Commit 1ec7032a authored by Thierry Reding's avatar Thierry Reding
Browse files

clk: tegra: Add fixed factor peripheral clock type 



Some of the peripheral clocks on Tegra are derived from one of the top-
level PLLs with a fixed factor. Support these clocks by implementing the
->enable() and ->disable() callbacks using the peripheral clock register
banks and the ->recalc_rate() by dividing the parent rate by the fixed
factor.

Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent 07314fc1

drivers/clk/tegra/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ obj-y += clk-audio-sync.o 
obj-y					+= clk-dfll.o

obj-y					+= clk-divider.o

obj-y					+= clk-periph.o

obj-y					+= clk-periph-fixed.o

obj-y					+= clk-periph-gate.o

obj-y					+= clk-pll.o

obj-y					+= clk-pll-out.o

drivers/clk/tegra/clk-periph-fixed.c

0 → 100644
+120 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2015, NVIDIA CORPORATION.  All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope 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.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#include <linux/clk-provider.h>



#include "clk.h"



static inline struct tegra_clk_periph_fixed *

to_tegra_clk_periph_fixed(struct clk_hw *hw)

{

	return container_of(hw, struct tegra_clk_periph_fixed, hw);

}



static int tegra_clk_periph_fixed_is_enabled(struct clk_hw *hw)

{

	struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);

	u32 mask = 1 << (fixed->num % 32), value;



	value = readl(fixed->base + fixed->regs->enb_reg);

	if (value & mask) {

		value = readl(fixed->base + fixed->regs->rst_reg);

		if ((value & mask) == 0)

			return 1;

	}



	return 0;

}



static int tegra_clk_periph_fixed_enable(struct clk_hw *hw)

{

	struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);

	u32 mask = 1 << (fixed->num % 32);



	writel(mask, fixed->base + fixed->regs->enb_set_reg);



	return 0;

}



static void tegra_clk_periph_fixed_disable(struct clk_hw *hw)

{

	struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);

	u32 mask = 1 << (fixed->num % 32);



	writel(mask, fixed->base + fixed->regs->enb_clr_reg);

}



static unsigned long

tegra_clk_periph_fixed_recalc_rate(struct clk_hw *hw,

				   unsigned long parent_rate)

{

	struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);

	unsigned long long rate;



	rate = (unsigned long long)parent_rate * fixed->mul;

	do_div(rate, fixed->div);



	return (unsigned long)rate;

}



static const struct clk_ops tegra_clk_periph_fixed_ops = {

	.is_enabled = tegra_clk_periph_fixed_is_enabled,

	.enable = tegra_clk_periph_fixed_enable,

	.disable = tegra_clk_periph_fixed_disable,

	.recalc_rate = tegra_clk_periph_fixed_recalc_rate,

};



struct clk *tegra_clk_register_periph_fixed(const char *name,

					    const char *parent,

					    unsigned long flags,

					    void __iomem *base,

					    unsigned int mul,

					    unsigned int div,

					    unsigned int num)

{

	const struct tegra_clk_periph_regs *regs;

	struct tegra_clk_periph_fixed *fixed;

	struct clk_init_data init;

	struct clk *clk;



	regs = get_reg_bank(num);

	if (!regs)

		return ERR_PTR(-EINVAL);



	fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);

	if (!fixed)

		return ERR_PTR(-ENOMEM);



	init.name = name;

	init.flags = flags;

	init.parent_names = parent ? &parent : NULL;

	init.num_parents = parent ? 1 : 0;

	init.ops = &tegra_clk_periph_fixed_ops;



	fixed->base = base;

	fixed->regs = regs;

	fixed->mul = mul;

	fixed->div = div;

	fixed->num = num;



	fixed->hw.init = &init;



	clk = clk_register(NULL, &fixed->hw);

	if (IS_ERR(clk))

		kfree(fixed);



	return clk;

}

drivers/clk/tegra/clk.h

+17 −0
Original line number Diff line number Diff line
@@ -516,6 +516,23 @@ struct clk *tegra_clk_register_periph_gate(const char *name, 
		const char *parent_name, u8 gate_flags, void __iomem *clk_base,

		unsigned long flags, int clk_num, int *enable_refcnt);



struct tegra_clk_periph_fixed {

	struct clk_hw hw;

	void __iomem *base;

	const struct tegra_clk_periph_regs *regs;

	unsigned int mul;

	unsigned int div;

	unsigned int num;

};



struct clk *tegra_clk_register_periph_fixed(const char *name,

					    const char *parent,

					    unsigned long flags,

					    void __iomem *base,

					    unsigned int mul,

					    unsigned int div,

					    unsigned int num);



/**

 * struct clk-periph - peripheral clock

 *