mirror of
https://github.com/torvalds/linux.git
synced 2024-11-29 23:51:37 +00:00
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
/*
|
|
* Copyright (C) 2016 Maxime Ripard
|
|
* Maxime Ripard <maxime.ripard@free-electrons.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation; either version 2 of
|
|
* the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/io.h>
|
|
#include <linux/reset-controller.h>
|
|
|
|
#include "ccu_reset.h"
|
|
|
|
static int ccu_reset_assert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
|
|
const struct ccu_reset_map *map = &ccu->reset_map[id];
|
|
unsigned long flags;
|
|
u32 reg;
|
|
|
|
spin_lock_irqsave(ccu->lock, flags);
|
|
|
|
reg = readl(ccu->base + map->reg);
|
|
writel(reg & ~map->bit, ccu->base + map->reg);
|
|
|
|
spin_unlock_irqrestore(ccu->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ccu_reset_deassert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
|
|
const struct ccu_reset_map *map = &ccu->reset_map[id];
|
|
unsigned long flags;
|
|
u32 reg;
|
|
|
|
spin_lock_irqsave(ccu->lock, flags);
|
|
|
|
reg = readl(ccu->base + map->reg);
|
|
writel(reg | map->bit, ccu->base + map->reg);
|
|
|
|
spin_unlock_irqrestore(ccu->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ccu_reset_reset(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
ccu_reset_assert(rcdev, id);
|
|
udelay(10);
|
|
ccu_reset_deassert(rcdev, id);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ccu_reset_status(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
|
|
const struct ccu_reset_map *map = &ccu->reset_map[id];
|
|
|
|
/*
|
|
* The reset control API expects 0 if reset is not asserted,
|
|
* which is the opposite of what our hardware uses.
|
|
*/
|
|
return !(map->bit & readl(ccu->base + map->reg));
|
|
}
|
|
|
|
const struct reset_control_ops ccu_reset_ops = {
|
|
.assert = ccu_reset_assert,
|
|
.deassert = ccu_reset_deassert,
|
|
.reset = ccu_reset_reset,
|
|
.status = ccu_reset_status,
|
|
};
|