xref: /openbmc/linux/drivers/iio/adc/adi-axi-adc.c (revision e0d07278)
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 	struct iio_buffer *buffer;
108 	const char *dma_name;
109 
110 	if (!device_property_present(dev, "dmas"))
111 		return 0;
112 
113 	if (device_property_read_string(dev, "dma-names", &dma_name))
114 		dma_name = "rx";
115 
116 	buffer = devm_iio_dmaengine_buffer_alloc(indio_dev->dev.parent,
117 						 dma_name);
118 	if (IS_ERR(buffer))
119 		return PTR_ERR(buffer);
120 
121 	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
122 	iio_device_attach_buffer(indio_dev, buffer);
123 
124 	return 0;
125 }
126 
127 static int adi_axi_adc_read_raw(struct iio_dev *indio_dev,
128 				struct iio_chan_spec const *chan,
129 				int *val, int *val2, long mask)
130 {
131 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
132 	struct adi_axi_adc_conv *conv = &st->client->conv;
133 
134 	if (!conv->read_raw)
135 		return -EOPNOTSUPP;
136 
137 	return conv->read_raw(conv, chan, val, val2, mask);
138 }
139 
140 static int adi_axi_adc_write_raw(struct iio_dev *indio_dev,
141 				 struct iio_chan_spec const *chan,
142 				 int val, int val2, long mask)
143 {
144 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
145 	struct adi_axi_adc_conv *conv = &st->client->conv;
146 
147 	if (!conv->write_raw)
148 		return -EOPNOTSUPP;
149 
150 	return conv->write_raw(conv, chan, val, val2, mask);
151 }
152 
153 static int adi_axi_adc_update_scan_mode(struct iio_dev *indio_dev,
154 					const unsigned long *scan_mask)
155 {
156 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
157 	struct adi_axi_adc_conv *conv = &st->client->conv;
158 	unsigned int i, ctrl;
159 
160 	for (i = 0; i < conv->chip_info->num_channels; i++) {
161 		ctrl = adi_axi_adc_read(st, ADI_AXI_REG_CHAN_CTRL(i));
162 
163 		if (test_bit(i, scan_mask))
164 			ctrl |= ADI_AXI_REG_CHAN_CTRL_ENABLE;
165 		else
166 			ctrl &= ~ADI_AXI_REG_CHAN_CTRL_ENABLE;
167 
168 		adi_axi_adc_write(st, ADI_AXI_REG_CHAN_CTRL(i), ctrl);
169 	}
170 
171 	return 0;
172 }
173 
174 static struct adi_axi_adc_conv *adi_axi_adc_conv_register(struct device *dev,
175 							  size_t sizeof_priv)
176 {
177 	struct adi_axi_adc_client *cl;
178 	size_t alloc_size;
179 
180 	alloc_size = ALIGN(sizeof(struct adi_axi_adc_client), IIO_ALIGN);
181 	if (sizeof_priv)
182 		alloc_size += ALIGN(sizeof_priv, IIO_ALIGN);
183 
184 	cl = kzalloc(alloc_size, GFP_KERNEL);
185 	if (!cl)
186 		return ERR_PTR(-ENOMEM);
187 
188 	mutex_lock(&registered_clients_lock);
189 
190 	cl->dev = get_device(dev);
191 
192 	list_add_tail(&cl->entry, &registered_clients);
193 
194 	mutex_unlock(&registered_clients_lock);
195 
196 	return &cl->conv;
197 }
198 
199 static void adi_axi_adc_conv_unregister(struct adi_axi_adc_conv *conv)
200 {
201 	struct adi_axi_adc_client *cl = conv_to_client(conv);
202 
203 	mutex_lock(&registered_clients_lock);
204 
205 	list_del(&cl->entry);
206 	put_device(cl->dev);
207 
208 	mutex_unlock(&registered_clients_lock);
209 
210 	kfree(cl);
211 }
212 
213 static void devm_adi_axi_adc_conv_release(struct device *dev, void *res)
214 {
215 	adi_axi_adc_conv_unregister(*(struct adi_axi_adc_conv **)res);
216 }
217 
218 struct adi_axi_adc_conv *devm_adi_axi_adc_conv_register(struct device *dev,
219 							size_t sizeof_priv)
220 {
221 	struct adi_axi_adc_conv **ptr, *conv;
222 
223 	ptr = devres_alloc(devm_adi_axi_adc_conv_release, sizeof(*ptr),
224 			   GFP_KERNEL);
225 	if (!ptr)
226 		return ERR_PTR(-ENOMEM);
227 
228 	conv = adi_axi_adc_conv_register(dev, sizeof_priv);
229 	if (IS_ERR(conv)) {
230 		devres_free(ptr);
231 		return ERR_CAST(conv);
232 	}
233 
234 	*ptr = conv;
235 	devres_add(dev, ptr);
236 
237 	return conv;
238 }
239 EXPORT_SYMBOL_GPL(devm_adi_axi_adc_conv_register);
240 
241 static ssize_t in_voltage_scale_available_show(struct device *dev,
242 					       struct device_attribute *attr,
243 					       char *buf)
244 {
245 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
246 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
247 	struct adi_axi_adc_conv *conv = &st->client->conv;
248 	size_t len = 0;
249 	int i;
250 
251 	for (i = 0; i < conv->chip_info->num_scales; i++) {
252 		const unsigned int *s = conv->chip_info->scale_table[i];
253 
254 		len += scnprintf(buf + len, PAGE_SIZE - len,
255 				 "%u.%06u ", s[0], s[1]);
256 	}
257 	buf[len - 1] = '\n';
258 
259 	return len;
260 }
261 
262 static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
263 
264 enum {
265 	ADI_AXI_ATTR_SCALE_AVAIL,
266 };
267 
268 #define ADI_AXI_ATTR(_en_, _file_)			\
269 	[ADI_AXI_ATTR_##_en_] = &iio_dev_attr_##_file_.dev_attr.attr
270 
271 static struct attribute *adi_axi_adc_attributes[] = {
272 	ADI_AXI_ATTR(SCALE_AVAIL, in_voltage_scale_available),
273 	NULL
274 };
275 
276 static umode_t axi_adc_attr_is_visible(struct kobject *kobj,
277 				       struct attribute *attr, int n)
278 {
279 	struct device *dev = container_of(kobj, struct device, kobj);
280 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
281 	struct adi_axi_adc_state *st = iio_priv(indio_dev);
282 	struct adi_axi_adc_conv *conv = &st->client->conv;
283 
284 	switch (n) {
285 	case ADI_AXI_ATTR_SCALE_AVAIL:
286 		if (!conv->chip_info->num_scales)
287 			return 0;
288 		return attr->mode;
289 	default:
290 		return attr->mode;
291 	}
292 }
293 
294 static const struct attribute_group adi_axi_adc_attribute_group = {
295 	.attrs = adi_axi_adc_attributes,
296 	.is_visible = axi_adc_attr_is_visible,
297 };
298 
299 static const struct iio_info adi_axi_adc_info = {
300 	.read_raw = &adi_axi_adc_read_raw,
301 	.write_raw = &adi_axi_adc_write_raw,
302 	.attrs = &adi_axi_adc_attribute_group,
303 	.update_scan_mode = &adi_axi_adc_update_scan_mode,
304 };
305 
306 static const struct adi_axi_adc_core_info adi_axi_adc_10_0_a_info = {
307 	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
308 };
309 
310 static struct adi_axi_adc_client *adi_axi_adc_attach_client(struct device *dev)
311 {
312 	const struct adi_axi_adc_core_info *info;
313 	struct adi_axi_adc_client *cl;
314 	struct device_node *cln;
315 
316 	info = of_device_get_match_data(dev);
317 	if (!info)
318 		return ERR_PTR(-ENODEV);
319 
320 	cln = of_parse_phandle(dev->of_node, "adi,adc-dev", 0);
321 	if (!cln) {
322 		dev_err(dev, "No 'adi,adc-dev' node defined\n");
323 		return ERR_PTR(-ENODEV);
324 	}
325 
326 	mutex_lock(&registered_clients_lock);
327 
328 	list_for_each_entry(cl, &registered_clients, entry) {
329 		if (!cl->dev)
330 			continue;
331 
332 		if (cl->dev->of_node != cln)
333 			continue;
334 
335 		if (!try_module_get(cl->dev->driver->owner)) {
336 			mutex_unlock(&registered_clients_lock);
337 			return ERR_PTR(-ENODEV);
338 		}
339 
340 		get_device(cl->dev);
341 		cl->info = info;
342 		mutex_unlock(&registered_clients_lock);
343 		return cl;
344 	}
345 
346 	mutex_unlock(&registered_clients_lock);
347 
348 	return ERR_PTR(-EPROBE_DEFER);
349 }
350 
351 static int adi_axi_adc_setup_channels(struct device *dev,
352 				      struct adi_axi_adc_state *st)
353 {
354 	struct adi_axi_adc_conv *conv = &st->client->conv;
355 	int i, ret;
356 
357 	if (conv->preenable_setup) {
358 		ret = conv->preenable_setup(conv);
359 		if (ret)
360 			return ret;
361 	}
362 
363 	for (i = 0; i < conv->chip_info->num_channels; i++) {
364 		adi_axi_adc_write(st, ADI_AXI_REG_CHAN_CTRL(i),
365 				  ADI_AXI_REG_CHAN_CTRL_DEFAULTS);
366 	}
367 
368 	return 0;
369 }
370 
371 static void axi_adc_reset(struct adi_axi_adc_state *st)
372 {
373 	adi_axi_adc_write(st, ADI_AXI_REG_RSTN, 0);
374 	mdelay(10);
375 	adi_axi_adc_write(st, ADI_AXI_REG_RSTN, ADI_AXI_REG_RSTN_MMCM_RSTN);
376 	mdelay(10);
377 	adi_axi_adc_write(st, ADI_AXI_REG_RSTN,
378 			  ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
379 }
380 
381 static void adi_axi_adc_cleanup(void *data)
382 {
383 	struct adi_axi_adc_client *cl = data;
384 
385 	put_device(cl->dev);
386 	module_put(cl->dev->driver->owner);
387 }
388 
389 static int adi_axi_adc_probe(struct platform_device *pdev)
390 {
391 	struct adi_axi_adc_conv *conv;
392 	struct iio_dev *indio_dev;
393 	struct adi_axi_adc_client *cl;
394 	struct adi_axi_adc_state *st;
395 	unsigned int ver;
396 	int ret;
397 
398 	cl = adi_axi_adc_attach_client(&pdev->dev);
399 	if (IS_ERR(cl))
400 		return PTR_ERR(cl);
401 
402 	ret = devm_add_action_or_reset(&pdev->dev, adi_axi_adc_cleanup, cl);
403 	if (ret)
404 		return ret;
405 
406 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
407 	if (indio_dev == NULL)
408 		return -ENOMEM;
409 
410 	st = iio_priv(indio_dev);
411 	st->client = cl;
412 	cl->state = st;
413 	mutex_init(&st->lock);
414 
415 	st->regs = devm_platform_ioremap_resource(pdev, 0);
416 	if (IS_ERR(st->regs))
417 		return PTR_ERR(st->regs);
418 
419 	conv = &st->client->conv;
420 
421 	axi_adc_reset(st);
422 
423 	ver = adi_axi_adc_read(st, ADI_AXI_REG_VERSION);
424 
425 	if (cl->info->version > ver) {
426 		dev_err(&pdev->dev,
427 			"IP core version is too old. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
428 			ADI_AXI_PCORE_VER_MAJOR(cl->info->version),
429 			ADI_AXI_PCORE_VER_MINOR(cl->info->version),
430 			ADI_AXI_PCORE_VER_PATCH(cl->info->version),
431 			ADI_AXI_PCORE_VER_MAJOR(ver),
432 			ADI_AXI_PCORE_VER_MINOR(ver),
433 			ADI_AXI_PCORE_VER_PATCH(ver));
434 		return -ENODEV;
435 	}
436 
437 	indio_dev->info = &adi_axi_adc_info;
438 	indio_dev->name = "adi-axi-adc";
439 	indio_dev->modes = INDIO_DIRECT_MODE;
440 	indio_dev->num_channels = conv->chip_info->num_channels;
441 	indio_dev->channels = conv->chip_info->channels;
442 
443 	ret = adi_axi_adc_config_dma_buffer(&pdev->dev, indio_dev);
444 	if (ret)
445 		return ret;
446 
447 	ret = adi_axi_adc_setup_channels(&pdev->dev, st);
448 	if (ret)
449 		return ret;
450 
451 	ret = devm_iio_device_register(&pdev->dev, indio_dev);
452 	if (ret)
453 		return ret;
454 
455 	dev_info(&pdev->dev, "AXI ADC IP core (%d.%.2d.%c) probed\n",
456 		 ADI_AXI_PCORE_VER_MAJOR(ver),
457 		 ADI_AXI_PCORE_VER_MINOR(ver),
458 		 ADI_AXI_PCORE_VER_PATCH(ver));
459 
460 	return 0;
461 }
462 
463 /* Match table for of_platform binding */
464 static const struct of_device_id adi_axi_adc_of_match[] = {
465 	{ .compatible = "adi,axi-adc-10.0.a", .data = &adi_axi_adc_10_0_a_info },
466 	{ /* end of list */ }
467 };
468 MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);
469 
470 static struct platform_driver adi_axi_adc_driver = {
471 	.driver = {
472 		.name = KBUILD_MODNAME,
473 		.of_match_table = adi_axi_adc_of_match,
474 	},
475 	.probe = adi_axi_adc_probe,
476 };
477 module_platform_driver(adi_axi_adc_driver);
478 
479 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
480 MODULE_DESCRIPTION("Analog Devices Generic AXI ADC IP core driver");
481 MODULE_LICENSE("GPL v2");
482