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 | ||
8 | #include <linux/config.h> | |
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> |
1da177e4 LT |
16 | #include <asm/uaccess.h> |
17 | #include <asm/io.h> | |
18 | ||
7d7f2126 JC |
19 | #include <linux/types.h> |
20 | #include <linux/cdev.h> | |
21 | ||
1da177e4 LT |
22 | #include <linux/scx200_gpio.h> |
23 | ||
24 | #define NAME "scx200_gpio" | |
979b5ec3 JC |
25 | #define DEVNAME NAME |
26 | ||
27 | static struct platform_device *pdev; | |
1da177e4 LT |
28 | |
29 | MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); | |
30 | MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver"); | |
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 | ||
7d7f2126 JC |
37 | extern void scx200_gpio_dump(unsigned index); |
38 | ||
62c83cde | 39 | static ssize_t scx200_gpio_write(struct file *file, const char __user *data, |
1da177e4 LT |
40 | size_t len, loff_t *ppos) |
41 | { | |
42 | unsigned m = iminor(file->f_dentry->d_inode); | |
43 | size_t i; | |
9550a339 | 44 | int err = 0; |
1da177e4 LT |
45 | |
46 | for (i = 0; i < len; ++i) { | |
47 | char c; | |
62c83cde | 48 | if (get_user(c, data + i)) |
1da177e4 | 49 | return -EFAULT; |
62c83cde JC |
50 | switch (c) { |
51 | case '0': | |
52 | scx200_gpio_set(m, 0); | |
1da177e4 | 53 | break; |
62c83cde JC |
54 | case '1': |
55 | scx200_gpio_set(m, 1); | |
1da177e4 LT |
56 | break; |
57 | case 'O': | |
58 | printk(KERN_INFO NAME ": GPIO%d output enabled\n", m); | |
59 | scx200_gpio_configure(m, ~1, 1); | |
60 | break; | |
61 | case 'o': | |
62 | printk(KERN_INFO NAME ": GPIO%d output disabled\n", m); | |
63 | scx200_gpio_configure(m, ~1, 0); | |
64 | break; | |
65 | case 'T': | |
66 | printk(KERN_INFO NAME ": GPIO%d output is push pull\n", m); | |
67 | scx200_gpio_configure(m, ~2, 2); | |
68 | break; | |
69 | case 't': | |
70 | printk(KERN_INFO NAME ": GPIO%d output is open drain\n", m); | |
71 | scx200_gpio_configure(m, ~2, 0); | |
72 | break; | |
73 | case 'P': | |
74 | printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m); | |
75 | scx200_gpio_configure(m, ~4, 4); | |
76 | break; | |
77 | case 'p': | |
78 | printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m); | |
79 | scx200_gpio_configure(m, ~4, 0); | |
80 | break; | |
9550a339 JC |
81 | |
82 | case 'v': | |
83 | /* View Current pin settings */ | |
84 | scx200_gpio_dump(m); | |
85 | break; | |
86 | case '\n': | |
87 | /* end of settings string, do nothing */ | |
88 | break; | |
89 | default: | |
90 | printk(KERN_ERR NAME | |
91 | ": GPIO-%2d bad setting: chr<0x%2x>\n", m, | |
92 | (int)c); | |
93 | err++; | |
1da177e4 LT |
94 | } |
95 | } | |
9550a339 JC |
96 | if (err) |
97 | return -EINVAL; /* full string handled, report error */ | |
1da177e4 LT |
98 | |
99 | return len; | |
100 | } | |
101 | ||
102 | static ssize_t scx200_gpio_read(struct file *file, char __user *buf, | |
103 | size_t len, loff_t *ppos) | |
104 | { | |
105 | unsigned m = iminor(file->f_dentry->d_inode); | |
106 | int value; | |
107 | ||
108 | value = scx200_gpio_get(m); | |
109 | if (put_user(value ? '1' : '0', buf)) | |
110 | return -EFAULT; | |
62c83cde | 111 | |
1da177e4 LT |
112 | return 1; |
113 | } | |
114 | ||
115 | static int scx200_gpio_open(struct inode *inode, struct file *file) | |
116 | { | |
117 | unsigned m = iminor(inode); | |
118 | if (m > 63) | |
119 | return -EINVAL; | |
120 | return nonseekable_open(inode, file); | |
121 | } | |
122 | ||
123 | static int scx200_gpio_release(struct inode *inode, struct file *file) | |
124 | { | |
125 | return 0; | |
126 | } | |
127 | ||
128 | ||
129 | static struct file_operations scx200_gpio_fops = { | |
130 | .owner = THIS_MODULE, | |
131 | .write = scx200_gpio_write, | |
132 | .read = scx200_gpio_read, | |
133 | .open = scx200_gpio_open, | |
134 | .release = scx200_gpio_release, | |
135 | }; | |
136 | ||
7d7f2126 | 137 | struct cdev *scx200_devices; |
979b5ec3 | 138 | static int num_pins = 32; |
7d7f2126 | 139 | |
1da177e4 LT |
140 | static int __init scx200_gpio_init(void) |
141 | { | |
7d7f2126 JC |
142 | int rc, i; |
143 | dev_t dev = MKDEV(major, 0); | |
1da177e4 | 144 | |
1da177e4 | 145 | if (!scx200_gpio_present()) { |
7d7f2126 | 146 | printk(KERN_ERR NAME ": no SCx200 gpio present\n"); |
1da177e4 LT |
147 | return -ENODEV; |
148 | } | |
979b5ec3 JC |
149 | |
150 | /* support dev_dbg() with pdev->dev */ | |
151 | pdev = platform_device_alloc(DEVNAME, 0); | |
152 | if (!pdev) | |
153 | return -ENOMEM; | |
154 | ||
155 | rc = platform_device_add(pdev); | |
156 | if (rc) | |
157 | goto undo_malloc; | |
158 | ||
7d7f2126 | 159 | if (major) |
979b5ec3 | 160 | rc = register_chrdev_region(dev, num_pins, "scx200_gpio"); |
7d7f2126 | 161 | else { |
979b5ec3 | 162 | rc = alloc_chrdev_region(&dev, 0, num_pins, "scx200_gpio"); |
7d7f2126 | 163 | major = MAJOR(dev); |
1da177e4 | 164 | } |
7d7f2126 | 165 | if (rc < 0) { |
979b5ec3 JC |
166 | dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc); |
167 | goto undo_platform_device_add; | |
7d7f2126 | 168 | } |
979b5ec3 | 169 | scx200_devices = kzalloc(num_pins * sizeof(struct cdev), GFP_KERNEL); |
7d7f2126 JC |
170 | if (!scx200_devices) { |
171 | rc = -ENOMEM; | |
979b5ec3 | 172 | goto undo_chrdev_region; |
7d7f2126 | 173 | } |
979b5ec3 | 174 | for (i = 0; i < num_pins; i++) { |
7d7f2126 JC |
175 | struct cdev *cdev = &scx200_devices[i]; |
176 | cdev_init(cdev, &scx200_gpio_fops); | |
177 | cdev->owner = THIS_MODULE; | |
7d7f2126 | 178 | rc = cdev_add(cdev, MKDEV(major, i), 1); |
979b5ec3 | 179 | /* tolerate 'minor' errors */ |
7d7f2126 | 180 | if (rc) |
979b5ec3 | 181 | dev_err(&pdev->dev, "Error %d on minor %d", rc, i); |
1da177e4 LT |
182 | } |
183 | ||
979b5ec3 | 184 | return 0; /* succeed */ |
7d7f2126 | 185 | |
979b5ec3 JC |
186 | undo_chrdev_region: |
187 | unregister_chrdev_region(dev, num_pins); | |
188 | undo_platform_device_add: | |
189 | platform_device_put(pdev); | |
190 | undo_malloc: | |
191 | kfree(pdev); | |
7d7f2126 | 192 | return rc; |
1da177e4 LT |
193 | } |
194 | ||
195 | static void __exit scx200_gpio_cleanup(void) | |
196 | { | |
7d7f2126 | 197 | kfree(scx200_devices); |
979b5ec3 JC |
198 | unregister_chrdev_region(MKDEV(major, 0), num_pins); |
199 | platform_device_put(pdev); | |
200 | platform_device_unregister(pdev); | |
201 | /* kfree(pdev); */ | |
1da177e4 LT |
202 | } |
203 | ||
204 | module_init(scx200_gpio_init); | |
205 | module_exit(scx200_gpio_cleanup); |