xref: /linux/drivers/iio/adc/xilinx-xadc-core.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 
326 static int xadc_zynq_setup(struct platform_device *pdev,
327 	struct iio_dev *indio_dev, int irq)
328 {
329 	struct xadc *xadc = iio_priv(indio_dev);
330 	unsigned long pcap_rate;
331 	unsigned int tck_div;
332 	unsigned int div;
333 	unsigned int igap;
334 	unsigned int tck_rate;
335 
336 	/* TODO: Figure out how to make igap and tck_rate configurable */
337 	igap = XADC_ZYNQ_IGAP_DEFAULT;
338 	tck_rate = XADC_ZYNQ_TCK_RATE_MAX;
339 
340 	xadc->zynq_intmask = ~0;
341 
342 	pcap_rate = clk_get_rate(xadc->clk);
343 
344 	if (tck_rate > XADC_ZYNQ_TCK_RATE_MAX)
345 		tck_rate = XADC_ZYNQ_TCK_RATE_MAX;
346 	if (tck_rate > pcap_rate / 2) {
347 		div = 2;
348 	} else {
349 		div = pcap_rate / tck_rate;
350 		if (pcap_rate / div > XADC_ZYNQ_TCK_RATE_MAX)
351 			div++;
352 	}
353 
354 	if (div <= 3)
355 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV2;
356 	else if (div <= 7)
357 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV4;
358 	else if (div <= 15)
359 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV8;
360 	else
361 		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV16;
362 
363 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, XADC_ZYNQ_CTL_RESET);
364 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, 0);
365 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, ~0);
366 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK, xadc->zynq_intmask);
367 	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, XADC_ZYNQ_CFG_ENABLE |
368 			XADC_ZYNQ_CFG_REDGE | XADC_ZYNQ_CFG_WEDGE |
369 			tck_div | XADC_ZYNQ_CFG_IGAP(igap));
370 
371 	return 0;
372 }
373 
374 static unsigned long xadc_zynq_get_dclk_rate(struct xadc *xadc)
375 {
376 	unsigned int div;
377 	uint32_t val;
378 
379 	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &val);
380 
381 	switch (val & XADC_ZYNQ_CFG_TCKRATE_MASK) {
382 	case XADC_ZYNQ_CFG_TCKRATE_DIV4:
383 		div = 4;
384 		break;
385 	case XADC_ZYNQ_CFG_TCKRATE_DIV8:
386 		div = 8;
387 		break;
388 	case XADC_ZYNQ_CFG_TCKRATE_DIV16:
389 		div = 16;
390 		break;
391 	default:
392 		div = 2;
393 		break;
394 	}
395 
396 	return clk_get_rate(xadc->clk) / div;
397 }
398 
399 static void xadc_zynq_update_alarm(struct xadc *xadc, unsigned int alarm)
400 {
401 	unsigned long flags;
402 	uint32_t status;
403 
404 	/* Move OT to bit 7 */
405 	alarm = ((alarm & 0x08) << 4) | ((alarm & 0xf0) >> 1) | (alarm & 0x07);
406 
407 	spin_lock_irqsave(&xadc->lock, flags);
408 
409 	/* Clear previous interrupts if any. */
410 	xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
411 	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status & alarm);
412 
413 	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_ALARM_MASK,
414 		~alarm & XADC_ZYNQ_INT_ALARM_MASK);
415 
416 	spin_unlock_irqrestore(&xadc->lock, flags);
417 }
418 
419 static const struct xadc_ops xadc_zynq_ops = {
420 	.read = xadc_zynq_read_adc_reg,
421 	.write = xadc_zynq_write_adc_reg,
422 	.setup = xadc_zynq_setup,
423 	.get_dclk_rate = xadc_zynq_get_dclk_rate,
424 	.interrupt_handler = xadc_zynq_interrupt_handler,
425 	.update_alarm = xadc_zynq_update_alarm,
426 };
427 
428 static int xadc_axi_read_adc_reg(struct xadc *xadc, unsigned int reg,
429 	uint16_t *val)
430 {
431 	uint32_t val32;
432 
433 	xadc_read_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, &val32);
434 	*val = val32 & 0xffff;
435 
436 	return 0;
437 }
438 
439 static int xadc_axi_write_adc_reg(struct xadc *xadc, unsigned int reg,
440 	uint16_t val)
441 {
442 	xadc_write_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, val);
443 
444 	return 0;
445 }
446 
447 static int xadc_axi_setup(struct platform_device *pdev,
448 	struct iio_dev *indio_dev, int irq)
449 {
450 	struct xadc *xadc = iio_priv(indio_dev);
451 
452 	xadc_write_reg(xadc, XADC_AXI_REG_RESET, XADC_AXI_RESET_MAGIC);
453 	xadc_write_reg(xadc, XADC_AXI_REG_GIER, XADC_AXI_GIER_ENABLE);
454 
455 	return 0;
456 }
457 
458 static irqreturn_t xadc_axi_interrupt_handler(int irq, void *devid)
459 {
460 	struct iio_dev *indio_dev = devid;
461 	struct xadc *xadc = iio_priv(indio_dev);
462 	uint32_t status, mask;
463 	unsigned int events;
464 
465 	xadc_read_reg(xadc, XADC_AXI_REG_IPISR, &status);
466 	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &mask);
467 	status &= mask;
468 
469 	if (!status)
470 		return IRQ_NONE;
471 
472 	if ((status & XADC_AXI_INT_EOS) && xadc->trigger)
473 		iio_trigger_poll(xadc->trigger);
474 
475 	if (status & XADC_AXI_INT_ALARM_MASK) {
476 		/*
477 		 * The order of the bits in the AXI-XADC status register does
478 		 * not match the order of the bits in the XADC alarm enable
479 		 * register. xadc_handle_events() expects the events to be in
480 		 * the same order as the XADC alarm enable register.
481 		 */
482 		events = (status & 0x000e) >> 1;
483 		events |= (status & 0x0001) << 3;
484 		events |= (status & 0x3c00) >> 6;
485 		xadc_handle_events(indio_dev, events);
486 	}
487 
488 	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, status);
489 
490 	return IRQ_HANDLED;
491 }
492 
493 static void xadc_axi_update_alarm(struct xadc *xadc, unsigned int alarm)
494 {
495 	uint32_t val;
496 	unsigned long flags;
497 
498 	/*
499 	 * The order of the bits in the AXI-XADC status register does not match
500 	 * the order of the bits in the XADC alarm enable register. We get
501 	 * passed the alarm mask in the same order as in the XADC alarm enable
502 	 * register.
503 	 */
504 	alarm = ((alarm & 0x07) << 1) | ((alarm & 0x08) >> 3) |
505 			((alarm & 0xf0) << 6);
506 
507 	spin_lock_irqsave(&xadc->lock, flags);
508 	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
509 	val &= ~XADC_AXI_INT_ALARM_MASK;
510 	val |= alarm;
511 	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
512 	spin_unlock_irqrestore(&xadc->lock, flags);
513 }
514 
515 static unsigned long xadc_axi_get_dclk(struct xadc *xadc)
516 {
517 	return clk_get_rate(xadc->clk);
518 }
519 
520 static const struct xadc_ops xadc_axi_ops = {
521 	.read = xadc_axi_read_adc_reg,
522 	.write = xadc_axi_write_adc_reg,
523 	.setup = xadc_axi_setup,
524 	.get_dclk_rate = xadc_axi_get_dclk,
525 	.update_alarm = xadc_axi_update_alarm,
526 	.interrupt_handler = xadc_axi_interrupt_handler,
527 	.flags = XADC_FLAGS_BUFFERED,
528 };
529 
530 static int _xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
531 	uint16_t mask, uint16_t val)
532 {
533 	uint16_t tmp;
534 	int ret;
535 
536 	ret = _xadc_read_adc_reg(xadc, reg, &tmp);
537 	if (ret)
538 		return ret;
539 
540 	return _xadc_write_adc_reg(xadc, reg, (tmp & ~mask) | val);
541 }
542 
543 static int xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
544 	uint16_t mask, uint16_t val)
545 {
546 	int ret;
547 
548 	mutex_lock(&xadc->mutex);
549 	ret = _xadc_update_adc_reg(xadc, reg, mask, val);
550 	mutex_unlock(&xadc->mutex);
551 
552 	return ret;
553 }
554 
555 static unsigned long xadc_get_dclk_rate(struct xadc *xadc)
556 {
557 	return xadc->ops->get_dclk_rate(xadc);
558 }
559 
560 static int xadc_update_scan_mode(struct iio_dev *indio_dev,
561 	const unsigned long *mask)
562 {
563 	struct xadc *xadc = iio_priv(indio_dev);
564 	unsigned int n;
565 
566 	n = bitmap_weight(mask, indio_dev->masklength);
567 
568 	kfree(xadc->data);
569 	xadc->data = kcalloc(n, sizeof(*xadc->data), GFP_KERNEL);
570 	if (!xadc->data)
571 		return -ENOMEM;
572 
573 	return 0;
574 }
575 
576 static unsigned int xadc_scan_index_to_channel(unsigned int scan_index)
577 {
578 	switch (scan_index) {
579 	case 5:
580 		return XADC_REG_VCCPINT;
581 	case 6:
582 		return XADC_REG_VCCPAUX;
583 	case 7:
584 		return XADC_REG_VCCO_DDR;
585 	case 8:
586 		return XADC_REG_TEMP;
587 	case 9:
588 		return XADC_REG_VCCINT;
589 	case 10:
590 		return XADC_REG_VCCAUX;
591 	case 11:
592 		return XADC_REG_VPVN;
593 	case 12:
594 		return XADC_REG_VREFP;
595 	case 13:
596 		return XADC_REG_VREFN;
597 	case 14:
598 		return XADC_REG_VCCBRAM;
599 	default:
600 		return XADC_REG_VAUX(scan_index - 16);
601 	}
602 }
603 
604 static irqreturn_t xadc_trigger_handler(int irq, void *p)
605 {
606 	struct iio_poll_func *pf = p;
607 	struct iio_dev *indio_dev = pf->indio_dev;
608 	struct xadc *xadc = iio_priv(indio_dev);
609 	unsigned int chan;
610 	int i, j;
611 
612 	if (!xadc->data)
613 		goto out;
614 
615 	j = 0;
616 	for_each_set_bit(i, indio_dev->active_scan_mask,
617 		indio_dev->masklength) {
618 		chan = xadc_scan_index_to_channel(i);
619 		xadc_read_adc_reg(xadc, chan, &xadc->data[j]);
620 		j++;
621 	}
622 
623 	iio_push_to_buffers(indio_dev, xadc->data);
624 
625 out:
626 	iio_trigger_notify_done(indio_dev->trig);
627 
628 	return IRQ_HANDLED;
629 }
630 
631 static int xadc_trigger_set_state(struct iio_trigger *trigger, bool state)
632 {
633 	struct xadc *xadc = iio_trigger_get_drvdata(trigger);
634 	unsigned long flags;
635 	unsigned int convst;
636 	unsigned int val;
637 	int ret = 0;
638 
639 	mutex_lock(&xadc->mutex);
640 
641 	if (state) {
642 		/* Only one of the two triggers can be active at the a time. */
643 		if (xadc->trigger != NULL) {
644 			ret = -EBUSY;
645 			goto err_out;
646 		} else {
647 			xadc->trigger = trigger;
648 			if (trigger == xadc->convst_trigger)
649 				convst = XADC_CONF0_EC;
650 			else
651 				convst = 0;
652 		}
653 		ret = _xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF0_EC,
654 					convst);
655 		if (ret)
656 			goto err_out;
657 	} else {
658 		xadc->trigger = NULL;
659 	}
660 
661 	spin_lock_irqsave(&xadc->lock, flags);
662 	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
663 	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, val & XADC_AXI_INT_EOS);
664 	if (state)
665 		val |= XADC_AXI_INT_EOS;
666 	else
667 		val &= ~XADC_AXI_INT_EOS;
668 	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
669 	spin_unlock_irqrestore(&xadc->lock, flags);
670 
671 err_out:
672 	mutex_unlock(&xadc->mutex);
673 
674 	return ret;
675 }
676 
677 static const struct iio_trigger_ops xadc_trigger_ops = {
678 	.owner = THIS_MODULE,
679 	.set_trigger_state = &xadc_trigger_set_state,
680 };
681 
682 static struct iio_trigger *xadc_alloc_trigger(struct iio_dev *indio_dev,
683 	const char *name)
684 {
685 	struct iio_trigger *trig;
686 	int ret;
687 
688 	trig = iio_trigger_alloc("%s%d-%s", indio_dev->name,
689 				indio_dev->id, name);
690 	if (trig == NULL)
691 		return ERR_PTR(-ENOMEM);
692 
693 	trig->dev.parent = indio_dev->dev.parent;
694 	trig->ops = &xadc_trigger_ops;
695 	iio_trigger_set_drvdata(trig, iio_priv(indio_dev));
696 
697 	ret = iio_trigger_register(trig);
698 	if (ret)
699 		goto error_free_trig;
700 
701 	return trig;
702 
703 error_free_trig:
704 	iio_trigger_free(trig);
705 	return ERR_PTR(ret);
706 }
707 
708 static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode)
709 {
710 	uint16_t val;
711 
712 	switch (seq_mode) {
713 	case XADC_CONF1_SEQ_SIMULTANEOUS:
714 	case XADC_CONF1_SEQ_INDEPENDENT:
715 		val = XADC_CONF2_PD_ADC_B;
716 		break;
717 	default:
718 		val = 0;
719 		break;
720 	}
721 
722 	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_PD_MASK,
723 		val);
724 }
725 
726 static int xadc_get_seq_mode(struct xadc *xadc, unsigned long scan_mode)
727 {
728 	unsigned int aux_scan_mode = scan_mode >> 16;
729 
730 	if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_DUAL)
731 		return XADC_CONF1_SEQ_SIMULTANEOUS;
732 
733 	if ((aux_scan_mode & 0xff00) == 0 ||
734 		(aux_scan_mode & 0x00ff) == 0)
735 		return XADC_CONF1_SEQ_CONTINUOUS;
736 
737 	return XADC_CONF1_SEQ_SIMULTANEOUS;
738 }
739 
740 static int xadc_postdisable(struct iio_dev *indio_dev)
741 {
742 	struct xadc *xadc = iio_priv(indio_dev);
743 	unsigned long scan_mask;
744 	int ret;
745 	int i;
746 
747 	scan_mask = 1; /* Run calibration as part of the sequence */
748 	for (i = 0; i < indio_dev->num_channels; i++)
749 		scan_mask |= BIT(indio_dev->channels[i].scan_index);
750 
751 	/* Enable all channels and calibration */
752 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
753 	if (ret)
754 		return ret;
755 
756 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
757 	if (ret)
758 		return ret;
759 
760 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
761 		XADC_CONF1_SEQ_CONTINUOUS);
762 	if (ret)
763 		return ret;
764 
765 	return xadc_power_adc_b(xadc, XADC_CONF1_SEQ_CONTINUOUS);
766 }
767 
768 static int xadc_preenable(struct iio_dev *indio_dev)
769 {
770 	struct xadc *xadc = iio_priv(indio_dev);
771 	unsigned long scan_mask;
772 	int seq_mode;
773 	int ret;
774 
775 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
776 		XADC_CONF1_SEQ_DEFAULT);
777 	if (ret)
778 		goto err;
779 
780 	scan_mask = *indio_dev->active_scan_mask;
781 	seq_mode = xadc_get_seq_mode(xadc, scan_mask);
782 
783 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
784 	if (ret)
785 		goto err;
786 
787 	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
788 	if (ret)
789 		goto err;
790 
791 	ret = xadc_power_adc_b(xadc, seq_mode);
792 	if (ret)
793 		goto err;
794 
795 	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
796 		seq_mode);
797 	if (ret)
798 		goto err;
799 
800 	return 0;
801 err:
802 	xadc_postdisable(indio_dev);
803 	return ret;
804 }
805 
806 static const struct iio_buffer_setup_ops xadc_buffer_ops = {
807 	.preenable = &xadc_preenable,
808 	.postenable = &iio_triggered_buffer_postenable,
809 	.predisable = &iio_triggered_buffer_predisable,
810 	.postdisable = &xadc_postdisable,
811 };
812 
813 static int xadc_read_raw(struct iio_dev *indio_dev,
814 	struct iio_chan_spec const *chan, int *val, int *val2, long info)
815 {
816 	struct xadc *xadc = iio_priv(indio_dev);
817 	unsigned int div;
818 	uint16_t val16;
819 	int ret;
820 
821 	switch (info) {
822 	case IIO_CHAN_INFO_RAW:
823 		if (iio_buffer_enabled(indio_dev))
824 			return -EBUSY;
825 		ret = xadc_read_adc_reg(xadc, chan->address, &val16);
826 		if (ret < 0)
827 			return ret;
828 
829 		val16 >>= 4;
830 		if (chan->scan_type.sign == 'u')
831 			*val = val16;
832 		else
833 			*val = sign_extend32(val16, 11);
834 
835 		return IIO_VAL_INT;
836 	case IIO_CHAN_INFO_SCALE:
837 		switch (chan->type) {
838 		case IIO_VOLTAGE:
839 			/* V = (val * 3.0) / 4096 */
840 			switch (chan->address) {
841 			case XADC_REG_VCCINT:
842 			case XADC_REG_VCCAUX:
843 			case XADC_REG_VREFP:
844 			case XADC_REG_VREFN:
845 			case XADC_REG_VCCBRAM:
846 			case XADC_REG_VCCPINT:
847 			case XADC_REG_VCCPAUX:
848 			case XADC_REG_VCCO_DDR:
849 				*val = 3000;
850 				break;
851 			default:
852 				*val = 1000;
853 				break;
854 			}
855 			*val2 = 12;
856 			return IIO_VAL_FRACTIONAL_LOG2;
857 		case IIO_TEMP:
858 			/* Temp in C = (val * 503.975) / 4096 - 273.15 */
859 			*val = 503975;
860 			*val2 = 12;
861 			return IIO_VAL_FRACTIONAL_LOG2;
862 		default:
863 			return -EINVAL;
864 		}
865 	case IIO_CHAN_INFO_OFFSET:
866 		/* Only the temperature channel has an offset */
867 		*val = -((273150 << 12) / 503975);
868 		return IIO_VAL_INT;
869 	case IIO_CHAN_INFO_SAMP_FREQ:
870 		ret = xadc_read_adc_reg(xadc, XADC_REG_CONF2, &val16);
871 		if (ret)
872 			return ret;
873 
874 		div = (val16 & XADC_CONF2_DIV_MASK) >> XADC_CONF2_DIV_OFFSET;
875 		if (div < 2)
876 			div = 2;
877 
878 		*val = xadc_get_dclk_rate(xadc) / div / 26;
879 
880 		return IIO_VAL_INT;
881 	default:
882 		return -EINVAL;
883 	}
884 }
885 
886 static int xadc_write_raw(struct iio_dev *indio_dev,
887 	struct iio_chan_spec const *chan, int val, int val2, long info)
888 {
889 	struct xadc *xadc = iio_priv(indio_dev);
890 	unsigned long clk_rate = xadc_get_dclk_rate(xadc);
891 	unsigned int div;
892 
893 	if (info != IIO_CHAN_INFO_SAMP_FREQ)
894 		return -EINVAL;
895 
896 	if (val <= 0)
897 		return -EINVAL;
898 
899 	/* Max. 150 kSPS */
900 	if (val > 150000)
901 		val = 150000;
902 
903 	val *= 26;
904 
905 	/* Min 1MHz */
906 	if (val < 1000000)
907 		val = 1000000;
908 
909 	/*
910 	 * We want to round down, but only if we do not exceed the 150 kSPS
911 	 * limit.
912 	 */
913 	div = clk_rate / val;
914 	if (clk_rate / div / 26 > 150000)
915 		div++;
916 	if (div < 2)
917 		div = 2;
918 	else if (div > 0xff)
919 		div = 0xff;
920 
921 	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_DIV_MASK,
922 		div << XADC_CONF2_DIV_OFFSET);
923 }
924 
925 static const struct iio_event_spec xadc_temp_events[] = {
926 	{
927 		.type = IIO_EV_TYPE_THRESH,
928 		.dir = IIO_EV_DIR_RISING,
929 		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
930 				BIT(IIO_EV_INFO_VALUE) |
931 				BIT(IIO_EV_INFO_HYSTERESIS),
932 	},
933 };
934 
935 /* Separate values for upper and lower thresholds, but only a shared enabled */
936 static const struct iio_event_spec xadc_voltage_events[] = {
937 	{
938 		.type = IIO_EV_TYPE_THRESH,
939 		.dir = IIO_EV_DIR_RISING,
940 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
941 	}, {
942 		.type = IIO_EV_TYPE_THRESH,
943 		.dir = IIO_EV_DIR_FALLING,
944 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
945 	}, {
946 		.type = IIO_EV_TYPE_THRESH,
947 		.dir = IIO_EV_DIR_EITHER,
948 		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
949 	},
950 };
951 
952 #define XADC_CHAN_TEMP(_chan, _scan_index, _addr) { \
953 	.type = IIO_TEMP, \
954 	.indexed = 1, \
955 	.channel = (_chan), \
956 	.address = (_addr), \
957 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
958 		BIT(IIO_CHAN_INFO_SCALE) | \
959 		BIT(IIO_CHAN_INFO_OFFSET), \
960 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
961 	.event_spec = xadc_temp_events, \
962 	.num_event_specs = ARRAY_SIZE(xadc_temp_events), \
963 	.scan_index = (_scan_index), \
964 	.scan_type = { \
965 		.sign = 'u', \
966 		.realbits = 12, \
967 		.storagebits = 16, \
968 		.shift = 4, \
969 		.endianness = IIO_CPU, \
970 	}, \
971 }
972 
973 #define XADC_CHAN_VOLTAGE(_chan, _scan_index, _addr, _ext, _alarm) { \
974 	.type = IIO_VOLTAGE, \
975 	.indexed = 1, \
976 	.channel = (_chan), \
977 	.address = (_addr), \
978 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
979 		BIT(IIO_CHAN_INFO_SCALE), \
980 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
981 	.event_spec = (_alarm) ? xadc_voltage_events : NULL, \
982 	.num_event_specs = (_alarm) ? ARRAY_SIZE(xadc_voltage_events) : 0, \
983 	.scan_index = (_scan_index), \
984 	.scan_type = { \
985 		.sign = ((_addr) == XADC_REG_VREFN) ? 's' : 'u', \
986 		.realbits = 12, \
987 		.storagebits = 16, \
988 		.shift = 4, \
989 		.endianness = IIO_CPU, \
990 	}, \
991 	.extend_name = _ext, \
992 }
993 
994 static const struct iio_chan_spec xadc_channels[] = {
995 	XADC_CHAN_TEMP(0, 8, XADC_REG_TEMP),
996 	XADC_CHAN_VOLTAGE(0, 9, XADC_REG_VCCINT, "vccint", true),
997 	XADC_CHAN_VOLTAGE(1, 10, XADC_REG_VCCAUX, "vccaux", true),
998 	XADC_CHAN_VOLTAGE(2, 14, XADC_REG_VCCBRAM, "vccbram", true),
999 	XADC_CHAN_VOLTAGE(3, 5, XADC_REG_VCCPINT, "vccpint", true),
1000 	XADC_CHAN_VOLTAGE(4, 6, XADC_REG_VCCPAUX, "vccpaux", true),
1001 	XADC_CHAN_VOLTAGE(5, 7, XADC_REG_VCCO_DDR, "vccoddr", true),
1002 	XADC_CHAN_VOLTAGE(6, 12, XADC_REG_VREFP, "vrefp", false),
1003 	XADC_CHAN_VOLTAGE(7, 13, XADC_REG_VREFN, "vrefn", false),
1004 	XADC_CHAN_VOLTAGE(8, 11, XADC_REG_VPVN, NULL, false),
1005 	XADC_CHAN_VOLTAGE(9, 16, XADC_REG_VAUX(0), NULL, false),
1006 	XADC_CHAN_VOLTAGE(10, 17, XADC_REG_VAUX(1), NULL, false),
1007 	XADC_CHAN_VOLTAGE(11, 18, XADC_REG_VAUX(2), NULL, false),
1008 	XADC_CHAN_VOLTAGE(12, 19, XADC_REG_VAUX(3), NULL, false),
1009 	XADC_CHAN_VOLTAGE(13, 20, XADC_REG_VAUX(4), NULL, false),
1010 	XADC_CHAN_VOLTAGE(14, 21, XADC_REG_VAUX(5), NULL, false),
1011 	XADC_CHAN_VOLTAGE(15, 22, XADC_REG_VAUX(6), NULL, false),
1012 	XADC_CHAN_VOLTAGE(16, 23, XADC_REG_VAUX(7), NULL, false),
1013 	XADC_CHAN_VOLTAGE(17, 24, XADC_REG_VAUX(8), NULL, false),
1014 	XADC_CHAN_VOLTAGE(18, 25, XADC_REG_VAUX(9), NULL, false),
1015 	XADC_CHAN_VOLTAGE(19, 26, XADC_REG_VAUX(10), NULL, false),
1016 	XADC_CHAN_VOLTAGE(20, 27, XADC_REG_VAUX(11), NULL, false),
1017 	XADC_CHAN_VOLTAGE(21, 28, XADC_REG_VAUX(12), NULL, false),
1018 	XADC_CHAN_VOLTAGE(22, 29, XADC_REG_VAUX(13), NULL, false),
1019 	XADC_CHAN_VOLTAGE(23, 30, XADC_REG_VAUX(14), NULL, false),
1020 	XADC_CHAN_VOLTAGE(24, 31, XADC_REG_VAUX(15), NULL, false),
1021 };
1022 
1023 static const struct iio_info xadc_info = {
1024 	.read_raw = &xadc_read_raw,
1025 	.write_raw = &xadc_write_raw,
1026 	.read_event_config = &xadc_read_event_config,
1027 	.write_event_config = &xadc_write_event_config,
1028 	.read_event_value = &xadc_read_event_value,
1029 	.write_event_value = &xadc_write_event_value,
1030 	.update_scan_mode = &xadc_update_scan_mode,
1031 	.driver_module = THIS_MODULE,
1032 };
1033 
1034 static const struct of_device_id xadc_of_match_table[] = {
1035 	{ .compatible = "xlnx,zynq-xadc-1.00.a", (void *)&xadc_zynq_ops },
1036 	{ .compatible = "xlnx,axi-xadc-1.00.a", (void *)&xadc_axi_ops },
1037 	{ },
1038 };
1039 MODULE_DEVICE_TABLE(of, xadc_of_match_table);
1040 
1041 static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
1042 	unsigned int *conf)
1043 {
1044 	struct xadc *xadc = iio_priv(indio_dev);
1045 	struct iio_chan_spec *channels, *chan;
1046 	struct device_node *chan_node, *child;
1047 	unsigned int num_channels;
1048 	const char *external_mux;
1049 	u32 ext_mux_chan;
1050 	int reg;
1051 	int ret;
1052 
1053 	*conf = 0;
1054 
1055 	ret = of_property_read_string(np, "xlnx,external-mux", &external_mux);
1056 	if (ret < 0 || strcasecmp(external_mux, "none") == 0)
1057 		xadc->external_mux_mode = XADC_EXTERNAL_MUX_NONE;
1058 	else if (strcasecmp(external_mux, "single") == 0)
1059 		xadc->external_mux_mode = XADC_EXTERNAL_MUX_SINGLE;
1060 	else if (strcasecmp(external_mux, "dual") == 0)
1061 		xadc->external_mux_mode = XADC_EXTERNAL_MUX_DUAL;
1062 	else
1063 		return -EINVAL;
1064 
1065 	if (xadc->external_mux_mode != XADC_EXTERNAL_MUX_NONE) {
1066 		ret = of_property_read_u32(np, "xlnx,external-mux-channel",
1067 					&ext_mux_chan);
1068 		if (ret < 0)
1069 			return ret;
1070 
1071 		if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_SINGLE) {
1072 			if (ext_mux_chan == 0)
1073 				ext_mux_chan = XADC_REG_VPVN;
1074 			else if (ext_mux_chan <= 16)
1075 				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1076 			else
1077 				return -EINVAL;
1078 		} else {
1079 			if (ext_mux_chan > 0 && ext_mux_chan <= 8)
1080 				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1081 			else
1082 				return -EINVAL;
1083 		}
1084 
1085 		*conf |= XADC_CONF0_MUX | XADC_CONF0_CHAN(ext_mux_chan);
1086 	}
1087 
1088 	channels = kmemdup(xadc_channels, sizeof(xadc_channels), GFP_KERNEL);
1089 	if (!channels)
1090 		return -ENOMEM;
1091 
1092 	num_channels = 9;
1093 	chan = &channels[9];
1094 
1095 	chan_node = of_get_child_by_name(np, "xlnx,channels");
1096 	if (chan_node) {
1097 		for_each_child_of_node(chan_node, child) {
1098 			if (num_channels >= ARRAY_SIZE(xadc_channels)) {
1099 				of_node_put(child);
1100 				break;
1101 			}
1102 
1103 			ret = of_property_read_u32(child, "reg", &reg);
1104 			if (ret || reg > 16)
1105 				continue;
1106 
1107 			if (of_property_read_bool(child, "xlnx,bipolar"))
1108 				chan->scan_type.sign = 's';
1109 
1110 			if (reg == 0) {
1111 				chan->scan_index = 11;
1112 				chan->address = XADC_REG_VPVN;
1113 			} else {
1114 				chan->scan_index = 15 + reg;
1115 				chan->address = XADC_REG_VAUX(reg - 1);
1116 			}
1117 			num_channels++;
1118 			chan++;
1119 		}
1120 	}
1121 	of_node_put(chan_node);
1122 
1123 	indio_dev->num_channels = num_channels;
1124 	indio_dev->channels = krealloc(channels, sizeof(*channels) *
1125 					num_channels, GFP_KERNEL);
1126 	/* If we can't resize the channels array, just use the original */
1127 	if (!indio_dev->channels)
1128 		indio_dev->channels = channels;
1129 
1130 	return 0;
1131 }
1132 
1133 static int xadc_probe(struct platform_device *pdev)
1134 {
1135 	const struct of_device_id *id;
1136 	struct iio_dev *indio_dev;
1137 	unsigned int bipolar_mask;
1138 	struct resource *mem;
1139 	unsigned int conf0;
1140 	struct xadc *xadc;
1141 	int ret;
1142 	int irq;
1143 	int i;
1144 
1145 	if (!pdev->dev.of_node)
1146 		return -ENODEV;
1147 
1148 	id = of_match_node(xadc_of_match_table, pdev->dev.of_node);
1149 	if (!id)
1150 		return -EINVAL;
1151 
1152 	irq = platform_get_irq(pdev, 0);
1153 	if (irq <= 0)
1154 		return -ENXIO;
1155 
1156 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*xadc));
1157 	if (!indio_dev)
1158 		return -ENOMEM;
1159 
1160 	xadc = iio_priv(indio_dev);
1161 	xadc->ops = id->data;
1162 	init_completion(&xadc->completion);
1163 	mutex_init(&xadc->mutex);
1164 	spin_lock_init(&xadc->lock);
1165 	INIT_DELAYED_WORK(&xadc->zynq_unmask_work, xadc_zynq_unmask_worker);
1166 
1167 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1168 	xadc->base = devm_ioremap_resource(&pdev->dev, mem);
1169 	if (IS_ERR(xadc->base))
1170 		return PTR_ERR(xadc->base);
1171 
1172 	indio_dev->dev.parent = &pdev->dev;
1173 	indio_dev->dev.of_node = pdev->dev.of_node;
1174 	indio_dev->name = "xadc";
1175 	indio_dev->modes = INDIO_DIRECT_MODE;
1176 	indio_dev->info = &xadc_info;
1177 
1178 	ret = xadc_parse_dt(indio_dev, pdev->dev.of_node, &conf0);
1179 	if (ret)
1180 		goto err_device_free;
1181 
1182 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1183 		ret = iio_triggered_buffer_setup(indio_dev,
1184 			&iio_pollfunc_store_time, &xadc_trigger_handler,
1185 			&xadc_buffer_ops);
1186 		if (ret)
1187 			goto err_device_free;
1188 
1189 		xadc->convst_trigger = xadc_alloc_trigger(indio_dev, "convst");
1190 		if (IS_ERR(xadc->convst_trigger)) {
1191 			ret = PTR_ERR(xadc->convst_trigger);
1192 			goto err_triggered_buffer_cleanup;
1193 		}
1194 		xadc->samplerate_trigger = xadc_alloc_trigger(indio_dev,
1195 			"samplerate");
1196 		if (IS_ERR(xadc->samplerate_trigger)) {
1197 			ret = PTR_ERR(xadc->samplerate_trigger);
1198 			goto err_free_convst_trigger;
1199 		}
1200 	}
1201 
1202 	xadc->clk = devm_clk_get(&pdev->dev, NULL);
1203 	if (IS_ERR(xadc->clk)) {
1204 		ret = PTR_ERR(xadc->clk);
1205 		goto err_free_samplerate_trigger;
1206 	}
1207 	clk_prepare_enable(xadc->clk);
1208 
1209 	ret = xadc->ops->setup(pdev, indio_dev, irq);
1210 	if (ret)
1211 		goto err_free_samplerate_trigger;
1212 
1213 	ret = request_irq(irq, xadc->ops->interrupt_handler, 0,
1214 			dev_name(&pdev->dev), indio_dev);
1215 	if (ret)
1216 		goto err_clk_disable_unprepare;
1217 
1218 	for (i = 0; i < 16; i++)
1219 		xadc_read_adc_reg(xadc, XADC_REG_THRESHOLD(i),
1220 			&xadc->threshold[i]);
1221 
1222 	ret = xadc_write_adc_reg(xadc, XADC_REG_CONF0, conf0);
1223 	if (ret)
1224 		goto err_free_irq;
1225 
1226 	bipolar_mask = 0;
1227 	for (i = 0; i < indio_dev->num_channels; i++) {
1228 		if (indio_dev->channels[i].scan_type.sign == 's')
1229 			bipolar_mask |= BIT(indio_dev->channels[i].scan_index);
1230 	}
1231 
1232 	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(0), bipolar_mask);
1233 	if (ret)
1234 		goto err_free_irq;
1235 	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(1),
1236 		bipolar_mask >> 16);
1237 	if (ret)
1238 		goto err_free_irq;
1239 
1240 	/* Disable all alarms */
1241 	xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_ALARM_MASK,
1242 		XADC_CONF1_ALARM_MASK);
1243 
1244 	/* Set thresholds to min/max */
1245 	for (i = 0; i < 16; i++) {
1246 		/*
1247 		 * Set max voltage threshold and both temperature thresholds to
1248 		 * 0xffff, min voltage threshold to 0.
1249 		 */
1250 		if (i % 8 < 4 || i == 7)
1251 			xadc->threshold[i] = 0xffff;
1252 		else
1253 			xadc->threshold[i] = 0;
1254 		xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(i),
1255 			xadc->threshold[i]);
1256 	}
1257 
1258 	/* Go to non-buffered mode */
1259 	xadc_postdisable(indio_dev);
1260 
1261 	ret = iio_device_register(indio_dev);
1262 	if (ret)
1263 		goto err_free_irq;
1264 
1265 	platform_set_drvdata(pdev, indio_dev);
1266 
1267 	return 0;
1268 
1269 err_free_irq:
1270 	free_irq(irq, indio_dev);
1271 err_free_samplerate_trigger:
1272 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1273 		iio_trigger_free(xadc->samplerate_trigger);
1274 err_free_convst_trigger:
1275 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1276 		iio_trigger_free(xadc->convst_trigger);
1277 err_triggered_buffer_cleanup:
1278 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1279 		iio_triggered_buffer_cleanup(indio_dev);
1280 err_clk_disable_unprepare:
1281 	clk_disable_unprepare(xadc->clk);
1282 err_device_free:
1283 	kfree(indio_dev->channels);
1284 
1285 	return ret;
1286 }
1287 
1288 static int xadc_remove(struct platform_device *pdev)
1289 {
1290 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1291 	struct xadc *xadc = iio_priv(indio_dev);
1292 	int irq = platform_get_irq(pdev, 0);
1293 
1294 	iio_device_unregister(indio_dev);
1295 	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1296 		iio_trigger_free(xadc->samplerate_trigger);
1297 		iio_trigger_free(xadc->convst_trigger);
1298 		iio_triggered_buffer_cleanup(indio_dev);
1299 	}
1300 	free_irq(irq, indio_dev);
1301 	clk_disable_unprepare(xadc->clk);
1302 	cancel_delayed_work(&xadc->zynq_unmask_work);
1303 	kfree(xadc->data);
1304 	kfree(indio_dev->channels);
1305 
1306 	return 0;
1307 }
1308 
1309 static struct platform_driver xadc_driver = {
1310 	.probe = xadc_probe,
1311 	.remove = xadc_remove,
1312 	.driver = {
1313 		.name = "xadc",
1314 		.of_match_table = xadc_of_match_table,
1315 	},
1316 };
1317 module_platform_driver(xadc_driver);
1318 
1319 MODULE_LICENSE("GPL v2");
1320 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1321 MODULE_DESCRIPTION("Xilinx XADC IIO driver");
1322