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1/*
2 * 74Hx164 - Generic serial-in/parallel-out 8-bits shift register GPIO driver
3 *
4 * Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
5 * Copyright (C) 2010 Miguel Gaio <miguel.gaio@efixo.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/init.h>
13#include <linux/mutex.h>
14#include <linux/spi/spi.h>
15#include <linux/spi/74x164.h>
16#include <linux/gpio.h>
17#include <linux/slab.h>
18
19struct gen_74x164_chip {
20 struct spi_device *spi;
21 struct gpio_chip gpio_chip;
22 struct mutex lock;
23 u8 port_config;
24};
25
26static struct gen_74x164_chip *gpio_to_74x164_chip(struct gpio_chip *gc)
27{
28 return container_of(gc, struct gen_74x164_chip, gpio_chip);
29}
30
31static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
32{
33 return spi_write(chip->spi,
34 &chip->port_config, sizeof(chip->port_config));
35}
36
37static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)
38{
39 struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
40 int ret;
41
42 mutex_lock(&chip->lock);
43 ret = (chip->port_config >> offset) & 0x1;
44 mutex_unlock(&chip->lock);
45
46 return ret;
47}
48
49static void gen_74x164_set_value(struct gpio_chip *gc,
50 unsigned offset, int val)
51{
52 struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
53
54 mutex_lock(&chip->lock);
55 if (val)
56 chip->port_config |= (1 << offset);
57 else
58 chip->port_config &= ~(1 << offset);
59
60 __gen_74x164_write_config(chip);
61 mutex_unlock(&chip->lock);
62}
63
64static int gen_74x164_direction_output(struct gpio_chip *gc,
65 unsigned offset, int val)
66{
67 gen_74x164_set_value(gc, offset, val);
68 return 0;
69}
70
71static int __devinit gen_74x164_probe(struct spi_device *spi)
72{
73 struct gen_74x164_chip *chip;
74 struct gen_74x164_chip_platform_data *pdata;
75 int ret;
76
77 pdata = spi->dev.platform_data;
78 if (!pdata || !pdata->base) {
79 dev_dbg(&spi->dev, "incorrect or missing platform data\n");
80 return -EINVAL;
81 }
82
83 /*
84 * bits_per_word cannot be configured in platform data
85 */
86 spi->bits_per_word = 8;
87
88 ret = spi_setup(spi);
89 if (ret < 0)
90 return ret;
91
92 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
93 if (!chip)
94 return -ENOMEM;
95
96 mutex_init(&chip->lock);
97
98 dev_set_drvdata(&spi->dev, chip);
99
100 chip->spi = spi;
101
102 chip->gpio_chip.label = spi->modalias;
103 chip->gpio_chip.direction_output = gen_74x164_direction_output;
104 chip->gpio_chip.get = gen_74x164_get_value;
105 chip->gpio_chip.set = gen_74x164_set_value;
106 chip->gpio_chip.base = pdata->base;
107 chip->gpio_chip.ngpio = 8;
108 chip->gpio_chip.can_sleep = 1;
109 chip->gpio_chip.dev = &spi->dev;
110 chip->gpio_chip.owner = THIS_MODULE;
111
112 ret = __gen_74x164_write_config(chip);
113 if (ret) {
114 dev_err(&spi->dev, "Failed writing: %d\n", ret);
115 goto exit_destroy;
116 }
117
118 ret = gpiochip_add(&chip->gpio_chip);
119 if (ret)
120 goto exit_destroy;
121
122 return ret;
123
124exit_destroy:
125 dev_set_drvdata(&spi->dev, NULL);
126 mutex_destroy(&chip->lock);
127 kfree(chip);
128 return ret;
129}
130
131static int __devexit gen_74x164_remove(struct spi_device *spi)
132{
133 struct gen_74x164_chip *chip;
134 int ret;
135
136 chip = dev_get_drvdata(&spi->dev);
137 if (chip == NULL)
138 return -ENODEV;
139
140 dev_set_drvdata(&spi->dev, NULL);
141
142 ret = gpiochip_remove(&chip->gpio_chip);
143 if (!ret) {
144 mutex_destroy(&chip->lock);
145 kfree(chip);
146 } else
147 dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
148 ret);
149
150 return ret;
151}
152
153static struct spi_driver gen_74x164_driver = {
154 .driver = {
155 .name = "74x164",
156 .owner = THIS_MODULE,
157 },
158 .probe = gen_74x164_probe,
159 .remove = __devexit_p(gen_74x164_remove),
160};
161
162static int __init gen_74x164_init(void)
163{
164 return spi_register_driver(&gen_74x164_driver);
165}
166subsys_initcall(gen_74x164_init);
167
168static void __exit gen_74x164_exit(void)
169{
170 spi_unregister_driver(&gen_74x164_driver);
171}
172module_exit(gen_74x164_exit);
173
174MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
175MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
176MODULE_DESCRIPTION("GPIO expander driver for 74X164 8-bits shift register");
177MODULE_LICENSE("GPL v2");
1/*
2 * 74Hx164 - Generic serial-in/parallel-out 8-bits shift register GPIO driver
3 *
4 * Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
5 * Copyright (C) 2010 Miguel Gaio <miguel.gaio@efixo.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/init.h>
13#include <linux/mutex.h>
14#include <linux/spi/spi.h>
15#include <linux/spi/74x164.h>
16#include <linux/gpio.h>
17#include <linux/slab.h>
18#include <linux/module.h>
19
20struct gen_74x164_chip {
21 struct spi_device *spi;
22 struct gpio_chip gpio_chip;
23 struct mutex lock;
24 u8 port_config;
25};
26
27static struct gen_74x164_chip *gpio_to_74x164_chip(struct gpio_chip *gc)
28{
29 return container_of(gc, struct gen_74x164_chip, gpio_chip);
30}
31
32static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
33{
34 return spi_write(chip->spi,
35 &chip->port_config, sizeof(chip->port_config));
36}
37
38static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)
39{
40 struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
41 int ret;
42
43 mutex_lock(&chip->lock);
44 ret = (chip->port_config >> offset) & 0x1;
45 mutex_unlock(&chip->lock);
46
47 return ret;
48}
49
50static void gen_74x164_set_value(struct gpio_chip *gc,
51 unsigned offset, int val)
52{
53 struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
54
55 mutex_lock(&chip->lock);
56 if (val)
57 chip->port_config |= (1 << offset);
58 else
59 chip->port_config &= ~(1 << offset);
60
61 __gen_74x164_write_config(chip);
62 mutex_unlock(&chip->lock);
63}
64
65static int gen_74x164_direction_output(struct gpio_chip *gc,
66 unsigned offset, int val)
67{
68 gen_74x164_set_value(gc, offset, val);
69 return 0;
70}
71
72static int __devinit gen_74x164_probe(struct spi_device *spi)
73{
74 struct gen_74x164_chip *chip;
75 struct gen_74x164_chip_platform_data *pdata;
76 int ret;
77
78 pdata = spi->dev.platform_data;
79 if (!pdata || !pdata->base) {
80 dev_dbg(&spi->dev, "incorrect or missing platform data\n");
81 return -EINVAL;
82 }
83
84 /*
85 * bits_per_word cannot be configured in platform data
86 */
87 spi->bits_per_word = 8;
88
89 ret = spi_setup(spi);
90 if (ret < 0)
91 return ret;
92
93 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
94 if (!chip)
95 return -ENOMEM;
96
97 mutex_init(&chip->lock);
98
99 dev_set_drvdata(&spi->dev, chip);
100
101 chip->spi = spi;
102
103 chip->gpio_chip.label = spi->modalias;
104 chip->gpio_chip.direction_output = gen_74x164_direction_output;
105 chip->gpio_chip.get = gen_74x164_get_value;
106 chip->gpio_chip.set = gen_74x164_set_value;
107 chip->gpio_chip.base = pdata->base;
108 chip->gpio_chip.ngpio = 8;
109 chip->gpio_chip.can_sleep = 1;
110 chip->gpio_chip.dev = &spi->dev;
111 chip->gpio_chip.owner = THIS_MODULE;
112
113 ret = __gen_74x164_write_config(chip);
114 if (ret) {
115 dev_err(&spi->dev, "Failed writing: %d\n", ret);
116 goto exit_destroy;
117 }
118
119 ret = gpiochip_add(&chip->gpio_chip);
120 if (ret)
121 goto exit_destroy;
122
123 return ret;
124
125exit_destroy:
126 dev_set_drvdata(&spi->dev, NULL);
127 mutex_destroy(&chip->lock);
128 kfree(chip);
129 return ret;
130}
131
132static int __devexit gen_74x164_remove(struct spi_device *spi)
133{
134 struct gen_74x164_chip *chip;
135 int ret;
136
137 chip = dev_get_drvdata(&spi->dev);
138 if (chip == NULL)
139 return -ENODEV;
140
141 dev_set_drvdata(&spi->dev, NULL);
142
143 ret = gpiochip_remove(&chip->gpio_chip);
144 if (!ret) {
145 mutex_destroy(&chip->lock);
146 kfree(chip);
147 } else
148 dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
149 ret);
150
151 return ret;
152}
153
154static struct spi_driver gen_74x164_driver = {
155 .driver = {
156 .name = "74x164",
157 .owner = THIS_MODULE,
158 },
159 .probe = gen_74x164_probe,
160 .remove = __devexit_p(gen_74x164_remove),
161};
162
163static int __init gen_74x164_init(void)
164{
165 return spi_register_driver(&gen_74x164_driver);
166}
167subsys_initcall(gen_74x164_init);
168
169static void __exit gen_74x164_exit(void)
170{
171 spi_unregister_driver(&gen_74x164_driver);
172}
173module_exit(gen_74x164_exit);
174
175MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
176MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
177MODULE_DESCRIPTION("GPIO expander driver for 74X164 8-bits shift register");
178MODULE_LICENSE("GPL v2");