xref: /openbmc/linux/arch/mips/kernel/irq_txx9.c (revision 8bdc2a19)
1 /*
2  * Based on linux/arch/mips/jmr3927/rbhma3100/irq.c,
3  *	    linux/arch/mips/tx4927/common/tx4927_irq.c,
4  *	    linux/arch/mips/tx4938/common/irq.c
5  *
6  * Copyright 2001, 2003-2005 MontaVista Software Inc.
7  * Author: MontaVista Software, Inc.
8  *	   ahennessy@mvista.com
9  *	   source@mvista.com
10  * Copyright (C) 2000-2001 Toshiba Corporation
11  *
12  * This file is subject to the terms and conditions of the GNU General Public
13  * License.  See the file "COPYING" in the main directory of this archive
14  * for more details.
15  */
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/types.h>
19 #include <linux/irq.h>
20 #include <asm/txx9irq.h>
21 
22 struct txx9_irc_reg {
23 	u32 cer;
24 	u32 cr[2];
25 	u32 unused0;
26 	u32 ilr[8];
27 	u32 unused1[4];
28 	u32 imr;
29 	u32 unused2[7];
30 	u32 scr;
31 	u32 unused3[7];
32 	u32 ssr;
33 	u32 unused4[7];
34 	u32 csr;
35 };
36 
37 /* IRCER : Int. Control Enable */
38 #define TXx9_IRCER_ICE	0x00000001
39 
40 /* IRCR : Int. Control */
41 #define TXx9_IRCR_LOW	0x00000000
42 #define TXx9_IRCR_HIGH	0x00000001
43 #define TXx9_IRCR_DOWN	0x00000002
44 #define TXx9_IRCR_UP	0x00000003
45 #define TXx9_IRCR_EDGE(cr)	((cr) & 0x00000002)
46 
47 /* IRSCR : Int. Status Control */
48 #define TXx9_IRSCR_EIClrE	0x00000100
49 #define TXx9_IRSCR_EIClr_MASK	0x0000000f
50 
51 /* IRCSR : Int. Current Status */
52 #define TXx9_IRCSR_IF	0x00010000
53 #define TXx9_IRCSR_ILV_MASK	0x00000700
54 #define TXx9_IRCSR_IVL_MASK	0x0000001f
55 
56 #define irc_dlevel	0
57 #define irc_elevel	1
58 
59 static struct txx9_irc_reg __iomem *txx9_ircptr __read_mostly;
60 
61 static struct {
62 	unsigned char level;
63 	unsigned char mode;
64 } txx9irq[TXx9_MAX_IR] __read_mostly;
65 
66 static void txx9_irq_unmask(struct irq_data *d)
67 {
68 	unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
69 	u32 __iomem *ilrp = &txx9_ircptr->ilr[(irq_nr % 16 ) / 2];
70 	int ofs = irq_nr / 16 * 16 + (irq_nr & 1) * 8;
71 
72 	__raw_writel((__raw_readl(ilrp) & ~(0xff << ofs))
73 		     | (txx9irq[irq_nr].level << ofs),
74 		     ilrp);
75 }
76 
77 static inline void txx9_irq_mask(struct irq_data *d)
78 {
79 	unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
80 	u32 __iomem *ilrp = &txx9_ircptr->ilr[(irq_nr % 16) / 2];
81 	int ofs = irq_nr / 16 * 16 + (irq_nr & 1) * 8;
82 
83 	__raw_writel((__raw_readl(ilrp) & ~(0xff << ofs))
84 		     | (irc_dlevel << ofs),
85 		     ilrp);
86 	mmiowb();
87 }
88 
89 static void txx9_irq_mask_ack(struct irq_data *d)
90 {
91 	unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
92 
93 	txx9_irq_mask(d);
94 	/* clear edge detection */
95 	if (unlikely(TXx9_IRCR_EDGE(txx9irq[irq_nr].mode)))
96 		__raw_writel(TXx9_IRSCR_EIClrE | irq_nr, &txx9_ircptr->scr);
97 }
98 
99 static int txx9_irq_set_type(struct irq_data *d, unsigned int flow_type)
100 {
101 	unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
102 	u32 cr;
103 	u32 __iomem *crp;
104 	int ofs;
105 	int mode;
106 
107 	if (flow_type & IRQF_TRIGGER_PROBE)
108 		return 0;
109 	switch (flow_type & IRQF_TRIGGER_MASK) {
110 	case IRQF_TRIGGER_RISING:	mode = TXx9_IRCR_UP;	break;
111 	case IRQF_TRIGGER_FALLING:	mode = TXx9_IRCR_DOWN;	break;
112 	case IRQF_TRIGGER_HIGH: mode = TXx9_IRCR_HIGH;	break;
113 	case IRQF_TRIGGER_LOW:	mode = TXx9_IRCR_LOW;	break;
114 	default:
115 		return -EINVAL;
116 	}
117 	crp = &txx9_ircptr->cr[(unsigned int)irq_nr / 8];
118 	cr = __raw_readl(crp);
119 	ofs = (irq_nr & (8 - 1)) * 2;
120 	cr &= ~(0x3 << ofs);
121 	cr |= (mode & 0x3) << ofs;
122 	__raw_writel(cr, crp);
123 	txx9irq[irq_nr].mode = mode;
124 	return 0;
125 }
126 
127 static struct irq_chip txx9_irq_chip = {
128 	.name		= "TXX9",
129 	.irq_ack	= txx9_irq_mask_ack,
130 	.irq_mask	= txx9_irq_mask,
131 	.irq_mask_ack	= txx9_irq_mask_ack,
132 	.irq_unmask	= txx9_irq_unmask,
133 	.irq_set_type	= txx9_irq_set_type,
134 };
135 
136 void __init txx9_irq_init(unsigned long baseaddr)
137 {
138 	int i;
139 
140 	txx9_ircptr = ioremap(baseaddr, sizeof(struct txx9_irc_reg));
141 	for (i = 0; i < TXx9_MAX_IR; i++) {
142 		txx9irq[i].level = 4; /* middle level */
143 		txx9irq[i].mode = TXx9_IRCR_LOW;
144 		irq_set_chip_and_handler(TXX9_IRQ_BASE + i, &txx9_irq_chip,
145 					 handle_level_irq);
146 	}
147 
148 	/* mask all IRC interrupts */
149 	__raw_writel(0, &txx9_ircptr->imr);
150 	for (i = 0; i < 8; i++)
151 		__raw_writel(0, &txx9_ircptr->ilr[i]);
152 	/* setup IRC interrupt mode (Low Active) */
153 	for (i = 0; i < 2; i++)
154 		__raw_writel(0, &txx9_ircptr->cr[i]);
155 	/* enable interrupt control */
156 	__raw_writel(TXx9_IRCER_ICE, &txx9_ircptr->cer);
157 	__raw_writel(irc_elevel, &txx9_ircptr->imr);
158 }
159 
160 int __init txx9_irq_set_pri(int irc_irq, int new_pri)
161 {
162 	int old_pri;
163 
164 	if ((unsigned int)irc_irq >= TXx9_MAX_IR)
165 		return 0;
166 	old_pri = txx9irq[irc_irq].level;
167 	txx9irq[irc_irq].level = new_pri;
168 	return old_pri;
169 }
170 
171 int txx9_irq(void)
172 {
173 	u32 csr = __raw_readl(&txx9_ircptr->csr);
174 
175 	if (likely(!(csr & TXx9_IRCSR_IF)))
176 		return TXX9_IRQ_BASE + (csr & (TXx9_MAX_IR - 1));
177 	return -1;
178 }
179