clk: sunxi: Add a driver for the PLL2

The PLL2 on the A10 and later SoCs is the clock used for all the audio
related operations.

This clock has a somewhat complex output tree, with three outputs (2X, 4X
and 8X) with a fixed divider from the base clock, and an output (1X) with a
post divider.

However, we can simplify things since the 1X divider can be fixed, and we
end up by having a base clock not exposed to any device (or at least
directly, since the 4X output doesn't have any divider), and 4 fixed
divider clocks that will be exposed.

This clock seems to have been introduced, at least in this form, in the
revision B of the A10, but we don't have any information on the clock used
on the revision A.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
This commit is contained in:
Maxime Ripard 2014-07-18 15:48:35 -03:00
parent f2e0a53271
commit 460d0d4448
3 changed files with 242 additions and 0 deletions

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@ -4,6 +4,7 @@
obj-y += clk-sunxi.o clk-factors.o
obj-y += clk-a10-hosc.o
obj-y += clk-a10-pll2.o
obj-y += clk-a20-gmac.o
obj-y += clk-mod0.o
obj-y += clk-simple-gates.o

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@ -0,0 +1,188 @@
/*
* Copyright 2013 Emilio López
* Emilio López <emilio@elopez.com.ar>
*
* Copyright 2015 Maxime Ripard
* Maxime Ripard <maxime.ripard@free-electrons.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*/
#include <linux/clk-provider.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <dt-bindings/clock/sun4i-a10-pll2.h>
#define SUN4I_PLL2_ENABLE 31
#define SUN4I_PLL2_PRE_DIV_SHIFT 0
#define SUN4I_PLL2_PRE_DIV_WIDTH 5
#define SUN4I_PLL2_PRE_DIV_MASK GENMASK(SUN4I_PLL2_PRE_DIV_WIDTH - 1, 0)
#define SUN4I_PLL2_N_SHIFT 8
#define SUN4I_PLL2_N_WIDTH 7
#define SUN4I_PLL2_N_MASK GENMASK(SUN4I_PLL2_N_WIDTH - 1, 0)
#define SUN4I_PLL2_POST_DIV_SHIFT 26
#define SUN4I_PLL2_POST_DIV_WIDTH 4
#define SUN4I_PLL2_POST_DIV_MASK GENMASK(SUN4I_PLL2_POST_DIV_WIDTH - 1, 0)
#define SUN4I_PLL2_POST_DIV_VALUE 4
#define SUN4I_PLL2_OUTPUTS 4
static DEFINE_SPINLOCK(sun4i_a10_pll2_lock);
static void __init sun4i_pll2_setup(struct device_node *node)
{
const char *clk_name = node->name, *parent;
struct clk **clks, *base_clk, *prediv_clk;
struct clk_onecell_data *clk_data;
struct clk_multiplier *mult;
struct clk_gate *gate;
void __iomem *reg;
u32 val;
reg = of_io_request_and_map(node, 0, of_node_full_name(node));
if (IS_ERR(reg))
return;
clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
if (!clk_data)
goto err_unmap;
clks = kcalloc(SUN4I_PLL2_OUTPUTS, sizeof(struct clk *), GFP_KERNEL);
if (!clks)
goto err_free_data;
parent = of_clk_get_parent_name(node, 0);
prediv_clk = clk_register_divider(NULL, "pll2-prediv",
parent, 0, reg,
SUN4I_PLL2_PRE_DIV_SHIFT,
SUN4I_PLL2_PRE_DIV_WIDTH,
CLK_DIVIDER_ONE_BASED |
CLK_DIVIDER_ALLOW_ZERO,
&sun4i_a10_pll2_lock);
if (!prediv_clk) {
pr_err("Couldn't register the prediv clock\n");
goto err_free_array;
}
/* Setup the gate part of the PLL2 */
gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL);
if (!gate)
goto err_unregister_prediv;
gate->reg = reg;
gate->bit_idx = SUN4I_PLL2_ENABLE;
gate->lock = &sun4i_a10_pll2_lock;
/* Setup the multiplier part of the PLL2 */
mult = kzalloc(sizeof(struct clk_multiplier), GFP_KERNEL);
if (!mult)
goto err_free_gate;
mult->reg = reg;
mult->shift = SUN4I_PLL2_N_SHIFT;
mult->width = 7;
mult->flags = CLK_MULTIPLIER_ZERO_BYPASS |
CLK_MULTIPLIER_ROUND_CLOSEST;
mult->lock = &sun4i_a10_pll2_lock;
parent = __clk_get_name(prediv_clk);
base_clk = clk_register_composite(NULL, "pll2-base",
&parent, 1,
NULL, NULL,
&mult->hw, &clk_multiplier_ops,
&gate->hw, &clk_gate_ops,
CLK_SET_RATE_PARENT);
if (!base_clk) {
pr_err("Couldn't register the base multiplier clock\n");
goto err_free_multiplier;
}
parent = __clk_get_name(base_clk);
/*
* PLL2-1x
*
* This is supposed to have a post divider, but we won't need
* to use it, we just need to initialise it to 4, and use a
* fixed divider.
*/
val = readl(reg);
val &= ~(SUN4I_PLL2_POST_DIV_MASK << SUN4I_PLL2_POST_DIV_SHIFT);
val |= SUN4I_PLL2_POST_DIV_VALUE << SUN4I_PLL2_POST_DIV_SHIFT;
writel(val, reg);
of_property_read_string_index(node, "clock-output-names",
SUN4I_A10_PLL2_1X, &clk_name);
clks[SUN4I_A10_PLL2_1X] = clk_register_fixed_factor(NULL, clk_name,
parent,
CLK_SET_RATE_PARENT,
1,
SUN4I_PLL2_POST_DIV_VALUE);
WARN_ON(IS_ERR(clks[SUN4I_A10_PLL2_1X]));
/*
* PLL2-2x
*
* This clock doesn't use the post divider, and really is just
* a fixed divider from the PLL2 base clock.
*/
of_property_read_string_index(node, "clock-output-names",
SUN4I_A10_PLL2_2X, &clk_name);
clks[SUN4I_A10_PLL2_2X] = clk_register_fixed_factor(NULL, clk_name,
parent,
CLK_SET_RATE_PARENT,
1, 2);
WARN_ON(IS_ERR(clks[SUN4I_A10_PLL2_2X]));
/* PLL2-4x */
of_property_read_string_index(node, "clock-output-names",
SUN4I_A10_PLL2_4X, &clk_name);
clks[SUN4I_A10_PLL2_4X] = clk_register_fixed_factor(NULL, clk_name,
parent,
CLK_SET_RATE_PARENT,
1, 1);
WARN_ON(IS_ERR(clks[SUN4I_A10_PLL2_4X]));
/* PLL2-8x */
of_property_read_string_index(node, "clock-output-names",
SUN4I_A10_PLL2_8X, &clk_name);
clks[SUN4I_A10_PLL2_8X] = clk_register_fixed_factor(NULL, clk_name,
parent,
CLK_SET_RATE_PARENT,
2, 1);
WARN_ON(IS_ERR(clks[SUN4I_A10_PLL2_8X]));
clk_data->clks = clks;
clk_data->clk_num = SUN4I_PLL2_OUTPUTS;
of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
return;
err_free_multiplier:
kfree(mult);
err_free_gate:
kfree(gate);
err_unregister_prediv:
clk_unregister_divider(prediv_clk);
err_free_array:
kfree(clks);
err_free_data:
kfree(clk_data);
err_unmap:
iounmap(reg);
}
CLK_OF_DECLARE(sun4i_pll2, "allwinner,sun4i-a10-pll2-clk", sun4i_pll2_setup);

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@ -0,0 +1,53 @@
/*
* Copyright 2015 Maxime Ripard
*
* Maxime Ripard <maxime.ripard@free-electrons.com>
*
* This file is dual-licensed: you can use it either under the terms
* of the GPL or the X11 license, at your option. Note that this dual
* licensing only applies to this file, and not this project as a
* whole.
*
* a) This file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This file 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.
*
* Or, alternatively,
*
* b) Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef __DT_BINDINGS_CLOCK_SUN4I_A10_PLL2_H_
#define __DT_BINDINGS_CLOCK_SUN4I_A10_PLL2_H_
#define SUN4I_A10_PLL2_1X 0
#define SUN4I_A10_PLL2_2X 1
#define SUN4I_A10_PLL2_4X 2
#define SUN4I_A10_PLL2_8X 3
#endif /* __DT_BINDINGS_CLOCK_SUN4I_A10_PLL2_H_ */