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115 lines
2.8 KiB
115 lines
2.8 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) STMicroelectronics 2018 - All Rights Reserved |
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* Author: Gabriel Fernandez <[email protected]> for STMicroelectronics. |
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*/ |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/io.h> |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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#include <linux/reset-controller.h> |
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#define CLR_OFFSET 0x4 |
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struct stm32_reset_data { |
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struct reset_controller_dev rcdev; |
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void __iomem *membase; |
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}; |
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static inline struct stm32_reset_data * |
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to_stm32_reset_data(struct reset_controller_dev *rcdev) |
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{ |
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return container_of(rcdev, struct stm32_reset_data, rcdev); |
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} |
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static int stm32_reset_update(struct reset_controller_dev *rcdev, |
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unsigned long id, bool assert) |
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{ |
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struct stm32_reset_data *data = to_stm32_reset_data(rcdev); |
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int reg_width = sizeof(u32); |
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int bank = id / (reg_width * BITS_PER_BYTE); |
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int offset = id % (reg_width * BITS_PER_BYTE); |
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void __iomem *addr; |
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addr = data->membase + (bank * reg_width); |
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if (!assert) |
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addr += CLR_OFFSET; |
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writel(BIT(offset), addr); |
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return 0; |
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} |
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static int stm32_reset_assert(struct reset_controller_dev *rcdev, |
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unsigned long id) |
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{ |
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return stm32_reset_update(rcdev, id, true); |
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} |
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static int stm32_reset_deassert(struct reset_controller_dev *rcdev, |
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unsigned long id) |
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{ |
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return stm32_reset_update(rcdev, id, false); |
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} |
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static int stm32_reset_status(struct reset_controller_dev *rcdev, |
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unsigned long id) |
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{ |
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struct stm32_reset_data *data = to_stm32_reset_data(rcdev); |
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int reg_width = sizeof(u32); |
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int bank = id / (reg_width * BITS_PER_BYTE); |
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int offset = id % (reg_width * BITS_PER_BYTE); |
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u32 reg; |
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reg = readl(data->membase + (bank * reg_width)); |
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return !!(reg & BIT(offset)); |
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} |
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static const struct reset_control_ops stm32_reset_ops = { |
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.assert = stm32_reset_assert, |
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.deassert = stm32_reset_deassert, |
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.status = stm32_reset_status, |
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}; |
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static const struct of_device_id stm32_reset_dt_ids[] = { |
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{ .compatible = "st,stm32mp1-rcc"}, |
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{ /* sentinel */ }, |
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}; |
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static int stm32_reset_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct stm32_reset_data *data; |
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void __iomem *membase; |
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struct resource *res; |
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data = devm_kzalloc(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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membase = devm_ioremap_resource(dev, res); |
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if (IS_ERR(membase)) |
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return PTR_ERR(membase); |
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data->membase = membase; |
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data->rcdev.owner = THIS_MODULE; |
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data->rcdev.nr_resets = resource_size(res) * BITS_PER_BYTE; |
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data->rcdev.ops = &stm32_reset_ops; |
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data->rcdev.of_node = dev->of_node; |
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return devm_reset_controller_register(dev, &data->rcdev); |
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} |
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static struct platform_driver stm32_reset_driver = { |
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.probe = stm32_reset_probe, |
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.driver = { |
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.name = "stm32mp1-reset", |
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.of_match_table = stm32_reset_dt_ids, |
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}, |
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}; |
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builtin_platform_driver(stm32_reset_driver);
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