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https://github.com/AsahiLinux/u-boot
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038b13ee81
This patch adds a generic reset driver. It is designed to be useful when one has a register in a regmap which contains bits that reset other devices. I thought this seemed like a very generic use, so here is a generic driver. The overall structure has been modeled on the syscon-reboot driver. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org>
81 lines
1.9 KiB
C
81 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2020 Sean Anderson
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*/
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#include <common.h>
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#include <dm.h>
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#include <regmap.h>
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#include <reset.h>
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#include <reset-uclass.h>
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#include <syscon.h>
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#include <linux/bitops.h>
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#include <linux/err.h>
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struct syscon_reset_priv {
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struct regmap *regmap;
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uint offset;
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uint mask;
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bool assert_high;
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};
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static int syscon_reset_request(struct reset_ctl *rst)
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{
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struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
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if (BIT(rst->id) & priv->mask)
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return 0;
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else
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return -EINVAL;
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}
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static int syscon_reset_assert(struct reset_ctl *rst)
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{
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struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
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return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id),
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priv->assert_high ? BIT(rst->id) : 0);
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}
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static int syscon_reset_deassert(struct reset_ctl *rst)
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{
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struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
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return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id),
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priv->assert_high ? 0 : BIT(rst->id));
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}
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static const struct reset_ops syscon_reset_ops = {
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.request = syscon_reset_request,
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.rst_assert = syscon_reset_assert,
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.rst_deassert = syscon_reset_deassert,
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};
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int syscon_reset_probe(struct udevice *dev)
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{
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struct syscon_reset_priv *priv = dev_get_priv(dev);
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priv->regmap = syscon_regmap_lookup_by_phandle(dev, "regmap");
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if (IS_ERR(priv->regmap))
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return -ENODEV;
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priv->offset = dev_read_u32_default(dev, "offset", 0);
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priv->mask = dev_read_u32_default(dev, "mask", 0);
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priv->assert_high = dev_read_u32_default(dev, "assert-high", true);
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return 0;
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}
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static const struct udevice_id syscon_reset_ids[] = {
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{ .compatible = "syscon-reset" },
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{ },
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};
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U_BOOT_DRIVER(syscon_reset) = {
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.name = "syscon_reset",
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.id = UCLASS_RESET,
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.of_match = syscon_reset_ids,
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.probe = syscon_reset_probe,
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.priv_auto_alloc_size = sizeof(struct syscon_reset_priv),
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.ops = &syscon_reset_ops,
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};
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