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Commit | Line | Data |
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1e5db006 | 1 | /* |
c103de24 | 2 | * MC33880 high-side/low-side switch GPIO driver |
1e5db006 RR |
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> | |
5a0e3ad6 | 28 | #include <linux/slab.h> |
bb207ef1 | 29 | #include <linux/module.h> |
1e5db006 RR |
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 | */ | |
48 | struct mc33880 { | |
25985edc | 49 | struct mutex lock; /* protect from simultaneous accesses */ |
1e5db006 RR |
50 | u8 port_config; |
51 | struct gpio_chip chip; | |
52 | struct spi_device *spi; | |
53 | }; | |
54 | ||
55 | static int mc33880_write_config(struct mc33880 *mc) | |
56 | { | |
57 | return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config)); | |
58 | } | |
59 | ||
60 | ||
61 | static 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 | ||
72 | static 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 | ||
3836309d | 83 | static int mc33880_probe(struct spi_device *spi) |
1e5db006 RR |
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 | ||
632d8e55 | 104 | mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL); |
1e5db006 RR |
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) { | |
30db2bd1 JH |
133 | dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n", |
134 | ret); | |
1e5db006 RR |
135 | goto exit_destroy; |
136 | } | |
137 | ||
138 | ret = gpiochip_add(&mc->chip); | |
139 | if (ret) | |
140 | goto exit_destroy; | |
141 | ||
142 | return ret; | |
143 | ||
144 | exit_destroy: | |
145 | dev_set_drvdata(&spi->dev, NULL); | |
146 | mutex_destroy(&mc->lock); | |
1e5db006 RR |
147 | return ret; |
148 | } | |
149 | ||
206210ce | 150 | static int mc33880_remove(struct spi_device *spi) |
1e5db006 RR |
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); | |
632d8e55 | 162 | if (!ret) |
1e5db006 | 163 | mutex_destroy(&mc->lock); |
632d8e55 | 164 | else |
1e5db006 RR |
165 | dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n", |
166 | ret); | |
167 | ||
168 | return ret; | |
169 | } | |
170 | ||
171 | static struct spi_driver mc33880_driver = { | |
172 | .driver = { | |
173 | .name = DRIVER_NAME, | |
174 | .owner = THIS_MODULE, | |
175 | }, | |
176 | .probe = mc33880_probe, | |
8283c4ff | 177 | .remove = mc33880_remove, |
1e5db006 RR |
178 | }; |
179 | ||
180 | static int __init mc33880_init(void) | |
181 | { | |
182 | return spi_register_driver(&mc33880_driver); | |
183 | } | |
184 | /* register after spi postcore initcall and before | |
185 | * subsys initcalls that may rely on these GPIOs | |
186 | */ | |
187 | subsys_initcall(mc33880_init); | |
188 | ||
189 | static void __exit mc33880_exit(void) | |
190 | { | |
191 | spi_unregister_driver(&mc33880_driver); | |
192 | } | |
193 | module_exit(mc33880_exit); | |
194 | ||
195 | MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>"); | |
196 | MODULE_LICENSE("GPL v2"); | |
197 |