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/*
* rz Core CPG Clocks
*
* Copyright (C) 2013 Ideas On Board SPRL
* Copyright (C) 2014 Wolfram Sang, Sang Engineering <wsa@sang-engineering.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; version 2 of the License.
*/
#include <linux/clk-provider.h>
#include <linux/clk/renesas.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/slab.h>
struct rz_cpg {
struct clk_onecell_data data;
void __iomem *reg;
};
#define CPG_FRQCR 0x10
#define CPG_FRQCR2 0x14
/* -----------------------------------------------------------------------------
* Initialization
*/
static struct clk * __init
rz_cpg_register_clock(struct device_node *np, struct rz_cpg *cpg, const char *name)
{
u32 val;
unsigned mult;
static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 };
if (strcmp(name, "pll") == 0) {
/* FIXME: cpg_mode should be read from GPIO. But no GPIO support yet */
unsigned cpg_mode = 0; /* hardcoded to EXTAL for now */
const char *parent_name = of_clk_get_parent_name(np, cpg_mode);
mult = cpg_mode ? (32 / 4) : 30;
return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, 1);
}
/* If mapping regs failed, skip non-pll clocks. System will boot anyhow */
if (!cpg->reg)
return ERR_PTR(-ENXIO);
/* FIXME:"i" and "g" are variable clocks with non-integer dividers (e.g. 2/3)
* and the constraint that always g <= i. To get the rz platform started,
* let them run at fixed current speed and implement the details later.
*/
if (strcmp(name, "i") == 0)
val = (clk_readl(cpg->reg + CPG_FRQCR) >> 8) & 3;
else if (strcmp(name, "g") == 0)
val = clk_readl(cpg->reg + CPG_FRQCR2) & 3;
else
return ERR_PTR(-EINVAL);
mult = frqcr_tab[val];
return clk_register_fixed_factor(NULL, name, "pll", 0, mult, 3);
}
static void __init rz_cpg_clocks_init(struct device_node *np)
{
struct rz_cpg *cpg;
struct clk **clks;
unsigned i;
int num_clks;
num_clks = of_property_count_strings(np, "clock-output-names");
if (WARN(num_clks <= 0, "can't count CPG clocks\n"))
return;
cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL);
BUG_ON(!cpg || !clks);
cpg->data.clks = clks;
cpg->data.clk_num = num_clks;
cpg->reg = of_iomap(np, 0);
for (i = 0; i < num_clks; ++i) {
const char *name;
struct clk *clk;
of_property_read_string_index(np, "clock-output-names", i, &name);
clk = rz_cpg_register_clock(np, cpg, name);
if (IS_ERR(clk))
pr_err("%s: failed to register %s %s clock (%ld)\n",
__func__, np->name, name, PTR_ERR(clk));
else
cpg->data.clks[i] = clk;
}
of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
cpg_mstp_add_clk_domain(np);
}
CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init);
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