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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 | /* * Copyright (C) 2014 Marvell Technology Group Ltd. * * Antoine Tenart <antoine.tenart@free-electrons.com> * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/delay.h> #include <linux/io.h> #include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/platform_device.h> #include <linux/regmap.h> #include <linux/reset-controller.h> #include <linux/slab.h> #include <linux/types.h> #define BERLIN_MAX_RESETS 32 #define to_berlin_reset_priv(p) \ container_of((p), struct berlin_reset_priv, rcdev) struct berlin_reset_priv { struct regmap *regmap; struct reset_controller_dev rcdev; }; static int berlin_reset_reset(struct reset_controller_dev *rcdev, unsigned long id) { struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev); int offset = id >> 8; int mask = BIT(id & 0x1f); regmap_write(priv->regmap, offset, mask); /* let the reset be effective */ udelay(10); return 0; } static struct reset_control_ops berlin_reset_ops = { .reset = berlin_reset_reset, }; static int berlin_reset_xlate(struct reset_controller_dev *rcdev, const struct of_phandle_args *reset_spec) { unsigned offset, bit; if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells)) return -EINVAL; offset = reset_spec->args[0]; bit = reset_spec->args[1]; if (bit >= BERLIN_MAX_RESETS) return -EINVAL; return (offset << 8) | bit; } static int berlin2_reset_probe(struct platform_device *pdev) { struct device_node *parent_np = of_get_parent(pdev->dev.of_node); struct berlin_reset_priv *priv; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->regmap = syscon_node_to_regmap(parent_np); of_node_put(parent_np); if (IS_ERR(priv->regmap)) return PTR_ERR(priv->regmap); priv->rcdev.owner = THIS_MODULE; priv->rcdev.ops = &berlin_reset_ops; priv->rcdev.of_node = pdev->dev.of_node; priv->rcdev.of_reset_n_cells = 2; priv->rcdev.of_xlate = berlin_reset_xlate; reset_controller_register(&priv->rcdev); return 0; } static const struct of_device_id berlin_reset_dt_match[] = { { .compatible = "marvell,berlin2-reset" }, { }, }; MODULE_DEVICE_TABLE(of, berlin_reset_dt_match); static struct platform_driver berlin_reset_driver = { .probe = berlin2_reset_probe, .driver = { .name = "berlin2-reset", .of_match_table = berlin_reset_dt_match, }, }; module_platform_driver(berlin_reset_driver); MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); MODULE_AUTHOR("Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>"); MODULE_DESCRIPTION("Marvell Berlin reset driver"); MODULE_LICENSE("GPL"); |