| Antoine Ténart | bd13251 | 2014-09-03 09:48:20 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2014 Marvell Technology Group Ltd. |
| 3 | * |
| 4 | * Antoine Tenart <antoine.tenart@free-electrons.com> |
| 5 | * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> |
| 6 | * |
| 7 | * This file is licensed under the terms of the GNU General Public |
| 8 | * License version 2. This program is licensed "as is" without any |
| 9 | * warranty of any kind, whether express or implied. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/delay.h> |
| 13 | #include <linux/io.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/of.h> |
| 16 | #include <linux/of_address.h> |
| 17 | #include <linux/platform_device.h> |
| 18 | #include <linux/reset-controller.h> |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/types.h> |
| 21 | |
| 22 | #define BERLIN_MAX_RESETS 32 |
| 23 | |
| 24 | #define to_berlin_reset_priv(p) \ |
| 25 | container_of((p), struct berlin_reset_priv, rcdev) |
| 26 | |
| 27 | struct berlin_reset_priv { |
| 28 | void __iomem *base; |
| 29 | unsigned int size; |
| 30 | struct reset_controller_dev rcdev; |
| 31 | }; |
| 32 | |
| 33 | static int berlin_reset_reset(struct reset_controller_dev *rcdev, |
| 34 | unsigned long id) |
| 35 | { |
| 36 | struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev); |
| 37 | int offset = id >> 8; |
| 38 | int mask = BIT(id & 0x1f); |
| 39 | |
| 40 | writel(mask, priv->base + offset); |
| 41 | |
| 42 | /* let the reset be effective */ |
| 43 | udelay(10); |
| 44 | |
| 45 | return 0; |
| 46 | } |
| 47 | |
| 48 | static struct reset_control_ops berlin_reset_ops = { |
| 49 | .reset = berlin_reset_reset, |
| 50 | }; |
| 51 | |
| 52 | static int berlin_reset_xlate(struct reset_controller_dev *rcdev, |
| 53 | const struct of_phandle_args *reset_spec) |
| 54 | { |
| 55 | struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev); |
| 56 | unsigned offset, bit; |
| 57 | |
| 58 | if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells)) |
| 59 | return -EINVAL; |
| 60 | |
| 61 | offset = reset_spec->args[0]; |
| 62 | bit = reset_spec->args[1]; |
| 63 | |
| 64 | if (offset >= priv->size) |
| 65 | return -EINVAL; |
| 66 | |
| 67 | if (bit >= BERLIN_MAX_RESETS) |
| 68 | return -EINVAL; |
| 69 | |
| 70 | return (offset << 8) | bit; |
| 71 | } |
| 72 | |
| 73 | static int __berlin_reset_init(struct device_node *np) |
| 74 | { |
| 75 | struct berlin_reset_priv *priv; |
| 76 | struct resource res; |
| 77 | resource_size_t size; |
| 78 | int ret; |
| 79 | |
| 80 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); |
| 81 | if (!priv) |
| 82 | return -ENOMEM; |
| 83 | |
| 84 | ret = of_address_to_resource(np, 0, &res); |
| 85 | if (ret) |
| 86 | goto err; |
| 87 | |
| 88 | size = resource_size(&res); |
| 89 | priv->base = ioremap(res.start, size); |
| 90 | if (!priv->base) { |
| 91 | ret = -ENOMEM; |
| 92 | goto err; |
| 93 | } |
| 94 | priv->size = size; |
| 95 | |
| 96 | priv->rcdev.owner = THIS_MODULE; |
| 97 | priv->rcdev.ops = &berlin_reset_ops; |
| 98 | priv->rcdev.of_node = np; |
| 99 | priv->rcdev.of_reset_n_cells = 2; |
| 100 | priv->rcdev.of_xlate = berlin_reset_xlate; |
| 101 | |
| 102 | reset_controller_register(&priv->rcdev); |
| 103 | |
| 104 | return 0; |
| 105 | |
| 106 | err: |
| 107 | kfree(priv); |
| 108 | return ret; |
| 109 | } |
| 110 | |
| 111 | static const struct of_device_id berlin_reset_of_match[] __initconst = { |
| 112 | { .compatible = "marvell,berlin2-chip-ctrl" }, |
| 113 | { .compatible = "marvell,berlin2cd-chip-ctrl" }, |
| 114 | { .compatible = "marvell,berlin2q-chip-ctrl" }, |
| 115 | { }, |
| 116 | }; |
| 117 | |
| 118 | static int __init berlin_reset_init(void) |
| 119 | { |
| 120 | struct device_node *np; |
| 121 | int ret; |
| 122 | |
| 123 | for_each_matching_node(np, berlin_reset_of_match) { |
| 124 | ret = __berlin_reset_init(np); |
| 125 | if (ret) |
| 126 | return ret; |
| 127 | } |
| 128 | |
| 129 | return 0; |
| 130 | } |
| 131 | arch_initcall(berlin_reset_init); |