xref: /linux/arch/powerpc/sysdev/cpm2_pic.c (revision b0148a98ec5151fec82064d95f11eb9efbc628ea)
1 /*
2  * Platform information definitions.
3  *
4  * Copied from arch/ppc/syslib/cpm2_pic.c with minor subsequent updates
5  * to make in work in arch/powerpc/. Original (c) belongs to Dan Malek.
6  *
7  * Author:  Vitaly Bordug <vbordug@ru.mvista.com>
8  *
9  * 1999-2001 (c) Dan Malek <dan@embeddedalley.com>
10  * 2006 (c) MontaVista Software, Inc.
11  *
12  * This file is licensed under the terms of the GNU General Public License
13  * version 2. This program is licensed "as is" without any warranty of any
14  * kind, whether express or implied.
15  */
16 
17 /* The CPM2 internal interrupt controller.  It is usually
18  * the only interrupt controller.
19  * There are two 32-bit registers (high/low) for up to 64
20  * possible interrupts.
21  *
22  * Now, the fun starts.....Interrupt Numbers DO NOT MAP
23  * in a simple arithmetic fashion to mask or pending registers.
24  * That is, interrupt 4 does not map to bit position 4.
25  * We create two tables, indexed by vector number, to indicate
26  * which register to use and which bit in the register to use.
27  */
28 
29 #include <linux/stddef.h>
30 #include <linux/init.h>
31 #include <linux/sched.h>
32 #include <linux/signal.h>
33 #include <linux/irq.h>
34 
35 #include <asm/immap_cpm2.h>
36 #include <asm/mpc8260.h>
37 #include <asm/io.h>
38 #include <asm/prom.h>
39 #include <asm/fs_pd.h>
40 
41 #include "cpm2_pic.h"
42 
43 /* External IRQS */
44 #define CPM2_IRQ_EXT1		19
45 #define CPM2_IRQ_EXT7		25
46 
47 /* Port C IRQS */
48 #define CPM2_IRQ_PORTC15	48
49 #define CPM2_IRQ_PORTC0		63
50 
51 static intctl_cpm2_t *cpm2_intctl;
52 
53 static struct device_node *cpm2_pic_node;
54 static struct irq_host *cpm2_pic_host;
55 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
56 static unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
57 
58 static const u_char irq_to_siureg[] = {
59 	1, 1, 1, 1, 1, 1, 1, 1,
60 	1, 1, 1, 1, 1, 1, 1, 1,
61 	0, 0, 0, 0, 0, 0, 0, 0,
62 	0, 0, 0, 0, 0, 0, 0, 0,
63 	1, 1, 1, 1, 1, 1, 1, 1,
64 	1, 1, 1, 1, 1, 1, 1, 1,
65 	0, 0, 0, 0, 0, 0, 0, 0,
66 	0, 0, 0, 0, 0, 0, 0, 0
67 };
68 
69 /* bit numbers do not match the docs, these are precomputed so the bit for
70  * a given irq is (1 << irq_to_siubit[irq]) */
71 static const u_char irq_to_siubit[] = {
72 	 0, 15, 14, 13, 12, 11, 10,  9,
73 	 8,  7,  6,  5,  4,  3,  2,  1,
74 	 2,  1,  0, 14, 13, 12, 11, 10,
75 	 9,  8,  7,  6,  5,  4,  3,  0,
76 	31, 30, 29, 28, 27, 26, 25, 24,
77 	23, 22, 21, 20, 19, 18, 17, 16,
78 	16, 17, 18, 19, 20, 21, 22, 23,
79 	24, 25, 26, 27, 28, 29, 30, 31,
80 };
81 
82 static void cpm2_mask_irq(unsigned int virq)
83 {
84 	int	bit, word;
85 	unsigned int irq_nr = virq_to_hw(virq);
86 
87 	bit = irq_to_siubit[irq_nr];
88 	word = irq_to_siureg[irq_nr];
89 
90 	ppc_cached_irq_mask[word] &= ~(1 << bit);
91 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
92 }
93 
94 static void cpm2_unmask_irq(unsigned int virq)
95 {
96 	int	bit, word;
97 	unsigned int irq_nr = virq_to_hw(virq);
98 
99 	bit = irq_to_siubit[irq_nr];
100 	word = irq_to_siureg[irq_nr];
101 
102 	ppc_cached_irq_mask[word] |= 1 << bit;
103 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
104 }
105 
106 static void cpm2_ack(unsigned int virq)
107 {
108 	int	bit, word;
109 	unsigned int irq_nr = virq_to_hw(virq);
110 
111 	bit = irq_to_siubit[irq_nr];
112 	word = irq_to_siureg[irq_nr];
113 
114 	out_be32(&cpm2_intctl->ic_sipnrh + word, 1 << bit);
115 }
116 
117 static void cpm2_end_irq(unsigned int virq)
118 {
119 	int	bit, word;
120 	unsigned int irq_nr = virq_to_hw(virq);
121 
122 	if (!(irq_desc[irq_nr].status & (IRQ_DISABLED|IRQ_INPROGRESS))
123 			&& irq_desc[irq_nr].action) {
124 
125 		bit = irq_to_siubit[irq_nr];
126 		word = irq_to_siureg[irq_nr];
127 
128 		ppc_cached_irq_mask[word] |= 1 << bit;
129 		out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
130 
131 		/*
132 		 * Work around large numbers of spurious IRQs on PowerPC 82xx
133 		 * systems.
134 		 */
135 		mb();
136 	}
137 }
138 
139 static int cpm2_set_irq_type(unsigned int virq, unsigned int flow_type)
140 {
141 	unsigned int src = virq_to_hw(virq);
142 	struct irq_desc *desc = get_irq_desc(virq);
143 	unsigned int vold, vnew, edibit;
144 
145 	if (flow_type == IRQ_TYPE_NONE)
146 		flow_type = IRQ_TYPE_LEVEL_LOW;
147 
148 	if (flow_type & IRQ_TYPE_EDGE_RISING) {
149 		printk(KERN_ERR "CPM2 PIC: sense type 0x%x not supported\n",
150 			flow_type);
151 		return -EINVAL;
152 	}
153 
154 	desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
155 	desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
156 	if (flow_type & IRQ_TYPE_LEVEL_LOW)  {
157 		desc->status |= IRQ_LEVEL;
158 		desc->handle_irq = handle_level_irq;
159 	} else
160 		desc->handle_irq = handle_edge_irq;
161 
162 	/* internal IRQ senses are LEVEL_LOW
163 	 * EXT IRQ and Port C IRQ senses are programmable
164 	 */
165 	if (src >= CPM2_IRQ_EXT1 && src <= CPM2_IRQ_EXT7)
166 			edibit = (14 - (src - CPM2_IRQ_EXT1));
167 	else
168 		if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0)
169 			edibit = (31 - (src - CPM2_IRQ_PORTC15));
170 		else
171 			return (flow_type & IRQ_TYPE_LEVEL_LOW) ? 0 : -EINVAL;
172 
173 	vold = in_be32(&cpm2_intctl->ic_siexr);
174 
175 	if ((flow_type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_FALLING)
176 		vnew = vold | (1 << edibit);
177 	else
178 		vnew = vold & ~(1 << edibit);
179 
180 	if (vold != vnew)
181 		out_be32(&cpm2_intctl->ic_siexr, vnew);
182 	return 0;
183 }
184 
185 static struct irq_chip cpm2_pic = {
186 	.typename = " CPM2 SIU ",
187 	.mask = cpm2_mask_irq,
188 	.unmask = cpm2_unmask_irq,
189 	.ack = cpm2_ack,
190 	.eoi = cpm2_end_irq,
191 	.set_type = cpm2_set_irq_type,
192 };
193 
194 unsigned int cpm2_get_irq(void)
195 {
196 	int irq;
197 	unsigned long bits;
198 
199        /* For CPM2, read the SIVEC register and shift the bits down
200          * to get the irq number.         */
201         bits = in_be32(&cpm2_intctl->ic_sivec);
202         irq = bits >> 26;
203 
204 	if (irq == 0)
205 		return(-1);
206 	return irq_linear_revmap(cpm2_pic_host, irq);
207 }
208 
209 static int cpm2_pic_host_match(struct irq_host *h, struct device_node *node)
210 {
211 	return cpm2_pic_node == node;
212 }
213 
214 static int cpm2_pic_host_map(struct irq_host *h, unsigned int virq,
215 			  irq_hw_number_t hw)
216 {
217 	pr_debug("cpm2_pic_host_map(%d, 0x%lx)\n", virq, hw);
218 
219 	get_irq_desc(virq)->status |= IRQ_LEVEL;
220 	set_irq_chip_and_handler(virq, &cpm2_pic, handle_level_irq);
221 	return 0;
222 }
223 
224 static int cpm2_pic_host_xlate(struct irq_host *h, struct device_node *ct,
225 			    u32 *intspec, unsigned int intsize,
226 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
227 {
228 	*out_hwirq = intspec[0];
229 	if (intsize > 1)
230 		*out_flags = intspec[1];
231 	else
232 		*out_flags = IRQ_TYPE_NONE;
233 	return 0;
234 }
235 
236 static struct irq_host_ops cpm2_pic_host_ops = {
237 	.match = cpm2_pic_host_match,
238 	.map = cpm2_pic_host_map,
239 	.xlate = cpm2_pic_host_xlate,
240 };
241 
242 void cpm2_pic_init(struct device_node *node)
243 {
244 	int i;
245 
246 	cpm2_intctl = cpm2_map(im_intctl);
247 
248 	/* Clear the CPM IRQ controller, in case it has any bits set
249 	 * from the bootloader
250 	 */
251 
252 	/* Mask out everything */
253 
254 	out_be32(&cpm2_intctl->ic_simrh, 0x00000000);
255 	out_be32(&cpm2_intctl->ic_simrl, 0x00000000);
256 
257 	wmb();
258 
259 	/* Ack everything */
260 	out_be32(&cpm2_intctl->ic_sipnrh, 0xffffffff);
261 	out_be32(&cpm2_intctl->ic_sipnrl, 0xffffffff);
262 	wmb();
263 
264 	/* Dummy read of the vector */
265 	i = in_be32(&cpm2_intctl->ic_sivec);
266 	rmb();
267 
268 	/* Initialize the default interrupt mapping priorities,
269 	 * in case the boot rom changed something on us.
270 	 */
271 	out_be16(&cpm2_intctl->ic_sicr, 0);
272 	out_be32(&cpm2_intctl->ic_scprrh, 0x05309770);
273 	out_be32(&cpm2_intctl->ic_scprrl, 0x05309770);
274 
275 	/* create a legacy host */
276 	cpm2_pic_node = of_node_get(node);
277 	cpm2_pic_host = irq_alloc_host(IRQ_HOST_MAP_LINEAR, 64, &cpm2_pic_host_ops, 64);
278 	if (cpm2_pic_host == NULL) {
279 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
280 		return;
281 	}
282 }
283