summaryrefslogtreecommitdiffstats
path: root/drivers/iio/adc/mt6577_auxadc.c
blob: 414cf44bf19d0f7b16f7653cf6ff9523889765a0 (plain)
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
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
/*
 * Copyright (c) 2016 MediaTek Inc.
 * Author: Zhiyong Tao <zhiyong.tao@mediatek.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/iopoll.h>
#include <linux/io.h>
#include <linux/iio/iio.h>

/* Register definitions */
#define MT6577_AUXADC_CON0                    0x00
#define MT6577_AUXADC_CON1                    0x04
#define MT6577_AUXADC_CON2                    0x10
#define MT6577_AUXADC_STA                     BIT(0)

#define MT6577_AUXADC_DAT0                    0x14
#define MT6577_AUXADC_RDY0                    BIT(12)

#define MT6577_AUXADC_MISC                    0x94
#define MT6577_AUXADC_PDN_EN                  BIT(14)

#define MT6577_AUXADC_DAT_MASK                0xfff
#define MT6577_AUXADC_SLEEP_US                1000
#define MT6577_AUXADC_TIMEOUT_US              10000
#define MT6577_AUXADC_POWER_READY_MS          1
#define MT6577_AUXADC_SAMPLE_READY_US         25

struct mt6577_auxadc_device {
	void __iomem *reg_base;
	struct clk *adc_clk;
	struct mutex lock;
};

#define MT6577_AUXADC_CHANNEL(idx) {				    \
		.type = IIO_VOLTAGE,				    \
		.indexed = 1,					    \
		.channel = (idx),				    \
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
}

static const struct iio_chan_spec mt6577_auxadc_iio_channels[] = {
	MT6577_AUXADC_CHANNEL(0),
	MT6577_AUXADC_CHANNEL(1),
	MT6577_AUXADC_CHANNEL(2),
	MT6577_AUXADC_CHANNEL(3),
	MT6577_AUXADC_CHANNEL(4),
	MT6577_AUXADC_CHANNEL(5),
	MT6577_AUXADC_CHANNEL(6),
	MT6577_AUXADC_CHANNEL(7),
	MT6577_AUXADC_CHANNEL(8),
	MT6577_AUXADC_CHANNEL(9),
	MT6577_AUXADC_CHANNEL(10),
	MT6577_AUXADC_CHANNEL(11),
	MT6577_AUXADC_CHANNEL(12),
	MT6577_AUXADC_CHANNEL(13),
	MT6577_AUXADC_CHANNEL(14),
	MT6577_AUXADC_CHANNEL(15),
};

static inline void mt6577_auxadc_mod_reg(void __iomem *reg,
					 u32 or_mask, u32 and_mask)
{
	u32 val;

	val = readl(reg);
	val |= or_mask;
	val &= ~and_mask;
	writel(val, reg);
}

static int mt6577_auxadc_read(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan)
{
	u32 val;
	void __iomem *reg_channel;
	int ret;
	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);

	reg_channel = adc_dev->reg_base + MT6577_AUXADC_DAT0 +
		      chan->channel * 0x04;

	mutex_lock(&adc_dev->lock);

	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
			      0, 1 << chan->channel);

	/* read channel and make sure old ready bit == 0 */
	ret = readl_poll_timeout(reg_channel, val,
				 ((val & MT6577_AUXADC_RDY0) == 0),
				 MT6577_AUXADC_SLEEP_US,
				 MT6577_AUXADC_TIMEOUT_US);
	if (ret < 0) {
		dev_err(indio_dev->dev.parent,
			"wait for channel[%d] ready bit clear time out\n",
			chan->channel);
		goto err_timeout;
	}

	/* set bit to trigger sample */
	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
			      1 << chan->channel, 0);

	/* we must delay here for hardware sample channel data */
	udelay(MT6577_AUXADC_SAMPLE_READY_US);

	/* check MTK_AUXADC_CON2 if auxadc is idle */
	ret = readl_poll_timeout(adc_dev->reg_base + MT6577_AUXADC_CON2, val,
				 ((val & MT6577_AUXADC_STA) == 0),
				 MT6577_AUXADC_SLEEP_US,
				 MT6577_AUXADC_TIMEOUT_US);
	if (ret < 0) {
		dev_err(indio_dev->dev.parent,
			"wait for auxadc idle time out\n");
		goto err_timeout;
	}

	/* read channel and make sure ready bit == 1 */
	ret = readl_poll_timeout(reg_channel, val,
				 ((val & MT6577_AUXADC_RDY0) != 0),
				 MT6577_AUXADC_SLEEP_US,
				 MT6577_AUXADC_TIMEOUT_US);
	if (ret < 0) {
		dev_err(indio_dev->dev.parent,
			"wait for channel[%d] data ready time out\n",
			chan->channel);
		goto err_timeout;
	}

	/* read data */
	val = readl(reg_channel) & MT6577_AUXADC_DAT_MASK;

	mutex_unlock(&adc_dev->lock);

	return val;

err_timeout:

	mutex_unlock(&adc_dev->lock);

	return -ETIMEDOUT;
}

static int mt6577_auxadc_read_raw(struct iio_dev *indio_dev,
				  struct iio_chan_spec const *chan,
				  int *val,
				  int *val2,
				  long info)
{
	switch (info) {
	case IIO_CHAN_INFO_PROCESSED:
		*val = mt6577_auxadc_read(indio_dev, chan);
		if (*val < 0) {
			dev_err(indio_dev->dev.parent,
				"failed to sample data on channel[%d]\n",
				chan->channel);
			return *val;
		}
		return IIO_VAL_INT;

	default:
		return -EINVAL;
	}
}

static const struct iio_info mt6577_auxadc_info = {
	.driver_module = THIS_MODULE,
	.read_raw = &mt6577_auxadc_read_raw,
};

static int __maybe_unused mt6577_auxadc_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);
	int ret;

	ret = clk_prepare_enable(adc_dev->adc_clk);
	if (ret) {
		pr_err("failed to enable auxadc clock\n");
		return ret;
	}

	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
			      MT6577_AUXADC_PDN_EN, 0);
	mdelay(MT6577_AUXADC_POWER_READY_MS);

	return 0;
}

static int __maybe_unused mt6577_auxadc_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);

	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
			      0, MT6577_AUXADC_PDN_EN);
	clk_disable_unprepare(adc_dev->adc_clk);

	return 0;
}

static int mt6577_auxadc_probe(struct platform_device *pdev)
{
	struct mt6577_auxadc_device *adc_dev;
	unsigned long adc_clk_rate;
	struct resource *res;
	struct iio_dev *indio_dev;
	int ret;

	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
	if (!indio_dev)
		return -ENOMEM;

	adc_dev = iio_priv(indio_dev);
	indio_dev->dev.parent = &pdev->dev;
	indio_dev->name = dev_name(&pdev->dev);
	indio_dev->info = &mt6577_auxadc_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = mt6577_auxadc_iio_channels;
	indio_dev->num_channels = ARRAY_SIZE(mt6577_auxadc_iio_channels);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(adc_dev->reg_base)) {
		dev_err(&pdev->dev, "failed to get auxadc base address\n");
		return PTR_ERR(adc_dev->reg_base);
	}

	adc_dev->adc_clk = devm_clk_get(&pdev->dev, "main");
	if (IS_ERR(adc_dev->adc_clk)) {
		dev_err(&pdev->dev, "failed to get auxadc clock\n");
		return PTR_ERR(adc_dev->adc_clk);
	}

	ret = clk_prepare_enable(adc_dev->adc_clk);
	if (ret) {
		dev_err(&pdev->dev, "failed to enable auxadc clock\n");
		return ret;
	}

	adc_clk_rate = clk_get_rate(adc_dev->adc_clk);
	if (!adc_clk_rate) {
		ret = -EINVAL;
		dev_err(&pdev->dev, "null clock rate\n");
		goto err_disable_clk;
	}

	mutex_init(&adc_dev->lock);

	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
			      MT6577_AUXADC_PDN_EN, 0);
	mdelay(MT6577_AUXADC_POWER_READY_MS);

	platform_set_drvdata(pdev, indio_dev);

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to register iio device\n");
		goto err_power_off;
	}

	return 0;

err_power_off:
	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
			      0, MT6577_AUXADC_PDN_EN);
err_disable_clk:
	clk_disable_unprepare(adc_dev->adc_clk);
	return ret;
}

static int mt6577_auxadc_remove(struct platform_device *pdev)
{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
			      0, MT6577_AUXADC_PDN_EN);

	clk_disable_unprepare(adc_dev->adc_clk);

	return 0;
}

static SIMPLE_DEV_PM_OPS(mt6577_auxadc_pm_ops,
			 mt6577_auxadc_suspend,
			 mt6577_auxadc_resume);

static const struct of_device_id mt6577_auxadc_of_match[] = {
	{ .compatible = "mediatek,mt2701-auxadc", },
	{ .compatible = "mediatek,mt7622-auxadc", },
	{ .compatible = "mediatek,mt8173-auxadc", },
	{ }
};
MODULE_DEVICE_TABLE(of, mt6577_auxadc_of_match);

static struct platform_driver mt6577_auxadc_driver = {
	.driver = {
		.name   = "mt6577-auxadc",
		.of_match_table = mt6577_auxadc_of_match,
		.pm = &mt6577_auxadc_pm_ops,
	},
	.probe	= mt6577_auxadc_probe,
	.remove	= mt6577_auxadc_remove,
};
module_platform_driver(mt6577_auxadc_driver);

MODULE_AUTHOR("Zhiyong Tao <zhiyong.tao@mediatek.com>");
MODULE_DESCRIPTION("MTK AUXADC Device Driver");
MODULE_LICENSE("GPL v2");
OpenPOWER on IntegriCloud