OpenCloudOS-Kernel/drivers/clk/st/clkgen-mux.c

109 lines
2.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* clkgen-mux.c: ST GEN-MUX Clock driver
*
* Copyright (C) 2014 STMicroelectronics (R&D) Limited
*
* Authors: Stephen Gallimore <stephen.gallimore@st.com>
* Pankaj Dev <pankaj.dev@st.com>
*/
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include "clkgen.h"
static const char ** __init clkgen_mux_get_parents(struct device_node *np,
int *num_parents)
{
const char **parents;
unsigned int nparents;
nparents = of_clk_get_parent_count(np);
if (WARN_ON(!nparents))
return ERR_PTR(-EINVAL);
parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL);
if (!parents)
return ERR_PTR(-ENOMEM);
*num_parents = of_clk_parent_fill(np, parents, nparents);
return parents;
}
struct clkgen_mux_data {
u32 offset;
u8 shift;
u8 width;
spinlock_t *lock;
unsigned long clk_flags;
u8 mux_flags;
};
static struct clkgen_mux_data stih407_a9_mux_data = {
.offset = 0x1a4,
.shift = 0,
.width = 2,
.lock = &clkgen_a9_lock,
};
static void __init st_of_clkgen_mux_setup(struct device_node *np,
struct clkgen_mux_data *data)
{
struct clk *clk;
void __iomem *reg;
const char **parents;
int num_parents = 0;
/*
* First check for reg property within the node to keep backward
* compatibility, then if reg doesn't exist look at the parent node
*/
reg = of_iomap(np, 0);
if (!reg) {
reg = of_iomap(of_get_parent(np), 0);
if (!reg) {
pr_err("%s: Failed to get base address\n", __func__);
return;
}
}
parents = clkgen_mux_get_parents(np, &num_parents);
if (IS_ERR(parents)) {
pr_err("%s: Failed to get parents (%ld)\n",
__func__, PTR_ERR(parents));
goto err_parents;
}
clk = clk_register_mux(NULL, np->name, parents, num_parents,
data->clk_flags | CLK_SET_RATE_PARENT,
reg + data->offset,
data->shift, data->width, data->mux_flags,
data->lock);
if (IS_ERR(clk))
goto err;
pr_debug("%s: parent %s rate %u\n",
__clk_get_name(clk),
__clk_get_name(clk_get_parent(clk)),
(unsigned int)clk_get_rate(clk));
kfree(parents);
of_clk_add_provider(np, of_clk_src_simple_get, clk);
return;
err:
kfree(parents);
err_parents:
iounmap(reg);
}
static void __init st_of_clkgen_a9_mux_setup(struct device_node *np)
{
st_of_clkgen_mux_setup(np, &stih407_a9_mux_data);
}
CLK_OF_DECLARE(clkgen_a9mux, "st,stih407-clkgen-a9-mux",
st_of_clkgen_a9_mux_setup);