gpio.c revision 6e54d8d252ed09ae148af6565971974af9a96e10 
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/sh_pfc.h>
20#include <linux/slab.h>
21#include <linux/spinlock.h>
22
23#include "core.h"
24
25struct sh_pfc_chip {
26	struct sh_pfc		*pfc;
27	struct gpio_chip	gpio_chip;
28};
29
30static struct sh_pfc_chip *gpio_to_pfc_chip(struct gpio_chip *gc)
31{
32	return container_of(gc, struct sh_pfc_chip, gpio_chip);
33}
34
35static struct sh_pfc *gpio_to_pfc(struct gpio_chip *gc)
36{
37	return gpio_to_pfc_chip(gc)->pfc;
38}
39
40static int sh_gpio_request(struct gpio_chip *gc, unsigned offset)
41{
42	return pinctrl_request_gpio(offset);
43}
44
45static void sh_gpio_free(struct gpio_chip *gc, unsigned offset)
46{
47	pinctrl_free_gpio(offset);
48}
49
50static void sh_gpio_set_value(struct sh_pfc *pfc, unsigned gpio, int value)
51{
52	struct pinmux_data_reg *dr = NULL;
53	int bit = 0;
54
55	if (sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
56		BUG();
57	else
58		sh_pfc_write_bit(dr, bit, value);
59}
60
61static int sh_gpio_get_value(struct sh_pfc *pfc, unsigned gpio)
62{
63	struct pinmux_data_reg *dr = NULL;
64	int bit = 0;
65
66	if (sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
67		return -EINVAL;
68
69	return sh_pfc_read_bit(dr, bit);
70}
71
72static int sh_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
73{
74	return pinctrl_gpio_direction_input(offset);
75}
76
77static int sh_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
78				    int value)
79{
80	sh_gpio_set_value(gpio_to_pfc(gc), offset, value);
81
82	return pinctrl_gpio_direction_output(offset);
83}
84
85static int sh_gpio_get(struct gpio_chip *gc, unsigned offset)
86{
87	return sh_gpio_get_value(gpio_to_pfc(gc), offset);
88}
89
90static void sh_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
91{
92	sh_gpio_set_value(gpio_to_pfc(gc), offset, value);
93}
94
95static int sh_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
96{
97	struct sh_pfc *pfc = gpio_to_pfc(gc);
98	pinmux_enum_t enum_id;
99	pinmux_enum_t *enum_ids;
100	int i, k, pos;
101
102	pos = 0;
103	enum_id = 0;
104	while (1) {
105		pos = sh_pfc_gpio_to_enum(pfc, offset, pos, &enum_id);
106		if (pos <= 0 || !enum_id)
107			break;
108
109		for (i = 0; i < pfc->pdata->gpio_irq_size; i++) {
110			enum_ids = pfc->pdata->gpio_irq[i].enum_ids;
111			for (k = 0; enum_ids[k]; k++) {
112				if (enum_ids[k] == enum_id)
113					return pfc->pdata->gpio_irq[i].irq;
114			}
115		}
116	}
117
118	return -ENOSYS;
119}
120
121static void sh_pfc_gpio_setup(struct sh_pfc_chip *chip)
122{
123	struct sh_pfc *pfc = chip->pfc;
124	struct gpio_chip *gc = &chip->gpio_chip;
125
126	gc->request = sh_gpio_request;
127	gc->free = sh_gpio_free;
128	gc->direction_input = sh_gpio_direction_input;
129	gc->get = sh_gpio_get;
130	gc->direction_output = sh_gpio_direction_output;
131	gc->set = sh_gpio_set;
132	gc->to_irq = sh_gpio_to_irq;
133
134	WARN_ON(pfc->pdata->first_gpio != 0); /* needs testing */
135
136	gc->label = pfc->pdata->name;
137	gc->owner = THIS_MODULE;
138	gc->base = pfc->pdata->first_gpio;
139	gc->ngpio = (pfc->pdata->last_gpio - pfc->pdata->first_gpio) + 1;
140}
141
142int sh_pfc_register_gpiochip(struct sh_pfc *pfc)
143{
144	struct sh_pfc_chip *chip;
145	int ret;
146
147	chip = devm_kzalloc(pfc->dev, sizeof(*chip), GFP_KERNEL);
148	if (unlikely(!chip))
149		return -ENOMEM;
150
151	chip->pfc = pfc;
152
153	sh_pfc_gpio_setup(chip);
154
155	ret = gpiochip_add(&chip->gpio_chip);
156	if (unlikely(ret < 0))
157		return ret;
158
159	pfc->gpio = chip;
160
161	pr_info("%s handling gpio %d -> %d\n",
162		pfc->pdata->name, pfc->pdata->first_gpio,
163		pfc->pdata->last_gpio);
164
165	return 0;
166}
167
168int sh_pfc_unregister_gpiochip(struct sh_pfc *pfc)
169{
170	struct sh_pfc_chip *chip = pfc->gpio;
171	int ret;
172
173	ret = gpiochip_remove(&chip->gpio_chip);
174	if (unlikely(ret < 0))
175		return ret;
176
177	pfc->gpio = NULL;
178	return 0;
179}
180