1 /* 2 * Copyright (C) 2014-2015 Toradex AG 3 * Author: Stefan Agner <stefan@agner.ch> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * 10 * IRQ chip driver for MSCM interrupt router available on Vybrid SoC's. 11 * The interrupt router is between the CPU's interrupt controller and the 12 * peripheral. The router allows to route the peripheral interrupts to 13 * one of the two available CPU's on Vybrid VF6xx SoC's (Cortex-A5 or 14 * Cortex-M4). The router will be configured transparently on a IRQ 15 * request. 16 * 17 * o All peripheral interrupts of the Vybrid SoC can be routed to 18 * CPU 0, CPU 1 or both. The routing is useful for dual-core 19 * variants of Vybrid SoC such as VF6xx. This driver routes the 20 * requested interrupt to the CPU currently running on. 21 * 22 * o It is required to setup the interrupt router even on single-core 23 * variants of Vybrid. 24 */ 25 26 #include <linux/cpu_pm.h> 27 #include <linux/io.h> 28 #include <linux/irq.h> 29 #include <linux/irqchip.h> 30 #include <linux/irqdomain.h> 31 #include <linux/mfd/syscon.h> 32 #include <dt-bindings/interrupt-controller/arm-gic.h> 33 #include <linux/of.h> 34 #include <linux/of_address.h> 35 #include <linux/slab.h> 36 #include <linux/regmap.h> 37 38 #define MSCM_CPxNUM 0x4 39 40 #define MSCM_IRSPRC(n) (0x80 + 2 * (n)) 41 #define MSCM_IRSPRC_CPEN_MASK 0x3 42 43 #define MSCM_IRSPRC_NUM 112 44 45 struct vf610_mscm_ir_chip_data { 46 void __iomem *mscm_ir_base; 47 u16 cpu_mask; 48 u16 saved_irsprc[MSCM_IRSPRC_NUM]; 49 bool is_nvic; 50 }; 51 52 static struct vf610_mscm_ir_chip_data *mscm_ir_data; 53 54 static inline void vf610_mscm_ir_save(struct vf610_mscm_ir_chip_data *data) 55 { 56 int i; 57 58 for (i = 0; i < MSCM_IRSPRC_NUM; i++) 59 data->saved_irsprc[i] = readw_relaxed(data->mscm_ir_base + MSCM_IRSPRC(i)); 60 } 61 62 static inline void vf610_mscm_ir_restore(struct vf610_mscm_ir_chip_data *data) 63 { 64 int i; 65 66 for (i = 0; i < MSCM_IRSPRC_NUM; i++) 67 writew_relaxed(data->saved_irsprc[i], data->mscm_ir_base + MSCM_IRSPRC(i)); 68 } 69 70 static int vf610_mscm_ir_notifier(struct notifier_block *self, 71 unsigned long cmd, void *v) 72 { 73 switch (cmd) { 74 case CPU_CLUSTER_PM_ENTER: 75 vf610_mscm_ir_save(mscm_ir_data); 76 break; 77 case CPU_CLUSTER_PM_ENTER_FAILED: 78 case CPU_CLUSTER_PM_EXIT: 79 vf610_mscm_ir_restore(mscm_ir_data); 80 break; 81 } 82 83 return NOTIFY_OK; 84 } 85 86 static struct notifier_block mscm_ir_notifier_block = { 87 .notifier_call = vf610_mscm_ir_notifier, 88 }; 89 90 static void vf610_mscm_ir_enable(struct irq_data *data) 91 { 92 irq_hw_number_t hwirq = data->hwirq; 93 struct vf610_mscm_ir_chip_data *chip_data = data->chip_data; 94 u16 irsprc; 95 96 irsprc = readw_relaxed(chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq)); 97 irsprc &= MSCM_IRSPRC_CPEN_MASK; 98 99 WARN_ON(irsprc & ~chip_data->cpu_mask); 100 101 writew_relaxed(chip_data->cpu_mask, 102 chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq)); 103 104 irq_chip_enable_parent(data); 105 } 106 107 static void vf610_mscm_ir_disable(struct irq_data *data) 108 { 109 irq_hw_number_t hwirq = data->hwirq; 110 struct vf610_mscm_ir_chip_data *chip_data = data->chip_data; 111 112 writew_relaxed(0x0, chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq)); 113 114 irq_chip_disable_parent(data); 115 } 116 117 static struct irq_chip vf610_mscm_ir_irq_chip = { 118 .name = "mscm-ir", 119 .irq_mask = irq_chip_mask_parent, 120 .irq_unmask = irq_chip_unmask_parent, 121 .irq_eoi = irq_chip_eoi_parent, 122 .irq_enable = vf610_mscm_ir_enable, 123 .irq_disable = vf610_mscm_ir_disable, 124 .irq_retrigger = irq_chip_retrigger_hierarchy, 125 .irq_set_affinity = irq_chip_set_affinity_parent, 126 }; 127 128 static int vf610_mscm_ir_domain_alloc(struct irq_domain *domain, unsigned int virq, 129 unsigned int nr_irqs, void *arg) 130 { 131 int i; 132 irq_hw_number_t hwirq; 133 struct of_phandle_args *irq_data = arg; 134 struct of_phandle_args gic_data; 135 136 if (irq_data->args_count != 2) 137 return -EINVAL; 138 139 hwirq = irq_data->args[0]; 140 for (i = 0; i < nr_irqs; i++) 141 irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i, 142 &vf610_mscm_ir_irq_chip, 143 domain->host_data); 144 145 gic_data.np = domain->parent->of_node; 146 147 if (mscm_ir_data->is_nvic) { 148 gic_data.args_count = 1; 149 gic_data.args[0] = irq_data->args[0]; 150 } else { 151 gic_data.args_count = 3; 152 gic_data.args[0] = GIC_SPI; 153 gic_data.args[1] = irq_data->args[0]; 154 gic_data.args[2] = irq_data->args[1]; 155 } 156 157 return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &gic_data); 158 } 159 160 static const struct irq_domain_ops mscm_irq_domain_ops = { 161 .xlate = irq_domain_xlate_twocell, 162 .alloc = vf610_mscm_ir_domain_alloc, 163 .free = irq_domain_free_irqs_common, 164 }; 165 166 static int __init vf610_mscm_ir_of_init(struct device_node *node, 167 struct device_node *parent) 168 { 169 struct irq_domain *domain, *domain_parent; 170 struct regmap *mscm_cp_regmap; 171 int ret, cpuid; 172 173 domain_parent = irq_find_host(parent); 174 if (!domain_parent) { 175 pr_err("vf610_mscm_ir: interrupt-parent not found\n"); 176 return -EINVAL; 177 } 178 179 mscm_ir_data = kzalloc(sizeof(*mscm_ir_data), GFP_KERNEL); 180 if (!mscm_ir_data) 181 return -ENOMEM; 182 183 mscm_ir_data->mscm_ir_base = of_io_request_and_map(node, 0, "mscm-ir"); 184 if (IS_ERR(mscm_ir_data->mscm_ir_base)) { 185 pr_err("vf610_mscm_ir: unable to map mscm register\n"); 186 ret = PTR_ERR(mscm_ir_data->mscm_ir_base); 187 goto out_free; 188 } 189 190 mscm_cp_regmap = syscon_regmap_lookup_by_phandle(node, "fsl,cpucfg"); 191 if (IS_ERR(mscm_cp_regmap)) { 192 ret = PTR_ERR(mscm_cp_regmap); 193 pr_err("vf610_mscm_ir: regmap lookup for cpucfg failed\n"); 194 goto out_unmap; 195 } 196 197 regmap_read(mscm_cp_regmap, MSCM_CPxNUM, &cpuid); 198 mscm_ir_data->cpu_mask = 0x1 << cpuid; 199 200 domain = irq_domain_add_hierarchy(domain_parent, 0, 201 MSCM_IRSPRC_NUM, node, 202 &mscm_irq_domain_ops, mscm_ir_data); 203 if (!domain) { 204 ret = -ENOMEM; 205 goto out_unmap; 206 } 207 208 if (of_device_is_compatible(domain->parent->of_node, "arm,armv7m-nvic")) 209 mscm_ir_data->is_nvic = true; 210 211 cpu_pm_register_notifier(&mscm_ir_notifier_block); 212 213 return 0; 214 215 out_unmap: 216 iounmap(mscm_ir_data->mscm_ir_base); 217 out_free: 218 kfree(mscm_ir_data); 219 return ret; 220 } 221 IRQCHIP_DECLARE(vf610_mscm_ir, "fsl,vf610-mscm-ir", vf610_mscm_ir_of_init); 222