2 * Copyright 2014 Chen-Yu Tsai
4 * Chen-Yu Tsai <wens@csie.org>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
17 #include <linux/clk.h>
18 #include <linux/clk-provider.h>
19 #include <linux/of_address.h>
21 #include "clk-factors.h"
24 * sun8i_a23_get_mbus_factors() - calculates m factor for MBUS clocks
25 * MBUS rate is calculated as follows
26 * rate = parent_rate / (m + 1);
29 static void sun8i_a23_get_mbus_factors(struct factors_request *req)
34 * These clocks can only divide, so we will never be able to
35 * achieve frequencies higher than the parent frequency
37 if (req->rate > req->parent_rate)
38 req->rate = req->parent_rate;
40 div = DIV_ROUND_UP(req->parent_rate, req->rate);
45 req->rate = req->parent_rate / div;
49 static struct clk_factors_config sun8i_a23_mbus_config = {
54 static const struct factors_data sun8i_a23_mbus_data __initconst = {
57 .muxmask = BIT(1) | BIT(0),
58 .table = &sun8i_a23_mbus_config,
59 .getter = sun8i_a23_get_mbus_factors,
62 static DEFINE_SPINLOCK(sun8i_a23_mbus_lock);
64 static void __init sun8i_a23_mbus_setup(struct device_node *node)
69 reg = of_iomap(node, 0);
71 pr_err("Could not get registers for a23-mbus-clk\n");
75 mbus = sunxi_factors_register(node, &sun8i_a23_mbus_data,
76 &sun8i_a23_mbus_lock, reg);
78 /* The MBUS clocks needs to be always enabled */
80 clk_prepare_enable(mbus);
82 CLK_OF_DECLARE(sun8i_a23_mbus, "allwinner,sun8i-a23-mbus-clk", sun8i_a23_mbus_setup);