| 1 | |
| 2 | * Copyright (C) 2014 Marvell Technology Group Ltd.
|
| 3 | *
|
| 4 | * Marvell Berlin reset driver
|
| 5 | *
|
| 6 | * Antoine Tenart <[email protected]>
|
| 7 | * Sebastian Hesselbarth <[email protected]>
|
| 8 | *
|
| 9 | * This file is licensed under the terms of the GNU General Public
|
| 10 | * License version 2. This program is licensed "as is" without any
|
| 11 | * warranty of any kind, whether express or implied.
|
| 12 |
|
| 13 |
|
| 14 | #include <linux/delay.h>
|
| 15 | #include <linux/io.h>
|
| 16 | #include <linux/mfd/syscon.h>
|
| 17 | #include <linux/module.h>
|
| 18 | #include <linux/of.h>
|
| 19 | #include <linux/of_address.h>
|
| 20 | #include <linux/platform_device.h>
|
| 21 | #include <linux/regmap.h>
|
| 22 | #include <linux/reset-controller.h>
|
| 23 | #include <linux/slab.h>
|
| 24 | #include <linux/types.h>
|
| 25 |
|
| 26 | #define BERLIN_MAX_RESETS 32
|
| 27 |
|
| 28 | #define to_berlin_reset_priv(p) \
|
| 29 | container_of((p), struct berlin_reset_priv, rcdev)
|
| 30 |
|
| 31 | struct berlin_reset_priv {
|
| 32 | struct regmap *regmap;
|
| 33 | struct reset_controller_dev rcdev;
|
| 34 | };
|
| 35 |
|
| 36 | static int berlin_reset_reset(struct reset_controller_dev *rcdev,
|
| 37 | unsigned long id)
|
| 38 | {
|
| 39 | struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
|
| 40 | int offset = id >> 8;
|
| 41 | int mask = BIT(id & 0x1f);
|
| 42 |
|
| 43 | regmap_write(priv->regmap, offset, mask);
|
| 44 |
|
| 45 |
|
| 46 | udelay(10);
|
| 47 |
|
| 48 | return 0;
|
| 49 | }
|
| 50 |
|
| 51 | static const struct reset_control_ops berlin_reset_ops = {
|
| 52 | .reset = berlin_reset_reset,
|
| 53 | };
|
| 54 |
|
| 55 | static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
|
| 56 | const struct of_phandle_args *reset_spec)
|
| 57 | {
|
| 58 | unsigned int offset, bit;
|
| 59 |
|
| 60 | offset = reset_spec->args[0];
|
| 61 | bit = reset_spec->args[1];
|
| 62 |
|
| 63 | if (bit >= BERLIN_MAX_RESETS)
|
| 64 | return -EINVAL;
|
| 65 |
|
| 66 | return (offset << 8) | bit;
|
| 67 | }
|
| 68 |
|
| 69 | static int berlin2_reset_probe(struct platform_device *pdev)
|
| 70 | {
|
| 71 | struct device_node *parent_np;
|
| 72 | struct berlin_reset_priv *priv;
|
| 73 |
|
| 74 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
|
| 75 | if (!priv)
|
| 76 | return -ENOMEM;
|
| 77 |
|
| 78 | parent_np = of_get_parent(pdev->dev.of_node);
|
| 79 | priv->regmap = syscon_node_to_regmap(parent_np);
|
| 80 | of_node_put(parent_np);
|
| 81 | if (IS_ERR(priv->regmap))
|
| 82 | return PTR_ERR(priv->regmap);
|
| 83 |
|
| 84 | priv->rcdev.owner = THIS_MODULE;
|
| 85 | priv->rcdev.ops = &berlin_reset_ops;
|
| 86 | priv->rcdev.of_node = pdev->dev.of_node;
|
| 87 | priv->rcdev.of_reset_n_cells = 2;
|
| 88 | priv->rcdev.of_xlate = berlin_reset_xlate;
|
| 89 |
|
| 90 | return reset_controller_register(&priv->rcdev);
|
| 91 | }
|
| 92 |
|
| 93 | static const struct of_device_id berlin_reset_dt_match[] = {
|
| 94 | { .compatible = "marvell,berlin2-reset" },
|
| 95 | { },
|
| 96 | };
|
| 97 | MODULE_DEVICE_TABLE(of, berlin_reset_dt_match);
|
| 98 |
|
| 99 | static struct platform_driver berlin_reset_driver = {
|
| 100 | .probe = berlin2_reset_probe,
|
| 101 | .driver = {
|
| 102 | .name = "berlin2-reset",
|
| 103 | .of_match_table = berlin_reset_dt_match,
|
| 104 | },
|
| 105 | };
|
| 106 | module_platform_driver(berlin_reset_driver);
|
| 107 |
|
| 108 | MODULE_AUTHOR("Antoine Tenart <[email protected]>");
|
| 109 | MODULE_AUTHOR("Sebastian Hesselbarth <[email protected]>");
|
| 110 | MODULE_DESCRIPTION("Synaptics Berlin reset controller");
|
| 111 | MODULE_LICENSE("GPL");
|