vf610_dac.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Freescale Vybrid vf610 DAC driver
  4 *
  5 * Copyright 2016 Toradex AG
  6 */
  7
  8#include <linux/clk.h>
  9#include <linux/err.h>
 10#include <linux/interrupt.h>
 11#include <linux/io.h>
 12#include <linux/kernel.h>
 13#include <linux/mod_devicetable.h>
 14#include <linux/module.h>
 15#include <linux/platform_device.h>
 16#include <linux/regulator/consumer.h>
 17#include <linux/slab.h>
 18
 19#include <linux/iio/iio.h>
 20#include <linux/iio/sysfs.h>
 21
 22#define VF610_DACx_STATCTRL		0x20
 23
 24#define VF610_DAC_DACEN			BIT(15)
 25#define VF610_DAC_DACRFS		BIT(14)
 26#define VF610_DAC_LPEN			BIT(11)
 27
 28#define VF610_DAC_DAT0(x)		((x) & 0xFFF)
 29
 30enum vf610_conversion_mode_sel {
 31	VF610_DAC_CONV_HIGH_POWER,
 32	VF610_DAC_CONV_LOW_POWER,
 33};
 34
 35struct vf610_dac {
 36	struct clk *clk;
 37	struct device *dev;
 38	enum vf610_conversion_mode_sel conv_mode;
 39	void __iomem *regs;
 40	struct mutex lock;
 41};
 42
 43static void vf610_dac_init(struct vf610_dac *info)
 44{
 45	int val;
 46
 47	info->conv_mode = VF610_DAC_CONV_LOW_POWER;
 48	val = VF610_DAC_DACEN | VF610_DAC_DACRFS |
 49		VF610_DAC_LPEN;
 50	writel(val, info->regs + VF610_DACx_STATCTRL);
 51}
 52
 53static void vf610_dac_exit(struct vf610_dac *info)
 54{
 55	int val;
 56
 57	val = readl(info->regs + VF610_DACx_STATCTRL);
 58	val &= ~VF610_DAC_DACEN;
 59	writel(val, info->regs + VF610_DACx_STATCTRL);
 60}
 61
 62static int vf610_set_conversion_mode(struct iio_dev *indio_dev,
 63				const struct iio_chan_spec *chan,
 64				unsigned int mode)
 65{
 66	struct vf610_dac *info = iio_priv(indio_dev);
 67	int val;
 68
 69	mutex_lock(&info->lock);
 70	info->conv_mode = mode;
 71	val = readl(info->regs + VF610_DACx_STATCTRL);
 72	if (mode)
 73		val |= VF610_DAC_LPEN;
 74	else
 75		val &= ~VF610_DAC_LPEN;
 76	writel(val, info->regs + VF610_DACx_STATCTRL);
 77	mutex_unlock(&info->lock);
 78
 79	return 0;
 80}
 81
 82static int vf610_get_conversion_mode(struct iio_dev *indio_dev,
 83				const struct iio_chan_spec *chan)
 84{
 85	struct vf610_dac *info = iio_priv(indio_dev);
 86
 87	return info->conv_mode;
 88}
 89
 90static const char * const vf610_conv_modes[] = { "high-power", "low-power" };
 91
 92static const struct iio_enum vf610_conversion_mode = {
 93	.items = vf610_conv_modes,
 94	.num_items = ARRAY_SIZE(vf610_conv_modes),
 95	.get = vf610_get_conversion_mode,
 96	.set = vf610_set_conversion_mode,
 97};
 98
 99static const struct iio_chan_spec_ext_info vf610_ext_info[] = {
100	IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR,
101		&vf610_conversion_mode),
102	{ }
103};
104
105#define VF610_DAC_CHAN(_chan_type) { \
106	.type = (_chan_type), \
107	.output = 1, \
108	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
109	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
110	.ext_info = vf610_ext_info, \
111}
112
113static const struct iio_chan_spec vf610_dac_iio_channels[] = {
114	VF610_DAC_CHAN(IIO_VOLTAGE),
115};
116
117static int vf610_read_raw(struct iio_dev *indio_dev,
118			struct iio_chan_spec const *chan,
119			int *val, int *val2,
120			long mask)
121{
122	struct vf610_dac *info = iio_priv(indio_dev);
123
124	switch (mask) {
125	case IIO_CHAN_INFO_RAW:
126		*val = VF610_DAC_DAT0(readl(info->regs));
127		return IIO_VAL_INT;
128	case IIO_CHAN_INFO_SCALE:
129		/*
130		 * DACRFS is always 1 for valid reference and typical
131		 * reference voltage as per Vybrid datasheet is 3.3V
132		 * from section 9.1.2.1 of Vybrid datasheet
133		 */
134		*val = 3300 /* mV */;
135		*val2 = 12;
136		return IIO_VAL_FRACTIONAL_LOG2;
137
138	default:
139		return -EINVAL;
140	}
141}
142
143static int vf610_write_raw(struct iio_dev *indio_dev,
144			struct iio_chan_spec const *chan,
145			int val, int val2,
146			long mask)
147{
148	struct vf610_dac *info = iio_priv(indio_dev);
149
150	switch (mask) {
151	case IIO_CHAN_INFO_RAW:
152		mutex_lock(&info->lock);
153		writel(VF610_DAC_DAT0(val), info->regs);
154		mutex_unlock(&info->lock);
155		return 0;
156
157	default:
158		return -EINVAL;
159	}
160}
161
162static const struct iio_info vf610_dac_iio_info = {
163	.read_raw = &vf610_read_raw,
164	.write_raw = &vf610_write_raw,
165};
166
167static const struct of_device_id vf610_dac_match[] = {
168	{ .compatible = "fsl,vf610-dac", },
169	{ }
170};
171MODULE_DEVICE_TABLE(of, vf610_dac_match);
172
173static int vf610_dac_probe(struct platform_device *pdev)
174{
175	struct iio_dev *indio_dev;
176	struct vf610_dac *info;
177	int ret;
178
179	indio_dev = devm_iio_device_alloc(&pdev->dev,
180					sizeof(struct vf610_dac));
181	if (!indio_dev)
182		return -ENOMEM;
183
184	info = iio_priv(indio_dev);
185	info->dev = &pdev->dev;
186
187	info->regs = devm_platform_ioremap_resource(pdev, 0);
188	if (IS_ERR(info->regs))
189		return PTR_ERR(info->regs);
190
191	info->clk = devm_clk_get_enabled(&pdev->dev, "dac");
192	if (IS_ERR(info->clk))
193		return dev_err_probe(&pdev->dev, PTR_ERR(info->clk),
194				     "Failed getting clock\n");
195
196	platform_set_drvdata(pdev, indio_dev);
197
198	indio_dev->name = dev_name(&pdev->dev);
199	indio_dev->info = &vf610_dac_iio_info;
200	indio_dev->modes = INDIO_DIRECT_MODE;
201	indio_dev->channels = vf610_dac_iio_channels;
202	indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels);
203
204	mutex_init(&info->lock);
205
206	vf610_dac_init(info);
207
208	ret = iio_device_register(indio_dev);
209	if (ret) {
210		dev_err(&pdev->dev, "Couldn't register the device\n");
211		goto error_iio_device_register;
212	}
213
214	return 0;
215
216error_iio_device_register:
217	vf610_dac_exit(info);
218
219	return ret;
220}
221
222static void vf610_dac_remove(struct platform_device *pdev)
223{
224	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
225	struct vf610_dac *info = iio_priv(indio_dev);
226
227	iio_device_unregister(indio_dev);
228	vf610_dac_exit(info);
229}
230
231static int vf610_dac_suspend(struct device *dev)
232{
233	struct iio_dev *indio_dev = dev_get_drvdata(dev);
234	struct vf610_dac *info = iio_priv(indio_dev);
235
236	vf610_dac_exit(info);
237	clk_disable_unprepare(info->clk);
238
239	return 0;
240}
241
242static int vf610_dac_resume(struct device *dev)
243{
244	struct iio_dev *indio_dev = dev_get_drvdata(dev);
245	struct vf610_dac *info = iio_priv(indio_dev);
246	int ret;
247
248	ret = clk_prepare_enable(info->clk);
249	if (ret)
250		return ret;
251
252	vf610_dac_init(info);
253
254	return 0;
255}
256
257static DEFINE_SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend,
258				vf610_dac_resume);
259
260static struct platform_driver vf610_dac_driver = {
261	.probe          = vf610_dac_probe,
262	.remove         = vf610_dac_remove,
263	.driver         = {
264		.name   = "vf610-dac",
265		.of_match_table = vf610_dac_match,
266		.pm     = pm_sleep_ptr(&vf610_dac_pm_ops),
267	},
268};
269module_platform_driver(vf610_dac_driver);
270
271MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>");
272MODULE_DESCRIPTION("Freescale VF610 DAC driver");
273MODULE_LICENSE("GPL v2");