xref: /openbmc/linux/arch/powerpc/sysdev/cpm2_pic.c (revision e2eb96ae)
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/sched.h>
31 #include <linux/signal.h>
32 #include <linux/irq.h>
33 #include <linux/irqdomain.h>
34 
35 #include <asm/immap_cpm2.h>
36 #include <asm/io.h>
37 
38 #include "cpm2_pic.h"
39 
40 /* External IRQS */
41 #define CPM2_IRQ_EXT1		19
42 #define CPM2_IRQ_EXT7		25
43 
44 /* Port C IRQS */
45 #define CPM2_IRQ_PORTC15	48
46 #define CPM2_IRQ_PORTC0		63
47 
48 static intctl_cpm2_t __iomem *cpm2_intctl;
49 
50 static struct irq_domain *cpm2_pic_host;
51 static unsigned long ppc_cached_irq_mask[2]; /* 2 32-bit registers */
52 
53 static const u_char irq_to_siureg[] = {
54 	1, 1, 1, 1, 1, 1, 1, 1,
55 	1, 1, 1, 1, 1, 1, 1, 1,
56 	0, 0, 0, 0, 0, 0, 0, 0,
57 	0, 0, 0, 0, 0, 0, 0, 0,
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 };
63 
64 /* bit numbers do not match the docs, these are precomputed so the bit for
65  * a given irq is (1 << irq_to_siubit[irq]) */
66 static const u_char irq_to_siubit[] = {
67 	 0, 15, 14, 13, 12, 11, 10,  9,
68 	 8,  7,  6,  5,  4,  3,  2,  1,
69 	 2,  1,  0, 14, 13, 12, 11, 10,
70 	 9,  8,  7,  6,  5,  4,  3,  0,
71 	31, 30, 29, 28, 27, 26, 25, 24,
72 	23, 22, 21, 20, 19, 18, 17, 16,
73 	16, 17, 18, 19, 20, 21, 22, 23,
74 	24, 25, 26, 27, 28, 29, 30, 31,
75 };
76 
77 static void cpm2_mask_irq(struct irq_data *d)
78 {
79 	int	bit, word;
80 	unsigned int irq_nr = irqd_to_hwirq(d);
81 
82 	bit = irq_to_siubit[irq_nr];
83 	word = irq_to_siureg[irq_nr];
84 
85 	ppc_cached_irq_mask[word] &= ~(1 << bit);
86 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
87 }
88 
89 static void cpm2_unmask_irq(struct irq_data *d)
90 {
91 	int	bit, word;
92 	unsigned int irq_nr = irqd_to_hwirq(d);
93 
94 	bit = irq_to_siubit[irq_nr];
95 	word = irq_to_siureg[irq_nr];
96 
97 	ppc_cached_irq_mask[word] |= 1 << bit;
98 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
99 }
100 
101 static void cpm2_ack(struct irq_data *d)
102 {
103 	int	bit, word;
104 	unsigned int irq_nr = irqd_to_hwirq(d);
105 
106 	bit = irq_to_siubit[irq_nr];
107 	word = irq_to_siureg[irq_nr];
108 
109 	out_be32(&cpm2_intctl->ic_sipnrh + word, 1 << bit);
110 }
111 
112 static void cpm2_end_irq(struct irq_data *d)
113 {
114 	int	bit, word;
115 	unsigned int irq_nr = irqd_to_hwirq(d);
116 
117 	bit = irq_to_siubit[irq_nr];
118 	word = irq_to_siureg[irq_nr];
119 
120 	ppc_cached_irq_mask[word] |= 1 << bit;
121 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
122 
123 	/*
124 	 * Work around large numbers of spurious IRQs on PowerPC 82xx
125 	 * systems.
126 	 */
127 	mb();
128 }
129 
130 static int cpm2_set_irq_type(struct irq_data *d, unsigned int flow_type)
131 {
132 	unsigned int src = irqd_to_hwirq(d);
133 	unsigned int vold, vnew, edibit;
134 
135 	/* Port C interrupts are either IRQ_TYPE_EDGE_FALLING or
136 	 * IRQ_TYPE_EDGE_BOTH (default).  All others are IRQ_TYPE_EDGE_FALLING
137 	 * or IRQ_TYPE_LEVEL_LOW (default)
138 	 */
139 	if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0) {
140 		if (flow_type == IRQ_TYPE_NONE)
141 			flow_type = IRQ_TYPE_EDGE_BOTH;
142 
143 		if (flow_type != IRQ_TYPE_EDGE_BOTH &&
144 		    flow_type != IRQ_TYPE_EDGE_FALLING)
145 			goto err_sense;
146 	} else {
147 		if (flow_type == IRQ_TYPE_NONE)
148 			flow_type = IRQ_TYPE_LEVEL_LOW;
149 
150 		if (flow_type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH))
151 			goto err_sense;
152 	}
153 
154 	irqd_set_trigger_type(d, flow_type);
155 	if (flow_type & IRQ_TYPE_LEVEL_LOW)
156 		irq_set_handler_locked(d, handle_level_irq);
157 	else
158 		irq_set_handler_locked(d, handle_edge_irq);
159 
160 	/* internal IRQ senses are LEVEL_LOW
161 	 * EXT IRQ and Port C IRQ senses are programmable
162 	 */
163 	if (src >= CPM2_IRQ_EXT1 && src <= CPM2_IRQ_EXT7)
164 			edibit = (14 - (src - CPM2_IRQ_EXT1));
165 	else
166 		if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0)
167 			edibit = (31 - (CPM2_IRQ_PORTC0 - src));
168 		else
169 			return (flow_type & IRQ_TYPE_LEVEL_LOW) ?
170 				IRQ_SET_MASK_OK_NOCOPY : -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 IRQ_SET_MASK_OK_NOCOPY;
182 
183 err_sense:
184 	pr_err("CPM2 PIC: sense type 0x%x not supported\n", flow_type);
185 	return -EINVAL;
186 }
187 
188 static struct irq_chip cpm2_pic = {
189 	.name = "CPM2 SIU",
190 	.irq_mask = cpm2_mask_irq,
191 	.irq_unmask = cpm2_unmask_irq,
192 	.irq_ack = cpm2_ack,
193 	.irq_eoi = cpm2_end_irq,
194 	.irq_set_type = cpm2_set_irq_type,
195 	.flags = IRQCHIP_EOI_IF_HANDLED,
196 };
197 
198 unsigned int cpm2_get_irq(void)
199 {
200 	int irq;
201 	unsigned long bits;
202 
203        /* For CPM2, read the SIVEC register and shift the bits down
204          * to get the irq number.         */
205         bits = in_be32(&cpm2_intctl->ic_sivec);
206         irq = bits >> 26;
207 
208 	if (irq == 0)
209 		return(-1);
210 	return irq_linear_revmap(cpm2_pic_host, irq);
211 }
212 
213 static int cpm2_pic_host_map(struct irq_domain *h, unsigned int virq,
214 			  irq_hw_number_t hw)
215 {
216 	pr_debug("cpm2_pic_host_map(%d, 0x%lx)\n", virq, hw);
217 
218 	irq_set_status_flags(virq, IRQ_LEVEL);
219 	irq_set_chip_and_handler(virq, &cpm2_pic, handle_level_irq);
220 	return 0;
221 }
222 
223 static const struct irq_domain_ops cpm2_pic_host_ops = {
224 	.map = cpm2_pic_host_map,
225 	.xlate = irq_domain_xlate_onetwocell,
226 };
227 
228 void cpm2_pic_init(struct device_node *node)
229 {
230 	int i;
231 
232 	cpm2_intctl = &cpm2_immr->im_intctl;
233 
234 	/* Clear the CPM IRQ controller, in case it has any bits set
235 	 * from the bootloader
236 	 */
237 
238 	/* Mask out everything */
239 
240 	out_be32(&cpm2_intctl->ic_simrh, 0x00000000);
241 	out_be32(&cpm2_intctl->ic_simrl, 0x00000000);
242 
243 	wmb();
244 
245 	/* Ack everything */
246 	out_be32(&cpm2_intctl->ic_sipnrh, 0xffffffff);
247 	out_be32(&cpm2_intctl->ic_sipnrl, 0xffffffff);
248 	wmb();
249 
250 	/* Dummy read of the vector */
251 	i = in_be32(&cpm2_intctl->ic_sivec);
252 	rmb();
253 
254 	/* Initialize the default interrupt mapping priorities,
255 	 * in case the boot rom changed something on us.
256 	 */
257 	out_be16(&cpm2_intctl->ic_sicr, 0);
258 	out_be32(&cpm2_intctl->ic_scprrh, 0x05309770);
259 	out_be32(&cpm2_intctl->ic_scprrl, 0x05309770);
260 
261 	/* create a legacy host */
262 	cpm2_pic_host = irq_domain_add_linear(node, 64, &cpm2_pic_host_ops, NULL);
263 	if (cpm2_pic_host == NULL) {
264 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
265 		return;
266 	}
267 }
268