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5da672cff0
Until now we were not providing a way to read back the status of our
reset controls. Consumers had no real way to be certain whether a
peripheral was held in reset or not.
Implement the status callback to complete the API support.
Fixes: 1d80c14248 ("clk: sunxi-ng: Add common infrastructure")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
82 lines
2.0 KiB
C
82 lines
2.0 KiB
C
/*
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* Copyright (C) 2016 Maxime Ripard
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* Maxime Ripard <maxime.ripard@free-electrons.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*/
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <linux/reset-controller.h>
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#include "ccu_reset.h"
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static int ccu_reset_assert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
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const struct ccu_reset_map *map = &ccu->reset_map[id];
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unsigned long flags;
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u32 reg;
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spin_lock_irqsave(ccu->lock, flags);
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reg = readl(ccu->base + map->reg);
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writel(reg & ~map->bit, ccu->base + map->reg);
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spin_unlock_irqrestore(ccu->lock, flags);
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return 0;
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}
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static int ccu_reset_deassert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
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const struct ccu_reset_map *map = &ccu->reset_map[id];
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unsigned long flags;
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u32 reg;
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spin_lock_irqsave(ccu->lock, flags);
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reg = readl(ccu->base + map->reg);
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writel(reg | map->bit, ccu->base + map->reg);
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spin_unlock_irqrestore(ccu->lock, flags);
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return 0;
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}
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static int ccu_reset_reset(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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ccu_reset_assert(rcdev, id);
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udelay(10);
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ccu_reset_deassert(rcdev, id);
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return 0;
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}
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static int ccu_reset_status(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
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const struct ccu_reset_map *map = &ccu->reset_map[id];
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/*
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* The reset control API expects 0 if reset is not asserted,
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* which is the opposite of what our hardware uses.
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*/
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return !(map->bit & readl(ccu->base + map->reg));
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}
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const struct reset_control_ops ccu_reset_ops = {
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.assert = ccu_reset_assert,
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.deassert = ccu_reset_deassert,
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.reset = ccu_reset_reset,
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.status = ccu_reset_status,
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};
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