linux/drivers/clk/mvebu/common.c

170 lines
4.0 KiB
C

/*
* Marvell EBU SoC common clock handling
*
* Copyright (C) 2012 Marvell
*
* Gregory CLEMENT <gregory.clement@free-electrons.com>
* Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
* Andrew Lunn <andrew@lunn.ch>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include "common.h"
/*
* Core Clocks
*/
static struct clk_onecell_data clk_data;
void __init mvebu_coreclk_setup(struct device_node *np,
const struct coreclk_soc_desc *desc)
{
const char *tclk_name = "tclk";
const char *cpuclk_name = "cpuclk";
void __iomem *base;
unsigned long rate;
int n;
base = of_iomap(np, 0);
if (WARN_ON(!base))
return;
/* Allocate struct for TCLK, cpu clk, and core ratio clocks */
clk_data.clk_num = 2 + desc->num_ratios;
clk_data.clks = kzalloc(clk_data.clk_num * sizeof(struct clk *),
GFP_KERNEL);
if (WARN_ON(!clk_data.clks)) {
iounmap(base);
return;
}
/* Register TCLK */
of_property_read_string_index(np, "clock-output-names", 0,
&tclk_name);
rate = desc->get_tclk_freq(base);
clk_data.clks[0] = clk_register_fixed_rate(NULL, tclk_name, NULL,
CLK_IS_ROOT, rate);
WARN_ON(IS_ERR(clk_data.clks[0]));
/* Register CPU clock */
of_property_read_string_index(np, "clock-output-names", 1,
&cpuclk_name);
rate = desc->get_cpu_freq(base);
clk_data.clks[1] = clk_register_fixed_rate(NULL, cpuclk_name, NULL,
CLK_IS_ROOT, rate);
WARN_ON(IS_ERR(clk_data.clks[1]));
/* Register fixed-factor clocks derived from CPU clock */
for (n = 0; n < desc->num_ratios; n++) {
const char *rclk_name = desc->ratios[n].name;
int mult, div;
of_property_read_string_index(np, "clock-output-names",
2+n, &rclk_name);
desc->get_clk_ratio(base, desc->ratios[n].id, &mult, &div);
clk_data.clks[2+n] = clk_register_fixed_factor(NULL, rclk_name,
cpuclk_name, 0, mult, div);
WARN_ON(IS_ERR(clk_data.clks[2+n]));
};
/* SAR register isn't needed anymore */
iounmap(base);
of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
}
/*
* Clock Gating Control
*/
struct clk_gating_ctrl {
spinlock_t lock;
struct clk **gates;
int num_gates;
};
#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)
static struct clk *clk_gating_get_src(
struct of_phandle_args *clkspec, void *data)
{
struct clk_gating_ctrl *ctrl = (struct clk_gating_ctrl *)data;
int n;
if (clkspec->args_count < 1)
return ERR_PTR(-EINVAL);
for (n = 0; n < ctrl->num_gates; n++) {
struct clk_gate *gate =
to_clk_gate(__clk_get_hw(ctrl->gates[n]));
if (clkspec->args[0] == gate->bit_idx)
return ctrl->gates[n];
}
return ERR_PTR(-ENODEV);
}
void __init mvebu_clk_gating_setup(struct device_node *np,
const struct clk_gating_soc_desc *desc)
{
struct clk_gating_ctrl *ctrl;
struct clk *clk;
void __iomem *base;
const char *default_parent = NULL;
int n;
base = of_iomap(np, 0);
if (WARN_ON(!base))
return;
clk = of_clk_get(np, 0);
if (!IS_ERR(clk)) {
default_parent = __clk_get_name(clk);
clk_put(clk);
}
ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
if (WARN_ON(!ctrl))
goto ctrl_out;
spin_lock_init(&ctrl->lock);
/* Count, allocate, and register clock gates */
for (n = 0; desc[n].name;)
n++;
ctrl->num_gates = n;
ctrl->gates = kzalloc(ctrl->num_gates * sizeof(struct clk *),
GFP_KERNEL);
if (WARN_ON(!ctrl->gates))
goto gates_out;
for (n = 0; n < ctrl->num_gates; n++) {
const char *parent =
(desc[n].parent) ? desc[n].parent : default_parent;
ctrl->gates[n] = clk_register_gate(NULL, desc[n].name, parent,
desc[n].flags, base, desc[n].bit_idx,
0, &ctrl->lock);
WARN_ON(IS_ERR(ctrl->gates[n]));
}
of_clk_add_provider(np, clk_gating_get_src, ctrl);
return;
gates_out:
kfree(ctrl);
ctrl_out:
iounmap(base);
}