tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * bcsr.h -- Db1xxx/Pb1xxx Devboard CPLD registers ("BCSR") abstraction.
3 *
4 * All Alchemy development boards (except, of course, the weird PB1000)
5 * have a few registers in a CPLD with standardised layout; they mostly
6 * only differ in base address.
7 * All registers are 16bits wide with 32bit spacing.
8 */
9
10#include <linux/interrupt.h>
11#include <linux/irqchip/chained_irq.h>
12#include <linux/init.h>
13#include <linux/export.h>
14#include <linux/spinlock.h>
15#include <linux/irq.h>
16#include <asm/addrspace.h>
17#include <asm/io.h>
18#include <asm/mach-db1x00/bcsr.h>
19
20static struct bcsr_reg {
21 void __iomem *raddr;
22 spinlock_t lock;
23} bcsr_regs[BCSR_CNT];
24
25static void __iomem *bcsr_virt; /* KSEG1 addr of BCSR base */
26static int bcsr_csc_base; /* linux-irq of first cascaded irq */
27
28void __init bcsr_init(unsigned long bcsr1_phys, unsigned long bcsr2_phys)
29{
30 int i;
31
32 bcsr1_phys = KSEG1ADDR(CPHYSADDR(bcsr1_phys));
33 bcsr2_phys = KSEG1ADDR(CPHYSADDR(bcsr2_phys));
34
35 bcsr_virt = (void __iomem *)bcsr1_phys;
36
37 for (i = 0; i < BCSR_CNT; i++) {
38 if (i >= BCSR_HEXLEDS)
39 bcsr_regs[i].raddr = (void __iomem *)bcsr2_phys +
40 (0x04 * (i - BCSR_HEXLEDS));
41 else
42 bcsr_regs[i].raddr = (void __iomem *)bcsr1_phys +
43 (0x04 * i);
44
45 spin_lock_init(&bcsr_regs[i].lock);
46 }
47}
48
49unsigned short bcsr_read(enum bcsr_id reg)
50{
51 unsigned short r;
52 unsigned long flags;
53
54 spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
55 r = __raw_readw(bcsr_regs[reg].raddr);
56 spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
57 return r;
58}
59EXPORT_SYMBOL_GPL(bcsr_read);
60
61void bcsr_write(enum bcsr_id reg, unsigned short val)
62{
63 unsigned long flags;
64
65 spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
66 __raw_writew(val, bcsr_regs[reg].raddr);
67 wmb();
68 spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
69}
70EXPORT_SYMBOL_GPL(bcsr_write);
71
72void bcsr_mod(enum bcsr_id reg, unsigned short clr, unsigned short set)
73{
74 unsigned short r;
75 unsigned long flags;
76
77 spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
78 r = __raw_readw(bcsr_regs[reg].raddr);
79 r &= ~clr;
80 r |= set;
81 __raw_writew(r, bcsr_regs[reg].raddr);
82 wmb();
83 spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
84}
85EXPORT_SYMBOL_GPL(bcsr_mod);
86
87/*
88 * DB1200/PB1200 CPLD IRQ muxer
89 */
90static void bcsr_csc_handler(struct irq_desc *d)
91{
92 unsigned short bisr = __raw_readw(bcsr_virt + BCSR_REG_INTSTAT);
93 struct irq_chip *chip = irq_desc_get_chip(d);
94
95 chained_irq_enter(chip, d);
96 generic_handle_irq(bcsr_csc_base + __ffs(bisr));
97 chained_irq_exit(chip, d);
98}
99
100static void bcsr_irq_mask(struct irq_data *d)
101{
102 unsigned short v = 1 << (d->irq - bcsr_csc_base);
103 __raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR);
104 wmb();
105}
106
107static void bcsr_irq_maskack(struct irq_data *d)
108{
109 unsigned short v = 1 << (d->irq - bcsr_csc_base);
110 __raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR);
111 __raw_writew(v, bcsr_virt + BCSR_REG_INTSTAT); /* ack */
112 wmb();
113}
114
115static void bcsr_irq_unmask(struct irq_data *d)
116{
117 unsigned short v = 1 << (d->irq - bcsr_csc_base);
118 __raw_writew(v, bcsr_virt + BCSR_REG_MASKSET);
119 wmb();
120}
121
122static struct irq_chip bcsr_irq_type = {
123 .name = "CPLD",
124 .irq_mask = bcsr_irq_mask,
125 .irq_mask_ack = bcsr_irq_maskack,
126 .irq_unmask = bcsr_irq_unmask,
127};
128
129void __init bcsr_init_irq(int csc_start, int csc_end, int hook_irq)
130{
131 unsigned int irq;
132
133 /* mask & enable & ack all */
134 __raw_writew(0xffff, bcsr_virt + BCSR_REG_MASKCLR);
135 __raw_writew(0xffff, bcsr_virt + BCSR_REG_INTSET);
136 __raw_writew(0xffff, bcsr_virt + BCSR_REG_INTSTAT);
137 wmb();
138
139 bcsr_csc_base = csc_start;
140
141 for (irq = csc_start; irq <= csc_end; irq++)
142 irq_set_chip_and_handler_name(irq, &bcsr_irq_type,
143 handle_level_irq, "level");
144
145 irq_set_chained_handler(hook_irq, bcsr_csc_handler);
146}