1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * Copyright (C) 2014 Marvell Technology Group Ltd.
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * Marvell Berlin reset driver
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * Antoine Tenart <antoine.tenart@free-electrons.com>
7*4882a593Smuzhiyun * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
8*4882a593Smuzhiyun *
9*4882a593Smuzhiyun * This file is licensed under the terms of the GNU General Public
10*4882a593Smuzhiyun * License version 2. This program is licensed "as is" without any
11*4882a593Smuzhiyun * warranty of any kind, whether express or implied.
12*4882a593Smuzhiyun */
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun #include <linux/delay.h>
15*4882a593Smuzhiyun #include <linux/io.h>
16*4882a593Smuzhiyun #include <linux/mfd/syscon.h>
17*4882a593Smuzhiyun #include <linux/init.h>
18*4882a593Smuzhiyun #include <linux/of.h>
19*4882a593Smuzhiyun #include <linux/of_address.h>
20*4882a593Smuzhiyun #include <linux/platform_device.h>
21*4882a593Smuzhiyun #include <linux/regmap.h>
22*4882a593Smuzhiyun #include <linux/reset-controller.h>
23*4882a593Smuzhiyun #include <linux/slab.h>
24*4882a593Smuzhiyun #include <linux/types.h>
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun #define BERLIN_MAX_RESETS 32
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun #define to_berlin_reset_priv(p) \
29*4882a593Smuzhiyun container_of((p), struct berlin_reset_priv, rcdev)
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun struct berlin_reset_priv {
32*4882a593Smuzhiyun struct regmap *regmap;
33*4882a593Smuzhiyun struct reset_controller_dev rcdev;
34*4882a593Smuzhiyun };
35*4882a593Smuzhiyun
berlin_reset_reset(struct reset_controller_dev * rcdev,unsigned long id)36*4882a593Smuzhiyun static int berlin_reset_reset(struct reset_controller_dev *rcdev,
37*4882a593Smuzhiyun unsigned long id)
38*4882a593Smuzhiyun {
39*4882a593Smuzhiyun struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
40*4882a593Smuzhiyun int offset = id >> 8;
41*4882a593Smuzhiyun int mask = BIT(id & 0x1f);
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun regmap_write(priv->regmap, offset, mask);
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun /* let the reset be effective */
46*4882a593Smuzhiyun udelay(10);
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun return 0;
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun static const struct reset_control_ops berlin_reset_ops = {
52*4882a593Smuzhiyun .reset = berlin_reset_reset,
53*4882a593Smuzhiyun };
54*4882a593Smuzhiyun
berlin_reset_xlate(struct reset_controller_dev * rcdev,const struct of_phandle_args * reset_spec)55*4882a593Smuzhiyun static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
56*4882a593Smuzhiyun const struct of_phandle_args *reset_spec)
57*4882a593Smuzhiyun {
58*4882a593Smuzhiyun unsigned offset, bit;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun offset = reset_spec->args[0];
61*4882a593Smuzhiyun bit = reset_spec->args[1];
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun if (bit >= BERLIN_MAX_RESETS)
64*4882a593Smuzhiyun return -EINVAL;
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun return (offset << 8) | bit;
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun
berlin2_reset_probe(struct platform_device * pdev)69*4882a593Smuzhiyun static int berlin2_reset_probe(struct platform_device *pdev)
70*4882a593Smuzhiyun {
71*4882a593Smuzhiyun struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
72*4882a593Smuzhiyun struct berlin_reset_priv *priv;
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
75*4882a593Smuzhiyun if (!priv)
76*4882a593Smuzhiyun return -ENOMEM;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun priv->regmap = syscon_node_to_regmap(parent_np);
79*4882a593Smuzhiyun of_node_put(parent_np);
80*4882a593Smuzhiyun if (IS_ERR(priv->regmap))
81*4882a593Smuzhiyun return PTR_ERR(priv->regmap);
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun priv->rcdev.owner = THIS_MODULE;
84*4882a593Smuzhiyun priv->rcdev.ops = &berlin_reset_ops;
85*4882a593Smuzhiyun priv->rcdev.of_node = pdev->dev.of_node;
86*4882a593Smuzhiyun priv->rcdev.of_reset_n_cells = 2;
87*4882a593Smuzhiyun priv->rcdev.of_xlate = berlin_reset_xlate;
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun return reset_controller_register(&priv->rcdev);
90*4882a593Smuzhiyun }
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun static const struct of_device_id berlin_reset_dt_match[] = {
93*4882a593Smuzhiyun { .compatible = "marvell,berlin2-reset" },
94*4882a593Smuzhiyun { },
95*4882a593Smuzhiyun };
96*4882a593Smuzhiyun
97*4882a593Smuzhiyun static struct platform_driver berlin_reset_driver = {
98*4882a593Smuzhiyun .probe = berlin2_reset_probe,
99*4882a593Smuzhiyun .driver = {
100*4882a593Smuzhiyun .name = "berlin2-reset",
101*4882a593Smuzhiyun .of_match_table = berlin_reset_dt_match,
102*4882a593Smuzhiyun },
103*4882a593Smuzhiyun };
104*4882a593Smuzhiyun builtin_platform_driver(berlin_reset_driver);
105