diff options
Diffstat (limited to 'drivers/irqchip/irq-dw-apb-ictl.c')
| -rw-r--r-- | drivers/irqchip/irq-dw-apb-ictl.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-dw-apb-ictl.c b/drivers/irqchip/irq-dw-apb-ictl.c new file mode 100644 index 000000000..54b09d6c4 --- /dev/null +++ b/drivers/irqchip/irq-dw-apb-ictl.c @@ -0,0 +1,219 @@ +/* + * Synopsys DW APB ICTL irqchip driver. + * + * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> + * + * based on GPL'ed 2.6 kernel sources + * (c) Marvell International Ltd. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/interrupt.h> + +#define APB_INT_ENABLE_L 0x00 +#define APB_INT_ENABLE_H 0x04 +#define APB_INT_MASK_L 0x08 +#define APB_INT_MASK_H 0x0c +#define APB_INT_FINALSTATUS_L 0x30 +#define APB_INT_FINALSTATUS_H 0x34 +#define APB_INT_BASE_OFFSET 0x04 + +/* irq domain of the primary interrupt controller. */ +static struct irq_domain *dw_apb_ictl_irq_domain; + +static void __irq_entry dw_apb_ictl_handle_irq(struct pt_regs *regs) +{ + struct irq_domain *d = dw_apb_ictl_irq_domain; + int n; + + for (n = 0; n < d->revmap_size; n += 32) { + struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, n); + u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L); + + while (stat) { + u32 hwirq = ffs(stat) - 1; + + handle_domain_irq(d, hwirq, regs); + stat &= ~BIT(hwirq); + } + } +} + +static void dw_apb_ictl_handle_irq_cascaded(struct irq_desc *desc) +{ + struct irq_domain *d = irq_desc_get_handler_data(desc); + struct irq_chip *chip = irq_desc_get_chip(desc); + int n; + + chained_irq_enter(chip, desc); + + for (n = 0; n < d->revmap_size; n += 32) { + struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, n); + u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L); + + while (stat) { + u32 hwirq = ffs(stat) - 1; + u32 virq = irq_find_mapping(d, gc->irq_base + hwirq); + + generic_handle_irq(virq); + stat &= ~BIT(hwirq); + } + } + + chained_irq_exit(chip, desc); +} + +static int dw_apb_ictl_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + int i, ret; + irq_hw_number_t hwirq; + unsigned int type = IRQ_TYPE_NONE; + struct irq_fwspec *fwspec = arg; + + ret = irq_domain_translate_onecell(domain, fwspec, &hwirq, &type); + if (ret) + return ret; + + for (i = 0; i < nr_irqs; i++) + irq_map_generic_chip(domain, virq + i, hwirq + i); + + return 0; +} + +static const struct irq_domain_ops dw_apb_ictl_irq_domain_ops = { + .translate = irq_domain_translate_onecell, + .alloc = dw_apb_ictl_irq_domain_alloc, + .free = irq_domain_free_irqs_top, +}; + +#ifdef CONFIG_PM +static void dw_apb_ictl_resume(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + struct irq_chip_type *ct = irq_data_get_chip_type(d); + + irq_gc_lock(gc); + writel_relaxed(~0, gc->reg_base + ct->regs.enable); + writel_relaxed(*ct->mask_cache, gc->reg_base + ct->regs.mask); + irq_gc_unlock(gc); +} +#else +#define dw_apb_ictl_resume NULL +#endif /* CONFIG_PM */ + +static int __init dw_apb_ictl_init(struct device_node *np, + struct device_node *parent) +{ + const struct irq_domain_ops *domain_ops; + unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; + struct resource r; + struct irq_domain *domain; + struct irq_chip_generic *gc; + void __iomem *iobase; + int ret, nrirqs, parent_irq, i; + u32 reg; + + if (!parent) { + /* Used as the primary interrupt controller */ + parent_irq = 0; + domain_ops = &dw_apb_ictl_irq_domain_ops; + } else { + /* Map the parent interrupt for the chained handler */ + parent_irq = irq_of_parse_and_map(np, 0); + if (parent_irq <= 0) { + pr_err("%pOF: unable to parse irq\n", np); + return -EINVAL; + } + domain_ops = &irq_generic_chip_ops; + } + + ret = of_address_to_resource(np, 0, &r); + if (ret) { + pr_err("%pOF: unable to get resource\n", np); + return ret; + } + + if (!request_mem_region(r.start, resource_size(&r), np->full_name)) { + pr_err("%pOF: unable to request mem region\n", np); + return -ENOMEM; + } + + iobase = ioremap(r.start, resource_size(&r)); + if (!iobase) { + pr_err("%pOF: unable to map resource\n", np); + ret = -ENOMEM; + goto err_release; + } + + /* + * DW IP can be configured to allow 2-64 irqs. We can determine + * the number of irqs supported by writing into enable register + * and look for bits not set, as corresponding flip-flops will + * have been removed by synthesis tool. + */ + + /* mask and enable all interrupts */ + writel_relaxed(~0, iobase + APB_INT_MASK_L); + writel_relaxed(~0, iobase + APB_INT_MASK_H); + writel_relaxed(~0, iobase + APB_INT_ENABLE_L); + writel_relaxed(~0, iobase + APB_INT_ENABLE_H); + + reg = readl_relaxed(iobase + APB_INT_ENABLE_H); + if (reg) + nrirqs = 32 + fls(reg); + else + nrirqs = fls(readl_relaxed(iobase + APB_INT_ENABLE_L)); + + domain = irq_domain_add_linear(np, nrirqs, domain_ops, NULL); + if (!domain) { + pr_err("%pOF: unable to add irq domain\n", np); + ret = -ENOMEM; + goto err_unmap; + } + + ret = irq_alloc_domain_generic_chips(domain, 32, 1, np->name, + handle_level_irq, clr, 0, + IRQ_GC_INIT_MASK_CACHE); + if (ret) { + pr_err("%pOF: unable to alloc irq domain gc\n", np); + goto err_unmap; + } + + for (i = 0; i < DIV_ROUND_UP(nrirqs, 32); i++) { + gc = irq_get_domain_generic_chip(domain, i * 32); + gc->reg_base = iobase + i * APB_INT_BASE_OFFSET; + gc->chip_types[0].regs.mask = APB_INT_MASK_L; + gc->chip_types[0].regs.enable = APB_INT_ENABLE_L; + gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit; + gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit; + gc->chip_types[0].chip.irq_resume = dw_apb_ictl_resume; + } + + if (parent_irq) { + irq_set_chained_handler_and_data(parent_irq, + dw_apb_ictl_handle_irq_cascaded, domain); + } else { + dw_apb_ictl_irq_domain = domain; + set_handle_irq(dw_apb_ictl_handle_irq); + } + + return 0; + +err_unmap: + iounmap(iobase); +err_release: + release_mem_region(r.start, resource_size(&r)); + return ret; +} +IRQCHIP_DECLARE(dw_apb_ictl, + "snps,dw-apb-ictl", dw_apb_ictl_init); |