1 /*
2 * arch/sh/boards/mach-x3proto/gpio.c
3 *
4 * Renesas SH-X3 Prototype Baseboard GPIO Support.
5 *
6 * Copyright (C) 2010 Paul Mundt
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/gpio.h>
17 #include <linux/irq.h>
18 #include <linux/kernel.h>
19 #include <linux/spinlock.h>
20 #include <linux/io.h>
21 #include <mach/ilsel.h>
22 #include <mach/hardware.h>
23
24 #define KEYCTLR 0xb81c0000
25 #define KEYOUTR 0xb81c0002
26 #define KEYDETR 0xb81c0004
27
28 static DEFINE_SPINLOCK(x3proto_gpio_lock);
29 static unsigned int x3proto_gpio_irq_map[NR_BASEBOARD_GPIOS] = { 0, };
30
x3proto_gpio_direction_input(struct gpio_chip * chip,unsigned gpio)31 static int x3proto_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
32 {
33 unsigned long flags;
34 unsigned int data;
35
36 spin_lock_irqsave(&x3proto_gpio_lock, flags);
37 data = __raw_readw(KEYCTLR);
38 data |= (1 << gpio);
39 __raw_writew(data, KEYCTLR);
40 spin_unlock_irqrestore(&x3proto_gpio_lock, flags);
41
42 return 0;
43 }
44
x3proto_gpio_get(struct gpio_chip * chip,unsigned gpio)45 static int x3proto_gpio_get(struct gpio_chip *chip, unsigned gpio)
46 {
47 return !!(__raw_readw(KEYDETR) & (1 << gpio));
48 }
49
x3proto_gpio_to_irq(struct gpio_chip * chip,unsigned gpio)50 static int x3proto_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
51 {
52 return x3proto_gpio_irq_map[gpio];
53 }
54
x3proto_gpio_irq_handler(unsigned int irq,struct irq_desc * desc)55 static void x3proto_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
56 {
57 struct irq_data *data = irq_get_irq_data(irq);
58 struct irq_chip *chip = irq_data_get_irq_chip(data);
59 unsigned long mask;
60 int pin;
61
62 chip->irq_mask_ack(data);
63
64 mask = __raw_readw(KEYDETR);
65
66 for_each_set_bit(pin, &mask, NR_BASEBOARD_GPIOS)
67 generic_handle_irq(x3proto_gpio_to_irq(NULL, pin));
68
69 chip->irq_unmask(data);
70 }
71
72 struct gpio_chip x3proto_gpio_chip = {
73 .label = "x3proto-gpio",
74 .direction_input = x3proto_gpio_direction_input,
75 .get = x3proto_gpio_get,
76 .to_irq = x3proto_gpio_to_irq,
77 .base = -1,
78 .ngpio = NR_BASEBOARD_GPIOS,
79 };
80
x3proto_gpio_setup(void)81 int __init x3proto_gpio_setup(void)
82 {
83 int ilsel;
84 int ret, i;
85
86 ilsel = ilsel_enable(ILSEL_KEY);
87 if (unlikely(ilsel < 0))
88 return ilsel;
89
90 ret = gpiochip_add(&x3proto_gpio_chip);
91 if (unlikely(ret))
92 goto err_gpio;
93
94 for (i = 0; i < NR_BASEBOARD_GPIOS; i++) {
95 unsigned long flags;
96 int irq = create_irq();
97
98 if (unlikely(irq < 0)) {
99 ret = -EINVAL;
100 goto err_irq;
101 }
102
103 spin_lock_irqsave(&x3proto_gpio_lock, flags);
104 x3proto_gpio_irq_map[i] = irq;
105 irq_set_chip_and_handler_name(irq, &dummy_irq_chip,
106 handle_simple_irq, "gpio");
107 spin_unlock_irqrestore(&x3proto_gpio_lock, flags);
108 }
109
110 pr_info("registering '%s' support, handling GPIOs %u -> %u, "
111 "bound to IRQ %u\n",
112 x3proto_gpio_chip.label, x3proto_gpio_chip.base,
113 x3proto_gpio_chip.base + x3proto_gpio_chip.ngpio,
114 ilsel);
115
116 irq_set_chained_handler(ilsel, x3proto_gpio_irq_handler);
117 irq_set_irq_wake(ilsel, 1);
118
119 return 0;
120
121 err_irq:
122 for (; i >= 0; --i)
123 if (x3proto_gpio_irq_map[i])
124 destroy_irq(x3proto_gpio_irq_map[i]);
125
126 ret = gpiochip_remove(&x3proto_gpio_chip);
127 if (unlikely(ret))
128 pr_err("Failed deregistering GPIO\n");
129
130 err_gpio:
131 synchronize_irq(ilsel);
132
133 ilsel_disable(ILSEL_KEY);
134
135 return ret;
136 }
137