clk-periph.c
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/*
* Copyright 2011-2012 Calxeda, Inc.
* Copyright (C) 2012-2013 Altera Corporation <www.altera.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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Based from clk-highbank.c
*
*/
#include <linux/slab.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/of.h>
#include "clk.h"
#define to_socfpga_periph_clk(p) container_of(p, struct socfpga_periph_clk, hw.hw)
static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
unsigned long parent_rate)
{
struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk);
u32 div, val;
if (socfpgaclk->fixed_div) {
div = socfpgaclk->fixed_div;
} else {
if (socfpgaclk->div_reg) {
val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
val &= GENMASK(socfpgaclk->width - 1, 0);
parent_rate /= (val + 1);
}
div = ((readl(socfpgaclk->hw.reg) & 0x1ff) + 1);
}
return parent_rate / div;
}
static u8 clk_periclk_get_parent(struct clk_hw *hwclk)
{
u32 clk_src;
clk_src = readl(clk_mgr_base_addr + CLKMGR_DBCTRL);
return clk_src & 0x1;
}
static const struct clk_ops periclk_ops = {
.recalc_rate = clk_periclk_recalc_rate,
.get_parent = clk_periclk_get_parent,
};
static __init void __socfpga_periph_init(struct device_node *node,
const struct clk_ops *ops)
{
u32 reg;
struct clk *clk;
struct socfpga_periph_clk *periph_clk;
const char *clk_name = node->name;
const char *parent_name[SOCFPGA_MAX_PARENTS];
struct clk_init_data init;
int rc;
u32 fixed_div;
u32 div_reg[3];
of_property_read_u32(node, "reg", ®);
periph_clk = kzalloc(sizeof(*periph_clk), GFP_KERNEL);
if (WARN_ON(!periph_clk))
return;
periph_clk->hw.reg = clk_mgr_base_addr + reg;
rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
if (!rc) {
periph_clk->div_reg = clk_mgr_base_addr + div_reg[0];
periph_clk->shift = div_reg[1];
periph_clk->width = div_reg[2];
} else {
periph_clk->div_reg = NULL;
}
rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
if (rc)
periph_clk->fixed_div = 0;
else
periph_clk->fixed_div = fixed_div;
of_property_read_string(node, "clock-output-names", &clk_name);
init.name = clk_name;
init.ops = ops;
init.flags = 0;
init.num_parents = of_clk_parent_fill(node, parent_name,
SOCFPGA_MAX_PARENTS);
init.parent_names = parent_name;
periph_clk->hw.hw.init = &init;
clk = clk_register(NULL, &periph_clk->hw.hw);
if (WARN_ON(IS_ERR(clk))) {
kfree(periph_clk);
return;
}
rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
}
void __init socfpga_periph_init(struct device_node *node)
{
__socfpga_periph_init(node, &periclk_ops);
}