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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
/*
* arch/arm/mach-orion5x/irq.c
*
* Core IRQ functions for Marvell Orion System On Chip
*
* Maintainer: Tzachi Perelstein <tzachi@marvell.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <asm/arch/orion5x.h>
#include <asm/plat-orion/irq.h>
#include "common.h"
/*****************************************************************************
* Orion GPIO IRQ
*
* GPIO_IN_POL register controlls whether GPIO_DATA_IN will hold the same
* value of the line or the opposite value.
*
* Level IRQ handlers: DATA_IN is used directly as cause register.
* Interrupt are masked by LEVEL_MASK registers.
* Edge IRQ handlers: Change in DATA_IN are latched in EDGE_CAUSE.
* Interrupt are masked by EDGE_MASK registers.
* Both-edge handlers: Similar to regular Edge handlers, but also swaps
* the polarity to catch the next line transaction.
* This is a race condition that might not perfectly
* work on some use cases.
*
* Every eight GPIO lines are grouped (OR'ed) before going up to main
* cause register.
*
* EDGE cause mask
* data-in /--------| |-----| |----\
* -----| |----- ---- to main cause reg
* X \----------------| |----/
* polarity LEVEL mask
*
****************************************************************************/
static void orion5x_gpio_irq_ack(u32 irq)
{
int pin = irq_to_gpio(irq);
if (irq_desc[irq].status & IRQ_LEVEL)
/*
* Mask bit for level interrupt
*/
orion5x_clrbits(GPIO_LEVEL_MASK, 1 << pin);
else
/*
* Clear casue bit for egde interrupt
*/
orion5x_clrbits(GPIO_EDGE_CAUSE, 1 << pin);
}
static void orion5x_gpio_irq_mask(u32 irq)
{
int pin = irq_to_gpio(irq);
if (irq_desc[irq].status & IRQ_LEVEL)
orion5x_clrbits(GPIO_LEVEL_MASK, 1 << pin);
else
orion5x_clrbits(GPIO_EDGE_MASK, 1 << pin);
}
static void orion5x_gpio_irq_unmask(u32 irq)
{
int pin = irq_to_gpio(irq);
if (irq_desc[irq].status & IRQ_LEVEL)
orion5x_setbits(GPIO_LEVEL_MASK, 1 << pin);
else
orion5x_setbits(GPIO_EDGE_MASK, 1 << pin);
}
static int orion5x_gpio_set_irq_type(u32 irq, u32 type)
{
int pin = irq_to_gpio(irq);
struct irq_desc *desc;
if ((orion5x_read(GPIO_IO_CONF) & (1 << pin)) == 0) {
printk(KERN_ERR "orion5x_gpio_set_irq_type failed "
"(irq %d, pin %d).\n", irq, pin);
return -EINVAL;
}
desc = irq_desc + irq;
switch (type) {
case IRQT_HIGH:
desc->handle_irq = handle_level_irq;
desc->status |= IRQ_LEVEL;
orion5x_clrbits(GPIO_IN_POL, (1 << pin));
break;
case IRQT_LOW:
desc->handle_irq = handle_level_irq;
desc->status |= IRQ_LEVEL;
orion5x_setbits(GPIO_IN_POL, (1 << pin));
break;
case IRQT_RISING:
desc->handle_irq = handle_edge_irq;
desc->status &= ~IRQ_LEVEL;
orion5x_clrbits(GPIO_IN_POL, (1 << pin));
break;
case IRQT_FALLING:
desc->handle_irq = handle_edge_irq;
desc->status &= ~IRQ_LEVEL;
orion5x_setbits(GPIO_IN_POL, (1 << pin));
break;
case IRQT_BOTHEDGE:
desc->handle_irq = handle_edge_irq;
desc->status &= ~IRQ_LEVEL;
/*
* set initial polarity based on current input level
*/
if ((orion5x_read(GPIO_IN_POL) ^ orion5x_read(GPIO_DATA_IN))
& (1 << pin))
orion5x_setbits(GPIO_IN_POL, (1 << pin)); /* falling */
else
orion5x_clrbits(GPIO_IN_POL, (1 << pin)); /* rising */
break;
default:
printk(KERN_ERR "failed to set irq=%d (type=%d)\n", irq, type);
return -EINVAL;
}
desc->status &= ~IRQ_TYPE_SENSE_MASK;
desc->status |= type & IRQ_TYPE_SENSE_MASK;
return 0;
}
static struct irq_chip orion5x_gpio_irq_chip = {
.name = "Orion-IRQ-GPIO",
.ack = orion5x_gpio_irq_ack,
.mask = orion5x_gpio_irq_mask,
.unmask = orion5x_gpio_irq_unmask,
.set_type = orion5x_gpio_set_irq_type,
};
static void orion5x_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
{
u32 cause, offs, pin;
BUG_ON(irq < IRQ_ORION5X_GPIO_0_7 || irq > IRQ_ORION5X_GPIO_24_31);
offs = (irq - IRQ_ORION5X_GPIO_0_7) * 8;
cause = (orion5x_read(GPIO_DATA_IN) & orion5x_read(GPIO_LEVEL_MASK)) |
(orion5x_read(GPIO_EDGE_CAUSE) & orion5x_read(GPIO_EDGE_MASK));
for (pin = offs; pin < offs + 8; pin++) {
if (cause & (1 << pin)) {
irq = gpio_to_irq(pin);
desc = irq_desc + irq;
if ((desc->status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE) {
/* Swap polarity (race with GPIO line) */
u32 polarity = orion5x_read(GPIO_IN_POL);
polarity ^= 1 << pin;
orion5x_write(GPIO_IN_POL, polarity);
}
desc_handle_irq(irq, desc);
}
}
}
static void __init orion5x_init_gpio_irq(void)
{
int i;
struct irq_desc *desc;
/*
* Mask and clear GPIO IRQ interrupts
*/
orion5x_write(GPIO_LEVEL_MASK, 0x0);
orion5x_write(GPIO_EDGE_MASK, 0x0);
orion5x_write(GPIO_EDGE_CAUSE, 0x0);
/*
* Register chained level handlers for GPIO IRQs by default.
* User can use set_type() if he wants to use edge types handlers.
*/
for (i = IRQ_ORION5X_GPIO_START; i < NR_IRQS; i++) {
set_irq_chip(i, &orion5x_gpio_irq_chip);
set_irq_handler(i, handle_level_irq);
desc = irq_desc + i;
desc->status |= IRQ_LEVEL;
set_irq_flags(i, IRQF_VALID);
}
set_irq_chained_handler(IRQ_ORION5X_GPIO_0_7, orion5x_gpio_irq_handler);
set_irq_chained_handler(IRQ_ORION5X_GPIO_8_15, orion5x_gpio_irq_handler);
set_irq_chained_handler(IRQ_ORION5X_GPIO_16_23, orion5x_gpio_irq_handler);
set_irq_chained_handler(IRQ_ORION5X_GPIO_24_31, orion5x_gpio_irq_handler);
}
/*****************************************************************************
* Orion Main IRQ
****************************************************************************/
static void __init orion5x_init_main_irq(void)
{
orion_irq_init(0, (void __iomem *)MAIN_IRQ_MASK);
}
void __init orion5x_init_irq(void)
{
orion5x_init_main_irq();
orion5x_init_gpio_irq();
}
|
