xref: /linux/arch/powerpc/sysdev/cpm2_pic.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
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(struct irq_data *d)
82 {
83 	int	bit, word;
84 	unsigned int irq_nr = irqd_to_hwirq(d);
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(struct irq_data *d)
94 {
95 	int	bit, word;
96 	unsigned int irq_nr = irqd_to_hwirq(d);
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(struct irq_data *d)
106 {
107 	int	bit, word;
108 	unsigned int irq_nr = irqd_to_hwirq(d);
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(struct irq_data *d)
117 {
118 	int	bit, word;
119 	unsigned int irq_nr = irqd_to_hwirq(d);
120 
121 	bit = irq_to_siubit[irq_nr];
122 	word = irq_to_siureg[irq_nr];
123 
124 	ppc_cached_irq_mask[word] |= 1 << bit;
125 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
126 
127 	/*
128 	 * Work around large numbers of spurious IRQs on PowerPC 82xx
129 	 * systems.
130 	 */
131 	mb();
132 }
133 
134 static int cpm2_set_irq_type(struct irq_data *d, unsigned int flow_type)
135 {
136 	unsigned int src = irqd_to_hwirq(d);
137 	unsigned int vold, vnew, edibit;
138 
139 	/* Port C interrupts are either IRQ_TYPE_EDGE_FALLING or
140 	 * IRQ_TYPE_EDGE_BOTH (default).  All others are IRQ_TYPE_EDGE_FALLING
141 	 * or IRQ_TYPE_LEVEL_LOW (default)
142 	 */
143 	if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0) {
144 		if (flow_type == IRQ_TYPE_NONE)
145 			flow_type = IRQ_TYPE_EDGE_BOTH;
146 
147 		if (flow_type != IRQ_TYPE_EDGE_BOTH &&
148 		    flow_type != IRQ_TYPE_EDGE_FALLING)
149 			goto err_sense;
150 	} else {
151 		if (flow_type == IRQ_TYPE_NONE)
152 			flow_type = IRQ_TYPE_LEVEL_LOW;
153 
154 		if (flow_type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH))
155 			goto err_sense;
156 	}
157 
158 	irqd_set_trigger_type(d, flow_type);
159 	if (flow_type & IRQ_TYPE_LEVEL_LOW)
160 		__irq_set_handler_locked(d->irq, handle_level_irq);
161 	else
162 		__irq_set_handler_locked(d->irq, handle_edge_irq);
163 
164 	/* internal IRQ senses are LEVEL_LOW
165 	 * EXT IRQ and Port C IRQ senses are programmable
166 	 */
167 	if (src >= CPM2_IRQ_EXT1 && src <= CPM2_IRQ_EXT7)
168 			edibit = (14 - (src - CPM2_IRQ_EXT1));
169 	else
170 		if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0)
171 			edibit = (31 - (CPM2_IRQ_PORTC0 - src));
172 		else
173 			return (flow_type & IRQ_TYPE_LEVEL_LOW) ?
174 				IRQ_SET_MASK_OK_NOCOPY : -EINVAL;
175 
176 	vold = in_be32(&cpm2_intctl->ic_siexr);
177 
178 	if ((flow_type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_FALLING)
179 		vnew = vold | (1 << edibit);
180 	else
181 		vnew = vold & ~(1 << edibit);
182 
183 	if (vold != vnew)
184 		out_be32(&cpm2_intctl->ic_siexr, vnew);
185 	return IRQ_SET_MASK_OK_NOCOPY;
186 
187 err_sense:
188 	pr_err("CPM2 PIC: sense type 0x%x not supported\n", flow_type);
189 	return -EINVAL;
190 }
191 
192 static struct irq_chip cpm2_pic = {
193 	.name = "CPM2 SIU",
194 	.irq_mask = cpm2_mask_irq,
195 	.irq_unmask = cpm2_unmask_irq,
196 	.irq_ack = cpm2_ack,
197 	.irq_eoi = cpm2_end_irq,
198 	.irq_set_type = cpm2_set_irq_type,
199 	.flags = IRQCHIP_EOI_IF_HANDLED,
200 };
201 
202 unsigned int cpm2_get_irq(void)
203 {
204 	int irq;
205 	unsigned long bits;
206 
207        /* For CPM2, read the SIVEC register and shift the bits down
208          * to get the irq number.         */
209         bits = in_be32(&cpm2_intctl->ic_sivec);
210         irq = bits >> 26;
211 
212 	if (irq == 0)
213 		return(-1);
214 	return irq_linear_revmap(cpm2_pic_host, irq);
215 }
216 
217 static int cpm2_pic_host_map(struct irq_host *h, unsigned int virq,
218 			  irq_hw_number_t hw)
219 {
220 	pr_debug("cpm2_pic_host_map(%d, 0x%lx)\n", virq, hw);
221 
222 	irq_set_status_flags(virq, IRQ_LEVEL);
223 	irq_set_chip_and_handler(virq, &cpm2_pic, handle_level_irq);
224 	return 0;
225 }
226 
227 static int cpm2_pic_host_xlate(struct irq_host *h, struct device_node *ct,
228 			    const u32 *intspec, unsigned int intsize,
229 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
230 {
231 	*out_hwirq = intspec[0];
232 	if (intsize > 1)
233 		*out_flags = intspec[1];
234 	else
235 		*out_flags = IRQ_TYPE_NONE;
236 	return 0;
237 }
238 
239 static struct irq_host_ops cpm2_pic_host_ops = {
240 	.map = cpm2_pic_host_map,
241 	.xlate = cpm2_pic_host_xlate,
242 };
243 
244 void cpm2_pic_init(struct device_node *node)
245 {
246 	int i;
247 
248 	cpm2_intctl = cpm2_map(im_intctl);
249 
250 	/* Clear the CPM IRQ controller, in case it has any bits set
251 	 * from the bootloader
252 	 */
253 
254 	/* Mask out everything */
255 
256 	out_be32(&cpm2_intctl->ic_simrh, 0x00000000);
257 	out_be32(&cpm2_intctl->ic_simrl, 0x00000000);
258 
259 	wmb();
260 
261 	/* Ack everything */
262 	out_be32(&cpm2_intctl->ic_sipnrh, 0xffffffff);
263 	out_be32(&cpm2_intctl->ic_sipnrl, 0xffffffff);
264 	wmb();
265 
266 	/* Dummy read of the vector */
267 	i = in_be32(&cpm2_intctl->ic_sivec);
268 	rmb();
269 
270 	/* Initialize the default interrupt mapping priorities,
271 	 * in case the boot rom changed something on us.
272 	 */
273 	out_be16(&cpm2_intctl->ic_sicr, 0);
274 	out_be32(&cpm2_intctl->ic_scprrh, 0x05309770);
275 	out_be32(&cpm2_intctl->ic_scprrl, 0x05309770);
276 
277 	/* create a legacy host */
278 	cpm2_pic_host = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR,
279 				       64, &cpm2_pic_host_ops, 64);
280 	if (cpm2_pic_host == NULL) {
281 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
282 		return;
283 	}
284 }
285