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 
30 enum vf610_conversion_mode_sel {
31 	VF610_DAC_CONV_HIGH_POWER,
32 	VF610_DAC_CONV_LOW_POWER,
33 };
34 
35 struct 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 
vf610_dac_init(struct vf610_dac * info)43 static 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 
vf610_dac_exit(struct vf610_dac * info)53 static 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 
vf610_set_conversion_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int mode)62 static 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 
vf610_get_conversion_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)82 static 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 
90 static const char * const vf610_conv_modes[] = { "high-power", "low-power" };
91 
92 static 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 
99 static 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 
113 static const struct iio_chan_spec vf610_dac_iio_channels[] = {
114 	VF610_DAC_CHAN(IIO_VOLTAGE),
115 };
116 
vf610_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)117 static 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 
vf610_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)143 static 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 
162 static const struct iio_info vf610_dac_iio_info = {
163 	.read_raw = &vf610_read_raw,
164 	.write_raw = &vf610_write_raw,
165 };
166 
167 static const struct of_device_id vf610_dac_match[] = {
168 	{ .compatible = "fsl,vf610-dac", },
169 	{ /* sentinel */ }
170 };
171 MODULE_DEVICE_TABLE(of, vf610_dac_match);
172 
vf610_dac_probe(struct platform_device * pdev)173 static 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 		dev_err(&pdev->dev, "Failed allocating iio device\n");
183 		return -ENOMEM;
184 	}
185 
186 	info = iio_priv(indio_dev);
187 	info->dev = &pdev->dev;
188 
189 	info->regs = devm_platform_ioremap_resource(pdev, 0);
190 	if (IS_ERR(info->regs))
191 		return PTR_ERR(info->regs);
192 
193 	info->clk = devm_clk_get(&pdev->dev, "dac");
194 	if (IS_ERR(info->clk)) {
195 		dev_err(&pdev->dev, "Failed getting clock, err = %ld\n",
196 			PTR_ERR(info->clk));
197 		return PTR_ERR(info->clk);
198 	}
199 
200 	platform_set_drvdata(pdev, indio_dev);
201 
202 	indio_dev->name = dev_name(&pdev->dev);
203 	indio_dev->info = &vf610_dac_iio_info;
204 	indio_dev->modes = INDIO_DIRECT_MODE;
205 	indio_dev->channels = vf610_dac_iio_channels;
206 	indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels);
207 
208 	mutex_init(&info->lock);
209 
210 	ret = clk_prepare_enable(info->clk);
211 	if (ret) {
212 		dev_err(&pdev->dev,
213 			"Could not prepare or enable the clock\n");
214 		return ret;
215 	}
216 
217 	vf610_dac_init(info);
218 
219 	ret = iio_device_register(indio_dev);
220 	if (ret) {
221 		dev_err(&pdev->dev, "Couldn't register the device\n");
222 		goto error_iio_device_register;
223 	}
224 
225 	return 0;
226 
227 error_iio_device_register:
228 	vf610_dac_exit(info);
229 	clk_disable_unprepare(info->clk);
230 
231 	return ret;
232 }
233 
vf610_dac_remove(struct platform_device * pdev)234 static int vf610_dac_remove(struct platform_device *pdev)
235 {
236 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
237 	struct vf610_dac *info = iio_priv(indio_dev);
238 
239 	iio_device_unregister(indio_dev);
240 	vf610_dac_exit(info);
241 	clk_disable_unprepare(info->clk);
242 
243 	return 0;
244 }
245 
vf610_dac_suspend(struct device * dev)246 static int vf610_dac_suspend(struct device *dev)
247 {
248 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
249 	struct vf610_dac *info = iio_priv(indio_dev);
250 
251 	vf610_dac_exit(info);
252 	clk_disable_unprepare(info->clk);
253 
254 	return 0;
255 }
256 
vf610_dac_resume(struct device * dev)257 static int vf610_dac_resume(struct device *dev)
258 {
259 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
260 	struct vf610_dac *info = iio_priv(indio_dev);
261 	int ret;
262 
263 	ret = clk_prepare_enable(info->clk);
264 	if (ret)
265 		return ret;
266 
267 	vf610_dac_init(info);
268 
269 	return 0;
270 }
271 
272 static DEFINE_SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend,
273 				vf610_dac_resume);
274 
275 static struct platform_driver vf610_dac_driver = {
276 	.probe          = vf610_dac_probe,
277 	.remove         = vf610_dac_remove,
278 	.driver         = {
279 		.name   = "vf610-dac",
280 		.of_match_table = vf610_dac_match,
281 		.pm     = pm_sleep_ptr(&vf610_dac_pm_ops),
282 	},
283 };
284 module_platform_driver(vf610_dac_driver);
285 
286 MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>");
287 MODULE_DESCRIPTION("Freescale VF610 DAC driver");
288 MODULE_LICENSE("GPL v2");
289