1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2016 Imagination Technologies
4 */
5
6 #include <common.h>
7 #include <clk-uclass.h>
8 #include <dm.h>
9 #include <dt-bindings/clock/boston-clock.h>
10 #include <regmap.h>
11 #include <syscon.h>
12 #include <linux/bitops.h>
13
14 struct clk_boston {
15 struct regmap *regmap;
16 };
17
18 #define BOSTON_PLAT_MMCMDIV 0x30
19 # define BOSTON_PLAT_MMCMDIV_CLK0DIV (0xff << 0)
20 # define BOSTON_PLAT_MMCMDIV_INPUT (0xff << 8)
21 # define BOSTON_PLAT_MMCMDIV_MUL (0xff << 16)
22 # define BOSTON_PLAT_MMCMDIV_CLK1DIV (0xff << 24)
23
ext_field(uint32_t val,uint32_t mask)24 static uint32_t ext_field(uint32_t val, uint32_t mask)
25 {
26 return (val & mask) >> (ffs(mask) - 1);
27 }
28
clk_boston_get_rate(struct clk * clk)29 static ulong clk_boston_get_rate(struct clk *clk)
30 {
31 struct clk_boston *state = dev_get_plat(clk->dev);
32 uint32_t in_rate, mul, div;
33 uint mmcmdiv;
34 int err;
35
36 err = regmap_read(state->regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv);
37 if (err)
38 return 0;
39
40 in_rate = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT);
41 mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL);
42
43 switch (clk->id) {
44 case BOSTON_CLK_SYS:
45 div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV);
46 break;
47 case BOSTON_CLK_CPU:
48 div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV);
49 break;
50 default:
51 return 0;
52 }
53
54 return (in_rate * mul * 1000000) / div;
55 }
56
57 const struct clk_ops clk_boston_ops = {
58 .get_rate = clk_boston_get_rate,
59 };
60
clk_boston_of_to_plat(struct udevice * dev)61 static int clk_boston_of_to_plat(struct udevice *dev)
62 {
63 struct clk_boston *state = dev_get_plat(dev);
64 struct udevice *syscon;
65 int err;
66
67 err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
68 "regmap", &syscon);
69 if (err) {
70 pr_err("unable to find syscon device\n");
71 return err;
72 }
73
74 state->regmap = syscon_get_regmap(syscon);
75 if (!state->regmap) {
76 pr_err("unable to find regmap\n");
77 return -ENODEV;
78 }
79
80 return 0;
81 }
82
83 static const struct udevice_id clk_boston_match[] = {
84 {
85 .compatible = "img,boston-clock",
86 },
87 { /* sentinel */ }
88 };
89
90 U_BOOT_DRIVER(clk_boston) = {
91 .name = "boston_clock",
92 .id = UCLASS_CLK,
93 .of_match = clk_boston_match,
94 .of_to_plat = clk_boston_of_to_plat,
95 .plat_auto = sizeof(struct clk_boston),
96 .ops = &clk_boston_ops,
97 };
98