linux/drivers/clk/zynqmp/clk-mux-zynqmp.c

139 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Zynq UltraScale+ MPSoC mux
*
* Copyright (C) 2016-2018 Xilinx
*/
#include <linux/clk-provider.h>
#include <linux/slab.h>
#include "clk-zynqmp.h"
/*
* DOC: basic adjustable multiplexer clock that cannot gate
*
* Traits of this clock:
* prepare - clk_prepare only ensures that parents are prepared
* enable - clk_enable only ensures that parents are enabled
* rate - rate is only affected by parent switching. No clk_set_rate support
* parent - parent is adjustable through clk_set_parent
*/
/**
* struct zynqmp_clk_mux - multiplexer clock
*
* @hw: handle between common and hardware-specific interfaces
* @flags: hardware-specific flags
* @clk_id: Id of clock
*/
struct zynqmp_clk_mux {
struct clk_hw hw;
u8 flags;
u32 clk_id;
};
#define to_zynqmp_clk_mux(_hw) container_of(_hw, struct zynqmp_clk_mux, hw)
/**
* zynqmp_clk_mux_get_parent() - Get parent of clock
* @hw: handle between common and hardware-specific interfaces
*
* Return: Parent index
*/
static u8 zynqmp_clk_mux_get_parent(struct clk_hw *hw)
{
struct zynqmp_clk_mux *mux = to_zynqmp_clk_mux(hw);
const char *clk_name = clk_hw_get_name(hw);
u32 clk_id = mux->clk_id;
u32 val;
int ret;
ret = zynqmp_pm_clock_getparent(clk_id, &val);
if (ret)
pr_warn_once("%s() getparent failed for clock: %s, ret = %d\n",
__func__, clk_name, ret);
return val;
}
/**
* zynqmp_clk_mux_set_parent() - Set parent of clock
* @hw: handle between common and hardware-specific interfaces
* @index: Parent index
*
* Return: 0 on success else error+reason
*/
static int zynqmp_clk_mux_set_parent(struct clk_hw *hw, u8 index)
{
struct zynqmp_clk_mux *mux = to_zynqmp_clk_mux(hw);
const char *clk_name = clk_hw_get_name(hw);
u32 clk_id = mux->clk_id;
int ret;
ret = zynqmp_pm_clock_setparent(clk_id, index);
if (ret)
pr_warn_once("%s() set parent failed for clock: %s, ret = %d\n",
__func__, clk_name, ret);
return ret;
}
static const struct clk_ops zynqmp_clk_mux_ops = {
.get_parent = zynqmp_clk_mux_get_parent,
.set_parent = zynqmp_clk_mux_set_parent,
.determine_rate = __clk_mux_determine_rate,
};
static const struct clk_ops zynqmp_clk_mux_ro_ops = {
.get_parent = zynqmp_clk_mux_get_parent,
};
/**
* zynqmp_clk_register_mux() - Register a mux table with the clock
* framework
* @name: Name of this clock
* @clk_id: Id of this clock
* @parents: Name of this clock's parents
* @num_parents: Number of parents
* @nodes: Clock topology node
*
* Return: clock hardware of the registered clock mux
*/
struct clk_hw *zynqmp_clk_register_mux(const char *name, u32 clk_id,
const char * const *parents,
u8 num_parents,
const struct clock_topology *nodes)
{
struct zynqmp_clk_mux *mux;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
mux = kzalloc(sizeof(*mux), GFP_KERNEL);
if (!mux)
return ERR_PTR(-ENOMEM);
init.name = name;
if (nodes->type_flag & CLK_MUX_READ_ONLY)
init.ops = &zynqmp_clk_mux_ro_ops;
else
init.ops = &zynqmp_clk_mux_ops;
init.flags = nodes->flag;
init.parent_names = parents;
init.num_parents = num_parents;
mux->flags = nodes->type_flag;
mux->hw.init = &init;
mux->clk_id = clk_id;
hw = &mux->hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(hw);
hw = ERR_PTR(ret);
}
return hw;
}