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Wolfram Sanga6659622014-03-07 17:00:37 +01001/*
2 * rz Core CPG Clocks
3 *
4 * Copyright (C) 2013 Ideas On Board SPRL
5 * Copyright (C) 2014 Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; version 2 of the License.
10 */
11
12#include <linux/clk-provider.h>
Simon Horman09c32422016-03-08 09:42:07 +090013#include <linux/clk/renesas.h>
Wolfram Sanga6659622014-03-07 17:00:37 +010014#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18#include <linux/slab.h>
19
20struct rz_cpg {
21 struct clk_onecell_data data;
22 void __iomem *reg;
23};
24
25#define CPG_FRQCR 0x10
26#define CPG_FRQCR2 0x14
27
Chris Brandtb452dfe2016-09-01 22:32:25 -040028#define PPR0 0xFCFE3200
29#define PIBC0 0xFCFE7000
30
31#define MD_CLK(x) ((x >> 2) & 1) /* P0_2 */
32
Wolfram Sanga6659622014-03-07 17:00:37 +010033/* -----------------------------------------------------------------------------
34 * Initialization
35 */
36
Chris Brandtb452dfe2016-09-01 22:32:25 -040037static u16 __init rz_cpg_read_mode_pins(void)
38{
39 void __iomem *ppr0, *pibc0;
40 u16 modes;
41
42 ppr0 = ioremap_nocache(PPR0, 2);
43 pibc0 = ioremap_nocache(PIBC0, 2);
44 BUG_ON(!ppr0 || !pibc0);
45 iowrite16(4, pibc0); /* enable input buffer */
46 modes = ioread16(ppr0);
47 iounmap(ppr0);
48 iounmap(pibc0);
49
50 return modes;
51}
52
Wolfram Sanga6659622014-03-07 17:00:37 +010053static struct clk * __init
54rz_cpg_register_clock(struct device_node *np, struct rz_cpg *cpg, const char *name)
55{
56 u32 val;
57 unsigned mult;
58 static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 };
59
60 if (strcmp(name, "pll") == 0) {
Chris Brandtb452dfe2016-09-01 22:32:25 -040061 unsigned int cpg_mode = MD_CLK(rz_cpg_read_mode_pins());
Wolfram Sanga6659622014-03-07 17:00:37 +010062 const char *parent_name = of_clk_get_parent_name(np, cpg_mode);
63
64 mult = cpg_mode ? (32 / 4) : 30;
65
66 return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, 1);
67 }
68
69 /* If mapping regs failed, skip non-pll clocks. System will boot anyhow */
70 if (!cpg->reg)
71 return ERR_PTR(-ENXIO);
72
73 /* FIXME:"i" and "g" are variable clocks with non-integer dividers (e.g. 2/3)
74 * and the constraint that always g <= i. To get the rz platform started,
75 * let them run at fixed current speed and implement the details later.
76 */
77 if (strcmp(name, "i") == 0)
78 val = (clk_readl(cpg->reg + CPG_FRQCR) >> 8) & 3;
79 else if (strcmp(name, "g") == 0)
80 val = clk_readl(cpg->reg + CPG_FRQCR2) & 3;
81 else
82 return ERR_PTR(-EINVAL);
83
84 mult = frqcr_tab[val];
85 return clk_register_fixed_factor(NULL, name, "pll", 0, mult, 3);
86}
87
88static void __init rz_cpg_clocks_init(struct device_node *np)
89{
90 struct rz_cpg *cpg;
91 struct clk **clks;
92 unsigned i;
93 int num_clks;
94
95 num_clks = of_property_count_strings(np, "clock-output-names");
96 if (WARN(num_clks <= 0, "can't count CPG clocks\n"))
97 return;
98
99 cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
100 clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL);
101 BUG_ON(!cpg || !clks);
102
103 cpg->data.clks = clks;
104 cpg->data.clk_num = num_clks;
105
106 cpg->reg = of_iomap(np, 0);
107
108 for (i = 0; i < num_clks; ++i) {
109 const char *name;
110 struct clk *clk;
111
112 of_property_read_string_index(np, "clock-output-names", i, &name);
113
114 clk = rz_cpg_register_clock(np, cpg, name);
115 if (IS_ERR(clk))
116 pr_err("%s: failed to register %s %s clock (%ld)\n",
117 __func__, np->name, name, PTR_ERR(clk));
118 else
119 cpg->data.clks[i] = clk;
120 }
121
122 of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
Geert Uytterhoevenf04b4862015-08-04 14:28:06 +0200123
124 cpg_mstp_add_clk_domain(np);
Wolfram Sanga6659622014-03-07 17:00:37 +0100125}
126CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init);