1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * arch/arm/common/bL_switcher_dummy_if.c -- b.L switcher dummy interface
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Created by: Nicolas Pitre, November 2012
6*4882a593Smuzhiyun * Copyright: (C) 2012-2013 Linaro Limited
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * Dummy interface to user space for debugging purpose only.
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #include <linux/init.h>
12*4882a593Smuzhiyun #include <linux/module.h>
13*4882a593Smuzhiyun #include <linux/fs.h>
14*4882a593Smuzhiyun #include <linux/miscdevice.h>
15*4882a593Smuzhiyun #include <linux/uaccess.h>
16*4882a593Smuzhiyun #include <asm/bL_switcher.h>
17*4882a593Smuzhiyun
bL_switcher_write(struct file * file,const char __user * buf,size_t len,loff_t * pos)18*4882a593Smuzhiyun static ssize_t bL_switcher_write(struct file *file, const char __user *buf,
19*4882a593Smuzhiyun size_t len, loff_t *pos)
20*4882a593Smuzhiyun {
21*4882a593Smuzhiyun unsigned char val[3];
22*4882a593Smuzhiyun unsigned int cpu, cluster;
23*4882a593Smuzhiyun int ret;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun pr_debug("%s\n", __func__);
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun if (len < 3)
28*4882a593Smuzhiyun return -EINVAL;
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun if (copy_from_user(val, buf, 3))
31*4882a593Smuzhiyun return -EFAULT;
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun /* format: <cpu#>,<cluster#> */
34*4882a593Smuzhiyun if (val[0] < '0' || val[0] > '9' ||
35*4882a593Smuzhiyun val[1] != ',' ||
36*4882a593Smuzhiyun val[2] < '0' || val[2] > '1')
37*4882a593Smuzhiyun return -EINVAL;
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun cpu = val[0] - '0';
40*4882a593Smuzhiyun cluster = val[2] - '0';
41*4882a593Smuzhiyun ret = bL_switch_request(cpu, cluster);
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun return ret ? : len;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun static const struct file_operations bL_switcher_fops = {
47*4882a593Smuzhiyun .write = bL_switcher_write,
48*4882a593Smuzhiyun .owner = THIS_MODULE,
49*4882a593Smuzhiyun };
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun static struct miscdevice bL_switcher_device = {
52*4882a593Smuzhiyun MISC_DYNAMIC_MINOR,
53*4882a593Smuzhiyun "b.L_switcher",
54*4882a593Smuzhiyun &bL_switcher_fops
55*4882a593Smuzhiyun };
56*4882a593Smuzhiyun module_misc_device(bL_switcher_device);
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun MODULE_AUTHOR("Nicolas Pitre <nico@linaro.org>");
59*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
60*4882a593Smuzhiyun MODULE_DESCRIPTION("big.LITTLE switcher dummy user interface");
61