diff options
author | Heiko Stübner <heiko@sntech.de> | 2014-07-03 01:58:39 +0200 |
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committer | Mike Turquette <mturquette@linaro.org> | 2014-07-13 12:17:06 -0700 |
commit | a245fecbb8064641d9cc317b347b5bdb2b7a4bb6 (patch) | |
tree | d4573cc7258ecc18e9db839f809960062ee419b0 /drivers/clk/rockchip/clk.c | |
parent | 5a994e151f7c54a5fdeb07fe2fed4ed64b9321b8 (diff) | |
download | op-kernel-dev-a245fecbb8064641d9cc317b347b5bdb2b7a4bb6.zip op-kernel-dev-a245fecbb8064641d9cc317b347b5bdb2b7a4bb6.tar.gz |
clk: rockchip: add basic infrastructure for clock branches
This adds infrastructure for registering clock branches. On Rockchip SoCs
most clock branches are a combination of mux,divider and gate components,
thus a composite clock is used when appropriate.
Clock branches are supposed to be declared in an array using the COMPOSITE*
or MUX, etc makros defined in the header and then registered using
rockchip_clk_register_branches.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-By: Max Schwarz <max.schwarz@online.de>
Tested-By: Max Schwarz <max.schwarz@online.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/rockchip/clk.c')
-rw-r--r-- | drivers/clk/rockchip/clk.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c new file mode 100644 index 0000000..aa15d5a --- /dev/null +++ b/drivers/clk/rockchip/clk.c @@ -0,0 +1,209 @@ +/* + * Copyright (c) 2014 MundoReader S.L. + * Author: Heiko Stuebner <heiko@sntech.de> + * + * based on + * + * samsung/clk.c + * Copyright (c) 2013 Samsung Electronics Co., Ltd. + * Copyright (c) 2013 Linaro Ltd. + * Author: Thomas Abraham <thomas.ab@samsung.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/slab.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include "clk.h" + +/** + * Register a clock branch. + * Most clock branches have a form like + * + * src1 --|--\ + * |M |--[GATE]-[DIV]- + * src2 --|--/ + * + * sometimes without one of those components. + */ +struct clk *rockchip_clk_register_branch(const char *name, + const char **parent_names, u8 num_parents, void __iomem *base, + int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags, + u8 div_shift, u8 div_width, u8 div_flags, + struct clk_div_table *div_table, int gate_offset, + u8 gate_shift, u8 gate_flags, unsigned long flags, + spinlock_t *lock) +{ + struct clk *clk; + struct clk_mux *mux = NULL; + struct clk_gate *gate = NULL; + struct clk_divider *div = NULL; + const struct clk_ops *mux_ops = NULL, *div_ops = NULL, + *gate_ops = NULL; + + if (num_parents > 1) { + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + return ERR_PTR(-ENOMEM); + + mux->reg = base + muxdiv_offset; + mux->shift = mux_shift; + mux->mask = BIT(mux_width) - 1; + mux->flags = mux_flags; + mux->lock = lock; + mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops + : &clk_mux_ops; + } + + if (gate_offset >= 0) { + gate = kzalloc(sizeof(*gate), GFP_KERNEL); + if (!gate) + return ERR_PTR(-ENOMEM); + + gate->flags = gate_flags; + gate->reg = base + gate_offset; + gate->bit_idx = gate_shift; + gate->lock = lock; + gate_ops = &clk_gate_ops; + } + + if (div_width > 0) { + div = kzalloc(sizeof(*div), GFP_KERNEL); + if (!div) + return ERR_PTR(-ENOMEM); + + div->flags = div_flags; + div->reg = base + muxdiv_offset; + div->shift = div_shift; + div->width = div_width; + div->lock = lock; + div->table = div_table; + div_ops = (div_flags & CLK_DIVIDER_READ_ONLY) + ? &clk_divider_ro_ops + : &clk_divider_ops; + } + + clk = clk_register_composite(NULL, name, parent_names, num_parents, + mux ? &mux->hw : NULL, mux_ops, + div ? &div->hw : NULL, div_ops, + gate ? &gate->hw : NULL, gate_ops, + flags); + + return clk; +} + +static DEFINE_SPINLOCK(clk_lock); +static struct clk **clk_table; +static void __iomem *reg_base; +static struct clk_onecell_data clk_data; + +void __init rockchip_clk_init(struct device_node *np, void __iomem *base, + unsigned long nr_clks) +{ + reg_base = base; + + clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL); + if (!clk_table) + pr_err("%s: could not allocate clock lookup table\n", __func__); + + clk_data.clks = clk_table; + clk_data.clk_num = nr_clks; + of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data); +} + +void rockchip_clk_add_lookup(struct clk *clk, unsigned int id) +{ + if (clk_table && id) + clk_table[id] = clk; +} + +void __init rockchip_clk_register_branches( + struct rockchip_clk_branch *list, + unsigned int nr_clk) +{ + struct clk *clk = NULL; + unsigned int idx; + unsigned long flags; + + for (idx = 0; idx < nr_clk; idx++, list++) { + flags = list->flags; + + /* catch simple muxes */ + switch (list->branch_type) { + case branch_mux: + clk = clk_register_mux(NULL, list->name, + list->parent_names, list->num_parents, + flags, reg_base + list->muxdiv_offset, + list->mux_shift, list->mux_width, + list->mux_flags, &clk_lock); + break; + case branch_divider: + if (list->div_table) + clk = clk_register_divider_table(NULL, + list->name, list->parent_names[0], + flags, reg_base + list->muxdiv_offset, + list->div_shift, list->div_width, + list->div_flags, list->div_table, + &clk_lock); + else + clk = clk_register_divider(NULL, list->name, + list->parent_names[0], flags, + reg_base + list->muxdiv_offset, + list->div_shift, list->div_width, + list->div_flags, &clk_lock); + break; + case branch_fraction_divider: + /* unimplemented */ + continue; + break; + case branch_gate: + flags |= CLK_SET_RATE_PARENT; + + /* keep all gates untouched for now */ + flags |= CLK_IGNORE_UNUSED; + + clk = clk_register_gate(NULL, list->name, + list->parent_names[0], flags, + reg_base + list->gate_offset, + list->gate_shift, list->gate_flags, &clk_lock); + break; + case branch_composite: + /* keep all gates untouched for now */ + flags |= CLK_IGNORE_UNUSED; + + clk = rockchip_clk_register_branch(list->name, + list->parent_names, list->num_parents, + reg_base, list->muxdiv_offset, list->mux_shift, + list->mux_width, list->mux_flags, + list->div_shift, list->div_width, + list->div_flags, list->div_table, + list->gate_offset, list->gate_shift, + list->gate_flags, flags, &clk_lock); + break; + } + + /* none of the cases above matched */ + if (!clk) { + pr_err("%s: unknown clock type %d\n", + __func__, list->branch_type); + continue; + } + + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock %s: %ld\n", + __func__, list->name, PTR_ERR(clk)); + continue; + } + + rockchip_clk_add_lookup(clk, list->id); + } +} |