1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright 2011-2012, Meador Inge, Mentor Graphics Corporation.
5 * Some ideas based on un-pushed work done by Vivek Mahajan, Jason Jin, and
6 * Mingkai Hu from Freescale Semiconductor, Inc.
9 #include <linux/list.h>
11 #include <linux/of_address.h>
12 #include <linux/of_irq.h>
13 #include <linux/platform_device.h>
14 #include <linux/errno.h>
15 #include <linux/err.h>
16 #include <linux/export.h>
17 #include <linux/slab.h>
18 #include <asm/hw_irq.h>
19 #include <asm/ppc-pci.h>
20 #include <asm/mpic_msgr.h>
22 #define MPIC_MSGR_REGISTERS_PER_BLOCK 4
23 #define MPIC_MSGR_STRIDE 0x10
24 #define MPIC_MSGR_MER_OFFSET (0x100 / sizeof(u32))
28 static struct mpic_msgr **mpic_msgrs;
29 static unsigned int mpic_msgr_count;
30 static DEFINE_RAW_SPINLOCK(msgrs_lock);
32 static inline void _mpic_msgr_mer_write(struct mpic_msgr *msgr, u32 value)
34 out_be32(msgr->mer, value);
37 static inline u32 _mpic_msgr_mer_read(struct mpic_msgr *msgr)
39 return in_be32(msgr->mer);
42 static inline void _mpic_msgr_disable(struct mpic_msgr *msgr)
44 u32 mer = _mpic_msgr_mer_read(msgr);
46 _mpic_msgr_mer_write(msgr, mer & ~(1 << msgr->num));
49 struct mpic_msgr *mpic_msgr_get(unsigned int reg_num)
52 struct mpic_msgr *msgr;
54 /* Assume busy until proven otherwise. */
55 msgr = ERR_PTR(-EBUSY);
57 if (reg_num >= mpic_msgr_count)
58 return ERR_PTR(-ENODEV);
60 raw_spin_lock_irqsave(&msgrs_lock, flags);
61 msgr = mpic_msgrs[reg_num];
62 if (msgr->in_use == MSGR_FREE)
63 msgr->in_use = MSGR_INUSE;
64 raw_spin_unlock_irqrestore(&msgrs_lock, flags);
68 EXPORT_SYMBOL_GPL(mpic_msgr_get);
70 void mpic_msgr_put(struct mpic_msgr *msgr)
74 raw_spin_lock_irqsave(&msgr->lock, flags);
75 msgr->in_use = MSGR_FREE;
76 _mpic_msgr_disable(msgr);
77 raw_spin_unlock_irqrestore(&msgr->lock, flags);
79 EXPORT_SYMBOL_GPL(mpic_msgr_put);
81 void mpic_msgr_enable(struct mpic_msgr *msgr)
86 raw_spin_lock_irqsave(&msgr->lock, flags);
87 mer = _mpic_msgr_mer_read(msgr);
88 _mpic_msgr_mer_write(msgr, mer | (1 << msgr->num));
89 raw_spin_unlock_irqrestore(&msgr->lock, flags);
91 EXPORT_SYMBOL_GPL(mpic_msgr_enable);
93 void mpic_msgr_disable(struct mpic_msgr *msgr)
97 raw_spin_lock_irqsave(&msgr->lock, flags);
98 _mpic_msgr_disable(msgr);
99 raw_spin_unlock_irqrestore(&msgr->lock, flags);
101 EXPORT_SYMBOL_GPL(mpic_msgr_disable);
103 /* The following three functions are used to compute the order and number of
104 * the message register blocks. They are clearly very inefficient. However,
105 * they are called *only* a few times during device initialization.
107 static unsigned int mpic_msgr_number_of_blocks(void)
110 struct device_node *aliases;
113 aliases = of_find_node_by_name(NULL, "aliases");
119 snprintf(buf, sizeof(buf), "mpic-msgr-block%d", count);
120 if (!of_property_present(aliases, buf))
125 of_node_put(aliases);
131 static unsigned int mpic_msgr_number_of_registers(void)
133 return mpic_msgr_number_of_blocks() * MPIC_MSGR_REGISTERS_PER_BLOCK;
136 static int mpic_msgr_block_number(struct device_node *node)
138 struct device_node *aliases;
139 unsigned int index, number_of_blocks;
142 number_of_blocks = mpic_msgr_number_of_blocks();
143 aliases = of_find_node_by_name(NULL, "aliases");
147 for (index = 0; index < number_of_blocks; ++index) {
148 struct property *prop;
149 struct device_node *tn;
151 snprintf(buf, sizeof(buf), "mpic-msgr-block%d", index);
152 prop = of_find_property(aliases, buf, NULL);
153 tn = of_find_node_by_path(prop->value);
160 of_node_put(aliases);
162 return index == number_of_blocks ? -1 : index;
165 /* The probe function for a single message register block.
167 static int mpic_msgr_probe(struct platform_device *dev)
169 void __iomem *msgr_block_addr;
171 struct resource rsrc;
173 unsigned int irq_index;
174 struct device_node *np = dev->dev.of_node;
175 unsigned int receive_mask;
176 const unsigned int *prop;
179 dev_err(&dev->dev, "Device OF-Node is NULL");
183 /* Allocate the message register array upon the first device
187 mpic_msgr_count = mpic_msgr_number_of_registers();
188 dev_info(&dev->dev, "Found %d message registers\n",
191 mpic_msgrs = kcalloc(mpic_msgr_count, sizeof(*mpic_msgrs),
195 "No memory for message register blocks\n");
199 dev_info(&dev->dev, "Of-device full name %pOF\n", np);
201 /* IO map the message register block. */
202 of_address_to_resource(np, 0, &rsrc);
203 msgr_block_addr = devm_ioremap(&dev->dev, rsrc.start, resource_size(&rsrc));
204 if (!msgr_block_addr) {
205 dev_err(&dev->dev, "Failed to iomap MPIC message registers");
209 /* Ensure the block has a defined order. */
210 block_number = mpic_msgr_block_number(np);
211 if (block_number < 0) {
213 "Failed to find message register block alias\n");
216 dev_info(&dev->dev, "Setting up message register block %d\n",
219 /* Grab the receive mask which specifies what registers can receive
222 prop = of_get_property(np, "mpic-msgr-receive-mask", NULL);
223 receive_mask = (prop) ? *prop : 0xF;
225 /* Build up the appropriate message register data structures. */
226 for (i = 0, irq_index = 0; i < MPIC_MSGR_REGISTERS_PER_BLOCK; ++i) {
227 struct mpic_msgr *msgr;
228 unsigned int reg_number;
230 msgr = kzalloc(sizeof(struct mpic_msgr), GFP_KERNEL);
232 dev_err(&dev->dev, "No memory for message register\n");
236 reg_number = block_number * MPIC_MSGR_REGISTERS_PER_BLOCK + i;
237 msgr->base = msgr_block_addr + i * MPIC_MSGR_STRIDE;
238 msgr->mer = msgr->base + MPIC_MSGR_MER_OFFSET;
239 msgr->in_use = MSGR_FREE;
241 raw_spin_lock_init(&msgr->lock);
243 if (receive_mask & (1 << i)) {
244 msgr->irq = irq_of_parse_and_map(np, irq_index);
247 "Missing interrupt specifier");
256 mpic_msgrs[reg_number] = msgr;
257 mpic_msgr_disable(msgr);
258 dev_info(&dev->dev, "Register %d initialized: irq %d\n",
259 reg_number, msgr->irq);
266 static const struct of_device_id mpic_msgr_ids[] = {
268 .compatible = "fsl,mpic-v3.1-msgr",
274 static struct platform_driver mpic_msgr_driver = {
277 .of_match_table = mpic_msgr_ids,
279 .probe = mpic_msgr_probe,
282 static __init int mpic_msgr_init(void)
284 return platform_driver_register(&mpic_msgr_driver);
286 subsys_initcall(mpic_msgr_init);