diff options
Diffstat (limited to 'drivers/clk/versatile')
| -rw-r--r-- | drivers/clk/versatile/Makefile | 2 | ||||
| -rw-r--r-- | drivers/clk/versatile/clk-sp810.c | 188 | ||||
| -rw-r--r-- | drivers/clk/versatile/clk-vexpress.c | 49 | 
3 files changed, 189 insertions, 50 deletions
diff --git a/drivers/clk/versatile/Makefile b/drivers/clk/versatile/Makefile index ec3b88fe3e6..c16ca787170 100644 --- a/drivers/clk/versatile/Makefile +++ b/drivers/clk/versatile/Makefile @@ -3,5 +3,5 @@ obj-$(CONFIG_ICST)		+= clk-icst.o  obj-$(CONFIG_ARCH_INTEGRATOR)	+= clk-integrator.o  obj-$(CONFIG_INTEGRATOR_IMPD1)	+= clk-impd1.o  obj-$(CONFIG_ARCH_REALVIEW)	+= clk-realview.o -obj-$(CONFIG_ARCH_VEXPRESS)	+= clk-vexpress.o +obj-$(CONFIG_ARCH_VEXPRESS)	+= clk-vexpress.o clk-sp810.o  obj-$(CONFIG_VEXPRESS_CONFIG)	+= clk-vexpress-osc.o diff --git a/drivers/clk/versatile/clk-sp810.c b/drivers/clk/versatile/clk-sp810.c new file mode 100644 index 00000000000..bf9b15a585e --- /dev/null +++ b/drivers/clk/versatile/clk-sp810.c @@ -0,0 +1,188 @@ +/* + * 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/clkdev.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; +	int refclk_index, timclk_index; +	void __iomem *base; +	spinlock_t lock; +	struct clk_sp810_timerclken timerclken[4]; +	struct clk *refclk; +	struct clk *timclk; +}; + +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; +} + +/* + * FIXME - setting the parent every time .prepare is invoked is inefficient. + * This is better handled by a dedicated clock tree configuration mechanism at + * init-time.  Revisit this later when such a mechanism exists + */ +static int clk_sp810_timerclken_prepare(struct clk_hw *hw) +{ +	struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw); +	struct clk_sp810 *sp810 = timerclken->sp810; +	struct clk *old_parent = __clk_get_parent(hw->clk); +	struct clk *new_parent; + +	if (!sp810->refclk) +		sp810->refclk = of_clk_get(sp810->node, sp810->refclk_index); + +	if (!sp810->timclk) +		sp810->timclk = of_clk_get(sp810->node, sp810->timclk_index); + +	if (WARN_ON(IS_ERR(sp810->refclk) || IS_ERR(sp810->timclk))) +		return -ENOENT; + +	/* Select fastest parent */ +	if (clk_get_rate(sp810->refclk) > clk_get_rate(sp810->timclk)) +		new_parent = sp810->refclk; +	else +		new_parent = sp810->timclk; + +	/* Switch the parent if necessary */ +	if (old_parent != new_parent) { +		clk_prepare(new_parent); +		clk_set_parent(hw->clk, new_parent); +		clk_unprepare(old_parent); +	} + +	return 0; +} + +static void clk_sp810_timerclken_unprepare(struct clk_hw *hw) +{ +	struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw); +	struct clk_sp810 *sp810 = timerclken->sp810; + +	clk_put(sp810->timclk); +	clk_put(sp810->refclk); +} + +static const struct clk_ops clk_sp810_timerclken_ops = { +	.prepare = clk_sp810_timerclken_prepare, +	.unprepare = clk_sp810_timerclken_unprepare, +	.get_parent = clk_sp810_timerclken_get_parent, +	.set_parent = clk_sp810_timerclken_set_parent, +}; + +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; +} + +void __init clk_sp810_of_setup(struct device_node *node) +{ +	struct clk_sp810 *sp810 = kzalloc(sizeof(*sp810), GFP_KERNEL); +	const char *parent_names[2]; +	char name[12]; +	struct clk_init_data init; +	int i; + +	if (!sp810) { +		pr_err("Failed to allocate memory for SP810!\n"); +		return; +	} + +	sp810->refclk_index = of_property_match_string(node, "clock-names", +			"refclk"); +	parent_names[0] = of_clk_get_parent_name(node, sp810->refclk_index); + +	sp810->timclk_index = of_property_match_string(node, "clock-names", +			"timclk"); +	parent_names[1] = of_clk_get_parent_name(node, sp810->timclk_index); + +	if (parent_names[0] <= 0 || parent_names[1] <= 0) { +		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 = ARRAY_SIZE(parent_names); + +	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; + +		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); diff --git a/drivers/clk/versatile/clk-vexpress.c b/drivers/clk/versatile/clk-vexpress.c index 82b45aad8cc..a4a728d0509 100644 --- a/drivers/clk/versatile/clk-vexpress.c +++ b/drivers/clk/versatile/clk-vexpress.c @@ -15,8 +15,6 @@  #include <linux/clkdev.h>  #include <linux/clk-provider.h>  #include <linux/err.h> -#include <linux/of.h> -#include <linux/of_address.h>  #include <linux/vexpress.h>  static struct clk *vexpress_sp810_timerclken[4]; @@ -86,50 +84,3 @@ void __init vexpress_clk_init(void __iomem *sp810_base)  	WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],  				"v2m-timer1", "sp804"));  } - -#if defined(CONFIG_OF) - -struct clk *vexpress_sp810_of_get(struct of_phandle_args *clkspec, void *data) -{ -	if (WARN_ON(clkspec->args_count != 1 || clkspec->args[0] > -			ARRAY_SIZE(vexpress_sp810_timerclken))) -		return NULL; - -	return vexpress_sp810_timerclken[clkspec->args[0]]; -} - -void __init vexpress_clk_of_init(void) -{ -	struct device_node *node; -	struct clk *clk; -	struct clk *refclk, *timclk; - -	of_clk_init(NULL); - -	node = of_find_compatible_node(NULL, NULL, "arm,sp810"); -	vexpress_sp810_init(of_iomap(node, 0)); -	of_clk_add_provider(node, vexpress_sp810_of_get, NULL); - -	/* Select "better" (faster) parent for SP804 timers */ -	refclk = of_clk_get_by_name(node, "refclk"); -	timclk = of_clk_get_by_name(node, "timclk"); -	if (!WARN_ON(IS_ERR(refclk) || IS_ERR(timclk))) { -		int i = 0; - -		if (clk_get_rate(refclk) > clk_get_rate(timclk)) -			clk = refclk; -		else -			clk = timclk; - -		for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++) -			WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i], -					clk)); -	} - -	WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0], -				"v2m-timer0", "sp804")); -	WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1], -				"v2m-timer1", "sp804")); -} - -#endif  |