alistair23-linux/drivers/clk/versatile/clk-sp810.c
Stephen Boyd 62f4771198 clk: versatile: Switch to assigned clock parents
We're removing struct clk from the clk provider API. This code is
calling the consumer APIs to change the parent to a 1 MHz fixed
rate clock for each of the clocks that the driver provides. Move
to using the assigned-clock-parents DT property for this instead.
Because this is an ABI break, detect if the property is missing
and fall back to setting the parent explicitly before the clocks
are registered.

Acked-by: Pawel Moll <pawel.moll@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:48:59 -07:00

144 lines
3.8 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright (C) 2013 ARM Limited
*/
#include <linux/amba/sp810.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_address.h>
#define to_clk_sp810_timerclken(_hw) \
container_of(_hw, struct clk_sp810_timerclken, hw)
struct clk_sp810;
struct clk_sp810_timerclken {
struct clk_hw hw;
struct clk *clk;
struct clk_sp810 *sp810;
int channel;
};
struct clk_sp810 {
struct device_node *node;
void __iomem *base;
spinlock_t lock;
struct clk_sp810_timerclken timerclken[4];
};
static u8 clk_sp810_timerclken_get_parent(struct clk_hw *hw)
{
struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw);
u32 val = readl(timerclken->sp810->base + SCCTRL);
return !!(val & (1 << SCCTRL_TIMERENnSEL_SHIFT(timerclken->channel)));
}
static int clk_sp810_timerclken_set_parent(struct clk_hw *hw, u8 index)
{
struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw);
struct clk_sp810 *sp810 = timerclken->sp810;
u32 val, shift = SCCTRL_TIMERENnSEL_SHIFT(timerclken->channel);
unsigned long flags = 0;
if (WARN_ON(index > 1))
return -EINVAL;
spin_lock_irqsave(&sp810->lock, flags);
val = readl(sp810->base + SCCTRL);
val &= ~(1 << shift);
val |= index << shift;
writel(val, sp810->base + SCCTRL);
spin_unlock_irqrestore(&sp810->lock, flags);
return 0;
}
static const struct clk_ops clk_sp810_timerclken_ops = {
.get_parent = clk_sp810_timerclken_get_parent,
.set_parent = clk_sp810_timerclken_set_parent,
};
static struct clk *clk_sp810_timerclken_of_get(struct of_phandle_args *clkspec,
void *data)
{
struct clk_sp810 *sp810 = data;
if (WARN_ON(clkspec->args_count != 1 ||
clkspec->args[0] >= ARRAY_SIZE(sp810->timerclken)))
return NULL;
return sp810->timerclken[clkspec->args[0]].clk;
}
static void __init clk_sp810_of_setup(struct device_node *node)
{
struct clk_sp810 *sp810 = kzalloc(sizeof(*sp810), GFP_KERNEL);
const char *parent_names[2];
int num = ARRAY_SIZE(parent_names);
char name[12];
struct clk_init_data init;
int i;
bool deprecated;
if (!sp810) {
pr_err("Failed to allocate memory for SP810!\n");
return;
}
if (of_clk_parent_fill(node, parent_names, num) != num) {
pr_warn("Failed to obtain parent clocks for SP810!\n");
return;
}
sp810->node = node;
sp810->base = of_iomap(node, 0);
spin_lock_init(&sp810->lock);
init.name = name;
init.ops = &clk_sp810_timerclken_ops;
init.flags = CLK_IS_BASIC;
init.parent_names = parent_names;
init.num_parents = num;
deprecated = !of_find_property(node, "assigned-clock-parents", NULL);
for (i = 0; i < ARRAY_SIZE(sp810->timerclken); i++) {
snprintf(name, ARRAY_SIZE(name), "timerclken%d", i);
sp810->timerclken[i].sp810 = sp810;
sp810->timerclken[i].channel = i;
sp810->timerclken[i].hw.init = &init;
/*
* If DT isn't setting the parent, force it to be
* the 1 MHz clock without going through the framework.
* We do this before clk_register() so that it can determine
* the parent and setup the tree properly.
*/
if (deprecated)
init.ops->set_parent(&sp810->timerclken[i].hw, 1);
sp810->timerclken[i].clk = clk_register(NULL,
&sp810->timerclken[i].hw);
WARN_ON(IS_ERR(sp810->timerclken[i].clk));
}
of_clk_add_provider(node, clk_sp810_timerclken_of_get, sp810);
}
CLK_OF_DECLARE(sp810, "arm,sp810", clk_sp810_of_setup);