linux-zen-server/drivers/clk/renesas/clk-rz.c

122 lines
3.0 KiB
C
Raw Permalink Normal View History

2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0
/*
* RZ/A1 Core CPG Clocks
*
* Copyright (C) 2013 Ideas On Board SPRL
* Copyright (C) 2014 Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
*/
#include <linux/clk-provider.h>
#include <linux/clk/renesas.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#define CPG_FRQCR 0x10
#define CPG_FRQCR2 0x14
#define PPR0 0xFCFE3200
#define PIBC0 0xFCFE7000
#define MD_CLK(x) ((x >> 2) & 1) /* P0_2 */
/* -----------------------------------------------------------------------------
* Initialization
*/
static u16 __init rz_cpg_read_mode_pins(void)
{
void __iomem *ppr0, *pibc0;
u16 modes;
ppr0 = ioremap(PPR0, 2);
pibc0 = ioremap(PIBC0, 2);
BUG_ON(!ppr0 || !pibc0);
iowrite16(4, pibc0); /* enable input buffer */
modes = ioread16(ppr0);
iounmap(ppr0);
iounmap(pibc0);
return modes;
}
static struct clk * __init
rz_cpg_register_clock(struct device_node *np, void __iomem *base,
const char *name)
{
u32 val;
unsigned mult;
static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 };
if (strcmp(name, "pll") == 0) {
unsigned int cpg_mode = MD_CLK(rz_cpg_read_mode_pins());
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 (!base)
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 = (readl(base + CPG_FRQCR) >> 8) & 3;
else if (strcmp(name, "g") == 0)
val = readl(base + 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 clk_onecell_data *data;
struct clk **clks;
void __iomem *base;
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;
data = kzalloc(sizeof(*data), GFP_KERNEL);
clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
BUG_ON(!data || !clks);
data->clks = clks;
data->clk_num = num_clks;
base = 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, base, name);
if (IS_ERR(clk))
pr_err("%s: failed to register %pOFn %s clock (%ld)\n",
__func__, np, name, PTR_ERR(clk));
else
data->clks[i] = clk;
}
of_clk_add_provider(np, of_clk_src_onecell_get, data);
cpg_mstp_add_clk_domain(np);
}
CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init);