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