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/cleanup.h>
11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/delay.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/of.h>
18 #include <linux/platform_device.h>
19 #include <linux/property.h>
20 #include <linux/regmap.h>
21 #include <linux/slab.h>
22
23 #include <linux/fpga/adi-axi-common.h>
24
25 #include <linux/iio/backend.h>
26 #include <linux/iio/buffer-dmaengine.h>
27 #include <linux/iio/buffer.h>
28 #include <linux/iio/iio.h>
29
30 /*
31 * Register definitions:
32 * https://wiki.analog.com/resources/fpga/docs/axi_adc_ip#register_map
33 */
34
35 /* ADC controls */
36
37 #define ADI_AXI_REG_RSTN 0x0040
38 #define ADI_AXI_REG_RSTN_CE_N BIT(2)
39 #define ADI_AXI_REG_RSTN_MMCM_RSTN BIT(1)
40 #define ADI_AXI_REG_RSTN_RSTN BIT(0)
41
42 #define ADI_AXI_ADC_REG_CTRL 0x0044
43 #define ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK BIT(1)
44
45 #define ADI_AXI_ADC_REG_DRP_STATUS 0x0074
46 #define ADI_AXI_ADC_DRP_LOCKED BIT(17)
47
48 /* ADC Channel controls */
49
50 #define ADI_AXI_REG_CHAN_CTRL(c) (0x0400 + (c) * 0x40)
51 #define ADI_AXI_REG_CHAN_CTRL_LB_OWR BIT(11)
52 #define ADI_AXI_REG_CHAN_CTRL_PN_SEL_OWR BIT(10)
53 #define ADI_AXI_REG_CHAN_CTRL_IQCOR_EN BIT(9)
54 #define ADI_AXI_REG_CHAN_CTRL_DCFILT_EN BIT(8)
55 #define ADI_AXI_REG_CHAN_CTRL_FMT_MASK GENMASK(6, 4)
56 #define ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT BIT(6)
57 #define ADI_AXI_REG_CHAN_CTRL_FMT_TYPE BIT(5)
58 #define ADI_AXI_REG_CHAN_CTRL_FMT_EN BIT(4)
59 #define ADI_AXI_REG_CHAN_CTRL_PN_TYPE_OWR BIT(1)
60 #define ADI_AXI_REG_CHAN_CTRL_ENABLE BIT(0)
61
62 #define ADI_AXI_ADC_REG_CHAN_STATUS(c) (0x0404 + (c) * 0x40)
63 #define ADI_AXI_ADC_CHAN_STAT_PN_MASK GENMASK(2, 1)
64 /* out of sync */
65 #define ADI_AXI_ADC_CHAN_STAT_PN_OOS BIT(1)
66 /* spurious out of sync */
67 #define ADI_AXI_ADC_CHAN_STAT_PN_ERR BIT(2)
68
69 #define ADI_AXI_ADC_REG_CHAN_CTRL_3(c) (0x0418 + (c) * 0x40)
70 #define ADI_AXI_ADC_CHAN_PN_SEL_MASK GENMASK(19, 16)
71
72 /* IO Delays */
73 #define ADI_AXI_ADC_REG_DELAY(l) (0x0800 + (l) * 0x4)
74 #define AXI_ADC_DELAY_CTRL_MASK GENMASK(4, 0)
75
76 #define ADI_AXI_ADC_MAX_IO_NUM_LANES 15
77
78 #define ADI_AXI_REG_CHAN_CTRL_DEFAULTS \
79 (ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT | \
80 ADI_AXI_REG_CHAN_CTRL_FMT_EN | \
81 ADI_AXI_REG_CHAN_CTRL_ENABLE)
82
83 struct adi_axi_adc_state {
84 struct regmap *regmap;
85 struct device *dev;
86 /* lock to protect multiple accesses to the device registers */
87 struct mutex lock;
88 };
89
axi_adc_enable(struct iio_backend * back)90 static int axi_adc_enable(struct iio_backend *back)
91 {
92 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
93 unsigned int __val;
94 int ret;
95
96 guard(mutex)(&st->lock);
97 ret = regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
98 ADI_AXI_REG_RSTN_MMCM_RSTN);
99 if (ret)
100 return ret;
101
102 /*
103 * Make sure the DRP (Dynamic Reconfiguration Port) is locked. Not all
104 * designs really use it but if they don't we still get the lock bit
105 * set. So let's do it all the time so the code is generic.
106 */
107 ret = regmap_read_poll_timeout(st->regmap, ADI_AXI_ADC_REG_DRP_STATUS,
108 __val, __val & ADI_AXI_ADC_DRP_LOCKED,
109 100, 1000);
110 if (ret)
111 return ret;
112
113 return regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
114 ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
115 }
116
axi_adc_disable(struct iio_backend * back)117 static void axi_adc_disable(struct iio_backend *back)
118 {
119 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
120
121 guard(mutex)(&st->lock);
122 regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
123 }
124
axi_adc_data_format_set(struct iio_backend * back,unsigned int chan,const struct iio_backend_data_fmt * data)125 static int axi_adc_data_format_set(struct iio_backend *back, unsigned int chan,
126 const struct iio_backend_data_fmt *data)
127 {
128 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
129 u32 val;
130
131 if (!data->enable)
132 return regmap_clear_bits(st->regmap,
133 ADI_AXI_REG_CHAN_CTRL(chan),
134 ADI_AXI_REG_CHAN_CTRL_FMT_EN);
135
136 val = FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_EN, true);
137 if (data->sign_extend)
138 val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT, true);
139 if (data->type == IIO_BACKEND_OFFSET_BINARY)
140 val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_TYPE, true);
141
142 return regmap_update_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
143 ADI_AXI_REG_CHAN_CTRL_FMT_MASK, val);
144 }
145
axi_adc_data_sample_trigger(struct iio_backend * back,enum iio_backend_sample_trigger trigger)146 static int axi_adc_data_sample_trigger(struct iio_backend *back,
147 enum iio_backend_sample_trigger trigger)
148 {
149 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
150
151 switch (trigger) {
152 case IIO_BACKEND_SAMPLE_TRIGGER_EDGE_RISING:
153 return regmap_clear_bits(st->regmap, ADI_AXI_ADC_REG_CTRL,
154 ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK);
155 case IIO_BACKEND_SAMPLE_TRIGGER_EDGE_FALLING:
156 return regmap_set_bits(st->regmap, ADI_AXI_ADC_REG_CTRL,
157 ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK);
158 default:
159 return -EINVAL;
160 }
161 }
162
axi_adc_iodelays_set(struct iio_backend * back,unsigned int lane,unsigned int tap)163 static int axi_adc_iodelays_set(struct iio_backend *back, unsigned int lane,
164 unsigned int tap)
165 {
166 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
167 int ret;
168 u32 val;
169
170 if (tap > FIELD_MAX(AXI_ADC_DELAY_CTRL_MASK))
171 return -EINVAL;
172 if (lane > ADI_AXI_ADC_MAX_IO_NUM_LANES)
173 return -EINVAL;
174
175 guard(mutex)(&st->lock);
176 ret = regmap_write(st->regmap, ADI_AXI_ADC_REG_DELAY(lane), tap);
177 if (ret)
178 return ret;
179 /*
180 * If readback is ~0, that means there are issues with the
181 * delay_clk.
182 */
183 ret = regmap_read(st->regmap, ADI_AXI_ADC_REG_DELAY(lane), &val);
184 if (ret)
185 return ret;
186 if (val == U32_MAX)
187 return -EIO;
188
189 return 0;
190 }
191
axi_adc_test_pattern_set(struct iio_backend * back,unsigned int chan,enum iio_backend_test_pattern pattern)192 static int axi_adc_test_pattern_set(struct iio_backend *back,
193 unsigned int chan,
194 enum iio_backend_test_pattern pattern)
195 {
196 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
197
198 switch (pattern) {
199 case IIO_BACKEND_NO_TEST_PATTERN:
200 /* nothing to do */
201 return 0;
202 case IIO_BACKEND_ADI_PRBS_9A:
203 return regmap_update_bits(st->regmap, ADI_AXI_ADC_REG_CHAN_CTRL_3(chan),
204 ADI_AXI_ADC_CHAN_PN_SEL_MASK,
205 FIELD_PREP(ADI_AXI_ADC_CHAN_PN_SEL_MASK, 0));
206 case IIO_BACKEND_ADI_PRBS_23A:
207 return regmap_update_bits(st->regmap, ADI_AXI_ADC_REG_CHAN_CTRL_3(chan),
208 ADI_AXI_ADC_CHAN_PN_SEL_MASK,
209 FIELD_PREP(ADI_AXI_ADC_CHAN_PN_SEL_MASK, 1));
210 default:
211 return -EINVAL;
212 }
213 }
214
axi_adc_read_chan_status(struct adi_axi_adc_state * st,unsigned int chan,unsigned int * status)215 static int axi_adc_read_chan_status(struct adi_axi_adc_state *st, unsigned int chan,
216 unsigned int *status)
217 {
218 int ret;
219
220 guard(mutex)(&st->lock);
221 /* reset test bits by setting them */
222 ret = regmap_write(st->regmap, ADI_AXI_ADC_REG_CHAN_STATUS(chan),
223 ADI_AXI_ADC_CHAN_STAT_PN_MASK);
224 if (ret)
225 return ret;
226
227 /* let's give enough time to validate or erroring the incoming pattern */
228 fsleep(1000);
229
230 return regmap_read(st->regmap, ADI_AXI_ADC_REG_CHAN_STATUS(chan),
231 status);
232 }
233
axi_adc_chan_status(struct iio_backend * back,unsigned int chan,bool * error)234 static int axi_adc_chan_status(struct iio_backend *back, unsigned int chan,
235 bool *error)
236 {
237 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
238 u32 val;
239 int ret;
240
241 ret = axi_adc_read_chan_status(st, chan, &val);
242 if (ret)
243 return ret;
244
245 if (ADI_AXI_ADC_CHAN_STAT_PN_MASK & val)
246 *error = true;
247 else
248 *error = false;
249
250 return 0;
251 }
252
axi_adc_debugfs_print_chan_status(struct iio_backend * back,unsigned int chan,char * buf,size_t len)253 static int axi_adc_debugfs_print_chan_status(struct iio_backend *back,
254 unsigned int chan, char *buf,
255 size_t len)
256 {
257 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
258 u32 val;
259 int ret;
260
261 ret = axi_adc_read_chan_status(st, chan, &val);
262 if (ret)
263 return ret;
264
265 /*
266 * PN_ERR is cleared in case out of sync is set. Hence, no point in
267 * checking both bits.
268 */
269 if (val & ADI_AXI_ADC_CHAN_STAT_PN_OOS)
270 return scnprintf(buf, len, "CH%u: Out of Sync.\n", chan);
271 if (val & ADI_AXI_ADC_CHAN_STAT_PN_ERR)
272 return scnprintf(buf, len, "CH%u: Spurious Out of Sync.\n", chan);
273
274 return scnprintf(buf, len, "CH%u: OK.\n", chan);
275 }
276
axi_adc_chan_enable(struct iio_backend * back,unsigned int chan)277 static int axi_adc_chan_enable(struct iio_backend *back, unsigned int chan)
278 {
279 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
280
281 return regmap_set_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
282 ADI_AXI_REG_CHAN_CTRL_ENABLE);
283 }
284
axi_adc_chan_disable(struct iio_backend * back,unsigned int chan)285 static int axi_adc_chan_disable(struct iio_backend *back, unsigned int chan)
286 {
287 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
288
289 return regmap_clear_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
290 ADI_AXI_REG_CHAN_CTRL_ENABLE);
291 }
292
axi_adc_request_buffer(struct iio_backend * back,struct iio_dev * indio_dev)293 static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
294 struct iio_dev *indio_dev)
295 {
296 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
297 const char *dma_name;
298
299 if (device_property_read_string(st->dev, "dma-names", &dma_name))
300 dma_name = "rx";
301
302 return iio_dmaengine_buffer_setup(st->dev, indio_dev, dma_name);
303 }
304
axi_adc_free_buffer(struct iio_backend * back,struct iio_buffer * buffer)305 static void axi_adc_free_buffer(struct iio_backend *back,
306 struct iio_buffer *buffer)
307 {
308 iio_dmaengine_buffer_free(buffer);
309 }
310
axi_adc_reg_access(struct iio_backend * back,unsigned int reg,unsigned int writeval,unsigned int * readval)311 static int axi_adc_reg_access(struct iio_backend *back, unsigned int reg,
312 unsigned int writeval, unsigned int *readval)
313 {
314 struct adi_axi_adc_state *st = iio_backend_get_priv(back);
315
316 if (readval)
317 return regmap_read(st->regmap, reg, readval);
318
319 return regmap_write(st->regmap, reg, writeval);
320 }
321
322 static const struct regmap_config axi_adc_regmap_config = {
323 .val_bits = 32,
324 .reg_bits = 32,
325 .reg_stride = 4,
326 };
327
328 static const struct iio_backend_ops adi_axi_adc_ops = {
329 .enable = axi_adc_enable,
330 .disable = axi_adc_disable,
331 .data_format_set = axi_adc_data_format_set,
332 .chan_enable = axi_adc_chan_enable,
333 .chan_disable = axi_adc_chan_disable,
334 .request_buffer = axi_adc_request_buffer,
335 .free_buffer = axi_adc_free_buffer,
336 .data_sample_trigger = axi_adc_data_sample_trigger,
337 .iodelay_set = axi_adc_iodelays_set,
338 .test_pattern_set = axi_adc_test_pattern_set,
339 .chan_status = axi_adc_chan_status,
340 .debugfs_reg_access = iio_backend_debugfs_ptr(axi_adc_reg_access),
341 .debugfs_print_chan_status = iio_backend_debugfs_ptr(axi_adc_debugfs_print_chan_status),
342 };
343
344 static const struct iio_backend_info adi_axi_adc_generic = {
345 .name = "axi-adc",
346 .ops = &adi_axi_adc_ops,
347 };
348
adi_axi_adc_probe(struct platform_device * pdev)349 static int adi_axi_adc_probe(struct platform_device *pdev)
350 {
351 const unsigned int *expected_ver;
352 struct adi_axi_adc_state *st;
353 void __iomem *base;
354 unsigned int ver;
355 struct clk *clk;
356 int ret;
357
358 st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
359 if (!st)
360 return -ENOMEM;
361
362 base = devm_platform_ioremap_resource(pdev, 0);
363 if (IS_ERR(base))
364 return PTR_ERR(base);
365
366 st->dev = &pdev->dev;
367 st->regmap = devm_regmap_init_mmio(&pdev->dev, base,
368 &axi_adc_regmap_config);
369 if (IS_ERR(st->regmap))
370 return dev_err_probe(&pdev->dev, PTR_ERR(st->regmap),
371 "failed to init register map\n");
372
373 expected_ver = device_get_match_data(&pdev->dev);
374 if (!expected_ver)
375 return -ENODEV;
376
377 clk = devm_clk_get_enabled(&pdev->dev, NULL);
378 if (IS_ERR(clk))
379 return dev_err_probe(&pdev->dev, PTR_ERR(clk),
380 "failed to get clock\n");
381
382 /*
383 * Force disable the core. Up to the frontend to enable us. And we can
384 * still read/write registers...
385 */
386 ret = regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
387 if (ret)
388 return ret;
389
390 ret = regmap_read(st->regmap, ADI_AXI_REG_VERSION, &ver);
391 if (ret)
392 return ret;
393
394 if (ADI_AXI_PCORE_VER_MAJOR(ver) != ADI_AXI_PCORE_VER_MAJOR(*expected_ver)) {
395 dev_err(&pdev->dev,
396 "Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
397 ADI_AXI_PCORE_VER_MAJOR(*expected_ver),
398 ADI_AXI_PCORE_VER_MINOR(*expected_ver),
399 ADI_AXI_PCORE_VER_PATCH(*expected_ver),
400 ADI_AXI_PCORE_VER_MAJOR(ver),
401 ADI_AXI_PCORE_VER_MINOR(ver),
402 ADI_AXI_PCORE_VER_PATCH(ver));
403 return -ENODEV;
404 }
405
406 ret = devm_iio_backend_register(&pdev->dev, &adi_axi_adc_generic, st);
407 if (ret)
408 return dev_err_probe(&pdev->dev, ret,
409 "failed to register iio backend\n");
410
411 dev_info(&pdev->dev, "AXI ADC IP core (%d.%.2d.%c) probed\n",
412 ADI_AXI_PCORE_VER_MAJOR(ver),
413 ADI_AXI_PCORE_VER_MINOR(ver),
414 ADI_AXI_PCORE_VER_PATCH(ver));
415
416 return 0;
417 }
418
419 static unsigned int adi_axi_adc_10_0_a_info = ADI_AXI_PCORE_VER(10, 0, 'a');
420
421 /* Match table for of_platform binding */
422 static const struct of_device_id adi_axi_adc_of_match[] = {
423 { .compatible = "adi,axi-adc-10.0.a", .data = &adi_axi_adc_10_0_a_info },
424 { /* end of list */ }
425 };
426 MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);
427
428 static struct platform_driver adi_axi_adc_driver = {
429 .driver = {
430 .name = KBUILD_MODNAME,
431 .of_match_table = adi_axi_adc_of_match,
432 },
433 .probe = adi_axi_adc_probe,
434 };
435 module_platform_driver(adi_axi_adc_driver);
436
437 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
438 MODULE_DESCRIPTION("Analog Devices Generic AXI ADC IP core driver");
439 MODULE_LICENSE("GPL v2");
440 MODULE_IMPORT_NS("IIO_DMAENGINE_BUFFER");
441 MODULE_IMPORT_NS("IIO_BACKEND");
442