xref: /openbmc/linux/drivers/iio/adc/adi-axi-adc.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Analog Devices Generic AXI ADC IP core
4  * Link: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
5  *
6  * Copyright 2012-2020 Analog Devices Inc.
7  */
8 
9 #include <linux/bitfield.h>
10 #include <linux/clk.h>
11 #include <linux/io.h>
12 #include <linux/delay.h>
13 #include <linux/module.h>
14 #include <linux/of_device.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17 
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/buffer-dmaengine.h>
22 
23 #include <linux/fpga/adi-axi-common.h>
24 #include <linux/iio/adc/adi-axi-adc.h>
25 
26 /*
27  * Register definitions:
28  *   https://wiki.analog.com/resources/fpga/docs/axi_adc_ip#register_map
29  */
30 
31 /* ADC controls */
32 
33 #define ADI_AXI_REG_RSTN			0x0040
34 #define   ADI_AXI_REG_RSTN_CE_N			BIT(2)
35 #define   ADI_AXI_REG_RSTN_MMCM_RSTN		BIT(1)
36 #define   ADI_AXI_REG_RSTN_RSTN			BIT(0)
37 
38 /* ADC Channel controls */
39 
40 #define ADI_AXI_REG_CHAN_CTRL(c)		(0x0400 + (c) * 0x40)
41 #define   ADI_AXI_REG_CHAN_CTRL_LB_OWR		BIT(11)
42 #define   ADI_AXI_REG_CHAN_CTRL_PN_SEL_OWR	BIT(10)
43 #define   ADI_AXI_REG_CHAN_CTRL_IQCOR_EN	BIT(9)
44 #define   ADI_AXI_REG_CHAN_CTRL_DCFILT_EN	BIT(8)
45 #define   ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT	BIT(6)
46 #define   ADI_AXI_REG_CHAN_CTRL_FMT_TYPE	BIT(5)
47 #define   ADI_AXI_REG_CHAN_CTRL_FMT_EN		BIT(4)
48 #define   ADI_AXI_REG_CHAN_CTRL_PN_TYPE_OWR	BIT(1)
49 #define   ADI_AXI_REG_CHAN_CTRL_ENABLE		BIT(0)
50 
51 #define ADI_AXI_REG_CHAN_CTRL_DEFAULTS		\
52 	(ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT |	\
53 	 ADI_AXI_REG_CHAN_CTRL_FMT_EN |		\
54 	 ADI_AXI_REG_CHAN_CTRL_ENABLE)
55 
56 struct adi_axi_adc_core_info {
57 	unsigned int				version;
58 };
59 
60 struct adi_axi_adc_state {
61 	struct mutex				lock;
62 
63 	struct adi_axi_adc_client		*client;
64 	void __iomem				*regs;
65 };
66 
67 struct adi_axi_adc_client {
68 	struct list_head			entry;
69 	struct adi_axi_adc_conv			conv;
70 	struct adi_axi_adc_state		*state;
71 	struct device				*dev;
72 	const struct adi_axi_adc_core_info	*info;
73 };
74 
75 static LIST_HEAD(registered_clients);
76 static DEFINE_MUTEX(registered_clients_lock);
77 
78 static struct adi_axi_adc_client *conv_to_client(struct adi_axi_adc_conv *conv)
79 {
80 	return container_of(conv, struct adi_axi_adc_client, conv);
81 }
82 
83 void *adi_axi_adc_conv_priv(struct adi_axi_adc_conv *conv)
84 {
85 	struct adi_axi_adc_client *cl = conv_to_client(conv);
86 
87 	return (char *)cl + ALIGN(sizeof(struct adi_axi_adc_client), IIO_ALIGN);
88 }
89 EXPORT_SYMBOL_GPL(adi_axi_adc_conv_priv);
90 
91 static void adi_axi_adc_write(struct adi_axi_adc_state *st,
92 			      unsigned int reg,
93 			      unsigned int val)
94 {
95 	iowrite32(val, st->regs + reg);
96 }
97 
98 static unsigned int adi_axi_adc_read(struct adi_axi_adc_state *st,
99 				     unsigned int reg)
100 {
101 	return ioread32(st->regs + reg);
102 }
103 
104 static int adi_axi_adc_config_dma_buffer(struct device *dev,
105 					 struct iio_dev *indio_dev)
106 {
107 	const char *dma_name;
108 
109 	if (!device_property_present(dev, "dmas"))
110 		return 0;
111 
112 	if (device_property_read_string(dev, "dma-names", &dma_name))
113 		dma_name = "rx";
114 
115 	return devm_iio_dmaengine_buffer_setup(indio_dev->dev.parent,
116 					       indio_dev, dma_name);
117 }
118 
119 static int adi_axi_adc_read_raw(struct iio_dev *indio_dev,
120 				struct iio_chan_spec const *chan,
121 				int *val, int *val2, long mask)
122 {
123 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
124 	struct adi_axi_adc_conv *conv = &st->client->conv;
125 
126 	if (!conv->read_raw)
127 		return -EOPNOTSUPP;
128 
129 	return conv->read_raw(conv, chan, val, val2, mask);
130 }
131 
132 static int adi_axi_adc_write_raw(struct iio_dev *indio_dev,
133 				 struct iio_chan_spec const *chan,
134 				 int val, int val2, long mask)
135 {
136 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
137 	struct adi_axi_adc_conv *conv = &st->client->conv;
138 
139 	if (!conv->write_raw)
140 		return -EOPNOTSUPP;
141 
142 	return conv->write_raw(conv, chan, val, val2, mask);
143 }
144 
145 static int adi_axi_adc_update_scan_mode(struct iio_dev *indio_dev,
146 					const unsigned long *scan_mask)
147 {
148 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
149 	struct adi_axi_adc_conv *conv = &st->client->conv;
150 	unsigned int i, ctrl;
151 
152 	for (i = 0; i < conv->chip_info->num_channels; i++) {
153 		ctrl = adi_axi_adc_read(st, ADI_AXI_REG_CHAN_CTRL(i));
154 
155 		if (test_bit(i, scan_mask))
156 			ctrl |= ADI_AXI_REG_CHAN_CTRL_ENABLE;
157 		else
158 			ctrl &= ~ADI_AXI_REG_CHAN_CTRL_ENABLE;
159 
160 		adi_axi_adc_write(st, ADI_AXI_REG_CHAN_CTRL(i), ctrl);
161 	}
162 
163 	return 0;
164 }
165 
166 static struct adi_axi_adc_conv *adi_axi_adc_conv_register(struct device *dev,
167 							  size_t sizeof_priv)
168 {
169 	struct adi_axi_adc_client *cl;
170 	size_t alloc_size;
171 
172 	alloc_size = ALIGN(sizeof(struct adi_axi_adc_client), IIO_ALIGN);
173 	if (sizeof_priv)
174 		alloc_size += ALIGN(sizeof_priv, IIO_ALIGN);
175 
176 	cl = kzalloc(alloc_size, GFP_KERNEL);
177 	if (!cl)
178 		return ERR_PTR(-ENOMEM);
179 
180 	mutex_lock(&registered_clients_lock);
181 
182 	cl->dev = get_device(dev);
183 
184 	list_add_tail(&cl->entry, &registered_clients);
185 
186 	mutex_unlock(&registered_clients_lock);
187 
188 	return &cl->conv;
189 }
190 
191 static void adi_axi_adc_conv_unregister(struct adi_axi_adc_conv *conv)
192 {
193 	struct adi_axi_adc_client *cl = conv_to_client(conv);
194 
195 	mutex_lock(&registered_clients_lock);
196 
197 	list_del(&cl->entry);
198 	put_device(cl->dev);
199 
200 	mutex_unlock(&registered_clients_lock);
201 
202 	kfree(cl);
203 }
204 
205 static void devm_adi_axi_adc_conv_release(void *conv)
206 {
207 	adi_axi_adc_conv_unregister(conv);
208 }
209 
210 struct adi_axi_adc_conv *devm_adi_axi_adc_conv_register(struct device *dev,
211 							size_t sizeof_priv)
212 {
213 	struct adi_axi_adc_conv *conv;
214 	int ret;
215 
216 	conv = adi_axi_adc_conv_register(dev, sizeof_priv);
217 	if (IS_ERR(conv))
218 		return conv;
219 
220 	ret = devm_add_action_or_reset(dev, devm_adi_axi_adc_conv_release,
221 				       conv);
222 	if (ret)
223 		return ERR_PTR(ret);
224 
225 	return conv;
226 }
227 EXPORT_SYMBOL_GPL(devm_adi_axi_adc_conv_register);
228 
229 static ssize_t in_voltage_scale_available_show(struct device *dev,
230 					       struct device_attribute *attr,
231 					       char *buf)
232 {
233 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
234 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
235 	struct adi_axi_adc_conv *conv = &st->client->conv;
236 	size_t len = 0;
237 	int i;
238 
239 	for (i = 0; i < conv->chip_info->num_scales; i++) {
240 		const unsigned int *s = conv->chip_info->scale_table[i];
241 
242 		len += scnprintf(buf + len, PAGE_SIZE - len,
243 				 "%u.%06u ", s[0], s[1]);
244 	}
245 	buf[len - 1] = '\n';
246 
247 	return len;
248 }
249 
250 static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
251 
252 enum {
253 	ADI_AXI_ATTR_SCALE_AVAIL,
254 };
255 
256 #define ADI_AXI_ATTR(_en_, _file_)			\
257 	[ADI_AXI_ATTR_##_en_] = &iio_dev_attr_##_file_.dev_attr.attr
258 
259 static struct attribute *adi_axi_adc_attributes[] = {
260 	ADI_AXI_ATTR(SCALE_AVAIL, in_voltage_scale_available),
261 	NULL
262 };
263 
264 static umode_t axi_adc_attr_is_visible(struct kobject *kobj,
265 				       struct attribute *attr, int n)
266 {
267 	struct device *dev = kobj_to_dev(kobj);
268 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
269 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
270 	struct adi_axi_adc_conv *conv = &st->client->conv;
271 
272 	switch (n) {
273 	case ADI_AXI_ATTR_SCALE_AVAIL:
274 		if (!conv->chip_info->num_scales)
275 			return 0;
276 		return attr->mode;
277 	default:
278 		return attr->mode;
279 	}
280 }
281 
282 static const struct attribute_group adi_axi_adc_attribute_group = {
283 	.attrs = adi_axi_adc_attributes,
284 	.is_visible = axi_adc_attr_is_visible,
285 };
286 
287 static const struct iio_info adi_axi_adc_info = {
288 	.read_raw = &adi_axi_adc_read_raw,
289 	.write_raw = &adi_axi_adc_write_raw,
290 	.attrs = &adi_axi_adc_attribute_group,
291 	.update_scan_mode = &adi_axi_adc_update_scan_mode,
292 };
293 
294 static const struct adi_axi_adc_core_info adi_axi_adc_10_0_a_info = {
295 	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
296 };
297 
298 static struct adi_axi_adc_client *adi_axi_adc_attach_client(struct device *dev)
299 {
300 	const struct adi_axi_adc_core_info *info;
301 	struct adi_axi_adc_client *cl;
302 	struct device_node *cln;
303 
304 	info = of_device_get_match_data(dev);
305 	if (!info)
306 		return ERR_PTR(-ENODEV);
307 
308 	cln = of_parse_phandle(dev->of_node, "adi,adc-dev", 0);
309 	if (!cln) {
310 		dev_err(dev, "No 'adi,adc-dev' node defined\n");
311 		return ERR_PTR(-ENODEV);
312 	}
313 
314 	mutex_lock(&registered_clients_lock);
315 
316 	list_for_each_entry(cl, &registered_clients, entry) {
317 		if (!cl->dev)
318 			continue;
319 
320 		if (cl->dev->of_node != cln)
321 			continue;
322 
323 		if (!try_module_get(cl->dev->driver->owner)) {
324 			mutex_unlock(&registered_clients_lock);
325 			return ERR_PTR(-ENODEV);
326 		}
327 
328 		get_device(cl->dev);
329 		cl->info = info;
330 		mutex_unlock(&registered_clients_lock);
331 		return cl;
332 	}
333 
334 	mutex_unlock(&registered_clients_lock);
335 
336 	return ERR_PTR(-EPROBE_DEFER);
337 }
338 
339 static int adi_axi_adc_setup_channels(struct device *dev,
340 				      struct adi_axi_adc_state *st)
341 {
342 	struct adi_axi_adc_conv *conv = &st->client->conv;
343 	int i, ret;
344 
345 	if (conv->preenable_setup) {
346 		ret = conv->preenable_setup(conv);
347 		if (ret)
348 			return ret;
349 	}
350 
351 	for (i = 0; i < conv->chip_info->num_channels; i++) {
352 		adi_axi_adc_write(st, ADI_AXI_REG_CHAN_CTRL(i),
353 				  ADI_AXI_REG_CHAN_CTRL_DEFAULTS);
354 	}
355 
356 	return 0;
357 }
358 
359 static void axi_adc_reset(struct adi_axi_adc_state *st)
360 {
361 	adi_axi_adc_write(st, ADI_AXI_REG_RSTN, 0);
362 	mdelay(10);
363 	adi_axi_adc_write(st, ADI_AXI_REG_RSTN, ADI_AXI_REG_RSTN_MMCM_RSTN);
364 	mdelay(10);
365 	adi_axi_adc_write(st, ADI_AXI_REG_RSTN,
366 			  ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
367 }
368 
369 static void adi_axi_adc_cleanup(void *data)
370 {
371 	struct adi_axi_adc_client *cl = data;
372 
373 	put_device(cl->dev);
374 	module_put(cl->dev->driver->owner);
375 }
376 
377 static int adi_axi_adc_probe(struct platform_device *pdev)
378 {
379 	struct adi_axi_adc_conv *conv;
380 	struct iio_dev *indio_dev;
381 	struct adi_axi_adc_client *cl;
382 	struct adi_axi_adc_state *st;
383 	unsigned int ver;
384 	int ret;
385 
386 	cl = adi_axi_adc_attach_client(&pdev->dev);
387 	if (IS_ERR(cl))
388 		return PTR_ERR(cl);
389 
390 	ret = devm_add_action_or_reset(&pdev->dev, adi_axi_adc_cleanup, cl);
391 	if (ret)
392 		return ret;
393 
394 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
395 	if (indio_dev == NULL)
396 		return -ENOMEM;
397 
398 	st = iio_priv(indio_dev);
399 	st->client = cl;
400 	cl->state = st;
401 	mutex_init(&st->lock);
402 
403 	st->regs = devm_platform_ioremap_resource(pdev, 0);
404 	if (IS_ERR(st->regs))
405 		return PTR_ERR(st->regs);
406 
407 	conv = &st->client->conv;
408 
409 	axi_adc_reset(st);
410 
411 	ver = adi_axi_adc_read(st, ADI_AXI_REG_VERSION);
412 
413 	if (cl->info->version > ver) {
414 		dev_err(&pdev->dev,
415 			"IP core version is too old. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
416 			ADI_AXI_PCORE_VER_MAJOR(cl->info->version),
417 			ADI_AXI_PCORE_VER_MINOR(cl->info->version),
418 			ADI_AXI_PCORE_VER_PATCH(cl->info->version),
419 			ADI_AXI_PCORE_VER_MAJOR(ver),
420 			ADI_AXI_PCORE_VER_MINOR(ver),
421 			ADI_AXI_PCORE_VER_PATCH(ver));
422 		return -ENODEV;
423 	}
424 
425 	indio_dev->info = &adi_axi_adc_info;
426 	indio_dev->name = "adi-axi-adc";
427 	indio_dev->modes = INDIO_DIRECT_MODE;
428 	indio_dev->num_channels = conv->chip_info->num_channels;
429 	indio_dev->channels = conv->chip_info->channels;
430 
431 	ret = adi_axi_adc_config_dma_buffer(&pdev->dev, indio_dev);
432 	if (ret)
433 		return ret;
434 
435 	ret = adi_axi_adc_setup_channels(&pdev->dev, st);
436 	if (ret)
437 		return ret;
438 
439 	ret = devm_iio_device_register(&pdev->dev, indio_dev);
440 	if (ret)
441 		return ret;
442 
443 	dev_info(&pdev->dev, "AXI ADC IP core (%d.%.2d.%c) probed\n",
444 		 ADI_AXI_PCORE_VER_MAJOR(ver),
445 		 ADI_AXI_PCORE_VER_MINOR(ver),
446 		 ADI_AXI_PCORE_VER_PATCH(ver));
447 
448 	return 0;
449 }
450 
451 /* Match table for of_platform binding */
452 static const struct of_device_id adi_axi_adc_of_match[] = {
453 	{ .compatible = "adi,axi-adc-10.0.a", .data = &adi_axi_adc_10_0_a_info },
454 	{ /* end of list */ }
455 };
456 MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);
457 
458 static struct platform_driver adi_axi_adc_driver = {
459 	.driver = {
460 		.name = KBUILD_MODNAME,
461 		.of_match_table = adi_axi_adc_of_match,
462 	},
463 	.probe = adi_axi_adc_probe,
464 };
465 module_platform_driver(adi_axi_adc_driver);
466 
467 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
468 MODULE_DESCRIPTION("Analog Devices Generic AXI ADC IP core driver");
469 MODULE_LICENSE("GPL v2");
470