1 /* 2 * Synopsys DW APB ICTL irqchip driver. 3 * 4 * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> 5 * 6 * based on GPL'ed 2.6 kernel sources 7 * (c) Marvell International Ltd. 8 * 9 * This file is licensed under the terms of the GNU General Public 10 * License version 2. This program is licensed "as is" without any 11 * warranty of any kind, whether express or implied. 12 */ 13 14 #include <linux/io.h> 15 #include <linux/irq.h> 16 #include <linux/irqchip.h> 17 #include <linux/irqchip/chained_irq.h> 18 #include <linux/of_address.h> 19 #include <linux/of_irq.h> 20 #include <linux/interrupt.h> 21 22 #define APB_INT_ENABLE_L 0x00 23 #define APB_INT_ENABLE_H 0x04 24 #define APB_INT_MASK_L 0x08 25 #define APB_INT_MASK_H 0x0c 26 #define APB_INT_FINALSTATUS_L 0x30 27 #define APB_INT_FINALSTATUS_H 0x34 28 #define APB_INT_BASE_OFFSET 0x04 29 30 /* irq domain of the primary interrupt controller. */ 31 static struct irq_domain *dw_apb_ictl_irq_domain; 32 33 static void __irq_entry dw_apb_ictl_handle_irq(struct pt_regs *regs) 34 { 35 struct irq_domain *d = dw_apb_ictl_irq_domain; 36 int n; 37 38 for (n = 0; n < d->revmap_size; n += 32) { 39 struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, n); 40 u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L); 41 42 while (stat) { 43 u32 hwirq = ffs(stat) - 1; 44 45 handle_domain_irq(d, hwirq, regs); 46 stat &= ~BIT(hwirq); 47 } 48 } 49 } 50 51 static void dw_apb_ictl_handle_irq_cascaded(struct irq_desc *desc) 52 { 53 struct irq_domain *d = irq_desc_get_handler_data(desc); 54 struct irq_chip *chip = irq_desc_get_chip(desc); 55 int n; 56 57 chained_irq_enter(chip, desc); 58 59 for (n = 0; n < d->revmap_size; n += 32) { 60 struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, n); 61 u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L); 62 63 while (stat) { 64 u32 hwirq = ffs(stat) - 1; 65 generic_handle_domain_irq(d, gc->irq_base + hwirq); 66 67 stat &= ~BIT(hwirq); 68 } 69 } 70 71 chained_irq_exit(chip, desc); 72 } 73 74 static int dw_apb_ictl_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, 75 unsigned int nr_irqs, void *arg) 76 { 77 int i, ret; 78 irq_hw_number_t hwirq; 79 unsigned int type = IRQ_TYPE_NONE; 80 struct irq_fwspec *fwspec = arg; 81 82 ret = irq_domain_translate_onecell(domain, fwspec, &hwirq, &type); 83 if (ret) 84 return ret; 85 86 for (i = 0; i < nr_irqs; i++) 87 irq_map_generic_chip(domain, virq + i, hwirq + i); 88 89 return 0; 90 } 91 92 static const struct irq_domain_ops dw_apb_ictl_irq_domain_ops = { 93 .translate = irq_domain_translate_onecell, 94 .alloc = dw_apb_ictl_irq_domain_alloc, 95 .free = irq_domain_free_irqs_top, 96 }; 97 98 #ifdef CONFIG_PM 99 static void dw_apb_ictl_resume(struct irq_data *d) 100 { 101 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); 102 struct irq_chip_type *ct = irq_data_get_chip_type(d); 103 104 irq_gc_lock(gc); 105 writel_relaxed(~0, gc->reg_base + ct->regs.enable); 106 writel_relaxed(*ct->mask_cache, gc->reg_base + ct->regs.mask); 107 irq_gc_unlock(gc); 108 } 109 #else 110 #define dw_apb_ictl_resume NULL 111 #endif /* CONFIG_PM */ 112 113 static int __init dw_apb_ictl_init(struct device_node *np, 114 struct device_node *parent) 115 { 116 const struct irq_domain_ops *domain_ops; 117 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; 118 struct resource r; 119 struct irq_domain *domain; 120 struct irq_chip_generic *gc; 121 void __iomem *iobase; 122 int ret, nrirqs, parent_irq, i; 123 u32 reg; 124 125 if (!parent) { 126 /* Used as the primary interrupt controller */ 127 parent_irq = 0; 128 domain_ops = &dw_apb_ictl_irq_domain_ops; 129 } else { 130 /* Map the parent interrupt for the chained handler */ 131 parent_irq = irq_of_parse_and_map(np, 0); 132 if (parent_irq <= 0) { 133 pr_err("%pOF: unable to parse irq\n", np); 134 return -EINVAL; 135 } 136 domain_ops = &irq_generic_chip_ops; 137 } 138 139 ret = of_address_to_resource(np, 0, &r); 140 if (ret) { 141 pr_err("%pOF: unable to get resource\n", np); 142 return ret; 143 } 144 145 if (!request_mem_region(r.start, resource_size(&r), np->full_name)) { 146 pr_err("%pOF: unable to request mem region\n", np); 147 return -ENOMEM; 148 } 149 150 iobase = ioremap(r.start, resource_size(&r)); 151 if (!iobase) { 152 pr_err("%pOF: unable to map resource\n", np); 153 ret = -ENOMEM; 154 goto err_release; 155 } 156 157 /* 158 * DW IP can be configured to allow 2-64 irqs. We can determine 159 * the number of irqs supported by writing into enable register 160 * and look for bits not set, as corresponding flip-flops will 161 * have been removed by synthesis tool. 162 */ 163 164 /* mask and enable all interrupts */ 165 writel_relaxed(~0, iobase + APB_INT_MASK_L); 166 writel_relaxed(~0, iobase + APB_INT_MASK_H); 167 writel_relaxed(~0, iobase + APB_INT_ENABLE_L); 168 writel_relaxed(~0, iobase + APB_INT_ENABLE_H); 169 170 reg = readl_relaxed(iobase + APB_INT_ENABLE_H); 171 if (reg) 172 nrirqs = 32 + fls(reg); 173 else 174 nrirqs = fls(readl_relaxed(iobase + APB_INT_ENABLE_L)); 175 176 domain = irq_domain_add_linear(np, nrirqs, domain_ops, NULL); 177 if (!domain) { 178 pr_err("%pOF: unable to add irq domain\n", np); 179 ret = -ENOMEM; 180 goto err_unmap; 181 } 182 183 ret = irq_alloc_domain_generic_chips(domain, 32, 1, np->name, 184 handle_level_irq, clr, 0, 185 IRQ_GC_INIT_MASK_CACHE); 186 if (ret) { 187 pr_err("%pOF: unable to alloc irq domain gc\n", np); 188 goto err_unmap; 189 } 190 191 for (i = 0; i < DIV_ROUND_UP(nrirqs, 32); i++) { 192 gc = irq_get_domain_generic_chip(domain, i * 32); 193 gc->reg_base = iobase + i * APB_INT_BASE_OFFSET; 194 gc->chip_types[0].regs.mask = APB_INT_MASK_L; 195 gc->chip_types[0].regs.enable = APB_INT_ENABLE_L; 196 gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit; 197 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit; 198 gc->chip_types[0].chip.irq_resume = dw_apb_ictl_resume; 199 } 200 201 if (parent_irq) { 202 irq_set_chained_handler_and_data(parent_irq, 203 dw_apb_ictl_handle_irq_cascaded, domain); 204 } else { 205 dw_apb_ictl_irq_domain = domain; 206 set_handle_irq(dw_apb_ictl_handle_irq); 207 } 208 209 return 0; 210 211 err_unmap: 212 iounmap(iobase); 213 err_release: 214 release_mem_region(r.start, resource_size(&r)); 215 return ret; 216 } 217 IRQCHIP_DECLARE(dw_apb_ictl, 218 "snps,dw-apb-ictl", dw_apb_ictl_init); 219