linux/drivers/clk/imx/clk-cpu.c
Anson Huang 870ed5e22a clk: imx: Support building i.MX common clock driver as module
There are more and more requirements of building SoC specific drivers
as modules, add support for building i.MX common clock driver as module
to meet the requirement.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2020-08-22 12:38:20 +08:00

109 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2014 Lucas Stach <l.stach@pengutronix.de>, Pengutronix
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/export.h>
#include <linux/slab.h>
#include "clk.h"
struct clk_cpu {
struct clk_hw hw;
struct clk *div;
struct clk *mux;
struct clk *pll;
struct clk *step;
};
static inline struct clk_cpu *to_clk_cpu(struct clk_hw *hw)
{
return container_of(hw, struct clk_cpu, hw);
}
static unsigned long clk_cpu_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_cpu *cpu = to_clk_cpu(hw);
return clk_get_rate(cpu->div);
}
static long clk_cpu_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct clk_cpu *cpu = to_clk_cpu(hw);
return clk_round_rate(cpu->pll, rate);
}
static int clk_cpu_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_cpu *cpu = to_clk_cpu(hw);
int ret;
/* switch to PLL bypass clock */
ret = clk_set_parent(cpu->mux, cpu->step);
if (ret)
return ret;
/* reprogram PLL */
ret = clk_set_rate(cpu->pll, rate);
if (ret) {
clk_set_parent(cpu->mux, cpu->pll);
return ret;
}
/* switch back to PLL clock */
clk_set_parent(cpu->mux, cpu->pll);
/* Ensure the divider is what we expect */
clk_set_rate(cpu->div, rate);
return 0;
}
static const struct clk_ops clk_cpu_ops = {
.recalc_rate = clk_cpu_recalc_rate,
.round_rate = clk_cpu_round_rate,
.set_rate = clk_cpu_set_rate,
};
struct clk_hw *imx_clk_hw_cpu(const char *name, const char *parent_name,
struct clk *div, struct clk *mux, struct clk *pll,
struct clk *step)
{
struct clk_cpu *cpu;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
cpu = kzalloc(sizeof(*cpu), GFP_KERNEL);
if (!cpu)
return ERR_PTR(-ENOMEM);
cpu->div = div;
cpu->mux = mux;
cpu->pll = pll;
cpu->step = step;
init.name = name;
init.ops = &clk_cpu_ops;
init.flags = CLK_IS_CRITICAL;
init.parent_names = &parent_name;
init.num_parents = 1;
cpu->hw.init = &init;
hw = &cpu->hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(cpu);
return ERR_PTR(ret);
}
return hw;
}
EXPORT_SYMBOL_GPL(imx_clk_hw_cpu);