xref: /openbmc/linux/arch/powerpc/sysdev/cpm2_pic.c (revision 95e9fd10)
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_domain *cpm2_pic_host;
54 static unsigned long ppc_cached_irq_mask[2]; /* 2 32-bit registers */
55 
56 static const u_char irq_to_siureg[] = {
57 	1, 1, 1, 1, 1, 1, 1, 1,
58 	1, 1, 1, 1, 1, 1, 1, 1,
59 	0, 0, 0, 0, 0, 0, 0, 0,
60 	0, 0, 0, 0, 0, 0, 0, 0,
61 	1, 1, 1, 1, 1, 1, 1, 1,
62 	1, 1, 1, 1, 1, 1, 1, 1,
63 	0, 0, 0, 0, 0, 0, 0, 0,
64 	0, 0, 0, 0, 0, 0, 0, 0
65 };
66 
67 /* bit numbers do not match the docs, these are precomputed so the bit for
68  * a given irq is (1 << irq_to_siubit[irq]) */
69 static const u_char irq_to_siubit[] = {
70 	 0, 15, 14, 13, 12, 11, 10,  9,
71 	 8,  7,  6,  5,  4,  3,  2,  1,
72 	 2,  1,  0, 14, 13, 12, 11, 10,
73 	 9,  8,  7,  6,  5,  4,  3,  0,
74 	31, 30, 29, 28, 27, 26, 25, 24,
75 	23, 22, 21, 20, 19, 18, 17, 16,
76 	16, 17, 18, 19, 20, 21, 22, 23,
77 	24, 25, 26, 27, 28, 29, 30, 31,
78 };
79 
80 static void cpm2_mask_irq(struct irq_data *d)
81 {
82 	int	bit, word;
83 	unsigned int irq_nr = irqd_to_hwirq(d);
84 
85 	bit = irq_to_siubit[irq_nr];
86 	word = irq_to_siureg[irq_nr];
87 
88 	ppc_cached_irq_mask[word] &= ~(1 << bit);
89 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
90 }
91 
92 static void cpm2_unmask_irq(struct irq_data *d)
93 {
94 	int	bit, word;
95 	unsigned int irq_nr = irqd_to_hwirq(d);
96 
97 	bit = irq_to_siubit[irq_nr];
98 	word = irq_to_siureg[irq_nr];
99 
100 	ppc_cached_irq_mask[word] |= 1 << bit;
101 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
102 }
103 
104 static void cpm2_ack(struct irq_data *d)
105 {
106 	int	bit, word;
107 	unsigned int irq_nr = irqd_to_hwirq(d);
108 
109 	bit = irq_to_siubit[irq_nr];
110 	word = irq_to_siureg[irq_nr];
111 
112 	out_be32(&cpm2_intctl->ic_sipnrh + word, 1 << bit);
113 }
114 
115 static void cpm2_end_irq(struct irq_data *d)
116 {
117 	int	bit, word;
118 	unsigned int irq_nr = irqd_to_hwirq(d);
119 
120 	bit = irq_to_siubit[irq_nr];
121 	word = irq_to_siureg[irq_nr];
122 
123 	ppc_cached_irq_mask[word] |= 1 << bit;
124 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
125 
126 	/*
127 	 * Work around large numbers of spurious IRQs on PowerPC 82xx
128 	 * systems.
129 	 */
130 	mb();
131 }
132 
133 static int cpm2_set_irq_type(struct irq_data *d, unsigned int flow_type)
134 {
135 	unsigned int src = irqd_to_hwirq(d);
136 	unsigned int vold, vnew, edibit;
137 
138 	/* Port C interrupts are either IRQ_TYPE_EDGE_FALLING or
139 	 * IRQ_TYPE_EDGE_BOTH (default).  All others are IRQ_TYPE_EDGE_FALLING
140 	 * or IRQ_TYPE_LEVEL_LOW (default)
141 	 */
142 	if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0) {
143 		if (flow_type == IRQ_TYPE_NONE)
144 			flow_type = IRQ_TYPE_EDGE_BOTH;
145 
146 		if (flow_type != IRQ_TYPE_EDGE_BOTH &&
147 		    flow_type != IRQ_TYPE_EDGE_FALLING)
148 			goto err_sense;
149 	} else {
150 		if (flow_type == IRQ_TYPE_NONE)
151 			flow_type = IRQ_TYPE_LEVEL_LOW;
152 
153 		if (flow_type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH))
154 			goto err_sense;
155 	}
156 
157 	irqd_set_trigger_type(d, flow_type);
158 	if (flow_type & IRQ_TYPE_LEVEL_LOW)
159 		__irq_set_handler_locked(d->irq, handle_level_irq);
160 	else
161 		__irq_set_handler_locked(d->irq, handle_edge_irq);
162 
163 	/* internal IRQ senses are LEVEL_LOW
164 	 * EXT IRQ and Port C IRQ senses are programmable
165 	 */
166 	if (src >= CPM2_IRQ_EXT1 && src <= CPM2_IRQ_EXT7)
167 			edibit = (14 - (src - CPM2_IRQ_EXT1));
168 	else
169 		if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0)
170 			edibit = (31 - (CPM2_IRQ_PORTC0 - src));
171 		else
172 			return (flow_type & IRQ_TYPE_LEVEL_LOW) ?
173 				IRQ_SET_MASK_OK_NOCOPY : -EINVAL;
174 
175 	vold = in_be32(&cpm2_intctl->ic_siexr);
176 
177 	if ((flow_type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_FALLING)
178 		vnew = vold | (1 << edibit);
179 	else
180 		vnew = vold & ~(1 << edibit);
181 
182 	if (vold != vnew)
183 		out_be32(&cpm2_intctl->ic_siexr, vnew);
184 	return IRQ_SET_MASK_OK_NOCOPY;
185 
186 err_sense:
187 	pr_err("CPM2 PIC: sense type 0x%x not supported\n", flow_type);
188 	return -EINVAL;
189 }
190 
191 static struct irq_chip cpm2_pic = {
192 	.name = "CPM2 SIU",
193 	.irq_mask = cpm2_mask_irq,
194 	.irq_unmask = cpm2_unmask_irq,
195 	.irq_ack = cpm2_ack,
196 	.irq_eoi = cpm2_end_irq,
197 	.irq_set_type = cpm2_set_irq_type,
198 	.flags = IRQCHIP_EOI_IF_HANDLED,
199 };
200 
201 unsigned int cpm2_get_irq(void)
202 {
203 	int irq;
204 	unsigned long bits;
205 
206        /* For CPM2, read the SIVEC register and shift the bits down
207          * to get the irq number.         */
208         bits = in_be32(&cpm2_intctl->ic_sivec);
209         irq = bits >> 26;
210 
211 	if (irq == 0)
212 		return(-1);
213 	return irq_linear_revmap(cpm2_pic_host, irq);
214 }
215 
216 static int cpm2_pic_host_map(struct irq_domain *h, unsigned int virq,
217 			  irq_hw_number_t hw)
218 {
219 	pr_debug("cpm2_pic_host_map(%d, 0x%lx)\n", virq, hw);
220 
221 	irq_set_status_flags(virq, IRQ_LEVEL);
222 	irq_set_chip_and_handler(virq, &cpm2_pic, handle_level_irq);
223 	return 0;
224 }
225 
226 static const struct irq_domain_ops cpm2_pic_host_ops = {
227 	.map = cpm2_pic_host_map,
228 	.xlate = irq_domain_xlate_onetwocell,
229 };
230 
231 void cpm2_pic_init(struct device_node *node)
232 {
233 	int i;
234 
235 	cpm2_intctl = cpm2_map(im_intctl);
236 
237 	/* Clear the CPM IRQ controller, in case it has any bits set
238 	 * from the bootloader
239 	 */
240 
241 	/* Mask out everything */
242 
243 	out_be32(&cpm2_intctl->ic_simrh, 0x00000000);
244 	out_be32(&cpm2_intctl->ic_simrl, 0x00000000);
245 
246 	wmb();
247 
248 	/* Ack everything */
249 	out_be32(&cpm2_intctl->ic_sipnrh, 0xffffffff);
250 	out_be32(&cpm2_intctl->ic_sipnrl, 0xffffffff);
251 	wmb();
252 
253 	/* Dummy read of the vector */
254 	i = in_be32(&cpm2_intctl->ic_sivec);
255 	rmb();
256 
257 	/* Initialize the default interrupt mapping priorities,
258 	 * in case the boot rom changed something on us.
259 	 */
260 	out_be16(&cpm2_intctl->ic_sicr, 0);
261 	out_be32(&cpm2_intctl->ic_scprrh, 0x05309770);
262 	out_be32(&cpm2_intctl->ic_scprrl, 0x05309770);
263 
264 	/* create a legacy host */
265 	cpm2_pic_host = irq_domain_add_linear(node, 64, &cpm2_pic_host_ops, NULL);
266 	if (cpm2_pic_host == NULL) {
267 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
268 		return;
269 	}
270 }
271