1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright 2014 Chen-Yu Tsai
  4 *
  5 * Chen-Yu Tsai <wens@csie.org>
  6 */
  7
  8#include <linux/clk.h>
  9#include <linux/clk-provider.h>
 10#include <linux/io.h>
 11#include <linux/slab.h>
 12#include <linux/spinlock.h>
 13#include <linux/of_address.h>
 14
 15#define SUN8I_MBUS_ENABLE	31
 16#define SUN8I_MBUS_MUX_SHIFT	24
 17#define SUN8I_MBUS_MUX_MASK	0x3
 18#define SUN8I_MBUS_DIV_SHIFT	0
 19#define SUN8I_MBUS_DIV_WIDTH	3
 20#define SUN8I_MBUS_MAX_PARENTS	4
 21
 22static DEFINE_SPINLOCK(sun8i_a23_mbus_lock);
 23
 24static void __init sun8i_a23_mbus_setup(struct device_node *node)
 25{
 26	int num_parents = of_clk_get_parent_count(node);
 27	const char **parents;
 28	const char *clk_name = node->name;
 29	struct resource res;
 30	struct clk_divider *div;
 31	struct clk_gate *gate;
 32	struct clk_mux *mux;
 33	struct clk *clk;
 34	void __iomem *reg;
 35	int err;
 36
 37	parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
 38	if (!parents)
 39		return;
 40
 41	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
 42	if (IS_ERR(reg)) {
 43		pr_err("Could not get registers for sun8i-mbus-clk\n");
 44		goto err_free_parents;
 45	}
 46
 47	div = kzalloc(sizeof(*div), GFP_KERNEL);
 48	if (!div)
 49		goto err_unmap;
 50
 51	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
 52	if (!mux)
 53		goto err_free_div;
 54
 55	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 56	if (!gate)
 57		goto err_free_mux;
 58
 59	of_property_read_string(node, "clock-output-names", &clk_name);
 60	of_clk_parent_fill(node, parents, num_parents);
 61
 62	gate->reg = reg;
 63	gate->bit_idx = SUN8I_MBUS_ENABLE;
 64	gate->lock = &sun8i_a23_mbus_lock;
 65
 66	div->reg = reg;
 67	div->shift = SUN8I_MBUS_DIV_SHIFT;
 68	div->width = SUN8I_MBUS_DIV_WIDTH;
 69	div->lock = &sun8i_a23_mbus_lock;
 70
 71	mux->reg = reg;
 72	mux->shift = SUN8I_MBUS_MUX_SHIFT;
 73	mux->mask = SUN8I_MBUS_MUX_MASK;
 74	mux->lock = &sun8i_a23_mbus_lock;
 75
 76	/* The MBUS clocks needs to be always enabled */
 77	clk = clk_register_composite(NULL, clk_name, parents, num_parents,
 78				     &mux->hw, &clk_mux_ops,
 79				     &div->hw, &clk_divider_ops,
 80				     &gate->hw, &clk_gate_ops,
 81				     CLK_IS_CRITICAL);
 82	if (IS_ERR(clk))
 83		goto err_free_gate;
 84
 85	err = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 86	if (err)
 87		goto err_unregister_clk;
 88
 89	kfree(parents); /* parents is deep copied */
 90
 91	return;
 92
 93err_unregister_clk:
 94	/* TODO: The composite clock stuff will leak a bit here. */
 95	clk_unregister(clk);
 96err_free_gate:
 97	kfree(gate);
 98err_free_mux:
 99	kfree(mux);
100err_free_div:
101	kfree(div);
102err_unmap:
103	iounmap(reg);
104	of_address_to_resource(node, 0, &res);
105	release_mem_region(res.start, resource_size(&res));
106err_free_parents:
107	kfree(parents);
108}
109CLK_OF_DECLARE(sun8i_a23_mbus, "allwinner,sun8i-a23-mbus-clk", sun8i_a23_mbus_setup);