1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2011-2012, Meador Inge, Mentor Graphics Corporation. 4 * 5 * Some ideas based on un-pushed work done by Vivek Mahajan, Jason Jin, and 6 * Mingkai Hu from Freescale Semiconductor, Inc. 7 */ 8 9 #include <linux/list.h> 10 #include <linux/of_address.h> 11 #include <linux/of_irq.h> 12 #include <linux/of_platform.h> 13 #include <linux/errno.h> 14 #include <linux/err.h> 15 #include <linux/export.h> 16 #include <linux/slab.h> 17 #include <asm/hw_irq.h> 18 #include <asm/ppc-pci.h> 19 #include <asm/mpic_msgr.h> 20 21 #define MPIC_MSGR_REGISTERS_PER_BLOCK 4 22 #define MPIC_MSGR_STRIDE 0x10 23 #define MPIC_MSGR_MER_OFFSET (0x100 / sizeof(u32)) 24 #define MSGR_INUSE 0 25 #define MSGR_FREE 1 26 27 static struct mpic_msgr **mpic_msgrs; 28 static unsigned int mpic_msgr_count; 29 static DEFINE_RAW_SPINLOCK(msgrs_lock); 30 31 static inline void _mpic_msgr_mer_write(struct mpic_msgr *msgr, u32 value) 32 { 33 out_be32(msgr->mer, value); 34 } 35 36 static inline u32 _mpic_msgr_mer_read(struct mpic_msgr *msgr) 37 { 38 return in_be32(msgr->mer); 39 } 40 41 static inline void _mpic_msgr_disable(struct mpic_msgr *msgr) 42 { 43 u32 mer = _mpic_msgr_mer_read(msgr); 44 45 _mpic_msgr_mer_write(msgr, mer & ~(1 << msgr->num)); 46 } 47 48 struct mpic_msgr *mpic_msgr_get(unsigned int reg_num) 49 { 50 unsigned long flags; 51 struct mpic_msgr *msgr; 52 53 /* Assume busy until proven otherwise. */ 54 msgr = ERR_PTR(-EBUSY); 55 56 if (reg_num >= mpic_msgr_count) 57 return ERR_PTR(-ENODEV); 58 59 raw_spin_lock_irqsave(&msgrs_lock, flags); 60 msgr = mpic_msgrs[reg_num]; 61 if (msgr->in_use == MSGR_FREE) 62 msgr->in_use = MSGR_INUSE; 63 raw_spin_unlock_irqrestore(&msgrs_lock, flags); 64 65 return msgr; 66 } 67 EXPORT_SYMBOL_GPL(mpic_msgr_get); 68 69 void mpic_msgr_put(struct mpic_msgr *msgr) 70 { 71 unsigned long flags; 72 73 raw_spin_lock_irqsave(&msgr->lock, flags); 74 msgr->in_use = MSGR_FREE; 75 _mpic_msgr_disable(msgr); 76 raw_spin_unlock_irqrestore(&msgr->lock, flags); 77 } 78 EXPORT_SYMBOL_GPL(mpic_msgr_put); 79 80 void mpic_msgr_enable(struct mpic_msgr *msgr) 81 { 82 unsigned long flags; 83 u32 mer; 84 85 raw_spin_lock_irqsave(&msgr->lock, flags); 86 mer = _mpic_msgr_mer_read(msgr); 87 _mpic_msgr_mer_write(msgr, mer | (1 << msgr->num)); 88 raw_spin_unlock_irqrestore(&msgr->lock, flags); 89 } 90 EXPORT_SYMBOL_GPL(mpic_msgr_enable); 91 92 void mpic_msgr_disable(struct mpic_msgr *msgr) 93 { 94 unsigned long flags; 95 96 raw_spin_lock_irqsave(&msgr->lock, flags); 97 _mpic_msgr_disable(msgr); 98 raw_spin_unlock_irqrestore(&msgr->lock, flags); 99 } 100 EXPORT_SYMBOL_GPL(mpic_msgr_disable); 101 102 /* The following three functions are used to compute the order and number of 103 * the message register blocks. They are clearly very inefficient. However, 104 * they are called *only* a few times during device initialization. 105 */ 106 static unsigned int mpic_msgr_number_of_blocks(void) 107 { 108 unsigned int count; 109 struct device_node *aliases; 110 111 count = 0; 112 aliases = of_find_node_by_name(NULL, "aliases"); 113 114 if (aliases) { 115 char buf[32]; 116 117 for (;;) { 118 snprintf(buf, sizeof(buf), "mpic-msgr-block%d", count); 119 if (!of_property_present(aliases, buf)) 120 break; 121 122 count += 1; 123 } 124 of_node_put(aliases); 125 } 126 127 return count; 128 } 129 130 static unsigned int mpic_msgr_number_of_registers(void) 131 { 132 return mpic_msgr_number_of_blocks() * MPIC_MSGR_REGISTERS_PER_BLOCK; 133 } 134 135 static int mpic_msgr_block_number(struct device_node *node) 136 { 137 struct device_node *aliases; 138 unsigned int index, number_of_blocks; 139 char buf[64]; 140 141 number_of_blocks = mpic_msgr_number_of_blocks(); 142 aliases = of_find_node_by_name(NULL, "aliases"); 143 if (!aliases) 144 return -1; 145 146 for (index = 0; index < number_of_blocks; ++index) { 147 struct property *prop; 148 struct device_node *tn; 149 150 snprintf(buf, sizeof(buf), "mpic-msgr-block%d", index); 151 prop = of_find_property(aliases, buf, NULL); 152 tn = of_find_node_by_path(prop->value); 153 if (node == tn) { 154 of_node_put(tn); 155 break; 156 } 157 of_node_put(tn); 158 } 159 of_node_put(aliases); 160 161 return index == number_of_blocks ? -1 : index; 162 } 163 164 /* The probe function for a single message register block. 165 */ 166 static int mpic_msgr_probe(struct platform_device *dev) 167 { 168 void __iomem *msgr_block_addr; 169 int block_number; 170 struct resource rsrc; 171 unsigned int i; 172 unsigned int irq_index; 173 struct device_node *np = dev->dev.of_node; 174 unsigned int receive_mask; 175 const unsigned int *prop; 176 177 if (!np) { 178 dev_err(&dev->dev, "Device OF-Node is NULL"); 179 return -EFAULT; 180 } 181 182 /* Allocate the message register array upon the first device 183 * registered. 184 */ 185 if (!mpic_msgrs) { 186 mpic_msgr_count = mpic_msgr_number_of_registers(); 187 dev_info(&dev->dev, "Found %d message registers\n", 188 mpic_msgr_count); 189 190 mpic_msgrs = kcalloc(mpic_msgr_count, sizeof(*mpic_msgrs), 191 GFP_KERNEL); 192 if (!mpic_msgrs) { 193 dev_err(&dev->dev, 194 "No memory for message register blocks\n"); 195 return -ENOMEM; 196 } 197 } 198 dev_info(&dev->dev, "Of-device full name %pOF\n", np); 199 200 /* IO map the message register block. */ 201 of_address_to_resource(np, 0, &rsrc); 202 msgr_block_addr = devm_ioremap(&dev->dev, rsrc.start, resource_size(&rsrc)); 203 if (!msgr_block_addr) { 204 dev_err(&dev->dev, "Failed to iomap MPIC message registers"); 205 return -EFAULT; 206 } 207 208 /* Ensure the block has a defined order. */ 209 block_number = mpic_msgr_block_number(np); 210 if (block_number < 0) { 211 dev_err(&dev->dev, 212 "Failed to find message register block alias\n"); 213 return -ENODEV; 214 } 215 dev_info(&dev->dev, "Setting up message register block %d\n", 216 block_number); 217 218 /* Grab the receive mask which specifies what registers can receive 219 * interrupts. 220 */ 221 prop = of_get_property(np, "mpic-msgr-receive-mask", NULL); 222 receive_mask = (prop) ? *prop : 0xF; 223 224 /* Build up the appropriate message register data structures. */ 225 for (i = 0, irq_index = 0; i < MPIC_MSGR_REGISTERS_PER_BLOCK; ++i) { 226 struct mpic_msgr *msgr; 227 unsigned int reg_number; 228 229 msgr = kzalloc(sizeof(struct mpic_msgr), GFP_KERNEL); 230 if (!msgr) { 231 dev_err(&dev->dev, "No memory for message register\n"); 232 return -ENOMEM; 233 } 234 235 reg_number = block_number * MPIC_MSGR_REGISTERS_PER_BLOCK + i; 236 msgr->base = msgr_block_addr + i * MPIC_MSGR_STRIDE; 237 msgr->mer = msgr->base + MPIC_MSGR_MER_OFFSET; 238 msgr->in_use = MSGR_FREE; 239 msgr->num = i; 240 raw_spin_lock_init(&msgr->lock); 241 242 if (receive_mask & (1 << i)) { 243 msgr->irq = irq_of_parse_and_map(np, irq_index); 244 if (!msgr->irq) { 245 dev_err(&dev->dev, 246 "Missing interrupt specifier"); 247 kfree(msgr); 248 return -EFAULT; 249 } 250 irq_index += 1; 251 } else { 252 msgr->irq = 0; 253 } 254 255 mpic_msgrs[reg_number] = msgr; 256 mpic_msgr_disable(msgr); 257 dev_info(&dev->dev, "Register %d initialized: irq %d\n", 258 reg_number, msgr->irq); 259 260 } 261 262 return 0; 263 } 264 265 static const struct of_device_id mpic_msgr_ids[] = { 266 { 267 .compatible = "fsl,mpic-v3.1-msgr", 268 .data = NULL, 269 }, 270 {} 271 }; 272 273 static struct platform_driver mpic_msgr_driver = { 274 .driver = { 275 .name = "mpic-msgr", 276 .of_match_table = mpic_msgr_ids, 277 }, 278 .probe = mpic_msgr_probe, 279 }; 280 281 static __init int mpic_msgr_init(void) 282 { 283 return platform_driver_register(&mpic_msgr_driver); 284 } 285 subsys_initcall(mpic_msgr_init); 286