1 /*
2  * Xilinx XADC driver
3  *
4  * Copyright 2013-2014 Analog Devices Inc.
5  *  Author: Lars-Peter Clauen <lars@metafoo.de>
6  *
7  * Licensed under the GPL-2.
8  *
9  * Documentation for the parts can be found at:
10  *  - XADC hardmacro: Xilinx UG480
11  *  - ZYNQ XADC interface: Xilinx UG585
12  *  - AXI XADC interface: Xilinx PG019
13  */
14 
15 #include <linux/clk.h>
16 #include <linux/device.h>
17 #include <linux/err.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/platform_device.h>
24 #include <linux/slab.h>
25 #include <linux/sysfs.h>
26 
27 #include <linux/iio/buffer.h>
28 #include <linux/iio/events.h>
29 #include <linux/iio/iio.h>
30 #include <linux/iio/sysfs.h>
31 #include <linux/iio/trigger.h>
32 #include <linux/iio/trigger_consumer.h>
33 #include <linux/iio/triggered_buffer.h>
34 
35 #include "xilinx-xadc.h"
36 
37 static const unsigned int XADC_ZYNQ_UNMASK_TIMEOUT = 500;
38 
39 /* ZYNQ register definitions */
40 #define XADC_ZYNQ_REG_CFG	0x00
41 #define XADC_ZYNQ_REG_INTSTS	0x04
42 #define XADC_ZYNQ_REG_INTMSK	0x08
43 #define XADC_ZYNQ_REG_STATUS	0x0c
44 #define XADC_ZYNQ_REG_CFIFO	0x10
45 #define XADC_ZYNQ_REG_DFIFO	0x14
46 #define XADC_ZYNQ_REG_CTL		0x18
47 
48 #define XADC_ZYNQ_CFG_ENABLE		BIT(31)
49 #define XADC_ZYNQ_CFG_CFIFOTH_MASK	(0xf << 20)
50 #define XADC_ZYNQ_CFG_CFIFOTH_OFFSET	20
51 #define XADC_ZYNQ_CFG_DFIFOTH_MASK	(0xf << 16)
52 #define XADC_ZYNQ_CFG_DFIFOTH_OFFSET	16
53 #define XADC_ZYNQ_CFG_WEDGE		BIT(13)
54 #define XADC_ZYNQ_CFG_REDGE		BIT(12)
55 #define XADC_ZYNQ_CFG_TCKRATE_MASK	(0x3 << 8)
56 #define XADC_ZYNQ_CFG_TCKRATE_DIV2	(0x0 << 8)
57 #define XADC_ZYNQ_CFG_TCKRATE_DIV4	(0x1 << 8)
58 #define XADC_ZYNQ_CFG_TCKRATE_DIV8	(0x2 << 8)
59 #define XADC_ZYNQ_CFG_TCKRATE_DIV16	(0x3 << 8)
60 #define XADC_ZYNQ_CFG_IGAP_MASK		0x1f
61 #define XADC_ZYNQ_CFG_IGAP(x)		(x)
62 
63 #define XADC_ZYNQ_INT_CFIFO_LTH		BIT(9)
64 #define XADC_ZYNQ_INT_DFIFO_GTH		BIT(8)
65 #define XADC_ZYNQ_INT_ALARM_MASK	0xff
66 #define XADC_ZYNQ_INT_ALARM_OFFSET	0
67 
68 #define XADC_ZYNQ_STATUS_CFIFO_LVL_MASK	(0xf << 16)
69 #define XADC_ZYNQ_STATUS_CFIFO_LVL_OFFSET	16
70 #define XADC_ZYNQ_STATUS_DFIFO_LVL_MASK	(0xf << 12)
71 #define XADC_ZYNQ_STATUS_DFIFO_LVL_OFFSET	12
72 #define XADC_ZYNQ_STATUS_CFIFOF		BIT(11)
73 #define XADC_ZYNQ_STATUS_CFIFOE		BIT(10)
74 #define XADC_ZYNQ_STATUS_DFIFOF		BIT(9)
75 #define XADC_ZYNQ_STATUS_DFIFOE		BIT(8)
76 #define XADC_ZYNQ_STATUS_OT		BIT(7)
77 #define XADC_ZYNQ_STATUS_ALM(x)		BIT(x)
78 
79 #define XADC_ZYNQ_CTL_RESET		BIT(4)
80 
81 #define XADC_ZYNQ_CMD_NOP		0x00
82 #define XADC_ZYNQ_CMD_READ		0x01
83 #define XADC_ZYNQ_CMD_WRITE		0x02
84 
85 #define XADC_ZYNQ_CMD(cmd, addr, data) (((cmd) << 26) | ((addr) << 16) | (data))
86 
87 /* AXI register definitions */
88 #define XADC_AXI_REG_RESET		0x00
89 #define XADC_AXI_REG_STATUS		0x04
90 #define XADC_AXI_REG_ALARM_STATUS	0x08
91 #define XADC_AXI_REG_CONVST		0x0c
92 #define XADC_AXI_REG_XADC_RESET		0x10
93 #define XADC_AXI_REG_GIER		0x5c
94 #define XADC_AXI_REG_IPISR		0x60
95 #define XADC_AXI_REG_IPIER		0x68
96 #define XADC_AXI_ADC_REG_OFFSET		0x200
97 
98 #define XADC_AXI_RESET_MAGIC		0xa
99 #define XADC_AXI_GIER_ENABLE		BIT(31)
100 
101 #define XADC_AXI_INT_EOS		BIT(4)
102 #define XADC_AXI_INT_ALARM_MASK		0x3c0f
103 
104 #define XADC_FLAGS_BUFFERED BIT(0)
105 
106 static void xadc_write_reg(struct xadc *xadc, unsigned int reg,
107 	uint32_t val)
108 {
109 	writel(val, xadc->base + reg);
110 }
111 
112 static void xadc_read_reg(struct xadc *xadc, unsigned int reg,
113 	uint32_t *val)
114 {
115 	*val = readl(xadc->base + reg);
116 }
117 
118 /*
119  * The ZYNQ interface uses two asynchronous FIFOs for communication with the
120  * XADC. Reads and writes to the XADC register are performed by submitting a
121  * request to the command FIFO (CFIFO), once the request has been completed the
122  * result can be read from the data FIFO (DFIFO). The method currently used in
123  * this driver is to submit the request for a read/write operation, then go to
124  * sleep and wait for an interrupt that signals that a response is available in
125  * the data FIFO.
126  */
127 
128 static void xadc_zynq_write_fifo(struct xadc *xadc, uint32_t *cmd,
129 	unsigned int n)
130 {
131 	unsigned int i;
132 
133 	for (i = 0; i < n; i++)
134 		xadc_write_reg(xadc, XADC_ZYNQ_REG_CFIFO, cmd[i]);
135 }
136 
137 static void xadc_zynq_drain_fifo(struct xadc *xadc)
138 {
139 	uint32_t status, tmp;
140 
141 	xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status);
142 
143 	while (!(status & XADC_ZYNQ_STATUS_DFIFOE)) {
144 		xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp);
145 		xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status);
146 	}
147 }
148 
149 static void xadc_zynq_update_intmsk(struct xadc *xadc, unsigned int mask,
150 	unsigned int val)
151 {
152 	xadc->zynq_intmask &= ~mask;
153 	xadc->zynq_intmask |= val;
154 
155 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK,
156 		xadc->zynq_intmask | xadc->zynq_masked_alarm);
157 }
158 
159 static int xadc_zynq_write_adc_reg(struct xadc *xadc, unsigned int reg,
160 	uint16_t val)
161 {
162 	uint32_t cmd[1];
163 	uint32_t tmp;
164 	int ret;
165 
166 	spin_lock_irq(&xadc->lock);
167 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
168 			XADC_ZYNQ_INT_DFIFO_GTH);
169 
170 	reinit_completion(&xadc->completion);
171 
172 	cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_WRITE, reg, val);
173 	xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd));
174 	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp);
175 	tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK;
176 	tmp |= 0 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET;
177 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp);
178 
179 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0);
180 	spin_unlock_irq(&xadc->lock);
181 
182 	ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ);
183 	if (ret == 0)
184 		ret = -EIO;
185 	else
186 		ret = 0;
187 
188 	xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp);
189 
190 	return ret;
191 }
192 
193 static int xadc_zynq_read_adc_reg(struct xadc *xadc, unsigned int reg,
194 	uint16_t *val)
195 {
196 	uint32_t cmd[2];
197 	uint32_t resp, tmp;
198 	int ret;
199 
200 	cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_READ, reg, 0);
201 	cmd[1] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_NOP, 0, 0);
202 
203 	spin_lock_irq(&xadc->lock);
204 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
205 			XADC_ZYNQ_INT_DFIFO_GTH);
206 	xadc_zynq_drain_fifo(xadc);
207 	reinit_completion(&xadc->completion);
208 
209 	xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd));
210 	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp);
211 	tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK;
212 	tmp |= 1 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET;
213 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp);
214 
215 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0);
216 	spin_unlock_irq(&xadc->lock);
217 	ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ);
218 	if (ret == 0)
219 		ret = -EIO;
220 	if (ret < 0)
221 		return ret;
222 
223 	xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp);
224 	xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp);
225 
226 	*val = resp & 0xffff;
227 
228 	return 0;
229 }
230 
231 static unsigned int xadc_zynq_transform_alarm(unsigned int alarm)
232 {
233 	return ((alarm & 0x80) >> 4) |
234 		((alarm & 0x78) << 1) |
235 		(alarm & 0x07);
236 }
237 
238 /*
239  * The ZYNQ threshold interrupts are level sensitive. Since we can't make the
240  * threshold condition go way from within the interrupt handler, this means as
241  * soon as a threshold condition is present we would enter the interrupt handler
242  * again and again. To work around this we mask all active thresholds interrupts
243  * in the interrupt handler and start a timer. In this timer we poll the
244  * interrupt status and only if the interrupt is inactive we unmask it again.
245  */
246 static void xadc_zynq_unmask_worker(struct work_struct *work)
247 {
248 	struct xadc *xadc = container_of(work, struct xadc, zynq_unmask_work.work);
249 	unsigned int misc_sts, unmask;
250 
251 	xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &misc_sts);
252 
253 	misc_sts &= XADC_ZYNQ_INT_ALARM_MASK;
254 
255 	spin_lock_irq(&xadc->lock);
256 
257 	/* Clear those bits which are not active anymore */
258 	unmask = (xadc->zynq_masked_alarm ^ misc_sts) & xadc->zynq_masked_alarm;
259 	xadc->zynq_masked_alarm &= misc_sts;
260 
261 	/* Also clear those which are masked out anyway */
262 	xadc->zynq_masked_alarm &= ~xadc->zynq_intmask;
263 
264 	/* Clear the interrupts before we unmask them */
265 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, unmask);
266 
267 	xadc_zynq_update_intmsk(xadc, 0, 0);
268 
269 	spin_unlock_irq(&xadc->lock);
270 
271 	/* if still pending some alarm re-trigger the timer */
272 	if (xadc->zynq_masked_alarm) {
273 		schedule_delayed_work(&xadc->zynq_unmask_work,
274 				msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT));
275 	}
276 
277 }
278 
279 static irqreturn_t xadc_zynq_interrupt_handler(int irq, void *devid)
280 {
281 	struct iio_dev *indio_dev = devid;
282 	struct xadc *xadc = iio_priv(indio_dev);
283 	uint32_t status;
284 
285 	xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
286 
287 	status &= ~(xadc->zynq_intmask | xadc->zynq_masked_alarm);
288 
289 	if (!status)
290 		return IRQ_NONE;
291 
292 	spin_lock(&xadc->lock);
293 
294 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status);
295 
296 	if (status & XADC_ZYNQ_INT_DFIFO_GTH) {
297 		xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
298 			XADC_ZYNQ_INT_DFIFO_GTH);
299 		complete(&xadc->completion);
300 	}
301 
302 	status &= XADC_ZYNQ_INT_ALARM_MASK;
303 	if (status) {
304 		xadc->zynq_masked_alarm |= status;
305 		/*
306 		 * mask the current event interrupt,
307 		 * unmask it when the interrupt is no more active.
308 		 */
309 		xadc_zynq_update_intmsk(xadc, 0, 0);
310 
311 		xadc_handle_events(indio_dev,
312 				xadc_zynq_transform_alarm(status));
313 
314 		/* unmask the required interrupts in timer. */
315 		schedule_delayed_work(&xadc->zynq_unmask_work,
316 				msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT));
317 	}
318 	spin_unlock(&xadc->lock);
319 
320 	return IRQ_HANDLED;
321 }
322 
323 #define XADC_ZYNQ_TCK_RATE_MAX 50000000
324 #define XADC_ZYNQ_IGAP_DEFAULT 20
325 #define XADC_ZYNQ_PCAP_RATE_MAX 200000000
326 
327 static int xadc_zynq_setup(struct platform_device *pdev,
328 	struct iio_dev *indio_dev, int irq)
329 {
330 	struct xadc *xadc = iio_priv(indio_dev);
331 	unsigned long pcap_rate;
332 	unsigned int tck_div;
333 	unsigned int div;
334 	unsigned int igap;
335 	unsigned int tck_rate;
336 	int ret;
337 
338 	/* TODO: Figure out how to make igap and tck_rate configurable */
339 	igap = XADC_ZYNQ_IGAP_DEFAULT;
340 	tck_rate = XADC_ZYNQ_TCK_RATE_MAX;
341 
342 	xadc->zynq_intmask = ~0;
343 
344 	pcap_rate = clk_get_rate(xadc->clk);
345 	if (!pcap_rate)
346 		return -EINVAL;
347 
348 	if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) {
349 		ret = clk_set_rate(xadc->clk,
350 				   (unsigned long)XADC_ZYNQ_PCAP_RATE_MAX);
351 		if (ret)
352 			return ret;
353 	}
354 
355 	if (tck_rate > pcap_rate / 2) {
356 		div = 2;
357 	} else {
358 		div = pcap_rate / tck_rate;
359 		if (pcap_rate / div > XADC_ZYNQ_TCK_RATE_MAX)
360 			div++;
361 	}
362 
363 	if (div <= 3)
364 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV2;
365 	else if (div <= 7)
366 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV4;
367 	else if (div <= 15)
368 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV8;
369 	else
370 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV16;
371 
372 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, XADC_ZYNQ_CTL_RESET);
373 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, 0);
374 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, ~0);
375 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK, xadc->zynq_intmask);
376 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, XADC_ZYNQ_CFG_ENABLE |
377 			XADC_ZYNQ_CFG_REDGE | XADC_ZYNQ_CFG_WEDGE |
378 			tck_div | XADC_ZYNQ_CFG_IGAP(igap));
379 
380 	if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) {
381 		ret = clk_set_rate(xadc->clk, pcap_rate);
382 		if (ret)
383 			return ret;
384 	}
385 
386 	return 0;
387 }
388 
389 static unsigned long xadc_zynq_get_dclk_rate(struct xadc *xadc)
390 {
391 	unsigned int div;
392 	uint32_t val;
393 
394 	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &val);
395 
396 	switch (val & XADC_ZYNQ_CFG_TCKRATE_MASK) {
397 	case XADC_ZYNQ_CFG_TCKRATE_DIV4:
398 		div = 4;
399 		break;
400 	case XADC_ZYNQ_CFG_TCKRATE_DIV8:
401 		div = 8;
402 		break;
403 	case XADC_ZYNQ_CFG_TCKRATE_DIV16:
404 		div = 16;
405 		break;
406 	default:
407 		div = 2;
408 		break;
409 	}
410 
411 	return clk_get_rate(xadc->clk) / div;
412 }
413 
414 static void xadc_zynq_update_alarm(struct xadc *xadc, unsigned int alarm)
415 {
416 	unsigned long flags;
417 	uint32_t status;
418 
419 	/* Move OT to bit 7 */
420 	alarm = ((alarm & 0x08) << 4) | ((alarm & 0xf0) >> 1) | (alarm & 0x07);
421 
422 	spin_lock_irqsave(&xadc->lock, flags);
423 
424 	/* Clear previous interrupts if any. */
425 	xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
426 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status & alarm);
427 
428 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_ALARM_MASK,
429 		~alarm & XADC_ZYNQ_INT_ALARM_MASK);
430 
431 	spin_unlock_irqrestore(&xadc->lock, flags);
432 }
433 
434 static const struct xadc_ops xadc_zynq_ops = {
435 	.read = xadc_zynq_read_adc_reg,
436 	.write = xadc_zynq_write_adc_reg,
437 	.setup = xadc_zynq_setup,
438 	.get_dclk_rate = xadc_zynq_get_dclk_rate,
439 	.interrupt_handler = xadc_zynq_interrupt_handler,
440 	.update_alarm = xadc_zynq_update_alarm,
441 };
442 
443 static int xadc_axi_read_adc_reg(struct xadc *xadc, unsigned int reg,
444 	uint16_t *val)
445 {
446 	uint32_t val32;
447 
448 	xadc_read_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, &val32);
449 	*val = val32 & 0xffff;
450 
451 	return 0;
452 }
453 
454 static int xadc_axi_write_adc_reg(struct xadc *xadc, unsigned int reg,
455 	uint16_t val)
456 {
457 	xadc_write_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, val);
458 
459 	return 0;
460 }
461 
462 static int xadc_axi_setup(struct platform_device *pdev,
463 	struct iio_dev *indio_dev, int irq)
464 {
465 	struct xadc *xadc = iio_priv(indio_dev);
466 
467 	xadc_write_reg(xadc, XADC_AXI_REG_RESET, XADC_AXI_RESET_MAGIC);
468 	xadc_write_reg(xadc, XADC_AXI_REG_GIER, XADC_AXI_GIER_ENABLE);
469 
470 	return 0;
471 }
472 
473 static irqreturn_t xadc_axi_interrupt_handler(int irq, void *devid)
474 {
475 	struct iio_dev *indio_dev = devid;
476 	struct xadc *xadc = iio_priv(indio_dev);
477 	uint32_t status, mask;
478 	unsigned int events;
479 
480 	xadc_read_reg(xadc, XADC_AXI_REG_IPISR, &status);
481 	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &mask);
482 	status &= mask;
483 
484 	if (!status)
485 		return IRQ_NONE;
486 
487 	if ((status & XADC_AXI_INT_EOS) && xadc->trigger)
488 		iio_trigger_poll(xadc->trigger);
489 
490 	if (status & XADC_AXI_INT_ALARM_MASK) {
491 		/*
492 		 * The order of the bits in the AXI-XADC status register does
493 		 * not match the order of the bits in the XADC alarm enable
494 		 * register. xadc_handle_events() expects the events to be in
495 		 * the same order as the XADC alarm enable register.
496 		 */
497 		events = (status & 0x000e) >> 1;
498 		events |= (status & 0x0001) << 3;
499 		events |= (status & 0x3c00) >> 6;
500 		xadc_handle_events(indio_dev, events);
501 	}
502 
503 	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, status);
504 
505 	return IRQ_HANDLED;
506 }
507 
508 static void xadc_axi_update_alarm(struct xadc *xadc, unsigned int alarm)
509 {
510 	uint32_t val;
511 	unsigned long flags;
512 
513 	/*
514 	 * The order of the bits in the AXI-XADC status register does not match
515 	 * the order of the bits in the XADC alarm enable register. We get
516 	 * passed the alarm mask in the same order as in the XADC alarm enable
517 	 * register.
518 	 */
519 	alarm = ((alarm & 0x07) << 1) | ((alarm & 0x08) >> 3) |
520 			((alarm & 0xf0) << 6);
521 
522 	spin_lock_irqsave(&xadc->lock, flags);
523 	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
524 	val &= ~XADC_AXI_INT_ALARM_MASK;
525 	val |= alarm;
526 	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
527 	spin_unlock_irqrestore(&xadc->lock, flags);
528 }
529 
530 static unsigned long xadc_axi_get_dclk(struct xadc *xadc)
531 {
532 	return clk_get_rate(xadc->clk);
533 }
534 
535 static const struct xadc_ops xadc_axi_ops = {
536 	.read = xadc_axi_read_adc_reg,
537 	.write = xadc_axi_write_adc_reg,
538 	.setup = xadc_axi_setup,
539 	.get_dclk_rate = xadc_axi_get_dclk,
540 	.update_alarm = xadc_axi_update_alarm,
541 	.interrupt_handler = xadc_axi_interrupt_handler,
542 	.flags = XADC_FLAGS_BUFFERED,
543 };
544 
545 static int _xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
546 	uint16_t mask, uint16_t val)
547 {
548 	uint16_t tmp;
549 	int ret;
550 
551 	ret = _xadc_read_adc_reg(xadc, reg, &tmp);
552 	if (ret)
553 		return ret;
554 
555 	return _xadc_write_adc_reg(xadc, reg, (tmp & ~mask) | val);
556 }
557 
558 static int xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
559 	uint16_t mask, uint16_t val)
560 {
561 	int ret;
562 
563 	mutex_lock(&xadc->mutex);
564 	ret = _xadc_update_adc_reg(xadc, reg, mask, val);
565 	mutex_unlock(&xadc->mutex);
566 
567 	return ret;
568 }
569 
570 static unsigned long xadc_get_dclk_rate(struct xadc *xadc)
571 {
572 	return xadc->ops->get_dclk_rate(xadc);
573 }
574 
575 static int xadc_update_scan_mode(struct iio_dev *indio_dev,
576 	const unsigned long *mask)
577 {
578 	struct xadc *xadc = iio_priv(indio_dev);
579 	unsigned int n;
580 
581 	n = bitmap_weight(mask, indio_dev->masklength);
582 
583 	kfree(xadc->data);
584 	xadc->data = kcalloc(n, sizeof(*xadc->data), GFP_KERNEL);
585 	if (!xadc->data)
586 		return -ENOMEM;
587 
588 	return 0;
589 }
590 
591 static unsigned int xadc_scan_index_to_channel(unsigned int scan_index)
592 {
593 	switch (scan_index) {
594 	case 5:
595 		return XADC_REG_VCCPINT;
596 	case 6:
597 		return XADC_REG_VCCPAUX;
598 	case 7:
599 		return XADC_REG_VCCO_DDR;
600 	case 8:
601 		return XADC_REG_TEMP;
602 	case 9:
603 		return XADC_REG_VCCINT;
604 	case 10:
605 		return XADC_REG_VCCAUX;
606 	case 11:
607 		return XADC_REG_VPVN;
608 	case 12:
609 		return XADC_REG_VREFP;
610 	case 13:
611 		return XADC_REG_VREFN;
612 	case 14:
613 		return XADC_REG_VCCBRAM;
614 	default:
615 		return XADC_REG_VAUX(scan_index - 16);
616 	}
617 }
618 
619 static irqreturn_t xadc_trigger_handler(int irq, void *p)
620 {
621 	struct iio_poll_func *pf = p;
622 	struct iio_dev *indio_dev = pf->indio_dev;
623 	struct xadc *xadc = iio_priv(indio_dev);
624 	unsigned int chan;
625 	int i, j;
626 
627 	if (!xadc->data)
628 		goto out;
629 
630 	j = 0;
631 	for_each_set_bit(i, indio_dev->active_scan_mask,
632 		indio_dev->masklength) {
633 		chan = xadc_scan_index_to_channel(i);
634 		xadc_read_adc_reg(xadc, chan, &xadc->data[j]);
635 		j++;
636 	}
637 
638 	iio_push_to_buffers(indio_dev, xadc->data);
639 
640 out:
641 	iio_trigger_notify_done(indio_dev->trig);
642 
643 	return IRQ_HANDLED;
644 }
645 
646 static int xadc_trigger_set_state(struct iio_trigger *trigger, bool state)
647 {
648 	struct xadc *xadc = iio_trigger_get_drvdata(trigger);
649 	unsigned long flags;
650 	unsigned int convst;
651 	unsigned int val;
652 	int ret = 0;
653 
654 	mutex_lock(&xadc->mutex);
655 
656 	if (state) {
657 		/* Only one of the two triggers can be active at the a time. */
658 		if (xadc->trigger != NULL) {
659 			ret = -EBUSY;
660 			goto err_out;
661 		} else {
662 			xadc->trigger = trigger;
663 			if (trigger == xadc->convst_trigger)
664 				convst = XADC_CONF0_EC;
665 			else
666 				convst = 0;
667 		}
668 		ret = _xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF0_EC,
669 					convst);
670 		if (ret)
671 			goto err_out;
672 	} else {
673 		xadc->trigger = NULL;
674 	}
675 
676 	spin_lock_irqsave(&xadc->lock, flags);
677 	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
678 	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, val & XADC_AXI_INT_EOS);
679 	if (state)
680 		val |= XADC_AXI_INT_EOS;
681 	else
682 		val &= ~XADC_AXI_INT_EOS;
683 	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
684 	spin_unlock_irqrestore(&xadc->lock, flags);
685 
686 err_out:
687 	mutex_unlock(&xadc->mutex);
688 
689 	return ret;
690 }
691 
692 static const struct iio_trigger_ops xadc_trigger_ops = {
693 	.set_trigger_state = &xadc_trigger_set_state,
694 };
695 
696 static struct iio_trigger *xadc_alloc_trigger(struct iio_dev *indio_dev,
697 	const char *name)
698 {
699 	struct iio_trigger *trig;
700 	int ret;
701 
702 	trig = iio_trigger_alloc("%s%d-%s", indio_dev->name,
703 				indio_dev->id, name);
704 	if (trig == NULL)
705 		return ERR_PTR(-ENOMEM);
706 
707 	trig->dev.parent = indio_dev->dev.parent;
708 	trig->ops = &xadc_trigger_ops;
709 	iio_trigger_set_drvdata(trig, iio_priv(indio_dev));
710 
711 	ret = iio_trigger_register(trig);
712 	if (ret)
713 		goto error_free_trig;
714 
715 	return trig;
716 
717 error_free_trig:
718 	iio_trigger_free(trig);
719 	return ERR_PTR(ret);
720 }
721 
722 static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode)
723 {
724 	uint16_t val;
725 
726 	switch (seq_mode) {
727 	case XADC_CONF1_SEQ_SIMULTANEOUS:
728 	case XADC_CONF1_SEQ_INDEPENDENT:
729 		val = XADC_CONF2_PD_ADC_B;
730 		break;
731 	default:
732 		val = 0;
733 		break;
734 	}
735 
736 	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_PD_MASK,
737 		val);
738 }
739 
740 static int xadc_get_seq_mode(struct xadc *xadc, unsigned long scan_mode)
741 {
742 	unsigned int aux_scan_mode = scan_mode >> 16;
743 
744 	if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_DUAL)
745 		return XADC_CONF1_SEQ_SIMULTANEOUS;
746 
747 	if ((aux_scan_mode & 0xff00) == 0 ||
748 		(aux_scan_mode & 0x00ff) == 0)
749 		return XADC_CONF1_SEQ_CONTINUOUS;
750 
751 	return XADC_CONF1_SEQ_SIMULTANEOUS;
752 }
753 
754 static int xadc_postdisable(struct iio_dev *indio_dev)
755 {
756 	struct xadc *xadc = iio_priv(indio_dev);
757 	unsigned long scan_mask;
758 	int ret;
759 	int i;
760 
761 	scan_mask = 1; /* Run calibration as part of the sequence */
762 	for (i = 0; i < indio_dev->num_channels; i++)
763 		scan_mask |= BIT(indio_dev->channels[i].scan_index);
764 
765 	/* Enable all channels and calibration */
766 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
767 	if (ret)
768 		return ret;
769 
770 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
771 	if (ret)
772 		return ret;
773 
774 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
775 		XADC_CONF1_SEQ_CONTINUOUS);
776 	if (ret)
777 		return ret;
778 
779 	return xadc_power_adc_b(xadc, XADC_CONF1_SEQ_CONTINUOUS);
780 }
781 
782 static int xadc_preenable(struct iio_dev *indio_dev)
783 {
784 	struct xadc *xadc = iio_priv(indio_dev);
785 	unsigned long scan_mask;
786 	int seq_mode;
787 	int ret;
788 
789 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
790 		XADC_CONF1_SEQ_DEFAULT);
791 	if (ret)
792 		goto err;
793 
794 	scan_mask = *indio_dev->active_scan_mask;
795 	seq_mode = xadc_get_seq_mode(xadc, scan_mask);
796 
797 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
798 	if (ret)
799 		goto err;
800 
801 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
802 	if (ret)
803 		goto err;
804 
805 	ret = xadc_power_adc_b(xadc, seq_mode);
806 	if (ret)
807 		goto err;
808 
809 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
810 		seq_mode);
811 	if (ret)
812 		goto err;
813 
814 	return 0;
815 err:
816 	xadc_postdisable(indio_dev);
817 	return ret;
818 }
819 
820 static const struct iio_buffer_setup_ops xadc_buffer_ops = {
821 	.preenable = &xadc_preenable,
822 	.postenable = &iio_triggered_buffer_postenable,
823 	.predisable = &iio_triggered_buffer_predisable,
824 	.postdisable = &xadc_postdisable,
825 };
826 
827 static int xadc_read_raw(struct iio_dev *indio_dev,
828 	struct iio_chan_spec const *chan, int *val, int *val2, long info)
829 {
830 	struct xadc *xadc = iio_priv(indio_dev);
831 	unsigned int div;
832 	uint16_t val16;
833 	int ret;
834 
835 	switch (info) {
836 	case IIO_CHAN_INFO_RAW:
837 		if (iio_buffer_enabled(indio_dev))
838 			return -EBUSY;
839 		ret = xadc_read_adc_reg(xadc, chan->address, &val16);
840 		if (ret < 0)
841 			return ret;
842 
843 		val16 >>= 4;
844 		if (chan->scan_type.sign == 'u')
845 			*val = val16;
846 		else
847 			*val = sign_extend32(val16, 11);
848 
849 		return IIO_VAL_INT;
850 	case IIO_CHAN_INFO_SCALE:
851 		switch (chan->type) {
852 		case IIO_VOLTAGE:
853 			/* V = (val * 3.0) / 4096 */
854 			switch (chan->address) {
855 			case XADC_REG_VCCINT:
856 			case XADC_REG_VCCAUX:
857 			case XADC_REG_VREFP:
858 			case XADC_REG_VREFN:
859 			case XADC_REG_VCCBRAM:
860 			case XADC_REG_VCCPINT:
861 			case XADC_REG_VCCPAUX:
862 			case XADC_REG_VCCO_DDR:
863 				*val = 3000;
864 				break;
865 			default:
866 				*val = 1000;
867 				break;
868 			}
869 			*val2 = 12;
870 			return IIO_VAL_FRACTIONAL_LOG2;
871 		case IIO_TEMP:
872 			/* Temp in C = (val * 503.975) / 4096 - 273.15 */
873 			*val = 503975;
874 			*val2 = 12;
875 			return IIO_VAL_FRACTIONAL_LOG2;
876 		default:
877 			return -EINVAL;
878 		}
879 	case IIO_CHAN_INFO_OFFSET:
880 		/* Only the temperature channel has an offset */
881 		*val = -((273150 << 12) / 503975);
882 		return IIO_VAL_INT;
883 	case IIO_CHAN_INFO_SAMP_FREQ:
884 		ret = xadc_read_adc_reg(xadc, XADC_REG_CONF2, &val16);
885 		if (ret)
886 			return ret;
887 
888 		div = (val16 & XADC_CONF2_DIV_MASK) >> XADC_CONF2_DIV_OFFSET;
889 		if (div < 2)
890 			div = 2;
891 
892 		*val = xadc_get_dclk_rate(xadc) / div / 26;
893 
894 		return IIO_VAL_INT;
895 	default:
896 		return -EINVAL;
897 	}
898 }
899 
900 static int xadc_write_raw(struct iio_dev *indio_dev,
901 	struct iio_chan_spec const *chan, int val, int val2, long info)
902 {
903 	struct xadc *xadc = iio_priv(indio_dev);
904 	unsigned long clk_rate = xadc_get_dclk_rate(xadc);
905 	unsigned int div;
906 
907 	if (!clk_rate)
908 		return -EINVAL;
909 
910 	if (info != IIO_CHAN_INFO_SAMP_FREQ)
911 		return -EINVAL;
912 
913 	if (val <= 0)
914 		return -EINVAL;
915 
916 	/* Max. 150 kSPS */
917 	if (val > 150000)
918 		val = 150000;
919 
920 	val *= 26;
921 
922 	/* Min 1MHz */
923 	if (val < 1000000)
924 		val = 1000000;
925 
926 	/*
927 	 * We want to round down, but only if we do not exceed the 150 kSPS
928 	 * limit.
929 	 */
930 	div = clk_rate / val;
931 	if (clk_rate / div / 26 > 150000)
932 		div++;
933 	if (div < 2)
934 		div = 2;
935 	else if (div > 0xff)
936 		div = 0xff;
937 
938 	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_DIV_MASK,
939 		div << XADC_CONF2_DIV_OFFSET);
940 }
941 
942 static const struct iio_event_spec xadc_temp_events[] = {
943 	{
944 		.type = IIO_EV_TYPE_THRESH,
945 		.dir = IIO_EV_DIR_RISING,
946 		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
947 				BIT(IIO_EV_INFO_VALUE) |
948 				BIT(IIO_EV_INFO_HYSTERESIS),
949 	},
950 };
951 
952 /* Separate values for upper and lower thresholds, but only a shared enabled */
953 static const struct iio_event_spec xadc_voltage_events[] = {
954 	{
955 		.type = IIO_EV_TYPE_THRESH,
956 		.dir = IIO_EV_DIR_RISING,
957 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
958 	}, {
959 		.type = IIO_EV_TYPE_THRESH,
960 		.dir = IIO_EV_DIR_FALLING,
961 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
962 	}, {
963 		.type = IIO_EV_TYPE_THRESH,
964 		.dir = IIO_EV_DIR_EITHER,
965 		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
966 	},
967 };
968 
969 #define XADC_CHAN_TEMP(_chan, _scan_index, _addr) { \
970 	.type = IIO_TEMP, \
971 	.indexed = 1, \
972 	.channel = (_chan), \
973 	.address = (_addr), \
974 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
975 		BIT(IIO_CHAN_INFO_SCALE) | \
976 		BIT(IIO_CHAN_INFO_OFFSET), \
977 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
978 	.event_spec = xadc_temp_events, \
979 	.num_event_specs = ARRAY_SIZE(xadc_temp_events), \
980 	.scan_index = (_scan_index), \
981 	.scan_type = { \
982 		.sign = 'u', \
983 		.realbits = 12, \
984 		.storagebits = 16, \
985 		.shift = 4, \
986 		.endianness = IIO_CPU, \
987 	}, \
988 }
989 
990 #define XADC_CHAN_VOLTAGE(_chan, _scan_index, _addr, _ext, _alarm) { \
991 	.type = IIO_VOLTAGE, \
992 	.indexed = 1, \
993 	.channel = (_chan), \
994 	.address = (_addr), \
995 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
996 		BIT(IIO_CHAN_INFO_SCALE), \
997 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
998 	.event_spec = (_alarm) ? xadc_voltage_events : NULL, \
999 	.num_event_specs = (_alarm) ? ARRAY_SIZE(xadc_voltage_events) : 0, \
1000 	.scan_index = (_scan_index), \
1001 	.scan_type = { \
1002 		.sign = ((_addr) == XADC_REG_VREFN) ? 's' : 'u', \
1003 		.realbits = 12, \
1004 		.storagebits = 16, \
1005 		.shift = 4, \
1006 		.endianness = IIO_CPU, \
1007 	}, \
1008 	.extend_name = _ext, \
1009 }
1010 
1011 static const struct iio_chan_spec xadc_channels[] = {
1012 	XADC_CHAN_TEMP(0, 8, XADC_REG_TEMP),
1013 	XADC_CHAN_VOLTAGE(0, 9, XADC_REG_VCCINT, "vccint", true),
1014 	XADC_CHAN_VOLTAGE(1, 10, XADC_REG_VCCAUX, "vccaux", true),
1015 	XADC_CHAN_VOLTAGE(2, 14, XADC_REG_VCCBRAM, "vccbram", true),
1016 	XADC_CHAN_VOLTAGE(3, 5, XADC_REG_VCCPINT, "vccpint", true),
1017 	XADC_CHAN_VOLTAGE(4, 6, XADC_REG_VCCPAUX, "vccpaux", true),
1018 	XADC_CHAN_VOLTAGE(5, 7, XADC_REG_VCCO_DDR, "vccoddr", true),
1019 	XADC_CHAN_VOLTAGE(6, 12, XADC_REG_VREFP, "vrefp", false),
1020 	XADC_CHAN_VOLTAGE(7, 13, XADC_REG_VREFN, "vrefn", false),
1021 	XADC_CHAN_VOLTAGE(8, 11, XADC_REG_VPVN, NULL, false),
1022 	XADC_CHAN_VOLTAGE(9, 16, XADC_REG_VAUX(0), NULL, false),
1023 	XADC_CHAN_VOLTAGE(10, 17, XADC_REG_VAUX(1), NULL, false),
1024 	XADC_CHAN_VOLTAGE(11, 18, XADC_REG_VAUX(2), NULL, false),
1025 	XADC_CHAN_VOLTAGE(12, 19, XADC_REG_VAUX(3), NULL, false),
1026 	XADC_CHAN_VOLTAGE(13, 20, XADC_REG_VAUX(4), NULL, false),
1027 	XADC_CHAN_VOLTAGE(14, 21, XADC_REG_VAUX(5), NULL, false),
1028 	XADC_CHAN_VOLTAGE(15, 22, XADC_REG_VAUX(6), NULL, false),
1029 	XADC_CHAN_VOLTAGE(16, 23, XADC_REG_VAUX(7), NULL, false),
1030 	XADC_CHAN_VOLTAGE(17, 24, XADC_REG_VAUX(8), NULL, false),
1031 	XADC_CHAN_VOLTAGE(18, 25, XADC_REG_VAUX(9), NULL, false),
1032 	XADC_CHAN_VOLTAGE(19, 26, XADC_REG_VAUX(10), NULL, false),
1033 	XADC_CHAN_VOLTAGE(20, 27, XADC_REG_VAUX(11), NULL, false),
1034 	XADC_CHAN_VOLTAGE(21, 28, XADC_REG_VAUX(12), NULL, false),
1035 	XADC_CHAN_VOLTAGE(22, 29, XADC_REG_VAUX(13), NULL, false),
1036 	XADC_CHAN_VOLTAGE(23, 30, XADC_REG_VAUX(14), NULL, false),
1037 	XADC_CHAN_VOLTAGE(24, 31, XADC_REG_VAUX(15), NULL, false),
1038 };
1039 
1040 static const struct iio_info xadc_info = {
1041 	.read_raw = &xadc_read_raw,
1042 	.write_raw = &xadc_write_raw,
1043 	.read_event_config = &xadc_read_event_config,
1044 	.write_event_config = &xadc_write_event_config,
1045 	.read_event_value = &xadc_read_event_value,
1046 	.write_event_value = &xadc_write_event_value,
1047 	.update_scan_mode = &xadc_update_scan_mode,
1048 };
1049 
1050 static const struct of_device_id xadc_of_match_table[] = {
1051 	{ .compatible = "xlnx,zynq-xadc-1.00.a", (void *)&xadc_zynq_ops },
1052 	{ .compatible = "xlnx,axi-xadc-1.00.a", (void *)&xadc_axi_ops },
1053 	{ },
1054 };
1055 MODULE_DEVICE_TABLE(of, xadc_of_match_table);
1056 
1057 static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
1058 	unsigned int *conf)
1059 {
1060 	struct xadc *xadc = iio_priv(indio_dev);
1061 	struct iio_chan_spec *channels, *chan;
1062 	struct device_node *chan_node, *child;
1063 	unsigned int num_channels;
1064 	const char *external_mux;
1065 	u32 ext_mux_chan;
1066 	u32 reg;
1067 	int ret;
1068 
1069 	*conf = 0;
1070 
1071 	ret = of_property_read_string(np, "xlnx,external-mux", &external_mux);
1072 	if (ret < 0 || strcasecmp(external_mux, "none") == 0)
1073 		xadc->external_mux_mode = XADC_EXTERNAL_MUX_NONE;
1074 	else if (strcasecmp(external_mux, "single") == 0)
1075 		xadc->external_mux_mode = XADC_EXTERNAL_MUX_SINGLE;
1076 	else if (strcasecmp(external_mux, "dual") == 0)
1077 		xadc->external_mux_mode = XADC_EXTERNAL_MUX_DUAL;
1078 	else
1079 		return -EINVAL;
1080 
1081 	if (xadc->external_mux_mode != XADC_EXTERNAL_MUX_NONE) {
1082 		ret = of_property_read_u32(np, "xlnx,external-mux-channel",
1083 					&ext_mux_chan);
1084 		if (ret < 0)
1085 			return ret;
1086 
1087 		if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_SINGLE) {
1088 			if (ext_mux_chan == 0)
1089 				ext_mux_chan = XADC_REG_VPVN;
1090 			else if (ext_mux_chan <= 16)
1091 				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1092 			else
1093 				return -EINVAL;
1094 		} else {
1095 			if (ext_mux_chan > 0 && ext_mux_chan <= 8)
1096 				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1097 			else
1098 				return -EINVAL;
1099 		}
1100 
1101 		*conf |= XADC_CONF0_MUX | XADC_CONF0_CHAN(ext_mux_chan);
1102 	}
1103 
1104 	channels = kmemdup(xadc_channels, sizeof(xadc_channels), GFP_KERNEL);
1105 	if (!channels)
1106 		return -ENOMEM;
1107 
1108 	num_channels = 9;
1109 	chan = &channels[9];
1110 
1111 	chan_node = of_get_child_by_name(np, "xlnx,channels");
1112 	if (chan_node) {
1113 		for_each_child_of_node(chan_node, child) {
1114 			if (num_channels >= ARRAY_SIZE(xadc_channels)) {
1115 				of_node_put(child);
1116 				break;
1117 			}
1118 
1119 			ret = of_property_read_u32(child, "reg", &reg);
1120 			if (ret || reg > 16)
1121 				continue;
1122 
1123 			if (of_property_read_bool(child, "xlnx,bipolar"))
1124 				chan->scan_type.sign = 's';
1125 
1126 			if (reg == 0) {
1127 				chan->scan_index = 11;
1128 				chan->address = XADC_REG_VPVN;
1129 			} else {
1130 				chan->scan_index = 15 + reg;
1131 				chan->address = XADC_REG_VAUX(reg - 1);
1132 			}
1133 			num_channels++;
1134 			chan++;
1135 		}
1136 	}
1137 	of_node_put(chan_node);
1138 
1139 	indio_dev->num_channels = num_channels;
1140 	indio_dev->channels = krealloc(channels, sizeof(*channels) *
1141 					num_channels, GFP_KERNEL);
1142 	/* If we can't resize the channels array, just use the original */
1143 	if (!indio_dev->channels)
1144 		indio_dev->channels = channels;
1145 
1146 	return 0;
1147 }
1148 
1149 static int xadc_probe(struct platform_device *pdev)
1150 {
1151 	const struct of_device_id *id;
1152 	struct iio_dev *indio_dev;
1153 	unsigned int bipolar_mask;
1154 	struct resource *mem;
1155 	unsigned int conf0;
1156 	struct xadc *xadc;
1157 	int ret;
1158 	int irq;
1159 	int i;
1160 
1161 	if (!pdev->dev.of_node)
1162 		return -ENODEV;
1163 
1164 	id = of_match_node(xadc_of_match_table, pdev->dev.of_node);
1165 	if (!id)
1166 		return -EINVAL;
1167 
1168 	irq = platform_get_irq(pdev, 0);
1169 	if (irq <= 0)
1170 		return -ENXIO;
1171 
1172 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*xadc));
1173 	if (!indio_dev)
1174 		return -ENOMEM;
1175 
1176 	xadc = iio_priv(indio_dev);
1177 	xadc->ops = id->data;
1178 	xadc->irq = irq;
1179 	init_completion(&xadc->completion);
1180 	mutex_init(&xadc->mutex);
1181 	spin_lock_init(&xadc->lock);
1182 	INIT_DELAYED_WORK(&xadc->zynq_unmask_work, xadc_zynq_unmask_worker);
1183 
1184 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1185 	xadc->base = devm_ioremap_resource(&pdev->dev, mem);
1186 	if (IS_ERR(xadc->base))
1187 		return PTR_ERR(xadc->base);
1188 
1189 	indio_dev->dev.parent = &pdev->dev;
1190 	indio_dev->dev.of_node = pdev->dev.of_node;
1191 	indio_dev->name = "xadc";
1192 	indio_dev->modes = INDIO_DIRECT_MODE;
1193 	indio_dev->info = &xadc_info;
1194 
1195 	ret = xadc_parse_dt(indio_dev, pdev->dev.of_node, &conf0);
1196 	if (ret)
1197 		goto err_device_free;
1198 
1199 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1200 		ret = iio_triggered_buffer_setup(indio_dev,
1201 			&iio_pollfunc_store_time, &xadc_trigger_handler,
1202 			&xadc_buffer_ops);
1203 		if (ret)
1204 			goto err_device_free;
1205 
1206 		xadc->convst_trigger = xadc_alloc_trigger(indio_dev, "convst");
1207 		if (IS_ERR(xadc->convst_trigger)) {
1208 			ret = PTR_ERR(xadc->convst_trigger);
1209 			goto err_triggered_buffer_cleanup;
1210 		}
1211 		xadc->samplerate_trigger = xadc_alloc_trigger(indio_dev,
1212 			"samplerate");
1213 		if (IS_ERR(xadc->samplerate_trigger)) {
1214 			ret = PTR_ERR(xadc->samplerate_trigger);
1215 			goto err_free_convst_trigger;
1216 		}
1217 	}
1218 
1219 	xadc->clk = devm_clk_get(&pdev->dev, NULL);
1220 	if (IS_ERR(xadc->clk)) {
1221 		ret = PTR_ERR(xadc->clk);
1222 		goto err_free_samplerate_trigger;
1223 	}
1224 
1225 	ret = clk_prepare_enable(xadc->clk);
1226 	if (ret)
1227 		goto err_free_samplerate_trigger;
1228 
1229 	ret = request_irq(xadc->irq, xadc->ops->interrupt_handler, 0,
1230 			dev_name(&pdev->dev), indio_dev);
1231 	if (ret)
1232 		goto err_clk_disable_unprepare;
1233 
1234 	ret = xadc->ops->setup(pdev, indio_dev, xadc->irq);
1235 	if (ret)
1236 		goto err_free_irq;
1237 
1238 	for (i = 0; i < 16; i++)
1239 		xadc_read_adc_reg(xadc, XADC_REG_THRESHOLD(i),
1240 			&xadc->threshold[i]);
1241 
1242 	ret = xadc_write_adc_reg(xadc, XADC_REG_CONF0, conf0);
1243 	if (ret)
1244 		goto err_free_irq;
1245 
1246 	bipolar_mask = 0;
1247 	for (i = 0; i < indio_dev->num_channels; i++) {
1248 		if (indio_dev->channels[i].scan_type.sign == 's')
1249 			bipolar_mask |= BIT(indio_dev->channels[i].scan_index);
1250 	}
1251 
1252 	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(0), bipolar_mask);
1253 	if (ret)
1254 		goto err_free_irq;
1255 	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(1),
1256 		bipolar_mask >> 16);
1257 	if (ret)
1258 		goto err_free_irq;
1259 
1260 	/* Disable all alarms */
1261 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_ALARM_MASK,
1262 				  XADC_CONF1_ALARM_MASK);
1263 	if (ret)
1264 		goto err_free_irq;
1265 
1266 	/* Set thresholds to min/max */
1267 	for (i = 0; i < 16; i++) {
1268 		/*
1269 		 * Set max voltage threshold and both temperature thresholds to
1270 		 * 0xffff, min voltage threshold to 0.
1271 		 */
1272 		if (i % 8 < 4 || i == 7)
1273 			xadc->threshold[i] = 0xffff;
1274 		else
1275 			xadc->threshold[i] = 0;
1276 		xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(i),
1277 			xadc->threshold[i]);
1278 	}
1279 
1280 	/* Go to non-buffered mode */
1281 	xadc_postdisable(indio_dev);
1282 
1283 	ret = iio_device_register(indio_dev);
1284 	if (ret)
1285 		goto err_free_irq;
1286 
1287 	platform_set_drvdata(pdev, indio_dev);
1288 
1289 	return 0;
1290 
1291 err_free_irq:
1292 	free_irq(xadc->irq, indio_dev);
1293 err_clk_disable_unprepare:
1294 	clk_disable_unprepare(xadc->clk);
1295 err_free_samplerate_trigger:
1296 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1297 		iio_trigger_free(xadc->samplerate_trigger);
1298 err_free_convst_trigger:
1299 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1300 		iio_trigger_free(xadc->convst_trigger);
1301 err_triggered_buffer_cleanup:
1302 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1303 		iio_triggered_buffer_cleanup(indio_dev);
1304 err_device_free:
1305 	kfree(indio_dev->channels);
1306 
1307 	return ret;
1308 }
1309 
1310 static int xadc_remove(struct platform_device *pdev)
1311 {
1312 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1313 	struct xadc *xadc = iio_priv(indio_dev);
1314 
1315 	iio_device_unregister(indio_dev);
1316 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1317 		iio_trigger_free(xadc->samplerate_trigger);
1318 		iio_trigger_free(xadc->convst_trigger);
1319 		iio_triggered_buffer_cleanup(indio_dev);
1320 	}
1321 	free_irq(xadc->irq, indio_dev);
1322 	clk_disable_unprepare(xadc->clk);
1323 	cancel_delayed_work(&xadc->zynq_unmask_work);
1324 	kfree(xadc->data);
1325 	kfree(indio_dev->channels);
1326 
1327 	return 0;
1328 }
1329 
1330 static struct platform_driver xadc_driver = {
1331 	.probe = xadc_probe,
1332 	.remove = xadc_remove,
1333 	.driver = {
1334 		.name = "xadc",
1335 		.of_match_table = xadc_of_match_table,
1336 	},
1337 };
1338 module_platform_driver(xadc_driver);
1339 
1340 MODULE_LICENSE("GPL v2");
1341 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1342 MODULE_DESCRIPTION("Xilinx XADC IIO driver");
1343