Loading...
1/*
2 * MC33880 high-side/low-side switch GPIO driver
3 * Copyright (c) 2009 Intel Corporation
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19/* Supports:
20 * Freescale MC33880 high-side/low-side switch
21 */
22
23#include <linux/init.h>
24#include <linux/mutex.h>
25#include <linux/spi/spi.h>
26#include <linux/spi/mc33880.h>
27#include <linux/gpio.h>
28#include <linux/slab.h>
29#include <linux/module.h>
30
31#define DRIVER_NAME "mc33880"
32
33/*
34 * Pin configurations, see MAX7301 datasheet page 6
35 */
36#define PIN_CONFIG_MASK 0x03
37#define PIN_CONFIG_IN_PULLUP 0x03
38#define PIN_CONFIG_IN_WO_PULLUP 0x02
39#define PIN_CONFIG_OUT 0x01
40
41#define PIN_NUMBER 8
42
43
44/*
45 * Some registers must be read back to modify.
46 * To save time we cache them here in memory
47 */
48struct mc33880 {
49 struct mutex lock; /* protect from simultaneous accesses */
50 u8 port_config;
51 struct gpio_chip chip;
52 struct spi_device *spi;
53};
54
55static int mc33880_write_config(struct mc33880 *mc)
56{
57 return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
58}
59
60
61static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
62{
63 if (value)
64 mc->port_config |= 1 << offset;
65 else
66 mc->port_config &= ~(1 << offset);
67
68 return mc33880_write_config(mc);
69}
70
71
72static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
73{
74 struct mc33880 *mc = container_of(chip, struct mc33880, chip);
75
76 mutex_lock(&mc->lock);
77
78 __mc33880_set(mc, offset, value);
79
80 mutex_unlock(&mc->lock);
81}
82
83static int __devinit mc33880_probe(struct spi_device *spi)
84{
85 struct mc33880 *mc;
86 struct mc33880_platform_data *pdata;
87 int ret;
88
89 pdata = spi->dev.platform_data;
90 if (!pdata || !pdata->base) {
91 dev_dbg(&spi->dev, "incorrect or missing platform data\n");
92 return -EINVAL;
93 }
94
95 /*
96 * bits_per_word cannot be configured in platform data
97 */
98 spi->bits_per_word = 8;
99
100 ret = spi_setup(spi);
101 if (ret < 0)
102 return ret;
103
104 mc = kzalloc(sizeof(struct mc33880), GFP_KERNEL);
105 if (!mc)
106 return -ENOMEM;
107
108 mutex_init(&mc->lock);
109
110 dev_set_drvdata(&spi->dev, mc);
111
112 mc->spi = spi;
113
114 mc->chip.label = DRIVER_NAME,
115 mc->chip.set = mc33880_set;
116 mc->chip.base = pdata->base;
117 mc->chip.ngpio = PIN_NUMBER;
118 mc->chip.can_sleep = 1;
119 mc->chip.dev = &spi->dev;
120 mc->chip.owner = THIS_MODULE;
121
122 mc->port_config = 0x00;
123 /* write twice, because during initialisation the first setting
124 * is just for testing SPI communication, and the second is the
125 * "real" configuration
126 */
127 ret = mc33880_write_config(mc);
128 mc->port_config = 0x00;
129 if (!ret)
130 ret = mc33880_write_config(mc);
131
132 if (ret) {
133 printk(KERN_ERR "Failed writing to " DRIVER_NAME ": %d\n", ret);
134 goto exit_destroy;
135 }
136
137 ret = gpiochip_add(&mc->chip);
138 if (ret)
139 goto exit_destroy;
140
141 return ret;
142
143exit_destroy:
144 dev_set_drvdata(&spi->dev, NULL);
145 mutex_destroy(&mc->lock);
146 kfree(mc);
147 return ret;
148}
149
150static int __devexit mc33880_remove(struct spi_device *spi)
151{
152 struct mc33880 *mc;
153 int ret;
154
155 mc = dev_get_drvdata(&spi->dev);
156 if (mc == NULL)
157 return -ENODEV;
158
159 dev_set_drvdata(&spi->dev, NULL);
160
161 ret = gpiochip_remove(&mc->chip);
162 if (!ret) {
163 mutex_destroy(&mc->lock);
164 kfree(mc);
165 } else
166 dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
167 ret);
168
169 return ret;
170}
171
172static struct spi_driver mc33880_driver = {
173 .driver = {
174 .name = DRIVER_NAME,
175 .owner = THIS_MODULE,
176 },
177 .probe = mc33880_probe,
178 .remove = __devexit_p(mc33880_remove),
179};
180
181static int __init mc33880_init(void)
182{
183 return spi_register_driver(&mc33880_driver);
184}
185/* register after spi postcore initcall and before
186 * subsys initcalls that may rely on these GPIOs
187 */
188subsys_initcall(mc33880_init);
189
190static void __exit mc33880_exit(void)
191{
192 spi_unregister_driver(&mc33880_driver);
193}
194module_exit(mc33880_exit);
195
196MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
197MODULE_LICENSE("GPL v2");
198
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * MC33880 high-side/low-side switch GPIO driver
4 * Copyright (c) 2009 Intel Corporation
5 */
6
7/* Supports:
8 * Freescale MC33880 high-side/low-side switch
9 */
10
11#include <linux/init.h>
12#include <linux/mutex.h>
13#include <linux/spi/spi.h>
14#include <linux/spi/mc33880.h>
15#include <linux/gpio/driver.h>
16#include <linux/slab.h>
17#include <linux/module.h>
18
19#define DRIVER_NAME "mc33880"
20
21/*
22 * Pin configurations, see MAX7301 datasheet page 6
23 */
24#define PIN_CONFIG_MASK 0x03
25#define PIN_CONFIG_IN_PULLUP 0x03
26#define PIN_CONFIG_IN_WO_PULLUP 0x02
27#define PIN_CONFIG_OUT 0x01
28
29#define PIN_NUMBER 8
30
31
32/*
33 * Some registers must be read back to modify.
34 * To save time we cache them here in memory
35 */
36struct mc33880 {
37 struct mutex lock; /* protect from simultaneous accesses */
38 u8 port_config;
39 struct gpio_chip chip;
40 struct spi_device *spi;
41};
42
43static int mc33880_write_config(struct mc33880 *mc)
44{
45 return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
46}
47
48
49static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
50{
51 if (value)
52 mc->port_config |= 1 << offset;
53 else
54 mc->port_config &= ~(1 << offset);
55
56 return mc33880_write_config(mc);
57}
58
59
60static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
61{
62 struct mc33880 *mc = gpiochip_get_data(chip);
63
64 mutex_lock(&mc->lock);
65
66 __mc33880_set(mc, offset, value);
67
68 mutex_unlock(&mc->lock);
69}
70
71static int mc33880_probe(struct spi_device *spi)
72{
73 struct mc33880 *mc;
74 struct mc33880_platform_data *pdata;
75 int ret;
76
77 pdata = dev_get_platdata(&spi->dev);
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 mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL);
93 if (!mc)
94 return -ENOMEM;
95
96 mutex_init(&mc->lock);
97
98 spi_set_drvdata(spi, mc);
99
100 mc->spi = spi;
101
102 mc->chip.label = DRIVER_NAME,
103 mc->chip.set = mc33880_set;
104 mc->chip.base = pdata->base;
105 mc->chip.ngpio = PIN_NUMBER;
106 mc->chip.can_sleep = true;
107 mc->chip.parent = &spi->dev;
108 mc->chip.owner = THIS_MODULE;
109
110 mc->port_config = 0x00;
111 /* write twice, because during initialisation the first setting
112 * is just for testing SPI communication, and the second is the
113 * "real" configuration
114 */
115 ret = mc33880_write_config(mc);
116 mc->port_config = 0x00;
117 if (!ret)
118 ret = mc33880_write_config(mc);
119
120 if (ret) {
121 dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n",
122 ret);
123 goto exit_destroy;
124 }
125
126 ret = gpiochip_add_data(&mc->chip, mc);
127 if (ret)
128 goto exit_destroy;
129
130 return ret;
131
132exit_destroy:
133 mutex_destroy(&mc->lock);
134 return ret;
135}
136
137static void mc33880_remove(struct spi_device *spi)
138{
139 struct mc33880 *mc;
140
141 mc = spi_get_drvdata(spi);
142
143 gpiochip_remove(&mc->chip);
144 mutex_destroy(&mc->lock);
145}
146
147static struct spi_driver mc33880_driver = {
148 .driver = {
149 .name = DRIVER_NAME,
150 },
151 .probe = mc33880_probe,
152 .remove = mc33880_remove,
153};
154
155static int __init mc33880_init(void)
156{
157 return spi_register_driver(&mc33880_driver);
158}
159/* register after spi postcore initcall and before
160 * subsys initcalls that may rely on these GPIOs
161 */
162subsys_initcall(mc33880_init);
163
164static void __exit mc33880_exit(void)
165{
166 spi_unregister_driver(&mc33880_driver);
167}
168module_exit(mc33880_exit);
169
170MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
171MODULE_LICENSE("GPL v2");
172