1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * arch/arm/common/bL_switcher_dummy_if.c -- b.L switcher dummy interface |
4 | * |
5 | * Created by: Nicolas Pitre, November 2012 |
6 | * Copyright: (C) 2012-2013 Linaro Limited |
7 | * |
8 | * Dummy interface to user space for debugging purpose only. |
9 | */ |
10 | |
11 | #include <linux/init.h> |
12 | #include <linux/module.h> |
13 | #include <linux/fs.h> |
14 | #include <linux/miscdevice.h> |
15 | #include <linux/uaccess.h> |
16 | #include <asm/bL_switcher.h> |
17 | |
18 | static ssize_t bL_switcher_write(struct file *file, const char __user *buf, |
19 | size_t len, loff_t *pos) |
20 | { |
21 | unsigned char val[3]; |
22 | unsigned int cpu, cluster; |
23 | int ret; |
24 | |
25 | pr_debug("%s\n" , __func__); |
26 | |
27 | if (len < 3) |
28 | return -EINVAL; |
29 | |
30 | if (copy_from_user(to: val, from: buf, n: 3)) |
31 | return -EFAULT; |
32 | |
33 | /* format: <cpu#>,<cluster#> */ |
34 | if (val[0] < '0' || val[0] > '9' || |
35 | val[1] != ',' || |
36 | val[2] < '0' || val[2] > '1') |
37 | return -EINVAL; |
38 | |
39 | cpu = val[0] - '0'; |
40 | cluster = val[2] - '0'; |
41 | ret = bL_switch_request(cpu, cluster); |
42 | |
43 | return ret ? : len; |
44 | } |
45 | |
46 | static const struct file_operations bL_switcher_fops = { |
47 | .write = bL_switcher_write, |
48 | .owner = THIS_MODULE, |
49 | }; |
50 | |
51 | static struct miscdevice bL_switcher_device = { |
52 | MISC_DYNAMIC_MINOR, |
53 | "b.L_switcher" , |
54 | &bL_switcher_fops |
55 | }; |
56 | module_misc_device(bL_switcher_device); |
57 | |
58 | MODULE_AUTHOR("Nicolas Pitre <nico@linaro.org>" ); |
59 | MODULE_LICENSE("GPL v2" ); |
60 | MODULE_DESCRIPTION("big.LITTLE switcher dummy user interface" ); |
61 | |