1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/clk-provider.h>
4 #include <linux/of_address.h>
5 #include <linux/init.h>
6 #include <linux/io.h>
7
8 #define CLK_COUNT 4 /* cpu_clk, sys_clk, usb_clk, sdio_clk */
9 static struct clk *clks[CLK_COUNT];
10 static struct clk_onecell_data clk_data = { clks, CLK_COUNT };
11
12 #define SYSCLK_DIV 0x20
13 #define CPUCLK_DIV 0x24
14 #define DIV_BYPASS BIT(23)
15
16 /*** CLKGEN_PLL ***/
17 #define extract_pll_n(val) ((val >> 0) & ((1u << 7) - 1))
18 #define extract_pll_k(val) ((val >> 13) & ((1u << 3) - 1))
19 #define extract_pll_m(val) ((val >> 16) & ((1u << 3) - 1))
20 #define extract_pll_isel(val) ((val >> 24) & ((1u << 3) - 1))
21
make_pll(int idx,const char * parent,void __iomem * base)22 static void __init make_pll(int idx, const char *parent, void __iomem *base)
23 {
24 char name[8];
25 u32 val, mul, div;
26
27 sprintf(name, "pll%d", idx);
28 val = readl(base + idx * 8);
29 mul = extract_pll_n(val) + 1;
30 div = (extract_pll_m(val) + 1) << extract_pll_k(val);
31 clk_register_fixed_factor(NULL, name, parent, 0, mul, div);
32 if (extract_pll_isel(val) != 1)
33 panic("%s: input not set to XTAL_IN\n", name);
34 }
35
make_cd(int idx,void __iomem * base)36 static void __init make_cd(int idx, void __iomem *base)
37 {
38 char name[8];
39 u32 val, mul, div;
40
41 sprintf(name, "cd%d", idx);
42 val = readl(base + idx * 8);
43 mul = 1 << 27;
44 div = (2 << 27) + val;
45 clk_register_fixed_factor(NULL, name, "pll2", 0, mul, div);
46 if (val > 0xf0000000)
47 panic("%s: unsupported divider %x\n", name, val);
48 }
49
tango4_clkgen_setup(struct device_node * np)50 static void __init tango4_clkgen_setup(struct device_node *np)
51 {
52 struct clk **pp = clk_data.clks;
53 void __iomem *base = of_iomap(np, 0);
54 const char *parent = of_clk_get_parent_name(np, 0);
55
56 if (!base)
57 panic("%pOFn: invalid address\n", np);
58
59 if (readl(base + CPUCLK_DIV) & DIV_BYPASS)
60 panic("%pOFn: unsupported cpuclk setup\n", np);
61
62 if (readl(base + SYSCLK_DIV) & DIV_BYPASS)
63 panic("%pOFn: unsupported sysclk setup\n", np);
64
65 writel(0x100, base + CPUCLK_DIV); /* disable frequency ramping */
66
67 make_pll(0, parent, base);
68 make_pll(1, parent, base);
69 make_pll(2, parent, base);
70 make_cd(2, base + 0x80);
71 make_cd(6, base + 0x80);
72
73 pp[0] = clk_register_divider(NULL, "cpu_clk", "pll0", 0,
74 base + CPUCLK_DIV, 8, 8, CLK_DIVIDER_ONE_BASED, NULL);
75 pp[1] = clk_register_fixed_factor(NULL, "sys_clk", "pll1", 0, 1, 4);
76 pp[2] = clk_register_fixed_factor(NULL, "usb_clk", "cd2", 0, 1, 2);
77 pp[3] = clk_register_fixed_factor(NULL, "sdio_clk", "cd6", 0, 1, 2);
78
79 if (IS_ERR(pp[0]) || IS_ERR(pp[1]) || IS_ERR(pp[2]) || IS_ERR(pp[3]))
80 panic("%pOFn: clk registration failed\n", np);
81
82 if (of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data))
83 panic("%pOFn: clk provider registration failed\n", np);
84 }
85 CLK_OF_DECLARE(tango4_clkgen, "sigma,tango4-clkgen", tango4_clkgen_setup);
86