/* * Copyright 2014 Chen-Yu Tsai * * Chen-Yu Tsai <wens@csie.org> * * 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.h> #include <linux/clk-provider.h> #include <linux/of_address.h> #include "clk-factors.h" /** * sun8i_a23_get_mbus_factors() - calculates m factor for MBUS clocks * MBUS rate is calculated as follows * rate = parent_rate / (m + 1); */ static void sun8i_a23_get_mbus_factors(u32 *freq, u32 parent_rate, u8 *n, u8 *k, u8 *m, u8 *p) { u8 div; /* * These clocks can only divide, so we will never be able to * achieve frequencies higher than the parent frequency */ if (*freq > parent_rate) *freq = parent_rate; div = DIV_ROUND_UP(parent_rate, *freq); if (div > 8) div = 8; *freq = parent_rate / div; /* we were called to round the frequency, we can now return */ if (m == NULL) return; *m = div - 1; } static struct clk_factors_config sun8i_a23_mbus_config = { .mshift = 0, .mwidth = 3, }; static const struct factors_data sun8i_a23_mbus_data __initconst = { .enable = 31, .mux = 24, .muxmask = BIT(1) | BIT(0), .table = &sun8i_a23_mbus_config, .getter = sun8i_a23_get_mbus_factors, }; static DEFINE_SPINLOCK(sun8i_a23_mbus_lock); static void __init sun8i_a23_mbus_setup(struct device_node *node) { struct clk *mbus; void __iomem *reg; reg = of_iomap(node, 0); if (!reg) { pr_err("Could not get registers for a23-mbus-clk\n"); return; } mbus = sunxi_factors_register(node, &sun8i_a23_mbus_data, &sun8i_a23_mbus_lock, reg); /* The MBUS clocks needs to be always enabled */ __clk_get(mbus); clk_prepare_enable(mbus); } CLK_OF_DECLARE(sun8i_a23_mbus, "allwinner,sun8i-a23-mbus-clk", sun8i_a23_mbus_setup);