xref: /openbmc/linux/drivers/mfd/ab8500-sysctrl.c (revision 0d456bad)
1 /*
2  * Copyright (C) ST-Ericsson SA 2010
3  * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
4  * License terms: GNU General Public License (GPL) version 2
5  */
6 
7 #include <linux/err.h>
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/mfd/abx500.h>
11 #include <linux/mfd/abx500/ab8500.h>
12 #include <linux/mfd/abx500/ab8500-sysctrl.h>
13 
14 static struct device *sysctrl_dev;
15 
16 static inline bool valid_bank(u8 bank)
17 {
18 	return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
19 		(bank == AB8500_SYS_CTRL2_BLOCK));
20 }
21 
22 int ab8500_sysctrl_read(u16 reg, u8 *value)
23 {
24 	u8 bank;
25 
26 	if (sysctrl_dev == NULL)
27 		return -EAGAIN;
28 
29 	bank = (reg >> 8);
30 	if (!valid_bank(bank))
31 		return -EINVAL;
32 
33 	return abx500_get_register_interruptible(sysctrl_dev, bank,
34 		(u8)(reg & 0xFF), value);
35 }
36 
37 int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
38 {
39 	u8 bank;
40 
41 	if (sysctrl_dev == NULL)
42 		return -EAGAIN;
43 
44 	bank = (reg >> 8);
45 	if (!valid_bank(bank))
46 		return -EINVAL;
47 
48 	return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
49 		(u8)(reg & 0xFF), mask, value);
50 }
51 
52 static int ab8500_sysctrl_probe(struct platform_device *pdev)
53 {
54 	sysctrl_dev = &pdev->dev;
55 	return 0;
56 }
57 
58 static int ab8500_sysctrl_remove(struct platform_device *pdev)
59 {
60 	sysctrl_dev = NULL;
61 	return 0;
62 }
63 
64 static struct platform_driver ab8500_sysctrl_driver = {
65 	.driver = {
66 		.name = "ab8500-sysctrl",
67 		.owner = THIS_MODULE,
68 	},
69 	.probe = ab8500_sysctrl_probe,
70 	.remove = ab8500_sysctrl_remove,
71 };
72 
73 static int __init ab8500_sysctrl_init(void)
74 {
75 	return platform_driver_register(&ab8500_sysctrl_driver);
76 }
77 subsys_initcall(ab8500_sysctrl_init);
78 
79 MODULE_AUTHOR("Mattias Nilsson <mattias.i.nilsson@stericsson.com");
80 MODULE_DESCRIPTION("AB8500 system control driver");
81 MODULE_LICENSE("GPL v2");
82