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
|
/*
* Copyright (C) 2015 Samsung Electronics
* Przemyslaw Marczak <p.marczak@samsung.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <errno.h>
#include <dm.h>
#include <adc.h>
#include <asm/arch/adc.h>
struct exynos_adc_priv {
int active_channel;
struct exynos_adc_v2 *regs;
};
int exynos_adc_channel_data(struct udevice *dev, int channel,
unsigned int *data)
{
struct exynos_adc_priv *priv = dev_get_priv(dev);
struct exynos_adc_v2 *regs = priv->regs;
if (channel != priv->active_channel) {
error("Requested channel is not active!");
return -EINVAL;
}
if (ADC_V2_GET_STATUS_FLAG(readl(®s->status)) != FLAG_CONV_END)
return -EBUSY;
*data = readl(®s->dat) & ADC_V2_DAT_MASK;
return 0;
}
int exynos_adc_start_channel(struct udevice *dev, int channel)
{
struct exynos_adc_priv *priv = dev_get_priv(dev);
struct exynos_adc_v2 *regs = priv->regs;
unsigned int cfg;
/* Choose channel */
cfg = readl(®s->con2);
cfg &= ~ADC_V2_CON2_CHAN_SEL_MASK;
cfg |= ADC_V2_CON2_CHAN_SEL(channel);
writel(cfg, ®s->con2);
/* Start conversion */
cfg = readl(®s->con1);
writel(cfg | ADC_V2_CON1_STC_EN, ®s->con1);
priv->active_channel = channel;
return 0;
}
int exynos_adc_stop(struct udevice *dev)
{
struct exynos_adc_priv *priv = dev_get_priv(dev);
struct exynos_adc_v2 *regs = priv->regs;
unsigned int cfg;
/* Stop conversion */
cfg = readl(®s->con1);
cfg |= ~ADC_V2_CON1_STC_EN;
writel(cfg, ®s->con1);
priv->active_channel = -1;
return 0;
}
int exynos_adc_probe(struct udevice *dev)
{
struct exynos_adc_priv *priv = dev_get_priv(dev);
struct exynos_adc_v2 *regs = priv->regs;
unsigned int cfg;
/* Check HW version */
if (readl(®s->version) != ADC_V2_VERSION) {
error("This driver supports only ADC v2!");
return -ENXIO;
}
/* ADC Reset */
writel(ADC_V2_CON1_SOFT_RESET, ®s->con1);
/* Disable INT - will read status only */
writel(0x0, ®s->int_en);
/* CON2 - set conversion parameters */
cfg = ADC_V2_CON2_C_TIME(3); /* Conversion times: (1 << 3) = 8 */
cfg |= ADC_V2_CON2_OSEL(OSEL_BINARY);
cfg |= ADC_V2_CON2_ESEL(ESEL_ADC_EVAL_TIME_20CLK);
cfg |= ADC_V2_CON2_HIGHF(HIGHF_CONV_RATE_600KSPS);
writel(cfg, ®s->con2);
priv->active_channel = -1;
return 0;
}
int exynos_adc_ofdata_to_platdata(struct udevice *dev)
{
struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
struct exynos_adc_priv *priv = dev_get_priv(dev);
priv->regs = (struct exynos_adc_v2 *)dev_get_addr(dev);
if (priv->regs == (struct exynos_adc_v2 *)FDT_ADDR_T_NONE) {
error("Dev: %s - can't get address!", dev->name);
return -ENODATA;
}
uc_pdata->data_mask = ADC_V2_DAT_MASK;
uc_pdata->data_format = ADC_DATA_FORMAT_BIN;
uc_pdata->data_timeout_us = ADC_V2_CONV_TIMEOUT_US;
/* Mask available channel bits: [0:9] */
uc_pdata->channel_mask = (2 << ADC_V2_MAX_CHANNEL) - 1;
return 0;
}
static const struct adc_ops exynos_adc_ops = {
.start_channel = exynos_adc_start_channel,
.channel_data = exynos_adc_channel_data,
.stop = exynos_adc_stop,
};
static const struct udevice_id exynos_adc_ids[] = {
{ .compatible = "samsung,exynos-adc-v2" },
{ }
};
U_BOOT_DRIVER(exynos_adc) = {
.name = "exynos-adc",
.id = UCLASS_ADC,
.of_match = exynos_adc_ids,
.ops = &exynos_adc_ops,
.probe = exynos_adc_probe,
.ofdata_to_platdata = exynos_adc_ofdata_to_platdata,
.priv_auto_alloc_size = sizeof(struct exynos_adc_priv),
};
|
