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