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1/*2 * Copyright (C) 2014 Marvell Technology Group Ltd.3 *4 * Marvell Berlin reset driver5 *6 * Antoine Tenart <antoine.tenart@free-electrons.com>7 * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>8 *9 * This file is licensed under the terms of the GNU General Public10 * License version 2. This program is licensed "as is" without any11 * 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 3227 28#define to_berlin_reset_priv(p) \29 container_of((p), struct berlin_reset_priv, rcdev)30 31struct berlin_reset_priv {32 struct regmap *regmap;33 struct reset_controller_dev rcdev;34};35 36static 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 /* let the reset be effective */46 udelay(10);47 48 return 0;49}50 51static const struct reset_control_ops berlin_reset_ops = {52 .reset = berlin_reset_reset,53};54 55static 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 69static 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 93static const struct of_device_id berlin_reset_dt_match[] = {94 { .compatible = "marvell,berlin2-reset" },95 { },96};97MODULE_DEVICE_TABLE(of, berlin_reset_dt_match);98 99static 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};106module_platform_driver(berlin_reset_driver);107 108MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");109MODULE_AUTHOR("Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>");110MODULE_DESCRIPTION("Synaptics Berlin reset controller");111MODULE_LICENSE("GPL");112