1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (C) 2016 Socionext Inc.
  4 *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
  5 */
  6
  7#include <linux/clk-provider.h>
  8#include <linux/device.h>
  9#include <linux/regmap.h>
 10
 11#include "clk-uniphier.h"
 12
 13#define UNIPHIER_CLK_CPUGEAR_STAT	0	/* status */
 14#define UNIPHIER_CLK_CPUGEAR_SET	4	/* set */
 15#define UNIPHIER_CLK_CPUGEAR_UPD	8	/* update */
 16#define   UNIPHIER_CLK_CPUGEAR_UPD_BIT	BIT(0)
 17
 18struct uniphier_clk_cpugear {
 19	struct clk_hw hw;
 20	struct regmap *regmap;
 21	unsigned int regbase;
 22	unsigned int mask;
 23};
 24
 25#define to_uniphier_clk_cpugear(_hw) \
 26			container_of(_hw, struct uniphier_clk_cpugear, hw)
 27
 28static int uniphier_clk_cpugear_set_parent(struct clk_hw *hw, u8 index)
 29{
 30	struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw);
 31	int ret;
 32	unsigned int val;
 33
 34	ret = regmap_write_bits(gear->regmap,
 35				gear->regbase + UNIPHIER_CLK_CPUGEAR_SET,
 36				gear->mask, index);
 37	if (ret)
 38		return ret;
 39
 40	ret = regmap_write_bits(gear->regmap,
 41				gear->regbase + UNIPHIER_CLK_CPUGEAR_UPD,
 42				UNIPHIER_CLK_CPUGEAR_UPD_BIT,
 43				UNIPHIER_CLK_CPUGEAR_UPD_BIT);
 44	if (ret)
 45		return ret;
 46
 47	return regmap_read_poll_timeout(gear->regmap,
 48				gear->regbase + UNIPHIER_CLK_CPUGEAR_UPD,
 49				val, !(val & UNIPHIER_CLK_CPUGEAR_UPD_BIT),
 50				0, 1);
 51}
 52
 53static u8 uniphier_clk_cpugear_get_parent(struct clk_hw *hw)
 54{
 55	struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw);
 56	int num_parents = clk_hw_get_num_parents(hw);
 57	int ret;
 58	unsigned int val;
 59
 60	ret = regmap_read(gear->regmap,
 61			  gear->regbase + UNIPHIER_CLK_CPUGEAR_STAT, &val);
 62	if (ret)
 63		return ret;
 64
 65	val &= gear->mask;
 66
 67	return val < num_parents ? val : -EINVAL;
 68}
 69
 70static const struct clk_ops uniphier_clk_cpugear_ops = {
 71	.determine_rate = __clk_mux_determine_rate,
 72	.set_parent = uniphier_clk_cpugear_set_parent,
 73	.get_parent = uniphier_clk_cpugear_get_parent,
 74};
 75
 76struct clk_hw *uniphier_clk_register_cpugear(struct device *dev,
 77					 struct regmap *regmap,
 78					 const char *name,
 79				const struct uniphier_clk_cpugear_data *data)
 80{
 81	struct uniphier_clk_cpugear *gear;
 82	struct clk_init_data init;
 83	int ret;
 84
 85	gear = devm_kzalloc(dev, sizeof(*gear), GFP_KERNEL);
 86	if (!gear)
 87		return ERR_PTR(-ENOMEM);
 88
 89	init.name = name;
 90	init.ops = &uniphier_clk_cpugear_ops;
 91	init.flags = CLK_SET_RATE_PARENT;
 92	init.parent_names = data->parent_names;
 93	init.num_parents = data->num_parents;
 94
 95	gear->regmap = regmap;
 96	gear->regbase = data->regbase;
 97	gear->mask = data->mask;
 98	gear->hw.init = &init;
 99
100	ret = devm_clk_hw_register(dev, &gear->hw);
101	if (ret)
102		return ERR_PTR(ret);
103
104	return &gear->hw;
105}