xref: /openbmc/linux/drivers/iio/adc/da9150-gpadc.c (revision 9cfc5c90)
1 /*
2  * DA9150 GPADC Driver
3  *
4  * Copyright (c) 2014 Dialog Semiconductor
5  *
6  * Author: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
7  *
8  * This program is free software; you can redistribute  it and/or modify it
9  * under  the terms of  the GNU General  Public License as published by the
10  * Free Software Foundation;  either version 2 of the  License, or (at your
11  * option) any later version.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/interrupt.h>
19 #include <linux/mutex.h>
20 #include <linux/completion.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/machine.h>
23 #include <linux/iio/driver.h>
24 #include <linux/mfd/da9150/core.h>
25 #include <linux/mfd/da9150/registers.h>
26 
27 /* Channels */
28 enum da9150_gpadc_hw_channel {
29 	DA9150_GPADC_HW_CHAN_GPIOA_2V = 0,
30 	DA9150_GPADC_HW_CHAN_GPIOA_2V_,
31 	DA9150_GPADC_HW_CHAN_GPIOB_2V,
32 	DA9150_GPADC_HW_CHAN_GPIOB_2V_,
33 	DA9150_GPADC_HW_CHAN_GPIOC_2V,
34 	DA9150_GPADC_HW_CHAN_GPIOC_2V_,
35 	DA9150_GPADC_HW_CHAN_GPIOD_2V,
36 	DA9150_GPADC_HW_CHAN_GPIOD_2V_,
37 	DA9150_GPADC_HW_CHAN_IBUS_SENSE,
38 	DA9150_GPADC_HW_CHAN_IBUS_SENSE_,
39 	DA9150_GPADC_HW_CHAN_VBUS_DIV,
40 	DA9150_GPADC_HW_CHAN_VBUS_DIV_,
41 	DA9150_GPADC_HW_CHAN_ID,
42 	DA9150_GPADC_HW_CHAN_ID_,
43 	DA9150_GPADC_HW_CHAN_VSYS,
44 	DA9150_GPADC_HW_CHAN_VSYS_,
45 	DA9150_GPADC_HW_CHAN_GPIOA_6V,
46 	DA9150_GPADC_HW_CHAN_GPIOA_6V_,
47 	DA9150_GPADC_HW_CHAN_GPIOB_6V,
48 	DA9150_GPADC_HW_CHAN_GPIOB_6V_,
49 	DA9150_GPADC_HW_CHAN_GPIOC_6V,
50 	DA9150_GPADC_HW_CHAN_GPIOC_6V_,
51 	DA9150_GPADC_HW_CHAN_GPIOD_6V,
52 	DA9150_GPADC_HW_CHAN_GPIOD_6V_,
53 	DA9150_GPADC_HW_CHAN_VBAT,
54 	DA9150_GPADC_HW_CHAN_VBAT_,
55 	DA9150_GPADC_HW_CHAN_TBAT,
56 	DA9150_GPADC_HW_CHAN_TBAT_,
57 	DA9150_GPADC_HW_CHAN_TJUNC_CORE,
58 	DA9150_GPADC_HW_CHAN_TJUNC_CORE_,
59 	DA9150_GPADC_HW_CHAN_TJUNC_OVP,
60 	DA9150_GPADC_HW_CHAN_TJUNC_OVP_,
61 };
62 
63 enum da9150_gpadc_channel {
64 	DA9150_GPADC_CHAN_GPIOA = 0,
65 	DA9150_GPADC_CHAN_GPIOB,
66 	DA9150_GPADC_CHAN_GPIOC,
67 	DA9150_GPADC_CHAN_GPIOD,
68 	DA9150_GPADC_CHAN_IBUS,
69 	DA9150_GPADC_CHAN_VBUS,
70 	DA9150_GPADC_CHAN_VSYS,
71 	DA9150_GPADC_CHAN_VBAT,
72 	DA9150_GPADC_CHAN_TBAT,
73 	DA9150_GPADC_CHAN_TJUNC_CORE,
74 	DA9150_GPADC_CHAN_TJUNC_OVP,
75 };
76 
77 /* Private data */
78 struct da9150_gpadc {
79 	struct da9150 *da9150;
80 	struct device *dev;
81 
82 	struct mutex lock;
83 	struct completion complete;
84 };
85 
86 
87 static irqreturn_t da9150_gpadc_irq(int irq, void *data)
88 {
89 
90 	struct da9150_gpadc *gpadc = data;
91 
92 	complete(&gpadc->complete);
93 
94 	return IRQ_HANDLED;
95 }
96 
97 static int da9150_gpadc_read_adc(struct da9150_gpadc *gpadc, int hw_chan)
98 {
99 	u8 result_regs[2];
100 	int result;
101 
102 	mutex_lock(&gpadc->lock);
103 
104 	/* Set channel & enable measurement */
105 	da9150_reg_write(gpadc->da9150, DA9150_GPADC_MAN,
106 			 (DA9150_GPADC_EN_MASK |
107 			  hw_chan << DA9150_GPADC_MUX_SHIFT));
108 
109 	/* Consume left-over completion from a previous timeout */
110 	try_wait_for_completion(&gpadc->complete);
111 
112 	/* Check for actual completion */
113 	wait_for_completion_timeout(&gpadc->complete, msecs_to_jiffies(5));
114 
115 	/* Read result and status from device */
116 	da9150_bulk_read(gpadc->da9150, DA9150_GPADC_RES_A, 2, result_regs);
117 
118 	mutex_unlock(&gpadc->lock);
119 
120 	/* Check to make sure device really has completed reading */
121 	if (result_regs[1] & DA9150_GPADC_RUN_MASK) {
122 		dev_err(gpadc->dev, "Timeout on channel %d of GPADC\n",
123 			hw_chan);
124 		return -ETIMEDOUT;
125 	}
126 
127 	/* LSBs - 2 bits */
128 	result = (result_regs[1] & DA9150_GPADC_RES_L_MASK) >>
129 		 DA9150_GPADC_RES_L_SHIFT;
130 	/* MSBs - 8 bits */
131 	result |= result_regs[0] << DA9150_GPADC_RES_L_BITS;
132 
133 	return result;
134 }
135 
136 static inline int da9150_gpadc_gpio_6v_voltage_now(int raw_val)
137 {
138 	/* Convert to mV */
139 	return (6 * ((raw_val * 1000) + 500)) / 1024;
140 }
141 
142 static inline int da9150_gpadc_ibus_current_avg(int raw_val)
143 {
144 	/* Convert to mA */
145 	return (4 * ((raw_val * 1000) + 500)) / 2048;
146 }
147 
148 static inline int da9150_gpadc_vbus_21v_voltage_now(int raw_val)
149 {
150 	/* Convert to mV */
151 	return (21 * ((raw_val * 1000) + 500)) / 1024;
152 }
153 
154 static inline int da9150_gpadc_vsys_6v_voltage_now(int raw_val)
155 {
156 	/* Convert to mV */
157 	return (3 * ((raw_val * 1000) + 500)) / 512;
158 }
159 
160 static int da9150_gpadc_read_processed(struct da9150_gpadc *gpadc, int channel,
161 				       int hw_chan, int *val)
162 {
163 	int raw_val;
164 
165 	raw_val = da9150_gpadc_read_adc(gpadc, hw_chan);
166 	if (raw_val < 0)
167 		return raw_val;
168 
169 	switch (channel) {
170 	case DA9150_GPADC_CHAN_GPIOA:
171 	case DA9150_GPADC_CHAN_GPIOB:
172 	case DA9150_GPADC_CHAN_GPIOC:
173 	case DA9150_GPADC_CHAN_GPIOD:
174 		*val = da9150_gpadc_gpio_6v_voltage_now(raw_val);
175 		break;
176 	case DA9150_GPADC_CHAN_IBUS:
177 		*val = da9150_gpadc_ibus_current_avg(raw_val);
178 		break;
179 	case DA9150_GPADC_CHAN_VBUS:
180 		*val = da9150_gpadc_vbus_21v_voltage_now(raw_val);
181 		break;
182 	case DA9150_GPADC_CHAN_VSYS:
183 		*val = da9150_gpadc_vsys_6v_voltage_now(raw_val);
184 		break;
185 	default:
186 		/* No processing for other channels so return raw value */
187 		*val = raw_val;
188 		break;
189 	}
190 
191 	return IIO_VAL_INT;
192 }
193 
194 static int da9150_gpadc_read_scale(int channel, int *val, int *val2)
195 {
196 	switch (channel) {
197 	case DA9150_GPADC_CHAN_VBAT:
198 		*val = 2932;
199 		*val2 = 1000;
200 		return IIO_VAL_FRACTIONAL;
201 	case DA9150_GPADC_CHAN_TJUNC_CORE:
202 	case DA9150_GPADC_CHAN_TJUNC_OVP:
203 		*val = 1000000;
204 		*val2 = 4420;
205 		return IIO_VAL_FRACTIONAL;
206 	default:
207 		return -EINVAL;
208 	}
209 }
210 
211 static int da9150_gpadc_read_offset(int channel, int *val)
212 {
213 	switch (channel) {
214 	case DA9150_GPADC_CHAN_VBAT:
215 		*val = 1500000 / 2932;
216 		return IIO_VAL_INT;
217 	case DA9150_GPADC_CHAN_TJUNC_CORE:
218 	case DA9150_GPADC_CHAN_TJUNC_OVP:
219 		*val = -144;
220 		return IIO_VAL_INT;
221 	default:
222 		return -EINVAL;
223 	}
224 }
225 
226 static int da9150_gpadc_read_raw(struct iio_dev *indio_dev,
227 				 struct iio_chan_spec const *chan,
228 				 int *val, int *val2, long mask)
229 {
230 	struct da9150_gpadc *gpadc = iio_priv(indio_dev);
231 
232 	if ((chan->channel < DA9150_GPADC_CHAN_GPIOA) ||
233 	    (chan->channel > DA9150_GPADC_CHAN_TJUNC_OVP))
234 		return -EINVAL;
235 
236 	switch (mask) {
237 	case IIO_CHAN_INFO_RAW:
238 	case IIO_CHAN_INFO_PROCESSED:
239 		return da9150_gpadc_read_processed(gpadc, chan->channel,
240 						   chan->address, val);
241 	case IIO_CHAN_INFO_SCALE:
242 		return da9150_gpadc_read_scale(chan->channel, val, val2);
243 	case IIO_CHAN_INFO_OFFSET:
244 		return da9150_gpadc_read_offset(chan->channel, val);
245 	default:
246 		return -EINVAL;
247 	}
248 }
249 
250 static const struct iio_info da9150_gpadc_info = {
251 	.read_raw = &da9150_gpadc_read_raw,
252 	.driver_module = THIS_MODULE,
253 };
254 
255 #define DA9150_GPADC_CHANNEL(_id, _hw_id, _type, chan_info,	\
256 			     _ext_name) {			\
257 	.type = _type,						\
258 	.indexed = 1,						\
259 	.channel = DA9150_GPADC_CHAN_##_id,			\
260 	.address = DA9150_GPADC_HW_CHAN_##_hw_id,		\
261 	.info_mask_separate = chan_info,			\
262 	.extend_name = _ext_name,				\
263 	.datasheet_name = #_id,					\
264 }
265 
266 #define DA9150_GPADC_CHANNEL_RAW(_id, _hw_id, _type, _ext_name)	\
267 	DA9150_GPADC_CHANNEL(_id, _hw_id, _type,		\
268 			     BIT(IIO_CHAN_INFO_RAW), _ext_name)
269 
270 #define DA9150_GPADC_CHANNEL_SCALED(_id, _hw_id, _type, _ext_name)	\
271 	DA9150_GPADC_CHANNEL(_id, _hw_id, _type,			\
272 			     BIT(IIO_CHAN_INFO_RAW) |			\
273 			     BIT(IIO_CHAN_INFO_SCALE) |			\
274 			     BIT(IIO_CHAN_INFO_OFFSET),			\
275 			     _ext_name)
276 
277 #define DA9150_GPADC_CHANNEL_PROCESSED(_id, _hw_id, _type, _ext_name)	\
278 	DA9150_GPADC_CHANNEL(_id, _hw_id, _type,			\
279 			     BIT(IIO_CHAN_INFO_PROCESSED), _ext_name)
280 
281 /* Supported channels */
282 static const struct iio_chan_spec da9150_gpadc_channels[] = {
283 	DA9150_GPADC_CHANNEL_PROCESSED(GPIOA, GPIOA_6V, IIO_VOLTAGE, NULL),
284 	DA9150_GPADC_CHANNEL_PROCESSED(GPIOB, GPIOB_6V, IIO_VOLTAGE, NULL),
285 	DA9150_GPADC_CHANNEL_PROCESSED(GPIOC, GPIOC_6V, IIO_VOLTAGE, NULL),
286 	DA9150_GPADC_CHANNEL_PROCESSED(GPIOD, GPIOD_6V, IIO_VOLTAGE, NULL),
287 	DA9150_GPADC_CHANNEL_PROCESSED(IBUS, IBUS_SENSE, IIO_CURRENT, "ibus"),
288 	DA9150_GPADC_CHANNEL_PROCESSED(VBUS, VBUS_DIV_, IIO_VOLTAGE, "vbus"),
289 	DA9150_GPADC_CHANNEL_PROCESSED(VSYS, VSYS, IIO_VOLTAGE, "vsys"),
290 	DA9150_GPADC_CHANNEL_SCALED(VBAT, VBAT, IIO_VOLTAGE, "vbat"),
291 	DA9150_GPADC_CHANNEL_RAW(TBAT, TBAT, IIO_VOLTAGE, "tbat"),
292 	DA9150_GPADC_CHANNEL_SCALED(TJUNC_CORE, TJUNC_CORE, IIO_TEMP,
293 				    "tjunc_core"),
294 	DA9150_GPADC_CHANNEL_SCALED(TJUNC_OVP, TJUNC_OVP, IIO_TEMP,
295 				    "tjunc_ovp"),
296 };
297 
298 /* Default maps used by da9150-charger */
299 static struct iio_map da9150_gpadc_default_maps[] = {
300 	{
301 		.consumer_dev_name = "da9150-charger",
302 		.consumer_channel = "CHAN_IBUS",
303 		.adc_channel_label = "IBUS",
304 	},
305 	{
306 		.consumer_dev_name = "da9150-charger",
307 		.consumer_channel = "CHAN_VBUS",
308 		.adc_channel_label = "VBUS",
309 	},
310 	{
311 		.consumer_dev_name = "da9150-charger",
312 		.consumer_channel = "CHAN_TJUNC",
313 		.adc_channel_label = "TJUNC_CORE",
314 	},
315 	{
316 		.consumer_dev_name = "da9150-charger",
317 		.consumer_channel = "CHAN_VBAT",
318 		.adc_channel_label = "VBAT",
319 	},
320 	{},
321 };
322 
323 static int da9150_gpadc_probe(struct platform_device *pdev)
324 {
325 	struct device *dev = &pdev->dev;
326 	struct da9150 *da9150 = dev_get_drvdata(dev->parent);
327 	struct da9150_gpadc *gpadc;
328 	struct iio_dev *indio_dev;
329 	int irq, ret;
330 
331 	indio_dev = devm_iio_device_alloc(dev, sizeof(*gpadc));
332 	if (!indio_dev) {
333 		dev_err(&pdev->dev, "Failed to allocate IIO device\n");
334 		return -ENOMEM;
335 	}
336 	gpadc = iio_priv(indio_dev);
337 
338 	platform_set_drvdata(pdev, indio_dev);
339 	gpadc->da9150 = da9150;
340 	gpadc->dev = dev;
341 	mutex_init(&gpadc->lock);
342 	init_completion(&gpadc->complete);
343 
344 	irq = platform_get_irq_byname(pdev, "GPADC");
345 	if (irq < 0) {
346 		dev_err(dev, "Failed to get IRQ: %d\n", irq);
347 		return irq;
348 	}
349 
350 	ret = devm_request_threaded_irq(dev, irq, NULL, da9150_gpadc_irq,
351 					IRQF_ONESHOT, "GPADC", gpadc);
352 	if (ret) {
353 		dev_err(dev, "Failed to request IRQ %d: %d\n", irq, ret);
354 		return ret;
355 	}
356 
357 	ret = iio_map_array_register(indio_dev, da9150_gpadc_default_maps);
358 	if (ret) {
359 		dev_err(dev, "Failed to register IIO maps: %d\n", ret);
360 		return ret;
361 	}
362 
363 	indio_dev->name = dev_name(dev);
364 	indio_dev->dev.parent = dev;
365 	indio_dev->dev.of_node = pdev->dev.of_node;
366 	indio_dev->info = &da9150_gpadc_info;
367 	indio_dev->modes = INDIO_DIRECT_MODE;
368 	indio_dev->channels = da9150_gpadc_channels;
369 	indio_dev->num_channels = ARRAY_SIZE(da9150_gpadc_channels);
370 
371 	ret = iio_device_register(indio_dev);
372 	if (ret) {
373 		dev_err(dev, "Failed to register IIO device: %d\n", ret);
374 		goto iio_map_unreg;
375 	}
376 
377 	return 0;
378 
379 iio_map_unreg:
380 	iio_map_array_unregister(indio_dev);
381 
382 	return ret;
383 }
384 
385 static int da9150_gpadc_remove(struct platform_device *pdev)
386 {
387 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
388 
389 	iio_device_unregister(indio_dev);
390 	iio_map_array_unregister(indio_dev);
391 
392 	return 0;
393 }
394 
395 static struct platform_driver da9150_gpadc_driver = {
396 	.driver = {
397 		.name = "da9150-gpadc",
398 	},
399 	.probe = da9150_gpadc_probe,
400 	.remove = da9150_gpadc_remove,
401 };
402 
403 module_platform_driver(da9150_gpadc_driver);
404 
405 MODULE_DESCRIPTION("GPADC Driver for DA9150");
406 MODULE_AUTHOR("Adam Thomson <Adam.Thomson.Opensource@diasemi.com>");
407 MODULE_LICENSE("GPL");
408