unmask = pq2ads_pci_unmask_irq, + .irq_enable = pq2ads_pci_unmask_irq, + .irq_disable = pq2ads_pci_mask_irq +}; + +static void pq2ads_pci_irq_demux(struct irq_desc *desc) +{ + struct pq2ads_pci_pic *priv = irq_desc_get_handler_data(desc); + u32 stat, mask, pend; + int bit; + + for (;;) { + stat = in_be32(&priv->regs->stat); + mask = in_be32(&priv->regs->mask); + + pend = stat & ~mask; + + if (!pend) + break; + + for (bit = 0; pend != 0; ++bit, pend <<= 1) { + if (pend & 0x80000000) + generic_handle_domain_irq(priv->host, bit); + } + } +} + +static int pci_pic_host_map(struct irq_domain *h, unsigned int virq, + irq_hw_number_t hw) +{ + irq_set_status_flags(virq, IRQ_LEVEL); + irq_set_chip_data(virq, h->host_data); + irq_set_chip_and_handler(virq, &pq2ads_pci_ic, handle_level_irq); + return 0; +} + +static const struct irq_domain_ops pci_pic_host_ops = { + .map = pci_pic_host_map, +}; + +int __init pq2ads_pci_init_irq(void) +{ + struct pq2ads_pci_pic *priv; + struct irq_domain *host; + struct device_node *np; + int ret = -ENODEV; + int irq; + + np = of_find_compatible_node(NULL, NULL, "fsl,pq2ads-pci-pic"); + if (!np) { + printk(KERN_ERR "No pci pic node in device tree.\n"); + goto out; + } + + irq = irq_of_parse_and_map(np, 0); + if (!irq) { + printk(KERN_ERR "No interrupt in pci pic node.\n"); + goto out_put_node; + } + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) { + ret = -ENOMEM; + goto out_unmap_irq; + } + + /* PCI interrupt controller registers: status and mask */ + priv->regs = of_iomap(np, 0); + if (!priv->regs) { + printk(KERN_ERR "Cannot map PCI PIC registers.\n"); + goto out_free_kmalloc; + } + + /* mask all PCI interrupts */ + out_be32(&priv->regs->mask, ~0); + mb(); + + host = irq_domain_add_linear(np, NUM_IRQS, &pci_pic_host_ops, priv); + if (!host) { + ret = -ENOMEM; + goto out_unmap_regs; + } + + priv->host = host; + irq_set_handler_data(irq, priv); + irq_set_chained_handler(irq, pq2ads_pci_irq_demux); + ret = 0; + goto out_put_node; + +out_unmap_regs: + iounmap(priv->regs); +out_free_kmalloc: + kfree(priv); +out_unmap_irq: + irq_dispose_mapping(irq); +out_put_node: + of_node_put(np); +out: + return ret; +} |