1 /*
2 * Marvell Berlin2 ADC driver
3 *
4 * Copyright (C) 2015 Marvell Technology Group Ltd.
5 *
6 * Antoine Tenart <antoine.tenart@free-electrons.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13 #include <linux/iio/iio.h>
14 #include <linux/iio/driver.h>
15 #include <linux/iio/machine.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
21 #include <linux/mfd/syscon.h>
22 #include <linux/regmap.h>
23 #include <linux/sched.h>
24 #include <linux/wait.h>
25
26 #define BERLIN2_SM_CTRL 0x14
27 #define BERLIN2_SM_CTRL_SM_SOC_INT BIT(1)
28 #define BERLIN2_SM_CTRL_SOC_SM_INT BIT(2)
29 #define BERLIN2_SM_CTRL_ADC_SEL(x) ((x) << 5) /* 0-15 */
30 #define BERLIN2_SM_CTRL_ADC_SEL_MASK GENMASK(8, 5)
31 #define BERLIN2_SM_CTRL_ADC_POWER BIT(9)
32 #define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2 (0x0 << 10)
33 #define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3 (0x1 << 10)
34 #define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4 (0x2 << 10)
35 #define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8 (0x3 << 10)
36 #define BERLIN2_SM_CTRL_ADC_CLKSEL_MASK GENMASK(11, 10)
37 #define BERLIN2_SM_CTRL_ADC_START BIT(12)
38 #define BERLIN2_SM_CTRL_ADC_RESET BIT(13)
39 #define BERLIN2_SM_CTRL_ADC_BANDGAP_RDY BIT(14)
40 #define BERLIN2_SM_CTRL_ADC_CONT_SINGLE (0x0 << 15)
41 #define BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS (0x1 << 15)
42 #define BERLIN2_SM_CTRL_ADC_BUFFER_EN BIT(16)
43 #define BERLIN2_SM_CTRL_ADC_VREF_EXT (0x0 << 17)
44 #define BERLIN2_SM_CTRL_ADC_VREF_INT (0x1 << 17)
45 #define BERLIN2_SM_CTRL_ADC_ROTATE BIT(19)
46 #define BERLIN2_SM_CTRL_TSEN_EN BIT(20)
47 #define BERLIN2_SM_CTRL_TSEN_CLK_SEL_125 (0x0 << 21) /* 1.25 MHz */
48 #define BERLIN2_SM_CTRL_TSEN_CLK_SEL_250 (0x1 << 21) /* 2.5 MHz */
49 #define BERLIN2_SM_CTRL_TSEN_MODE_0_125 (0x0 << 22) /* 0-125 C */
50 #define BERLIN2_SM_CTRL_TSEN_MODE_10_50 (0x1 << 22) /* 10-50 C */
51 #define BERLIN2_SM_CTRL_TSEN_RESET BIT(29)
52 #define BERLIN2_SM_ADC_DATA 0x20
53 #define BERLIN2_SM_ADC_MASK GENMASK(9, 0)
54 #define BERLIN2_SM_ADC_STATUS 0x1c
55 #define BERLIN2_SM_ADC_STATUS_DATA_RDY(x) BIT(x) /* 0-15 */
56 #define BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK GENMASK(15, 0)
57 #define BERLIN2_SM_ADC_STATUS_INT_EN(x) (BIT(x) << 16) /* 0-15 */
58 #define BERLIN2_SM_ADC_STATUS_INT_EN_MASK GENMASK(31, 16)
59 #define BERLIN2_SM_TSEN_STATUS 0x24
60 #define BERLIN2_SM_TSEN_STATUS_DATA_RDY BIT(0)
61 #define BERLIN2_SM_TSEN_STATUS_INT_EN BIT(1)
62 #define BERLIN2_SM_TSEN_DATA 0x28
63 #define BERLIN2_SM_TSEN_MASK GENMASK(9, 0)
64 #define BERLIN2_SM_TSEN_CTRL 0x74
65 #define BERLIN2_SM_TSEN_CTRL_START BIT(8)
66 #define BERLIN2_SM_TSEN_CTRL_SETTLING_4 (0x0 << 21) /* 4 us */
67 #define BERLIN2_SM_TSEN_CTRL_SETTLING_12 (0x1 << 21) /* 12 us */
68 #define BERLIN2_SM_TSEN_CTRL_SETTLING_MASK BIT(21)
69 #define BERLIN2_SM_TSEN_CTRL_TRIM(x) ((x) << 22)
70 #define BERLIN2_SM_TSEN_CTRL_TRIM_MASK GENMASK(25, 22)
71
72 struct berlin2_adc_priv {
73 struct regmap *regmap;
74 struct mutex lock;
75 wait_queue_head_t wq;
76 bool data_available;
77 int data;
78 };
79
80 #define BERLIN2_ADC_CHANNEL(n, t) \
81 { \
82 .channel = n, \
83 .datasheet_name = "channel"#n, \
84 .type = t, \
85 .indexed = 1, \
86 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
87 }
88
89 static const struct iio_chan_spec berlin2_adc_channels[] = {
90 BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE), /* external input */
91 BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE), /* external input */
92 BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE), /* external input */
93 BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE), /* external input */
94 BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE), /* reserved */
95 BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE), /* reserved */
96 { /* temperature sensor */
97 .channel = 6,
98 .datasheet_name = "channel6",
99 .type = IIO_TEMP,
100 .indexed = 0,
101 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
102 },
103 BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE), /* reserved */
104 IIO_CHAN_SOFT_TIMESTAMP(8), /* timestamp */
105 };
106
berlin2_adc_read(struct iio_dev * indio_dev,int channel)107 static int berlin2_adc_read(struct iio_dev *indio_dev, int channel)
108 {
109 struct berlin2_adc_priv *priv = iio_priv(indio_dev);
110 int data, ret;
111
112 mutex_lock(&priv->lock);
113
114 /* Enable the interrupts */
115 regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS,
116 BERLIN2_SM_ADC_STATUS_INT_EN(channel));
117
118 /* Configure the ADC */
119 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
120 BERLIN2_SM_CTRL_ADC_RESET |
121 BERLIN2_SM_CTRL_ADC_SEL_MASK |
122 BERLIN2_SM_CTRL_ADC_START,
123 BERLIN2_SM_CTRL_ADC_SEL(channel) |
124 BERLIN2_SM_CTRL_ADC_START);
125
126 ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
127 msecs_to_jiffies(1000));
128
129 /* Disable the interrupts */
130 regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS,
131 BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0);
132
133 if (ret == 0)
134 ret = -ETIMEDOUT;
135 if (ret < 0) {
136 mutex_unlock(&priv->lock);
137 return ret;
138 }
139
140 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
141 BERLIN2_SM_CTRL_ADC_START, 0);
142
143 data = priv->data;
144 priv->data_available = false;
145
146 mutex_unlock(&priv->lock);
147
148 return data;
149 }
150
berlin2_adc_tsen_read(struct iio_dev * indio_dev)151 static int berlin2_adc_tsen_read(struct iio_dev *indio_dev)
152 {
153 struct berlin2_adc_priv *priv = iio_priv(indio_dev);
154 int data, ret;
155
156 mutex_lock(&priv->lock);
157
158 /* Enable interrupts */
159 regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS,
160 BERLIN2_SM_TSEN_STATUS_INT_EN);
161
162 /* Configure the ADC */
163 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
164 BERLIN2_SM_CTRL_TSEN_RESET |
165 BERLIN2_SM_CTRL_ADC_ROTATE,
166 BERLIN2_SM_CTRL_ADC_ROTATE);
167
168 /* Configure the temperature sensor */
169 regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
170 BERLIN2_SM_TSEN_CTRL_TRIM_MASK |
171 BERLIN2_SM_TSEN_CTRL_SETTLING_MASK |
172 BERLIN2_SM_TSEN_CTRL_START,
173 BERLIN2_SM_TSEN_CTRL_TRIM(3) |
174 BERLIN2_SM_TSEN_CTRL_SETTLING_12 |
175 BERLIN2_SM_TSEN_CTRL_START);
176
177 ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
178 msecs_to_jiffies(1000));
179
180 /* Disable interrupts */
181 regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS,
182 BERLIN2_SM_TSEN_STATUS_INT_EN, 0);
183
184 if (ret == 0)
185 ret = -ETIMEDOUT;
186 if (ret < 0) {
187 mutex_unlock(&priv->lock);
188 return ret;
189 }
190
191 regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
192 BERLIN2_SM_TSEN_CTRL_START, 0);
193
194 data = priv->data;
195 priv->data_available = false;
196
197 mutex_unlock(&priv->lock);
198
199 return data;
200 }
201
berlin2_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)202 static int berlin2_adc_read_raw(struct iio_dev *indio_dev,
203 struct iio_chan_spec const *chan, int *val,
204 int *val2, long mask)
205 {
206 int temp;
207
208 switch (mask) {
209 case IIO_CHAN_INFO_RAW:
210 if (chan->type != IIO_VOLTAGE)
211 return -EINVAL;
212
213 *val = berlin2_adc_read(indio_dev, chan->channel);
214 if (*val < 0)
215 return *val;
216
217 return IIO_VAL_INT;
218 case IIO_CHAN_INFO_PROCESSED:
219 if (chan->type != IIO_TEMP)
220 return -EINVAL;
221
222 temp = berlin2_adc_tsen_read(indio_dev);
223 if (temp < 0)
224 return temp;
225
226 if (temp > 2047)
227 temp -= 4096;
228
229 /* Convert to milli Celsius */
230 *val = ((temp * 100000) / 264 - 270000);
231 return IIO_VAL_INT;
232 default:
233 break;
234 }
235
236 return -EINVAL;
237 }
238
berlin2_adc_irq(int irq,void * private)239 static irqreturn_t berlin2_adc_irq(int irq, void *private)
240 {
241 struct berlin2_adc_priv *priv = iio_priv(private);
242 unsigned val;
243
244 regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val);
245 if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) {
246 regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data);
247 priv->data &= BERLIN2_SM_ADC_MASK;
248
249 val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK;
250 regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val);
251
252 priv->data_available = true;
253 wake_up_interruptible(&priv->wq);
254 }
255
256 return IRQ_HANDLED;
257 }
258
berlin2_adc_tsen_irq(int irq,void * private)259 static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private)
260 {
261 struct berlin2_adc_priv *priv = iio_priv(private);
262 unsigned val;
263
264 regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val);
265 if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) {
266 regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data);
267 priv->data &= BERLIN2_SM_TSEN_MASK;
268
269 val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY;
270 regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val);
271
272 priv->data_available = true;
273 wake_up_interruptible(&priv->wq);
274 }
275
276 return IRQ_HANDLED;
277 }
278
279 static const struct iio_info berlin2_adc_info = {
280 .read_raw = berlin2_adc_read_raw,
281 };
282
berlin2_adc_probe(struct platform_device * pdev)283 static int berlin2_adc_probe(struct platform_device *pdev)
284 {
285 struct iio_dev *indio_dev;
286 struct berlin2_adc_priv *priv;
287 struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
288 int irq, tsen_irq;
289 int ret;
290
291 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
292 if (!indio_dev) {
293 of_node_put(parent_np);
294 return -ENOMEM;
295 }
296
297 priv = iio_priv(indio_dev);
298 platform_set_drvdata(pdev, indio_dev);
299
300 priv->regmap = syscon_node_to_regmap(parent_np);
301 of_node_put(parent_np);
302 if (IS_ERR(priv->regmap))
303 return PTR_ERR(priv->regmap);
304
305 irq = platform_get_irq_byname(pdev, "adc");
306 if (irq < 0)
307 return irq;
308
309 tsen_irq = platform_get_irq_byname(pdev, "tsen");
310 if (tsen_irq < 0)
311 return tsen_irq;
312
313 ret = devm_request_irq(&pdev->dev, irq, berlin2_adc_irq, 0,
314 pdev->dev.driver->name, indio_dev);
315 if (ret)
316 return ret;
317
318 ret = devm_request_irq(&pdev->dev, tsen_irq, berlin2_adc_tsen_irq,
319 0, pdev->dev.driver->name, indio_dev);
320 if (ret)
321 return ret;
322
323 init_waitqueue_head(&priv->wq);
324 mutex_init(&priv->lock);
325
326 indio_dev->name = dev_name(&pdev->dev);
327 indio_dev->modes = INDIO_DIRECT_MODE;
328 indio_dev->info = &berlin2_adc_info;
329
330 indio_dev->channels = berlin2_adc_channels;
331 indio_dev->num_channels = ARRAY_SIZE(berlin2_adc_channels);
332
333 /* Power up the ADC */
334 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
335 BERLIN2_SM_CTRL_ADC_POWER,
336 BERLIN2_SM_CTRL_ADC_POWER);
337
338 ret = iio_device_register(indio_dev);
339 if (ret) {
340 /* Power down the ADC */
341 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
342 BERLIN2_SM_CTRL_ADC_POWER, 0);
343 return ret;
344 }
345
346 return 0;
347 }
348
berlin2_adc_remove(struct platform_device * pdev)349 static int berlin2_adc_remove(struct platform_device *pdev)
350 {
351 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
352 struct berlin2_adc_priv *priv = iio_priv(indio_dev);
353
354 iio_device_unregister(indio_dev);
355
356 /* Power down the ADC */
357 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
358 BERLIN2_SM_CTRL_ADC_POWER, 0);
359
360 return 0;
361 }
362
363 static const struct of_device_id berlin2_adc_match[] = {
364 { .compatible = "marvell,berlin2-adc", },
365 { },
366 };
367 MODULE_DEVICE_TABLE(of, berlin2_adc_match);
368
369 static struct platform_driver berlin2_adc_driver = {
370 .driver = {
371 .name = "berlin2-adc",
372 .of_match_table = berlin2_adc_match,
373 },
374 .probe = berlin2_adc_probe,
375 .remove = berlin2_adc_remove,
376 };
377 module_platform_driver(berlin2_adc_driver);
378
379 MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
380 MODULE_DESCRIPTION("Marvell Berlin2 ADC driver");
381 MODULE_LICENSE("GPL v2");
382