1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/sh/boards/mach-x3proto/gpio.c
4 *
5 * Renesas SH-X3 Prototype Baseboard GPIO Support.
6 *
7 * Copyright (C) 2010 - 2012 Paul Mundt
8 */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/gpio/driver.h>
14 #include <linux/irq.h>
15 #include <linux/kernel.h>
16 #include <linux/spinlock.h>
17 #include <linux/irqdomain.h>
18 #include <linux/io.h>
19 #include <mach/ilsel.h>
20 #include <mach/hardware.h>
21
22 #define KEYCTLR 0xb81c0000
23 #define KEYOUTR 0xb81c0002
24 #define KEYDETR 0xb81c0004
25
26 static DEFINE_SPINLOCK(x3proto_gpio_lock);
27 static struct irq_domain *x3proto_irq_domain;
28
x3proto_gpio_direction_input(struct gpio_chip * chip,unsigned gpio)29 static int x3proto_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
30 {
31 unsigned long flags;
32 unsigned int data;
33
34 spin_lock_irqsave(&x3proto_gpio_lock, flags);
35 data = __raw_readw(KEYCTLR);
36 data |= (1 << gpio);
37 __raw_writew(data, KEYCTLR);
38 spin_unlock_irqrestore(&x3proto_gpio_lock, flags);
39
40 return 0;
41 }
42
x3proto_gpio_get(struct gpio_chip * chip,unsigned gpio)43 static int x3proto_gpio_get(struct gpio_chip *chip, unsigned gpio)
44 {
45 return !!(__raw_readw(KEYDETR) & (1 << gpio));
46 }
47
x3proto_gpio_to_irq(struct gpio_chip * chip,unsigned gpio)48 static int x3proto_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
49 {
50 int virq;
51
52 if (gpio < chip->ngpio)
53 virq = irq_create_mapping(x3proto_irq_domain, gpio);
54 else
55 virq = -ENXIO;
56
57 return virq;
58 }
59
x3proto_gpio_irq_handler(struct irq_desc * desc)60 static void x3proto_gpio_irq_handler(struct irq_desc *desc)
61 {
62 struct irq_data *data = irq_desc_get_irq_data(desc);
63 struct irq_chip *chip = irq_data_get_irq_chip(data);
64 unsigned long mask;
65 int pin;
66
67 chip->irq_mask_ack(data);
68
69 mask = __raw_readw(KEYDETR);
70 for_each_set_bit(pin, &mask, NR_BASEBOARD_GPIOS)
71 generic_handle_domain_irq(x3proto_irq_domain, pin);
72
73 chip->irq_unmask(data);
74 }
75
76 struct gpio_chip x3proto_gpio_chip = {
77 .label = "x3proto-gpio",
78 .direction_input = x3proto_gpio_direction_input,
79 .get = x3proto_gpio_get,
80 .to_irq = x3proto_gpio_to_irq,
81 .base = -1,
82 .ngpio = NR_BASEBOARD_GPIOS,
83 };
84
x3proto_gpio_irq_map(struct irq_domain * domain,unsigned int virq,irq_hw_number_t hwirq)85 static int x3proto_gpio_irq_map(struct irq_domain *domain, unsigned int virq,
86 irq_hw_number_t hwirq)
87 {
88 irq_set_chip_and_handler_name(virq, &dummy_irq_chip, handle_simple_irq,
89 "gpio");
90
91 return 0;
92 }
93
94 static struct irq_domain_ops x3proto_gpio_irq_ops = {
95 .map = x3proto_gpio_irq_map,
96 .xlate = irq_domain_xlate_twocell,
97 };
98
x3proto_gpio_setup(void)99 int __init x3proto_gpio_setup(void)
100 {
101 int ilsel, ret;
102
103 ilsel = ilsel_enable(ILSEL_KEY);
104 if (unlikely(ilsel < 0))
105 return ilsel;
106
107 ret = gpiochip_add_data(&x3proto_gpio_chip, NULL);
108 if (unlikely(ret))
109 goto err_gpio;
110
111 x3proto_irq_domain = irq_domain_add_linear(NULL, NR_BASEBOARD_GPIOS,
112 &x3proto_gpio_irq_ops, NULL);
113 if (unlikely(!x3proto_irq_domain))
114 goto err_irq;
115
116 pr_info("registering '%s' support, handling GPIOs %u -> %u, "
117 "bound to IRQ %u\n",
118 x3proto_gpio_chip.label, x3proto_gpio_chip.base,
119 x3proto_gpio_chip.base + x3proto_gpio_chip.ngpio,
120 ilsel);
121
122 irq_set_chained_handler(ilsel, x3proto_gpio_irq_handler);
123 irq_set_irq_wake(ilsel, 1);
124
125 return 0;
126
127 err_irq:
128 gpiochip_remove(&x3proto_gpio_chip);
129 ret = 0;
130 err_gpio:
131 synchronize_irq(ilsel);
132
133 ilsel_disable(ILSEL_KEY);
134
135 return ret;
136 }
137