1 /*
2  * Interrupt handling for Marvell mv64360/mv64460 host bridges (Discovery)
3  *
4  * Author: Dale Farnsworth <dale@farnsworth.org>
5  *
6  * 2007 (c) MontaVista, Software, Inc.  This file is licensed under
7  * the terms of the GNU General Public License version 2.  This program
8  * is licensed "as is" without any warranty of any kind, whether express
9  * or implied.
10  */
11 
12 #include <linux/stddef.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/irq.h>
16 #include <linux/interrupt.h>
17 #include <linux/spinlock.h>
18 
19 #include <asm/byteorder.h>
20 #include <asm/io.h>
21 #include <asm/prom.h>
22 #include <asm/irq.h>
23 
24 #include "mv64x60.h"
25 
26 /* Interrupt Controller Interface Registers */
27 #define MV64X60_IC_MAIN_CAUSE_LO	0x0004
28 #define MV64X60_IC_MAIN_CAUSE_HI	0x000c
29 #define MV64X60_IC_CPU0_INTR_MASK_LO	0x0014
30 #define MV64X60_IC_CPU0_INTR_MASK_HI	0x001c
31 #define MV64X60_IC_CPU0_SELECT_CAUSE	0x0024
32 
33 #define MV64X60_HIGH_GPP_GROUPS		0x0f000000
34 #define MV64X60_SELECT_CAUSE_HIGH	0x40000000
35 
36 /* General Purpose Pins Controller Interface Registers */
37 #define MV64x60_GPP_INTR_CAUSE		0x0008
38 #define MV64x60_GPP_INTR_MASK		0x000c
39 
40 #define MV64x60_LEVEL1_LOW		0
41 #define MV64x60_LEVEL1_HIGH		1
42 #define MV64x60_LEVEL1_GPP		2
43 
44 #define MV64x60_LEVEL1_MASK		0x00000060
45 #define MV64x60_LEVEL1_OFFSET		5
46 
47 #define MV64x60_LEVEL2_MASK		0x0000001f
48 
49 #define MV64x60_NUM_IRQS		96
50 
51 static DEFINE_SPINLOCK(mv64x60_lock);
52 
53 static void __iomem *mv64x60_irq_reg_base;
54 static void __iomem *mv64x60_gpp_reg_base;
55 
56 /*
57  * Interrupt Controller Handling
58  *
59  * The interrupt controller handles three groups of interrupts:
60  *   main low:	IRQ0-IRQ31
61  *   main high:	IRQ32-IRQ63
62  *   gpp:	IRQ64-IRQ95
63  *
64  * This code handles interrupts in two levels.  Level 1 selects the
65  * interrupt group, and level 2 selects an IRQ within that group.
66  * Each group has its own irq_chip structure.
67  */
68 
69 static u32 mv64x60_cached_low_mask;
70 static u32 mv64x60_cached_high_mask = MV64X60_HIGH_GPP_GROUPS;
71 static u32 mv64x60_cached_gpp_mask;
72 
73 static struct irq_domain *mv64x60_irq_host;
74 
75 /*
76  * mv64x60_chip_low functions
77  */
78 
mv64x60_mask_low(struct irq_data * d)79 static void mv64x60_mask_low(struct irq_data *d)
80 {
81 	int level2 = irqd_to_hwirq(d) & MV64x60_LEVEL2_MASK;
82 	unsigned long flags;
83 
84 	spin_lock_irqsave(&mv64x60_lock, flags);
85 	mv64x60_cached_low_mask &= ~(1 << level2);
86 	out_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_LO,
87 		 mv64x60_cached_low_mask);
88 	spin_unlock_irqrestore(&mv64x60_lock, flags);
89 	(void)in_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_LO);
90 }
91 
mv64x60_unmask_low(struct irq_data * d)92 static void mv64x60_unmask_low(struct irq_data *d)
93 {
94 	int level2 = irqd_to_hwirq(d) & MV64x60_LEVEL2_MASK;
95 	unsigned long flags;
96 
97 	spin_lock_irqsave(&mv64x60_lock, flags);
98 	mv64x60_cached_low_mask |= 1 << level2;
99 	out_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_LO,
100 		 mv64x60_cached_low_mask);
101 	spin_unlock_irqrestore(&mv64x60_lock, flags);
102 	(void)in_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_LO);
103 }
104 
105 static struct irq_chip mv64x60_chip_low = {
106 	.name		= "mv64x60_low",
107 	.irq_mask	= mv64x60_mask_low,
108 	.irq_mask_ack	= mv64x60_mask_low,
109 	.irq_unmask	= mv64x60_unmask_low,
110 };
111 
112 /*
113  * mv64x60_chip_high functions
114  */
115 
mv64x60_mask_high(struct irq_data * d)116 static void mv64x60_mask_high(struct irq_data *d)
117 {
118 	int level2 = irqd_to_hwirq(d) & MV64x60_LEVEL2_MASK;
119 	unsigned long flags;
120 
121 	spin_lock_irqsave(&mv64x60_lock, flags);
122 	mv64x60_cached_high_mask &= ~(1 << level2);
123 	out_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_HI,
124 		 mv64x60_cached_high_mask);
125 	spin_unlock_irqrestore(&mv64x60_lock, flags);
126 	(void)in_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_HI);
127 }
128 
mv64x60_unmask_high(struct irq_data * d)129 static void mv64x60_unmask_high(struct irq_data *d)
130 {
131 	int level2 = irqd_to_hwirq(d) & MV64x60_LEVEL2_MASK;
132 	unsigned long flags;
133 
134 	spin_lock_irqsave(&mv64x60_lock, flags);
135 	mv64x60_cached_high_mask |= 1 << level2;
136 	out_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_HI,
137 		 mv64x60_cached_high_mask);
138 	spin_unlock_irqrestore(&mv64x60_lock, flags);
139 	(void)in_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_HI);
140 }
141 
142 static struct irq_chip mv64x60_chip_high = {
143 	.name		= "mv64x60_high",
144 	.irq_mask	= mv64x60_mask_high,
145 	.irq_mask_ack	= mv64x60_mask_high,
146 	.irq_unmask	= mv64x60_unmask_high,
147 };
148 
149 /*
150  * mv64x60_chip_gpp functions
151  */
152 
mv64x60_mask_gpp(struct irq_data * d)153 static void mv64x60_mask_gpp(struct irq_data *d)
154 {
155 	int level2 = irqd_to_hwirq(d) & MV64x60_LEVEL2_MASK;
156 	unsigned long flags;
157 
158 	spin_lock_irqsave(&mv64x60_lock, flags);
159 	mv64x60_cached_gpp_mask &= ~(1 << level2);
160 	out_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_MASK,
161 		 mv64x60_cached_gpp_mask);
162 	spin_unlock_irqrestore(&mv64x60_lock, flags);
163 	(void)in_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_MASK);
164 }
165 
mv64x60_mask_ack_gpp(struct irq_data * d)166 static void mv64x60_mask_ack_gpp(struct irq_data *d)
167 {
168 	int level2 = irqd_to_hwirq(d) & MV64x60_LEVEL2_MASK;
169 	unsigned long flags;
170 
171 	spin_lock_irqsave(&mv64x60_lock, flags);
172 	mv64x60_cached_gpp_mask &= ~(1 << level2);
173 	out_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_MASK,
174 		 mv64x60_cached_gpp_mask);
175 	out_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_CAUSE,
176 		 ~(1 << level2));
177 	spin_unlock_irqrestore(&mv64x60_lock, flags);
178 	(void)in_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_CAUSE);
179 }
180 
mv64x60_unmask_gpp(struct irq_data * d)181 static void mv64x60_unmask_gpp(struct irq_data *d)
182 {
183 	int level2 = irqd_to_hwirq(d) & MV64x60_LEVEL2_MASK;
184 	unsigned long flags;
185 
186 	spin_lock_irqsave(&mv64x60_lock, flags);
187 	mv64x60_cached_gpp_mask |= 1 << level2;
188 	out_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_MASK,
189 		 mv64x60_cached_gpp_mask);
190 	spin_unlock_irqrestore(&mv64x60_lock, flags);
191 	(void)in_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_MASK);
192 }
193 
194 static struct irq_chip mv64x60_chip_gpp = {
195 	.name		= "mv64x60_gpp",
196 	.irq_mask	= mv64x60_mask_gpp,
197 	.irq_mask_ack	= mv64x60_mask_ack_gpp,
198 	.irq_unmask	= mv64x60_unmask_gpp,
199 };
200 
201 /*
202  * mv64x60_host_ops functions
203  */
204 
205 static struct irq_chip *mv64x60_chips[] = {
206 	[MV64x60_LEVEL1_LOW]  = &mv64x60_chip_low,
207 	[MV64x60_LEVEL1_HIGH] = &mv64x60_chip_high,
208 	[MV64x60_LEVEL1_GPP]  = &mv64x60_chip_gpp,
209 };
210 
mv64x60_host_map(struct irq_domain * h,unsigned int virq,irq_hw_number_t hwirq)211 static int mv64x60_host_map(struct irq_domain *h, unsigned int virq,
212 			  irq_hw_number_t hwirq)
213 {
214 	int level1;
215 
216 	irq_set_status_flags(virq, IRQ_LEVEL);
217 
218 	level1 = (hwirq & MV64x60_LEVEL1_MASK) >> MV64x60_LEVEL1_OFFSET;
219 	BUG_ON(level1 > MV64x60_LEVEL1_GPP);
220 	irq_set_chip_and_handler(virq, mv64x60_chips[level1],
221 				 handle_level_irq);
222 
223 	return 0;
224 }
225 
226 static struct irq_domain_ops mv64x60_host_ops = {
227 	.map   = mv64x60_host_map,
228 };
229 
230 /*
231  * Global functions
232  */
233 
mv64x60_init_irq(void)234 void __init mv64x60_init_irq(void)
235 {
236 	struct device_node *np;
237 	phys_addr_t paddr;
238 	unsigned int size;
239 	const unsigned int *reg;
240 	unsigned long flags;
241 
242 	np = of_find_compatible_node(NULL, NULL, "marvell,mv64360-gpp");
243 	reg = of_get_property(np, "reg", &size);
244 	paddr = of_translate_address(np, reg);
245 	mv64x60_gpp_reg_base = ioremap(paddr, reg[1]);
246 	of_node_put(np);
247 
248 	np = of_find_compatible_node(NULL, NULL, "marvell,mv64360-pic");
249 	reg = of_get_property(np, "reg", &size);
250 	paddr = of_translate_address(np, reg);
251 	mv64x60_irq_reg_base = ioremap(paddr, reg[1]);
252 
253 	mv64x60_irq_host = irq_domain_add_linear(np, MV64x60_NUM_IRQS,
254 					  &mv64x60_host_ops, NULL);
255 
256 	spin_lock_irqsave(&mv64x60_lock, flags);
257 	out_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_MASK,
258 		 mv64x60_cached_gpp_mask);
259 	out_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_LO,
260 		 mv64x60_cached_low_mask);
261 	out_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_INTR_MASK_HI,
262 		 mv64x60_cached_high_mask);
263 
264 	out_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_CAUSE, 0);
265 	out_le32(mv64x60_irq_reg_base + MV64X60_IC_MAIN_CAUSE_LO, 0);
266 	out_le32(mv64x60_irq_reg_base + MV64X60_IC_MAIN_CAUSE_HI, 0);
267 	spin_unlock_irqrestore(&mv64x60_lock, flags);
268 }
269 
mv64x60_get_irq(void)270 unsigned int mv64x60_get_irq(void)
271 {
272 	u32 cause;
273 	int level1;
274 	irq_hw_number_t hwirq;
275 	int virq = NO_IRQ;
276 
277 	cause = in_le32(mv64x60_irq_reg_base + MV64X60_IC_CPU0_SELECT_CAUSE);
278 	if (cause & MV64X60_SELECT_CAUSE_HIGH) {
279 		cause &= mv64x60_cached_high_mask;
280 		level1 = MV64x60_LEVEL1_HIGH;
281 		if (cause & MV64X60_HIGH_GPP_GROUPS) {
282 			cause = in_le32(mv64x60_gpp_reg_base +
283 					MV64x60_GPP_INTR_CAUSE);
284 			cause &= mv64x60_cached_gpp_mask;
285 			level1 = MV64x60_LEVEL1_GPP;
286 		}
287 	} else {
288 		cause &= mv64x60_cached_low_mask;
289 		level1 = MV64x60_LEVEL1_LOW;
290 	}
291 	if (cause) {
292 		hwirq = (level1 << MV64x60_LEVEL1_OFFSET) | __ilog2(cause);
293 		virq = irq_linear_revmap(mv64x60_irq_host, hwirq);
294 	}
295 
296 	return virq;
297 }
298