1 // SPDX-License-Identifier: GPL-2.0-only 2 // 3 // Author: Steve Chen <schen@mvista.com> 4 // Copyright (C) 2008-2009, MontaVista Software, Inc. <source@mvista.com> 5 // Author: Bartosz Golaszewski <bgolaszewski@baylibre.com> 6 // Copyright (C) 2019, Texas Instruments 7 // 8 // TI Common Platform Interrupt Controller (cp_intc) driver 9 10 #include <linux/export.h> 11 #include <linux/init.h> 12 #include <linux/irq.h> 13 #include <linux/irqchip.h> 14 #include <linux/irqchip/irq-davinci-cp-intc.h> 15 #include <linux/irqdomain.h> 16 #include <linux/io.h> 17 #include <linux/of.h> 18 #include <linux/of_address.h> 19 #include <linux/of_irq.h> 20 21 #include <asm/exception.h> 22 23 #define DAVINCI_CP_INTC_CTRL 0x04 24 #define DAVINCI_CP_INTC_HOST_CTRL 0x0c 25 #define DAVINCI_CP_INTC_GLOBAL_ENABLE 0x10 26 #define DAVINCI_CP_INTC_SYS_STAT_IDX_CLR 0x24 27 #define DAVINCI_CP_INTC_SYS_ENABLE_IDX_SET 0x28 28 #define DAVINCI_CP_INTC_SYS_ENABLE_IDX_CLR 0x2c 29 #define DAVINCI_CP_INTC_HOST_ENABLE_IDX_SET 0x34 30 #define DAVINCI_CP_INTC_HOST_ENABLE_IDX_CLR 0x38 31 #define DAVINCI_CP_INTC_PRIO_IDX 0x80 32 #define DAVINCI_CP_INTC_SYS_STAT_CLR(n) (0x0280 + (n << 2)) 33 #define DAVINCI_CP_INTC_SYS_ENABLE_CLR(n) (0x0380 + (n << 2)) 34 #define DAVINCI_CP_INTC_CHAN_MAP(n) (0x0400 + (n << 2)) 35 #define DAVINCI_CP_INTC_SYS_POLARITY(n) (0x0d00 + (n << 2)) 36 #define DAVINCI_CP_INTC_SYS_TYPE(n) (0x0d80 + (n << 2)) 37 #define DAVINCI_CP_INTC_HOST_ENABLE(n) (0x1500 + (n << 2)) 38 #define DAVINCI_CP_INTC_PRI_INDX_MASK GENMASK(9, 0) 39 #define DAVINCI_CP_INTC_GPIR_NONE BIT(31) 40 41 static void __iomem *davinci_cp_intc_base; 42 static struct irq_domain *davinci_cp_intc_irq_domain; 43 44 static inline unsigned int davinci_cp_intc_read(unsigned int offset) 45 { 46 return readl_relaxed(davinci_cp_intc_base + offset); 47 } 48 49 static inline void davinci_cp_intc_write(unsigned long value, 50 unsigned int offset) 51 { 52 writel_relaxed(value, davinci_cp_intc_base + offset); 53 } 54 55 static void davinci_cp_intc_ack_irq(struct irq_data *d) 56 { 57 davinci_cp_intc_write(d->hwirq, DAVINCI_CP_INTC_SYS_STAT_IDX_CLR); 58 } 59 60 static void davinci_cp_intc_mask_irq(struct irq_data *d) 61 { 62 /* XXX don't know why we need to disable nIRQ here... */ 63 davinci_cp_intc_write(1, DAVINCI_CP_INTC_HOST_ENABLE_IDX_CLR); 64 davinci_cp_intc_write(d->hwirq, DAVINCI_CP_INTC_SYS_ENABLE_IDX_CLR); 65 davinci_cp_intc_write(1, DAVINCI_CP_INTC_HOST_ENABLE_IDX_SET); 66 } 67 68 static void davinci_cp_intc_unmask_irq(struct irq_data *d) 69 { 70 davinci_cp_intc_write(d->hwirq, DAVINCI_CP_INTC_SYS_ENABLE_IDX_SET); 71 } 72 73 static int davinci_cp_intc_set_irq_type(struct irq_data *d, 74 unsigned int flow_type) 75 { 76 unsigned int reg, mask, polarity, type; 77 78 reg = BIT_WORD(d->hwirq); 79 mask = BIT_MASK(d->hwirq); 80 polarity = davinci_cp_intc_read(DAVINCI_CP_INTC_SYS_POLARITY(reg)); 81 type = davinci_cp_intc_read(DAVINCI_CP_INTC_SYS_TYPE(reg)); 82 83 switch (flow_type) { 84 case IRQ_TYPE_EDGE_RISING: 85 polarity |= mask; 86 type |= mask; 87 break; 88 case IRQ_TYPE_EDGE_FALLING: 89 polarity &= ~mask; 90 type |= mask; 91 break; 92 case IRQ_TYPE_LEVEL_HIGH: 93 polarity |= mask; 94 type &= ~mask; 95 break; 96 case IRQ_TYPE_LEVEL_LOW: 97 polarity &= ~mask; 98 type &= ~mask; 99 break; 100 default: 101 return -EINVAL; 102 } 103 104 davinci_cp_intc_write(polarity, DAVINCI_CP_INTC_SYS_POLARITY(reg)); 105 davinci_cp_intc_write(type, DAVINCI_CP_INTC_SYS_TYPE(reg)); 106 107 return 0; 108 } 109 110 static struct irq_chip davinci_cp_intc_irq_chip = { 111 .name = "cp_intc", 112 .irq_ack = davinci_cp_intc_ack_irq, 113 .irq_mask = davinci_cp_intc_mask_irq, 114 .irq_unmask = davinci_cp_intc_unmask_irq, 115 .irq_set_type = davinci_cp_intc_set_irq_type, 116 .flags = IRQCHIP_SKIP_SET_WAKE, 117 }; 118 119 static asmlinkage void __exception_irq_entry 120 davinci_cp_intc_handle_irq(struct pt_regs *regs) 121 { 122 int gpir, irqnr, none; 123 124 /* 125 * The interrupt number is in first ten bits. The NONE field set to 1 126 * indicates a spurious irq. 127 */ 128 129 gpir = davinci_cp_intc_read(DAVINCI_CP_INTC_PRIO_IDX); 130 irqnr = gpir & DAVINCI_CP_INTC_PRI_INDX_MASK; 131 none = gpir & DAVINCI_CP_INTC_GPIR_NONE; 132 133 if (unlikely(none)) { 134 pr_err_once("%s: spurious irq!\n", __func__); 135 return; 136 } 137 138 generic_handle_domain_irq(davinci_cp_intc_irq_domain, irqnr); 139 } 140 141 static int davinci_cp_intc_host_map(struct irq_domain *h, unsigned int virq, 142 irq_hw_number_t hw) 143 { 144 pr_debug("cp_intc_host_map(%d, 0x%lx)\n", virq, hw); 145 146 irq_set_chip(virq, &davinci_cp_intc_irq_chip); 147 irq_set_probe(virq); 148 irq_set_handler(virq, handle_edge_irq); 149 150 return 0; 151 } 152 153 static const struct irq_domain_ops davinci_cp_intc_irq_domain_ops = { 154 .map = davinci_cp_intc_host_map, 155 .xlate = irq_domain_xlate_onetwocell, 156 }; 157 158 static int __init 159 davinci_cp_intc_do_init(const struct davinci_cp_intc_config *config, 160 struct device_node *node) 161 { 162 unsigned int num_regs = BITS_TO_LONGS(config->num_irqs); 163 int offset, irq_base; 164 void __iomem *req; 165 166 req = request_mem_region(config->reg.start, 167 resource_size(&config->reg), 168 "davinci-cp-intc"); 169 if (!req) { 170 pr_err("%s: register range busy\n", __func__); 171 return -EBUSY; 172 } 173 174 davinci_cp_intc_base = ioremap(config->reg.start, 175 resource_size(&config->reg)); 176 if (!davinci_cp_intc_base) { 177 pr_err("%s: unable to ioremap register range\n", __func__); 178 return -EINVAL; 179 } 180 181 davinci_cp_intc_write(0, DAVINCI_CP_INTC_GLOBAL_ENABLE); 182 183 /* Disable all host interrupts */ 184 davinci_cp_intc_write(0, DAVINCI_CP_INTC_HOST_ENABLE(0)); 185 186 /* Disable system interrupts */ 187 for (offset = 0; offset < num_regs; offset++) 188 davinci_cp_intc_write(~0, 189 DAVINCI_CP_INTC_SYS_ENABLE_CLR(offset)); 190 191 /* Set to normal mode, no nesting, no priority hold */ 192 davinci_cp_intc_write(0, DAVINCI_CP_INTC_CTRL); 193 davinci_cp_intc_write(0, DAVINCI_CP_INTC_HOST_CTRL); 194 195 /* Clear system interrupt status */ 196 for (offset = 0; offset < num_regs; offset++) 197 davinci_cp_intc_write(~0, 198 DAVINCI_CP_INTC_SYS_STAT_CLR(offset)); 199 200 /* Enable nIRQ (what about nFIQ?) */ 201 davinci_cp_intc_write(1, DAVINCI_CP_INTC_HOST_ENABLE_IDX_SET); 202 203 /* Default all priorities to channel 7. */ 204 num_regs = (config->num_irqs + 3) >> 2; /* 4 channels per register */ 205 for (offset = 0; offset < num_regs; offset++) 206 davinci_cp_intc_write(0x07070707, 207 DAVINCI_CP_INTC_CHAN_MAP(offset)); 208 209 irq_base = irq_alloc_descs(-1, 0, config->num_irqs, 0); 210 if (irq_base < 0) { 211 pr_err("%s: unable to allocate interrupt descriptors: %d\n", 212 __func__, irq_base); 213 return irq_base; 214 } 215 216 davinci_cp_intc_irq_domain = irq_domain_add_legacy( 217 node, config->num_irqs, irq_base, 0, 218 &davinci_cp_intc_irq_domain_ops, NULL); 219 220 if (!davinci_cp_intc_irq_domain) { 221 pr_err("%s: unable to create an interrupt domain\n", __func__); 222 return -EINVAL; 223 } 224 225 set_handle_irq(davinci_cp_intc_handle_irq); 226 227 /* Enable global interrupt */ 228 davinci_cp_intc_write(1, DAVINCI_CP_INTC_GLOBAL_ENABLE); 229 230 return 0; 231 } 232 233 int __init davinci_cp_intc_init(const struct davinci_cp_intc_config *config) 234 { 235 return davinci_cp_intc_do_init(config, NULL); 236 } 237 238 static int __init davinci_cp_intc_of_init(struct device_node *node, 239 struct device_node *parent) 240 { 241 struct davinci_cp_intc_config config = { }; 242 int ret; 243 244 ret = of_address_to_resource(node, 0, &config.reg); 245 if (ret) { 246 pr_err("%s: unable to get the register range from device-tree\n", 247 __func__); 248 return ret; 249 } 250 251 ret = of_property_read_u32(node, "ti,intc-size", &config.num_irqs); 252 if (ret) { 253 pr_err("%s: unable to read the 'ti,intc-size' property\n", 254 __func__); 255 return ret; 256 } 257 258 return davinci_cp_intc_do_init(&config, node); 259 } 260 IRQCHIP_DECLARE(cp_intc, "ti,cp-intc", davinci_cp_intc_of_init); 261