Commit | Line | Data |
---|---|---|
09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
62c83cde | 2 | /* linux/drivers/char/scx200_gpio.c |
1da177e4 LT |
3 | |
4 | National Semiconductor SCx200 GPIO driver. Allows a user space | |
5 | process to play with the GPIO pins. | |
6 | ||
7 | Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */ | |
8 | ||
979b5ec3 | 9 | #include <linux/device.h> |
1da177e4 LT |
10 | #include <linux/fs.h> |
11 | #include <linux/module.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/init.h> | |
979b5ec3 | 15 | #include <linux/platform_device.h> |
7c0f6ba6 | 16 | #include <linux/uaccess.h> |
1da177e4 LT |
17 | #include <asm/io.h> |
18 | ||
7d7f2126 JC |
19 | #include <linux/types.h> |
20 | #include <linux/cdev.h> | |
21 | ||
1da177e4 | 22 | #include <linux/scx200_gpio.h> |
fe3a168a | 23 | #include <linux/nsc_gpio.h> |
1da177e4 | 24 | |
ae2d1f2f | 25 | #define DRVNAME "scx200_gpio" |
979b5ec3 JC |
26 | |
27 | static struct platform_device *pdev; | |
1da177e4 LT |
28 | |
29 | MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); | |
ae2d1f2f | 30 | MODULE_DESCRIPTION("NatSemi/AMD SCx200 GPIO Pin Driver"); |
1da177e4 LT |
31 | MODULE_LICENSE("GPL"); |
32 | ||
33 | static int major = 0; /* default to dynamic major */ | |
34 | module_param(major, int, 0); | |
35 | MODULE_PARM_DESC(major, "Major device number"); | |
36 | ||
ae2d1f2f JC |
37 | #define MAX_PINS 32 /* 64 later, when known ok */ |
38 | ||
2e8f7a31 | 39 | struct nsc_gpio_ops scx200_gpio_ops = { |
fe3a168a JC |
40 | .owner = THIS_MODULE, |
41 | .gpio_config = scx200_gpio_configure, | |
0e41ef3c | 42 | .gpio_dump = nsc_gpio_dump, |
fe3a168a JC |
43 | .gpio_get = scx200_gpio_get, |
44 | .gpio_set = scx200_gpio_set, | |
fe3a168a JC |
45 | .gpio_change = scx200_gpio_change, |
46 | .gpio_current = scx200_gpio_current | |
47 | }; | |
58012cd7 | 48 | EXPORT_SYMBOL_GPL(scx200_gpio_ops); |
fe3a168a | 49 | |
1da177e4 LT |
50 | static int scx200_gpio_open(struct inode *inode, struct file *file) |
51 | { | |
52 | unsigned m = iminor(inode); | |
2e8f7a31 | 53 | file->private_data = &scx200_gpio_ops; |
c3dc8071 | 54 | |
ae2d1f2f | 55 | if (m >= MAX_PINS) |
1da177e4 LT |
56 | return -EINVAL; |
57 | return nonseekable_open(inode, file); | |
58 | } | |
59 | ||
60 | static int scx200_gpio_release(struct inode *inode, struct file *file) | |
61 | { | |
62 | return 0; | |
63 | } | |
64 | ||
2e8f7a31 | 65 | static const struct file_operations scx200_gpio_fileops = { |
1da177e4 | 66 | .owner = THIS_MODULE, |
1a66fdf0 JC |
67 | .write = nsc_gpio_write, |
68 | .read = nsc_gpio_read, | |
1da177e4 LT |
69 | .open = scx200_gpio_open, |
70 | .release = scx200_gpio_release, | |
6038f373 | 71 | .llseek = no_llseek, |
1da177e4 LT |
72 | }; |
73 | ||
c8ad9681 | 74 | static struct cdev scx200_gpio_cdev; /* use 1 cdev for all pins */ |
7d7f2126 | 75 | |
1da177e4 LT |
76 | static int __init scx200_gpio_init(void) |
77 | { | |
635adb6c | 78 | int rc; |
ae2d1f2f | 79 | dev_t devid; |
1da177e4 | 80 | |
1da177e4 | 81 | if (!scx200_gpio_present()) { |
ae2d1f2f | 82 | printk(KERN_ERR DRVNAME ": no SCx200 gpio present\n"); |
1da177e4 LT |
83 | return -ENODEV; |
84 | } | |
979b5ec3 JC |
85 | |
86 | /* support dev_dbg() with pdev->dev */ | |
ae2d1f2f | 87 | pdev = platform_device_alloc(DRVNAME, 0); |
979b5ec3 JC |
88 | if (!pdev) |
89 | return -ENOMEM; | |
90 | ||
91 | rc = platform_device_add(pdev); | |
92 | if (rc) | |
93 | goto undo_malloc; | |
94 | ||
f31000e5 | 95 | /* nsc_gpio uses dev_dbg(), so needs this */ |
2e8f7a31 | 96 | scx200_gpio_ops.dev = &pdev->dev; |
f31000e5 | 97 | |
ae2d1f2f JC |
98 | if (major) { |
99 | devid = MKDEV(major, 0); | |
100 | rc = register_chrdev_region(devid, MAX_PINS, "scx200_gpio"); | |
101 | } else { | |
102 | rc = alloc_chrdev_region(&devid, 0, MAX_PINS, "scx200_gpio"); | |
103 | major = MAJOR(devid); | |
1da177e4 | 104 | } |
7d7f2126 | 105 | if (rc < 0) { |
979b5ec3 JC |
106 | dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc); |
107 | goto undo_platform_device_add; | |
7d7f2126 | 108 | } |
635adb6c | 109 | |
2e8f7a31 | 110 | cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops); |
635adb6c | 111 | cdev_add(&scx200_gpio_cdev, devid, MAX_PINS); |
1da177e4 | 112 | |
979b5ec3 | 113 | return 0; /* succeed */ |
7d7f2126 | 114 | |
979b5ec3 | 115 | undo_platform_device_add: |
1017f6af | 116 | platform_device_del(pdev); |
979b5ec3 | 117 | undo_malloc: |
1017f6af IM |
118 | platform_device_put(pdev); |
119 | ||
7d7f2126 | 120 | return rc; |
1da177e4 LT |
121 | } |
122 | ||
123 | static void __exit scx200_gpio_cleanup(void) | |
124 | { | |
635adb6c JC |
125 | cdev_del(&scx200_gpio_cdev); |
126 | /* cdev_put(&scx200_gpio_cdev); */ | |
127 | ||
ae2d1f2f | 128 | unregister_chrdev_region(MKDEV(major, 0), MAX_PINS); |
979b5ec3 | 129 | platform_device_unregister(pdev); |
1da177e4 LT |
130 | } |
131 | ||
132 | module_init(scx200_gpio_init); | |
133 | module_exit(scx200_gpio_cleanup); |