linux/drivers/clk/renesas/clk-r8a73a4.c

241 lines
5.3 KiB
C

/*
* r8a73a4 Core CPG Clocks
*
* Copyright (C) 2014 Ulrich Hecht
*
* 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/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/spinlock.h>
struct r8a73a4_cpg {
struct clk_onecell_data data;
spinlock_t lock;
void __iomem *reg;
};
#define CPG_CKSCR 0xc0
#define CPG_FRQCRA 0x00
#define CPG_FRQCRB 0x04
#define CPG_FRQCRC 0xe0
#define CPG_PLL0CR 0xd8
#define CPG_PLL1CR 0x28
#define CPG_PLL2CR 0x2c
#define CPG_PLL2HCR 0xe4
#define CPG_PLL2SCR 0xf4
#define CLK_ENABLE_ON_INIT BIT(0)
struct div4_clk {
const char *name;
unsigned int reg;
unsigned int shift;
};
static struct div4_clk div4_clks[] = {
{ "i", CPG_FRQCRA, 20 },
{ "m3", CPG_FRQCRA, 12 },
{ "b", CPG_FRQCRA, 8 },
{ "m1", CPG_FRQCRA, 4 },
{ "m2", CPG_FRQCRA, 0 },
{ "zx", CPG_FRQCRB, 12 },
{ "zs", CPG_FRQCRB, 8 },
{ "hp", CPG_FRQCRB, 4 },
{ NULL, 0, 0 },
};
static const struct clk_div_table div4_div_table[] = {
{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
{ 6, 16 }, { 7, 18 }, { 8, 24 }, { 10, 36 }, { 11, 48 },
{ 12, 10 }, { 0, 0 }
};
static struct clk * __init
r8a73a4_cpg_register_clock(struct device_node *np, struct r8a73a4_cpg *cpg,
const char *name)
{
const struct clk_div_table *table = NULL;
const char *parent_name;
unsigned int shift, reg;
unsigned int mult = 1;
unsigned int div = 1;
if (!strcmp(name, "main")) {
u32 ckscr = readl(cpg->reg + CPG_CKSCR);
switch ((ckscr >> 28) & 3) {
case 0: /* extal1 */
parent_name = of_clk_get_parent_name(np, 0);
break;
case 1: /* extal1 / 2 */
parent_name = of_clk_get_parent_name(np, 0);
div = 2;
break;
case 2: /* extal2 */
parent_name = of_clk_get_parent_name(np, 1);
break;
case 3: /* extal2 / 2 */
parent_name = of_clk_get_parent_name(np, 1);
div = 2;
break;
}
} else if (!strcmp(name, "pll0")) {
/* PLL0/1 are configurable multiplier clocks. Register them as
* fixed factor clocks for now as there's no generic multiplier
* clock implementation and we currently have no need to change
* the multiplier value.
*/
u32 value = readl(cpg->reg + CPG_PLL0CR);
parent_name = "main";
mult = ((value >> 24) & 0x7f) + 1;
if (value & BIT(20))
div = 2;
} else if (!strcmp(name, "pll1")) {
u32 value = readl(cpg->reg + CPG_PLL1CR);
parent_name = "main";
/* XXX: enable bit? */
mult = ((value >> 24) & 0x7f) + 1;
if (value & BIT(7))
div = 2;
} else if (!strncmp(name, "pll2", 4)) {
u32 value, cr;
switch (name[4]) {
case 0:
cr = CPG_PLL2CR;
break;
case 's':
cr = CPG_PLL2SCR;
break;
case 'h':
cr = CPG_PLL2HCR;
break;
default:
return ERR_PTR(-EINVAL);
}
value = readl(cpg->reg + cr);
switch ((value >> 5) & 7) {
case 0:
parent_name = "main";
div = 2;
break;
case 1:
parent_name = "extal2";
div = 2;
break;
case 3:
parent_name = "extal2";
div = 4;
break;
case 4:
parent_name = "main";
break;
case 5:
parent_name = "extal2";
break;
default:
pr_warn("%s: unexpected parent of %s\n", __func__,
name);
return ERR_PTR(-EINVAL);
}
/* XXX: enable bit? */
mult = ((value >> 24) & 0x7f) + 1;
} else if (!strcmp(name, "z") || !strcmp(name, "z2")) {
u32 shift = 8;
parent_name = "pll0";
if (name[1] == '2') {
div = 2;
shift = 0;
}
div *= 32;
mult = 0x20 - ((readl(cpg->reg + CPG_FRQCRC) >> shift) & 0x1f);
} else {
struct div4_clk *c;
for (c = div4_clks; c->name; c++) {
if (!strcmp(name, c->name))
break;
}
if (!c->name)
return ERR_PTR(-EINVAL);
parent_name = "pll1";
table = div4_div_table;
reg = c->reg;
shift = c->shift;
}
if (!table) {
return clk_register_fixed_factor(NULL, name, parent_name, 0,
mult, div);
} else {
return clk_register_divider_table(NULL, name, parent_name, 0,
cpg->reg + reg, shift, 4, 0,
table, &cpg->lock);
}
}
static void __init r8a73a4_cpg_clocks_init(struct device_node *np)
{
struct r8a73a4_cpg *cpg;
struct clk **clks;
unsigned int i;
int num_clks;
num_clks = of_property_count_strings(np, "clock-output-names");
if (num_clks < 0) {
pr_err("%s: failed to count clocks\n", __func__);
return;
}
cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
if (cpg == NULL || clks == NULL) {
/* We're leaking memory on purpose, there's no point in cleaning
* up as the system won't boot anyway.
*/
return;
}
spin_lock_init(&cpg->lock);
cpg->data.clks = clks;
cpg->data.clk_num = num_clks;
cpg->reg = of_iomap(np, 0);
if (WARN_ON(cpg->reg == NULL))
return;
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 = r8a73a4_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(r8a73a4_cpg_clks, "renesas,r8a73a4-cpg-clocks",
r8a73a4_cpg_clocks_init);