1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/*
* Copyright (c) 2017 BayLibre, SAS.
* Author: Neil Armstrong <narmstrong@baylibre.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <linux/clk-provider.h>
#include <linux/bitfield.h>
#include <linux/regmap.h>
#include "gxbb-aoclk.h"
/*
* The AO Domain embeds a dual/divider to generate a more precise
* 32,768KHz clock for low-power suspend mode and CEC.
* ______ ______
* | | | |
* ______ | Div1 |-| Cnt1 | ______
* | | /|______| |______|\ | |
* Xtal-->| Gate |---| ______ ______ X-X--| Gate |-->
* |______| | \| | | |/ | |______|
* | | Div2 |-| Cnt2 | |
* | |______| |______| |
* |_______________________|
*
* The dividing can be switched to single or dual, with a counter
* for each divider to set when the switching is done.
* The entire dividing mechanism can be also bypassed.
*/
#define CLK_CNTL0_N1_MASK GENMASK(11, 0)
#define CLK_CNTL0_N2_MASK GENMASK(23, 12)
#define CLK_CNTL0_DUALDIV_EN BIT(28)
#define CLK_CNTL0_OUT_GATE_EN BIT(30)
#define CLK_CNTL0_IN_GATE_EN BIT(31)
#define CLK_CNTL1_M1_MASK GENMASK(11, 0)
#define CLK_CNTL1_M2_MASK GENMASK(23, 12)
#define CLK_CNTL1_BYPASS_EN BIT(24)
#define CLK_CNTL1_SELECT_OSC BIT(27)
#define PWR_CNTL_ALT_32K_SEL GENMASK(13, 10)
struct cec_32k_freq_table {
unsigned long parent_rate;
unsigned long target_rate;
bool dualdiv;
unsigned int n1;
unsigned int n2;
unsigned int m1;
unsigned int m2;
};
static const struct cec_32k_freq_table aoclk_cec_32k_table[] = {
[0] = {
.parent_rate = 24000000,
.target_rate = 32768,
.dualdiv = true,
.n1 = 733,
.n2 = 732,
.m1 = 8,
.m2 = 11,
},
};
/*
* If CLK_CNTL0_DUALDIV_EN == 0
* - will use N1 divider only
* If CLK_CNTL0_DUALDIV_EN == 1
* - hold M1 cycles of N1 divider then changes to N2
* - hold M2 cycles of N2 divider then changes to N1
* Then we can get more accurate division.
*/
static unsigned long aoclk_cec_32k_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct aoclk_cec_32k *cec_32k = to_aoclk_cec_32k(hw);
unsigned long n1;
u32 reg0, reg1;
regmap_read(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0, ®0);
regmap_read(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL1, ®1);
if (reg1 & CLK_CNTL1_BYPASS_EN)
return parent_rate;
if (reg0 & CLK_CNTL0_DUALDIV_EN) {
unsigned long n2, m1, m2, f1, f2, p1, p2;
n1 = FIELD_GET(CLK_CNTL0_N1_MASK, reg0) + 1;
n2 = FIELD_GET(CLK_CNTL0_N2_MASK, reg0) + 1;
m1 = FIELD_GET(CLK_CNTL1_M1_MASK, reg1) + 1;
m2 = FIELD_GET(CLK_CNTL1_M2_MASK, reg1) + 1;
f1 = DIV_ROUND_CLOSEST(parent_rate, n1);
f2 = DIV_ROUND_CLOSEST(parent_rate, n2);
p1 = DIV_ROUND_CLOSEST(100000000 * m1, f1 * (m1 + m2));
p2 = DIV_ROUND_CLOSEST(100000000 * m2, f2 * (m1 + m2));
return DIV_ROUND_UP(100000000, p1 + p2);
}
n1 = FIELD_GET(CLK_CNTL0_N1_MASK, reg0) + 1;
return DIV_ROUND_CLOSEST(parent_rate, n1);
}
static const struct cec_32k_freq_table *find_cec_32k_freq(unsigned long rate,
unsigned long prate)
{
int i;
for (i = 0 ; i < ARRAY_SIZE(aoclk_cec_32k_table) ; ++i)
if (aoclk_cec_32k_table[i].parent_rate == prate &&
aoclk_cec_32k_table[i].target_rate == rate)
return &aoclk_cec_32k_table[i];
return NULL;
}
static long aoclk_cec_32k_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
const struct cec_32k_freq_table *freq = find_cec_32k_freq(rate,
*prate);
/* If invalid return first one */
if (!freq)
return aoclk_cec_32k_table[0].target_rate;
return freq->target_rate;
}
/*
* From the Amlogic init procedure, the IN and OUT gates needs to be handled
* in the init procedure to avoid any glitches.
*/
static int aoclk_cec_32k_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
const struct cec_32k_freq_table *freq = find_cec_32k_freq(rate,
parent_rate);
struct aoclk_cec_32k *cec_32k = to_aoclk_cec_32k(hw);
u32 reg = 0;
if (!freq)
return -EINVAL;
/* Disable clock */
regmap_update_bits(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0,
CLK_CNTL0_IN_GATE_EN | CLK_CNTL0_OUT_GATE_EN, 0);
reg = FIELD_PREP(CLK_CNTL0_N1_MASK, freq->n1 - 1);
if (freq->dualdiv)
reg |= CLK_CNTL0_DUALDIV_EN |
FIELD_PREP(CLK_CNTL0_N2_MASK, freq->n2 - 1);
regmap_write(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0, reg);
reg = FIELD_PREP(CLK_CNTL1_M1_MASK, freq->m1 - 1);
if (freq->dualdiv)
reg |= FIELD_PREP(CLK_CNTL1_M2_MASK, freq->m2 - 1);
regmap_write(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL1, reg);
/* Enable clock */
regmap_update_bits(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0,
CLK_CNTL0_IN_GATE_EN, CLK_CNTL0_IN_GATE_EN);
udelay(200);
regmap_update_bits(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0,
CLK_CNTL0_OUT_GATE_EN, CLK_CNTL0_OUT_GATE_EN);
regmap_update_bits(cec_32k->regmap, AO_CRT_CLK_CNTL1,
CLK_CNTL1_SELECT_OSC, CLK_CNTL1_SELECT_OSC);
/* Select 32k from XTAL */
regmap_update_bits(cec_32k->regmap,
AO_RTI_PWR_CNTL_REG0,
PWR_CNTL_ALT_32K_SEL,
FIELD_PREP(PWR_CNTL_ALT_32K_SEL, 4));
return 0;
}
const struct clk_ops meson_aoclk_cec_32k_ops = {
.recalc_rate = aoclk_cec_32k_recalc_rate,
.round_rate = aoclk_cec_32k_round_rate,
.set_rate = aoclk_cec_32k_set_rate,
};
|
