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/*
* Copyright (C) 2016-2017 Imagination Technologies
* Author: Paul Burton <paul.burton@mips.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#define pr_fmt(fmt) "clk-boston: " fmt
#include <linux/clk-provider.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/mfd/syscon.h>
#include <dt-bindings/clock/boston-clock.h>
#define BOSTON_PLAT_MMCMDIV 0x30
# define BOSTON_PLAT_MMCMDIV_CLK0DIV (0xff << 0)
# define BOSTON_PLAT_MMCMDIV_INPUT (0xff << 8)
# define BOSTON_PLAT_MMCMDIV_MUL (0xff << 16)
# define BOSTON_PLAT_MMCMDIV_CLK1DIV (0xff << 24)
#define BOSTON_CLK_COUNT 3
static u32 ext_field(u32 val, u32 mask)
{
return (val & mask) >> (ffs(mask) - 1);
}
static void __init clk_boston_setup(struct device_node *np)
{
unsigned long in_freq, cpu_freq, sys_freq;
uint mmcmdiv, mul, cpu_div, sys_div;
struct clk_hw_onecell_data *onecell;
struct regmap *regmap;
struct clk_hw *hw;
int err;
regmap = syscon_node_to_regmap(np->parent);
if (IS_ERR(regmap)) {
pr_err("failed to find regmap\n");
return;
}
err = regmap_read(regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv);
if (err) {
pr_err("failed to read mmcm_div register: %d\n", err);
return;
}
in_freq = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT) * 1000000;
mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL);
sys_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV);
sys_freq = mult_frac(in_freq, mul, sys_div);
cpu_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV);
cpu_freq = mult_frac(in_freq, mul, cpu_div);
onecell = kzalloc(sizeof(*onecell) +
(BOSTON_CLK_COUNT * sizeof(struct clk_hw *)),
GFP_KERNEL);
if (!onecell)
return;
onecell->num = BOSTON_CLK_COUNT;
hw = clk_hw_register_fixed_rate(NULL, "input", NULL, 0, in_freq);
if (IS_ERR(hw)) {
pr_err("failed to register input clock: %ld\n", PTR_ERR(hw));
goto fail_input;
}
onecell->hws[BOSTON_CLK_INPUT] = hw;
hw = clk_hw_register_fixed_rate(NULL, "sys", "input", 0, sys_freq);
if (IS_ERR(hw)) {
pr_err("failed to register sys clock: %ld\n", PTR_ERR(hw));
goto fail_sys;
}
onecell->hws[BOSTON_CLK_SYS] = hw;
hw = clk_hw_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq);
if (IS_ERR(hw)) {
pr_err("failed to register cpu clock: %ld\n", PTR_ERR(hw));
goto fail_cpu;
}
onecell->hws[BOSTON_CLK_CPU] = hw;
err = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, onecell);
if (err) {
pr_err("failed to add DT provider: %d\n", err);
goto fail_clk_add;
}
return;
fail_clk_add:
clk_hw_unregister_fixed_rate(onecell->hws[BOSTON_CLK_CPU]);
fail_cpu:
clk_hw_unregister_fixed_rate(onecell->hws[BOSTON_CLK_SYS]);
fail_sys:
clk_hw_unregister_fixed_rate(onecell->hws[BOSTON_CLK_INPUT]);
fail_input:
kfree(onecell);
}
/*
* Use CLK_OF_DECLARE so that this driver is probed early enough to provide the
* CPU frequency for use with the GIC or cop0 counters/timers.
*/
CLK_OF_DECLARE(clk_boston, "img,boston-clock", clk_boston_setup);
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