1/*
2 * OMAP clockdomain support
3 *
4 * Copyright (C) 2013 Texas Instruments, Inc.
5 *
6 * Tero Kristo <t-kristo@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
13 * kind, whether express or implied; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 */
17
18#include <linux/clk.h>
19#include <linux/clk-provider.h>
20#include <linux/slab.h>
21#include <linux/of.h>
22#include <linux/of_address.h>
23#include <linux/clk/ti.h>
24
25#include "clock.h"
26
27#undef pr_fmt
28#define pr_fmt(fmt) "%s: " fmt, __func__
29
30/**
31 * omap2_clkops_enable_clkdm - increment usecount on clkdm of @hw
32 * @hw: struct clk_hw * of the clock being enabled
33 *
34 * Increment the usecount of the clockdomain of the clock pointed to
35 * by @hw; if the usecount is 1, the clockdomain will be "enabled."
36 * Only needed for clocks that don't use omap2_dflt_clk_enable() as
37 * their enable function pointer.  Passes along the return value of
38 * clkdm_clk_enable(), -EINVAL if @hw is not associated with a
39 * clockdomain, or 0 if clock framework-based clockdomain control is
40 * not implemented.
41 */
42int omap2_clkops_enable_clkdm(struct clk_hw *hw)
43{
44	struct clk_hw_omap *clk;
45	int ret = 0;
46
47	clk = to_clk_hw_omap(hw);
48
49	if (unlikely(!clk->clkdm)) {
50		pr_err("%s: %s: no clkdm set ?!\n", __func__,
51		       clk_hw_get_name(hw));
52		return -EINVAL;
53	}
54
55	if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
56		pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
57		       __func__, clk_hw_get_name(hw));
58		return 0;
59	}
60
61	ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
62	WARN(ret, "%s: could not enable %s's clockdomain %s: %d\n",
63	     __func__, clk_hw_get_name(hw), clk->clkdm_name, ret);
64
65	return ret;
66}
67
68/**
69 * omap2_clkops_disable_clkdm - decrement usecount on clkdm of @hw
70 * @hw: struct clk_hw * of the clock being disabled
71 *
72 * Decrement the usecount of the clockdomain of the clock pointed to
73 * by @hw; if the usecount is 0, the clockdomain will be "disabled."
74 * Only needed for clocks that don't use omap2_dflt_clk_disable() as their
75 * disable function pointer.  No return value.
76 */
77void omap2_clkops_disable_clkdm(struct clk_hw *hw)
78{
79	struct clk_hw_omap *clk;
80
81	clk = to_clk_hw_omap(hw);
82
83	if (unlikely(!clk->clkdm)) {
84		pr_err("%s: %s: no clkdm set ?!\n", __func__,
85		       clk_hw_get_name(hw));
86		return;
87	}
88
89	if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
90		pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
91		       __func__, clk_hw_get_name(hw));
92		return;
93	}
94
95	ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
96}
97
98/**
99 * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
100 * @clk: OMAP clock struct ptr to use
101 *
102 * Convert a clockdomain name stored in a struct clk 'clk' into a
103 * clockdomain pointer, and save it into the struct clk.  Intended to be
104 * called during clk_register(). Returns 0 on success, -EERROR otherwise.
105 */
106int omap2_init_clk_clkdm(struct clk_hw *hw)
107{
108	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
109	struct clockdomain *clkdm;
110	const char *clk_name;
111
112	if (!clk->clkdm_name)
113		return 0;
114
115	clk_name = __clk_get_name(hw->clk);
116
117	clkdm = ti_clk_ll_ops->clkdm_lookup(clk->clkdm_name);
118	if (clkdm) {
119		pr_debug("clock: associated clk %s to clkdm %s\n",
120			 clk_name, clk->clkdm_name);
121		clk->clkdm = clkdm;
122	} else {
123		pr_debug("clock: could not associate clk %s to clkdm %s\n",
124			 clk_name, clk->clkdm_name);
125	}
126
127	return 0;
128}
129
130static void __init of_ti_clockdomain_setup(struct device_node *node)
131{
132	struct clk *clk;
133	struct clk_hw *clk_hw;
134	const char *clkdm_name = ti_dt_clk_name(node);
135	int i;
136	unsigned int num_clks;
137
138	num_clks = of_clk_get_parent_count(node);
139
140	for (i = 0; i < num_clks; i++) {
141		clk = of_clk_get(node, i);
142		if (IS_ERR(clk)) {
143			pr_err("%s: Failed get %pOF' clock nr %d (%ld)\n",
144			       __func__, node, i, PTR_ERR(clk));
145			continue;
146		}
147		clk_hw = __clk_get_hw(clk);
148		if (!omap2_clk_is_hw_omap(clk_hw)) {
149			pr_warn("can't setup clkdm for basic clk %s\n",
150				__clk_get_name(clk));
151			clk_put(clk);
152			continue;
153		}
154		to_clk_hw_omap(clk_hw)->clkdm_name = clkdm_name;
155		omap2_init_clk_clkdm(clk_hw);
156		clk_put(clk);
157	}
158}
159
160static const struct of_device_id ti_clkdm_match_table[] __initconst = {
161	{ .compatible = "ti,clockdomain" },
162	{ }
163};
164
165/**
166 * ti_dt_clockdomains_setup - setup device tree clockdomains
167 *
168 * Initializes clockdomain nodes for a SoC. This parses through all the
169 * nodes with compatible = "ti,clockdomain", and add the clockdomain
170 * info for all the clocks listed under these. This function shall be
171 * called after rest of the DT clock init has completed and all
172 * clock nodes have been registered.
173 */
174void __init ti_dt_clockdomains_setup(void)
175{
176	struct device_node *np;
177	for_each_matching_node(np, ti_clkdm_match_table) {
178		of_ti_clockdomain_setup(np);
179	}
180}
181