376349232a
ARC AXS10x boards support custom IP-block which allows to control reset signals of selected peripherals. For example DW GMAC, etc... This block is controlled via memory-mapped register (AKA CREG) which represents up-to 32 reset lines. This regiter is self-clearing so we don't need to deassert line after reset. As of today only the following lines are used: - DW GMAC - line 5 Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
83 lines
2 KiB
C
83 lines
2 KiB
C
/*
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* Copyright (C) 2017 Synopsys.
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*
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* Synopsys AXS10x reset driver.
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/io.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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#define to_axs10x_rst(p) container_of((p), struct axs10x_rst, rcdev)
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#define AXS10X_MAX_RESETS 32
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struct axs10x_rst {
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void __iomem *regs_rst;
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spinlock_t lock;
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struct reset_controller_dev rcdev;
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};
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static int axs10x_reset_reset(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct axs10x_rst *rst = to_axs10x_rst(rcdev);
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unsigned long flags;
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spin_lock_irqsave(&rst->lock, flags);
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writel(BIT(id), rst->regs_rst);
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spin_unlock_irqrestore(&rst->lock, flags);
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return 0;
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}
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static const struct reset_control_ops axs10x_reset_ops = {
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.reset = axs10x_reset_reset,
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};
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static int axs10x_reset_probe(struct platform_device *pdev)
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{
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struct axs10x_rst *rst;
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struct resource *mem;
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rst = devm_kzalloc(&pdev->dev, sizeof(*rst), GFP_KERNEL);
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if (!rst)
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return -ENOMEM;
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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rst->regs_rst = devm_ioremap_resource(&pdev->dev, mem);
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if (IS_ERR(rst->regs_rst))
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return PTR_ERR(rst->regs_rst);
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spin_lock_init(&rst->lock);
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rst->rcdev.owner = THIS_MODULE;
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rst->rcdev.ops = &axs10x_reset_ops;
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rst->rcdev.of_node = pdev->dev.of_node;
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rst->rcdev.nr_resets = AXS10X_MAX_RESETS;
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return devm_reset_controller_register(&pdev->dev, &rst->rcdev);
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}
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static const struct of_device_id axs10x_reset_dt_match[] = {
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{ .compatible = "snps,axs10x-reset" },
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{ },
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};
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static struct platform_driver axs10x_reset_driver = {
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.probe = axs10x_reset_probe,
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.driver = {
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.name = "axs10x-reset",
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.of_match_table = axs10x_reset_dt_match,
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},
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};
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builtin_platform_driver(axs10x_reset_driver);
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MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>");
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MODULE_DESCRIPTION("Synopsys AXS10x reset driver");
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MODULE_LICENSE("GPL v2");
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