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mm: use pgdat_end_pfn() to simplify the code in others
[deliverable/linux.git] / drivers / iio / adc / at91_adc.c
CommitLineData
0e589d5f
MR		 1/*
2 * Driver for the ADC present in the Atmel AT91 evaluation boards.
3 *
4 * Copyright 2011 Free Electrons
5 *
6 * Licensed under the GPLv2 or later.
7 */
8
9#include <linux/bitmap.h>
10#include <linux/bitops.h>
11#include <linux/clk.h>
12#include <linux/err.h>
13#include <linux/io.h>
c8b11de0 14#include <linux/input.h>
0e589d5f
MR		 15#include <linux/interrupt.h>
16#include <linux/jiffies.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
e364185f
MR		 19#include <linux/of.h>
20#include <linux/of_device.h>
0e589d5f
MR		 21#include <linux/platform_device.h>
22#include <linux/sched.h>
23#include <linux/slab.h>
24#include <linux/wait.h>
25
26#include <linux/platform_data/at91_adc.h>
27
28#include <linux/iio/iio.h>
29#include <linux/iio/buffer.h>
0e589d5f
MR		 30#include <linux/iio/trigger.h>
31#include <linux/iio/trigger_consumer.h>
90032e4e 32#include <linux/iio/triggered_buffer.h>
0e589d5f
MR		 33
34#include <mach/at91_adc.h>
35
36#define AT91_ADC_CHAN(st, ch) \
37 (st->registers->channel_base + (ch * 4))
38#define at91_adc_readl(st, reg) \
39 (readl_relaxed(st->reg_base + reg))
40#define at91_adc_writel(st, reg, val) \
41 (writel_relaxed(val, st->reg_base + reg))
42
c8b11de0
JW		 43#define DRIVER_NAME "at91_adc"
44#define MAX_POS_BITS 12
45
46#define TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */
47#define TOUCH_PEN_DETECT_DEBOUNCE_US 200
48
e1811f97 49struct at91_adc_caps {
c8b11de0
JW		 50 bool has_ts; /* Support touch screen */
51 bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */
52 /*
53 * Numbers of sampling data will be averaged. Can be 0~3.
54 * Hardware can average (2 ^ ts_filter_average) sample data.
55 */
56 u8 ts_filter_average;
57 /* Pen Detection input pull-up resistor, can be 0~3 */
58 u8 ts_pen_detect_sensitivity;
59
c4601666
JW		 60 /* startup time calculate function */
61 u32 (*calc_startup_ticks)(u8 startup_time, u32 adc_clk_khz);
62
2b6d598b 63 u8 num_channels;
e1811f97
JW		 64 struct at91_adc_reg_desc registers;
65};
66
c8b11de0
JW		 67enum atmel_adc_ts_type {
68 ATMEL_ADC_TOUCHSCREEN_NONE = 0,
69 ATMEL_ADC_TOUCHSCREEN_4WIRE = 4,
70 ATMEL_ADC_TOUCHSCREEN_5WIRE = 5,
71};
72
0e589d5f
MR		 73struct at91_adc_state {
74 struct clk *adc_clk;
75 u16 *buffer;
76 unsigned long channels_mask;
77 struct clk *clk;
78 bool done;
79 int irq;
0e589d5f
MR		 80 u16 last_value;
81 struct mutex lock;
82 u8 num_channels;
83 void __iomem *reg_base;
84 struct at91_adc_reg_desc *registers;
85 u8 startup_time;
beca9e76 86 u8 sample_hold_time;
e748783c 87 bool sleep_mode;
0e589d5f
MR		 88 struct iio_trigger **trig;
89 struct at91_adc_trigger *trigger_list;
90 u32 trigger_number;
91 bool use_external;
92 u32 vref_mv;
47be16b6
LD		 93 u32 res; /* resolution used for convertions */
94 bool low_res; /* the resolution corresponds to the lowest one */
0e589d5f 95 wait_queue_head_t wq_data_avail;
e1811f97 96 struct at91_adc_caps *caps;
c8b11de0
JW		 97
98 /*
99 * Following ADC channels are shared by touchscreen:
100 *
101 * CH0 -- Touch screen XP/UL
102 * CH1 -- Touch screen XM/UR
103 * CH2 -- Touch screen YP/LL
104 * CH3 -- Touch screen YM/Sense
105 * CH4 -- Touch screen LR(5-wire only)
106 *
107 * The bitfields below represents the reserved channel in the
108 * touchscreen mode.
109 */
110#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0)
111#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0)
112 enum atmel_adc_ts_type touchscreen_type;
113 struct input_dev *ts_input;
114
115 u16 ts_sample_period_val;
116 u32 ts_pressure_threshold;
0e589d5f
MR		 117};
118
119static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
120{
121 struct iio_poll_func *pf = p;
122 struct iio_dev *idev = pf->indio_dev;
123 struct at91_adc_state *st = iio_priv(idev);
0e589d5f
MR		 124 int i, j = 0;
125
126 for (i = 0; i < idev->masklength; i++) {
127 if (!test_bit(i, idev->active_scan_mask))
128 continue;
129 st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, i));
130 j++;
131 }
132
e79cece0 133 iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
0e589d5f
MR		 134
135 iio_trigger_notify_done(idev->trig);
0e589d5f
MR		 136
137 /* Needed to ACK the DRDY interruption */
138 at91_adc_readl(st, AT91_ADC_LCDR);
139
140 enable_irq(st->irq);
141
142 return IRQ_HANDLED;
143}
144
c8b11de0
JW		 145/* Handler for classic adc channel eoc trigger */
146void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
0e589d5f 147{
0e589d5f 148 struct at91_adc_state *st = iio_priv(idev);
0e589d5f
MR		 149
150 if (iio_buffer_enabled(idev)) {
151 disable_irq_nosync(irq);
0e589d5f
MR		 152 iio_trigger_poll(idev->trig, iio_get_time_ns());
153 } else {
154 st->last_value = at91_adc_readl(st, AT91_ADC_LCDR);
155 st->done = true;
156 wake_up_interruptible(&st->wq_data_avail);
157 }
c8b11de0
JW		 158}
159
160static int at91_ts_sample(struct at91_adc_state *st)
161{
162 unsigned int xscale, yscale, reg, z1, z2;
163 unsigned int x, y, pres, xpos, ypos;
164 unsigned int rxp = 1;
165 unsigned int factor = 1000;
166 struct iio_dev *idev = iio_priv_to_dev(st);
167
168 unsigned int xyz_mask_bits = st->res;
169 unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
170
171 /* calculate position */
172 /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
173 reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
174 xpos = reg & xyz_mask;
175 x = (xpos << MAX_POS_BITS) - xpos;
176 xscale = (reg >> 16) & xyz_mask;
177 if (xscale == 0) {
178 dev_err(&idev->dev, "Error: xscale == 0!\n");
179 return -1;
180 }
181 x /= xscale;
182
183 /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
184 reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
185 ypos = reg & xyz_mask;
186 y = (ypos << MAX_POS_BITS) - ypos;
187 yscale = (reg >> 16) & xyz_mask;
188 if (yscale == 0) {
189 dev_err(&idev->dev, "Error: yscale == 0!\n");
190 return -1;
191 }
192 y /= yscale;
193
194 /* calculate the pressure */
195 reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
196 z1 = reg & xyz_mask;
197 z2 = (reg >> 16) & xyz_mask;
198
199 if (z1 != 0)
200 pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
201 / factor;
202 else
203 pres = st->ts_pressure_threshold; /* no pen contacted */
204
205 dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
206 xpos, xscale, ypos, yscale, z1, z2, pres);
207
208 if (pres < st->ts_pressure_threshold) {
209 dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
210 x, y, pres / factor);
211 input_report_abs(st->ts_input, ABS_X, x);
212 input_report_abs(st->ts_input, ABS_Y, y);
213 input_report_abs(st->ts_input, ABS_PRESSURE, pres);
214 input_report_key(st->ts_input, BTN_TOUCH, 1);
215 input_sync(st->ts_input);
216 } else {
217 dev_dbg(&idev->dev, "pressure too low: not reporting\n");
218 }
219
220 return 0;
221}
222
223static irqreturn_t at91_adc_interrupt(int irq, void *private)
224{
225 struct iio_dev *idev = private;
226 struct at91_adc_state *st = iio_priv(idev);
227 u32 status = at91_adc_readl(st, st->registers->status_register);
228 const uint32_t ts_data_irq_mask =
229 AT91_ADC_IER_XRDY |
230 AT91_ADC_IER_YRDY |
231 AT91_ADC_IER_PRDY;
232
233 if (status & st->registers->drdy_mask)
234 handle_adc_eoc_trigger(irq, idev);
235
236 if (status & AT91_ADC_IER_PEN) {
237 at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
238 at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
239 ts_data_irq_mask);
240 /* Set up period trigger for sampling */
241 at91_adc_writel(st, st->registers->trigger_register,
242 AT91_ADC_TRGR_MOD_PERIOD_TRIG |
243 AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
244 } else if (status & AT91_ADC_IER_NOPEN) {
245 at91_adc_writel(st, st->registers->trigger_register, 0);
246 at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
247 ts_data_irq_mask);
248 at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
249
250 input_report_key(st->ts_input, BTN_TOUCH, 0);
251 input_sync(st->ts_input);
252 } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
253 /* Now all touchscreen data is ready */
254
255 if (status & AT91_ADC_ISR_PENS) {
256 /* validate data by pen contact */
257 at91_ts_sample(st);
258 } else {
259 /* triggered by event that is no pen contact, just read
260 * them to clean the interrupt and discard all.
261 */
262 at91_adc_readl(st, AT91_ADC_TSXPOSR);
263 at91_adc_readl(st, AT91_ADC_TSYPOSR);
264 at91_adc_readl(st, AT91_ADC_TSPRESSR);
265 }
266 }
0e589d5f
MR		 267
268 return IRQ_HANDLED;
269}
270
271static int at91_adc_channel_init(struct iio_dev *idev)
272{
273 struct at91_adc_state *st = iio_priv(idev);
274 struct iio_chan_spec *chan_array, *timestamp;
275 int bit, idx = 0;
c8b11de0
JW		 276 unsigned long rsvd_mask = 0;
277
278 /* If touchscreen is enable, then reserve the adc channels */
279 if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
280 rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
281 else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
282 rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
283
284 /* set up the channel mask to reserve touchscreen channels */
285 st->channels_mask &= ~rsvd_mask;
0e589d5f
MR		 286
287 idev->num_channels = bitmap_weight(&st->channels_mask,
288 st->num_channels) + 1;
289
6b3aa313
AL		 290 chan_array = devm_kzalloc(&idev->dev,
291 ((idev->num_channels + 1) *
292 sizeof(struct iio_chan_spec)),
293 GFP_KERNEL);
0e589d5f
MR		 294
295 if (!chan_array)
296 return -ENOMEM;
297
298 for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
299 struct iio_chan_spec *chan = chan_array + idx;
300
301 chan->type = IIO_VOLTAGE;
302 chan->indexed = 1;
303 chan->channel = bit;
304 chan->scan_index = idx;
305 chan->scan_type.sign = 'u';
47be16b6 306 chan->scan_type.realbits = st->res;
0e589d5f 307 chan->scan_type.storagebits = 16;
01bdab66
JC		 308 chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
309 chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
0e589d5f
MR		 310 idx++;
311 }
312 timestamp = chan_array + idx;
313
314 timestamp->type = IIO_TIMESTAMP;
315 timestamp->channel = -1;
316 timestamp->scan_index = idx;
317 timestamp->scan_type.sign = 's';
318 timestamp->scan_type.realbits = 64;
319 timestamp->scan_type.storagebits = 64;
320
321 idev->channels = chan_array;
322 return idev->num_channels;
323}
324
325static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
326 struct at91_adc_trigger *triggers,
327 const char *trigger_name)
328{
329 struct at91_adc_state *st = iio_priv(idev);
330 u8 value = 0;
331 int i;
332
333 for (i = 0; i < st->trigger_number; i++) {
334 char *name = kasprintf(GFP_KERNEL,
335 "%s-dev%d-%s",
336 idev->name,
337 idev->id,
338 triggers[i].name);
339 if (!name)
340 return -ENOMEM;
341
342 if (strcmp(trigger_name, name) == 0) {
343 value = triggers[i].value;
344 kfree(name);
345 break;
346 }
347
348 kfree(name);
349 }
350
351 return value;
352}
353
354static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
355{
1e9663c6 356 struct iio_dev *idev = iio_trigger_get_drvdata(trig);
0e589d5f
MR		 357 struct at91_adc_state *st = iio_priv(idev);
358 struct iio_buffer *buffer = idev->buffer;
359 struct at91_adc_reg_desc *reg = st->registers;
360 u32 status = at91_adc_readl(st, reg->trigger_register);
361 u8 value;
362 u8 bit;
363
364 value = at91_adc_get_trigger_value_by_name(idev,
365 st->trigger_list,
366 idev->trig->name);
367 if (value == 0)
368 return -EINVAL;
369
370 if (state) {
371 st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
372 if (st->buffer == NULL)
373 return -ENOMEM;
374
375 at91_adc_writel(st, reg->trigger_register,
376 status | value);
377
378 for_each_set_bit(bit, buffer->scan_mask,
379 st->num_channels) {
380 struct iio_chan_spec const *chan = idev->channels + bit;
381 at91_adc_writel(st, AT91_ADC_CHER,
382 AT91_ADC_CH(chan->channel));
383 }
384
385 at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
386
387 } else {
388 at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
389
390 at91_adc_writel(st, reg->trigger_register,
391 status & ~value);
392
393 for_each_set_bit(bit, buffer->scan_mask,
394 st->num_channels) {
395 struct iio_chan_spec const *chan = idev->channels + bit;
396 at91_adc_writel(st, AT91_ADC_CHDR,
397 AT91_ADC_CH(chan->channel));
398 }
399 kfree(st->buffer);
400 }
401
402 return 0;
403}
404
405static const struct iio_trigger_ops at91_adc_trigger_ops = {
406 .owner = THIS_MODULE,
407 .set_trigger_state = &at91_adc_configure_trigger,
408};
409
410static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
411 struct at91_adc_trigger *trigger)
412{
413 struct iio_trigger *trig;
414 int ret;
415
416 trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
417 idev->id, trigger->name);
418 if (trig == NULL)
419 return NULL;
420
421 trig->dev.parent = idev->dev.parent;
1e9663c6 422 iio_trigger_set_drvdata(trig, idev);
0e589d5f
MR		 423 trig->ops = &at91_adc_trigger_ops;
424
425 ret = iio_trigger_register(trig);
426 if (ret)
427 return NULL;
428
429 return trig;
430}
431
432static int at91_adc_trigger_init(struct iio_dev *idev)
433{
434 struct at91_adc_state *st = iio_priv(idev);
435 int i, ret;
436
6b3aa313 437 st->trig = devm_kzalloc(&idev->dev,
42877236 438 st->trigger_number * sizeof(*st->trig),
6b3aa313 439 GFP_KERNEL);
0e589d5f
MR		 440
441 if (st->trig == NULL) {
442 ret = -ENOMEM;
443 goto error_ret;
444 }
445
446 for (i = 0; i < st->trigger_number; i++) {
447 if (st->trigger_list[i].is_external && !(st->use_external))
448 continue;
449
450 st->trig[i] = at91_adc_allocate_trigger(idev,
451 st->trigger_list + i);
452 if (st->trig[i] == NULL) {
453 dev_err(&idev->dev,
454 "Could not allocate trigger %d\n", i);
455 ret = -ENOMEM;
456 goto error_trigger;
457 }
458 }
459
460 return 0;
461
462error_trigger:
463 for (i--; i >= 0; i--) {
464 iio_trigger_unregister(st->trig[i]);
465 iio_trigger_free(st->trig[i]);
466 }
467error_ret:
468 return ret;
469}
470
471static void at91_adc_trigger_remove(struct iio_dev *idev)
472{
473 struct at91_adc_state *st = iio_priv(idev);
474 int i;
475
476 for (i = 0; i < st->trigger_number; i++) {
477 iio_trigger_unregister(st->trig[i]);
478 iio_trigger_free(st->trig[i]);
479 }
480}
481
0e589d5f
MR		 482static int at91_adc_buffer_init(struct iio_dev *idev)
483{
90032e4e
LPC		 484 return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
485 &at91_adc_trigger_handler, NULL);
0e589d5f
MR		 486}
487
488static void at91_adc_buffer_remove(struct iio_dev *idev)
489{
90032e4e 490 iio_triggered_buffer_cleanup(idev);
0e589d5f
MR		 491}
492
493static int at91_adc_read_raw(struct iio_dev *idev,
494 struct iio_chan_spec const *chan,
495 int *val, int *val2, long mask)
496{
497 struct at91_adc_state *st = iio_priv(idev);
498 int ret;
499
500 switch (mask) {
501 case IIO_CHAN_INFO_RAW:
502 mutex_lock(&st->lock);
503
504 at91_adc_writel(st, AT91_ADC_CHER,
505 AT91_ADC_CH(chan->channel));
506 at91_adc_writel(st, AT91_ADC_IER, st->registers->drdy_mask);
507 at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
508
509 ret = wait_event_interruptible_timeout(st->wq_data_avail,
510 st->done,
511 msecs_to_jiffies(1000));
512 if (ret == 0)
90e6dc7c
LPC		 513 ret = -ETIMEDOUT;
514 if (ret < 0) {
515 mutex_unlock(&st->lock);
0e589d5f 516 return ret;
90e6dc7c 517 }
0e589d5f
MR		 518
519 *val = st->last_value;
520
521 at91_adc_writel(st, AT91_ADC_CHDR,
522 AT91_ADC_CH(chan->channel));
523 at91_adc_writel(st, AT91_ADC_IDR, st->registers->drdy_mask);
524
525 st->last_value = 0;
526 st->done = false;
527 mutex_unlock(&st->lock);
528 return IIO_VAL_INT;
529
530 case IIO_CHAN_INFO_SCALE:
c45e561e
LPC		 531 *val = st->vref_mv;
532 *val2 = chan->scan_type.realbits;
533 return IIO_VAL_FRACTIONAL_LOG2;
0e589d5f
MR		 534 default:
535 break;
536 }
537 return -EINVAL;
538}
539
47be16b6
LD		 540static int at91_adc_of_get_resolution(struct at91_adc_state *st,
541 struct platform_device *pdev)
542{
543 struct iio_dev *idev = iio_priv_to_dev(st);
544 struct device_node *np = pdev->dev.of_node;
545 int count, i, ret = 0;
546 char *res_name, *s;
547 u32 *resolutions;
548
549 count = of_property_count_strings(np, "atmel,adc-res-names");
550 if (count < 2) {
551 dev_err(&idev->dev, "You must specified at least two resolution names for "
552 "adc-res-names property in the DT\n");
553 return count;
554 }
555
556 resolutions = kmalloc(count * sizeof(*resolutions), GFP_KERNEL);
557 if (!resolutions)
558 return -ENOMEM;
559
560 if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) {
561 dev_err(&idev->dev, "Missing adc-res property in the DT.\n");
562 ret = -ENODEV;
563 goto ret;
564 }
565
566 if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name))
567 res_name = "highres";
568
569 for (i = 0; i < count; i++) {
570 if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s))
571 continue;
572
573 if (strcmp(res_name, s))
574 continue;
575
576 st->res = resolutions[i];
577 if (!strcmp(res_name, "lowres"))
578 st->low_res = true;
579 else
580 st->low_res = false;
581
582 dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
583 goto ret;
584 }
585
586 dev_err(&idev->dev, "There is no resolution for %s\n", res_name);
587
588ret:
589 kfree(resolutions);
590 return ret;
591}
592
c4601666
JW		 593static u32 calc_startup_ticks_9260(u8 startup_time, u32 adc_clk_khz)
594{
595 /*
596 * Number of ticks needed to cover the startup time of the ADC
597 * as defined in the electrical characteristics of the board,
598 * divided by 8. The formula thus is :
599 * Startup Time = (ticks + 1) * 8 / ADC Clock
600 */
601 return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
602}
603
604static u32 calc_startup_ticks_9x5(u8 startup_time, u32 adc_clk_khz)
605{
606 /*
607 * For sama5d3x and at91sam9x5, the formula changes to:
608 * Startup Time = <lookup_table_value> / ADC Clock
609 */
610 const int startup_lookup[] = {
611 0 , 8 , 16 , 24 ,
612 64 , 80 , 96 , 112,
613 512, 576, 640, 704,
614 768, 832, 896, 960
615 };
616 int i, size = ARRAY_SIZE(startup_lookup);
617 unsigned int ticks;
618
619 ticks = startup_time * adc_clk_khz / 1000;
620 for (i = 0; i < size; i++)
621 if (ticks < startup_lookup[i])
622 break;
623
624 ticks = i;
625 if (ticks == size)
626 /* Reach the end of lookup table */
627 ticks = size - 1;
628
629 return ticks;
630}
631
e1811f97
JW		 632static const struct of_device_id at91_adc_dt_ids[];
633
c8b11de0
JW		 634static int at91_adc_probe_dt_ts(struct device_node *node,
635 struct at91_adc_state *st, struct device *dev)
636{
637 int ret;
638 u32 prop;
639
640 ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
641 if (ret) {
642 dev_info(dev, "ADC Touch screen is disabled.\n");
643 return 0;
644 }
645
646 switch (prop) {
647 case 4:
648 case 5:
649 st->touchscreen_type = prop;
650 break;
651 default:
652 dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
653 return -EINVAL;
654 }
655
656 prop = 0;
657 of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
658 st->ts_pressure_threshold = prop;
659 if (st->ts_pressure_threshold) {
660 return 0;
661 } else {
662 dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
663 return -EINVAL;
664 }
665}
666
e364185f
MR		 667static int at91_adc_probe_dt(struct at91_adc_state *st,
668 struct platform_device *pdev)
669{
670 struct iio_dev *idev = iio_priv_to_dev(st);
671 struct device_node *node = pdev->dev.of_node;
672 struct device_node *trig_node;
673 int i = 0, ret;
674 u32 prop;
675
676 if (!node)
677 return -EINVAL;
678
e1811f97
JW		 679 st->caps = (struct at91_adc_caps *)
680 of_match_device(at91_adc_dt_ids, &pdev->dev)->data;
681
e364185f
MR		 682 st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
683
684 if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
685 dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
686 ret = -EINVAL;
687 goto error_ret;
688 }
689 st->channels_mask = prop;
690
e748783c
JCPV		 691 st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
692
e364185f
MR		 693 if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
694 dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
695 ret = -EINVAL;
696 goto error_ret;
697 }
698 st->startup_time = prop;
699
beca9e76
JCPV		 700 prop = 0;
701 of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
702 st->sample_hold_time = prop;
e364185f
MR		 703
704 if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
705 dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
706 ret = -EINVAL;
707 goto error_ret;
708 }
709 st->vref_mv = prop;
710
47be16b6
LD		 711 ret = at91_adc_of_get_resolution(st, pdev);
712 if (ret)
713 goto error_ret;
714
e1811f97 715 st->registers = &st->caps->registers;
2b6d598b 716 st->num_channels = st->caps->num_channels;
e364185f 717 st->trigger_number = of_get_child_count(node);
6b3aa313
AL		 718 st->trigger_list = devm_kzalloc(&idev->dev, st->trigger_number *
719 sizeof(struct at91_adc_trigger),
720 GFP_KERNEL);
e364185f
MR		 721 if (!st->trigger_list) {
722 dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
723 ret = -ENOMEM;
724 goto error_ret;
725 }
726
727 for_each_child_of_node(node, trig_node) {
728 struct at91_adc_trigger *trig = st->trigger_list + i;
729 const char *name;
730
731 if (of_property_read_string(trig_node, "trigger-name", &name)) {
732 dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
733 ret = -EINVAL;
734 goto error_ret;
735 }
736 trig->name = name;
737
738 if (of_property_read_u32(trig_node, "trigger-value", &prop)) {
739 dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
740 ret = -EINVAL;
741 goto error_ret;
742 }
743 trig->value = prop;
744 trig->is_external = of_property_read_bool(trig_node, "trigger-external");
745 i++;
746 }
747
c8b11de0
JW		 748 /* Check if touchscreen is supported. */
749 if (st->caps->has_ts)
750 return at91_adc_probe_dt_ts(node, st, &idev->dev);
751 else
752 dev_info(&idev->dev, "not support touchscreen in the adc compatible string.\n");
753
e364185f
MR		 754 return 0;
755
756error_ret:
757 return ret;
758}
759
0e589d5f
MR		 760static int at91_adc_probe_pdata(struct at91_adc_state *st,
761 struct platform_device *pdev)
762{
763 struct at91_adc_data *pdata = pdev->dev.platform_data;
764
765 if (!pdata)
766 return -EINVAL;
767
768 st->use_external = pdata->use_external_triggers;
769 st->vref_mv = pdata->vref;
770 st->channels_mask = pdata->channels_used;
771 st->num_channels = pdata->num_channels;
772 st->startup_time = pdata->startup_time;
773 st->trigger_number = pdata->trigger_number;
774 st->trigger_list = pdata->trigger_list;
775 st->registers = pdata->registers;
776
777 return 0;
778}
779
780static const struct iio_info at91_adc_info = {
781 .driver_module = THIS_MODULE,
782 .read_raw = &at91_adc_read_raw,
783};
784
c8b11de0
JW		 785/* Touchscreen related functions */
786static int atmel_ts_open(struct input_dev *dev)
787{
788 struct at91_adc_state *st = input_get_drvdata(dev);
789
790 at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
791 return 0;
792}
793
794static void atmel_ts_close(struct input_dev *dev)
795{
796 struct at91_adc_state *st = input_get_drvdata(dev);
797
798 at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
799}
800
801static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
802{
803 u32 reg = 0, pendbc;
804 int i = 0;
805
806 if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
807 reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
808 else
809 reg = AT91_ADC_TSMR_TSMODE_5WIRE;
810
811 /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
812 * pen detect noise.
813 * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
814 */
815 pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz / 1000, 1);
816
817 while (pendbc >> ++i)
818 ; /* Empty! Find the shift offset */
819 if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1))))
820 pendbc = i;
821 else
822 pendbc = i - 1;
823
824 if (st->caps->has_tsmr) {
825 reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
826 & AT91_ADC_TSMR_TSAV;
827 reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC;
828 reg |= AT91_ADC_TSMR_NOTSDMA;
829 reg |= AT91_ADC_TSMR_PENDET_ENA;
830 reg |= 0x03 << 8; /* TSFREQ, need bigger than TSAV */
831
832 at91_adc_writel(st, AT91_ADC_TSMR, reg);
833 } else {
834 /* TODO: for 9g45 which has no TSMR */
835 }
836
837 /* Change adc internal resistor value for better pen detection,
838 * default value is 100 kOhm.
839 * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
840 * option only available on ES2 and higher
841 */
842 at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
843 & AT91_ADC_ACR_PENDETSENS);
844
845 /* Sample Peroid Time = (TRGPER + 1) / ADCClock */
846 st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
847 adc_clk_khz / 1000) - 1, 1);
848
849 return 0;
850}
851
852static int at91_ts_register(struct at91_adc_state *st,
853 struct platform_device *pdev)
854{
855 struct input_dev *input;
856 struct iio_dev *idev = iio_priv_to_dev(st);
857 int ret;
858
859 input = input_allocate_device();
860 if (!input) {
861 dev_err(&idev->dev, "Failed to allocate TS device!\n");
862 return -ENOMEM;
863 }
864
865 input->name = DRIVER_NAME;
866 input->id.bustype = BUS_HOST;
867 input->dev.parent = &pdev->dev;
868 input->open = atmel_ts_open;
869 input->close = atmel_ts_close;
870
871 __set_bit(EV_ABS, input->evbit);
872 __set_bit(EV_KEY, input->evbit);
873 __set_bit(BTN_TOUCH, input->keybit);
874 input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1, 0, 0);
875 input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0);
876 input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
877
878 st->ts_input = input;
879 input_set_drvdata(input, st);
880
881 ret = input_register_device(input);
882 if (ret)
883 input_free_device(st->ts_input);
884
885 return ret;
886}
887
888static void at91_ts_unregister(struct at91_adc_state *st)
889{
890 input_unregister_device(st->ts_input);
891}
892
fc52692c 893static int at91_adc_probe(struct platform_device *pdev)
0e589d5f 894{
db10e201 895 unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
0e589d5f
MR		 896 int ret;
897 struct iio_dev *idev;
898 struct at91_adc_state *st;
899 struct resource *res;
e748783c 900 u32 reg;
0e589d5f 901
f8837532
SK		 902 idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
903 if (!idev)
904 return -ENOMEM;
0e589d5f
MR		 905
906 st = iio_priv(idev);
907
e364185f
MR		 908 if (pdev->dev.of_node)
909 ret = at91_adc_probe_dt(st, pdev);
910 else
911 ret = at91_adc_probe_pdata(st, pdev);
912
0e589d5f
MR		 913 if (ret) {
914 dev_err(&pdev->dev, "No platform data available.\n");
f8837532 915 return -EINVAL;
0e589d5f
MR		 916 }
917
0e589d5f
MR		 918 platform_set_drvdata(pdev, idev);
919
920 idev->dev.parent = &pdev->dev;
921 idev->name = dev_name(&pdev->dev);
922 idev->modes = INDIO_DIRECT_MODE;
923 idev->info = &at91_adc_info;
924
925 st->irq = platform_get_irq(pdev, 0);
926 if (st->irq < 0) {
927 dev_err(&pdev->dev, "No IRQ ID is designated\n");
f8837532 928 return -ENODEV;
0e589d5f
MR		 929 }
930
390d75c1 931 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0e589d5f 932
5fd98466
TR		 933 st->reg_base = devm_ioremap_resource(&pdev->dev, res);
934 if (IS_ERR(st->reg_base)) {
f8837532 935 return PTR_ERR(st->reg_base);
0e589d5f
MR		 936 }
937
938 /*
939 * Disable all IRQs before setting up the handler
940 */
941 at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
942 at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
943 ret = request_irq(st->irq,
c8b11de0 944 at91_adc_interrupt,
0e589d5f
MR		 945 0,
946 pdev->dev.driver->name,
947 idev);
948 if (ret) {
949 dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
f8837532 950 return ret;
0e589d5f
MR		 951 }
952
390d75c1 953 st->clk = devm_clk_get(&pdev->dev, "adc_clk");
0e589d5f
MR		 954 if (IS_ERR(st->clk)) {
955 dev_err(&pdev->dev, "Failed to get the clock.\n");
956 ret = PTR_ERR(st->clk);
957 goto error_free_irq;
958 }
959
00062a9c 960 ret = clk_prepare_enable(st->clk);
0e589d5f 961 if (ret) {
00062a9c
JL		 962 dev_err(&pdev->dev,
963 "Could not prepare or enable the clock.\n");
390d75c1 964 goto error_free_irq;
0e589d5f
MR		 965 }
966
390d75c1 967 st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
0e589d5f
MR		 968 if (IS_ERR(st->adc_clk)) {
969 dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
f755bbbf 970 ret = PTR_ERR(st->adc_clk);
0e589d5f
MR		 971 goto error_disable_clk;
972 }
973
00062a9c 974 ret = clk_prepare_enable(st->adc_clk);
0e589d5f 975 if (ret) {
00062a9c
JL		 976 dev_err(&pdev->dev,
977 "Could not prepare or enable the ADC clock.\n");
390d75c1 978 goto error_disable_clk;
0e589d5f
MR		 979 }
980
0e589d5f
MR		 981 /*
982 * Prescaler rate computation using the formula from the Atmel's
983 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
984 * specified by the electrical characteristics of the board.
985 */
986 mstrclk = clk_get_rate(st->clk);
987 adc_clk = clk_get_rate(st->adc_clk);
db10e201 988 adc_clk_khz = adc_clk / 1000;
c8b11de0
JW		 989
990 dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
991 mstrclk, adc_clk);
992
0e589d5f
MR		 993 prsc = (mstrclk / (2 * adc_clk)) - 1;
994
995 if (!st->startup_time) {
996 dev_err(&pdev->dev, "No startup time available.\n");
997 ret = -EINVAL;
998 goto error_disable_adc_clk;
999 }
c4601666 1000 ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
0e589d5f 1001
beca9e76
JCPV		 1002 /*
1003 * a minimal Sample and Hold Time is necessary for the ADC to guarantee
1004 * the best converted final value between two channels selection
1005 * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
1006 */
db10e201
JW		 1007 shtim = round_up((st->sample_hold_time * adc_clk_khz /
1008 1000) - 1, 1);
beca9e76 1009
9120c0be
JW		 1010 reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
1011 reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
47be16b6 1012 if (st->low_res)
e748783c
JCPV		 1013 reg |= AT91_ADC_LOWRES;
1014 if (st->sleep_mode)
1015 reg |= AT91_ADC_SLEEP;
beca9e76 1016 reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
e748783c 1017 at91_adc_writel(st, AT91_ADC_MR, reg);
0e589d5f
MR		 1018
1019 /* Setup the ADC channels available on the board */
1020 ret = at91_adc_channel_init(idev);
1021 if (ret < 0) {
1022 dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
1023 goto error_disable_adc_clk;
1024 }
1025
1026 init_waitqueue_head(&st->wq_data_avail);
1027 mutex_init(&st->lock);
1028
c8b11de0
JW		 1029 /*
1030 * Since touch screen will set trigger register as period trigger. So
1031 * when touch screen is enabled, then we have to disable hardware
1032 * trigger for classic adc.
1033 */
1034 if (!st->touchscreen_type) {
1035 ret = at91_adc_buffer_init(idev);
1036 if (ret < 0) {
1037 dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
1038 goto error_disable_adc_clk;
1039 }
0e589d5f 1040
c8b11de0
JW		 1041 ret = at91_adc_trigger_init(idev);
1042 if (ret < 0) {
1043 dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
1044 at91_adc_buffer_remove(idev);
1045 goto error_disable_adc_clk;
1046 }
1047 } else {
1048 if (!st->caps->has_tsmr) {
1049 dev_err(&pdev->dev, "We don't support non-TSMR adc\n");
1050 goto error_disable_adc_clk;
1051 }
1052
1053 ret = at91_ts_register(st, pdev);
1054 if (ret)
1055 goto error_disable_adc_clk;
1056
1057 at91_ts_hw_init(st, adc_clk_khz);
0e589d5f
MR		 1058 }
1059
1060 ret = iio_device_register(idev);
1061 if (ret < 0) {
1062 dev_err(&pdev->dev, "Couldn't register the device.\n");
c8b11de0 1063 goto error_iio_device_register;
0e589d5f
MR		 1064 }
1065
1066 return 0;
1067
c8b11de0
JW		 1068error_iio_device_register:
1069 if (!st->touchscreen_type) {
1070 at91_adc_trigger_remove(idev);
1071 at91_adc_buffer_remove(idev);
1072 } else {
1073 at91_ts_unregister(st);
1074 }
0e589d5f 1075error_disable_adc_clk:
00062a9c 1076 clk_disable_unprepare(st->adc_clk);
0e589d5f 1077error_disable_clk:
00062a9c 1078 clk_disable_unprepare(st->clk);
0e589d5f
MR		 1079error_free_irq:
1080 free_irq(st->irq, idev);
0e589d5f
MR		 1081 return ret;
1082}
1083
fc52692c 1084static int at91_adc_remove(struct platform_device *pdev)
0e589d5f
MR		 1085{
1086 struct iio_dev *idev = platform_get_drvdata(pdev);
0e589d5f
MR		 1087 struct at91_adc_state *st = iio_priv(idev);
1088
1089 iio_device_unregister(idev);
c8b11de0
JW		 1090 if (!st->touchscreen_type) {
1091 at91_adc_trigger_remove(idev);
1092 at91_adc_buffer_remove(idev);
1093 } else {
1094 at91_ts_unregister(st);
1095 }
0e589d5f 1096 clk_disable_unprepare(st->adc_clk);
00062a9c 1097 clk_disable_unprepare(st->clk);
0e589d5f 1098 free_irq(st->irq, idev);
0e589d5f
MR		 1099
1100 return 0;
1101}
1102
00738ff6 1103#ifdef CONFIG_OF
e1811f97 1104static struct at91_adc_caps at91sam9260_caps = {
c4601666 1105 .calc_startup_ticks = calc_startup_ticks_9260,
2b6d598b 1106 .num_channels = 4,
e1811f97
JW		 1107 .registers = {
1108 .channel_base = AT91_ADC_CHR(0),
1109 .drdy_mask = AT91_ADC_DRDY,
1110 .status_register = AT91_ADC_SR,
1111 .trigger_register = AT91_ADC_TRGR_9260,
9120c0be
JW		 1112 .mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1113 .mr_startup_mask = AT91_ADC_STARTUP_9260,
e1811f97
JW		 1114 },
1115};
1116
1117static struct at91_adc_caps at91sam9g45_caps = {
c8b11de0 1118 .has_ts = true,
c4601666 1119 .calc_startup_ticks = calc_startup_ticks_9260, /* same as 9260 */
2b6d598b 1120 .num_channels = 8,
e1811f97
JW		 1121 .registers = {
1122 .channel_base = AT91_ADC_CHR(0),
1123 .drdy_mask = AT91_ADC_DRDY,
1124 .status_register = AT91_ADC_SR,
1125 .trigger_register = AT91_ADC_TRGR_9G45,
9120c0be
JW		 1126 .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1127 .mr_startup_mask = AT91_ADC_STARTUP_9G45,
e1811f97
JW		 1128 },
1129};
1130
1131static struct at91_adc_caps at91sam9x5_caps = {
c8b11de0
JW		 1132 .has_ts = true,
1133 .has_tsmr = true,
1134 .ts_filter_average = 3,
1135 .ts_pen_detect_sensitivity = 2,
c4601666 1136 .calc_startup_ticks = calc_startup_ticks_9x5,
2b6d598b 1137 .num_channels = 12,
e1811f97
JW		 1138 .registers = {
1139 .channel_base = AT91_ADC_CDR0_9X5,
1140 .drdy_mask = AT91_ADC_SR_DRDY_9X5,
1141 .status_register = AT91_ADC_SR_9X5,
1142 .trigger_register = AT91_ADC_TRGR_9X5,
9120c0be
JW		 1143 /* prescal mask is same as 9G45 */
1144 .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1145 .mr_startup_mask = AT91_ADC_STARTUP_9X5,
e1811f97
JW		 1146 },
1147};
1148
e364185f 1149static const struct of_device_id at91_adc_dt_ids[] = {
e1811f97
JW		 1150 { .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
1151 { .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
1152 { .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
e364185f
MR		 1153 {},
1154};
1155MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
00738ff6 1156#endif
e364185f 1157
0e589d5f
MR		 1158static struct platform_driver at91_adc_driver = {
1159 .probe = at91_adc_probe,
fc52692c 1160 .remove = at91_adc_remove,
0e589d5f 1161 .driver = {
c8b11de0 1162 .name = DRIVER_NAME,
e364185f 1163 .of_match_table = of_match_ptr(at91_adc_dt_ids),
0e589d5f
MR		 1164 },
1165};
1166
1167module_platform_driver(at91_adc_driver);
1168
1169MODULE_LICENSE("GPL");
1170MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
1171MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
Linux kernel - Deliverables
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