[v2,01/27] clk: mvebu: Add Core Divider clock

This commit introduces a new group of clocks present in Armada 370/XP
SoCs (called "Core Divider" clocks) and add a provider for them.
The only clock supported for now is the NAND clock (ndclk), but the
infrastructure to add the rest is already set.

Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
---
 drivers/clk/mvebu/Kconfig       |   5 +
 drivers/clk/mvebu/Makefile      |   1 +
 drivers/clk/mvebu/clk-corediv.c | 223 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 229 insertions(+)
 create mode 100644 drivers/clk/mvebu/clk-corediv.c

Ezequiel,

MikeT took this the other day.

As such, I've taken in patches 2-4 inclusive into mvebu/dt.  That should
be the last items for this window.

Please drop them from your series next time around.

thx,

Jason.

On Fri, Oct 18, 2013 at 08:02:28PM -0300, Ezequiel Garcia wrote:
> This commit introduces a new group of clocks present in Armada 370/XP
> SoCs (called "Core Divider" clocks) and add a provider for them.
> The only clock supported for now is the NAND clock (ndclk), but the
> infrastructure to add the rest is already set.
> 
> Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> Acked-by: Jason Cooper <jason@lakedaemon.net>
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> ---
>  drivers/clk/mvebu/Kconfig       |   5 +
>  drivers/clk/mvebu/Makefile      |   1 +
>  drivers/clk/mvebu/clk-corediv.c | 223 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 229 insertions(+)
>  create mode 100644 drivers/clk/mvebu/clk-corediv.c
> 
> diff --git a/drivers/clk/mvebu/Kconfig b/drivers/clk/mvebu/Kconfig
> index 0b0f3e7..c339b82 100644
> --- a/drivers/clk/mvebu/Kconfig
> +++ b/drivers/clk/mvebu/Kconfig
> @@ -4,15 +4,20 @@ config MVEBU_CLK_COMMON
>  config MVEBU_CLK_CPU
>  	bool
>  
> +config MVEBU_CLK_COREDIV
> +	bool
> +
>  config ARMADA_370_CLK
>  	bool
>  	select MVEBU_CLK_COMMON
>  	select MVEBU_CLK_CPU
> +	select MVEBU_CLK_COREDIV
>  
>  config ARMADA_XP_CLK
>  	bool
>  	select MVEBU_CLK_COMMON
>  	select MVEBU_CLK_CPU
> +	select MVEBU_CLK_COREDIV
>  
>  config DOVE_CLK
>  	bool
> diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
> index 1c7e70c..21bbfb4 100644
> --- a/drivers/clk/mvebu/Makefile
> +++ b/drivers/clk/mvebu/Makefile
> @@ -1,5 +1,6 @@
>  obj-$(CONFIG_MVEBU_CLK_COMMON)	+= common.o
>  obj-$(CONFIG_MVEBU_CLK_CPU) 	+= clk-cpu.o
> +obj-$(CONFIG_MVEBU_CLK_COREDIV)	+= clk-corediv.o
>  
>  obj-$(CONFIG_ARMADA_370_CLK)	+= armada-370.o
>  obj-$(CONFIG_ARMADA_XP_CLK)	+= armada-xp.o
> diff --git a/drivers/clk/mvebu/clk-corediv.c b/drivers/clk/mvebu/clk-corediv.c
> new file mode 100644
> index 0000000..7162615
> --- /dev/null
> +++ b/drivers/clk/mvebu/clk-corediv.c
> @@ -0,0 +1,223 @@
> +/*
> + * MVEBU Core divider clock
> + *
> + * Copyright (C) 2013 Marvell
> + *
> + * Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> + *
> + * 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-provider.h>
> +#include <linux/of_address.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include "common.h"
> +
> +#define CORE_CLK_DIV_RATIO_MASK		0xff
> +#define CORE_CLK_DIV_RATIO_RELOAD	BIT(8)
> +#define CORE_CLK_DIV_ENABLE_OFFSET	24
> +#define CORE_CLK_DIV_RATIO_OFFSET	0x8
> +
> +struct clk_corediv_desc {
> +	unsigned int mask;
> +	unsigned int offset;
> +	unsigned int fieldbit;
> +};
> +
> +struct clk_corediv {
> +	struct clk_hw hw;
> +	void __iomem *reg;
> +	struct clk_corediv_desc desc;
> +	spinlock_t lock;
> +};
> +
> +static struct clk_onecell_data clk_data;
> +
> +static const struct clk_corediv_desc mvebu_corediv_desc[] __initconst = {
> +	{ .mask = 0x3f, .offset = 8, .fieldbit = 1 }, /* NAND clock */
> +};
> +
> +#define to_corediv_clk(p) container_of(p, struct clk_corediv, hw)
> +
> +static int clk_corediv_is_enabled(struct clk_hw *hwclk)
> +{
> +	struct clk_corediv *corediv = to_corediv_clk(hwclk);
> +	struct clk_corediv_desc *desc = &corediv->desc;
> +	u32 enable_mask = BIT(desc->fieldbit) << CORE_CLK_DIV_ENABLE_OFFSET;
> +
> +	return !!(readl(corediv->reg) & enable_mask);
> +}
> +
> +static int clk_corediv_enable(struct clk_hw *hwclk)
> +{
> +	struct clk_corediv *corediv = to_corediv_clk(hwclk);
> +	struct clk_corediv_desc *desc = &corediv->desc;
> +	unsigned long flags = 0;
> +	u32 reg;
> +
> +	spin_lock_irqsave(&corediv->lock, flags);
> +
> +	reg = readl(corediv->reg);
> +	reg |= (BIT(desc->fieldbit) << CORE_CLK_DIV_ENABLE_OFFSET);
> +	writel(reg, corediv->reg);
> +
> +	spin_unlock_irqrestore(&corediv->lock, flags);
> +
> +	return 0;
> +}
> +
> +static void clk_corediv_disable(struct clk_hw *hwclk)
> +{
> +	struct clk_corediv *corediv = to_corediv_clk(hwclk);
> +	struct clk_corediv_desc *desc = &corediv->desc;
> +	unsigned long flags = 0;
> +	u32 reg;
> +
> +	spin_lock_irqsave(&corediv->lock, flags);
> +
> +	reg = readl(corediv->reg);
> +	reg &= ~(BIT(desc->fieldbit) << CORE_CLK_DIV_ENABLE_OFFSET);
> +	writel(reg, corediv->reg);
> +
> +	spin_unlock_irqrestore(&corediv->lock, flags);
> +}
> +
> +static unsigned long clk_corediv_recalc_rate(struct clk_hw *hwclk,
> +					 unsigned long parent_rate)
> +{
> +	struct clk_corediv *corediv = to_corediv_clk(hwclk);
> +	struct clk_corediv_desc *desc = &corediv->desc;
> +	u32 reg, div;
> +
> +	reg = readl(corediv->reg + CORE_CLK_DIV_RATIO_OFFSET);
> +	div = (reg >> desc->offset) & desc->mask;
> +	return parent_rate / div;
> +}
> +
> +static long clk_corediv_round_rate(struct clk_hw *hwclk, unsigned long rate,
> +			       unsigned long *parent_rate)
> +{
> +	/* Valid ratio are 1:4, 1:5, 1:6 and 1:8 */
> +	u32 div;
> +
> +	div = *parent_rate / rate;
> +	if (div < 4)
> +		div = 4;
> +	else if (div > 6)
> +		div = 8;
> +
> +	return *parent_rate / div;
> +}
> +
> +static int clk_corediv_set_rate(struct clk_hw *hwclk, unsigned long rate,
> +			    unsigned long parent_rate)
> +{
> +	struct clk_corediv *corediv = to_corediv_clk(hwclk);
> +	struct clk_corediv_desc *desc = &corediv->desc;
> +	unsigned long flags = 0;
> +	u32 reg, div;
> +
> +	div = parent_rate / rate;
> +
> +	spin_lock_irqsave(&corediv->lock, flags);
> +
> +	/* Write new divider to the divider ratio register */
> +	reg = readl(corediv->reg + CORE_CLK_DIV_RATIO_OFFSET);
> +	reg &= ~(desc->mask << desc->offset);
> +	reg |= (div & desc->mask) << desc->offset;
> +	writel(reg, corediv->reg + CORE_CLK_DIV_RATIO_OFFSET);
> +
> +	/* Set reload-force for this clock */
> +	reg = readl(corediv->reg) | BIT(desc->fieldbit);
> +	writel(reg, corediv->reg);
> +
> +	/* Now trigger the clock update */
> +	reg = readl(corediv->reg) | CORE_CLK_DIV_RATIO_RELOAD;
> +	writel(reg, corediv->reg);
> +
> +	/*
> +	 * Wait for clocks to settle down, and then clear all the
> +	 * ratios request and the reload request.
> +	 */
> +	udelay(1000);
> +	reg &= ~(CORE_CLK_DIV_RATIO_MASK | CORE_CLK_DIV_RATIO_RELOAD);
> +	writel(reg, corediv->reg);
> +	udelay(1000);
> +
> +	spin_unlock_irqrestore(&corediv->lock, flags);
> +
> +	return 0;
> +}
> +
> +static const struct clk_ops corediv_ops = {
> +	.enable = clk_corediv_enable,
> +	.disable = clk_corediv_disable,
> +	.is_enabled = clk_corediv_is_enabled,
> +	.recalc_rate = clk_corediv_recalc_rate,
> +	.round_rate = clk_corediv_round_rate,
> +	.set_rate = clk_corediv_set_rate,
> +};
> +
> +static void __init mvebu_corediv_clk_init(struct device_node *node)
> +{
> +	struct clk_init_data init;
> +	struct clk_corediv *corediv;
> +	struct clk **clks;
> +	void __iomem *base;
> +	const char *parent_name;
> +	const char *clk_name;
> +	int i;
> +
> +	base = of_iomap(node, 0);
> +	if (WARN_ON(!base))
> +		return;
> +
> +	parent_name = of_clk_get_parent_name(node, 0);
> +
> +	clk_data.clk_num = ARRAY_SIZE(mvebu_corediv_desc);
> +
> +	/* clks holds the clock array */
> +	clks = kcalloc(clk_data.clk_num, sizeof(struct clk *),
> +				GFP_KERNEL);
> +	if (WARN_ON(!clks))
> +		goto err_unmap;
> +	/* corediv holds the clock specific array */
> +	corediv = kcalloc(clk_data.clk_num, sizeof(struct clk_corediv),
> +				GFP_KERNEL);
> +	if (WARN_ON(!corediv))
> +		goto err_free_clks;
> +
> +	spin_lock_init(&corediv->lock);
> +
> +	for (i = 0; i < clk_data.clk_num; i++) {
> +		of_property_read_string_index(node, "clock-output-names",
> +					      i, &clk_name);
> +		init.num_parents = 1;
> +		init.parent_names = &parent_name;
> +		init.name = clk_name;
> +		init.ops = &corediv_ops;
> +		init.flags = 0;
> +
> +		corediv[i].desc = mvebu_corediv_desc[i];
> +		corediv[i].reg = base;
> +		corediv[i].hw.init = &init;
> +
> +		clks[i] = clk_register(NULL, &corediv[i].hw);
> +		WARN_ON(IS_ERR(clks[i]));
> +	}
> +
> +	clk_data.clks = clks;
> +	of_clk_add_provider(node, of_clk_src_onecell_get, &clk_data);
> +	return;
> +
> +err_free_clks:
> +	kfree(clks);
> +err_unmap:
> +	iounmap(base);
> +}
> +CLK_OF_DECLARE(mvebu_corediv_clk, "marvell,armada-370-corediv-clock",
> +	       mvebu_corediv_clk_init);
> -- 
> 1.8.1.5
> 
> 
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> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Jason,

On Wed, Oct 23, 2013 at 07:28:23AM -0400, Jason Cooper wrote:
> Ezequiel,
> 
> MikeT took this the other day.
> 
> As such, I've taken in patches 2-4 inclusive into mvebu/dt.  That should
> be the last items for this window.
> 

Just saw the pull... thanks a lot!