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_platform.h> 11 #include <linux/errno.h> 12 #include <linux/err.h> 13 #include <linux/export.h> 14 #include <linux/slab.h> 15 #include <asm/prom.h> 16 #include <asm/hw_irq.h> 17 #include <asm/ppc-pci.h> 18 #include <asm/mpic_msgr.h> 19 20 #define MPIC_MSGR_REGISTERS_PER_BLOCK 4 21 #define MPIC_MSGR_STRIDE 0x10 22 #define MPIC_MSGR_MER_OFFSET 0x100 23 #define MSGR_INUSE 0 24 #define MSGR_FREE 1 25 26 static struct mpic_msgr **mpic_msgrs; 27 static unsigned int mpic_msgr_count; 28 static DEFINE_RAW_SPINLOCK(msgrs_lock); 29 30 static inline void _mpic_msgr_mer_write(struct mpic_msgr *msgr, u32 value) 31 { 32 out_be32(msgr->mer, value); 33 } 34 35 static inline u32 _mpic_msgr_mer_read(struct mpic_msgr *msgr) 36 { 37 return in_be32(msgr->mer); 38 } 39 40 static inline void _mpic_msgr_disable(struct mpic_msgr *msgr) 41 { 42 u32 mer = _mpic_msgr_mer_read(msgr); 43 44 _mpic_msgr_mer_write(msgr, mer & ~(1 << msgr->num)); 45 } 46 47 struct mpic_msgr *mpic_msgr_get(unsigned int reg_num) 48 { 49 unsigned long flags; 50 struct mpic_msgr *msgr; 51 52 /* Assume busy until proven otherwise. */ 53 msgr = ERR_PTR(-EBUSY); 54 55 if (reg_num >= mpic_msgr_count) 56 return ERR_PTR(-ENODEV); 57 58 raw_spin_lock_irqsave(&msgrs_lock, flags); 59 msgr = mpic_msgrs[reg_num]; 60 if (msgr->in_use == MSGR_FREE) 61 msgr->in_use = MSGR_INUSE; 62 raw_spin_unlock_irqrestore(&msgrs_lock, flags); 63 64 return msgr; 65 } 66 EXPORT_SYMBOL_GPL(mpic_msgr_get); 67 68 void mpic_msgr_put(struct mpic_msgr *msgr) 69 { 70 unsigned long flags; 71 72 raw_spin_lock_irqsave(&msgr->lock, flags); 73 msgr->in_use = MSGR_FREE; 74 _mpic_msgr_disable(msgr); 75 raw_spin_unlock_irqrestore(&msgr->lock, flags); 76 } 77 EXPORT_SYMBOL_GPL(mpic_msgr_put); 78 79 void mpic_msgr_enable(struct mpic_msgr *msgr) 80 { 81 unsigned long flags; 82 u32 mer; 83 84 raw_spin_lock_irqsave(&msgr->lock, flags); 85 mer = _mpic_msgr_mer_read(msgr); 86 _mpic_msgr_mer_write(msgr, mer | (1 << msgr->num)); 87 raw_spin_unlock_irqrestore(&msgr->lock, flags); 88 } 89 EXPORT_SYMBOL_GPL(mpic_msgr_enable); 90 91 void mpic_msgr_disable(struct mpic_msgr *msgr) 92 { 93 unsigned long flags; 94 95 raw_spin_lock_irqsave(&msgr->lock, flags); 96 _mpic_msgr_disable(msgr); 97 raw_spin_unlock_irqrestore(&msgr->lock, flags); 98 } 99 EXPORT_SYMBOL_GPL(mpic_msgr_disable); 100 101 /* The following three functions are used to compute the order and number of 102 * the message register blocks. They are clearly very inefficent. However, 103 * they are called *only* a few times during device initialization. 104 */ 105 static unsigned int mpic_msgr_number_of_blocks(void) 106 { 107 unsigned int count; 108 struct device_node *aliases; 109 110 count = 0; 111 aliases = of_find_node_by_name(NULL, "aliases"); 112 113 if (aliases) { 114 char buf[32]; 115 116 for (;;) { 117 snprintf(buf, sizeof(buf), "mpic-msgr-block%d", count); 118 if (!of_find_property(aliases, buf, NULL)) 119 break; 120 121 count += 1; 122 } 123 } 124 125 return count; 126 } 127 128 static unsigned int mpic_msgr_number_of_registers(void) 129 { 130 return mpic_msgr_number_of_blocks() * MPIC_MSGR_REGISTERS_PER_BLOCK; 131 } 132 133 static int mpic_msgr_block_number(struct device_node *node) 134 { 135 struct device_node *aliases; 136 unsigned int index, number_of_blocks; 137 char buf[64]; 138 139 number_of_blocks = mpic_msgr_number_of_blocks(); 140 aliases = of_find_node_by_name(NULL, "aliases"); 141 if (!aliases) 142 return -1; 143 144 for (index = 0; index < number_of_blocks; ++index) { 145 struct property *prop; 146 147 snprintf(buf, sizeof(buf), "mpic-msgr-block%d", index); 148 prop = of_find_property(aliases, buf, NULL); 149 if (node == of_find_node_by_path(prop->value)) 150 break; 151 } 152 153 return index == number_of_blocks ? -1 : index; 154 } 155 156 /* The probe function for a single message register block. 157 */ 158 static int mpic_msgr_probe(struct platform_device *dev) 159 { 160 void __iomem *msgr_block_addr; 161 int block_number; 162 struct resource rsrc; 163 unsigned int i; 164 unsigned int irq_index; 165 struct device_node *np = dev->dev.of_node; 166 unsigned int receive_mask; 167 const unsigned int *prop; 168 169 if (!np) { 170 dev_err(&dev->dev, "Device OF-Node is NULL"); 171 return -EFAULT; 172 } 173 174 /* Allocate the message register array upon the first device 175 * registered. 176 */ 177 if (!mpic_msgrs) { 178 mpic_msgr_count = mpic_msgr_number_of_registers(); 179 dev_info(&dev->dev, "Found %d message registers\n", 180 mpic_msgr_count); 181 182 mpic_msgrs = kcalloc(mpic_msgr_count, sizeof(*mpic_msgrs), 183 GFP_KERNEL); 184 if (!mpic_msgrs) { 185 dev_err(&dev->dev, 186 "No memory for message register blocks\n"); 187 return -ENOMEM; 188 } 189 } 190 dev_info(&dev->dev, "Of-device full name %pOF\n", np); 191 192 /* IO map the message register block. */ 193 of_address_to_resource(np, 0, &rsrc); 194 msgr_block_addr = ioremap(rsrc.start, resource_size(&rsrc)); 195 if (!msgr_block_addr) { 196 dev_err(&dev->dev, "Failed to iomap MPIC message registers"); 197 return -EFAULT; 198 } 199 200 /* Ensure the block has a defined order. */ 201 block_number = mpic_msgr_block_number(np); 202 if (block_number < 0) { 203 dev_err(&dev->dev, 204 "Failed to find message register block alias\n"); 205 return -ENODEV; 206 } 207 dev_info(&dev->dev, "Setting up message register block %d\n", 208 block_number); 209 210 /* Grab the receive mask which specifies what registers can receive 211 * interrupts. 212 */ 213 prop = of_get_property(np, "mpic-msgr-receive-mask", NULL); 214 receive_mask = (prop) ? *prop : 0xF; 215 216 /* Build up the appropriate message register data structures. */ 217 for (i = 0, irq_index = 0; i < MPIC_MSGR_REGISTERS_PER_BLOCK; ++i) { 218 struct mpic_msgr *msgr; 219 unsigned int reg_number; 220 221 msgr = kzalloc(sizeof(struct mpic_msgr), GFP_KERNEL); 222 if (!msgr) { 223 dev_err(&dev->dev, "No memory for message register\n"); 224 return -ENOMEM; 225 } 226 227 reg_number = block_number * MPIC_MSGR_REGISTERS_PER_BLOCK + i; 228 msgr->base = msgr_block_addr + i * MPIC_MSGR_STRIDE; 229 msgr->mer = (u32 *)((u8 *)msgr->base + MPIC_MSGR_MER_OFFSET); 230 msgr->in_use = MSGR_FREE; 231 msgr->num = i; 232 raw_spin_lock_init(&msgr->lock); 233 234 if (receive_mask & (1 << i)) { 235 msgr->irq = irq_of_parse_and_map(np, irq_index); 236 if (!msgr->irq) { 237 dev_err(&dev->dev, 238 "Missing interrupt specifier"); 239 kfree(msgr); 240 return -EFAULT; 241 } 242 irq_index += 1; 243 } else { 244 msgr->irq = 0; 245 } 246 247 mpic_msgrs[reg_number] = msgr; 248 mpic_msgr_disable(msgr); 249 dev_info(&dev->dev, "Register %d initialized: irq %d\n", 250 reg_number, msgr->irq); 251 252 } 253 254 return 0; 255 } 256 257 static const struct of_device_id mpic_msgr_ids[] = { 258 { 259 .compatible = "fsl,mpic-v3.1-msgr", 260 .data = NULL, 261 }, 262 {} 263 }; 264 265 static struct platform_driver mpic_msgr_driver = { 266 .driver = { 267 .name = "mpic-msgr", 268 .of_match_table = mpic_msgr_ids, 269 }, 270 .probe = mpic_msgr_probe, 271 }; 272 273 static __init int mpic_msgr_init(void) 274 { 275 return platform_driver_register(&mpic_msgr_driver); 276 } 277 subsys_initcall(mpic_msgr_init); 278