2874c5fd28
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
124 lines
3 KiB
C
124 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright (C) 2016 Maxime Ripard
|
|
* Maxime Ripard <maxime.ripard@free-electrons.com>
|
|
*/
|
|
|
|
#include <linux/clk-provider.h>
|
|
#include <linux/io.h>
|
|
#include <linux/spinlock.h>
|
|
|
|
#include "ccu_phase.h"
|
|
|
|
static int ccu_phase_get_phase(struct clk_hw *hw)
|
|
{
|
|
struct ccu_phase *phase = hw_to_ccu_phase(hw);
|
|
struct clk_hw *parent, *grandparent;
|
|
unsigned int parent_rate, grandparent_rate;
|
|
u16 step, parent_div;
|
|
u32 reg;
|
|
u8 delay;
|
|
|
|
reg = readl(phase->common.base + phase->common.reg);
|
|
delay = (reg >> phase->shift);
|
|
delay &= (1 << phase->width) - 1;
|
|
|
|
if (!delay)
|
|
return 180;
|
|
|
|
/* Get our parent clock, it's the one that can adjust its rate */
|
|
parent = clk_hw_get_parent(hw);
|
|
if (!parent)
|
|
return -EINVAL;
|
|
|
|
/* And its rate */
|
|
parent_rate = clk_hw_get_rate(parent);
|
|
if (!parent_rate)
|
|
return -EINVAL;
|
|
|
|
/* Now, get our parent's parent (most likely some PLL) */
|
|
grandparent = clk_hw_get_parent(parent);
|
|
if (!grandparent)
|
|
return -EINVAL;
|
|
|
|
/* And its rate */
|
|
grandparent_rate = clk_hw_get_rate(grandparent);
|
|
if (!grandparent_rate)
|
|
return -EINVAL;
|
|
|
|
/* Get our parent clock divider */
|
|
parent_div = grandparent_rate / parent_rate;
|
|
|
|
step = DIV_ROUND_CLOSEST(360, parent_div);
|
|
return delay * step;
|
|
}
|
|
|
|
static int ccu_phase_set_phase(struct clk_hw *hw, int degrees)
|
|
{
|
|
struct ccu_phase *phase = hw_to_ccu_phase(hw);
|
|
struct clk_hw *parent, *grandparent;
|
|
unsigned int parent_rate, grandparent_rate;
|
|
unsigned long flags;
|
|
u32 reg;
|
|
u8 delay;
|
|
|
|
/* Get our parent clock, it's the one that can adjust its rate */
|
|
parent = clk_hw_get_parent(hw);
|
|
if (!parent)
|
|
return -EINVAL;
|
|
|
|
/* And its rate */
|
|
parent_rate = clk_hw_get_rate(parent);
|
|
if (!parent_rate)
|
|
return -EINVAL;
|
|
|
|
/* Now, get our parent's parent (most likely some PLL) */
|
|
grandparent = clk_hw_get_parent(parent);
|
|
if (!grandparent)
|
|
return -EINVAL;
|
|
|
|
/* And its rate */
|
|
grandparent_rate = clk_hw_get_rate(grandparent);
|
|
if (!grandparent_rate)
|
|
return -EINVAL;
|
|
|
|
if (degrees != 180) {
|
|
u16 step, parent_div;
|
|
|
|
/* Get our parent divider */
|
|
parent_div = grandparent_rate / parent_rate;
|
|
|
|
/*
|
|
* We can only outphase the clocks by multiple of the
|
|
* PLL's period.
|
|
*
|
|
* Since our parent clock is only a divider, and the
|
|
* formula to get the outphasing in degrees is deg =
|
|
* 360 * delta / period
|
|
*
|
|
* If we simplify this formula, we can see that the
|
|
* only thing that we're concerned about is the number
|
|
* of period we want to outphase our clock from, and
|
|
* the divider set by our parent clock.
|
|
*/
|
|
step = DIV_ROUND_CLOSEST(360, parent_div);
|
|
delay = DIV_ROUND_CLOSEST(degrees, step);
|
|
} else {
|
|
delay = 0;
|
|
}
|
|
|
|
spin_lock_irqsave(phase->common.lock, flags);
|
|
reg = readl(phase->common.base + phase->common.reg);
|
|
reg &= ~GENMASK(phase->width + phase->shift - 1, phase->shift);
|
|
writel(reg | (delay << phase->shift),
|
|
phase->common.base + phase->common.reg);
|
|
spin_unlock_irqrestore(phase->common.lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct clk_ops ccu_phase_ops = {
|
|
.get_phase = ccu_phase_get_phase,
|
|
.set_phase = ccu_phase_set_phase,
|
|
};
|