summaryrefslogtreecommitdiffstats
path: root/arch/xtensa/variants/s6000/gpio.c
blob: 380a70fff756b3e561200126bb9b5a87b671c866 (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
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
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
/*
 * s6000 gpio driver
 *
 * Copyright (c) 2009 emlix GmbH
 * Authors:	Oskar Schirmer <os@emlix.com>
 *		Johannes Weiner <jw@emlix.com>
 *		Daniel Gloeckner <dg@emlix.com>
 */
#include <linux/bitops.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/gpio.h>

#include <variant/hardware.h>

#define IRQ_BASE XTENSA_NR_IRQS

#define S6_GPIO_DATA		0x000
#define S6_GPIO_IS		0x404
#define S6_GPIO_IBE		0x408
#define S6_GPIO_IEV		0x40C
#define S6_GPIO_IE		0x410
#define S6_GPIO_RIS		0x414
#define S6_GPIO_MIS		0x418
#define S6_GPIO_IC		0x41C
#define S6_GPIO_AFSEL		0x420
#define S6_GPIO_DIR		0x800
#define S6_GPIO_BANK(nr)	((nr) * 0x1000)
#define S6_GPIO_MASK(nr)	(4 << (nr))
#define S6_GPIO_OFFSET(nr) \
		(S6_GPIO_BANK((nr) >> 3) + S6_GPIO_MASK((nr) & 7))

static int direction_input(struct gpio_chip *chip, unsigned int off)
{
	writeb(0, S6_REG_GPIO + S6_GPIO_DIR + S6_GPIO_OFFSET(off));
	return 0;
}

static int get(struct gpio_chip *chip, unsigned int off)
{
	return readb(S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
}

static int direction_output(struct gpio_chip *chip, unsigned int off, int val)
{
	unsigned rel = S6_GPIO_OFFSET(off);
	writeb(~0, S6_REG_GPIO + S6_GPIO_DIR + rel);
	writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + rel);
	return 0;
}

static void set(struct gpio_chip *chip, unsigned int off, int val)
{
	writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
}

static int to_irq(struct gpio_chip *chip, unsigned offset)
{
	if (offset < 8)
		return offset + IRQ_BASE;
	return -EINVAL;
}

static struct gpio_chip gpiochip = {
	.owner = THIS_MODULE,
	.direction_input = direction_input,
	.get = get,
	.direction_output = direction_output,
	.set = set,
	.to_irq = to_irq,
	.base = 0,
	.ngpio = 24,
	.can_sleep = 0, /* no blocking io needed */
	.exported = 0, /* no exporting to userspace */
};

int s6_gpio_init(u32 afsel)
{
	writeb(afsel, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_AFSEL);
	writeb(afsel >> 8, S6_REG_GPIO + S6_GPIO_BANK(1) + S6_GPIO_AFSEL);
	writeb(afsel >> 16, S6_REG_GPIO + S6_GPIO_BANK(2) + S6_GPIO_AFSEL);
	return gpiochip_add(&gpiochip);
}

static void ack(unsigned int irq)
{
	writeb(1 << (irq - IRQ_BASE), S6_REG_GPIO + S6_GPIO_IC);
}

static void mask(unsigned int irq)
{
	u8 r = readb(S6_REG_GPIO + S6_GPIO_IE);
	r &= ~(1 << (irq - IRQ_BASE));
	writeb(r, S6_REG_GPIO + S6_GPIO_IE);
}

static void unmask(unsigned int irq)
{
	u8 m = readb(S6_REG_GPIO + S6_GPIO_IE);
	m |= 1 << (irq - IRQ_BASE);
	writeb(m, S6_REG_GPIO + S6_GPIO_IE);
}

static int set_type(unsigned int irq, unsigned int type)
{
	const u8 m = 1 << (irq - IRQ_BASE);
	irq_flow_handler_t handler;
	struct irq_desc *desc;
	u8 reg;

	if (type == IRQ_TYPE_PROBE) {
		if ((readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_AFSEL) & m)
		    || (readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IE) & m)
		    || readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_DIR
			      + S6_GPIO_MASK(irq - IRQ_BASE)))
			return 0;
		type = IRQ_TYPE_EDGE_BOTH;
	}

	reg = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IS);
	if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) {
		reg |= m;
		handler = handle_level_irq;
	} else {
		reg &= ~m;
		handler = handle_edge_irq;
	}
	writeb(reg, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IS);
	desc = irq_to_desc(irq);
	desc->handle_irq = handler;

	reg = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IEV);
	if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING))
		reg |= m;
	else
		reg &= ~m;
	writeb(reg, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IEV);

	reg = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IBE);
	if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
		reg |= m;
	else
		reg &= ~m;
	writeb(reg, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IBE);
	return 0;
}

static struct irq_chip gpioirqs = {
	.name = "GPIO",
	.ack = ack,
	.mask = mask,
	.unmask = unmask,
	.set_type = set_type,
};

static u8 demux_masks[4];

static void demux_irqs(unsigned int irq, struct irq_desc *desc)
{
	u8 *mask = get_irq_desc_data(desc);
	u8 pending;
	int cirq;

	desc->chip->mask(irq);
	desc->chip->ack(irq);
	pending = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_MIS) & *mask;
	cirq = IRQ_BASE - 1;
	while (pending) {
		int n = ffs(pending);
		cirq += n;
		pending >>= n;
		generic_handle_irq(cirq);
	}
	desc->chip->unmask(irq);
}

extern const signed char *platform_irq_mappings[XTENSA_NR_IRQS];

void __init variant_init_irq(void)
{
	int irq, n;
	writeb(0, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IE);
	for (irq = n = 0; irq < XTENSA_NR_IRQS; irq++) {
		const signed char *mapping = platform_irq_mappings[irq];
		int alone = 1;
		u8 mask;
		if (!mapping)
			continue;
		for(mask = 0; *mapping != -1; mapping++)
			switch (*mapping) {
			case S6_INTC_GPIO(0):
				mask |= 1 << 0;
				break;
			case S6_INTC_GPIO(1):
				mask |= 1 << 1;
				break;
			case S6_INTC_GPIO(2):
				mask |= 1 << 2;
				break;
			case S6_INTC_GPIO(3):
				mask |= 0x1f << 3;
				break;
			default:
				alone = 0;
			}
		if (mask) {
			int cirq, i;
			if (!alone) {
				printk(KERN_ERR "chained irq chips can't share"
					" parent irq %i\n", irq);
				continue;
			}
			demux_masks[n] = mask;
			cirq = IRQ_BASE - 1;
			do {
				i = ffs(mask);
				cirq += i;
				mask >>= i;
				set_irq_chip(cirq, &gpioirqs);
				set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
			} while (mask);
			set_irq_data(irq, demux_masks + n);
			set_irq_chained_handler(irq, demux_irqs);
			if (++n == ARRAY_SIZE(demux_masks))
				break;
		}
	}
}
OpenPOWER on IntegriCloud