mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 09:02:00 +00:00
a665962e8f
Signed-off-by: Wolfram Sang <wsa@sang-engineering.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
104 lines
2.8 KiB
C
104 lines
2.8 KiB
C
/*
|
|
* 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/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);
|
|
}
|
|
CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init);
|