1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * External Interrupt Controller on Spider South Bridge
4 *
5 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
6 *
7 * Author: Arnd Bergmann <arndb@de.ibm.com>
8 */
9
10 #include <linux/interrupt.h>
11 #include <linux/irq.h>
12 #include <linux/ioport.h>
13 #include <linux/of_address.h>
14 #include <linux/of_irq.h>
15 #include <linux/pgtable.h>
16
17 #include <asm/io.h>
18
19 #include "interrupt.h"
20
21 /* register layout taken from Spider spec, table 7.4-4 */
22 enum {
23 TIR_DEN = 0x004, /* Detection Enable Register */
24 TIR_MSK = 0x084, /* Mask Level Register */
25 TIR_EDC = 0x0c0, /* Edge Detection Clear Register */
26 TIR_PNDA = 0x100, /* Pending Register A */
27 TIR_PNDB = 0x104, /* Pending Register B */
28 TIR_CS = 0x144, /* Current Status Register */
29 TIR_LCSA = 0x150, /* Level Current Status Register A */
30 TIR_LCSB = 0x154, /* Level Current Status Register B */
31 TIR_LCSC = 0x158, /* Level Current Status Register C */
32 TIR_LCSD = 0x15c, /* Level Current Status Register D */
33 TIR_CFGA = 0x200, /* Setting Register A0 */
34 TIR_CFGB = 0x204, /* Setting Register B0 */
35 /* 0x208 ... 0x3ff Setting Register An/Bn */
36 TIR_PPNDA = 0x400, /* Packet Pending Register A */
37 TIR_PPNDB = 0x404, /* Packet Pending Register B */
38 TIR_PIERA = 0x408, /* Packet Output Error Register A */
39 TIR_PIERB = 0x40c, /* Packet Output Error Register B */
40 TIR_PIEN = 0x444, /* Packet Output Enable Register */
41 TIR_PIPND = 0x454, /* Packet Output Pending Register */
42 TIRDID = 0x484, /* Spider Device ID Register */
43 REISTIM = 0x500, /* Reissue Command Timeout Time Setting */
44 REISTIMEN = 0x504, /* Reissue Command Timeout Setting */
45 REISWAITEN = 0x508, /* Reissue Wait Control*/
46 };
47
48 #define SPIDER_CHIP_COUNT 4
49 #define SPIDER_SRC_COUNT 64
50 #define SPIDER_IRQ_INVALID 63
51
52 struct spider_pic {
53 struct irq_domain *host;
54 void __iomem *regs;
55 unsigned int node_id;
56 };
57 static struct spider_pic spider_pics[SPIDER_CHIP_COUNT];
58
59 static struct spider_pic *spider_irq_data_to_pic(struct irq_data *d)
60 {
61 return irq_data_get_irq_chip_data(d);
62 }
63
64 static void __iomem *spider_get_irq_config(struct spider_pic *pic,
65 unsigned int src)
66 {
67 return pic->regs + TIR_CFGA + 8 * src;
68 }
69
70 static void spider_unmask_irq(struct irq_data *d)
71 {
72 struct spider_pic *pic = spider_irq_data_to_pic(d);
73 void __iomem *cfg = spider_get_irq_config(pic, irqd_to_hwirq(d));
74
75 out_be32(cfg, in_be32(cfg) | 0x30000000u);
76 }
77
78 static void spider_mask_irq(struct irq_data *d)
79 {
80 struct spider_pic *pic = spider_irq_data_to_pic(d);
81 void __iomem *cfg = spider_get_irq_config(pic, irqd_to_hwirq(d));
82
83 out_be32(cfg, in_be32(cfg) & ~0x30000000u);
84 }
85
86 static void spider_ack_irq(struct irq_data *d)
87 {
88 struct spider_pic *pic = spider_irq_data_to_pic(d);
89 unsigned int src = irqd_to_hwirq(d);
90
91 /* Reset edge detection logic if necessary
92 */
93 if (irqd_is_level_type(d))
94 return;
95
96 /* Only interrupts 47 to 50 can be set to edge */
97 if (src < 47 || src > 50)
98 return;
99
100 /* Perform the clear of the edge logic */
101 out_be32(pic->regs + TIR_EDC, 0x100 | (src & 0xf));
102 }
103
104 static int spider_set_irq_type(struct irq_data *d, unsigned int type)
105 {
106 unsigned int sense = type & IRQ_TYPE_SENSE_MASK;
107 struct spider_pic *pic = spider_irq_data_to_pic(d);
108 unsigned int hw = irqd_to_hwirq(d);
109 void __iomem *cfg = spider_get_irq_config(pic, hw);
110 u32 old_mask;
111 u32 ic;
112
113 /* Note that only level high is supported for most interrupts */
114 if (sense != IRQ_TYPE_NONE && sense != IRQ_TYPE_LEVEL_HIGH &&
115 (hw < 47 || hw > 50))
116 return -EINVAL;
117
118 /* Decode sense type */
119 switch(sense) {
120 case IRQ_TYPE_EDGE_RISING:
121 ic = 0x3;
122 break;
123 case IRQ_TYPE_EDGE_FALLING:
124 ic = 0x2;
125 break;
126 case IRQ_TYPE_LEVEL_LOW:
127 ic = 0x0;
128 break;
129 case IRQ_TYPE_LEVEL_HIGH:
130 case IRQ_TYPE_NONE:
131 ic = 0x1;
132 break;
133 default:
134 return -EINVAL;
135 }
136
137 /* Configure the source. One gross hack that was there before and
138 * that I've kept around is the priority to the BE which I set to
139 * be the same as the interrupt source number. I don't know whether
140 * that's supposed to make any kind of sense however, we'll have to
141 * decide that, but for now, I'm not changing the behaviour.
142 */
143 old_mask = in_be32(cfg) & 0x30000000u;
144 out_be32(cfg, old_mask | (ic << 24) | (0x7 << 16) |
145 (pic->node_id << 4) | 0xe);
146 out_be32(cfg + 4, (0x2 << 16) | (hw & 0xff));
147
148 return 0;
149 }
150
151 static struct irq_chip spider_pic = {
152 .name = "SPIDER",
153 .irq_unmask = spider_unmask_irq,
154 .irq_mask = spider_mask_irq,
155 .irq_ack = spider_ack_irq,
156 .irq_set_type = spider_set_irq_type,
157 };
158
159 static int spider_host_map(struct irq_domain *h, unsigned int virq,
160 irq_hw_number_t hw)
161 {
162 irq_set_chip_data(virq, h->host_data);
163 irq_set_chip_and_handler(virq, &spider_pic, handle_level_irq);
164
165 /* Set default irq type */
166 irq_set_irq_type(virq, IRQ_TYPE_NONE);
167
168 return 0;
169 }
170
171 static int spider_host_xlate(struct irq_domain *h, struct device_node *ct,
172 const u32 *intspec, unsigned int intsize,
173 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
174
175 {
176 /* Spider interrupts have 2 cells, first is the interrupt source,
177 * second, well, I don't know for sure yet ... We mask the top bits
178 * because old device-trees encode a node number in there
179 */
180 *out_hwirq = intspec[0] & 0x3f;
181 *out_flags = IRQ_TYPE_LEVEL_HIGH;
182 return 0;
183 }
184
185 static const struct irq_domain_ops spider_host_ops = {
186 .map = spider_host_map,
187 .xlate = spider_host_xlate,
188 };
189
190 static void spider_irq_cascade(struct irq_desc *desc)
191 {
192 struct irq_chip *chip = irq_desc_get_chip(desc);
193 struct spider_pic *pic = irq_desc_get_handler_data(desc);
194 unsigned int cs;
195
196 cs = in_be32(pic->regs + TIR_CS) >> 24;
197 if (cs != SPIDER_IRQ_INVALID)
198 generic_handle_domain_irq(pic->host, cs);
199
200 chip->irq_eoi(&desc->irq_data);
201 }
202
203 /* For hooking up the cascade we have a problem. Our device-tree is
204 * crap and we don't know on which BE iic interrupt we are hooked on at
205 * least not the "standard" way. We can reconstitute it based on two
206 * informations though: which BE node we are connected to and whether
207 * we are connected to IOIF0 or IOIF1. Right now, we really only care
208 * about the IBM cell blade and we know that its firmware gives us an
209 * interrupt-map property which is pretty strange.
210 */
211 static unsigned int __init spider_find_cascade_and_node(struct spider_pic *pic)
212 {
213 unsigned int virq;
214 const u32 *imap, *tmp;
215 int imaplen, intsize, unit;
216 struct device_node *iic;
217 struct device_node *of_node;
218
219 of_node = irq_domain_get_of_node(pic->host);
220
221 /* First, we check whether we have a real "interrupts" in the device
222 * tree in case the device-tree is ever fixed
223 */
224 virq = irq_of_parse_and_map(of_node, 0);
225 if (virq)
226 return virq;
227
228 /* Now do the horrible hacks */
229 tmp = of_get_property(of_node, "#interrupt-cells", NULL);
230 if (tmp == NULL)
231 return 0;
232 intsize = *tmp;
233 imap = of_get_property(of_node, "interrupt-map", &imaplen);
234 if (imap == NULL || imaplen < (intsize + 1))
235 return 0;
236 iic = of_find_node_by_phandle(imap[intsize]);
237 if (iic == NULL)
238 return 0;
239 imap += intsize + 1;
240 tmp = of_get_property(iic, "#interrupt-cells", NULL);
241 if (tmp == NULL) {
242 of_node_put(iic);
243 return 0;
244 }
245 intsize = *tmp;
246 /* Assume unit is last entry of interrupt specifier */
247 unit = imap[intsize - 1];
248 /* Ok, we have a unit, now let's try to get the node */
249 tmp = of_get_property(iic, "ibm,interrupt-server-ranges", NULL);
250 if (tmp == NULL) {
251 of_node_put(iic);
252 return 0;
253 }
254 /* ugly as hell but works for now */
255 pic->node_id = (*tmp) >> 1;
256 of_node_put(iic);
257
258 /* Ok, now let's get cracking. You may ask me why I just didn't match
259 * the iic host from the iic OF node, but that way I'm still compatible
260 * with really really old old firmwares for which we don't have a node
261 */
262 /* Manufacture an IIC interrupt number of class 2 */
263 virq = irq_create_mapping(NULL,
264 (pic->node_id << IIC_IRQ_NODE_SHIFT) |
265 (2 << IIC_IRQ_CLASS_SHIFT) |
266 unit);
267 if (!virq)
268 printk(KERN_ERR "spider_pic: failed to map cascade !");
269 return virq;
270 }
271
272
273 static void __init spider_init_one(struct device_node *of_node, int chip,
274 unsigned long addr)
275 {
276 struct spider_pic *pic = &spider_pics[chip];
277 int i, virq;
278
279 /* Map registers */
280 pic->regs = ioremap(addr, 0x1000);
281 if (pic->regs == NULL)
282 panic("spider_pic: can't map registers !");
283
284 /* Allocate a host */
285 pic->host = irq_domain_add_linear(of_node, SPIDER_SRC_COUNT,
286 &spider_host_ops, pic);
287 if (pic->host == NULL)
288 panic("spider_pic: can't allocate irq host !");
289
290 /* Go through all sources and disable them */
291 for (i = 0; i < SPIDER_SRC_COUNT; i++) {
292 void __iomem *cfg = pic->regs + TIR_CFGA + 8 * i;
293 out_be32(cfg, in_be32(cfg) & ~0x30000000u);
294 }
295
296 /* do not mask any interrupts because of level */
297 out_be32(pic->regs + TIR_MSK, 0x0);
298
299 /* enable interrupt packets to be output */
300 out_be32(pic->regs + TIR_PIEN, in_be32(pic->regs + TIR_PIEN) | 0x1);
301
302 /* Hook up the cascade interrupt to the iic and nodeid */
303 virq = spider_find_cascade_and_node(pic);
304 if (!virq)
305 return;
306 irq_set_handler_data(virq, pic);
307 irq_set_chained_handler(virq, spider_irq_cascade);
308
309 printk(KERN_INFO "spider_pic: node %d, addr: 0x%lx %pOF\n",
310 pic->node_id, addr, of_node);
311
312 /* Enable the interrupt detection enable bit. Do this last! */
313 out_be32(pic->regs + TIR_DEN, in_be32(pic->regs + TIR_DEN) | 0x1);
314 }
315
316 void __init spider_init_IRQ(void)
317 {
318 struct resource r;
319 struct device_node *dn;
320 int chip = 0;
321
322 /* XXX node numbers are totally bogus. We _hope_ we get the device
323 * nodes in the right order here but that's definitely not guaranteed,
324 * we need to get the node from the device tree instead.
325 * There is currently no proper property for it (but our whole
326 * device-tree is bogus anyway) so all we can do is pray or maybe test
327 * the address and deduce the node-id
328 */
329 for_each_node_by_name(dn, "interrupt-controller") {
330 if (of_device_is_compatible(dn, "CBEA,platform-spider-pic")) {
331 if (of_address_to_resource(dn, 0, &r)) {
332 printk(KERN_WARNING "spider-pic: Failed\n");
333 continue;
334 }
335 } else if (of_device_is_compatible(dn, "sti,platform-spider-pic")
336 && (chip < 2)) {
337 static long hard_coded_pics[] =
338 { 0x24000008000ul, 0x34000008000ul};
339 r.start = hard_coded_pics[chip];
340 } else
341 continue;
342 spider_init_one(dn, chip++, r.start);
343 }
344 }
345
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.