tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#include <linux/kernel.h>
2#include <linux/clk-provider.h>
3#include <linux/of_address.h>
4#include <linux/init.h>
5#include <linux/io.h>
6
7static struct clk *out[2];
8static struct clk_onecell_data clk_data = { out, 2 };
9
10#define SYSCLK_CTRL 0x20
11#define CPUCLK_CTRL 0x24
12#define LEGACY_DIV 0x3c
13
14#define PLL_N(val) (((val) >> 0) & 0x7f)
15#define PLL_K(val) (((val) >> 13) & 0x7)
16#define PLL_M(val) (((val) >> 16) & 0x7)
17#define DIV_INDEX(val) (((val) >> 8) & 0xf)
18
19static void __init make_pll(int idx, const char *parent, void __iomem *base)
20{
21 char name[8];
22 u32 val, mul, div;
23
24 sprintf(name, "pll%d", idx);
25 val = readl_relaxed(base + idx*8);
26 mul = PLL_N(val) + 1;
27 div = (PLL_M(val) + 1) << PLL_K(val);
28 clk_register_fixed_factor(NULL, name, parent, 0, mul, div);
29}
30
31static int __init get_div(void __iomem *base)
32{
33 u8 sysclk_tab[16] = { 2, 4, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4 };
34 int idx = DIV_INDEX(readl_relaxed(base + LEGACY_DIV));
35
36 return sysclk_tab[idx];
37}
38
39static void __init tango4_clkgen_setup(struct device_node *np)
40{
41 int div, ret;
42 void __iomem *base = of_iomap(np, 0);
43 const char *parent = of_clk_get_parent_name(np, 0);
44
45 if (!base)
46 panic("%s: invalid address\n", np->full_name);
47
48 make_pll(0, parent, base);
49 make_pll(1, parent, base);
50
51 out[0] = clk_register_divider(NULL, "cpuclk", "pll0", 0,
52 base + CPUCLK_CTRL, 8, 8, CLK_DIVIDER_ONE_BASED, NULL);
53
54 div = readl_relaxed(base + SYSCLK_CTRL) & BIT(23) ? get_div(base) : 4;
55 out[1] = clk_register_fixed_factor(NULL, "sysclk", "pll1", 0, 1, div);
56
57 ret = of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
58 if (IS_ERR(out[0]) || IS_ERR(out[1]) || ret < 0)
59 panic("%s: clk registration failed\n", np->full_name);
60}
61CLK_OF_DECLARE(tango4_clkgen, "sigma,tango4-clkgen", tango4_clkgen_setup);