u-boot-brain/drivers/clk/clk-composite.c
Sean Anderson 78ce0bd3ac clk: Always use the supplied struct clk
CCF clocks should always use the struct clock passed to their methods for
extracting the driver-specific clock information struct. Previously, many
functions would use the clk->dev->priv if the device was bound. This could
cause problems with composite clocks. The individual clocks in a composite
clock did not have the ->dev field filled in. This was fine, because the
device-specific clock information would be used. However, since there was
no ->dev, there was no way to get the parent clock. This caused the
recalc_rate method of the CCF divider clock to fail. One option would be to
use the clk->priv field to get the composite clock and from there get the
appropriate parent device. However, this would tie the implementation to
the composite clock. In general, different devices should not rely on the
contents of ->priv from another device.

The simple solution to this problem is to just always use the supplied
struct clock. The composite clock now fills in the ->dev pointer of its
child clocks.  This allows child clocks to make calls like clk_get_parent()
without issue.

imx avoided the above problem by using a custom get_rate function with
composite clocks.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Acked-by: Lukasz Majewski <lukma@denx.de>
2020-07-01 15:01:21 +08:00

170 lines
4.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2013 NVIDIA CORPORATION. All rights reserved.
* Copyright 2019 NXP
*/
#include <common.h>
#include <asm/io.h>
#include <malloc.h>
#include <clk-uclass.h>
#include <dm/device.h>
#include <dm/devres.h>
#include <linux/clk-provider.h>
#include <clk.h>
#include <linux/err.h>
#include "clk.h"
#define UBOOT_DM_CLK_COMPOSITE "clk_composite"
static u8 clk_composite_get_parent(struct clk *clk)
{
struct clk_composite *composite = to_clk_composite(clk_dev_binded(clk) ?
(struct clk *)dev_get_clk_ptr(clk->dev) : clk);
struct clk *mux = composite->mux;
return clk_mux_get_parent(mux);
}
static int clk_composite_set_parent(struct clk *clk, struct clk *parent)
{
struct clk_composite *composite = to_clk_composite(clk_dev_binded(clk) ?
(struct clk *)dev_get_clk_ptr(clk->dev) : clk);
const struct clk_ops *mux_ops = composite->mux_ops;
struct clk *mux = composite->mux;
return mux_ops->set_parent(mux, parent);
}
static unsigned long clk_composite_recalc_rate(struct clk *clk)
{
struct clk_composite *composite = to_clk_composite(clk_dev_binded(clk) ?
(struct clk *)dev_get_clk_ptr(clk->dev) : clk);
const struct clk_ops *rate_ops = composite->rate_ops;
struct clk *rate = composite->rate;
return rate_ops->get_rate(rate);
}
static ulong clk_composite_set_rate(struct clk *clk, unsigned long rate)
{
struct clk_composite *composite = to_clk_composite(clk_dev_binded(clk) ?
(struct clk *)dev_get_clk_ptr(clk->dev) : clk);
const struct clk_ops *rate_ops = composite->rate_ops;
struct clk *clk_rate = composite->rate;
return rate_ops->set_rate(clk_rate, rate);
}
static int clk_composite_enable(struct clk *clk)
{
struct clk_composite *composite = to_clk_composite(clk_dev_binded(clk) ?
(struct clk *)dev_get_clk_ptr(clk->dev) : clk);
const struct clk_ops *gate_ops = composite->gate_ops;
struct clk *gate = composite->gate;
return gate_ops->enable(gate);
}
static int clk_composite_disable(struct clk *clk)
{
struct clk_composite *composite = to_clk_composite(clk_dev_binded(clk) ?
(struct clk *)dev_get_clk_ptr(clk->dev) : clk);
const struct clk_ops *gate_ops = composite->gate_ops;
struct clk *gate = composite->gate;
gate_ops->disable(gate);
return 0;
}
struct clk_ops clk_composite_ops = {
/* This will be set according to clk_register_composite */
};
struct clk *clk_register_composite(struct device *dev, const char *name,
const char * const *parent_names,
int num_parents, struct clk *mux,
const struct clk_ops *mux_ops,
struct clk *rate,
const struct clk_ops *rate_ops,
struct clk *gate,
const struct clk_ops *gate_ops,
unsigned long flags)
{
struct clk *clk;
struct clk_composite *composite;
int ret;
struct clk_ops *composite_ops = &clk_composite_ops;
composite = kzalloc(sizeof(*composite), GFP_KERNEL);
if (!composite)
return ERR_PTR(-ENOMEM);
if (mux && mux_ops) {
composite->mux = mux;
composite->mux_ops = mux_ops;
if (mux_ops->set_parent)
composite_ops->set_parent = clk_composite_set_parent;
mux->data = (ulong)composite;
}
if (rate && rate_ops) {
if (!rate_ops->get_rate) {
clk = ERR_PTR(-EINVAL);
goto err;
}
composite_ops->get_rate = clk_composite_recalc_rate;
/* .set_rate requires either .round_rate or .determine_rate */
if (rate_ops->set_rate)
composite_ops->set_rate = clk_composite_set_rate;
composite->rate = rate;
composite->rate_ops = rate_ops;
rate->data = (ulong)composite;
}
if (gate && gate_ops) {
if (!gate_ops->enable || !gate_ops->disable) {
clk = ERR_PTR(-EINVAL);
goto err;
}
composite->gate = gate;
composite->gate_ops = gate_ops;
composite_ops->enable = clk_composite_enable;
composite_ops->disable = clk_composite_disable;
gate->data = (ulong)composite;
}
clk = &composite->clk;
ret = clk_register(clk, UBOOT_DM_CLK_COMPOSITE, name,
parent_names[clk_composite_get_parent(clk)]);
if (ret) {
clk = ERR_PTR(ret);
goto err;
}
if (composite->mux)
composite->mux->dev = clk->dev;
if (composite->rate)
composite->rate->dev = clk->dev;
if (composite->gate)
composite->gate->dev = clk->dev;
return clk;
err:
kfree(composite);
return clk;
}
U_BOOT_DRIVER(clk_composite) = {
.name = UBOOT_DM_CLK_COMPOSITE,
.id = UCLASS_CLK,
.ops = &clk_composite_ops,
.flags = DM_FLAG_PRE_RELOC,
};