1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * RZ/A1 Core CPG Clocks
4 *
5 * Copyright (C) 2013 Ideas On Board SPRL
6 * Copyright (C) 2014 Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
7 */
8
9 #include <linux/clk-provider.h>
10 #include <linux/clk/renesas.h>
11 #include <linux/init.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/of.h>
15 #include <linux/of_address.h>
16 #include <linux/slab.h>
17
18 #define CPG_FRQCR 0x10
19 #define CPG_FRQCR2 0x14
20
21 #define PPR0 0xFCFE3200
22 #define PIBC0 0xFCFE7000
23
24 #define MD_CLK(x) ((x >> 2) & 1) /* P0_2 */
25
26 /* -----------------------------------------------------------------------------
27 * Initialization
28 */
29
rz_cpg_read_mode_pins(void)30 static u16 __init rz_cpg_read_mode_pins(void)
31 {
32 void __iomem *ppr0, *pibc0;
33 u16 modes;
34
35 ppr0 = ioremap(PPR0, 2);
36 pibc0 = ioremap(PIBC0, 2);
37 BUG_ON(!ppr0 || !pibc0);
38 iowrite16(4, pibc0); /* enable input buffer */
39 modes = ioread16(ppr0);
40 iounmap(ppr0);
41 iounmap(pibc0);
42
43 return modes;
44 }
45
46 static struct clk * __init
rz_cpg_register_clock(struct device_node * np,void __iomem * base,const char * name)47 rz_cpg_register_clock(struct device_node *np, void __iomem *base,
48 const char *name)
49 {
50 u32 val;
51 unsigned mult;
52 static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 };
53
54 if (strcmp(name, "pll") == 0) {
55 unsigned int cpg_mode = MD_CLK(rz_cpg_read_mode_pins());
56 const char *parent_name = of_clk_get_parent_name(np, cpg_mode);
57
58 mult = cpg_mode ? (32 / 4) : 30;
59
60 return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, 1);
61 }
62
63 /* If mapping regs failed, skip non-pll clocks. System will boot anyhow */
64 if (!base)
65 return ERR_PTR(-ENXIO);
66
67 /* FIXME:"i" and "g" are variable clocks with non-integer dividers (e.g. 2/3)
68 * and the constraint that always g <= i. To get the rz platform started,
69 * let them run at fixed current speed and implement the details later.
70 */
71 if (strcmp(name, "i") == 0)
72 val = (readl(base + CPG_FRQCR) >> 8) & 3;
73 else if (strcmp(name, "g") == 0)
74 val = readl(base + CPG_FRQCR2) & 3;
75 else
76 return ERR_PTR(-EINVAL);
77
78 mult = frqcr_tab[val];
79 return clk_register_fixed_factor(NULL, name, "pll", 0, mult, 3);
80 }
81
rz_cpg_clocks_init(struct device_node * np)82 static void __init rz_cpg_clocks_init(struct device_node *np)
83 {
84 struct clk_onecell_data *data;
85 struct clk **clks;
86 void __iomem *base;
87 unsigned i;
88 int num_clks;
89
90 num_clks = of_property_count_strings(np, "clock-output-names");
91 if (WARN(num_clks <= 0, "can't count CPG clocks\n"))
92 return;
93
94 data = kzalloc(sizeof(*data), GFP_KERNEL);
95 clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
96 BUG_ON(!data || !clks);
97
98 data->clks = clks;
99 data->clk_num = num_clks;
100
101 base = of_iomap(np, 0);
102
103 for (i = 0; i < num_clks; ++i) {
104 const char *name;
105 struct clk *clk;
106
107 of_property_read_string_index(np, "clock-output-names", i, &name);
108
109 clk = rz_cpg_register_clock(np, base, name);
110 if (IS_ERR(clk))
111 pr_err("%s: failed to register %pOFn %s clock (%ld)\n",
112 __func__, np, name, PTR_ERR(clk));
113 else
114 data->clks[i] = clk;
115 }
116
117 of_clk_add_provider(np, of_clk_src_onecell_get, data);
118
119 cpg_mstp_add_clk_domain(np);
120 }
121 CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init);
122