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Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Przemyslaw Marczak3b3ad902015-10-27 13:08:01 +01002/*
3 * Copyright (C) 2015 Samsung Electronics
4 * Przemyslaw Marczak <p.marczak@samsung.com>
Przemyslaw Marczak3b3ad902015-10-27 13:08:01 +01005 */
6#include <common.h>
7#include <errno.h>
8#include <dm.h>
9#include <adc.h>
10#include <asm/arch/adc.h>
11
12struct exynos_adc_priv {
13 int active_channel;
14 struct exynos_adc_v2 *regs;
15};
16
17int exynos_adc_channel_data(struct udevice *dev, int channel,
18 unsigned int *data)
19{
20 struct exynos_adc_priv *priv = dev_get_priv(dev);
21 struct exynos_adc_v2 *regs = priv->regs;
22
23 if (channel != priv->active_channel) {
Masahiro Yamada9b643e32017-09-16 14:10:41 +090024 pr_err("Requested channel is not active!");
Przemyslaw Marczak3b3ad902015-10-27 13:08:01 +010025 return -EINVAL;
26 }
27
28 if (ADC_V2_GET_STATUS_FLAG(readl(&regs->status)) != FLAG_CONV_END)
29 return -EBUSY;
30
31 *data = readl(&regs->dat) & ADC_V2_DAT_MASK;
32
33 return 0;
34}
35
36int exynos_adc_start_channel(struct udevice *dev, int channel)
37{
38 struct exynos_adc_priv *priv = dev_get_priv(dev);
39 struct exynos_adc_v2 *regs = priv->regs;
40 unsigned int cfg;
41
42 /* Choose channel */
43 cfg = readl(&regs->con2);
44 cfg &= ~ADC_V2_CON2_CHAN_SEL_MASK;
45 cfg |= ADC_V2_CON2_CHAN_SEL(channel);
46 writel(cfg, &regs->con2);
47
48 /* Start conversion */
49 cfg = readl(&regs->con1);
50 writel(cfg | ADC_V2_CON1_STC_EN, &regs->con1);
51
52 priv->active_channel = channel;
53
54 return 0;
55}
56
57int exynos_adc_stop(struct udevice *dev)
58{
59 struct exynos_adc_priv *priv = dev_get_priv(dev);
60 struct exynos_adc_v2 *regs = priv->regs;
61 unsigned int cfg;
62
63 /* Stop conversion */
64 cfg = readl(&regs->con1);
Krzysztof Kozlowski6e74c6a2019-03-06 19:37:49 +010065 cfg &= ~ADC_V2_CON1_STC_EN;
Przemyslaw Marczak3b3ad902015-10-27 13:08:01 +010066
67 writel(cfg, &regs->con1);
68
69 priv->active_channel = -1;
70
71 return 0;
72}
73
74int exynos_adc_probe(struct udevice *dev)
75{
76 struct exynos_adc_priv *priv = dev_get_priv(dev);
77 struct exynos_adc_v2 *regs = priv->regs;
78 unsigned int cfg;
79
80 /* Check HW version */
81 if (readl(&regs->version) != ADC_V2_VERSION) {
Masahiro Yamada9b643e32017-09-16 14:10:41 +090082 pr_err("This driver supports only ADC v2!");
Przemyslaw Marczak3b3ad902015-10-27 13:08:01 +010083 return -ENXIO;
84 }
85
86 /* ADC Reset */
87 writel(ADC_V2_CON1_SOFT_RESET, &regs->con1);
88
89 /* Disable INT - will read status only */
90 writel(0x0, &regs->int_en);
91
92 /* CON2 - set conversion parameters */
93 cfg = ADC_V2_CON2_C_TIME(3); /* Conversion times: (1 << 3) = 8 */
94 cfg |= ADC_V2_CON2_OSEL(OSEL_BINARY);
95 cfg |= ADC_V2_CON2_ESEL(ESEL_ADC_EVAL_TIME_20CLK);
96 cfg |= ADC_V2_CON2_HIGHF(HIGHF_CONV_RATE_600KSPS);
97 writel(cfg, &regs->con2);
98
99 priv->active_channel = -1;
100
101 return 0;
102}
103
104int exynos_adc_ofdata_to_platdata(struct udevice *dev)
105{
106 struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
107 struct exynos_adc_priv *priv = dev_get_priv(dev);
108
Simon Glassa821c4a2017-05-17 17:18:05 -0600109 priv->regs = (struct exynos_adc_v2 *)devfdt_get_addr(dev);
Przemyslaw Marczak3b3ad902015-10-27 13:08:01 +0100110 if (priv->regs == (struct exynos_adc_v2 *)FDT_ADDR_T_NONE) {
Masahiro Yamada9b643e32017-09-16 14:10:41 +0900111 pr_err("Dev: %s - can't get address!", dev->name);
Przemyslaw Marczak3b3ad902015-10-27 13:08:01 +0100112 return -ENODATA;
113 }
114
115 uc_pdata->data_mask = ADC_V2_DAT_MASK;
116 uc_pdata->data_format = ADC_DATA_FORMAT_BIN;
117 uc_pdata->data_timeout_us = ADC_V2_CONV_TIMEOUT_US;
118
119 /* Mask available channel bits: [0:9] */
120 uc_pdata->channel_mask = (2 << ADC_V2_MAX_CHANNEL) - 1;
121
122 return 0;
123}
124
125static const struct adc_ops exynos_adc_ops = {
126 .start_channel = exynos_adc_start_channel,
127 .channel_data = exynos_adc_channel_data,
128 .stop = exynos_adc_stop,
129};
130
131static const struct udevice_id exynos_adc_ids[] = {
132 { .compatible = "samsung,exynos-adc-v2" },
133 { }
134};
135
136U_BOOT_DRIVER(exynos_adc) = {
137 .name = "exynos-adc",
138 .id = UCLASS_ADC,
139 .of_match = exynos_adc_ids,
140 .ops = &exynos_adc_ops,
141 .probe = exynos_adc_probe,
142 .ofdata_to_platdata = exynos_adc_ofdata_to_platdata,
143 .priv_auto_alloc_size = sizeof(struct exynos_adc_priv),
144};