xref: /openbmc/linux/arch/powerpc/sysdev/cpm2_pic.c (revision b04b4f78)
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 __iomem *cpm2_intctl;
52 
53 static struct irq_host *cpm2_pic_host;
54 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
55 static unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
56 
57 static const u_char irq_to_siureg[] = {
58 	1, 1, 1, 1, 1, 1, 1, 1,
59 	1, 1, 1, 1, 1, 1, 1, 1,
60 	0, 0, 0, 0, 0, 0, 0, 0,
61 	0, 0, 0, 0, 0, 0, 0, 0,
62 	1, 1, 1, 1, 1, 1, 1, 1,
63 	1, 1, 1, 1, 1, 1, 1, 1,
64 	0, 0, 0, 0, 0, 0, 0, 0,
65 	0, 0, 0, 0, 0, 0, 0, 0
66 };
67 
68 /* bit numbers do not match the docs, these are precomputed so the bit for
69  * a given irq is (1 << irq_to_siubit[irq]) */
70 static const u_char irq_to_siubit[] = {
71 	 0, 15, 14, 13, 12, 11, 10,  9,
72 	 8,  7,  6,  5,  4,  3,  2,  1,
73 	 2,  1,  0, 14, 13, 12, 11, 10,
74 	 9,  8,  7,  6,  5,  4,  3,  0,
75 	31, 30, 29, 28, 27, 26, 25, 24,
76 	23, 22, 21, 20, 19, 18, 17, 16,
77 	16, 17, 18, 19, 20, 21, 22, 23,
78 	24, 25, 26, 27, 28, 29, 30, 31,
79 };
80 
81 static void cpm2_mask_irq(unsigned int virq)
82 {
83 	int	bit, word;
84 	unsigned int irq_nr = virq_to_hw(virq);
85 
86 	bit = irq_to_siubit[irq_nr];
87 	word = irq_to_siureg[irq_nr];
88 
89 	ppc_cached_irq_mask[word] &= ~(1 << bit);
90 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
91 }
92 
93 static void cpm2_unmask_irq(unsigned int virq)
94 {
95 	int	bit, word;
96 	unsigned int irq_nr = virq_to_hw(virq);
97 
98 	bit = irq_to_siubit[irq_nr];
99 	word = irq_to_siureg[irq_nr];
100 
101 	ppc_cached_irq_mask[word] |= 1 << bit;
102 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
103 }
104 
105 static void cpm2_ack(unsigned int virq)
106 {
107 	int	bit, word;
108 	unsigned int irq_nr = virq_to_hw(virq);
109 
110 	bit = irq_to_siubit[irq_nr];
111 	word = irq_to_siureg[irq_nr];
112 
113 	out_be32(&cpm2_intctl->ic_sipnrh + word, 1 << bit);
114 }
115 
116 static void cpm2_end_irq(unsigned int virq)
117 {
118 	int	bit, word;
119 	unsigned int irq_nr = virq_to_hw(virq);
120 
121 	if (!(irq_desc[irq_nr].status & (IRQ_DISABLED|IRQ_INPROGRESS))
122 			&& irq_desc[irq_nr].action) {
123 
124 		bit = irq_to_siubit[irq_nr];
125 		word = irq_to_siureg[irq_nr];
126 
127 		ppc_cached_irq_mask[word] |= 1 << bit;
128 		out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
129 
130 		/*
131 		 * Work around large numbers of spurious IRQs on PowerPC 82xx
132 		 * systems.
133 		 */
134 		mb();
135 	}
136 }
137 
138 static int cpm2_set_irq_type(unsigned int virq, unsigned int flow_type)
139 {
140 	unsigned int src = virq_to_hw(virq);
141 	struct irq_desc *desc = get_irq_desc(virq);
142 	unsigned int vold, vnew, edibit;
143 
144 	if (flow_type == IRQ_TYPE_NONE)
145 		flow_type = IRQ_TYPE_LEVEL_LOW;
146 
147 	if (flow_type & IRQ_TYPE_EDGE_RISING) {
148 		printk(KERN_ERR "CPM2 PIC: sense type 0x%x not supported\n",
149 			flow_type);
150 		return -EINVAL;
151 	}
152 
153 	desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
154 	desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
155 	if (flow_type & IRQ_TYPE_LEVEL_LOW)  {
156 		desc->status |= IRQ_LEVEL;
157 		desc->handle_irq = handle_level_irq;
158 	} else
159 		desc->handle_irq = handle_edge_irq;
160 
161 	/* internal IRQ senses are LEVEL_LOW
162 	 * EXT IRQ and Port C IRQ senses are programmable
163 	 */
164 	if (src >= CPM2_IRQ_EXT1 && src <= CPM2_IRQ_EXT7)
165 			edibit = (14 - (src - CPM2_IRQ_EXT1));
166 	else
167 		if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0)
168 			edibit = (31 - (CPM2_IRQ_PORTC0 - src));
169 		else
170 			return (flow_type & IRQ_TYPE_LEVEL_LOW) ? 0 : -EINVAL;
171 
172 	vold = in_be32(&cpm2_intctl->ic_siexr);
173 
174 	if ((flow_type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_FALLING)
175 		vnew = vold | (1 << edibit);
176 	else
177 		vnew = vold & ~(1 << edibit);
178 
179 	if (vold != vnew)
180 		out_be32(&cpm2_intctl->ic_siexr, vnew);
181 	return 0;
182 }
183 
184 static struct irq_chip cpm2_pic = {
185 	.typename = " CPM2 SIU ",
186 	.mask = cpm2_mask_irq,
187 	.unmask = cpm2_unmask_irq,
188 	.ack = cpm2_ack,
189 	.eoi = cpm2_end_irq,
190 	.set_type = cpm2_set_irq_type,
191 };
192 
193 unsigned int cpm2_get_irq(void)
194 {
195 	int irq;
196 	unsigned long bits;
197 
198        /* For CPM2, read the SIVEC register and shift the bits down
199          * to get the irq number.         */
200         bits = in_be32(&cpm2_intctl->ic_sivec);
201         irq = bits >> 26;
202 
203 	if (irq == 0)
204 		return(-1);
205 	return irq_linear_revmap(cpm2_pic_host, irq);
206 }
207 
208 static int cpm2_pic_host_map(struct irq_host *h, unsigned int virq,
209 			  irq_hw_number_t hw)
210 {
211 	pr_debug("cpm2_pic_host_map(%d, 0x%lx)\n", virq, hw);
212 
213 	get_irq_desc(virq)->status |= IRQ_LEVEL;
214 	set_irq_chip_and_handler(virq, &cpm2_pic, handle_level_irq);
215 	return 0;
216 }
217 
218 static int cpm2_pic_host_xlate(struct irq_host *h, struct device_node *ct,
219 			    u32 *intspec, unsigned int intsize,
220 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
221 {
222 	*out_hwirq = intspec[0];
223 	if (intsize > 1)
224 		*out_flags = intspec[1];
225 	else
226 		*out_flags = IRQ_TYPE_NONE;
227 	return 0;
228 }
229 
230 static struct irq_host_ops cpm2_pic_host_ops = {
231 	.map = cpm2_pic_host_map,
232 	.xlate = cpm2_pic_host_xlate,
233 };
234 
235 void cpm2_pic_init(struct device_node *node)
236 {
237 	int i;
238 
239 	cpm2_intctl = cpm2_map(im_intctl);
240 
241 	/* Clear the CPM IRQ controller, in case it has any bits set
242 	 * from the bootloader
243 	 */
244 
245 	/* Mask out everything */
246 
247 	out_be32(&cpm2_intctl->ic_simrh, 0x00000000);
248 	out_be32(&cpm2_intctl->ic_simrl, 0x00000000);
249 
250 	wmb();
251 
252 	/* Ack everything */
253 	out_be32(&cpm2_intctl->ic_sipnrh, 0xffffffff);
254 	out_be32(&cpm2_intctl->ic_sipnrl, 0xffffffff);
255 	wmb();
256 
257 	/* Dummy read of the vector */
258 	i = in_be32(&cpm2_intctl->ic_sivec);
259 	rmb();
260 
261 	/* Initialize the default interrupt mapping priorities,
262 	 * in case the boot rom changed something on us.
263 	 */
264 	out_be16(&cpm2_intctl->ic_sicr, 0);
265 	out_be32(&cpm2_intctl->ic_scprrh, 0x05309770);
266 	out_be32(&cpm2_intctl->ic_scprrl, 0x05309770);
267 
268 	/* create a legacy host */
269 	cpm2_pic_host = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR,
270 				       64, &cpm2_pic_host_ops, 64);
271 	if (cpm2_pic_host == NULL) {
272 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
273 		return;
274 	}
275 }
276