ARM: shmobile: r8a7778: common clock framework CPG driver

Driver for the r8a7778's clocks that depend on the mode bits.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Michael Turquette <mturquette@linaro.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
This commit is contained in:
Ulrich Hecht 2015-02-26 17:42:07 +01:00 committed by Simon Horman
parent a5dc23f689
commit 6232c51cb3
4 changed files with 170 additions and 0 deletions

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* Renesas R8A7778 Clock Pulse Generator (CPG)
The CPG generates core clocks for the R8A7778. It includes two PLLs and
several fixed ratio dividers
Required Properties:
- compatible: Must be "renesas,r8a7778-cpg-clocks"
- reg: Base address and length of the memory resource used by the CPG
- #clock-cells: Must be 1
- clock-output-names: The names of the clocks. Supported clocks are
"plla", "pllb", "b", "out", "p", "s", and "s1".
Example
-------
cpg_clocks: cpg_clocks@ffc80000 {
compatible = "renesas,r8a7778-cpg-clocks";
reg = <0xffc80000 0x80>;
#clock-cells = <1>;
clocks = <&extal_clk>;
clock-output-names = "plla", "pllb", "b",
"out", "p", "s", "s1";
};

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@ -2,6 +2,7 @@ obj-$(CONFIG_ARCH_EMEV2) += clk-emev2.o
obj-$(CONFIG_ARCH_R7S72100) += clk-rz.o
obj-$(CONFIG_ARCH_R8A73A4) += clk-r8a73a4.o
obj-$(CONFIG_ARCH_R8A7740) += clk-r8a7740.o
obj-$(CONFIG_ARCH_R8A7778) += clk-r8a7778.o
obj-$(CONFIG_ARCH_R8A7779) += clk-r8a7779.o
obj-$(CONFIG_ARCH_R8A7790) += clk-rcar-gen2.o
obj-$(CONFIG_ARCH_R8A7791) += clk-rcar-gen2.o

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/*
* r8a7778 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/clkdev.h>
#include <linux/clk/shmobile.h>
#include <linux/of_address.h>
struct r8a7778_cpg {
struct clk_onecell_data data;
spinlock_t lock;
void __iomem *reg;
};
/* PLL multipliers per bits 11, 12, and 18 of MODEMR */
struct {
unsigned long plla_mult;
unsigned long pllb_mult;
} r8a7778_rates[] __initdata = {
[0] = { 21, 21 },
[1] = { 24, 24 },
[2] = { 28, 28 },
[3] = { 32, 32 },
[5] = { 24, 21 },
[6] = { 28, 21 },
[7] = { 32, 24 },
};
/* Clock dividers per bits 1 and 2 of MODEMR */
struct {
const char *name;
unsigned int div[4];
} r8a7778_divs[6] __initdata = {
{ "b", { 12, 12, 16, 18 } },
{ "out", { 12, 12, 16, 18 } },
{ "p", { 16, 12, 16, 12 } },
{ "s", { 4, 3, 4, 3 } },
{ "s1", { 8, 6, 8, 6 } },
};
static u32 cpg_mode_rates __initdata;
static u32 cpg_mode_divs __initdata;
static struct clk * __init
r8a7778_cpg_register_clock(struct device_node *np, struct r8a7778_cpg *cpg,
const char *name)
{
if (!strcmp(name, "plla")) {
return clk_register_fixed_factor(NULL, "plla",
of_clk_get_parent_name(np, 0), 0,
r8a7778_rates[cpg_mode_rates].plla_mult, 1);
} else if (!strcmp(name, "pllb")) {
return clk_register_fixed_factor(NULL, "pllb",
of_clk_get_parent_name(np, 0), 0,
r8a7778_rates[cpg_mode_rates].pllb_mult, 1);
} else {
unsigned int i;
for (i = 0; i < ARRAY_SIZE(r8a7778_divs); i++) {
if (!strcmp(name, r8a7778_divs[i].name)) {
return clk_register_fixed_factor(NULL,
r8a7778_divs[i].name,
"plla", 0, 1,
r8a7778_divs[i].div[cpg_mode_divs]);
}
}
}
return ERR_PTR(-EINVAL);
}
static void __init r8a7778_cpg_clocks_init(struct device_node *np)
{
struct r8a7778_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 = r8a7778_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(r8a7778_cpg_clks, "renesas,r8a7778-cpg-clocks",
r8a7778_cpg_clocks_init);
void __init r8a7778_clocks_init(u32 mode)
{
BUG_ON(!(mode & BIT(19)));
cpg_mode_rates = (!!(mode & BIT(18)) << 2) |
(!!(mode & BIT(12)) << 1) |
(!!(mode & BIT(11)));
cpg_mode_divs = (!!(mode & BIT(2)) << 1) |
(!!(mode & BIT(1)));
of_clk_init(NULL);
}

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@ -16,6 +16,7 @@
#include <linux/types.h>
void r8a7778_clocks_init(u32 mode);
void r8a7779_clocks_init(u32 mode);
void rcar_gen2_clocks_init(u32 mode);