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
37static 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
106static void xadc_write_reg(struct xadc *xadc, unsigned int reg,
107	uint32_t val)
108{
109	writel(val, xadc->base + reg);
110}
111
112static 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
128static 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
137static 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
149static 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
159static 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
193static 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
231static 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 */
246static 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
278static irqreturn_t xadc_zynq_threaded_interrupt_handler(int irq, void *devid)
279{
280	struct iio_dev *indio_dev = devid;
281	struct xadc *xadc = iio_priv(indio_dev);
282	unsigned int alarm;
283
284	spin_lock_irq(&xadc->lock);
285	alarm = xadc->zynq_alarm;
286	xadc->zynq_alarm = 0;
287	spin_unlock_irq(&xadc->lock);
288
289	xadc_handle_events(indio_dev, xadc_zynq_transform_alarm(alarm));
290
291	/* unmask the required interrupts in timer. */
292	schedule_delayed_work(&xadc->zynq_unmask_work,
293			msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT));
294
295	return IRQ_HANDLED;
296}
297
298static irqreturn_t xadc_zynq_interrupt_handler(int irq, void *devid)
299{
300	struct iio_dev *indio_dev = devid;
301	struct xadc *xadc = iio_priv(indio_dev);
302	irqreturn_t ret = IRQ_HANDLED;
303	uint32_t status;
304
305	xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
306
307	status &= ~(xadc->zynq_intmask | xadc->zynq_masked_alarm);
308
309	if (!status)
310		return IRQ_NONE;
311
312	spin_lock(&xadc->lock);
313
314	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status);
315
316	if (status & XADC_ZYNQ_INT_DFIFO_GTH) {
317		xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
318			XADC_ZYNQ_INT_DFIFO_GTH);
319		complete(&xadc->completion);
320	}
321
322	status &= XADC_ZYNQ_INT_ALARM_MASK;
323	if (status) {
324		xadc->zynq_alarm |= status;
325		xadc->zynq_masked_alarm |= status;
326		/*
327		 * mask the current event interrupt,
328		 * unmask it when the interrupt is no more active.
329		 */
330		xadc_zynq_update_intmsk(xadc, 0, 0);
331		ret = IRQ_WAKE_THREAD;
332	}
333	spin_unlock(&xadc->lock);
334
335	return ret;
336}
337
338#define XADC_ZYNQ_TCK_RATE_MAX 50000000
339#define XADC_ZYNQ_IGAP_DEFAULT 20
340
341static int xadc_zynq_setup(struct platform_device *pdev,
342	struct iio_dev *indio_dev, int irq)
343{
344	struct xadc *xadc = iio_priv(indio_dev);
345	unsigned long pcap_rate;
346	unsigned int tck_div;
347	unsigned int div;
348	unsigned int igap;
349	unsigned int tck_rate;
350
351	/* TODO: Figure out how to make igap and tck_rate configurable */
352	igap = XADC_ZYNQ_IGAP_DEFAULT;
353	tck_rate = XADC_ZYNQ_TCK_RATE_MAX;
354
355	xadc->zynq_intmask = ~0;
356
357	pcap_rate = clk_get_rate(xadc->clk);
358
359	if (tck_rate > XADC_ZYNQ_TCK_RATE_MAX)
360		tck_rate = XADC_ZYNQ_TCK_RATE_MAX;
361	if (tck_rate > pcap_rate / 2) {
362		div = 2;
363	} else {
364		div = pcap_rate / tck_rate;
365		if (pcap_rate / div > XADC_ZYNQ_TCK_RATE_MAX)
366			div++;
367	}
368
369	if (div <= 3)
370		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV2;
371	else if (div <= 7)
372		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV4;
373	else if (div <= 15)
374		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV8;
375	else
376		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV16;
377
378	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, XADC_ZYNQ_CTL_RESET);
379	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, 0);
380	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, ~0);
381	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK, xadc->zynq_intmask);
382	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, XADC_ZYNQ_CFG_ENABLE |
383			XADC_ZYNQ_CFG_REDGE | XADC_ZYNQ_CFG_WEDGE |
384			tck_div | XADC_ZYNQ_CFG_IGAP(igap));
385
386	return 0;
387}
388
389static 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
414static 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
434static 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	.threaded_interrupt_handler = xadc_zynq_threaded_interrupt_handler,
441	.update_alarm = xadc_zynq_update_alarm,
442};
443
444static int xadc_axi_read_adc_reg(struct xadc *xadc, unsigned int reg,
445	uint16_t *val)
446{
447	uint32_t val32;
448
449	xadc_read_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, &val32);
450	*val = val32 & 0xffff;
451
452	return 0;
453}
454
455static int xadc_axi_write_adc_reg(struct xadc *xadc, unsigned int reg,
456	uint16_t val)
457{
458	xadc_write_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, val);
459
460	return 0;
461}
462
463static int xadc_axi_setup(struct platform_device *pdev,
464	struct iio_dev *indio_dev, int irq)
465{
466	struct xadc *xadc = iio_priv(indio_dev);
467
468	xadc_write_reg(xadc, XADC_AXI_REG_RESET, XADC_AXI_RESET_MAGIC);
469	xadc_write_reg(xadc, XADC_AXI_REG_GIER, XADC_AXI_GIER_ENABLE);
470
471	return 0;
472}
473
474static irqreturn_t xadc_axi_interrupt_handler(int irq, void *devid)
475{
476	struct iio_dev *indio_dev = devid;
477	struct xadc *xadc = iio_priv(indio_dev);
478	uint32_t status, mask;
479	unsigned int events;
480
481	xadc_read_reg(xadc, XADC_AXI_REG_IPISR, &status);
482	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &mask);
483	status &= mask;
484
485	if (!status)
486		return IRQ_NONE;
487
488	if ((status & XADC_AXI_INT_EOS) && xadc->trigger)
489		iio_trigger_poll(xadc->trigger);
490
491	if (status & XADC_AXI_INT_ALARM_MASK) {
492		/*
493		 * The order of the bits in the AXI-XADC status register does
494		 * not match the order of the bits in the XADC alarm enable
495		 * register. xadc_handle_events() expects the events to be in
496		 * the same order as the XADC alarm enable register.
497		 */
498		events = (status & 0x000e) >> 1;
499		events |= (status & 0x0001) << 3;
500		events |= (status & 0x3c00) >> 6;
501		xadc_handle_events(indio_dev, events);
502	}
503
504	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, status);
505
506	return IRQ_HANDLED;
507}
508
509static void xadc_axi_update_alarm(struct xadc *xadc, unsigned int alarm)
510{
511	uint32_t val;
512	unsigned long flags;
513
514	/*
515	 * The order of the bits in the AXI-XADC status register does not match
516	 * the order of the bits in the XADC alarm enable register. We get
517	 * passed the alarm mask in the same order as in the XADC alarm enable
518	 * register.
519	 */
520	alarm = ((alarm & 0x07) << 1) | ((alarm & 0x08) >> 3) |
521			((alarm & 0xf0) << 6);
522
523	spin_lock_irqsave(&xadc->lock, flags);
524	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
525	val &= ~XADC_AXI_INT_ALARM_MASK;
526	val |= alarm;
527	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
528	spin_unlock_irqrestore(&xadc->lock, flags);
529}
530
531static unsigned long xadc_axi_get_dclk(struct xadc *xadc)
532{
533	return clk_get_rate(xadc->clk);
534}
535
536static const struct xadc_ops xadc_axi_ops = {
537	.read = xadc_axi_read_adc_reg,
538	.write = xadc_axi_write_adc_reg,
539	.setup = xadc_axi_setup,
540	.get_dclk_rate = xadc_axi_get_dclk,
541	.update_alarm = xadc_axi_update_alarm,
542	.interrupt_handler = xadc_axi_interrupt_handler,
543	.flags = XADC_FLAGS_BUFFERED,
544};
545
546static int _xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
547	uint16_t mask, uint16_t val)
548{
549	uint16_t tmp;
550	int ret;
551
552	ret = _xadc_read_adc_reg(xadc, reg, &tmp);
553	if (ret)
554		return ret;
555
556	return _xadc_write_adc_reg(xadc, reg, (tmp & ~mask) | val);
557}
558
559static int xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
560	uint16_t mask, uint16_t val)
561{
562	int ret;
563
564	mutex_lock(&xadc->mutex);
565	ret = _xadc_update_adc_reg(xadc, reg, mask, val);
566	mutex_unlock(&xadc->mutex);
567
568	return ret;
569}
570
571static unsigned long xadc_get_dclk_rate(struct xadc *xadc)
572{
573	return xadc->ops->get_dclk_rate(xadc);
574}
575
576static int xadc_update_scan_mode(struct iio_dev *indio_dev,
577	const unsigned long *mask)
578{
579	struct xadc *xadc = iio_priv(indio_dev);
580	unsigned int n;
581
582	n = bitmap_weight(mask, indio_dev->masklength);
583
584	kfree(xadc->data);
585	xadc->data = kcalloc(n, sizeof(*xadc->data), GFP_KERNEL);
586	if (!xadc->data)
587		return -ENOMEM;
588
589	return 0;
590}
591
592static unsigned int xadc_scan_index_to_channel(unsigned int scan_index)
593{
594	switch (scan_index) {
595	case 5:
596		return XADC_REG_VCCPINT;
597	case 6:
598		return XADC_REG_VCCPAUX;
599	case 7:
600		return XADC_REG_VCCO_DDR;
601	case 8:
602		return XADC_REG_TEMP;
603	case 9:
604		return XADC_REG_VCCINT;
605	case 10:
606		return XADC_REG_VCCAUX;
607	case 11:
608		return XADC_REG_VPVN;
609	case 12:
610		return XADC_REG_VREFP;
611	case 13:
612		return XADC_REG_VREFN;
613	case 14:
614		return XADC_REG_VCCBRAM;
615	default:
616		return XADC_REG_VAUX(scan_index - 16);
617	}
618}
619
620static irqreturn_t xadc_trigger_handler(int irq, void *p)
621{
622	struct iio_poll_func *pf = p;
623	struct iio_dev *indio_dev = pf->indio_dev;
624	struct xadc *xadc = iio_priv(indio_dev);
625	unsigned int chan;
626	int i, j;
627
628	if (!xadc->data)
629		goto out;
630
631	j = 0;
632	for_each_set_bit(i, indio_dev->active_scan_mask,
633		indio_dev->masklength) {
634		chan = xadc_scan_index_to_channel(i);
635		xadc_read_adc_reg(xadc, chan, &xadc->data[j]);
636		j++;
637	}
638
639	iio_push_to_buffers(indio_dev, xadc->data);
640
641out:
642	iio_trigger_notify_done(indio_dev->trig);
643
644	return IRQ_HANDLED;
645}
646
647static int xadc_trigger_set_state(struct iio_trigger *trigger, bool state)
648{
649	struct xadc *xadc = iio_trigger_get_drvdata(trigger);
650	unsigned long flags;
651	unsigned int convst;
652	unsigned int val;
653	int ret = 0;
654
655	mutex_lock(&xadc->mutex);
656
657	if (state) {
658		/* Only one of the two triggers can be active at the a time. */
659		if (xadc->trigger != NULL) {
660			ret = -EBUSY;
661			goto err_out;
662		} else {
663			xadc->trigger = trigger;
664			if (trigger == xadc->convst_trigger)
665				convst = XADC_CONF0_EC;
666			else
667				convst = 0;
668		}
669		ret = _xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF0_EC,
670					convst);
671		if (ret)
672			goto err_out;
673	} else {
674		xadc->trigger = NULL;
675	}
676
677	spin_lock_irqsave(&xadc->lock, flags);
678	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
679	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, val & XADC_AXI_INT_EOS);
680	if (state)
681		val |= XADC_AXI_INT_EOS;
682	else
683		val &= ~XADC_AXI_INT_EOS;
684	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
685	spin_unlock_irqrestore(&xadc->lock, flags);
686
687err_out:
688	mutex_unlock(&xadc->mutex);
689
690	return ret;
691}
692
693static const struct iio_trigger_ops xadc_trigger_ops = {
694	.owner = THIS_MODULE,
695	.set_trigger_state = &xadc_trigger_set_state,
696};
697
698static struct iio_trigger *xadc_alloc_trigger(struct iio_dev *indio_dev,
699	const char *name)
700{
701	struct iio_trigger *trig;
702	int ret;
703
704	trig = iio_trigger_alloc("%s%d-%s", indio_dev->name,
705				indio_dev->id, name);
706	if (trig == NULL)
707		return ERR_PTR(-ENOMEM);
708
709	trig->dev.parent = indio_dev->dev.parent;
710	trig->ops = &xadc_trigger_ops;
711	iio_trigger_set_drvdata(trig, iio_priv(indio_dev));
712
713	ret = iio_trigger_register(trig);
714	if (ret)
715		goto error_free_trig;
716
717	return trig;
718
719error_free_trig:
720	iio_trigger_free(trig);
721	return ERR_PTR(ret);
722}
723
724static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode)
725{
726	uint16_t val;
727
728	switch (seq_mode) {
729	case XADC_CONF1_SEQ_SIMULTANEOUS:
730	case XADC_CONF1_SEQ_INDEPENDENT:
731		val = XADC_CONF2_PD_ADC_B;
732		break;
733	default:
734		val = 0;
735		break;
736	}
737
738	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_PD_MASK,
739		val);
740}
741
742static int xadc_get_seq_mode(struct xadc *xadc, unsigned long scan_mode)
743{
744	unsigned int aux_scan_mode = scan_mode >> 16;
745
746	if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_DUAL)
747		return XADC_CONF1_SEQ_SIMULTANEOUS;
748
749	if ((aux_scan_mode & 0xff00) == 0 ||
750		(aux_scan_mode & 0x00ff) == 0)
751		return XADC_CONF1_SEQ_CONTINUOUS;
752
753	return XADC_CONF1_SEQ_SIMULTANEOUS;
754}
755
756static int xadc_postdisable(struct iio_dev *indio_dev)
757{
758	struct xadc *xadc = iio_priv(indio_dev);
759	unsigned long scan_mask;
760	int ret;
761	int i;
762
763	scan_mask = 1; /* Run calibration as part of the sequence */
764	for (i = 0; i < indio_dev->num_channels; i++)
765		scan_mask |= BIT(indio_dev->channels[i].scan_index);
766
767	/* Enable all channels and calibration */
768	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
769	if (ret)
770		return ret;
771
772	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
773	if (ret)
774		return ret;
775
776	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
777		XADC_CONF1_SEQ_CONTINUOUS);
778	if (ret)
779		return ret;
780
781	return xadc_power_adc_b(xadc, XADC_CONF1_SEQ_CONTINUOUS);
782}
783
784static int xadc_preenable(struct iio_dev *indio_dev)
785{
786	struct xadc *xadc = iio_priv(indio_dev);
787	unsigned long scan_mask;
788	int seq_mode;
789	int ret;
790
791	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
792		XADC_CONF1_SEQ_DEFAULT);
793	if (ret)
794		goto err;
795
796	scan_mask = *indio_dev->active_scan_mask;
797	seq_mode = xadc_get_seq_mode(xadc, scan_mask);
798
799	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
800	if (ret)
801		goto err;
802
803	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
804	if (ret)
805		goto err;
806
807	ret = xadc_power_adc_b(xadc, seq_mode);
808	if (ret)
809		goto err;
810
811	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
812		seq_mode);
813	if (ret)
814		goto err;
815
816	return 0;
817err:
818	xadc_postdisable(indio_dev);
819	return ret;
820}
821
822static struct iio_buffer_setup_ops xadc_buffer_ops = {
823	.preenable = &xadc_preenable,
824	.postenable = &iio_triggered_buffer_postenable,
825	.predisable = &iio_triggered_buffer_predisable,
826	.postdisable = &xadc_postdisable,
827};
828
829static int xadc_read_raw(struct iio_dev *indio_dev,
830	struct iio_chan_spec const *chan, int *val, int *val2, long info)
831{
832	struct xadc *xadc = iio_priv(indio_dev);
833	unsigned int div;
834	uint16_t val16;
835	int ret;
836
837	switch (info) {
838	case IIO_CHAN_INFO_RAW:
839		if (iio_buffer_enabled(indio_dev))
840			return -EBUSY;
841		ret = xadc_read_adc_reg(xadc, chan->address, &val16);
842		if (ret < 0)
843			return ret;
844
845		val16 >>= 4;
846		if (chan->scan_type.sign == 'u')
847			*val = val16;
848		else
849			*val = sign_extend32(val16, 11);
850
851		return IIO_VAL_INT;
852	case IIO_CHAN_INFO_SCALE:
853		switch (chan->type) {
854		case IIO_VOLTAGE:
855			/* V = (val * 3.0) / 4096 */
856			switch (chan->address) {
857			case XADC_REG_VCCINT:
858			case XADC_REG_VCCAUX:
859			case XADC_REG_VREFP:
860			case XADC_REG_VCCBRAM:
861			case XADC_REG_VCCPINT:
862			case XADC_REG_VCCPAUX:
863			case XADC_REG_VCCO_DDR:
864				*val = 3000;
865				break;
866			default:
867				*val = 1000;
868				break;
869			}
870			*val2 = 12;
871			return IIO_VAL_FRACTIONAL_LOG2;
872		case IIO_TEMP:
873			/* Temp in C = (val * 503.975) / 4096 - 273.15 */
874			*val = 503975;
875			*val2 = 12;
876			return IIO_VAL_FRACTIONAL_LOG2;
877		default:
878			return -EINVAL;
879		}
880	case IIO_CHAN_INFO_OFFSET:
881		/* Only the temperature channel has an offset */
882		*val = -((273150 << 12) / 503975);
883		return IIO_VAL_INT;
884	case IIO_CHAN_INFO_SAMP_FREQ:
885		ret = xadc_read_adc_reg(xadc, XADC_REG_CONF2, &val16);
886		if (ret)
887			return ret;
888
889		div = (val16 & XADC_CONF2_DIV_MASK) >> XADC_CONF2_DIV_OFFSET;
890		if (div < 2)
891			div = 2;
892
893		*val = xadc_get_dclk_rate(xadc) / div / 26;
894
895		return IIO_VAL_INT;
896	default:
897		return -EINVAL;
898	}
899}
900
901static int xadc_write_raw(struct iio_dev *indio_dev,
902	struct iio_chan_spec const *chan, int val, int val2, long info)
903{
904	struct xadc *xadc = iio_priv(indio_dev);
905	unsigned long clk_rate = xadc_get_dclk_rate(xadc);
906	unsigned int div;
907
908	if (info != IIO_CHAN_INFO_SAMP_FREQ)
909		return -EINVAL;
910
911	if (val <= 0)
912		return -EINVAL;
913
914	/* Max. 150 kSPS */
915	if (val > 150000)
916		val = 150000;
917
918	val *= 26;
919
920	/* Min 1MHz */
921	if (val < 1000000)
922		val = 1000000;
923
924	/*
925	 * We want to round down, but only if we do not exceed the 150 kSPS
926	 * limit.
927	 */
928	div = clk_rate / val;
929	if (clk_rate / div / 26 > 150000)
930		div++;
931	if (div < 2)
932		div = 2;
933	else if (div > 0xff)
934		div = 0xff;
935
936	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_DIV_MASK,
937		div << XADC_CONF2_DIV_OFFSET);
938}
939
940static const struct iio_event_spec xadc_temp_events[] = {
941	{
942		.type = IIO_EV_TYPE_THRESH,
943		.dir = IIO_EV_DIR_RISING,
944		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
945				BIT(IIO_EV_INFO_VALUE) |
946				BIT(IIO_EV_INFO_HYSTERESIS),
947	},
948};
949
950/* Separate values for upper and lower thresholds, but only a shared enabled */
951static const struct iio_event_spec xadc_voltage_events[] = {
952	{
953		.type = IIO_EV_TYPE_THRESH,
954		.dir = IIO_EV_DIR_RISING,
955		.mask_separate = BIT(IIO_EV_INFO_VALUE),
956	}, {
957		.type = IIO_EV_TYPE_THRESH,
958		.dir = IIO_EV_DIR_FALLING,
959		.mask_separate = BIT(IIO_EV_INFO_VALUE),
960	}, {
961		.type = IIO_EV_TYPE_THRESH,
962		.dir = IIO_EV_DIR_EITHER,
963		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
964	},
965};
966
967#define XADC_CHAN_TEMP(_chan, _scan_index, _addr) { \
968	.type = IIO_TEMP, \
969	.indexed = 1, \
970	.channel = (_chan), \
971	.address = (_addr), \
972	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
973		BIT(IIO_CHAN_INFO_SCALE) | \
974		BIT(IIO_CHAN_INFO_OFFSET), \
975	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
976	.event_spec = xadc_temp_events, \
977	.num_event_specs = ARRAY_SIZE(xadc_temp_events), \
978	.scan_index = (_scan_index), \
979	.scan_type = { \
980		.sign = 'u', \
981		.realbits = 12, \
982		.storagebits = 16, \
983		.shift = 4, \
984		.endianness = IIO_CPU, \
985	}, \
986}
987
988#define XADC_CHAN_VOLTAGE(_chan, _scan_index, _addr, _ext, _alarm) { \
989	.type = IIO_VOLTAGE, \
990	.indexed = 1, \
991	.channel = (_chan), \
992	.address = (_addr), \
993	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
994		BIT(IIO_CHAN_INFO_SCALE), \
995	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
996	.event_spec = (_alarm) ? xadc_voltage_events : NULL, \
997	.num_event_specs = (_alarm) ? ARRAY_SIZE(xadc_voltage_events) : 0, \
998	.scan_index = (_scan_index), \
999	.scan_type = { \
1000		.sign = ((_addr) == XADC_REG_VREFN) ? 's' : 'u', \
1001		.realbits = 12, \
1002		.storagebits = 16, \
1003		.shift = 4, \
1004		.endianness = IIO_CPU, \
1005	}, \
1006	.extend_name = _ext, \
1007}
1008
1009static const struct iio_chan_spec xadc_channels[] = {
1010	XADC_CHAN_TEMP(0, 8, XADC_REG_TEMP),
1011	XADC_CHAN_VOLTAGE(0, 9, XADC_REG_VCCINT, "vccint", true),
1012	XADC_CHAN_VOLTAGE(1, 10, XADC_REG_VCCAUX, "vccaux", true),
1013	XADC_CHAN_VOLTAGE(2, 14, XADC_REG_VCCBRAM, "vccbram", true),
1014	XADC_CHAN_VOLTAGE(3, 5, XADC_REG_VCCPINT, "vccpint", true),
1015	XADC_CHAN_VOLTAGE(4, 6, XADC_REG_VCCPAUX, "vccpaux", true),
1016	XADC_CHAN_VOLTAGE(5, 7, XADC_REG_VCCO_DDR, "vccoddr", true),
1017	XADC_CHAN_VOLTAGE(6, 12, XADC_REG_VREFP, "vrefp", false),
1018	XADC_CHAN_VOLTAGE(7, 13, XADC_REG_VREFN, "vrefn", false),
1019	XADC_CHAN_VOLTAGE(8, 11, XADC_REG_VPVN, NULL, false),
1020	XADC_CHAN_VOLTAGE(9, 16, XADC_REG_VAUX(0), NULL, false),
1021	XADC_CHAN_VOLTAGE(10, 17, XADC_REG_VAUX(1), NULL, false),
1022	XADC_CHAN_VOLTAGE(11, 18, XADC_REG_VAUX(2), NULL, false),
1023	XADC_CHAN_VOLTAGE(12, 19, XADC_REG_VAUX(3), NULL, false),
1024	XADC_CHAN_VOLTAGE(13, 20, XADC_REG_VAUX(4), NULL, false),
1025	XADC_CHAN_VOLTAGE(14, 21, XADC_REG_VAUX(5), NULL, false),
1026	XADC_CHAN_VOLTAGE(15, 22, XADC_REG_VAUX(6), NULL, false),
1027	XADC_CHAN_VOLTAGE(16, 23, XADC_REG_VAUX(7), NULL, false),
1028	XADC_CHAN_VOLTAGE(17, 24, XADC_REG_VAUX(8), NULL, false),
1029	XADC_CHAN_VOLTAGE(18, 25, XADC_REG_VAUX(9), NULL, false),
1030	XADC_CHAN_VOLTAGE(19, 26, XADC_REG_VAUX(10), NULL, false),
1031	XADC_CHAN_VOLTAGE(20, 27, XADC_REG_VAUX(11), NULL, false),
1032	XADC_CHAN_VOLTAGE(21, 28, XADC_REG_VAUX(12), NULL, false),
1033	XADC_CHAN_VOLTAGE(22, 29, XADC_REG_VAUX(13), NULL, false),
1034	XADC_CHAN_VOLTAGE(23, 30, XADC_REG_VAUX(14), NULL, false),
1035	XADC_CHAN_VOLTAGE(24, 31, XADC_REG_VAUX(15), NULL, false),
1036};
1037
1038static const struct iio_info xadc_info = {
1039	.read_raw = &xadc_read_raw,
1040	.write_raw = &xadc_write_raw,
1041	.read_event_config = &xadc_read_event_config,
1042	.write_event_config = &xadc_write_event_config,
1043	.read_event_value = &xadc_read_event_value,
1044	.write_event_value = &xadc_write_event_value,
1045	.update_scan_mode = &xadc_update_scan_mode,
1046	.driver_module = THIS_MODULE,
1047};
1048
1049static const struct of_device_id xadc_of_match_table[] = {
1050	{ .compatible = "xlnx,zynq-xadc-1.00.a", (void *)&xadc_zynq_ops },
1051	{ .compatible = "xlnx,axi-xadc-1.00.a", (void *)&xadc_axi_ops },
1052	{ },
1053};
1054MODULE_DEVICE_TABLE(of, xadc_of_match_table);
1055
1056static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
1057	unsigned int *conf)
1058{
1059	struct xadc *xadc = iio_priv(indio_dev);
1060	struct iio_chan_spec *channels, *chan;
1061	struct device_node *chan_node, *child;
1062	unsigned int num_channels;
1063	const char *external_mux;
1064	u32 ext_mux_chan;
1065	int reg;
1066	int ret;
1067
1068	*conf = 0;
1069
1070	ret = of_property_read_string(np, "xlnx,external-mux", &external_mux);
1071	if (ret < 0 || strcasecmp(external_mux, "none") == 0)
1072		xadc->external_mux_mode = XADC_EXTERNAL_MUX_NONE;
1073	else if (strcasecmp(external_mux, "single") == 0)
1074		xadc->external_mux_mode = XADC_EXTERNAL_MUX_SINGLE;
1075	else if (strcasecmp(external_mux, "dual") == 0)
1076		xadc->external_mux_mode = XADC_EXTERNAL_MUX_DUAL;
1077	else
1078		return -EINVAL;
1079
1080	if (xadc->external_mux_mode != XADC_EXTERNAL_MUX_NONE) {
1081		ret = of_property_read_u32(np, "xlnx,external-mux-channel",
1082					&ext_mux_chan);
1083		if (ret < 0)
1084			return ret;
1085
1086		if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_SINGLE) {
1087			if (ext_mux_chan == 0)
1088				ext_mux_chan = XADC_REG_VPVN;
1089			else if (ext_mux_chan <= 16)
1090				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1091			else
1092				return -EINVAL;
1093		} else {
1094			if (ext_mux_chan > 0 && ext_mux_chan <= 8)
1095				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1096			else
1097				return -EINVAL;
1098		}
1099
1100		*conf |= XADC_CONF0_MUX | XADC_CONF0_CHAN(ext_mux_chan);
1101	}
1102
1103	channels = kmemdup(xadc_channels, sizeof(xadc_channels), GFP_KERNEL);
1104	if (!channels)
1105		return -ENOMEM;
1106
1107	num_channels = 9;
1108	chan = &channels[9];
1109
1110	chan_node = of_get_child_by_name(np, "xlnx,channels");
1111	if (chan_node) {
1112		for_each_child_of_node(chan_node, child) {
1113			if (num_channels >= ARRAY_SIZE(xadc_channels)) {
1114				of_node_put(child);
1115				break;
1116			}
1117
1118			ret = of_property_read_u32(child, "reg", &reg);
1119			if (ret || reg > 16)
1120				continue;
1121
1122			if (of_property_read_bool(child, "xlnx,bipolar"))
1123				chan->scan_type.sign = 's';
1124
1125			if (reg == 0) {
1126				chan->scan_index = 11;
1127				chan->address = XADC_REG_VPVN;
1128			} else {
1129				chan->scan_index = 15 + reg;
1130				chan->address = XADC_REG_VAUX(reg - 1);
1131			}
1132			num_channels++;
1133			chan++;
1134		}
1135	}
1136	of_node_put(chan_node);
1137
1138	indio_dev->num_channels = num_channels;
1139	indio_dev->channels = krealloc(channels, sizeof(*channels) *
1140					num_channels, GFP_KERNEL);
1141	/* If we can't resize the channels array, just use the original */
1142	if (!indio_dev->channels)
1143		indio_dev->channels = channels;
1144
1145	return 0;
1146}
1147
1148static int xadc_probe(struct platform_device *pdev)
1149{
1150	const struct of_device_id *id;
1151	struct iio_dev *indio_dev;
1152	unsigned int bipolar_mask;
1153	struct resource *mem;
1154	unsigned int conf0;
1155	struct xadc *xadc;
1156	int ret;
1157	int irq;
1158	int i;
1159
1160	if (!pdev->dev.of_node)
1161		return -ENODEV;
1162
1163	id = of_match_node(xadc_of_match_table, pdev->dev.of_node);
1164	if (!id)
1165		return -EINVAL;
1166
1167	irq = platform_get_irq(pdev, 0);
1168	if (irq <= 0)
1169		return -ENXIO;
1170
1171	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*xadc));
1172	if (!indio_dev)
1173		return -ENOMEM;
1174
1175	xadc = iio_priv(indio_dev);
1176	xadc->ops = id->data;
1177	init_completion(&xadc->completion);
1178	mutex_init(&xadc->mutex);
1179	spin_lock_init(&xadc->lock);
1180	INIT_DELAYED_WORK(&xadc->zynq_unmask_work, xadc_zynq_unmask_worker);
1181
1182	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1183	xadc->base = devm_ioremap_resource(&pdev->dev, mem);
1184	if (IS_ERR(xadc->base))
1185		return PTR_ERR(xadc->base);
1186
1187	indio_dev->dev.parent = &pdev->dev;
1188	indio_dev->dev.of_node = pdev->dev.of_node;
1189	indio_dev->name = "xadc";
1190	indio_dev->modes = INDIO_DIRECT_MODE;
1191	indio_dev->info = &xadc_info;
1192
1193	ret = xadc_parse_dt(indio_dev, pdev->dev.of_node, &conf0);
1194	if (ret)
1195		goto err_device_free;
1196
1197	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1198		ret = iio_triggered_buffer_setup(indio_dev,
1199			&iio_pollfunc_store_time, &xadc_trigger_handler,
1200			&xadc_buffer_ops);
1201		if (ret)
1202			goto err_device_free;
1203
1204		xadc->convst_trigger = xadc_alloc_trigger(indio_dev, "convst");
1205		if (IS_ERR(xadc->convst_trigger)) {
1206			ret = PTR_ERR(xadc->convst_trigger);
1207			goto err_triggered_buffer_cleanup;
1208		}
1209		xadc->samplerate_trigger = xadc_alloc_trigger(indio_dev,
1210			"samplerate");
1211		if (IS_ERR(xadc->samplerate_trigger)) {
1212			ret = PTR_ERR(xadc->samplerate_trigger);
1213			goto err_free_convst_trigger;
1214		}
1215	}
1216
1217	xadc->clk = devm_clk_get(&pdev->dev, NULL);
1218	if (IS_ERR(xadc->clk)) {
1219		ret = PTR_ERR(xadc->clk);
1220		goto err_free_samplerate_trigger;
1221	}
1222	clk_prepare_enable(xadc->clk);
1223
1224	ret = xadc->ops->setup(pdev, indio_dev, irq);
1225	if (ret)
1226		goto err_free_samplerate_trigger;
1227
1228	ret = request_threaded_irq(irq, xadc->ops->interrupt_handler,
1229				xadc->ops->threaded_interrupt_handler,
1230				0, dev_name(&pdev->dev), indio_dev);
1231	if (ret)
1232		goto err_clk_disable_unprepare;
1233
1234	for (i = 0; i < 16; i++)
1235		xadc_read_adc_reg(xadc, XADC_REG_THRESHOLD(i),
1236			&xadc->threshold[i]);
1237
1238	ret = xadc_write_adc_reg(xadc, XADC_REG_CONF0, conf0);
1239	if (ret)
1240		goto err_free_irq;
1241
1242	bipolar_mask = 0;
1243	for (i = 0; i < indio_dev->num_channels; i++) {
1244		if (indio_dev->channels[i].scan_type.sign == 's')
1245			bipolar_mask |= BIT(indio_dev->channels[i].scan_index);
1246	}
1247
1248	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(0), bipolar_mask);
1249	if (ret)
1250		goto err_free_irq;
1251	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(1),
1252		bipolar_mask >> 16);
1253	if (ret)
1254		goto err_free_irq;
1255
1256	/* Disable all alarms */
1257	xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_ALARM_MASK,
1258		XADC_CONF1_ALARM_MASK);
1259
1260	/* Set thresholds to min/max */
1261	for (i = 0; i < 16; i++) {
1262		/*
1263		 * Set max voltage threshold and both temperature thresholds to
1264		 * 0xffff, min voltage threshold to 0.
1265		 */
1266		if (i % 8 < 4 || i == 7)
1267			xadc->threshold[i] = 0xffff;
1268		else
1269			xadc->threshold[i] = 0;
1270		xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(i),
1271			xadc->threshold[i]);
1272	}
1273
1274	/* Go to non-buffered mode */
1275	xadc_postdisable(indio_dev);
1276
1277	ret = iio_device_register(indio_dev);
1278	if (ret)
1279		goto err_free_irq;
1280
1281	platform_set_drvdata(pdev, indio_dev);
1282
1283	return 0;
1284
1285err_free_irq:
1286	free_irq(irq, indio_dev);
1287err_free_samplerate_trigger:
1288	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1289		iio_trigger_free(xadc->samplerate_trigger);
1290err_free_convst_trigger:
1291	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1292		iio_trigger_free(xadc->convst_trigger);
1293err_triggered_buffer_cleanup:
1294	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1295		iio_triggered_buffer_cleanup(indio_dev);
1296err_clk_disable_unprepare:
1297	clk_disable_unprepare(xadc->clk);
1298err_device_free:
1299	kfree(indio_dev->channels);
1300
1301	return ret;
1302}
1303
1304static int xadc_remove(struct platform_device *pdev)
1305{
1306	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1307	struct xadc *xadc = iio_priv(indio_dev);
1308	int irq = platform_get_irq(pdev, 0);
1309
1310	iio_device_unregister(indio_dev);
1311	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1312		iio_trigger_free(xadc->samplerate_trigger);
1313		iio_trigger_free(xadc->convst_trigger);
1314		iio_triggered_buffer_cleanup(indio_dev);
1315	}
1316	free_irq(irq, indio_dev);
1317	clk_disable_unprepare(xadc->clk);
1318	cancel_delayed_work(&xadc->zynq_unmask_work);
1319	kfree(xadc->data);
1320	kfree(indio_dev->channels);
1321
1322	return 0;
1323}
1324
1325static struct platform_driver xadc_driver = {
1326	.probe = xadc_probe,
1327	.remove = xadc_remove,
1328	.driver = {
1329		.name = "xadc",
1330		.of_match_table = xadc_of_match_table,
1331	},
1332};
1333module_platform_driver(xadc_driver);
1334
1335MODULE_LICENSE("GPL v2");
1336MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1337MODULE_DESCRIPTION("Xilinx XADC IIO driver");
1338