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