diff options
Diffstat (limited to 'drivers/irqchip/irq-dw-apb-ictl.c')
| -rw-r--r-- | drivers/irqchip/irq-dw-apb-ictl.c | 150 |
1 files changed, 150 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 00000000000..31e231e1f56 --- /dev/null +++ b/drivers/irqchip/irq-dw-apb-ictl.c @@ -0,0 +1,150 @@ +/* + * 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/chained_irq.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#include "irqchip.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 + +static void dw_apb_ictl_handler(unsigned int irq, struct irq_desc *desc) +{ + struct irq_chip *chip = irq_get_chip(irq); + struct irq_chip_generic *gc = irq_get_handler_data(irq); + struct irq_domain *d = gc->private; + u32 stat; + int n; + + chained_irq_enter(chip, desc); + + for (n = 0; n < gc->num_ct; n++) { + stat = readl_relaxed(gc->reg_base + + APB_INT_FINALSTATUS_L + 4 * n); + while (stat) { + u32 hwirq = ffs(stat) - 1; + generic_handle_irq(irq_find_mapping(d, + gc->irq_base + hwirq + 32 * n)); + stat &= ~(1 << hwirq); + } + } + + chained_irq_exit(chip, desc); +} + +static int __init dw_apb_ictl_init(struct device_node *np, + struct device_node *parent) +{ + 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, irq; + u32 reg; + + /* Map the parent interrupt for the chained handler */ + irq = irq_of_parse_and_map(np, 0); + if (irq <= 0) { + pr_err("%s: unable to parse irq\n", np->full_name); + return -EINVAL; + } + + ret = of_address_to_resource(np, 0, &r); + if (ret) { + pr_err("%s: unable to get resource\n", np->full_name); + return ret; + } + + if (!request_mem_region(r.start, resource_size(&r), np->full_name)) { + pr_err("%s: unable to request mem region\n", np->full_name); + return -ENOMEM; + } + + iobase = ioremap(r.start, resource_size(&r)); + if (!iobase) { + pr_err("%s: unable to map resource\n", np->full_name); + 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 sythesis tool. + */ + + /* mask and enable all interrupts */ + writel(~0, iobase + APB_INT_MASK_L); + writel(~0, iobase + APB_INT_MASK_H); + writel(~0, iobase + APB_INT_ENABLE_L); + writel(~0, iobase + APB_INT_ENABLE_H); + + reg = readl(iobase + APB_INT_ENABLE_H); + if (reg) + nrirqs = 32 + fls(reg); + else + nrirqs = fls(readl(iobase + APB_INT_ENABLE_L)); + + domain = irq_domain_add_linear(np, nrirqs, + &irq_generic_chip_ops, NULL); + if (!domain) { + pr_err("%s: unable to add irq domain\n", np->full_name); + ret = -ENOMEM; + goto err_unmap; + } + + ret = irq_alloc_domain_generic_chips(domain, 32, (nrirqs > 32) ? 2 : 1, + np->name, handle_level_irq, clr, 0, + IRQ_GC_INIT_MASK_CACHE); + if (ret) { + pr_err("%s: unable to alloc irq domain gc\n", np->full_name); + goto err_unmap; + } + + gc = irq_get_domain_generic_chip(domain, 0); + gc->private = domain; + gc->reg_base = iobase; + + gc->chip_types[0].regs.mask = APB_INT_MASK_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; + + if (nrirqs > 32) { + gc->chip_types[1].regs.mask = APB_INT_MASK_H; + gc->chip_types[1].chip.irq_mask = irq_gc_mask_set_bit; + gc->chip_types[1].chip.irq_unmask = irq_gc_mask_clr_bit; + } + + irq_set_handler_data(irq, gc); + irq_set_chained_handler(irq, dw_apb_ictl_handler); + + 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); |