xref: /linux/drivers/iio/adc/xilinx-xadc-core.c (revision 8d6b3ea4d9eaca80982442b68a292ce50ce0a135)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Xilinx XADC driver
4  *
5  * Copyright 2013-2014 Analog Devices Inc.
6  *  Author: Lars-Peter Clausen <lars@metafoo.de>
7  *
8  * Documentation for the parts can be found at:
9  *  - XADC hardmacro: Xilinx UG480
10  *  - ZYNQ XADC interface: Xilinx UG585
11  *  - AXI XADC interface: Xilinx PG019
12  */
13 
14 #include <linux/clk.h>
15 #include <linux/device.h>
16 #include <linux/err.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/kernel.h>
20 #include <linux/mod_devicetable.h>
21 #include <linux/module.h>
22 #include <linux/overflow.h>
23 #include <linux/platform_device.h>
24 #include <linux/property.h>
25 #include <linux/slab.h>
26 #include <linux/sysfs.h>
27 
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/events.h>
30 #include <linux/iio/iio.h>
31 #include <linux/iio/sysfs.h>
32 #include <linux/iio/trigger.h>
33 #include <linux/iio/trigger_consumer.h>
34 #include <linux/iio/triggered_buffer.h>
35 
36 #include "xilinx-xadc.h"
37 
38 static const unsigned int XADC_ZYNQ_UNMASK_TIMEOUT = 500;
39 
40 /* ZYNQ register definitions */
41 #define XADC_ZYNQ_REG_CFG	0x00
42 #define XADC_ZYNQ_REG_INTSTS	0x04
43 #define XADC_ZYNQ_REG_INTMSK	0x08
44 #define XADC_ZYNQ_REG_STATUS	0x0c
45 #define XADC_ZYNQ_REG_CFIFO	0x10
46 #define XADC_ZYNQ_REG_DFIFO	0x14
47 #define XADC_ZYNQ_REG_CTL		0x18
48 
49 #define XADC_ZYNQ_CFG_ENABLE		BIT(31)
50 #define XADC_ZYNQ_CFG_CFIFOTH_MASK	(0xf << 20)
51 #define XADC_ZYNQ_CFG_CFIFOTH_OFFSET	20
52 #define XADC_ZYNQ_CFG_DFIFOTH_MASK	(0xf << 16)
53 #define XADC_ZYNQ_CFG_DFIFOTH_OFFSET	16
54 #define XADC_ZYNQ_CFG_WEDGE		BIT(13)
55 #define XADC_ZYNQ_CFG_REDGE		BIT(12)
56 #define XADC_ZYNQ_CFG_TCKRATE_MASK	(0x3 << 8)
57 #define XADC_ZYNQ_CFG_TCKRATE_DIV2	(0x0 << 8)
58 #define XADC_ZYNQ_CFG_TCKRATE_DIV4	(0x1 << 8)
59 #define XADC_ZYNQ_CFG_TCKRATE_DIV8	(0x2 << 8)
60 #define XADC_ZYNQ_CFG_TCKRATE_DIV16	(0x3 << 8)
61 #define XADC_ZYNQ_CFG_IGAP_MASK		0x1f
62 #define XADC_ZYNQ_CFG_IGAP(x)		(x)
63 
64 #define XADC_ZYNQ_INT_CFIFO_LTH		BIT(9)
65 #define XADC_ZYNQ_INT_DFIFO_GTH		BIT(8)
66 #define XADC_ZYNQ_INT_ALARM_MASK	0xff
67 #define XADC_ZYNQ_INT_ALARM_OFFSET	0
68 
69 #define XADC_ZYNQ_STATUS_CFIFO_LVL_MASK	(0xf << 16)
70 #define XADC_ZYNQ_STATUS_CFIFO_LVL_OFFSET	16
71 #define XADC_ZYNQ_STATUS_DFIFO_LVL_MASK	(0xf << 12)
72 #define XADC_ZYNQ_STATUS_DFIFO_LVL_OFFSET	12
73 #define XADC_ZYNQ_STATUS_CFIFOF		BIT(11)
74 #define XADC_ZYNQ_STATUS_CFIFOE		BIT(10)
75 #define XADC_ZYNQ_STATUS_DFIFOF		BIT(9)
76 #define XADC_ZYNQ_STATUS_DFIFOE		BIT(8)
77 #define XADC_ZYNQ_STATUS_OT		BIT(7)
78 #define XADC_ZYNQ_STATUS_ALM(x)		BIT(x)
79 
80 #define XADC_ZYNQ_CTL_RESET		BIT(4)
81 
82 #define XADC_ZYNQ_CMD_NOP		0x00
83 #define XADC_ZYNQ_CMD_READ		0x01
84 #define XADC_ZYNQ_CMD_WRITE		0x02
85 
86 #define XADC_ZYNQ_CMD(cmd, addr, data) (((cmd) << 26) | ((addr) << 16) | (data))
87 
88 /* AXI register definitions */
89 #define XADC_AXI_REG_RESET		0x00
90 #define XADC_AXI_REG_STATUS		0x04
91 #define XADC_AXI_REG_ALARM_STATUS	0x08
92 #define XADC_AXI_REG_CONVST		0x0c
93 #define XADC_AXI_REG_XADC_RESET		0x10
94 #define XADC_AXI_REG_GIER		0x5c
95 #define XADC_AXI_REG_IPISR		0x60
96 #define XADC_AXI_REG_IPIER		0x68
97 
98 /* 7 Series */
99 #define XADC_7S_AXI_ADC_REG_OFFSET	0x200
100 
101 /* UltraScale */
102 #define XADC_US_AXI_ADC_REG_OFFSET	0x400
103 
104 #define XADC_AXI_RESET_MAGIC		0xa
105 #define XADC_AXI_GIER_ENABLE		BIT(31)
106 
107 #define XADC_AXI_INT_EOS		BIT(4)
108 #define XADC_AXI_INT_ALARM_MASK		0x3c0f
109 
110 #define XADC_FLAGS_BUFFERED BIT(0)
111 #define XADC_FLAGS_IRQ_OPTIONAL BIT(1)
112 
113 /*
114  * The XADC hardware supports a samplerate of up to 1MSPS. Unfortunately it does
115  * not have a hardware FIFO. Which means an interrupt is generated for each
116  * conversion sequence. At 1MSPS sample rate the CPU in ZYNQ7000 is completely
117  * overloaded by the interrupts that it soft-lockups. For this reason the driver
118  * limits the maximum samplerate 150kSPS. At this rate the CPU is fairly busy,
119  * but still responsive.
120  */
121 #define XADC_MAX_SAMPLERATE 150000
122 
123 static void xadc_write_reg(struct xadc *xadc, unsigned int reg,
124 	uint32_t val)
125 {
126 	writel(val, xadc->base + reg);
127 }
128 
129 static void xadc_read_reg(struct xadc *xadc, unsigned int reg,
130 	uint32_t *val)
131 {
132 	*val = readl(xadc->base + reg);
133 }
134 
135 /*
136  * The ZYNQ interface uses two asynchronous FIFOs for communication with the
137  * XADC. Reads and writes to the XADC register are performed by submitting a
138  * request to the command FIFO (CFIFO), once the request has been completed the
139  * result can be read from the data FIFO (DFIFO). The method currently used in
140  * this driver is to submit the request for a read/write operation, then go to
141  * sleep and wait for an interrupt that signals that a response is available in
142  * the data FIFO.
143  */
144 
145 static void xadc_zynq_write_fifo(struct xadc *xadc, uint32_t *cmd,
146 	unsigned int n)
147 {
148 	unsigned int i;
149 
150 	for (i = 0; i < n; i++)
151 		xadc_write_reg(xadc, XADC_ZYNQ_REG_CFIFO, cmd[i]);
152 }
153 
154 static void xadc_zynq_drain_fifo(struct xadc *xadc)
155 {
156 	uint32_t status, tmp;
157 
158 	xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status);
159 
160 	while (!(status & XADC_ZYNQ_STATUS_DFIFOE)) {
161 		xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp);
162 		xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status);
163 	}
164 }
165 
166 static void xadc_zynq_update_intmsk(struct xadc *xadc, unsigned int mask,
167 	unsigned int val)
168 {
169 	xadc->zynq_intmask &= ~mask;
170 	xadc->zynq_intmask |= val;
171 
172 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK,
173 		xadc->zynq_intmask | xadc->zynq_masked_alarm);
174 }
175 
176 static int xadc_zynq_write_adc_reg(struct xadc *xadc, unsigned int reg,
177 	uint16_t val)
178 {
179 	uint32_t cmd[1];
180 	uint32_t tmp;
181 	int ret;
182 
183 	spin_lock_irq(&xadc->lock);
184 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
185 			XADC_ZYNQ_INT_DFIFO_GTH);
186 
187 	reinit_completion(&xadc->completion);
188 
189 	cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_WRITE, reg, val);
190 	xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd));
191 	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp);
192 	tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK;
193 	tmp |= 0 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET;
194 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp);
195 
196 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0);
197 	spin_unlock_irq(&xadc->lock);
198 
199 	ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ);
200 	if (ret == 0)
201 		ret = -EIO;
202 	else
203 		ret = 0;
204 
205 	xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp);
206 
207 	return ret;
208 }
209 
210 static int xadc_zynq_read_adc_reg(struct xadc *xadc, unsigned int reg,
211 	uint16_t *val)
212 {
213 	uint32_t cmd[2];
214 	uint32_t resp, tmp;
215 	int ret;
216 
217 	cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_READ, reg, 0);
218 	cmd[1] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_NOP, 0, 0);
219 
220 	spin_lock_irq(&xadc->lock);
221 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
222 			XADC_ZYNQ_INT_DFIFO_GTH);
223 	xadc_zynq_drain_fifo(xadc);
224 	reinit_completion(&xadc->completion);
225 
226 	xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd));
227 	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp);
228 	tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK;
229 	tmp |= 1 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET;
230 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp);
231 
232 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0);
233 	spin_unlock_irq(&xadc->lock);
234 	ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ);
235 	if (ret == 0)
236 		ret = -EIO;
237 	if (ret < 0)
238 		return ret;
239 
240 	xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp);
241 	xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp);
242 
243 	*val = resp & 0xffff;
244 
245 	return 0;
246 }
247 
248 static unsigned int xadc_zynq_transform_alarm(unsigned int alarm)
249 {
250 	return ((alarm & 0x80) >> 4) |
251 		((alarm & 0x78) << 1) |
252 		(alarm & 0x07);
253 }
254 
255 /*
256  * The ZYNQ threshold interrupts are level sensitive. Since we can't make the
257  * threshold condition go way from within the interrupt handler, this means as
258  * soon as a threshold condition is present we would enter the interrupt handler
259  * again and again. To work around this we mask all active thresholds interrupts
260  * in the interrupt handler and start a timer. In this timer we poll the
261  * interrupt status and only if the interrupt is inactive we unmask it again.
262  */
263 static void xadc_zynq_unmask_worker(struct work_struct *work)
264 {
265 	struct xadc *xadc = container_of(work, struct xadc, zynq_unmask_work.work);
266 	unsigned int misc_sts, unmask;
267 
268 	xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &misc_sts);
269 
270 	misc_sts &= XADC_ZYNQ_INT_ALARM_MASK;
271 
272 	spin_lock_irq(&xadc->lock);
273 
274 	/* Clear those bits which are not active anymore */
275 	unmask = (xadc->zynq_masked_alarm ^ misc_sts) & xadc->zynq_masked_alarm;
276 	xadc->zynq_masked_alarm &= misc_sts;
277 
278 	/* Also clear those which are masked out anyway */
279 	xadc->zynq_masked_alarm &= ~xadc->zynq_intmask;
280 
281 	/* Clear the interrupts before we unmask them */
282 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, unmask);
283 
284 	xadc_zynq_update_intmsk(xadc, 0, 0);
285 
286 	spin_unlock_irq(&xadc->lock);
287 
288 	/* if still pending some alarm re-trigger the timer */
289 	if (xadc->zynq_masked_alarm) {
290 		schedule_delayed_work(&xadc->zynq_unmask_work,
291 				msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT));
292 	}
293 
294 }
295 
296 static irqreturn_t xadc_zynq_interrupt_handler(int irq, void *devid)
297 {
298 	struct iio_dev *indio_dev = devid;
299 	struct xadc *xadc = iio_priv(indio_dev);
300 	uint32_t status;
301 
302 	xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
303 
304 	status &= ~(xadc->zynq_intmask | xadc->zynq_masked_alarm);
305 
306 	if (!status)
307 		return IRQ_NONE;
308 
309 	spin_lock(&xadc->lock);
310 
311 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status);
312 
313 	if (status & XADC_ZYNQ_INT_DFIFO_GTH) {
314 		xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
315 			XADC_ZYNQ_INT_DFIFO_GTH);
316 		complete(&xadc->completion);
317 	}
318 
319 	status &= XADC_ZYNQ_INT_ALARM_MASK;
320 	if (status) {
321 		xadc->zynq_masked_alarm |= status;
322 		/*
323 		 * mask the current event interrupt,
324 		 * unmask it when the interrupt is no more active.
325 		 */
326 		xadc_zynq_update_intmsk(xadc, 0, 0);
327 
328 		xadc_handle_events(indio_dev,
329 				xadc_zynq_transform_alarm(status));
330 
331 		/* unmask the required interrupts in timer. */
332 		schedule_delayed_work(&xadc->zynq_unmask_work,
333 				msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT));
334 	}
335 	spin_unlock(&xadc->lock);
336 
337 	return IRQ_HANDLED;
338 }
339 
340 #define XADC_ZYNQ_TCK_RATE_MAX 50000000
341 #define XADC_ZYNQ_IGAP_DEFAULT 20
342 #define XADC_ZYNQ_PCAP_RATE_MAX 200000000
343 
344 static int xadc_zynq_setup(struct platform_device *pdev,
345 	struct iio_dev *indio_dev, int irq)
346 {
347 	struct xadc *xadc = iio_priv(indio_dev);
348 	unsigned long pcap_rate;
349 	unsigned int tck_div;
350 	unsigned int div;
351 	unsigned int igap;
352 	unsigned int tck_rate;
353 	int ret;
354 
355 	/* TODO: Figure out how to make igap and tck_rate configurable */
356 	igap = XADC_ZYNQ_IGAP_DEFAULT;
357 	tck_rate = XADC_ZYNQ_TCK_RATE_MAX;
358 
359 	xadc->zynq_intmask = ~0;
360 
361 	pcap_rate = clk_get_rate(xadc->clk);
362 	if (!pcap_rate)
363 		return -EINVAL;
364 
365 	if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) {
366 		ret = clk_set_rate(xadc->clk,
367 				   (unsigned long)XADC_ZYNQ_PCAP_RATE_MAX);
368 		if (ret)
369 			return ret;
370 	}
371 
372 	if (tck_rate > pcap_rate / 2) {
373 		div = 2;
374 	} else {
375 		div = pcap_rate / tck_rate;
376 		if (pcap_rate / div > XADC_ZYNQ_TCK_RATE_MAX)
377 			div++;
378 	}
379 
380 	if (div <= 3)
381 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV2;
382 	else if (div <= 7)
383 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV4;
384 	else if (div <= 15)
385 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV8;
386 	else
387 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV16;
388 
389 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, XADC_ZYNQ_CTL_RESET);
390 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, 0);
391 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, ~0);
392 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK, xadc->zynq_intmask);
393 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, XADC_ZYNQ_CFG_ENABLE |
394 			XADC_ZYNQ_CFG_REDGE | XADC_ZYNQ_CFG_WEDGE |
395 			tck_div | XADC_ZYNQ_CFG_IGAP(igap));
396 
397 	if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) {
398 		ret = clk_set_rate(xadc->clk, pcap_rate);
399 		if (ret)
400 			return ret;
401 	}
402 
403 	return 0;
404 }
405 
406 static unsigned long xadc_zynq_get_dclk_rate(struct xadc *xadc)
407 {
408 	unsigned int div;
409 	uint32_t val;
410 
411 	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &val);
412 
413 	switch (val & XADC_ZYNQ_CFG_TCKRATE_MASK) {
414 	case XADC_ZYNQ_CFG_TCKRATE_DIV4:
415 		div = 4;
416 		break;
417 	case XADC_ZYNQ_CFG_TCKRATE_DIV8:
418 		div = 8;
419 		break;
420 	case XADC_ZYNQ_CFG_TCKRATE_DIV16:
421 		div = 16;
422 		break;
423 	default:
424 		div = 2;
425 		break;
426 	}
427 
428 	return clk_get_rate(xadc->clk) / div;
429 }
430 
431 static void xadc_zynq_update_alarm(struct xadc *xadc, unsigned int alarm)
432 {
433 	unsigned long flags;
434 	uint32_t status;
435 
436 	/* Move OT to bit 7 */
437 	alarm = ((alarm & 0x08) << 4) | ((alarm & 0xf0) >> 1) | (alarm & 0x07);
438 
439 	spin_lock_irqsave(&xadc->lock, flags);
440 
441 	/* Clear previous interrupts if any. */
442 	xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
443 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status & alarm);
444 
445 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_ALARM_MASK,
446 		~alarm & XADC_ZYNQ_INT_ALARM_MASK);
447 
448 	spin_unlock_irqrestore(&xadc->lock, flags);
449 }
450 
451 static const struct xadc_ops xadc_zynq_ops = {
452 	.read = xadc_zynq_read_adc_reg,
453 	.write = xadc_zynq_write_adc_reg,
454 	.setup = xadc_zynq_setup,
455 	.get_dclk_rate = xadc_zynq_get_dclk_rate,
456 	.interrupt_handler = xadc_zynq_interrupt_handler,
457 	.update_alarm = xadc_zynq_update_alarm,
458 	.type = XADC_TYPE_S7,
459 };
460 
461 static const unsigned int xadc_axi_reg_offsets[] = {
462 	[XADC_TYPE_S7] = XADC_7S_AXI_ADC_REG_OFFSET,
463 	[XADC_TYPE_US] = XADC_US_AXI_ADC_REG_OFFSET,
464 };
465 
466 static int xadc_axi_read_adc_reg(struct xadc *xadc, unsigned int reg,
467 	uint16_t *val)
468 {
469 	uint32_t val32;
470 
471 	xadc_read_reg(xadc, xadc_axi_reg_offsets[xadc->ops->type] + reg * 4,
472 		&val32);
473 	*val = val32 & 0xffff;
474 
475 	return 0;
476 }
477 
478 static int xadc_axi_write_adc_reg(struct xadc *xadc, unsigned int reg,
479 	uint16_t val)
480 {
481 	xadc_write_reg(xadc, xadc_axi_reg_offsets[xadc->ops->type] + reg * 4,
482 		val);
483 
484 	return 0;
485 }
486 
487 static int xadc_axi_setup(struct platform_device *pdev,
488 	struct iio_dev *indio_dev, int irq)
489 {
490 	struct xadc *xadc = iio_priv(indio_dev);
491 
492 	xadc_write_reg(xadc, XADC_AXI_REG_RESET, XADC_AXI_RESET_MAGIC);
493 	xadc_write_reg(xadc, XADC_AXI_REG_GIER, XADC_AXI_GIER_ENABLE);
494 
495 	return 0;
496 }
497 
498 static irqreturn_t xadc_axi_interrupt_handler(int irq, void *devid)
499 {
500 	struct iio_dev *indio_dev = devid;
501 	struct xadc *xadc = iio_priv(indio_dev);
502 	uint32_t status, mask;
503 	unsigned int events;
504 
505 	xadc_read_reg(xadc, XADC_AXI_REG_IPISR, &status);
506 	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &mask);
507 	status &= mask;
508 
509 	if (!status)
510 		return IRQ_NONE;
511 
512 	if ((status & XADC_AXI_INT_EOS) && xadc->trigger)
513 		iio_trigger_poll(xadc->trigger);
514 
515 	if (status & XADC_AXI_INT_ALARM_MASK) {
516 		/*
517 		 * The order of the bits in the AXI-XADC status register does
518 		 * not match the order of the bits in the XADC alarm enable
519 		 * register. xadc_handle_events() expects the events to be in
520 		 * the same order as the XADC alarm enable register.
521 		 */
522 		events = (status & 0x000e) >> 1;
523 		events |= (status & 0x0001) << 3;
524 		events |= (status & 0x3c00) >> 6;
525 		xadc_handle_events(indio_dev, events);
526 	}
527 
528 	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, status);
529 
530 	return IRQ_HANDLED;
531 }
532 
533 static void xadc_axi_update_alarm(struct xadc *xadc, unsigned int alarm)
534 {
535 	uint32_t val;
536 	unsigned long flags;
537 
538 	/*
539 	 * The order of the bits in the AXI-XADC status register does not match
540 	 * the order of the bits in the XADC alarm enable register. We get
541 	 * passed the alarm mask in the same order as in the XADC alarm enable
542 	 * register.
543 	 */
544 	alarm = ((alarm & 0x07) << 1) | ((alarm & 0x08) >> 3) |
545 			((alarm & 0xf0) << 6);
546 
547 	spin_lock_irqsave(&xadc->lock, flags);
548 	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
549 	val &= ~XADC_AXI_INT_ALARM_MASK;
550 	val |= alarm;
551 	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
552 	spin_unlock_irqrestore(&xadc->lock, flags);
553 }
554 
555 static unsigned long xadc_axi_get_dclk(struct xadc *xadc)
556 {
557 	return clk_get_rate(xadc->clk);
558 }
559 
560 static const struct xadc_ops xadc_7s_axi_ops = {
561 	.read = xadc_axi_read_adc_reg,
562 	.write = xadc_axi_write_adc_reg,
563 	.setup = xadc_axi_setup,
564 	.get_dclk_rate = xadc_axi_get_dclk,
565 	.update_alarm = xadc_axi_update_alarm,
566 	.interrupt_handler = xadc_axi_interrupt_handler,
567 	.flags = XADC_FLAGS_BUFFERED | XADC_FLAGS_IRQ_OPTIONAL,
568 	.type = XADC_TYPE_S7,
569 };
570 
571 static const struct xadc_ops xadc_us_axi_ops = {
572 	.read = xadc_axi_read_adc_reg,
573 	.write = xadc_axi_write_adc_reg,
574 	.setup = xadc_axi_setup,
575 	.get_dclk_rate = xadc_axi_get_dclk,
576 	.update_alarm = xadc_axi_update_alarm,
577 	.interrupt_handler = xadc_axi_interrupt_handler,
578 	.flags = XADC_FLAGS_BUFFERED | XADC_FLAGS_IRQ_OPTIONAL,
579 	.type = XADC_TYPE_US,
580 };
581 
582 static int _xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
583 	uint16_t mask, uint16_t val)
584 {
585 	uint16_t tmp;
586 	int ret;
587 
588 	ret = _xadc_read_adc_reg(xadc, reg, &tmp);
589 	if (ret)
590 		return ret;
591 
592 	return _xadc_write_adc_reg(xadc, reg, (tmp & ~mask) | val);
593 }
594 
595 static int xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
596 	uint16_t mask, uint16_t val)
597 {
598 	int ret;
599 
600 	mutex_lock(&xadc->mutex);
601 	ret = _xadc_update_adc_reg(xadc, reg, mask, val);
602 	mutex_unlock(&xadc->mutex);
603 
604 	return ret;
605 }
606 
607 static unsigned long xadc_get_dclk_rate(struct xadc *xadc)
608 {
609 	return xadc->ops->get_dclk_rate(xadc);
610 }
611 
612 static int xadc_update_scan_mode(struct iio_dev *indio_dev,
613 	const unsigned long *mask)
614 {
615 	struct xadc *xadc = iio_priv(indio_dev);
616 	size_t n;
617 	void *data;
618 
619 	n = bitmap_weight(mask, indio_dev->masklength);
620 
621 	data = devm_krealloc_array(indio_dev->dev.parent, xadc->data,
622 				   n, sizeof(*xadc->data), GFP_KERNEL);
623 	if (!data)
624 		return -ENOMEM;
625 
626 	memset(data, 0, n * sizeof(*xadc->data));
627 	xadc->data = data;
628 
629 	return 0;
630 }
631 
632 static unsigned int xadc_scan_index_to_channel(unsigned int scan_index)
633 {
634 	switch (scan_index) {
635 	case 5:
636 		return XADC_REG_VCCPINT;
637 	case 6:
638 		return XADC_REG_VCCPAUX;
639 	case 7:
640 		return XADC_REG_VCCO_DDR;
641 	case 8:
642 		return XADC_REG_TEMP;
643 	case 9:
644 		return XADC_REG_VCCINT;
645 	case 10:
646 		return XADC_REG_VCCAUX;
647 	case 11:
648 		return XADC_REG_VPVN;
649 	case 12:
650 		return XADC_REG_VREFP;
651 	case 13:
652 		return XADC_REG_VREFN;
653 	case 14:
654 		return XADC_REG_VCCBRAM;
655 	default:
656 		return XADC_REG_VAUX(scan_index - 16);
657 	}
658 }
659 
660 static irqreturn_t xadc_trigger_handler(int irq, void *p)
661 {
662 	struct iio_poll_func *pf = p;
663 	struct iio_dev *indio_dev = pf->indio_dev;
664 	struct xadc *xadc = iio_priv(indio_dev);
665 	unsigned int chan;
666 	int i, j;
667 
668 	if (!xadc->data)
669 		goto out;
670 
671 	j = 0;
672 	for_each_set_bit(i, indio_dev->active_scan_mask,
673 		indio_dev->masklength) {
674 		chan = xadc_scan_index_to_channel(i);
675 		xadc_read_adc_reg(xadc, chan, &xadc->data[j]);
676 		j++;
677 	}
678 
679 	iio_push_to_buffers(indio_dev, xadc->data);
680 
681 out:
682 	iio_trigger_notify_done(indio_dev->trig);
683 
684 	return IRQ_HANDLED;
685 }
686 
687 static int xadc_trigger_set_state(struct iio_trigger *trigger, bool state)
688 {
689 	struct xadc *xadc = iio_trigger_get_drvdata(trigger);
690 	unsigned long flags;
691 	unsigned int convst;
692 	unsigned int val;
693 	int ret = 0;
694 
695 	mutex_lock(&xadc->mutex);
696 
697 	if (state) {
698 		/* Only one of the two triggers can be active at a time. */
699 		if (xadc->trigger != NULL) {
700 			ret = -EBUSY;
701 			goto err_out;
702 		} else {
703 			xadc->trigger = trigger;
704 			if (trigger == xadc->convst_trigger)
705 				convst = XADC_CONF0_EC;
706 			else
707 				convst = 0;
708 		}
709 		ret = _xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF0_EC,
710 					convst);
711 		if (ret)
712 			goto err_out;
713 	} else {
714 		xadc->trigger = NULL;
715 	}
716 
717 	spin_lock_irqsave(&xadc->lock, flags);
718 	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
719 	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, XADC_AXI_INT_EOS);
720 	if (state)
721 		val |= XADC_AXI_INT_EOS;
722 	else
723 		val &= ~XADC_AXI_INT_EOS;
724 	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
725 	spin_unlock_irqrestore(&xadc->lock, flags);
726 
727 err_out:
728 	mutex_unlock(&xadc->mutex);
729 
730 	return ret;
731 }
732 
733 static const struct iio_trigger_ops xadc_trigger_ops = {
734 	.set_trigger_state = &xadc_trigger_set_state,
735 };
736 
737 static struct iio_trigger *xadc_alloc_trigger(struct iio_dev *indio_dev,
738 	const char *name)
739 {
740 	struct device *dev = indio_dev->dev.parent;
741 	struct iio_trigger *trig;
742 	int ret;
743 
744 	trig = devm_iio_trigger_alloc(dev, "%s%d-%s", indio_dev->name,
745 				      iio_device_id(indio_dev), name);
746 	if (trig == NULL)
747 		return ERR_PTR(-ENOMEM);
748 
749 	trig->ops = &xadc_trigger_ops;
750 	iio_trigger_set_drvdata(trig, iio_priv(indio_dev));
751 
752 	ret = devm_iio_trigger_register(dev, trig);
753 	if (ret)
754 		return ERR_PTR(ret);
755 
756 	return trig;
757 }
758 
759 static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode)
760 {
761 	uint16_t val;
762 
763 	/*
764 	 * As per datasheet the power-down bits are don't care in the
765 	 * UltraScale, but as per reality setting the power-down bit for the
766 	 * non-existing ADC-B powers down the main ADC, so just return and don't
767 	 * do anything.
768 	 */
769 	if (xadc->ops->type == XADC_TYPE_US)
770 		return 0;
771 
772 	/* Powerdown the ADC-B when it is not needed. */
773 	switch (seq_mode) {
774 	case XADC_CONF1_SEQ_SIMULTANEOUS:
775 	case XADC_CONF1_SEQ_INDEPENDENT:
776 		val = 0;
777 		break;
778 	default:
779 		val = XADC_CONF2_PD_ADC_B;
780 		break;
781 	}
782 
783 	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_PD_MASK,
784 		val);
785 }
786 
787 static int xadc_get_seq_mode(struct xadc *xadc, unsigned long scan_mode)
788 {
789 	unsigned int aux_scan_mode = scan_mode >> 16;
790 
791 	/* UltraScale has only one ADC and supports only continuous mode */
792 	if (xadc->ops->type == XADC_TYPE_US)
793 		return XADC_CONF1_SEQ_CONTINUOUS;
794 
795 	if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_DUAL)
796 		return XADC_CONF1_SEQ_SIMULTANEOUS;
797 
798 	if ((aux_scan_mode & 0xff00) == 0 ||
799 		(aux_scan_mode & 0x00ff) == 0)
800 		return XADC_CONF1_SEQ_CONTINUOUS;
801 
802 	return XADC_CONF1_SEQ_SIMULTANEOUS;
803 }
804 
805 static int xadc_postdisable(struct iio_dev *indio_dev)
806 {
807 	struct xadc *xadc = iio_priv(indio_dev);
808 	unsigned long scan_mask;
809 	int ret;
810 	int i;
811 
812 	scan_mask = 1; /* Run calibration as part of the sequence */
813 	for (i = 0; i < indio_dev->num_channels; i++)
814 		scan_mask |= BIT(indio_dev->channels[i].scan_index);
815 
816 	/* Enable all channels and calibration */
817 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
818 	if (ret)
819 		return ret;
820 
821 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
822 	if (ret)
823 		return ret;
824 
825 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
826 		XADC_CONF1_SEQ_CONTINUOUS);
827 	if (ret)
828 		return ret;
829 
830 	return xadc_power_adc_b(xadc, XADC_CONF1_SEQ_CONTINUOUS);
831 }
832 
833 static int xadc_preenable(struct iio_dev *indio_dev)
834 {
835 	struct xadc *xadc = iio_priv(indio_dev);
836 	unsigned long scan_mask;
837 	int seq_mode;
838 	int ret;
839 
840 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
841 		XADC_CONF1_SEQ_DEFAULT);
842 	if (ret)
843 		goto err;
844 
845 	scan_mask = *indio_dev->active_scan_mask;
846 	seq_mode = xadc_get_seq_mode(xadc, scan_mask);
847 
848 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
849 	if (ret)
850 		goto err;
851 
852 	/*
853 	 * In simultaneous mode the upper and lower aux channels are samples at
854 	 * the same time. In this mode the upper 8 bits in the sequencer
855 	 * register are don't care and the lower 8 bits control two channels
856 	 * each. As such we must set the bit if either the channel in the lower
857 	 * group or the upper group is enabled.
858 	 */
859 	if (seq_mode == XADC_CONF1_SEQ_SIMULTANEOUS)
860 		scan_mask = ((scan_mask >> 8) | scan_mask) & 0xff0000;
861 
862 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
863 	if (ret)
864 		goto err;
865 
866 	ret = xadc_power_adc_b(xadc, seq_mode);
867 	if (ret)
868 		goto err;
869 
870 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
871 		seq_mode);
872 	if (ret)
873 		goto err;
874 
875 	return 0;
876 err:
877 	xadc_postdisable(indio_dev);
878 	return ret;
879 }
880 
881 static const struct iio_buffer_setup_ops xadc_buffer_ops = {
882 	.preenable = &xadc_preenable,
883 	.postdisable = &xadc_postdisable,
884 };
885 
886 static int xadc_read_samplerate(struct xadc *xadc)
887 {
888 	unsigned int div;
889 	uint16_t val16;
890 	int ret;
891 
892 	ret = xadc_read_adc_reg(xadc, XADC_REG_CONF2, &val16);
893 	if (ret)
894 		return ret;
895 
896 	div = (val16 & XADC_CONF2_DIV_MASK) >> XADC_CONF2_DIV_OFFSET;
897 	if (div < 2)
898 		div = 2;
899 
900 	return xadc_get_dclk_rate(xadc) / div / 26;
901 }
902 
903 static int xadc_read_raw(struct iio_dev *indio_dev,
904 	struct iio_chan_spec const *chan, int *val, int *val2, long info)
905 {
906 	struct xadc *xadc = iio_priv(indio_dev);
907 	unsigned int bits = chan->scan_type.realbits;
908 	uint16_t val16;
909 	int ret;
910 
911 	switch (info) {
912 	case IIO_CHAN_INFO_RAW:
913 		if (iio_buffer_enabled(indio_dev))
914 			return -EBUSY;
915 		ret = xadc_read_adc_reg(xadc, chan->address, &val16);
916 		if (ret < 0)
917 			return ret;
918 
919 		val16 >>= chan->scan_type.shift;
920 		if (chan->scan_type.sign == 'u')
921 			*val = val16;
922 		else
923 			*val = sign_extend32(val16, bits - 1);
924 
925 		return IIO_VAL_INT;
926 	case IIO_CHAN_INFO_SCALE:
927 		switch (chan->type) {
928 		case IIO_VOLTAGE:
929 			/* V = (val * 3.0) / 2**bits */
930 			switch (chan->address) {
931 			case XADC_REG_VCCINT:
932 			case XADC_REG_VCCAUX:
933 			case XADC_REG_VREFP:
934 			case XADC_REG_VREFN:
935 			case XADC_REG_VCCBRAM:
936 			case XADC_REG_VCCPINT:
937 			case XADC_REG_VCCPAUX:
938 			case XADC_REG_VCCO_DDR:
939 				*val = 3000;
940 				break;
941 			default:
942 				*val = 1000;
943 				break;
944 			}
945 			*val2 = bits;
946 			return IIO_VAL_FRACTIONAL_LOG2;
947 		case IIO_TEMP:
948 			/* Temp in C = (val * 503.975) / 2**bits - 273.15 */
949 			*val = 503975;
950 			*val2 = bits;
951 			return IIO_VAL_FRACTIONAL_LOG2;
952 		default:
953 			return -EINVAL;
954 		}
955 	case IIO_CHAN_INFO_OFFSET:
956 		/* Only the temperature channel has an offset */
957 		*val = -((273150 << bits) / 503975);
958 		return IIO_VAL_INT;
959 	case IIO_CHAN_INFO_SAMP_FREQ:
960 		ret = xadc_read_samplerate(xadc);
961 		if (ret < 0)
962 			return ret;
963 
964 		*val = ret;
965 		return IIO_VAL_INT;
966 	default:
967 		return -EINVAL;
968 	}
969 }
970 
971 static int xadc_write_samplerate(struct xadc *xadc, int val)
972 {
973 	unsigned long clk_rate = xadc_get_dclk_rate(xadc);
974 	unsigned int div;
975 
976 	if (!clk_rate)
977 		return -EINVAL;
978 
979 	if (val <= 0)
980 		return -EINVAL;
981 
982 	/* Max. 150 kSPS */
983 	if (val > XADC_MAX_SAMPLERATE)
984 		val = XADC_MAX_SAMPLERATE;
985 
986 	val *= 26;
987 
988 	/* Min 1MHz */
989 	if (val < 1000000)
990 		val = 1000000;
991 
992 	/*
993 	 * We want to round down, but only if we do not exceed the 150 kSPS
994 	 * limit.
995 	 */
996 	div = clk_rate / val;
997 	if (clk_rate / div / 26 > XADC_MAX_SAMPLERATE)
998 		div++;
999 	if (div < 2)
1000 		div = 2;
1001 	else if (div > 0xff)
1002 		div = 0xff;
1003 
1004 	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_DIV_MASK,
1005 		div << XADC_CONF2_DIV_OFFSET);
1006 }
1007 
1008 static int xadc_write_raw(struct iio_dev *indio_dev,
1009 	struct iio_chan_spec const *chan, int val, int val2, long info)
1010 {
1011 	struct xadc *xadc = iio_priv(indio_dev);
1012 
1013 	if (info != IIO_CHAN_INFO_SAMP_FREQ)
1014 		return -EINVAL;
1015 
1016 	return xadc_write_samplerate(xadc, val);
1017 }
1018 
1019 static const struct iio_event_spec xadc_temp_events[] = {
1020 	{
1021 		.type = IIO_EV_TYPE_THRESH,
1022 		.dir = IIO_EV_DIR_RISING,
1023 		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
1024 				BIT(IIO_EV_INFO_VALUE) |
1025 				BIT(IIO_EV_INFO_HYSTERESIS),
1026 	},
1027 };
1028 
1029 /* Separate values for upper and lower thresholds, but only a shared enabled */
1030 static const struct iio_event_spec xadc_voltage_events[] = {
1031 	{
1032 		.type = IIO_EV_TYPE_THRESH,
1033 		.dir = IIO_EV_DIR_RISING,
1034 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
1035 	}, {
1036 		.type = IIO_EV_TYPE_THRESH,
1037 		.dir = IIO_EV_DIR_FALLING,
1038 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
1039 	}, {
1040 		.type = IIO_EV_TYPE_THRESH,
1041 		.dir = IIO_EV_DIR_EITHER,
1042 		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
1043 	},
1044 };
1045 
1046 #define XADC_CHAN_TEMP(_chan, _scan_index, _addr, _bits) { \
1047 	.type = IIO_TEMP, \
1048 	.indexed = 1, \
1049 	.channel = (_chan), \
1050 	.address = (_addr), \
1051 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
1052 		BIT(IIO_CHAN_INFO_SCALE) | \
1053 		BIT(IIO_CHAN_INFO_OFFSET), \
1054 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
1055 	.event_spec = xadc_temp_events, \
1056 	.num_event_specs = ARRAY_SIZE(xadc_temp_events), \
1057 	.scan_index = (_scan_index), \
1058 	.scan_type = { \
1059 		.sign = 'u', \
1060 		.realbits = (_bits), \
1061 		.storagebits = 16, \
1062 		.shift = 16 - (_bits), \
1063 		.endianness = IIO_CPU, \
1064 	}, \
1065 }
1066 
1067 #define XADC_CHAN_VOLTAGE(_chan, _scan_index, _addr, _bits, _ext, _alarm) { \
1068 	.type = IIO_VOLTAGE, \
1069 	.indexed = 1, \
1070 	.channel = (_chan), \
1071 	.address = (_addr), \
1072 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
1073 		BIT(IIO_CHAN_INFO_SCALE), \
1074 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
1075 	.event_spec = (_alarm) ? xadc_voltage_events : NULL, \
1076 	.num_event_specs = (_alarm) ? ARRAY_SIZE(xadc_voltage_events) : 0, \
1077 	.scan_index = (_scan_index), \
1078 	.scan_type = { \
1079 		.sign = ((_addr) == XADC_REG_VREFN) ? 's' : 'u', \
1080 		.realbits = (_bits), \
1081 		.storagebits = 16, \
1082 		.shift = 16 - (_bits), \
1083 		.endianness = IIO_CPU, \
1084 	}, \
1085 	.extend_name = _ext, \
1086 }
1087 
1088 /* 7 Series */
1089 #define XADC_7S_CHAN_TEMP(_chan, _scan_index, _addr) \
1090 	XADC_CHAN_TEMP(_chan, _scan_index, _addr, 12)
1091 #define XADC_7S_CHAN_VOLTAGE(_chan, _scan_index, _addr, _ext, _alarm) \
1092 	XADC_CHAN_VOLTAGE(_chan, _scan_index, _addr, 12, _ext, _alarm)
1093 
1094 static const struct iio_chan_spec xadc_7s_channels[] = {
1095 	XADC_7S_CHAN_TEMP(0, 8, XADC_REG_TEMP),
1096 	XADC_7S_CHAN_VOLTAGE(0, 9, XADC_REG_VCCINT, "vccint", true),
1097 	XADC_7S_CHAN_VOLTAGE(1, 10, XADC_REG_VCCAUX, "vccaux", true),
1098 	XADC_7S_CHAN_VOLTAGE(2, 14, XADC_REG_VCCBRAM, "vccbram", true),
1099 	XADC_7S_CHAN_VOLTAGE(3, 5, XADC_REG_VCCPINT, "vccpint", true),
1100 	XADC_7S_CHAN_VOLTAGE(4, 6, XADC_REG_VCCPAUX, "vccpaux", true),
1101 	XADC_7S_CHAN_VOLTAGE(5, 7, XADC_REG_VCCO_DDR, "vccoddr", true),
1102 	XADC_7S_CHAN_VOLTAGE(6, 12, XADC_REG_VREFP, "vrefp", false),
1103 	XADC_7S_CHAN_VOLTAGE(7, 13, XADC_REG_VREFN, "vrefn", false),
1104 	XADC_7S_CHAN_VOLTAGE(8, 11, XADC_REG_VPVN, NULL, false),
1105 	XADC_7S_CHAN_VOLTAGE(9, 16, XADC_REG_VAUX(0), NULL, false),
1106 	XADC_7S_CHAN_VOLTAGE(10, 17, XADC_REG_VAUX(1), NULL, false),
1107 	XADC_7S_CHAN_VOLTAGE(11, 18, XADC_REG_VAUX(2), NULL, false),
1108 	XADC_7S_CHAN_VOLTAGE(12, 19, XADC_REG_VAUX(3), NULL, false),
1109 	XADC_7S_CHAN_VOLTAGE(13, 20, XADC_REG_VAUX(4), NULL, false),
1110 	XADC_7S_CHAN_VOLTAGE(14, 21, XADC_REG_VAUX(5), NULL, false),
1111 	XADC_7S_CHAN_VOLTAGE(15, 22, XADC_REG_VAUX(6), NULL, false),
1112 	XADC_7S_CHAN_VOLTAGE(16, 23, XADC_REG_VAUX(7), NULL, false),
1113 	XADC_7S_CHAN_VOLTAGE(17, 24, XADC_REG_VAUX(8), NULL, false),
1114 	XADC_7S_CHAN_VOLTAGE(18, 25, XADC_REG_VAUX(9), NULL, false),
1115 	XADC_7S_CHAN_VOLTAGE(19, 26, XADC_REG_VAUX(10), NULL, false),
1116 	XADC_7S_CHAN_VOLTAGE(20, 27, XADC_REG_VAUX(11), NULL, false),
1117 	XADC_7S_CHAN_VOLTAGE(21, 28, XADC_REG_VAUX(12), NULL, false),
1118 	XADC_7S_CHAN_VOLTAGE(22, 29, XADC_REG_VAUX(13), NULL, false),
1119 	XADC_7S_CHAN_VOLTAGE(23, 30, XADC_REG_VAUX(14), NULL, false),
1120 	XADC_7S_CHAN_VOLTAGE(24, 31, XADC_REG_VAUX(15), NULL, false),
1121 };
1122 
1123 /* UltraScale */
1124 #define XADC_US_CHAN_TEMP(_chan, _scan_index, _addr) \
1125 	XADC_CHAN_TEMP(_chan, _scan_index, _addr, 10)
1126 #define XADC_US_CHAN_VOLTAGE(_chan, _scan_index, _addr, _ext, _alarm) \
1127 	XADC_CHAN_VOLTAGE(_chan, _scan_index, _addr, 10, _ext, _alarm)
1128 
1129 static const struct iio_chan_spec xadc_us_channels[] = {
1130 	XADC_US_CHAN_TEMP(0, 8, XADC_REG_TEMP),
1131 	XADC_US_CHAN_VOLTAGE(0, 9, XADC_REG_VCCINT, "vccint", true),
1132 	XADC_US_CHAN_VOLTAGE(1, 10, XADC_REG_VCCAUX, "vccaux", true),
1133 	XADC_US_CHAN_VOLTAGE(2, 14, XADC_REG_VCCBRAM, "vccbram", true),
1134 	XADC_US_CHAN_VOLTAGE(3, 5, XADC_REG_VCCPINT, "vccpsintlp", true),
1135 	XADC_US_CHAN_VOLTAGE(4, 6, XADC_REG_VCCPAUX, "vccpsintfp", true),
1136 	XADC_US_CHAN_VOLTAGE(5, 7, XADC_REG_VCCO_DDR, "vccpsaux", true),
1137 	XADC_US_CHAN_VOLTAGE(6, 12, XADC_REG_VREFP, "vrefp", false),
1138 	XADC_US_CHAN_VOLTAGE(7, 13, XADC_REG_VREFN, "vrefn", false),
1139 	XADC_US_CHAN_VOLTAGE(8, 11, XADC_REG_VPVN, NULL, false),
1140 	XADC_US_CHAN_VOLTAGE(9, 16, XADC_REG_VAUX(0), NULL, false),
1141 	XADC_US_CHAN_VOLTAGE(10, 17, XADC_REG_VAUX(1), NULL, false),
1142 	XADC_US_CHAN_VOLTAGE(11, 18, XADC_REG_VAUX(2), NULL, false),
1143 	XADC_US_CHAN_VOLTAGE(12, 19, XADC_REG_VAUX(3), NULL, false),
1144 	XADC_US_CHAN_VOLTAGE(13, 20, XADC_REG_VAUX(4), NULL, false),
1145 	XADC_US_CHAN_VOLTAGE(14, 21, XADC_REG_VAUX(5), NULL, false),
1146 	XADC_US_CHAN_VOLTAGE(15, 22, XADC_REG_VAUX(6), NULL, false),
1147 	XADC_US_CHAN_VOLTAGE(16, 23, XADC_REG_VAUX(7), NULL, false),
1148 	XADC_US_CHAN_VOLTAGE(17, 24, XADC_REG_VAUX(8), NULL, false),
1149 	XADC_US_CHAN_VOLTAGE(18, 25, XADC_REG_VAUX(9), NULL, false),
1150 	XADC_US_CHAN_VOLTAGE(19, 26, XADC_REG_VAUX(10), NULL, false),
1151 	XADC_US_CHAN_VOLTAGE(20, 27, XADC_REG_VAUX(11), NULL, false),
1152 	XADC_US_CHAN_VOLTAGE(21, 28, XADC_REG_VAUX(12), NULL, false),
1153 	XADC_US_CHAN_VOLTAGE(22, 29, XADC_REG_VAUX(13), NULL, false),
1154 	XADC_US_CHAN_VOLTAGE(23, 30, XADC_REG_VAUX(14), NULL, false),
1155 	XADC_US_CHAN_VOLTAGE(24, 31, XADC_REG_VAUX(15), NULL, false),
1156 };
1157 
1158 static const struct iio_info xadc_info = {
1159 	.read_raw = &xadc_read_raw,
1160 	.write_raw = &xadc_write_raw,
1161 	.read_event_config = &xadc_read_event_config,
1162 	.write_event_config = &xadc_write_event_config,
1163 	.read_event_value = &xadc_read_event_value,
1164 	.write_event_value = &xadc_write_event_value,
1165 	.update_scan_mode = &xadc_update_scan_mode,
1166 };
1167 
1168 static const struct of_device_id xadc_of_match_table[] = {
1169 	{
1170 		.compatible = "xlnx,zynq-xadc-1.00.a",
1171 		.data = &xadc_zynq_ops
1172 	}, {
1173 		.compatible = "xlnx,axi-xadc-1.00.a",
1174 		.data = &xadc_7s_axi_ops
1175 	}, {
1176 		.compatible = "xlnx,system-management-wiz-1.3",
1177 		.data = &xadc_us_axi_ops
1178 	},
1179 	{ },
1180 };
1181 MODULE_DEVICE_TABLE(of, xadc_of_match_table);
1182 
1183 static int xadc_parse_dt(struct iio_dev *indio_dev, unsigned int *conf, int irq)
1184 {
1185 	struct device *dev = indio_dev->dev.parent;
1186 	struct xadc *xadc = iio_priv(indio_dev);
1187 	const struct iio_chan_spec *channel_templates;
1188 	struct iio_chan_spec *channels, *chan;
1189 	struct fwnode_handle *chan_node, *child;
1190 	unsigned int max_channels;
1191 	unsigned int num_channels;
1192 	const char *external_mux;
1193 	u32 ext_mux_chan;
1194 	u32 reg;
1195 	int ret;
1196 	int i;
1197 
1198 	*conf = 0;
1199 
1200 	ret = device_property_read_string(dev, "xlnx,external-mux", &external_mux);
1201 	if (ret < 0 || strcasecmp(external_mux, "none") == 0)
1202 		xadc->external_mux_mode = XADC_EXTERNAL_MUX_NONE;
1203 	else if (strcasecmp(external_mux, "single") == 0)
1204 		xadc->external_mux_mode = XADC_EXTERNAL_MUX_SINGLE;
1205 	else if (strcasecmp(external_mux, "dual") == 0)
1206 		xadc->external_mux_mode = XADC_EXTERNAL_MUX_DUAL;
1207 	else
1208 		return -EINVAL;
1209 
1210 	if (xadc->external_mux_mode != XADC_EXTERNAL_MUX_NONE) {
1211 		ret = device_property_read_u32(dev, "xlnx,external-mux-channel", &ext_mux_chan);
1212 		if (ret < 0)
1213 			return ret;
1214 
1215 		if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_SINGLE) {
1216 			if (ext_mux_chan == 0)
1217 				ext_mux_chan = XADC_REG_VPVN;
1218 			else if (ext_mux_chan <= 16)
1219 				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1220 			else
1221 				return -EINVAL;
1222 		} else {
1223 			if (ext_mux_chan > 0 && ext_mux_chan <= 8)
1224 				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1225 			else
1226 				return -EINVAL;
1227 		}
1228 
1229 		*conf |= XADC_CONF0_MUX | XADC_CONF0_CHAN(ext_mux_chan);
1230 	}
1231 	if (xadc->ops->type == XADC_TYPE_S7) {
1232 		channel_templates = xadc_7s_channels;
1233 		max_channels = ARRAY_SIZE(xadc_7s_channels);
1234 	} else {
1235 		channel_templates = xadc_us_channels;
1236 		max_channels = ARRAY_SIZE(xadc_us_channels);
1237 	}
1238 	channels = devm_kmemdup(dev, channel_templates,
1239 				sizeof(channels[0]) * max_channels, GFP_KERNEL);
1240 	if (!channels)
1241 		return -ENOMEM;
1242 
1243 	num_channels = 9;
1244 	chan = &channels[9];
1245 
1246 	chan_node = device_get_named_child_node(dev, "xlnx,channels");
1247 	fwnode_for_each_child_node(chan_node, child) {
1248 		if (num_channels >= max_channels) {
1249 			fwnode_handle_put(child);
1250 			break;
1251 		}
1252 
1253 		ret = fwnode_property_read_u32(child, "reg", &reg);
1254 		if (ret || reg > 16)
1255 			continue;
1256 
1257 		if (fwnode_property_read_bool(child, "xlnx,bipolar"))
1258 			chan->scan_type.sign = 's';
1259 
1260 		if (reg == 0) {
1261 			chan->scan_index = 11;
1262 			chan->address = XADC_REG_VPVN;
1263 		} else {
1264 			chan->scan_index = 15 + reg;
1265 			chan->address = XADC_REG_VAUX(reg - 1);
1266 		}
1267 		num_channels++;
1268 		chan++;
1269 	}
1270 	fwnode_handle_put(chan_node);
1271 
1272 	/* No IRQ => no events */
1273 	if (irq <= 0) {
1274 		for (i = 0; i < num_channels; i++) {
1275 			channels[i].event_spec = NULL;
1276 			channels[i].num_event_specs = 0;
1277 		}
1278 	}
1279 
1280 	indio_dev->num_channels = num_channels;
1281 	indio_dev->channels = devm_krealloc_array(dev, channels,
1282 						  num_channels, sizeof(*channels),
1283 						  GFP_KERNEL);
1284 	/* If we can't resize the channels array, just use the original */
1285 	if (!indio_dev->channels)
1286 		indio_dev->channels = channels;
1287 
1288 	return 0;
1289 }
1290 
1291 static const char * const xadc_type_names[] = {
1292 	[XADC_TYPE_S7] = "xadc",
1293 	[XADC_TYPE_US] = "xilinx-system-monitor",
1294 };
1295 
1296 static void xadc_cancel_delayed_work(void *data)
1297 {
1298 	struct delayed_work *work = data;
1299 
1300 	cancel_delayed_work_sync(work);
1301 }
1302 
1303 static int xadc_probe(struct platform_device *pdev)
1304 {
1305 	struct device *dev = &pdev->dev;
1306 	const struct xadc_ops *ops;
1307 	struct iio_dev *indio_dev;
1308 	unsigned int bipolar_mask;
1309 	unsigned int conf0;
1310 	struct xadc *xadc;
1311 	int ret;
1312 	int irq;
1313 	int i;
1314 
1315 	ops = device_get_match_data(dev);
1316 	if (!ops)
1317 		return -EINVAL;
1318 
1319 	irq = platform_get_irq_optional(pdev, 0);
1320 	if (irq < 0 &&
1321 	    (irq != -ENXIO || !(ops->flags & XADC_FLAGS_IRQ_OPTIONAL)))
1322 		return irq;
1323 
1324 	indio_dev = devm_iio_device_alloc(dev, sizeof(*xadc));
1325 	if (!indio_dev)
1326 		return -ENOMEM;
1327 
1328 	xadc = iio_priv(indio_dev);
1329 	xadc->ops = ops;
1330 	init_completion(&xadc->completion);
1331 	mutex_init(&xadc->mutex);
1332 	spin_lock_init(&xadc->lock);
1333 	INIT_DELAYED_WORK(&xadc->zynq_unmask_work, xadc_zynq_unmask_worker);
1334 
1335 	xadc->base = devm_platform_ioremap_resource(pdev, 0);
1336 	if (IS_ERR(xadc->base))
1337 		return PTR_ERR(xadc->base);
1338 
1339 	indio_dev->name = xadc_type_names[xadc->ops->type];
1340 	indio_dev->modes = INDIO_DIRECT_MODE;
1341 	indio_dev->info = &xadc_info;
1342 
1343 	ret = xadc_parse_dt(indio_dev, &conf0, irq);
1344 	if (ret)
1345 		return ret;
1346 
1347 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1348 		ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
1349 						      &iio_pollfunc_store_time,
1350 						      &xadc_trigger_handler,
1351 						      &xadc_buffer_ops);
1352 		if (ret)
1353 			return ret;
1354 
1355 		if (irq > 0) {
1356 			xadc->convst_trigger = xadc_alloc_trigger(indio_dev, "convst");
1357 			if (IS_ERR(xadc->convst_trigger))
1358 				return PTR_ERR(xadc->convst_trigger);
1359 
1360 			xadc->samplerate_trigger = xadc_alloc_trigger(indio_dev,
1361 				"samplerate");
1362 			if (IS_ERR(xadc->samplerate_trigger))
1363 				return PTR_ERR(xadc->samplerate_trigger);
1364 		}
1365 	}
1366 
1367 	xadc->clk = devm_clk_get_enabled(dev, NULL);
1368 	if (IS_ERR(xadc->clk))
1369 		return PTR_ERR(xadc->clk);
1370 
1371 	/*
1372 	 * Make sure not to exceed the maximum samplerate since otherwise the
1373 	 * resulting interrupt storm will soft-lock the system.
1374 	 */
1375 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1376 		ret = xadc_read_samplerate(xadc);
1377 		if (ret < 0)
1378 			return ret;
1379 
1380 		if (ret > XADC_MAX_SAMPLERATE) {
1381 			ret = xadc_write_samplerate(xadc, XADC_MAX_SAMPLERATE);
1382 			if (ret < 0)
1383 				return ret;
1384 		}
1385 	}
1386 
1387 	if (irq > 0) {
1388 		ret = devm_request_irq(dev, irq, xadc->ops->interrupt_handler,
1389 				       0, dev_name(dev), indio_dev);
1390 		if (ret)
1391 			return ret;
1392 
1393 		ret = devm_add_action_or_reset(dev, xadc_cancel_delayed_work,
1394 					       &xadc->zynq_unmask_work);
1395 		if (ret)
1396 			return ret;
1397 	}
1398 
1399 	ret = xadc->ops->setup(pdev, indio_dev, irq);
1400 	if (ret)
1401 		return ret;
1402 
1403 	for (i = 0; i < 16; i++)
1404 		xadc_read_adc_reg(xadc, XADC_REG_THRESHOLD(i),
1405 			&xadc->threshold[i]);
1406 
1407 	ret = xadc_write_adc_reg(xadc, XADC_REG_CONF0, conf0);
1408 	if (ret)
1409 		return ret;
1410 
1411 	bipolar_mask = 0;
1412 	for (i = 0; i < indio_dev->num_channels; i++) {
1413 		if (indio_dev->channels[i].scan_type.sign == 's')
1414 			bipolar_mask |= BIT(indio_dev->channels[i].scan_index);
1415 	}
1416 
1417 	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(0), bipolar_mask);
1418 	if (ret)
1419 		return ret;
1420 
1421 	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(1),
1422 		bipolar_mask >> 16);
1423 	if (ret)
1424 		return ret;
1425 
1426 	/* Go to non-buffered mode */
1427 	xadc_postdisable(indio_dev);
1428 
1429 	return devm_iio_device_register(dev, indio_dev);
1430 }
1431 
1432 static struct platform_driver xadc_driver = {
1433 	.probe = xadc_probe,
1434 	.driver = {
1435 		.name = "xadc",
1436 		.of_match_table = xadc_of_match_table,
1437 	},
1438 };
1439 module_platform_driver(xadc_driver);
1440 
1441 MODULE_LICENSE("GPL v2");
1442 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1443 MODULE_DESCRIPTION("Xilinx XADC IIO driver");
1444