xref: /linux/drivers/iio/adc/adi-axi-adc.c (revision bdaedca74d6293b6ac643a8ebe8231b52bf1171b)
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(struct device *dev, void *res)
206 {
207 	adi_axi_adc_conv_unregister(*(struct adi_axi_adc_conv **)res);
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 **ptr, *conv;
214 
215 	ptr = devres_alloc(devm_adi_axi_adc_conv_release, sizeof(*ptr),
216 			   GFP_KERNEL);
217 	if (!ptr)
218 		return ERR_PTR(-ENOMEM);
219 
220 	conv = adi_axi_adc_conv_register(dev, sizeof_priv);
221 	if (IS_ERR(conv)) {
222 		devres_free(ptr);
223 		return ERR_CAST(conv);
224 	}
225 
226 	*ptr = conv;
227 	devres_add(dev, ptr);
228 
229 	return conv;
230 }
231 EXPORT_SYMBOL_GPL(devm_adi_axi_adc_conv_register);
232 
233 static ssize_t in_voltage_scale_available_show(struct device *dev,
234 					       struct device_attribute *attr,
235 					       char *buf)
236 {
237 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
238 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
239 	struct adi_axi_adc_conv *conv = &st->client->conv;
240 	size_t len = 0;
241 	int i;
242 
243 	for (i = 0; i < conv->chip_info->num_scales; i++) {
244 		const unsigned int *s = conv->chip_info->scale_table[i];
245 
246 		len += scnprintf(buf + len, PAGE_SIZE - len,
247 				 "%u.%06u ", s[0], s[1]);
248 	}
249 	buf[len - 1] = '\n';
250 
251 	return len;
252 }
253 
254 static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
255 
256 enum {
257 	ADI_AXI_ATTR_SCALE_AVAIL,
258 };
259 
260 #define ADI_AXI_ATTR(_en_, _file_)			\
261 	[ADI_AXI_ATTR_##_en_] = &iio_dev_attr_##_file_.dev_attr.attr
262 
263 static struct attribute *adi_axi_adc_attributes[] = {
264 	ADI_AXI_ATTR(SCALE_AVAIL, in_voltage_scale_available),
265 	NULL
266 };
267 
268 static umode_t axi_adc_attr_is_visible(struct kobject *kobj,
269 				       struct attribute *attr, int n)
270 {
271 	struct device *dev = kobj_to_dev(kobj);
272 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
273 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
274 	struct adi_axi_adc_conv *conv = &st->client->conv;
275 
276 	switch (n) {
277 	case ADI_AXI_ATTR_SCALE_AVAIL:
278 		if (!conv->chip_info->num_scales)
279 			return 0;
280 		return attr->mode;
281 	default:
282 		return attr->mode;
283 	}
284 }
285 
286 static const struct attribute_group adi_axi_adc_attribute_group = {
287 	.attrs = adi_axi_adc_attributes,
288 	.is_visible = axi_adc_attr_is_visible,
289 };
290 
291 static const struct iio_info adi_axi_adc_info = {
292 	.read_raw = &adi_axi_adc_read_raw,
293 	.write_raw = &adi_axi_adc_write_raw,
294 	.attrs = &adi_axi_adc_attribute_group,
295 	.update_scan_mode = &adi_axi_adc_update_scan_mode,
296 };
297 
298 static const struct adi_axi_adc_core_info adi_axi_adc_10_0_a_info = {
299 	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
300 };
301 
302 static struct adi_axi_adc_client *adi_axi_adc_attach_client(struct device *dev)
303 {
304 	const struct adi_axi_adc_core_info *info;
305 	struct adi_axi_adc_client *cl;
306 	struct device_node *cln;
307 
308 	info = of_device_get_match_data(dev);
309 	if (!info)
310 		return ERR_PTR(-ENODEV);
311 
312 	cln = of_parse_phandle(dev->of_node, "adi,adc-dev", 0);
313 	if (!cln) {
314 		dev_err(dev, "No 'adi,adc-dev' node defined\n");
315 		return ERR_PTR(-ENODEV);
316 	}
317 
318 	mutex_lock(&registered_clients_lock);
319 
320 	list_for_each_entry(cl, &registered_clients, entry) {
321 		if (!cl->dev)
322 			continue;
323 
324 		if (cl->dev->of_node != cln)
325 			continue;
326 
327 		if (!try_module_get(cl->dev->driver->owner)) {
328 			mutex_unlock(&registered_clients_lock);
329 			return ERR_PTR(-ENODEV);
330 		}
331 
332 		get_device(cl->dev);
333 		cl->info = info;
334 		mutex_unlock(&registered_clients_lock);
335 		return cl;
336 	}
337 
338 	mutex_unlock(&registered_clients_lock);
339 
340 	return ERR_PTR(-EPROBE_DEFER);
341 }
342 
343 static int adi_axi_adc_setup_channels(struct device *dev,
344 				      struct adi_axi_adc_state *st)
345 {
346 	struct adi_axi_adc_conv *conv = &st->client->conv;
347 	int i, ret;
348 
349 	if (conv->preenable_setup) {
350 		ret = conv->preenable_setup(conv);
351 		if (ret)
352 			return ret;
353 	}
354 
355 	for (i = 0; i < conv->chip_info->num_channels; i++) {
356 		adi_axi_adc_write(st, ADI_AXI_REG_CHAN_CTRL(i),
357 				  ADI_AXI_REG_CHAN_CTRL_DEFAULTS);
358 	}
359 
360 	return 0;
361 }
362 
363 static void axi_adc_reset(struct adi_axi_adc_state *st)
364 {
365 	adi_axi_adc_write(st, ADI_AXI_REG_RSTN, 0);
366 	mdelay(10);
367 	adi_axi_adc_write(st, ADI_AXI_REG_RSTN, ADI_AXI_REG_RSTN_MMCM_RSTN);
368 	mdelay(10);
369 	adi_axi_adc_write(st, ADI_AXI_REG_RSTN,
370 			  ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
371 }
372 
373 static void adi_axi_adc_cleanup(void *data)
374 {
375 	struct adi_axi_adc_client *cl = data;
376 
377 	put_device(cl->dev);
378 	module_put(cl->dev->driver->owner);
379 }
380 
381 static int adi_axi_adc_probe(struct platform_device *pdev)
382 {
383 	struct adi_axi_adc_conv *conv;
384 	struct iio_dev *indio_dev;
385 	struct adi_axi_adc_client *cl;
386 	struct adi_axi_adc_state *st;
387 	unsigned int ver;
388 	int ret;
389 
390 	cl = adi_axi_adc_attach_client(&pdev->dev);
391 	if (IS_ERR(cl))
392 		return PTR_ERR(cl);
393 
394 	ret = devm_add_action_or_reset(&pdev->dev, adi_axi_adc_cleanup, cl);
395 	if (ret)
396 		return ret;
397 
398 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
399 	if (indio_dev == NULL)
400 		return -ENOMEM;
401 
402 	st = iio_priv(indio_dev);
403 	st->client = cl;
404 	cl->state = st;
405 	mutex_init(&st->lock);
406 
407 	st->regs = devm_platform_ioremap_resource(pdev, 0);
408 	if (IS_ERR(st->regs))
409 		return PTR_ERR(st->regs);
410 
411 	conv = &st->client->conv;
412 
413 	axi_adc_reset(st);
414 
415 	ver = adi_axi_adc_read(st, ADI_AXI_REG_VERSION);
416 
417 	if (cl->info->version > ver) {
418 		dev_err(&pdev->dev,
419 			"IP core version is too old. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
420 			ADI_AXI_PCORE_VER_MAJOR(cl->info->version),
421 			ADI_AXI_PCORE_VER_MINOR(cl->info->version),
422 			ADI_AXI_PCORE_VER_PATCH(cl->info->version),
423 			ADI_AXI_PCORE_VER_MAJOR(ver),
424 			ADI_AXI_PCORE_VER_MINOR(ver),
425 			ADI_AXI_PCORE_VER_PATCH(ver));
426 		return -ENODEV;
427 	}
428 
429 	indio_dev->info = &adi_axi_adc_info;
430 	indio_dev->name = "adi-axi-adc";
431 	indio_dev->modes = INDIO_DIRECT_MODE;
432 	indio_dev->num_channels = conv->chip_info->num_channels;
433 	indio_dev->channels = conv->chip_info->channels;
434 
435 	ret = adi_axi_adc_config_dma_buffer(&pdev->dev, indio_dev);
436 	if (ret)
437 		return ret;
438 
439 	ret = adi_axi_adc_setup_channels(&pdev->dev, st);
440 	if (ret)
441 		return ret;
442 
443 	ret = devm_iio_device_register(&pdev->dev, indio_dev);
444 	if (ret)
445 		return ret;
446 
447 	dev_info(&pdev->dev, "AXI ADC IP core (%d.%.2d.%c) probed\n",
448 		 ADI_AXI_PCORE_VER_MAJOR(ver),
449 		 ADI_AXI_PCORE_VER_MINOR(ver),
450 		 ADI_AXI_PCORE_VER_PATCH(ver));
451 
452 	return 0;
453 }
454 
455 /* Match table for of_platform binding */
456 static const struct of_device_id adi_axi_adc_of_match[] = {
457 	{ .compatible = "adi,axi-adc-10.0.a", .data = &adi_axi_adc_10_0_a_info },
458 	{ /* end of list */ }
459 };
460 MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);
461 
462 static struct platform_driver adi_axi_adc_driver = {
463 	.driver = {
464 		.name = KBUILD_MODNAME,
465 		.of_match_table = adi_axi_adc_of_match,
466 	},
467 	.probe = adi_axi_adc_probe,
468 };
469 module_platform_driver(adi_axi_adc_driver);
470 
471 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
472 MODULE_DESCRIPTION("Analog Devices Generic AXI ADC IP core driver");
473 MODULE_LICENSE("GPL v2");
474