Commit | Line | Data |
---|---|---|
4a315e34 AB |
1 | /* |
2 | * Reset driver for Axxia devices | |
3 | * | |
4 | * Copyright (C) 2014 LSI | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 and | |
8 | * only version 2 as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | */ | |
16 | #include <linux/init.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/mfd/syscon.h> | |
21 | #include <linux/module.h> | |
fcf01c51 | 22 | #include <linux/notifier.h> |
4a315e34 AB |
23 | #include <linux/of.h> |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/reboot.h> | |
26 | #include <linux/regmap.h> | |
27 | ||
4a315e34 AB |
28 | #define SC_CRIT_WRITE_KEY 0x1000 |
29 | #define SC_LATCH_ON_RESET 0x1004 | |
30 | #define SC_RESET_CONTROL 0x1008 | |
31 | #define RSTCTL_RST_ZERO (1<<3) | |
32 | #define RSTCTL_RST_FAB (1<<2) | |
33 | #define RSTCTL_RST_CHIP (1<<1) | |
34 | #define RSTCTL_RST_SYS (1<<0) | |
35 | #define SC_EFUSE_INT_STATUS 0x180c | |
36 | #define EFUSE_READ_DONE (1<<31) | |
37 | ||
38 | static struct regmap *syscon; | |
39 | ||
fcf01c51 GR |
40 | static int axxia_restart_handler(struct notifier_block *this, |
41 | unsigned long mode, void *cmd) | |
4a315e34 AB |
42 | { |
43 | /* Access Key (0xab) */ | |
44 | regmap_write(syscon, SC_CRIT_WRITE_KEY, 0xab); | |
45 | /* Select internal boot from 0xffff0000 */ | |
46 | regmap_write(syscon, SC_LATCH_ON_RESET, 0x00000040); | |
47 | /* Assert ResetReadDone (to avoid hanging in boot ROM) */ | |
48 | regmap_write(syscon, SC_EFUSE_INT_STATUS, EFUSE_READ_DONE); | |
49 | /* Assert chip reset */ | |
50 | regmap_update_bits(syscon, SC_RESET_CONTROL, | |
51 | RSTCTL_RST_CHIP, RSTCTL_RST_CHIP); | |
fcf01c51 GR |
52 | |
53 | return NOTIFY_DONE; | |
4a315e34 AB |
54 | } |
55 | ||
fcf01c51 GR |
56 | static struct notifier_block axxia_restart_nb = { |
57 | .notifier_call = axxia_restart_handler, | |
58 | .priority = 128, | |
59 | }; | |
60 | ||
4a315e34 AB |
61 | static int axxia_reset_probe(struct platform_device *pdev) |
62 | { | |
63 | struct device *dev = &pdev->dev; | |
fcf01c51 | 64 | int err; |
4a315e34 AB |
65 | |
66 | syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon"); | |
67 | if (IS_ERR(syscon)) { | |
68 | pr_err("%s: syscon lookup failed\n", dev->of_node->name); | |
69 | return PTR_ERR(syscon); | |
70 | } | |
71 | ||
fcf01c51 GR |
72 | err = register_restart_handler(&axxia_restart_nb); |
73 | if (err) | |
74 | dev_err(dev, "cannot register restart handler (err=%d)\n", err); | |
4a315e34 | 75 | |
fcf01c51 | 76 | return err; |
4a315e34 AB |
77 | } |
78 | ||
79 | static const struct of_device_id of_axxia_reset_match[] = { | |
80 | { .compatible = "lsi,axm55xx-reset", }, | |
81 | {}, | |
82 | }; | |
83 | MODULE_DEVICE_TABLE(of, of_axxia_reset_match); | |
84 | ||
85 | static struct platform_driver axxia_reset_driver = { | |
86 | .probe = axxia_reset_probe, | |
87 | .driver = { | |
88 | .name = "axxia-reset", | |
89 | .of_match_table = of_match_ptr(of_axxia_reset_match), | |
90 | }, | |
91 | }; | |
92 | ||
93 | static int __init axxia_reset_init(void) | |
94 | { | |
95 | return platform_driver_register(&axxia_reset_driver); | |
96 | } | |
97 | device_initcall(axxia_reset_init); |