xref: /openbmc/linux/arch/mips/kernel/irq_txx9.c (revision 588b48ca)
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 #ifdef CONFIG_CPU_TX39XX
76 	/* update IRCSR */
77 	__raw_writel(0, &txx9_ircptr->imr);
78 	__raw_writel(irc_elevel, &txx9_ircptr->imr);
79 #endif
80 }
81 
82 static inline void txx9_irq_mask(struct irq_data *d)
83 {
84 	unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
85 	u32 __iomem *ilrp = &txx9_ircptr->ilr[(irq_nr % 16) / 2];
86 	int ofs = irq_nr / 16 * 16 + (irq_nr & 1) * 8;
87 
88 	__raw_writel((__raw_readl(ilrp) & ~(0xff << ofs))
89 		     | (irc_dlevel << ofs),
90 		     ilrp);
91 #ifdef CONFIG_CPU_TX39XX
92 	/* update IRCSR */
93 	__raw_writel(0, &txx9_ircptr->imr);
94 	__raw_writel(irc_elevel, &txx9_ircptr->imr);
95 	/* flush write buffer */
96 	__raw_readl(&txx9_ircptr->ssr);
97 #else
98 	mmiowb();
99 #endif
100 }
101 
102 static void txx9_irq_mask_ack(struct irq_data *d)
103 {
104 	unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
105 
106 	txx9_irq_mask(d);
107 	/* clear edge detection */
108 	if (unlikely(TXx9_IRCR_EDGE(txx9irq[irq_nr].mode)))
109 		__raw_writel(TXx9_IRSCR_EIClrE | irq_nr, &txx9_ircptr->scr);
110 }
111 
112 static int txx9_irq_set_type(struct irq_data *d, unsigned int flow_type)
113 {
114 	unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
115 	u32 cr;
116 	u32 __iomem *crp;
117 	int ofs;
118 	int mode;
119 
120 	if (flow_type & IRQF_TRIGGER_PROBE)
121 		return 0;
122 	switch (flow_type & IRQF_TRIGGER_MASK) {
123 	case IRQF_TRIGGER_RISING:	mode = TXx9_IRCR_UP;	break;
124 	case IRQF_TRIGGER_FALLING:	mode = TXx9_IRCR_DOWN;	break;
125 	case IRQF_TRIGGER_HIGH: mode = TXx9_IRCR_HIGH;	break;
126 	case IRQF_TRIGGER_LOW:	mode = TXx9_IRCR_LOW;	break;
127 	default:
128 		return -EINVAL;
129 	}
130 	crp = &txx9_ircptr->cr[(unsigned int)irq_nr / 8];
131 	cr = __raw_readl(crp);
132 	ofs = (irq_nr & (8 - 1)) * 2;
133 	cr &= ~(0x3 << ofs);
134 	cr |= (mode & 0x3) << ofs;
135 	__raw_writel(cr, crp);
136 	txx9irq[irq_nr].mode = mode;
137 	return 0;
138 }
139 
140 static struct irq_chip txx9_irq_chip = {
141 	.name		= "TXX9",
142 	.irq_ack	= txx9_irq_mask_ack,
143 	.irq_mask	= txx9_irq_mask,
144 	.irq_mask_ack	= txx9_irq_mask_ack,
145 	.irq_unmask	= txx9_irq_unmask,
146 	.irq_set_type	= txx9_irq_set_type,
147 };
148 
149 void __init txx9_irq_init(unsigned long baseaddr)
150 {
151 	int i;
152 
153 	txx9_ircptr = ioremap(baseaddr, sizeof(struct txx9_irc_reg));
154 	for (i = 0; i < TXx9_MAX_IR; i++) {
155 		txx9irq[i].level = 4; /* middle level */
156 		txx9irq[i].mode = TXx9_IRCR_LOW;
157 		irq_set_chip_and_handler(TXX9_IRQ_BASE + i, &txx9_irq_chip,
158 					 handle_level_irq);
159 	}
160 
161 	/* mask all IRC interrupts */
162 	__raw_writel(0, &txx9_ircptr->imr);
163 	for (i = 0; i < 8; i++)
164 		__raw_writel(0, &txx9_ircptr->ilr[i]);
165 	/* setup IRC interrupt mode (Low Active) */
166 	for (i = 0; i < 2; i++)
167 		__raw_writel(0, &txx9_ircptr->cr[i]);
168 	/* enable interrupt control */
169 	__raw_writel(TXx9_IRCER_ICE, &txx9_ircptr->cer);
170 	__raw_writel(irc_elevel, &txx9_ircptr->imr);
171 }
172 
173 int __init txx9_irq_set_pri(int irc_irq, int new_pri)
174 {
175 	int old_pri;
176 
177 	if ((unsigned int)irc_irq >= TXx9_MAX_IR)
178 		return 0;
179 	old_pri = txx9irq[irc_irq].level;
180 	txx9irq[irc_irq].level = new_pri;
181 	return old_pri;
182 }
183 
184 int txx9_irq(void)
185 {
186 	u32 csr = __raw_readl(&txx9_ircptr->csr);
187 
188 	if (likely(!(csr & TXx9_IRCSR_IF)))
189 		return TXX9_IRQ_BASE + (csr & (TXx9_MAX_IR - 1));
190 	return -1;
191 }
192