gpio.c revision c3323806a67c0c656e27956b7340e37ba6c6968b 
1/*
2 * SuperH Pin Function Controller GPIO driver.
3 *
4 * Copyright (C) 2008 Magnus Damm
5 * Copyright (C) 2009 - 2012 Paul Mundt
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License.  See the file "COPYING" in the main directory of this archive
9 * for more details.
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME " gpio: " fmt
13
14#include <linux/device.h>
15#include <linux/gpio.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/pinctrl/consumer.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21
22#include "core.h"
23
24struct sh_pfc_chip {
25	struct sh_pfc		*pfc;
26	struct gpio_chip	gpio_chip;
27};
28
29static struct sh_pfc_chip *gpio_to_pfc_chip(struct gpio_chip *gc)
30{
31	return container_of(gc, struct sh_pfc_chip, gpio_chip);
32}
33
34static struct sh_pfc *gpio_to_pfc(struct gpio_chip *gc)
35{
36	return gpio_to_pfc_chip(gc)->pfc;
37}
38
39static int sh_gpio_request(struct gpio_chip *gc, unsigned offset)
40{
41	return pinctrl_request_gpio(offset);
42}
43
44static void sh_gpio_free(struct gpio_chip *gc, unsigned offset)
45{
46	pinctrl_free_gpio(offset);
47}
48
49static void sh_gpio_set_value(struct sh_pfc *pfc, unsigned gpio, int value)
50{
51	struct pinmux_data_reg *dr = NULL;
52	int bit = 0;
53
54	if (sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
55		BUG();
56	else
57		sh_pfc_write_bit(dr, bit, value);
58}
59
60static int sh_gpio_get_value(struct sh_pfc *pfc, unsigned gpio)
61{
62	struct pinmux_data_reg *dr = NULL;
63	int bit = 0;
64
65	if (sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
66		return -EINVAL;
67
68	return sh_pfc_read_bit(dr, bit);
69}
70
71static int sh_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
72{
73	return pinctrl_gpio_direction_input(offset);
74}
75
76static int sh_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
77				    int value)
78{
79	sh_gpio_set_value(gpio_to_pfc(gc), offset, value);
80
81	return pinctrl_gpio_direction_output(offset);
82}
83
84static int sh_gpio_get(struct gpio_chip *gc, unsigned offset)
85{
86	return sh_gpio_get_value(gpio_to_pfc(gc), offset);
87}
88
89static void sh_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
90{
91	sh_gpio_set_value(gpio_to_pfc(gc), offset, value);
92}
93
94static int sh_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
95{
96	struct sh_pfc *pfc = gpio_to_pfc(gc);
97	pinmux_enum_t enum_id;
98	pinmux_enum_t *enum_ids;
99	int i, k, pos;
100
101	pos = 0;
102	enum_id = 0;
103	while (1) {
104		pos = sh_pfc_gpio_to_enum(pfc, offset, pos, &enum_id);
105		if (pos <= 0 || !enum_id)
106			break;
107
108		for (i = 0; i < pfc->info->gpio_irq_size; i++) {
109			enum_ids = pfc->info->gpio_irq[i].enum_ids;
110			for (k = 0; enum_ids[k]; k++) {
111				if (enum_ids[k] == enum_id)
112					return pfc->info->gpio_irq[i].irq;
113			}
114		}
115	}
116
117	return -ENOSYS;
118}
119
120static void sh_pfc_gpio_setup(struct sh_pfc_chip *chip)
121{
122	struct sh_pfc *pfc = chip->pfc;
123	struct gpio_chip *gc = &chip->gpio_chip;
124
125	gc->request = sh_gpio_request;
126	gc->free = sh_gpio_free;
127	gc->direction_input = sh_gpio_direction_input;
128	gc->get = sh_gpio_get;
129	gc->direction_output = sh_gpio_direction_output;
130	gc->set = sh_gpio_set;
131	gc->to_irq = sh_gpio_to_irq;
132
133	WARN_ON(pfc->info->first_gpio != 0); /* needs testing */
134
135	gc->label = pfc->info->name;
136	gc->owner = THIS_MODULE;
137	gc->base = pfc->info->first_gpio;
138	gc->ngpio = (pfc->info->last_gpio - pfc->info->first_gpio) + 1;
139}
140
141int sh_pfc_register_gpiochip(struct sh_pfc *pfc)
142{
143	struct sh_pfc_chip *chip;
144	int ret;
145
146	chip = devm_kzalloc(pfc->dev, sizeof(*chip), GFP_KERNEL);
147	if (unlikely(!chip))
148		return -ENOMEM;
149
150	chip->pfc = pfc;
151
152	sh_pfc_gpio_setup(chip);
153
154	ret = gpiochip_add(&chip->gpio_chip);
155	if (unlikely(ret < 0))
156		return ret;
157
158	pfc->gpio = chip;
159
160	pr_info("%s handling gpio %d -> %d\n",
161		pfc->info->name, pfc->info->first_gpio,
162		pfc->info->last_gpio);
163
164	return 0;
165}
166
167int sh_pfc_unregister_gpiochip(struct sh_pfc *pfc)
168{
169	struct sh_pfc_chip *chip = pfc->gpio;
170	int ret;
171
172	ret = gpiochip_remove(&chip->gpio_chip);
173	if (unlikely(ret < 0))
174		return ret;
175
176	pfc->gpio = NULL;
177	return 0;
178}
179