kernel/drivers/clk/ti/composite.c
2024-07-22 17:22:30 +08:00

279 lines
6.6 KiB
C

/*
* TI composite clock support
*
* Copyright (C) 2013 Texas Instruments, Inc.
*
* Tero Kristo <t-kristo@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk-provider.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/clk/ti.h>
#include <linux/list.h>
#include "clock.h"
#undef pr_fmt
#define pr_fmt(fmt) "%s: " fmt, __func__
static unsigned long ti_composite_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
return ti_clk_divider_ops.recalc_rate(hw, parent_rate);
}
static long ti_composite_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
return -EINVAL;
}
static int ti_composite_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
return -EINVAL;
}
static const struct clk_ops ti_composite_divider_ops = {
.recalc_rate = &ti_composite_recalc_rate,
.round_rate = &ti_composite_round_rate,
.set_rate = &ti_composite_set_rate,
};
static const struct clk_ops ti_composite_gate_ops = {
.enable = &omap2_dflt_clk_enable,
.disable = &omap2_dflt_clk_disable,
.is_enabled = &omap2_dflt_clk_is_enabled,
};
struct component_clk {
int num_parents;
const char **parent_names;
struct device_node *node;
int type;
struct clk_hw *hw;
struct list_head link;
};
static const char * const component_clk_types[] __initconst = {
"gate", "divider", "mux"
};
static LIST_HEAD(component_clks);
static struct device_node *_get_component_node(struct device_node *node, int i)
{
int rc;
struct of_phandle_args clkspec;
rc = of_parse_phandle_with_args(node, "clocks", "#clock-cells", i,
&clkspec);
if (rc)
return NULL;
return clkspec.np;
}
static struct component_clk *_lookup_component(struct device_node *node)
{
struct component_clk *comp;
list_for_each_entry(comp, &component_clks, link) {
if (comp->node == node)
return comp;
}
return NULL;
}
struct clk_hw_omap_comp {
struct clk_hw hw;
struct device_node *comp_nodes[CLK_COMPONENT_TYPE_MAX];
struct component_clk *comp_clks[CLK_COMPONENT_TYPE_MAX];
};
static inline struct clk_hw *_get_hw(struct clk_hw_omap_comp *clk, int idx)
{
if (!clk)
return NULL;
if (!clk->comp_clks[idx])
return NULL;
return clk->comp_clks[idx]->hw;
}
#define to_clk_hw_comp(_hw) container_of(_hw, struct clk_hw_omap_comp, hw)
static void __init _register_composite(void *user,
struct device_node *node)
{
struct clk_hw *hw = user;
struct clk *clk;
struct clk_hw_omap_comp *cclk = to_clk_hw_comp(hw);
struct component_clk *comp;
int num_parents = 0;
const char **parent_names = NULL;
const char *name;
int i;
int ret;
/* Check for presence of each component clock */
for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
if (!cclk->comp_nodes[i])
continue;
comp = _lookup_component(cclk->comp_nodes[i]);
if (!comp) {
pr_debug("component %s not ready for %pOFn, retry\n",
cclk->comp_nodes[i]->name, node);
if (!ti_clk_retry_init(node, hw,
_register_composite))
return;
goto cleanup;
}
if (cclk->comp_clks[comp->type] != NULL) {
pr_err("duplicate component types for %pOFn (%s)!\n",
node, component_clk_types[comp->type]);
goto cleanup;
}
cclk->comp_clks[comp->type] = comp;
/* Mark this node as found */
cclk->comp_nodes[i] = NULL;
}
/* All components exists, proceed with registration */
for (i = CLK_COMPONENT_TYPE_MAX - 1; i >= 0; i--) {
comp = cclk->comp_clks[i];
if (!comp)
continue;
if (comp->num_parents) {
num_parents = comp->num_parents;
parent_names = comp->parent_names;
break;
}
}
if (!num_parents) {
pr_err("%s: no parents found for %pOFn!\n", __func__, node);
goto cleanup;
}
name = ti_dt_clk_name(node);
clk = clk_register_composite(NULL, name,
parent_names, num_parents,
_get_hw(cclk, CLK_COMPONENT_TYPE_MUX),
&ti_clk_mux_ops,
_get_hw(cclk, CLK_COMPONENT_TYPE_DIVIDER),
&ti_composite_divider_ops,
_get_hw(cclk, CLK_COMPONENT_TYPE_GATE),
&ti_composite_gate_ops, 0);
if (!IS_ERR(clk)) {
ret = ti_clk_add_alias(clk, name);
if (ret) {
clk_unregister(clk);
goto cleanup;
}
of_clk_add_provider(node, of_clk_src_simple_get, clk);
}
cleanup:
/* Free component clock list entries */
for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
if (!cclk->comp_clks[i])
continue;
list_del(&cclk->comp_clks[i]->link);
kfree(cclk->comp_clks[i]->parent_names);
kfree(cclk->comp_clks[i]);
}
kfree(cclk);
}
static void __init of_ti_composite_clk_setup(struct device_node *node)
{
unsigned int num_clks;
int i;
struct clk_hw_omap_comp *cclk;
/* Number of component clocks to be put inside this clock */
num_clks = of_clk_get_parent_count(node);
if (!num_clks) {
pr_err("composite clk %pOFn must have component(s)\n", node);
return;
}
cclk = kzalloc(sizeof(*cclk), GFP_KERNEL);
if (!cclk)
return;
/* Get device node pointers for each component clock */
for (i = 0; i < num_clks; i++)
cclk->comp_nodes[i] = _get_component_node(node, i);
_register_composite(&cclk->hw, node);
}
CLK_OF_DECLARE(ti_composite_clock, "ti,composite-clock",
of_ti_composite_clk_setup);
/**
* ti_clk_add_component - add a component clock to the pool
* @node: device node of the component clock
* @hw: hardware clock definition for the component clock
* @type: type of the component clock
*
* Adds a component clock to the list of available components, so that
* it can be registered by a composite clock.
*/
int __init ti_clk_add_component(struct device_node *node, struct clk_hw *hw,
int type)
{
unsigned int num_parents;
const char **parent_names;
struct component_clk *clk;
num_parents = of_clk_get_parent_count(node);
if (!num_parents) {
pr_err("component-clock %pOFn must have parent(s)\n", node);
return -EINVAL;
}
parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL);
if (!parent_names)
return -ENOMEM;
of_clk_parent_fill(node, parent_names, num_parents);
clk = kzalloc(sizeof(*clk), GFP_KERNEL);
if (!clk) {
kfree(parent_names);
return -ENOMEM;
}
clk->num_parents = num_parents;
clk->parent_names = parent_names;
clk->hw = hw;
clk->node = node;
clk->type = type;
list_add(&clk->link, &component_clks);
return 0;
}