Commit | Line | Data |
---|---|---|
82c29810 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1e5db006 | 2 | /* |
c103de24 | 3 | * MC33880 high-side/low-side switch GPIO driver |
1e5db006 | 4 | * Copyright (c) 2009 Intel Corporation |
1e5db006 RR |
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> | |
03a3f19c | 15 | #include <linux/gpio/driver.h> |
5a0e3ad6 | 16 | #include <linux/slab.h> |
bb207ef1 | 17 | #include <linux/module.h> |
1e5db006 RR |
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 | */ | |
36 | struct mc33880 { | |
25985edc | 37 | struct mutex lock; /* protect from simultaneous accesses */ |
1e5db006 RR |
38 | u8 port_config; |
39 | struct gpio_chip chip; | |
40 | struct spi_device *spi; | |
41 | }; | |
42 | ||
43 | static int mc33880_write_config(struct mc33880 *mc) | |
44 | { | |
45 | return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config)); | |
46 | } | |
47 | ||
48 | ||
49 | static 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 | ||
60 | static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value) | |
61 | { | |
609f9692 | 62 | struct mc33880 *mc = gpiochip_get_data(chip); |
1e5db006 RR |
63 | |
64 | mutex_lock(&mc->lock); | |
65 | ||
66 | __mc33880_set(mc, offset, value); | |
67 | ||
68 | mutex_unlock(&mc->lock); | |
69 | } | |
70 | ||
3836309d | 71 | static int mc33880_probe(struct spi_device *spi) |
1e5db006 RR |
72 | { |
73 | struct mc33880 *mc; | |
74 | struct mc33880_platform_data *pdata; | |
75 | int ret; | |
76 | ||
e56aee18 | 77 | pdata = dev_get_platdata(&spi->dev); |
1e5db006 RR |
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 | ||
632d8e55 | 92 | mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL); |
1e5db006 RR |
93 | if (!mc) |
94 | return -ENOMEM; | |
95 | ||
96 | mutex_init(&mc->lock); | |
97 | ||
493294d4 | 98 | spi_set_drvdata(spi, mc); |
1e5db006 RR |
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; | |
9fb1f39e | 106 | mc->chip.can_sleep = true; |
58383c78 | 107 | mc->chip.parent = &spi->dev; |
1e5db006 RR |
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) { | |
30db2bd1 JH |
121 | dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n", |
122 | ret); | |
1e5db006 RR |
123 | goto exit_destroy; |
124 | } | |
125 | ||
609f9692 | 126 | ret = gpiochip_add_data(&mc->chip, mc); |
1e5db006 RR |
127 | if (ret) |
128 | goto exit_destroy; | |
129 | ||
130 | return ret; | |
131 | ||
132 | exit_destroy: | |
1e5db006 | 133 | mutex_destroy(&mc->lock); |
1e5db006 RR |
134 | return ret; |
135 | } | |
136 | ||
a0386bba | 137 | static void mc33880_remove(struct spi_device *spi) |
1e5db006 RR |
138 | { |
139 | struct mc33880 *mc; | |
1e5db006 | 140 | |
493294d4 | 141 | mc = spi_get_drvdata(spi); |
1e5db006 | 142 | |
9f5132ae | 143 | gpiochip_remove(&mc->chip); |
144 | mutex_destroy(&mc->lock); | |
1e5db006 RR |
145 | } |
146 | ||
147 | static struct spi_driver mc33880_driver = { | |
148 | .driver = { | |
149 | .name = DRIVER_NAME, | |
1e5db006 RR |
150 | }, |
151 | .probe = mc33880_probe, | |
8283c4ff | 152 | .remove = mc33880_remove, |
1e5db006 RR |
153 | }; |
154 | ||
155 | static 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 | */ | |
162 | subsys_initcall(mc33880_init); | |
163 | ||
164 | static void __exit mc33880_exit(void) | |
165 | { | |
166 | spi_unregister_driver(&mc33880_driver); | |
167 | } | |
168 | module_exit(mc33880_exit); | |
169 | ||
170 | MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>"); | |
171 | MODULE_LICENSE("GPL v2"); | |
172 |