1 /*
2 * arch/sh/boards/mach-x3proto/gpio.c
3 *
4 * Renesas SH-X3 Prototype Baseboard GPIO Support.
5 *
6 * Copyright (C) 2010 - 2012 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/driver.h>
17 #include <linux/irq.h>
18 #include <linux/kernel.h>
19 #include <linux/spinlock.h>
20 #include <linux/irqdomain.h>
21 #include <linux/io.h>
22 #include <mach/ilsel.h>
23 #include <mach/hardware.h>
24
25 #define KEYCTLR 0xb81c0000
26 #define KEYOUTR 0xb81c0002
27 #define KEYDETR 0xb81c0004
28
29 static DEFINE_SPINLOCK(x3proto_gpio_lock);
30 static struct irq_domain *x3proto_irq_domain;
31
x3proto_gpio_direction_input(struct gpio_chip * chip,unsigned gpio)32 static int x3proto_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
33 {
34 unsigned long flags;
35 unsigned int data;
36
37 spin_lock_irqsave(&x3proto_gpio_lock, flags);
38 data = __raw_readw(KEYCTLR);
39 data |= (1 << gpio);
40 __raw_writew(data, KEYCTLR);
41 spin_unlock_irqrestore(&x3proto_gpio_lock, flags);
42
43 return 0;
44 }
45
x3proto_gpio_get(struct gpio_chip * chip,unsigned gpio)46 static int x3proto_gpio_get(struct gpio_chip *chip, unsigned gpio)
47 {
48 return !!(__raw_readw(KEYDETR) & (1 << gpio));
49 }
50
x3proto_gpio_to_irq(struct gpio_chip * chip,unsigned gpio)51 static int x3proto_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
52 {
53 int virq;
54
55 if (gpio < chip->ngpio)
56 virq = irq_create_mapping(x3proto_irq_domain, gpio);
57 else
58 virq = -ENXIO;
59
60 return virq;
61 }
62
x3proto_gpio_irq_handler(struct irq_desc * desc)63 static void x3proto_gpio_irq_handler(struct irq_desc *desc)
64 {
65 struct irq_data *data = irq_desc_get_irq_data(desc);
66 struct irq_chip *chip = irq_data_get_irq_chip(data);
67 unsigned long mask;
68 int pin;
69
70 chip->irq_mask_ack(data);
71
72 mask = __raw_readw(KEYDETR);
73 for_each_set_bit(pin, &mask, NR_BASEBOARD_GPIOS)
74 generic_handle_irq(irq_linear_revmap(x3proto_irq_domain, pin));
75
76 chip->irq_unmask(data);
77 }
78
79 struct gpio_chip x3proto_gpio_chip = {
80 .label = "x3proto-gpio",
81 .direction_input = x3proto_gpio_direction_input,
82 .get = x3proto_gpio_get,
83 .to_irq = x3proto_gpio_to_irq,
84 .base = -1,
85 .ngpio = NR_BASEBOARD_GPIOS,
86 };
87
x3proto_gpio_irq_map(struct irq_domain * domain,unsigned int virq,irq_hw_number_t hwirq)88 static int x3proto_gpio_irq_map(struct irq_domain *domain, unsigned int virq,
89 irq_hw_number_t hwirq)
90 {
91 irq_set_chip_and_handler_name(virq, &dummy_irq_chip, handle_simple_irq,
92 "gpio");
93
94 return 0;
95 }
96
97 static struct irq_domain_ops x3proto_gpio_irq_ops = {
98 .map = x3proto_gpio_irq_map,
99 .xlate = irq_domain_xlate_twocell,
100 };
101
x3proto_gpio_setup(void)102 int __init x3proto_gpio_setup(void)
103 {
104 int ilsel, ret;
105
106 ilsel = ilsel_enable(ILSEL_KEY);
107 if (unlikely(ilsel < 0))
108 return ilsel;
109
110 ret = gpiochip_add_data(&x3proto_gpio_chip, NULL);
111 if (unlikely(ret))
112 goto err_gpio;
113
114 x3proto_irq_domain = irq_domain_add_linear(NULL, NR_BASEBOARD_GPIOS,
115 &x3proto_gpio_irq_ops, NULL);
116 if (unlikely(!x3proto_irq_domain))
117 goto err_irq;
118
119 pr_info("registering '%s' support, handling GPIOs %u -> %u, "
120 "bound to IRQ %u\n",
121 x3proto_gpio_chip.label, x3proto_gpio_chip.base,
122 x3proto_gpio_chip.base + x3proto_gpio_chip.ngpio,
123 ilsel);
124
125 irq_set_chained_handler(ilsel, x3proto_gpio_irq_handler);
126 irq_set_irq_wake(ilsel, 1);
127
128 return 0;
129
130 err_irq:
131 gpiochip_remove(&x3proto_gpio_chip);
132 ret = 0;
133 err_gpio:
134 synchronize_irq(ilsel);
135
136 ilsel_disable(ILSEL_KEY);
137
138 return ret;
139 }
140
