linux/drivers/clk/clk-composite.c
Mike Turquette 5a994e151f clk: composite: improve rate_hw sanity check logic
The function pointer population and sanity checking logic got a bit ugly
with the advent of the .determine_rate callback. Clean it up.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-07-13 12:17:05 -07:00

288 lines
7.8 KiB
C

/*
* Copyright (c) 2013 NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/slab.h>
#define to_clk_composite(_hw) container_of(_hw, struct clk_composite, hw)
static u8 clk_composite_get_parent(struct clk_hw *hw)
{
struct clk_composite *composite = to_clk_composite(hw);
const struct clk_ops *mux_ops = composite->mux_ops;
struct clk_hw *mux_hw = composite->mux_hw;
mux_hw->clk = hw->clk;
return mux_ops->get_parent(mux_hw);
}
static int clk_composite_set_parent(struct clk_hw *hw, u8 index)
{
struct clk_composite *composite = to_clk_composite(hw);
const struct clk_ops *mux_ops = composite->mux_ops;
struct clk_hw *mux_hw = composite->mux_hw;
mux_hw->clk = hw->clk;
return mux_ops->set_parent(mux_hw, index);
}
static unsigned long clk_composite_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_composite *composite = to_clk_composite(hw);
const struct clk_ops *rate_ops = composite->rate_ops;
struct clk_hw *rate_hw = composite->rate_hw;
rate_hw->clk = hw->clk;
return rate_ops->recalc_rate(rate_hw, parent_rate);
}
static long clk_composite_determine_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *best_parent_rate,
struct clk **best_parent_p)
{
struct clk_composite *composite = to_clk_composite(hw);
const struct clk_ops *rate_ops = composite->rate_ops;
const struct clk_ops *mux_ops = composite->mux_ops;
struct clk_hw *rate_hw = composite->rate_hw;
struct clk_hw *mux_hw = composite->mux_hw;
struct clk *parent;
unsigned long parent_rate;
long tmp_rate, best_rate = 0;
unsigned long rate_diff;
unsigned long best_rate_diff = ULONG_MAX;
int i;
if (rate_hw && rate_ops && rate_ops->determine_rate) {
rate_hw->clk = hw->clk;
return rate_ops->determine_rate(rate_hw, rate, best_parent_rate,
best_parent_p);
} else if (rate_hw && rate_ops && rate_ops->round_rate &&
mux_hw && mux_ops && mux_ops->set_parent) {
*best_parent_p = NULL;
if (__clk_get_flags(hw->clk) & CLK_SET_RATE_NO_REPARENT) {
*best_parent_p = clk_get_parent(mux_hw->clk);
*best_parent_rate = __clk_get_rate(*best_parent_p);
return rate_ops->round_rate(rate_hw, rate,
best_parent_rate);
}
for (i = 0; i < __clk_get_num_parents(mux_hw->clk); i++) {
parent = clk_get_parent_by_index(mux_hw->clk, i);
if (!parent)
continue;
parent_rate = __clk_get_rate(parent);
tmp_rate = rate_ops->round_rate(rate_hw, rate,
&parent_rate);
if (tmp_rate < 0)
continue;
rate_diff = abs(rate - tmp_rate);
if (!rate_diff || !*best_parent_p
|| best_rate_diff > rate_diff) {
*best_parent_p = parent;
*best_parent_rate = parent_rate;
best_rate_diff = rate_diff;
best_rate = tmp_rate;
}
if (!rate_diff)
return rate;
}
return best_rate;
} else if (mux_hw && mux_ops && mux_ops->determine_rate) {
mux_hw->clk = hw->clk;
return mux_ops->determine_rate(mux_hw, rate, best_parent_rate,
best_parent_p);
} else {
pr_err("clk: clk_composite_determine_rate function called, but no mux or rate callback set!\n");
return 0;
}
}
static long clk_composite_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct clk_composite *composite = to_clk_composite(hw);
const struct clk_ops *rate_ops = composite->rate_ops;
struct clk_hw *rate_hw = composite->rate_hw;
rate_hw->clk = hw->clk;
return rate_ops->round_rate(rate_hw, rate, prate);
}
static int clk_composite_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_composite *composite = to_clk_composite(hw);
const struct clk_ops *rate_ops = composite->rate_ops;
struct clk_hw *rate_hw = composite->rate_hw;
rate_hw->clk = hw->clk;
return rate_ops->set_rate(rate_hw, rate, parent_rate);
}
static int clk_composite_is_enabled(struct clk_hw *hw)
{
struct clk_composite *composite = to_clk_composite(hw);
const struct clk_ops *gate_ops = composite->gate_ops;
struct clk_hw *gate_hw = composite->gate_hw;
gate_hw->clk = hw->clk;
return gate_ops->is_enabled(gate_hw);
}
static int clk_composite_enable(struct clk_hw *hw)
{
struct clk_composite *composite = to_clk_composite(hw);
const struct clk_ops *gate_ops = composite->gate_ops;
struct clk_hw *gate_hw = composite->gate_hw;
gate_hw->clk = hw->clk;
return gate_ops->enable(gate_hw);
}
static void clk_composite_disable(struct clk_hw *hw)
{
struct clk_composite *composite = to_clk_composite(hw);
const struct clk_ops *gate_ops = composite->gate_ops;
struct clk_hw *gate_hw = composite->gate_hw;
gate_hw->clk = hw->clk;
gate_ops->disable(gate_hw);
}
struct clk *clk_register_composite(struct device *dev, const char *name,
const char **parent_names, int num_parents,
struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
unsigned long flags)
{
struct clk *clk;
struct clk_init_data init;
struct clk_composite *composite;
struct clk_ops *clk_composite_ops;
composite = kzalloc(sizeof(*composite), GFP_KERNEL);
if (!composite) {
pr_err("%s: could not allocate composite clk\n", __func__);
return ERR_PTR(-ENOMEM);
}
init.name = name;
init.flags = flags | CLK_IS_BASIC;
init.parent_names = parent_names;
init.num_parents = num_parents;
clk_composite_ops = &composite->ops;
if (mux_hw && mux_ops) {
if (!mux_ops->get_parent) {
clk = ERR_PTR(-EINVAL);
goto err;
}
composite->mux_hw = mux_hw;
composite->mux_ops = mux_ops;
clk_composite_ops->get_parent = clk_composite_get_parent;
if (mux_ops->set_parent)
clk_composite_ops->set_parent = clk_composite_set_parent;
if (mux_ops->determine_rate)
clk_composite_ops->determine_rate = clk_composite_determine_rate;
}
if (rate_hw && rate_ops) {
if (!rate_ops->recalc_rate) {
clk = ERR_PTR(-EINVAL);
goto err;
}
clk_composite_ops->recalc_rate = clk_composite_recalc_rate;
if (rate_ops->determine_rate)
clk_composite_ops->determine_rate =
clk_composite_determine_rate;
else if (rate_ops->round_rate)
clk_composite_ops->round_rate =
clk_composite_round_rate;
/* .set_rate requires either .round_rate or .determine_rate */
if (rate_ops->set_rate) {
if (rate_ops->determine_rate || rate_ops->round_rate)
clk_composite_ops->set_rate =
clk_composite_set_rate;
else
WARN(1, "%s: missing round_rate op is required\n",
__func__);
}
composite->rate_hw = rate_hw;
composite->rate_ops = rate_ops;
}
if (gate_hw && gate_ops) {
if (!gate_ops->is_enabled || !gate_ops->enable ||
!gate_ops->disable) {
clk = ERR_PTR(-EINVAL);
goto err;
}
composite->gate_hw = gate_hw;
composite->gate_ops = gate_ops;
clk_composite_ops->is_enabled = clk_composite_is_enabled;
clk_composite_ops->enable = clk_composite_enable;
clk_composite_ops->disable = clk_composite_disable;
}
init.ops = clk_composite_ops;
composite->hw.init = &init;
clk = clk_register(dev, &composite->hw);
if (IS_ERR(clk))
goto err;
if (composite->mux_hw)
composite->mux_hw->clk = clk;
if (composite->rate_hw)
composite->rate_hw->clk = clk;
if (composite->gate_hw)
composite->gate_hw->clk = clk;
return clk;
err:
kfree(composite);
return clk;
}