summaryrefslogtreecommitdiff
path: root/arch/mips/alchemy/devboards/bcsr.c
blob: c52af8821da071f5fe49117ddb6f7f2652756c00 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/*
 * bcsr.h -- Db1xxx/Pb1xxx Devboard CPLD registers ("BCSR") abstraction.
 *
 * All Alchemy development boards (except, of course, the weird PB1000)
 * have a few registers in a CPLD with standardised layout; they mostly
 * only differ in base address.
 * All registers are 16bits wide with 32bit spacing.
 */

#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <asm/addrspace.h>
#include <asm/io.h>
#include <asm/mach-db1x00/bcsr.h>

static struct bcsr_reg {
	void __iomem *raddr;
	spinlock_t lock;
} bcsr_regs[BCSR_CNT];

static void __iomem *bcsr_virt;	/* KSEG1 addr of BCSR base */
static int bcsr_csc_base;	/* linux-irq of first cascaded irq */

void __init bcsr_init(unsigned long bcsr1_phys, unsigned long bcsr2_phys)
{
	int i;

	bcsr1_phys = KSEG1ADDR(CPHYSADDR(bcsr1_phys));
	bcsr2_phys = KSEG1ADDR(CPHYSADDR(bcsr2_phys));

	bcsr_virt = (void __iomem *)bcsr1_phys;

	for (i = 0; i < BCSR_CNT; i++) {
		if (i >= BCSR_HEXLEDS)
			bcsr_regs[i].raddr = (void __iomem *)bcsr2_phys +
					(0x04 * (i - BCSR_HEXLEDS));
		else
			bcsr_regs[i].raddr = (void __iomem *)bcsr1_phys +
					(0x04 * i);

		spin_lock_init(&bcsr_regs[i].lock);
	}
}

unsigned short bcsr_read(enum bcsr_id reg)
{
	unsigned short r;
	unsigned long flags;

	spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
	r = __raw_readw(bcsr_regs[reg].raddr);
	spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
	return r;
}
EXPORT_SYMBOL_GPL(bcsr_read);

void bcsr_write(enum bcsr_id reg, unsigned short val)
{
	unsigned long flags;

	spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
	__raw_writew(val, bcsr_regs[reg].raddr);
	wmb();
	spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
}
EXPORT_SYMBOL_GPL(bcsr_write);

void bcsr_mod(enum bcsr_id reg, unsigned short clr, unsigned short set)
{
	unsigned short r;
	unsigned long flags;

	spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
	r = __raw_readw(bcsr_regs[reg].raddr);
	r &= ~clr;
	r |= set;
	__raw_writew(r, bcsr_regs[reg].raddr);
	wmb();
	spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
}
EXPORT_SYMBOL_GPL(bcsr_mod);

/*
 * DB1200/PB1200 CPLD IRQ muxer
 */
static void bcsr_csc_handler(unsigned int irq, struct irq_desc *d)
{
	unsigned short bisr = __raw_readw(bcsr_virt + BCSR_REG_INTSTAT);

	for ( ; bisr; bisr &= bisr - 1)
		generic_handle_irq(bcsr_csc_base + __ffs(bisr));
}

/* NOTE: both the enable and mask bits must be cleared, otherwise the
 * CPLD generates tons of spurious interrupts (at least on my DB1200).
 *	-- mlau
 */
static void bcsr_irq_mask(unsigned int irq_nr)
{
	unsigned short v = 1 << (irq_nr - bcsr_csc_base);
	__raw_writew(v, bcsr_virt + BCSR_REG_INTCLR);
	__raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR);
	wmb();
}

static void bcsr_irq_maskack(unsigned int irq_nr)
{
	unsigned short v = 1 << (irq_nr - bcsr_csc_base);
	__raw_writew(v, bcsr_virt + BCSR_REG_INTCLR);
	__raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR);
	__raw_writew(v, bcsr_virt + BCSR_REG_INTSTAT);	/* ack */
	wmb();
}

static void bcsr_irq_unmask(unsigned int irq_nr)
{
	unsigned short v = 1 << (irq_nr - bcsr_csc_base);
	__raw_writew(v, bcsr_virt + BCSR_REG_INTSET);
	__raw_writew(v, bcsr_virt + BCSR_REG_MASKSET);
	wmb();
}

static struct irq_chip bcsr_irq_type = {
	.name		= "CPLD",
	.mask		= bcsr_irq_mask,
	.mask_ack	= bcsr_irq_maskack,
	.unmask		= bcsr_irq_unmask,
};

void __init bcsr_init_irq(int csc_start, int csc_end, int hook_irq)
{
	unsigned int irq;

	/* mask & disable & ack all */
	__raw_writew(0xffff, bcsr_virt + BCSR_REG_INTCLR);
	__raw_writew(0xffff, bcsr_virt + BCSR_REG_MASKCLR);
	__raw_writew(0xffff, bcsr_virt + BCSR_REG_INTSTAT);
	wmb();

	bcsr_csc_base = csc_start;

	for (irq = csc_start; irq <= csc_end; irq++)
		set_irq_chip_and_handler_name(irq, &bcsr_irq_type,
			handle_level_irq, "level");

	set_irq_chained_handler(hook_irq, bcsr_csc_handler);
}