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/mpc8260.h>
37 #include <asm/io.h>
38 #include <asm/fs_pd.h>
39 
40 #include "cpm2_pic.h"
41 
42 /* External IRQS */
43 #define CPM2_IRQ_EXT1		19
44 #define CPM2_IRQ_EXT7		25
45 
46 /* Port C IRQS */
47 #define CPM2_IRQ_PORTC15	48
48 #define CPM2_IRQ_PORTC0		63
49 
50 static intctl_cpm2_t __iomem *cpm2_intctl;
51 
52 static struct irq_domain *cpm2_pic_host;
53 static unsigned long ppc_cached_irq_mask[2]; /* 2 32-bit registers */
54 
55 static const u_char irq_to_siureg[] = {
56 	1, 1, 1, 1, 1, 1, 1, 1,
57 	1, 1, 1, 1, 1, 1, 1, 1,
58 	0, 0, 0, 0, 0, 0, 0, 0,
59 	0, 0, 0, 0, 0, 0, 0, 0,
60 	1, 1, 1, 1, 1, 1, 1, 1,
61 	1, 1, 1, 1, 1, 1, 1, 1,
62 	0, 0, 0, 0, 0, 0, 0, 0,
63 	0, 0, 0, 0, 0, 0, 0, 0
64 };
65 
66 /* bit numbers do not match the docs, these are precomputed so the bit for
67  * a given irq is (1 << irq_to_siubit[irq]) */
68 static const u_char irq_to_siubit[] = {
69 	 0, 15, 14, 13, 12, 11, 10,  9,
70 	 8,  7,  6,  5,  4,  3,  2,  1,
71 	 2,  1,  0, 14, 13, 12, 11, 10,
72 	 9,  8,  7,  6,  5,  4,  3,  0,
73 	31, 30, 29, 28, 27, 26, 25, 24,
74 	23, 22, 21, 20, 19, 18, 17, 16,
75 	16, 17, 18, 19, 20, 21, 22, 23,
76 	24, 25, 26, 27, 28, 29, 30, 31,
77 };
78 
cpm2_mask_irq(struct irq_data * d)79 static void cpm2_mask_irq(struct irq_data *d)
80 {
81 	int	bit, word;
82 	unsigned int irq_nr = irqd_to_hwirq(d);
83 
84 	bit = irq_to_siubit[irq_nr];
85 	word = irq_to_siureg[irq_nr];
86 
87 	ppc_cached_irq_mask[word] &= ~(1 << bit);
88 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
89 }
90 
cpm2_unmask_irq(struct irq_data * d)91 static void cpm2_unmask_irq(struct irq_data *d)
92 {
93 	int	bit, word;
94 	unsigned int irq_nr = irqd_to_hwirq(d);
95 
96 	bit = irq_to_siubit[irq_nr];
97 	word = irq_to_siureg[irq_nr];
98 
99 	ppc_cached_irq_mask[word] |= 1 << bit;
100 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
101 }
102 
cpm2_ack(struct irq_data * d)103 static void cpm2_ack(struct irq_data *d)
104 {
105 	int	bit, word;
106 	unsigned int irq_nr = irqd_to_hwirq(d);
107 
108 	bit = irq_to_siubit[irq_nr];
109 	word = irq_to_siureg[irq_nr];
110 
111 	out_be32(&cpm2_intctl->ic_sipnrh + word, 1 << bit);
112 }
113 
cpm2_end_irq(struct irq_data * d)114 static void cpm2_end_irq(struct irq_data *d)
115 {
116 	int	bit, word;
117 	unsigned int irq_nr = irqd_to_hwirq(d);
118 
119 	bit = irq_to_siubit[irq_nr];
120 	word = irq_to_siureg[irq_nr];
121 
122 	ppc_cached_irq_mask[word] |= 1 << bit;
123 	out_be32(&cpm2_intctl->ic_simrh + word, ppc_cached_irq_mask[word]);
124 
125 	/*
126 	 * Work around large numbers of spurious IRQs on PowerPC 82xx
127 	 * systems.
128 	 */
129 	mb();
130 }
131 
cpm2_set_irq_type(struct irq_data * d,unsigned int flow_type)132 static int cpm2_set_irq_type(struct irq_data *d, unsigned int flow_type)
133 {
134 	unsigned int src = irqd_to_hwirq(d);
135 	unsigned int vold, vnew, edibit;
136 
137 	/* Port C interrupts are either IRQ_TYPE_EDGE_FALLING or
138 	 * IRQ_TYPE_EDGE_BOTH (default).  All others are IRQ_TYPE_EDGE_FALLING
139 	 * or IRQ_TYPE_LEVEL_LOW (default)
140 	 */
141 	if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0) {
142 		if (flow_type == IRQ_TYPE_NONE)
143 			flow_type = IRQ_TYPE_EDGE_BOTH;
144 
145 		if (flow_type != IRQ_TYPE_EDGE_BOTH &&
146 		    flow_type != IRQ_TYPE_EDGE_FALLING)
147 			goto err_sense;
148 	} else {
149 		if (flow_type == IRQ_TYPE_NONE)
150 			flow_type = IRQ_TYPE_LEVEL_LOW;
151 
152 		if (flow_type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH))
153 			goto err_sense;
154 	}
155 
156 	irqd_set_trigger_type(d, flow_type);
157 	if (flow_type & IRQ_TYPE_LEVEL_LOW)
158 		irq_set_handler_locked(d, handle_level_irq);
159 	else
160 		irq_set_handler_locked(d, 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 - (CPM2_IRQ_PORTC0 - src));
170 		else
171 			return (flow_type & IRQ_TYPE_LEVEL_LOW) ?
172 				IRQ_SET_MASK_OK_NOCOPY : -EINVAL;
173 
174 	vold = in_be32(&cpm2_intctl->ic_siexr);
175 
176 	if ((flow_type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_FALLING)
177 		vnew = vold | (1 << edibit);
178 	else
179 		vnew = vold & ~(1 << edibit);
180 
181 	if (vold != vnew)
182 		out_be32(&cpm2_intctl->ic_siexr, vnew);
183 	return IRQ_SET_MASK_OK_NOCOPY;
184 
185 err_sense:
186 	pr_err("CPM2 PIC: sense type 0x%x not supported\n", flow_type);
187 	return -EINVAL;
188 }
189 
190 static struct irq_chip cpm2_pic = {
191 	.name = "CPM2 SIU",
192 	.irq_mask = cpm2_mask_irq,
193 	.irq_unmask = cpm2_unmask_irq,
194 	.irq_ack = cpm2_ack,
195 	.irq_eoi = cpm2_end_irq,
196 	.irq_set_type = cpm2_set_irq_type,
197 	.flags = IRQCHIP_EOI_IF_HANDLED,
198 };
199 
cpm2_get_irq(void)200 unsigned int cpm2_get_irq(void)
201 {
202 	int irq;
203 	unsigned long bits;
204 
205        /* For CPM2, read the SIVEC register and shift the bits down
206          * to get the irq number.         */
207         bits = in_be32(&cpm2_intctl->ic_sivec);
208         irq = bits >> 26;
209 
210 	if (irq == 0)
211 		return(-1);
212 	return irq_linear_revmap(cpm2_pic_host, irq);
213 }
214 
cpm2_pic_host_map(struct irq_domain * h,unsigned int virq,irq_hw_number_t hw)215 static int cpm2_pic_host_map(struct irq_domain *h, unsigned int virq,
216 			  irq_hw_number_t hw)
217 {
218 	pr_debug("cpm2_pic_host_map(%d, 0x%lx)\n", virq, hw);
219 
220 	irq_set_status_flags(virq, IRQ_LEVEL);
221 	irq_set_chip_and_handler(virq, &cpm2_pic, handle_level_irq);
222 	return 0;
223 }
224 
225 static const struct irq_domain_ops cpm2_pic_host_ops = {
226 	.map = cpm2_pic_host_map,
227 	.xlate = irq_domain_xlate_onetwocell,
228 };
229 
cpm2_pic_init(struct device_node * node)230 void cpm2_pic_init(struct device_node *node)
231 {
232 	int i;
233 
234 	cpm2_intctl = cpm2_map(im_intctl);
235 
236 	/* Clear the CPM IRQ controller, in case it has any bits set
237 	 * from the bootloader
238 	 */
239 
240 	/* Mask out everything */
241 
242 	out_be32(&cpm2_intctl->ic_simrh, 0x00000000);
243 	out_be32(&cpm2_intctl->ic_simrl, 0x00000000);
244 
245 	wmb();
246 
247 	/* Ack everything */
248 	out_be32(&cpm2_intctl->ic_sipnrh, 0xffffffff);
249 	out_be32(&cpm2_intctl->ic_sipnrl, 0xffffffff);
250 	wmb();
251 
252 	/* Dummy read of the vector */
253 	i = in_be32(&cpm2_intctl->ic_sivec);
254 	rmb();
255 
256 	/* Initialize the default interrupt mapping priorities,
257 	 * in case the boot rom changed something on us.
258 	 */
259 	out_be16(&cpm2_intctl->ic_sicr, 0);
260 	out_be32(&cpm2_intctl->ic_scprrh, 0x05309770);
261 	out_be32(&cpm2_intctl->ic_scprrl, 0x05309770);
262 
263 	/* create a legacy host */
264 	cpm2_pic_host = irq_domain_add_linear(node, 64, &cpm2_pic_host_ops, NULL);
265 	if (cpm2_pic_host == NULL) {
266 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
267 		return;
268 	}
269 }
270