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151 lines
3.8 KiB
151 lines
3.8 KiB
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause |
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/* |
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* Amlogic Meson Reset Controller driver |
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* |
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* Copyright (c) 2016 BayLibre, SAS. |
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* Author: Neil Armstrong <[email protected]> |
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*/ |
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#include <linux/err.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <linux/of.h> |
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#include <linux/module.h> |
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#include <linux/platform_device.h> |
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#include <linux/reset-controller.h> |
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#include <linux/slab.h> |
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#include <linux/types.h> |
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#include <linux/of_device.h> |
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#define BITS_PER_REG 32 |
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struct meson_reset_param { |
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int reg_count; |
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int level_offset; |
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}; |
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struct meson_reset { |
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void __iomem *reg_base; |
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const struct meson_reset_param *param; |
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struct reset_controller_dev rcdev; |
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spinlock_t lock; |
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}; |
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static int meson_reset_reset(struct reset_controller_dev *rcdev, |
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unsigned long id) |
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{ |
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struct meson_reset *data = |
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container_of(rcdev, struct meson_reset, rcdev); |
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unsigned int bank = id / BITS_PER_REG; |
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unsigned int offset = id % BITS_PER_REG; |
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void __iomem *reg_addr = data->reg_base + (bank << 2); |
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writel(BIT(offset), reg_addr); |
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return 0; |
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} |
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static int meson_reset_level(struct reset_controller_dev *rcdev, |
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unsigned long id, bool assert) |
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{ |
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struct meson_reset *data = |
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container_of(rcdev, struct meson_reset, rcdev); |
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unsigned int bank = id / BITS_PER_REG; |
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unsigned int offset = id % BITS_PER_REG; |
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void __iomem *reg_addr; |
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unsigned long flags; |
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u32 reg; |
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reg_addr = data->reg_base + data->param->level_offset + (bank << 2); |
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spin_lock_irqsave(&data->lock, flags); |
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reg = readl(reg_addr); |
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if (assert) |
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writel(reg & ~BIT(offset), reg_addr); |
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else |
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writel(reg | BIT(offset), reg_addr); |
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spin_unlock_irqrestore(&data->lock, flags); |
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return 0; |
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} |
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static int meson_reset_assert(struct reset_controller_dev *rcdev, |
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unsigned long id) |
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{ |
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return meson_reset_level(rcdev, id, true); |
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} |
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static int meson_reset_deassert(struct reset_controller_dev *rcdev, |
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unsigned long id) |
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{ |
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return meson_reset_level(rcdev, id, false); |
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} |
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static const struct reset_control_ops meson_reset_ops = { |
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.reset = meson_reset_reset, |
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.assert = meson_reset_assert, |
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.deassert = meson_reset_deassert, |
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}; |
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static const struct meson_reset_param meson8b_param = { |
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.reg_count = 8, |
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.level_offset = 0x7c, |
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}; |
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static const struct meson_reset_param meson_a1_param = { |
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.reg_count = 3, |
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.level_offset = 0x40, |
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}; |
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static const struct of_device_id meson_reset_dt_ids[] = { |
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{ .compatible = "amlogic,meson8b-reset", .data = &meson8b_param}, |
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{ .compatible = "amlogic,meson-gxbb-reset", .data = &meson8b_param}, |
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{ .compatible = "amlogic,meson-axg-reset", .data = &meson8b_param}, |
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{ .compatible = "amlogic,meson-a1-reset", .data = &meson_a1_param}, |
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{ /* sentinel */ }, |
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}; |
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MODULE_DEVICE_TABLE(of, meson_reset_dt_ids); |
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static int meson_reset_probe(struct platform_device *pdev) |
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{ |
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struct meson_reset *data; |
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struct resource *res; |
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data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); |
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if (!data) |
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return -ENOMEM; |
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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data->reg_base = devm_ioremap_resource(&pdev->dev, res); |
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if (IS_ERR(data->reg_base)) |
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return PTR_ERR(data->reg_base); |
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data->param = of_device_get_match_data(&pdev->dev); |
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if (!data->param) |
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return -ENODEV; |
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platform_set_drvdata(pdev, data); |
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spin_lock_init(&data->lock); |
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data->rcdev.owner = THIS_MODULE; |
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data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG; |
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data->rcdev.ops = &meson_reset_ops; |
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data->rcdev.of_node = pdev->dev.of_node; |
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return devm_reset_controller_register(&pdev->dev, &data->rcdev); |
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} |
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static struct platform_driver meson_reset_driver = { |
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.probe = meson_reset_probe, |
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.driver = { |
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.name = "meson_reset", |
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.of_match_table = meson_reset_dt_ids, |
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}, |
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}; |
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module_platform_driver(meson_reset_driver); |
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MODULE_DESCRIPTION("Amlogic Meson Reset Controller driver"); |
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MODULE_AUTHOR("Neil Armstrong <[email protected]>"); |
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MODULE_LICENSE("Dual BSD/GPL");
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