2 * Copyright 2011-2012, Meador Inge, Mentor Graphics Corporation.
4 * Some ideas based on un-pushed work done by Vivek Mahajan, Jason Jin, and
5 * Mingkai Hu from Freescale Semiconductor, Inc.
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; version 2 of the
14 #include <linux/list.h>
15 #include <linux/of_platform.h>
16 #include <linux/errno.h>
17 #include <linux/err.h>
18 #include <linux/export.h>
19 #include <linux/slab.h>
21 #include <asm/hw_irq.h>
22 #include <asm/ppc-pci.h>
23 #include <asm/mpic_msgr.h>
25 #define MPIC_MSGR_REGISTERS_PER_BLOCK 4
26 #define MPIC_MSGR_STRIDE 0x10
27 #define MPIC_MSGR_MER_OFFSET 0x100
31 static struct mpic_msgr
**mpic_msgrs
;
32 static unsigned int mpic_msgr_count
;
33 static DEFINE_RAW_SPINLOCK(msgrs_lock
);
35 static inline void _mpic_msgr_mer_write(struct mpic_msgr
*msgr
, u32 value
)
37 out_be32(msgr
->mer
, value
);
40 static inline u32
_mpic_msgr_mer_read(struct mpic_msgr
*msgr
)
42 return in_be32(msgr
->mer
);
45 static inline void _mpic_msgr_disable(struct mpic_msgr
*msgr
)
47 u32 mer
= _mpic_msgr_mer_read(msgr
);
49 _mpic_msgr_mer_write(msgr
, mer
& ~(1 << msgr
->num
));
52 struct mpic_msgr
*mpic_msgr_get(unsigned int reg_num
)
55 struct mpic_msgr
*msgr
;
57 /* Assume busy until proven otherwise. */
58 msgr
= ERR_PTR(-EBUSY
);
60 if (reg_num
>= mpic_msgr_count
)
61 return ERR_PTR(-ENODEV
);
63 raw_spin_lock_irqsave(&msgrs_lock
, flags
);
64 msgr
= mpic_msgrs
[reg_num
];
65 if (msgr
->in_use
== MSGR_FREE
)
66 msgr
->in_use
= MSGR_INUSE
;
67 raw_spin_unlock_irqrestore(&msgrs_lock
, flags
);
71 EXPORT_SYMBOL_GPL(mpic_msgr_get
);
73 void mpic_msgr_put(struct mpic_msgr
*msgr
)
77 raw_spin_lock_irqsave(&msgr
->lock
, flags
);
78 msgr
->in_use
= MSGR_FREE
;
79 _mpic_msgr_disable(msgr
);
80 raw_spin_unlock_irqrestore(&msgr
->lock
, flags
);
82 EXPORT_SYMBOL_GPL(mpic_msgr_put
);
84 void mpic_msgr_enable(struct mpic_msgr
*msgr
)
89 raw_spin_lock_irqsave(&msgr
->lock
, flags
);
90 mer
= _mpic_msgr_mer_read(msgr
);
91 _mpic_msgr_mer_write(msgr
, mer
| (1 << msgr
->num
));
92 raw_spin_unlock_irqrestore(&msgr
->lock
, flags
);
94 EXPORT_SYMBOL_GPL(mpic_msgr_enable
);
96 void mpic_msgr_disable(struct mpic_msgr
*msgr
)
100 raw_spin_lock_irqsave(&msgr
->lock
, flags
);
101 _mpic_msgr_disable(msgr
);
102 raw_spin_unlock_irqrestore(&msgr
->lock
, flags
);
104 EXPORT_SYMBOL_GPL(mpic_msgr_disable
);
106 /* The following three functions are used to compute the order and number of
107 * the message register blocks. They are clearly very inefficent. However,
108 * they are called *only* a few times during device initialization.
110 static unsigned int mpic_msgr_number_of_blocks(void)
113 struct device_node
*aliases
;
116 aliases
= of_find_node_by_name(NULL
, "aliases");
122 snprintf(buf
, sizeof(buf
), "mpic-msgr-block%d", count
);
123 if (!of_find_property(aliases
, buf
, NULL
))
133 static unsigned int mpic_msgr_number_of_registers(void)
135 return mpic_msgr_number_of_blocks() * MPIC_MSGR_REGISTERS_PER_BLOCK
;
138 static int mpic_msgr_block_number(struct device_node
*node
)
140 struct device_node
*aliases
;
141 unsigned int index
, number_of_blocks
;
144 number_of_blocks
= mpic_msgr_number_of_blocks();
145 aliases
= of_find_node_by_name(NULL
, "aliases");
149 for (index
= 0; index
< number_of_blocks
; ++index
) {
150 struct property
*prop
;
152 snprintf(buf
, sizeof(buf
), "mpic-msgr-block%d", index
);
153 prop
= of_find_property(aliases
, buf
, NULL
);
154 if (node
== of_find_node_by_path(prop
->value
))
158 return index
== number_of_blocks
? -1 : index
;
161 /* The probe function for a single message register block.
163 static int mpic_msgr_probe(struct platform_device
*dev
)
165 void __iomem
*msgr_block_addr
;
167 struct resource rsrc
;
169 unsigned int irq_index
;
170 struct device_node
*np
= dev
->dev
.of_node
;
171 unsigned int receive_mask
;
172 const unsigned int *prop
;
175 dev_err(&dev
->dev
, "Device OF-Node is NULL");
179 /* Allocate the message register array upon the first device
183 mpic_msgr_count
= mpic_msgr_number_of_registers();
184 dev_info(&dev
->dev
, "Found %d message registers\n",
187 mpic_msgrs
= kzalloc(sizeof(struct mpic_msgr
) * mpic_msgr_count
,
191 "No memory for message register blocks\n");
195 dev_info(&dev
->dev
, "Of-device full name %s\n", np
->full_name
);
197 /* IO map the message register block. */
198 of_address_to_resource(np
, 0, &rsrc
);
199 msgr_block_addr
= ioremap(rsrc
.start
, rsrc
.end
- rsrc
.start
);
200 if (!msgr_block_addr
) {
201 dev_err(&dev
->dev
, "Failed to iomap MPIC message registers");
205 /* Ensure the block has a defined order. */
206 block_number
= mpic_msgr_block_number(np
);
207 if (block_number
< 0) {
209 "Failed to find message register block alias\n");
212 dev_info(&dev
->dev
, "Setting up message register block %d\n",
215 /* Grab the receive mask which specifies what registers can receive
218 prop
= of_get_property(np
, "mpic-msgr-receive-mask", NULL
);
219 receive_mask
= (prop
) ? *prop
: 0xF;
221 /* Build up the appropriate message register data structures. */
222 for (i
= 0, irq_index
= 0; i
< MPIC_MSGR_REGISTERS_PER_BLOCK
; ++i
) {
223 struct mpic_msgr
*msgr
;
224 unsigned int reg_number
;
226 msgr
= kzalloc(sizeof(struct mpic_msgr
), GFP_KERNEL
);
228 dev_err(&dev
->dev
, "No memory for message register\n");
232 reg_number
= block_number
* MPIC_MSGR_REGISTERS_PER_BLOCK
+ i
;
233 msgr
->base
= msgr_block_addr
+ i
* MPIC_MSGR_STRIDE
;
234 msgr
->mer
= (u32
*)((u8
*)msgr
->base
+ MPIC_MSGR_MER_OFFSET
);
235 msgr
->in_use
= MSGR_FREE
;
237 raw_spin_lock_init(&msgr
->lock
);
239 if (receive_mask
& (1 << i
)) {
240 msgr
->irq
= irq_of_parse_and_map(np
, irq_index
);
241 if (msgr
->irq
== NO_IRQ
) {
243 "Missing interrupt specifier");
252 mpic_msgrs
[reg_number
] = msgr
;
253 mpic_msgr_disable(msgr
);
254 dev_info(&dev
->dev
, "Register %d initialized: irq %d\n",
255 reg_number
, msgr
->irq
);
262 static const struct of_device_id mpic_msgr_ids
[] = {
264 .compatible
= "fsl,mpic-v3.1-msgr",
270 static struct platform_driver mpic_msgr_driver
= {
273 .owner
= THIS_MODULE
,
274 .of_match_table
= mpic_msgr_ids
,
276 .probe
= mpic_msgr_probe
,
279 static __init
int mpic_msgr_init(void)
281 return platform_driver_register(&mpic_msgr_driver
);
283 subsys_initcall(mpic_msgr_init
);