xref: /openbmc/u-boot/arch/mips/mach-ath79/ar933x/clk.c (revision e8f80a5a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2015-2016 Wills Wang <wills.wang@live.com>
4  */
5 
6 #include <common.h>
7 #include <asm/io.h>
8 #include <asm/addrspace.h>
9 #include <asm/types.h>
10 #include <mach/ar71xx_regs.h>
11 #include <mach/ath79.h>
12 
13 DECLARE_GLOBAL_DATA_PTR;
14 
ar933x_get_xtal(void)15 static u32 ar933x_get_xtal(void)
16 {
17 	u32 val;
18 
19 	val = ath79_get_bootstrap();
20 	if (val & AR933X_BOOTSTRAP_REF_CLK_40)
21 		return 40000000;
22 	else
23 		return 25000000;
24 }
25 
get_serial_clock(void)26 int get_serial_clock(void)
27 {
28 	return ar933x_get_xtal();
29 }
30 
get_clocks(void)31 int get_clocks(void)
32 {
33 	void __iomem *regs;
34 	u32 val, xtal, pll, div;
35 
36 	regs = map_physmem(AR71XX_PLL_BASE, AR71XX_PLL_SIZE,
37 			   MAP_NOCACHE);
38 	xtal = ar933x_get_xtal();
39 	val = readl(regs + AR933X_PLL_CPU_CONFIG_REG);
40 
41 	/* VCOOUT = XTAL * DIV_INT */
42 	div = (val >> AR933X_PLL_CPU_CONFIG_REFDIV_SHIFT)
43 			& AR933X_PLL_CPU_CONFIG_REFDIV_MASK;
44 	pll = xtal / div;
45 
46 	/* PLLOUT = VCOOUT * (1/2^OUTDIV) */
47 	div = (val >> AR933X_PLL_CPU_CONFIG_NINT_SHIFT)
48 			& AR933X_PLL_CPU_CONFIG_NINT_MASK;
49 	pll *= div;
50 	div = (val >> AR933X_PLL_CPU_CONFIG_OUTDIV_SHIFT)
51 			& AR933X_PLL_CPU_CONFIG_OUTDIV_MASK;
52 	if (!div)
53 		div = 1;
54 	pll >>= div;
55 
56 	val = readl(regs + AR933X_PLL_CLK_CTRL_REG);
57 
58 	/* CPU_CLK = PLLOUT / CPU_POST_DIV */
59 	div = ((val >> AR933X_PLL_CLK_CTRL_CPU_POST_DIV_SHIFT)
60 			& AR933X_PLL_CLK_CTRL_CPU_POST_DIV_MASK) + 1;
61 	gd->cpu_clk = pll / div;
62 
63 	/* DDR_CLK = PLLOUT / DDR_POST_DIV */
64 	div = ((val >> AR933X_PLL_CLK_CTRL_DDR_POST_DIV_SHIFT)
65 			& AR933X_PLL_CLK_CTRL_DDR_POST_DIV_MASK) + 1;
66 	gd->mem_clk = pll / div;
67 
68 	/* AHB_CLK = PLLOUT / AHB_POST_DIV */
69 	div = ((val >> AR933X_PLL_CLK_CTRL_AHB_POST_DIV_SHIFT)
70 			& AR933X_PLL_CLK_CTRL_AHB_POST_DIV_MASK) + 1;
71 	gd->bus_clk = pll / div;
72 
73 	return 0;
74 }
75 
get_bus_freq(ulong dummy)76 ulong get_bus_freq(ulong dummy)
77 {
78 	if (!gd->bus_clk)
79 		get_clocks();
80 	return gd->bus_clk;
81 }
82 
get_ddr_freq(ulong dummy)83 ulong get_ddr_freq(ulong dummy)
84 {
85 	if (!gd->mem_clk)
86 		get_clocks();
87 	return gd->mem_clk;
88 }
89