linux/drivers/clk/shmobile/clk-r8a7779.c
Simon Horman 7b42a997bf clk: shmobile: r8a7779: Add clocks support
The R8A7779 SoC has several clocks that are too custom to be supported in a
generic driver. Those clocks are all fixed rate clocks with multiplier and
divisor set according to boot mode configuration.

Based on work for R-Car Gen2 SoCs by Laurent Pinchart.

Cc: devicetree@vger.kernel.org
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-05-12 23:07:40 -07:00

181 lines
4.5 KiB
C

/*
* r8a7779 Core CPG Clocks
*
* Copyright (C) 2013, 2014 Horms Solutions Ltd.
*
* Contact: Simon Horman <horms@verge.net.au>
*
* 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/init.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/spinlock.h>
#include <dt-bindings/clock/r8a7779-clock.h>
#define CPG_NUM_CLOCKS (R8A7779_CLK_OUT + 1)
struct r8a7779_cpg {
struct clk_onecell_data data;
spinlock_t lock;
void __iomem *reg;
};
/* -----------------------------------------------------------------------------
* CPG Clock Data
*/
/*
* MD1 = 1 MD1 = 0
* (PLLA = 1500) (PLLA = 1600)
* (MHz) (MHz)
*------------------------------------------------+--------------------
* clkz 1000 (2/3) 800 (1/2)
* clkzs 250 (1/6) 200 (1/8)
* clki 750 (1/2) 800 (1/2)
* clks 250 (1/6) 200 (1/8)
* clks1 125 (1/12) 100 (1/16)
* clks3 187.5 (1/8) 200 (1/8)
* clks4 93.7 (1/16) 100 (1/16)
* clkp 62.5 (1/24) 50 (1/32)
* clkg 62.5 (1/24) 66.6 (1/24)
* clkb, CLKOUT
* (MD2 = 0) 62.5 (1/24) 66.6 (1/24)
* (MD2 = 1) 41.6 (1/36) 50 (1/32)
*/
#define CPG_CLK_CONFIG_INDEX(md) (((md) & (BIT(2)|BIT(1))) >> 1)
struct cpg_clk_config {
unsigned int z_mult;
unsigned int z_div;
unsigned int zs_and_s_div;
unsigned int s1_div;
unsigned int p_div;
unsigned int b_and_out_div;
};
static const struct cpg_clk_config cpg_clk_configs[4] __initconst = {
{ 1, 2, 8, 16, 32, 24 },
{ 2, 3, 6, 12, 24, 24 },
{ 1, 2, 8, 16, 32, 32 },
{ 2, 3, 6, 12, 24, 36 },
};
/*
* MD PLLA Ratio
* 12 11
*------------------------
* 0 0 x42
* 0 1 x48
* 1 0 x56
* 1 1 x64
*/
#define CPG_PLLA_MULT_INDEX(md) (((md) & (BIT(12)|BIT(11))) >> 11)
static const unsigned int cpg_plla_mult[4] __initconst = { 42, 48, 56, 64 };
/* -----------------------------------------------------------------------------
* Initialization
*/
static u32 cpg_mode __initdata;
static struct clk * __init
r8a7779_cpg_register_clock(struct device_node *np, struct r8a7779_cpg *cpg,
const struct cpg_clk_config *config,
unsigned int plla_mult, const char *name)
{
const char *parent_name = "plla";
unsigned int mult = 1;
unsigned int div = 1;
if (!strcmp(name, "plla")) {
parent_name = of_clk_get_parent_name(np, 0);
mult = plla_mult;
} else if (!strcmp(name, "z")) {
div = config->z_div;
mult = config->z_mult;
} else if (!strcmp(name, "zs") || !strcmp(name, "s")) {
div = config->zs_and_s_div;
} else if (!strcmp(name, "s1")) {
div = config->s1_div;
} else if (!strcmp(name, "p")) {
div = config->p_div;
} else if (!strcmp(name, "b") || !strcmp(name, "out")) {
div = config->b_and_out_div;
} else {
return ERR_PTR(-EINVAL);
}
return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, div);
}
static void __init r8a7779_cpg_clocks_init(struct device_node *np)
{
const struct cpg_clk_config *config;
struct r8a7779_cpg *cpg;
struct clk **clks;
unsigned int i, plla_mult;
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 = kzalloc(CPG_NUM_CLOCKS * 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;
config = &cpg_clk_configs[CPG_CLK_CONFIG_INDEX(cpg_mode)];
plla_mult = cpg_plla_mult[CPG_PLLA_MULT_INDEX(cpg_mode)];
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 = r8a7779_cpg_register_clock(np, cpg, config,
plla_mult, 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(r8a7779_cpg_clks, "renesas,r8a7779-cpg-clocks",
r8a7779_cpg_clocks_init);
void __init r8a7779_clocks_init(u32 mode)
{
cpg_mode = mode;
of_clk_init(NULL);
}