Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 1 | /* |
Paul Gortmaker | 8290924 | 2017-02-07 19:18:46 -0500 | [diff] [blame] | 2 | * Amlogic Meson Reset Controller driver |
| 3 | * |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 4 | * This file is provided under a dual BSD/GPLv2 license. When using or |
| 5 | * redistributing this file, you may do so under either license. |
| 6 | * |
| 7 | * GPL LICENSE SUMMARY |
| 8 | * |
| 9 | * Copyright (c) 2016 BayLibre, SAS. |
| 10 | * Author: Neil Armstrong <narmstrong@baylibre.com> |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of version 2 of the GNU General Public License as |
| 14 | * published by the Free Software Foundation. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, but |
| 17 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 19 | * General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU General Public License |
| 22 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| 23 | * The full GNU General Public License is included in this distribution |
| 24 | * in the file called COPYING. |
| 25 | * |
| 26 | * BSD LICENSE |
| 27 | * |
| 28 | * Copyright (c) 2016 BayLibre, SAS. |
| 29 | * Author: Neil Armstrong <narmstrong@baylibre.com> |
| 30 | * |
| 31 | * Redistribution and use in source and binary forms, with or without |
| 32 | * modification, are permitted provided that the following conditions |
| 33 | * are met: |
| 34 | * |
| 35 | * * Redistributions of source code must retain the above copyright |
| 36 | * notice, this list of conditions and the following disclaimer. |
| 37 | * * Redistributions in binary form must reproduce the above copyright |
| 38 | * notice, this list of conditions and the following disclaimer in |
| 39 | * the documentation and/or other materials provided with the |
| 40 | * distribution. |
| 41 | * * Neither the name of Intel Corporation nor the names of its |
| 42 | * contributors may be used to endorse or promote products derived |
| 43 | * from this software without specific prior written permission. |
| 44 | * |
| 45 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 46 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 47 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 48 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 49 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 50 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 51 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 52 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 53 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 54 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 55 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 56 | */ |
| 57 | #include <linux/err.h> |
Paul Gortmaker | 8290924 | 2017-02-07 19:18:46 -0500 | [diff] [blame] | 58 | #include <linux/init.h> |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 59 | #include <linux/io.h> |
| 60 | #include <linux/of.h> |
| 61 | #include <linux/platform_device.h> |
| 62 | #include <linux/reset-controller.h> |
| 63 | #include <linux/slab.h> |
| 64 | #include <linux/types.h> |
Neil Armstrong | a5a10af | 2017-10-17 12:19:18 +0200 | [diff] [blame] | 65 | #include <linux/of_device.h> |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 66 | |
| 67 | #define REG_COUNT 8 |
| 68 | #define BITS_PER_REG 32 |
Neil Armstrong | a5a10af | 2017-10-17 12:19:18 +0200 | [diff] [blame] | 69 | #define LEVEL_OFFSET 0x7c |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 70 | |
| 71 | struct meson_reset { |
| 72 | void __iomem *reg_base; |
| 73 | struct reset_controller_dev rcdev; |
Neil Armstrong | a5a10af | 2017-10-17 12:19:18 +0200 | [diff] [blame] | 74 | spinlock_t lock; |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 75 | }; |
| 76 | |
| 77 | static int meson_reset_reset(struct reset_controller_dev *rcdev, |
| 78 | unsigned long id) |
| 79 | { |
| 80 | struct meson_reset *data = |
| 81 | container_of(rcdev, struct meson_reset, rcdev); |
| 82 | unsigned int bank = id / BITS_PER_REG; |
| 83 | unsigned int offset = id % BITS_PER_REG; |
| 84 | void __iomem *reg_addr = data->reg_base + (bank << 2); |
| 85 | |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 86 | writel(BIT(offset), reg_addr); |
| 87 | |
| 88 | return 0; |
| 89 | } |
| 90 | |
Neil Armstrong | a5a10af | 2017-10-17 12:19:18 +0200 | [diff] [blame] | 91 | static int meson_reset_level(struct reset_controller_dev *rcdev, |
| 92 | unsigned long id, bool assert) |
| 93 | { |
| 94 | struct meson_reset *data = |
| 95 | container_of(rcdev, struct meson_reset, rcdev); |
| 96 | unsigned int bank = id / BITS_PER_REG; |
| 97 | unsigned int offset = id % BITS_PER_REG; |
| 98 | void __iomem *reg_addr = data->reg_base + LEVEL_OFFSET + (bank << 2); |
| 99 | unsigned long flags; |
| 100 | u32 reg; |
| 101 | |
| 102 | spin_lock_irqsave(&data->lock, flags); |
| 103 | |
| 104 | reg = readl(reg_addr); |
| 105 | if (assert) |
| 106 | writel(reg & ~BIT(offset), reg_addr); |
| 107 | else |
| 108 | writel(reg | BIT(offset), reg_addr); |
| 109 | |
| 110 | spin_unlock_irqrestore(&data->lock, flags); |
| 111 | |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | static int meson_reset_assert(struct reset_controller_dev *rcdev, |
| 116 | unsigned long id) |
| 117 | { |
| 118 | return meson_reset_level(rcdev, id, true); |
| 119 | } |
| 120 | |
| 121 | static int meson_reset_deassert(struct reset_controller_dev *rcdev, |
| 122 | unsigned long id) |
| 123 | { |
| 124 | return meson_reset_level(rcdev, id, false); |
| 125 | } |
| 126 | |
Martin Blumenstingl | 320da78 | 2017-12-26 12:50:41 +0100 | [diff] [blame] | 127 | static const struct reset_control_ops meson_reset_ops = { |
Neil Armstrong | a5a10af | 2017-10-17 12:19:18 +0200 | [diff] [blame] | 128 | .reset = meson_reset_reset, |
| 129 | .assert = meson_reset_assert, |
| 130 | .deassert = meson_reset_deassert, |
| 131 | }; |
| 132 | |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 133 | static const struct of_device_id meson_reset_dt_ids[] = { |
Martin Blumenstingl | 320da78 | 2017-12-26 12:50:41 +0100 | [diff] [blame] | 134 | { .compatible = "amlogic,meson8b-reset" }, |
| 135 | { .compatible = "amlogic,meson-gxbb-reset" }, |
| 136 | { .compatible = "amlogic,meson-axg-reset" }, |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 137 | { /* sentinel */ }, |
| 138 | }; |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 139 | |
| 140 | static int meson_reset_probe(struct platform_device *pdev) |
| 141 | { |
| 142 | struct meson_reset *data; |
| 143 | struct resource *res; |
| 144 | |
| 145 | data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); |
| 146 | if (!data) |
| 147 | return -ENOMEM; |
| 148 | |
| 149 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 150 | data->reg_base = devm_ioremap_resource(&pdev->dev, res); |
| 151 | if (IS_ERR(data->reg_base)) |
| 152 | return PTR_ERR(data->reg_base); |
| 153 | |
| 154 | platform_set_drvdata(pdev, data); |
| 155 | |
Neil Armstrong | a5a10af | 2017-10-17 12:19:18 +0200 | [diff] [blame] | 156 | spin_lock_init(&data->lock); |
| 157 | |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 158 | data->rcdev.owner = THIS_MODULE; |
| 159 | data->rcdev.nr_resets = REG_COUNT * BITS_PER_REG; |
Martin Blumenstingl | 320da78 | 2017-12-26 12:50:41 +0100 | [diff] [blame] | 160 | data->rcdev.ops = &meson_reset_ops; |
Neil Armstrong | c7224dc | 2016-05-30 15:27:15 +0200 | [diff] [blame] | 161 | data->rcdev.of_node = pdev->dev.of_node; |
| 162 | |
| 163 | return devm_reset_controller_register(&pdev->dev, &data->rcdev); |
| 164 | } |
| 165 | |
| 166 | static struct platform_driver meson_reset_driver = { |
| 167 | .probe = meson_reset_probe, |
| 168 | .driver = { |
| 169 | .name = "meson_reset", |
| 170 | .of_match_table = meson_reset_dt_ids, |
| 171 | }, |
| 172 | }; |
Paul Gortmaker | 8290924 | 2017-02-07 19:18:46 -0500 | [diff] [blame] | 173 | builtin_platform_driver(meson_reset_driver); |