summaryrefslogtreecommitdiff
path: root/drivers/iio/dac/vf610_dac.c
blob: 5dccdd16cab367432086b100984e134598c7fb57 (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
/*
 * Freescale Vybrid vf610 DAC driver
 *
 * Copyright 2016 Toradex AG
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#define VF610_DACx_STATCTRL		0x20

#define VF610_DAC_DACEN			BIT(15)
#define VF610_DAC_DACRFS		BIT(14)
#define VF610_DAC_LPEN			BIT(11)

#define VF610_DAC_DAT0(x)		((x) & 0xFFF)

enum vf610_conversion_mode_sel {
	VF610_DAC_CONV_HIGH_POWER,
	VF610_DAC_CONV_LOW_POWER,
};

struct vf610_dac {
	struct clk *clk;
	struct device *dev;
	enum vf610_conversion_mode_sel conv_mode;
	void __iomem *regs;
};

static void vf610_dac_init(struct vf610_dac *info)
{
	int val;

	info->conv_mode = VF610_DAC_CONV_LOW_POWER;
	val = VF610_DAC_DACEN | VF610_DAC_DACRFS |
		VF610_DAC_LPEN;
	writel(val, info->regs + VF610_DACx_STATCTRL);
}

static void vf610_dac_exit(struct vf610_dac *info)
{
	int val;

	val = readl(info->regs + VF610_DACx_STATCTRL);
	val &= ~VF610_DAC_DACEN;
	writel(val, info->regs + VF610_DACx_STATCTRL);
}

static int vf610_set_conversion_mode(struct iio_dev *indio_dev,
				const struct iio_chan_spec *chan,
				unsigned int mode)
{
	struct vf610_dac *info = iio_priv(indio_dev);
	int val;

	mutex_lock(&indio_dev->mlock);
	info->conv_mode = mode;
	val = readl(info->regs + VF610_DACx_STATCTRL);
	if (mode)
		val |= VF610_DAC_LPEN;
	else
		val &= ~VF610_DAC_LPEN;
	writel(val, info->regs + VF610_DACx_STATCTRL);
	mutex_unlock(&indio_dev->mlock);

	return 0;
}

static int vf610_get_conversion_mode(struct iio_dev *indio_dev,
				const struct iio_chan_spec *chan)
{
	struct vf610_dac *info = iio_priv(indio_dev);

	return info->conv_mode;
}

static const char * const vf610_conv_modes[] = { "high-power", "low-power" };

static const struct iio_enum vf610_conversion_mode = {
	.items = vf610_conv_modes,
	.num_items = ARRAY_SIZE(vf610_conv_modes),
	.get = vf610_get_conversion_mode,
	.set = vf610_set_conversion_mode,
};

static const struct iio_chan_spec_ext_info vf610_ext_info[] = {
	IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR,
		&vf610_conversion_mode),
	{},
};

#define VF610_DAC_CHAN(_chan_type) { \
	.type = (_chan_type), \
	.output = 1, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	.ext_info = vf610_ext_info, \
}

static const struct iio_chan_spec vf610_dac_iio_channels[] = {
	VF610_DAC_CHAN(IIO_VOLTAGE),
};

static int vf610_read_raw(struct iio_dev *indio_dev,
			struct iio_chan_spec const *chan,
			int *val, int *val2,
			long mask)
{
	struct vf610_dac *info = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		*val = VF610_DAC_DAT0(readl(info->regs));
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		/*
		 * DACRFS is always 1 for valid reference and typical
		 * reference voltage as per Vybrid datasheet is 3.3V
		 * from section 9.1.2.1 of Vybrid datasheet
		 */
		*val = 3300 /* mV */;
		*val2 = 12;
		return IIO_VAL_FRACTIONAL_LOG2;

	default:
		return -EINVAL;
	}
}

static int vf610_write_raw(struct iio_dev *indio_dev,
			struct iio_chan_spec const *chan,
			int val, int val2,
			long mask)
{
	struct vf610_dac *info = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&indio_dev->mlock);
		writel(VF610_DAC_DAT0(val), info->regs);
		mutex_unlock(&indio_dev->mlock);
		return 0;

	default:
		return -EINVAL;
	}
}

static const struct iio_info vf610_dac_iio_info = {
	.read_raw = &vf610_read_raw,
	.write_raw = &vf610_write_raw,
};

static const struct of_device_id vf610_dac_match[] = {
	{ .compatible = "fsl,vf610-dac", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, vf610_dac_match);

static int vf610_dac_probe(struct platform_device *pdev)
{
	struct iio_dev *indio_dev;
	struct vf610_dac *info;
	struct resource *mem;
	int ret;

	indio_dev = devm_iio_device_alloc(&pdev->dev,
					sizeof(struct vf610_dac));
	if (!indio_dev) {
		dev_err(&pdev->dev, "Failed allocating iio device\n");
		return -ENOMEM;
	}

	info = iio_priv(indio_dev);
	info->dev = &pdev->dev;

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	info->regs = devm_ioremap_resource(&pdev->dev, mem);
	if (IS_ERR(info->regs))
		return PTR_ERR(info->regs);

	info->clk = devm_clk_get(&pdev->dev, "dac");
	if (IS_ERR(info->clk)) {
		dev_err(&pdev->dev, "Failed getting clock, err = %ld\n",
			PTR_ERR(info->clk));
		return PTR_ERR(info->clk);
	}

	platform_set_drvdata(pdev, indio_dev);

	indio_dev->name = dev_name(&pdev->dev);
	indio_dev->dev.parent = &pdev->dev;
	indio_dev->dev.of_node = pdev->dev.of_node;
	indio_dev->info = &vf610_dac_iio_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = vf610_dac_iio_channels;
	indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels);

	ret = clk_prepare_enable(info->clk);
	if (ret) {
		dev_err(&pdev->dev,
			"Could not prepare or enable the clock\n");
		return ret;
	}

	vf610_dac_init(info);

	ret = iio_device_register(indio_dev);
	if (ret) {
		dev_err(&pdev->dev, "Couldn't register the device\n");
		goto error_iio_device_register;
	}

	return 0;

error_iio_device_register:
	clk_disable_unprepare(info->clk);

	return ret;
}

static int vf610_dac_remove(struct platform_device *pdev)
{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct vf610_dac *info = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	vf610_dac_exit(info);
	clk_disable_unprepare(info->clk);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int vf610_dac_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct vf610_dac *info = iio_priv(indio_dev);

	vf610_dac_exit(info);
	clk_disable_unprepare(info->clk);

	return 0;
}

static int vf610_dac_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct vf610_dac *info = iio_priv(indio_dev);
	int ret;

	ret = clk_prepare_enable(info->clk);
	if (ret)
		return ret;

	vf610_dac_init(info);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend, vf610_dac_resume);

static struct platform_driver vf610_dac_driver = {
	.probe          = vf610_dac_probe,
	.remove         = vf610_dac_remove,
	.driver         = {
		.name   = "vf610-dac",
		.of_match_table = vf610_dac_match,
		.pm     = &vf610_dac_pm_ops,
	},
};
module_platform_driver(vf610_dac_driver);

MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>");
MODULE_DESCRIPTION("Freescale VF610 DAC driver");
MODULE_LICENSE("GPL v2");