1 /* 2 * Xtensa MX interrupt distributor 3 * 4 * Copyright (C) 2002 - 2013 Tensilica, Inc. 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10 11 #include <linux/interrupt.h> 12 #include <linux/irqdomain.h> 13 #include <linux/irq.h> 14 #include <linux/irqchip.h> 15 #include <linux/of.h> 16 17 #include <asm/mxregs.h> 18 19 #define HW_IRQ_IPI_COUNT 2 20 #define HW_IRQ_MX_BASE 2 21 #define HW_IRQ_EXTERN_BASE 3 22 23 static DEFINE_PER_CPU(unsigned int, cached_irq_mask); 24 25 static int xtensa_mx_irq_map(struct irq_domain *d, unsigned int irq, 26 irq_hw_number_t hw) 27 { 28 if (hw < HW_IRQ_IPI_COUNT) { 29 struct irq_chip *irq_chip = d->host_data; 30 irq_set_chip_and_handler_name(irq, irq_chip, 31 handle_percpu_irq, "ipi"); 32 irq_set_status_flags(irq, IRQ_LEVEL); 33 return 0; 34 } 35 irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq))); 36 return xtensa_irq_map(d, irq, hw); 37 } 38 39 /* 40 * Device Tree IRQ specifier translation function which works with one or 41 * two cell bindings. First cell value maps directly to the hwirq number. 42 * Second cell if present specifies whether hwirq number is external (1) or 43 * internal (0). 44 */ 45 static int xtensa_mx_irq_domain_xlate(struct irq_domain *d, 46 struct device_node *ctrlr, 47 const u32 *intspec, unsigned int intsize, 48 unsigned long *out_hwirq, unsigned int *out_type) 49 { 50 return xtensa_irq_domain_xlate(intspec, intsize, 51 intspec[0], intspec[0] + HW_IRQ_EXTERN_BASE, 52 out_hwirq, out_type); 53 } 54 55 static const struct irq_domain_ops xtensa_mx_irq_domain_ops = { 56 .xlate = xtensa_mx_irq_domain_xlate, 57 .map = xtensa_mx_irq_map, 58 }; 59 60 void secondary_init_irq(void) 61 { 62 __this_cpu_write(cached_irq_mask, 63 XCHAL_INTTYPE_MASK_EXTERN_EDGE | 64 XCHAL_INTTYPE_MASK_EXTERN_LEVEL); 65 xtensa_set_sr(XCHAL_INTTYPE_MASK_EXTERN_EDGE | 66 XCHAL_INTTYPE_MASK_EXTERN_LEVEL, intenable); 67 } 68 69 static void xtensa_mx_irq_mask(struct irq_data *d) 70 { 71 unsigned int mask = 1u << d->hwirq; 72 73 if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE | 74 XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) { 75 unsigned int ext_irq = xtensa_get_ext_irq_no(d->hwirq); 76 77 if (ext_irq >= HW_IRQ_MX_BASE) { 78 set_er(1u << (ext_irq - HW_IRQ_MX_BASE), MIENG); 79 return; 80 } 81 } 82 mask = __this_cpu_read(cached_irq_mask) & ~mask; 83 __this_cpu_write(cached_irq_mask, mask); 84 xtensa_set_sr(mask, intenable); 85 } 86 87 static void xtensa_mx_irq_unmask(struct irq_data *d) 88 { 89 unsigned int mask = 1u << d->hwirq; 90 91 if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE | 92 XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) { 93 unsigned int ext_irq = xtensa_get_ext_irq_no(d->hwirq); 94 95 if (ext_irq >= HW_IRQ_MX_BASE) { 96 set_er(1u << (ext_irq - HW_IRQ_MX_BASE), MIENGSET); 97 return; 98 } 99 } 100 mask |= __this_cpu_read(cached_irq_mask); 101 __this_cpu_write(cached_irq_mask, mask); 102 xtensa_set_sr(mask, intenable); 103 } 104 105 static void xtensa_mx_irq_enable(struct irq_data *d) 106 { 107 xtensa_mx_irq_unmask(d); 108 } 109 110 static void xtensa_mx_irq_disable(struct irq_data *d) 111 { 112 xtensa_mx_irq_mask(d); 113 } 114 115 static void xtensa_mx_irq_ack(struct irq_data *d) 116 { 117 xtensa_set_sr(1 << d->hwirq, intclear); 118 } 119 120 static int xtensa_mx_irq_retrigger(struct irq_data *d) 121 { 122 unsigned int mask = 1u << d->hwirq; 123 124 if (WARN_ON(mask & ~XCHAL_INTTYPE_MASK_SOFTWARE)) 125 return 0; 126 xtensa_set_sr(mask, intset); 127 return 1; 128 } 129 130 static int xtensa_mx_irq_set_affinity(struct irq_data *d, 131 const struct cpumask *dest, bool force) 132 { 133 int cpu = cpumask_any_and(dest, cpu_online_mask); 134 unsigned mask = 1u << cpu; 135 136 set_er(mask, MIROUT(d->hwirq - HW_IRQ_MX_BASE)); 137 irq_data_update_effective_affinity(d, cpumask_of(cpu)); 138 139 return 0; 140 141 } 142 143 static struct irq_chip xtensa_mx_irq_chip = { 144 .name = "xtensa-mx", 145 .irq_enable = xtensa_mx_irq_enable, 146 .irq_disable = xtensa_mx_irq_disable, 147 .irq_mask = xtensa_mx_irq_mask, 148 .irq_unmask = xtensa_mx_irq_unmask, 149 .irq_ack = xtensa_mx_irq_ack, 150 .irq_retrigger = xtensa_mx_irq_retrigger, 151 .irq_set_affinity = xtensa_mx_irq_set_affinity, 152 }; 153 154 static void __init xtensa_mx_init_common(struct irq_domain *root_domain) 155 { 156 unsigned int i; 157 158 irq_set_default_host(root_domain); 159 secondary_init_irq(); 160 161 /* Initialize default IRQ routing to CPU 0 */ 162 for (i = 0; i < XCHAL_NUM_EXTINTERRUPTS; ++i) 163 set_er(1, MIROUT(i)); 164 } 165 166 int __init xtensa_mx_init_legacy(struct device_node *interrupt_parent) 167 { 168 struct irq_domain *root_domain = 169 irq_domain_add_legacy(NULL, NR_IRQS - 1, 1, 0, 170 &xtensa_mx_irq_domain_ops, 171 &xtensa_mx_irq_chip); 172 xtensa_mx_init_common(root_domain); 173 return 0; 174 } 175 176 static int __init xtensa_mx_init(struct device_node *np, 177 struct device_node *interrupt_parent) 178 { 179 struct irq_domain *root_domain = 180 irq_domain_add_linear(np, NR_IRQS, &xtensa_mx_irq_domain_ops, 181 &xtensa_mx_irq_chip); 182 xtensa_mx_init_common(root_domain); 183 return 0; 184 } 185 IRQCHIP_DECLARE(xtensa_mx_irq_chip, "cdns,xtensa-mx", xtensa_mx_init); 186