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dm writecache: add cond_resched to loop in persistent_memory_claim()
[linux/fpc-iii.git] / drivers / iio / adc / at91-sama5d2_adc.c
blob9d96f7d08b9567f4ff4663020c4d224cea568756
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Atmel ADC driver for SAMA5D2 devices and compatible.
4 *
5 * Copyright (C) 2015 Atmel,
6 * 2015 Ludovic Desroches <ludovic.desroches@atmel.com>
7 */
8
9 #include <linux/bitops.h>
10 #include <linux/clk.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmaengine.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/platform_device.h>
18 #include <linux/sched.h>
19 #include <linux/wait.h>
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/trigger.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/iio/triggered_buffer.h>
26 #include <linux/pinctrl/consumer.h>
27 #include <linux/regulator/consumer.h>
28
29 /* Control Register */
30 #define AT91_SAMA5D2_CR 0x00
31 /* Software Reset */
32 #define AT91_SAMA5D2_CR_SWRST BIT(0)
33 /* Start Conversion */
34 #define AT91_SAMA5D2_CR_START BIT(1)
35 /* Touchscreen Calibration */
36 #define AT91_SAMA5D2_CR_TSCALIB BIT(2)
37 /* Comparison Restart */
38 #define AT91_SAMA5D2_CR_CMPRST BIT(4)
39
40 /* Mode Register */
41 #define AT91_SAMA5D2_MR 0x04
42 /* Trigger Selection */
43 #define AT91_SAMA5D2_MR_TRGSEL(v) ((v) << 1)
44 /* ADTRG */
45 #define AT91_SAMA5D2_MR_TRGSEL_TRIG0 0
46 /* TIOA0 */
47 #define AT91_SAMA5D2_MR_TRGSEL_TRIG1 1
48 /* TIOA1 */
49 #define AT91_SAMA5D2_MR_TRGSEL_TRIG2 2
50 /* TIOA2 */
51 #define AT91_SAMA5D2_MR_TRGSEL_TRIG3 3
52 /* PWM event line 0 */
53 #define AT91_SAMA5D2_MR_TRGSEL_TRIG4 4
54 /* PWM event line 1 */
55 #define AT91_SAMA5D2_MR_TRGSEL_TRIG5 5
56 /* TIOA3 */
57 #define AT91_SAMA5D2_MR_TRGSEL_TRIG6 6
58 /* RTCOUT0 */
59 #define AT91_SAMA5D2_MR_TRGSEL_TRIG7 7
60 /* Sleep Mode */
61 #define AT91_SAMA5D2_MR_SLEEP BIT(5)
62 /* Fast Wake Up */
63 #define AT91_SAMA5D2_MR_FWUP BIT(6)
64 /* Prescaler Rate Selection */
65 #define AT91_SAMA5D2_MR_PRESCAL(v) ((v) << AT91_SAMA5D2_MR_PRESCAL_OFFSET)
66 #define AT91_SAMA5D2_MR_PRESCAL_OFFSET 8
67 #define AT91_SAMA5D2_MR_PRESCAL_MAX 0xff
68 #define AT91_SAMA5D2_MR_PRESCAL_MASK GENMASK(15, 8)
69 /* Startup Time */
70 #define AT91_SAMA5D2_MR_STARTUP(v) ((v) << 16)
71 #define AT91_SAMA5D2_MR_STARTUP_MASK GENMASK(19, 16)
72 /* Analog Change */
73 #define AT91_SAMA5D2_MR_ANACH BIT(23)
74 /* Tracking Time */
75 #define AT91_SAMA5D2_MR_TRACKTIM(v) ((v) << 24)
76 #define AT91_SAMA5D2_MR_TRACKTIM_MAX 0xff
77 /* Transfer Time */
78 #define AT91_SAMA5D2_MR_TRANSFER(v) ((v) << 28)
79 #define AT91_SAMA5D2_MR_TRANSFER_MAX 0x3
80 /* Use Sequence Enable */
81 #define AT91_SAMA5D2_MR_USEQ BIT(31)
82
83 /* Channel Sequence Register 1 */
84 #define AT91_SAMA5D2_SEQR1 0x08
85 /* Channel Sequence Register 2 */
86 #define AT91_SAMA5D2_SEQR2 0x0c
87 /* Channel Enable Register */
88 #define AT91_SAMA5D2_CHER 0x10
89 /* Channel Disable Register */
90 #define AT91_SAMA5D2_CHDR 0x14
91 /* Channel Status Register */
92 #define AT91_SAMA5D2_CHSR 0x18
93 /* Last Converted Data Register */
94 #define AT91_SAMA5D2_LCDR 0x20
95 /* Interrupt Enable Register */
96 #define AT91_SAMA5D2_IER 0x24
97 /* Interrupt Enable Register - TS X measurement ready */
98 #define AT91_SAMA5D2_IER_XRDY BIT(20)
99 /* Interrupt Enable Register - TS Y measurement ready */
100 #define AT91_SAMA5D2_IER_YRDY BIT(21)
101 /* Interrupt Enable Register - TS pressure measurement ready */
102 #define AT91_SAMA5D2_IER_PRDY BIT(22)
103 /* Interrupt Enable Register - general overrun error */
104 #define AT91_SAMA5D2_IER_GOVRE BIT(25)
105 /* Interrupt Enable Register - Pen detect */
106 #define AT91_SAMA5D2_IER_PEN BIT(29)
107 /* Interrupt Enable Register - No pen detect */
108 #define AT91_SAMA5D2_IER_NOPEN BIT(30)
109 /* Interrupt Disable Register */
110 #define AT91_SAMA5D2_IDR 0x28
111 /* Interrupt Mask Register */
112 #define AT91_SAMA5D2_IMR 0x2c
113 /* Interrupt Status Register */
114 #define AT91_SAMA5D2_ISR 0x30
115 /* Interrupt Status Register - Pen touching sense status */
116 #define AT91_SAMA5D2_ISR_PENS BIT(31)
117 /* Last Channel Trigger Mode Register */
118 #define AT91_SAMA5D2_LCTMR 0x34
119 /* Last Channel Compare Window Register */
120 #define AT91_SAMA5D2_LCCWR 0x38
121 /* Overrun Status Register */
122 #define AT91_SAMA5D2_OVER 0x3c
123 /* Extended Mode Register */
124 #define AT91_SAMA5D2_EMR 0x40
125 /* Extended Mode Register - Oversampling rate */
126 #define AT91_SAMA5D2_EMR_OSR(V) ((V) << 16)
127 #define AT91_SAMA5D2_EMR_OSR_MASK GENMASK(17, 16)
128 #define AT91_SAMA5D2_EMR_OSR_1SAMPLES 0
129 #define AT91_SAMA5D2_EMR_OSR_4SAMPLES 1
130 #define AT91_SAMA5D2_EMR_OSR_16SAMPLES 2
131
132 /* Extended Mode Register - Averaging on single trigger event */
133 #define AT91_SAMA5D2_EMR_ASTE(V) ((V) << 20)
134 /* Compare Window Register */
135 #define AT91_SAMA5D2_CWR 0x44
136 /* Channel Gain Register */
137 #define AT91_SAMA5D2_CGR 0x48
138
139 /* Channel Offset Register */
140 #define AT91_SAMA5D2_COR 0x4c
141 #define AT91_SAMA5D2_COR_DIFF_OFFSET 16
142
143 /* Channel Data Register 0 */
144 #define AT91_SAMA5D2_CDR0 0x50
145 /* Analog Control Register */
146 #define AT91_SAMA5D2_ACR 0x94
147 /* Analog Control Register - Pen detect sensitivity mask */
148 #define AT91_SAMA5D2_ACR_PENDETSENS_MASK GENMASK(1, 0)
149
150 /* Touchscreen Mode Register */
151 #define AT91_SAMA5D2_TSMR 0xb0
152 /* Touchscreen Mode Register - No touch mode */
153 #define AT91_SAMA5D2_TSMR_TSMODE_NONE 0
154 /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
155 #define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_NO_PRESS 1
156 /* Touchscreen Mode Register - 4 wire screen, pressure measurement */
157 #define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS 2
158 /* Touchscreen Mode Register - 5 wire screen */
159 #define AT91_SAMA5D2_TSMR_TSMODE_5WIRE 3
160 /* Touchscreen Mode Register - Average samples mask */
161 #define AT91_SAMA5D2_TSMR_TSAV_MASK GENMASK(5, 4)
162 /* Touchscreen Mode Register - Average samples */
163 #define AT91_SAMA5D2_TSMR_TSAV(x) ((x) << 4)
164 /* Touchscreen Mode Register - Touch/trigger frequency ratio mask */
165 #define AT91_SAMA5D2_TSMR_TSFREQ_MASK GENMASK(11, 8)
166 /* Touchscreen Mode Register - Touch/trigger frequency ratio */
167 #define AT91_SAMA5D2_TSMR_TSFREQ(x) ((x) << 8)
168 /* Touchscreen Mode Register - Pen Debounce Time mask */
169 #define AT91_SAMA5D2_TSMR_PENDBC_MASK GENMASK(31, 28)
170 /* Touchscreen Mode Register - Pen Debounce Time */
171 #define AT91_SAMA5D2_TSMR_PENDBC(x) ((x) << 28)
172 /* Touchscreen Mode Register - No DMA for touch measurements */
173 #define AT91_SAMA5D2_TSMR_NOTSDMA BIT(22)
174 /* Touchscreen Mode Register - Disable pen detection */
175 #define AT91_SAMA5D2_TSMR_PENDET_DIS (0 << 24)
176 /* Touchscreen Mode Register - Enable pen detection */
177 #define AT91_SAMA5D2_TSMR_PENDET_ENA BIT(24)
178
179 /* Touchscreen X Position Register */
180 #define AT91_SAMA5D2_XPOSR 0xb4
181 /* Touchscreen Y Position Register */
182 #define AT91_SAMA5D2_YPOSR 0xb8
183 /* Touchscreen Pressure Register */
184 #define AT91_SAMA5D2_PRESSR 0xbc
185 /* Trigger Register */
186 #define AT91_SAMA5D2_TRGR 0xc0
187 /* Mask for TRGMOD field of TRGR register */
188 #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
189 /* No trigger, only software trigger can start conversions */
190 #define AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER 0
191 /* Trigger Mode external trigger rising edge */
192 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE 1
193 /* Trigger Mode external trigger falling edge */
194 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL 2
195 /* Trigger Mode external trigger any edge */
196 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY 3
197 /* Trigger Mode internal periodic */
198 #define AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC 5
199 /* Trigger Mode - trigger period mask */
200 #define AT91_SAMA5D2_TRGR_TRGPER_MASK GENMASK(31, 16)
201 /* Trigger Mode - trigger period */
202 #define AT91_SAMA5D2_TRGR_TRGPER(x) ((x) << 16)
203
204 /* Correction Select Register */
205 #define AT91_SAMA5D2_COSR 0xd0
206 /* Correction Value Register */
207 #define AT91_SAMA5D2_CVR 0xd4
208 /* Channel Error Correction Register */
209 #define AT91_SAMA5D2_CECR 0xd8
210 /* Write Protection Mode Register */
211 #define AT91_SAMA5D2_WPMR 0xe4
212 /* Write Protection Status Register */
213 #define AT91_SAMA5D2_WPSR 0xe8
214 /* Version Register */
215 #define AT91_SAMA5D2_VERSION 0xfc
216
217 #define AT91_SAMA5D2_HW_TRIG_CNT 3
218 #define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
219 #define AT91_SAMA5D2_DIFF_CHAN_CNT 6
220
221 #define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
222 AT91_SAMA5D2_DIFF_CHAN_CNT + 1)
223
224 #define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
225 AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
226 #define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
227 #define AT91_SAMA5D2_TOUCH_P_CHAN_IDX (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
228 #define AT91_SAMA5D2_MAX_CHAN_IDX AT91_SAMA5D2_TOUCH_P_CHAN_IDX
229
230 #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */
231 #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US 200
232
233 #define AT91_SAMA5D2_XYZ_MASK GENMASK(11, 0)
234
235 #define AT91_SAMA5D2_MAX_POS_BITS 12
236
237 /*
238 * Maximum number of bytes to hold conversion from all channels
239 * without the timestamp.
240 */
241 #define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
242 AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
243
244 /* This total must also include the timestamp */
245 #define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
246
247 #define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
248
249 #define AT91_HWFIFO_MAX_SIZE_STR "128"
250 #define AT91_HWFIFO_MAX_SIZE 128
251
252 /* Possible values for oversampling ratio */
253 #define AT91_OSR_1SAMPLES 1
254 #define AT91_OSR_4SAMPLES 4
255 #define AT91_OSR_16SAMPLES 16
256
257 #define AT91_SAMA5D2_CHAN_SINGLE(num, addr) \
258 { \
259 .type = IIO_VOLTAGE, \
260 .channel = num, \
261 .address = addr, \
262 .scan_index = num, \
263 .scan_type = { \
264 .sign = 'u', \
265 .realbits = 14, \
266 .storagebits = 16, \
267 }, \
268 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
269 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
270 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
271 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
272 .datasheet_name = "CH"#num, \
273 .indexed = 1, \
274 }
275
276 #define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr) \
277 { \
278 .type = IIO_VOLTAGE, \
279 .differential = 1, \
280 .channel = num, \
281 .channel2 = num2, \
282 .address = addr, \
283 .scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT, \
284 .scan_type = { \
285 .sign = 's', \
286 .realbits = 14, \
287 .storagebits = 16, \
288 }, \
289 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
290 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
291 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
292 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
293 .datasheet_name = "CH"#num"-CH"#num2, \
294 .indexed = 1, \
295 }
296
297 #define AT91_SAMA5D2_CHAN_TOUCH(num, name, mod) \
298 { \
299 .type = IIO_POSITIONRELATIVE, \
300 .modified = 1, \
301 .channel = num, \
302 .channel2 = mod, \
303 .scan_index = num, \
304 .scan_type = { \
305 .sign = 'u', \
306 .realbits = 12, \
307 .storagebits = 16, \
308 }, \
309 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
310 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
311 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
312 .datasheet_name = name, \
313 }
314 #define AT91_SAMA5D2_CHAN_PRESSURE(num, name) \
315 { \
316 .type = IIO_PRESSURE, \
317 .channel = num, \
318 .scan_index = num, \
319 .scan_type = { \
320 .sign = 'u', \
321 .realbits = 12, \
322 .storagebits = 16, \
323 }, \
324 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
325 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
326 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
327 .datasheet_name = name, \
328 }
329
330 #define at91_adc_readl(st, reg) readl_relaxed(st->base + reg)
331 #define at91_adc_writel(st, reg, val) writel_relaxed(val, st->base + reg)
332
333 struct at91_adc_soc_info {
334 unsigned startup_time;
335 unsigned min_sample_rate;
336 unsigned max_sample_rate;
337 };
338
339 struct at91_adc_trigger {
340 char *name;
341 unsigned int trgmod_value;
342 unsigned int edge_type;
343 bool hw_trig;
344 };
345
346 /**
347 * at91_adc_dma - at91-sama5d2 dma information struct
348 * @dma_chan: the dma channel acquired
349 * @rx_buf: dma coherent allocated area
350 * @rx_dma_buf: dma handler for the buffer
351 * @phys_addr: physical address of the ADC base register
352 * @buf_idx: index inside the dma buffer where reading was last done
353 * @rx_buf_sz: size of buffer used by DMA operation
354 * @watermark: number of conversions to copy before DMA triggers irq
355 * @dma_ts: hold the start timestamp of dma operation
356 */
357 struct at91_adc_dma {
358 struct dma_chan *dma_chan;
359 u8 *rx_buf;
360 dma_addr_t rx_dma_buf;
361 phys_addr_t phys_addr;
362 int buf_idx;
363 int rx_buf_sz;
364 int watermark;
365 s64 dma_ts;
366 };
367
368 /**
369 * at91_adc_touch - at91-sama5d2 touchscreen information struct
370 * @sample_period_val: the value for periodic trigger interval
371 * @touching: is the pen touching the screen or not
372 * @x_pos: temporary placeholder for pressure computation
373 * @channels_bitmask: bitmask with the touchscreen channels enabled
374 * @workq: workqueue for buffer data pushing
375 */
376 struct at91_adc_touch {
377 u16 sample_period_val;
378 bool touching;
379 u16 x_pos;
380 unsigned long channels_bitmask;
381 struct work_struct workq;
382 };
383
384 struct at91_adc_state {
385 void __iomem *base;
386 int irq;
387 struct clk *per_clk;
388 struct regulator *reg;
389 struct regulator *vref;
390 int vref_uv;
391 unsigned int current_sample_rate;
392 struct iio_trigger *trig;
393 const struct at91_adc_trigger *selected_trig;
394 const struct iio_chan_spec *chan;
395 bool conversion_done;
396 u32 conversion_value;
397 unsigned int oversampling_ratio;
398 struct at91_adc_soc_info soc_info;
399 wait_queue_head_t wq_data_available;
400 struct at91_adc_dma dma_st;
401 struct at91_adc_touch touch_st;
402 u16 buffer[AT91_BUFFER_MAX_HWORDS];
403 /*
404 * lock to prevent concurrent 'single conversion' requests through
405 * sysfs.
406 */
407 struct mutex lock;
408 };
409
410 static const struct at91_adc_trigger at91_adc_trigger_list[] = {
411 {
412 .name = "external_rising",
413 .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE,
414 .edge_type = IRQ_TYPE_EDGE_RISING,
415 .hw_trig = true,
416 },
417 {
418 .name = "external_falling",
419 .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL,
420 .edge_type = IRQ_TYPE_EDGE_FALLING,
421 .hw_trig = true,
422 },
423 {
424 .name = "external_any",
425 .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY,
426 .edge_type = IRQ_TYPE_EDGE_BOTH,
427 .hw_trig = true,
428 },
429 {
430 .name = "software",
431 .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER,
432 .edge_type = IRQ_TYPE_NONE,
433 .hw_trig = false,
434 },
435 };
436
437 static const struct iio_chan_spec at91_adc_channels[] = {
438 AT91_SAMA5D2_CHAN_SINGLE(0, 0x50),
439 AT91_SAMA5D2_CHAN_SINGLE(1, 0x54),
440 AT91_SAMA5D2_CHAN_SINGLE(2, 0x58),
441 AT91_SAMA5D2_CHAN_SINGLE(3, 0x5c),
442 AT91_SAMA5D2_CHAN_SINGLE(4, 0x60),
443 AT91_SAMA5D2_CHAN_SINGLE(5, 0x64),
444 AT91_SAMA5D2_CHAN_SINGLE(6, 0x68),
445 AT91_SAMA5D2_CHAN_SINGLE(7, 0x6c),
446 AT91_SAMA5D2_CHAN_SINGLE(8, 0x70),
447 AT91_SAMA5D2_CHAN_SINGLE(9, 0x74),
448 AT91_SAMA5D2_CHAN_SINGLE(10, 0x78),
449 AT91_SAMA5D2_CHAN_SINGLE(11, 0x7c),
450 AT91_SAMA5D2_CHAN_DIFF(0, 1, 0x50),
451 AT91_SAMA5D2_CHAN_DIFF(2, 3, 0x58),
452 AT91_SAMA5D2_CHAN_DIFF(4, 5, 0x60),
453 AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68),
454 AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70),
455 AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78),
456 IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_TIMESTAMP_CHAN_IDX),
457 AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_X_CHAN_IDX, "x", IIO_MOD_X),
458 AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, "y", IIO_MOD_Y),
459 AT91_SAMA5D2_CHAN_PRESSURE(AT91_SAMA5D2_TOUCH_P_CHAN_IDX, "pressure"),
460 };
461
462 static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
463 {
464 int i;
465
466 for (i = 0; i < indio_dev->num_channels; i++) {
467 if (indio_dev->channels[i].scan_index == chan)
468 return i;
469 }
470 return -EINVAL;
471 }
472
473 static inline struct iio_chan_spec const *
474 at91_adc_chan_get(struct iio_dev *indio_dev, int chan)
475 {
476 int index = at91_adc_chan_xlate(indio_dev, chan);
477
478 if (index < 0)
479 return NULL;
480 return indio_dev->channels + index;
481 }
482
483 static inline int at91_adc_of_xlate(struct iio_dev *indio_dev,
484 const struct of_phandle_args *iiospec)
485 {
486 return at91_adc_chan_xlate(indio_dev, iiospec->args[0]);
487 }
488
489 static void at91_adc_config_emr(struct at91_adc_state *st)
490 {
491 /* configure the extended mode register */
492 unsigned int emr = at91_adc_readl(st, AT91_SAMA5D2_EMR);
493
494 /* select oversampling per single trigger event */
495 emr |= AT91_SAMA5D2_EMR_ASTE(1);
496
497 /* delete leftover content if it's the case */
498 emr &= ~AT91_SAMA5D2_EMR_OSR_MASK;
499
500 /* select oversampling ratio from configuration */
501 switch (st->oversampling_ratio) {
502 case AT91_OSR_1SAMPLES:
503 emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES) &
504 AT91_SAMA5D2_EMR_OSR_MASK;
505 break;
506 case AT91_OSR_4SAMPLES:
507 emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES) &
508 AT91_SAMA5D2_EMR_OSR_MASK;
509 break;
510 case AT91_OSR_16SAMPLES:
511 emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES) &
512 AT91_SAMA5D2_EMR_OSR_MASK;
513 break;
514 }
515
516 at91_adc_writel(st, AT91_SAMA5D2_EMR, emr);
517 }
518
519 static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val)
520 {
521 if (st->oversampling_ratio == AT91_OSR_1SAMPLES) {
522 /*
523 * in this case we only have 12 bits of real data, but channel
524 * is registered as 14 bits, so shift left two bits
525 */
526 *val <<= 2;
527 } else if (st->oversampling_ratio == AT91_OSR_4SAMPLES) {
528 /*
529 * in this case we have 13 bits of real data, but channel
530 * is registered as 14 bits, so left shift one bit
531 */
532 *val <<= 1;
533 }
534
535 return IIO_VAL_INT;
536 }
537
538 static void at91_adc_adjust_val_osr_array(struct at91_adc_state *st, void *buf,
539 int len)
540 {
541 int i = 0, val;
542 u16 *buf_u16 = (u16 *) buf;
543
544 /*
545 * We are converting each two bytes (each sample).
546 * First convert the byte based array to u16, and convert each sample
547 * separately.
548 * Each value is two bytes in an array of chars, so to not shift
549 * more than we need, save the value separately.
550 * len is in bytes, so divide by two to get number of samples.
551 */
552 while (i < len / 2) {
553 val = buf_u16[i];
554 at91_adc_adjust_val_osr(st, &val);
555 buf_u16[i] = val;
556 i++;
557 }
558 }
559
560 static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
561 {
562 u32 clk_khz = st->current_sample_rate / 1000;
563 int i = 0;
564 u16 pendbc;
565 u32 tsmr, acr;
566
567 if (!state) {
568 /* disabling touch IRQs and setting mode to no touch enabled */
569 at91_adc_writel(st, AT91_SAMA5D2_IDR,
570 AT91_SAMA5D2_IER_PEN | AT91_SAMA5D2_IER_NOPEN);
571 at91_adc_writel(st, AT91_SAMA5D2_TSMR, 0);
572 return 0;
573 }
574 /*
575 * debounce time is in microseconds, we need it in milliseconds to
576 * multiply with kilohertz, so, divide by 1000, but after the multiply.
577 * round up to make sure pendbc is at least 1
578 */
579 pendbc = round_up(AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US *
580 clk_khz / 1000, 1);
581
582 /* get the required exponent */
583 while (pendbc >> i++)
584 ;
585
586 pendbc = i;
587
588 tsmr = AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS;
589
590 tsmr |= AT91_SAMA5D2_TSMR_TSAV(2) & AT91_SAMA5D2_TSMR_TSAV_MASK;
591 tsmr |= AT91_SAMA5D2_TSMR_PENDBC(pendbc) &
592 AT91_SAMA5D2_TSMR_PENDBC_MASK;
593 tsmr |= AT91_SAMA5D2_TSMR_NOTSDMA;
594 tsmr |= AT91_SAMA5D2_TSMR_PENDET_ENA;
595 tsmr |= AT91_SAMA5D2_TSMR_TSFREQ(2) & AT91_SAMA5D2_TSMR_TSFREQ_MASK;
596
597 at91_adc_writel(st, AT91_SAMA5D2_TSMR, tsmr);
598
599 acr = at91_adc_readl(st, AT91_SAMA5D2_ACR);
600 acr &= ~AT91_SAMA5D2_ACR_PENDETSENS_MASK;
601 acr |= 0x02 & AT91_SAMA5D2_ACR_PENDETSENS_MASK;
602 at91_adc_writel(st, AT91_SAMA5D2_ACR, acr);
603
604 /* Sample Period Time = (TRGPER + 1) / ADCClock */
605 st->touch_st.sample_period_val =
606 round_up((AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US *
607 clk_khz / 1000) - 1, 1);
608 /* enable pen detect IRQ */
609 at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN);
610
611 return 0;
612 }
613
614 static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
615 {
616 u32 val;
617 u32 scale, result, pos;
618
619 /*
620 * to obtain the actual position we must divide by scale
621 * and multiply with max, where
622 * max = 2^AT91_SAMA5D2_MAX_POS_BITS - 1
623 */
624 /* first half of register is the x or y, second half is the scale */
625 val = at91_adc_readl(st, reg);
626 if (!val)
627 dev_dbg(&iio_priv_to_dev(st)->dev, "pos is 0\n");
628
629 pos = val & AT91_SAMA5D2_XYZ_MASK;
630 result = (pos << AT91_SAMA5D2_MAX_POS_BITS) - pos;
631 scale = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
632 if (scale == 0) {
633 dev_err(&iio_priv_to_dev(st)->dev, "scale is 0\n");
634 return 0;
635 }
636 result /= scale;
637
638 return result;
639 }
640
641 static u16 at91_adc_touch_x_pos(struct at91_adc_state *st)
642 {
643 st->touch_st.x_pos = at91_adc_touch_pos(st, AT91_SAMA5D2_XPOSR);
644 return st->touch_st.x_pos;
645 }
646
647 static u16 at91_adc_touch_y_pos(struct at91_adc_state *st)
648 {
649 return at91_adc_touch_pos(st, AT91_SAMA5D2_YPOSR);
650 }
651
652 static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
653 {
654 u32 val;
655 u32 z1, z2;
656 u32 pres;
657 u32 rxp = 1;
658 u32 factor = 1000;
659
660 /* calculate the pressure */
661 val = at91_adc_readl(st, AT91_SAMA5D2_PRESSR);
662 z1 = val & AT91_SAMA5D2_XYZ_MASK;
663 z2 = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
664
665 if (z1 != 0)
666 pres = rxp * (st->touch_st.x_pos * factor / 1024) *
667 (z2 * factor / z1 - factor) /
668 factor;
669 else
670 pres = 0xFFFF; /* no pen contact */
671
672 /*
673 * The pressure from device grows down, minimum is 0xFFFF, maximum 0x0.
674 * We compute it this way, but let's return it in the expected way,
675 * growing from 0 to 0xFFFF.
676 */
677 return 0xFFFF - pres;
678 }
679
680 static int at91_adc_read_position(struct at91_adc_state *st, int chan, u16 *val)
681 {
682 *val = 0;
683 if (!st->touch_st.touching)
684 return -ENODATA;
685 if (chan == AT91_SAMA5D2_TOUCH_X_CHAN_IDX)
686 *val = at91_adc_touch_x_pos(st);
687 else if (chan == AT91_SAMA5D2_TOUCH_Y_CHAN_IDX)
688 *val = at91_adc_touch_y_pos(st);
689 else
690 return -ENODATA;
691
692 return IIO_VAL_INT;
693 }
694
695 static int at91_adc_read_pressure(struct at91_adc_state *st, int chan, u16 *val)
696 {
697 *val = 0;
698 if (!st->touch_st.touching)
699 return -ENODATA;
700 if (chan == AT91_SAMA5D2_TOUCH_P_CHAN_IDX)
701 *val = at91_adc_touch_pressure(st);
702 else
703 return -ENODATA;
704
705 return IIO_VAL_INT;
706 }
707
708 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
709 {
710 struct iio_dev *indio = iio_trigger_get_drvdata(trig);
711 struct at91_adc_state *st = iio_priv(indio);
712 u32 status = at91_adc_readl(st, AT91_SAMA5D2_TRGR);
713 u8 bit;
714
715 /* clear TRGMOD */
716 status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK;
717
718 if (state)
719 status |= st->selected_trig->trgmod_value;
720
721 /* set/unset hw trigger */
722 at91_adc_writel(st, AT91_SAMA5D2_TRGR, status);
723
724 for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) {
725 struct iio_chan_spec const *chan = at91_adc_chan_get(indio, bit);
726 u32 cor;
727
728 if (!chan)
729 continue;
730 /* these channel types cannot be handled by this trigger */
731 if (chan->type == IIO_POSITIONRELATIVE ||
732 chan->type == IIO_PRESSURE)
733 continue;
734
735 if (state) {
736 cor = at91_adc_readl(st, AT91_SAMA5D2_COR);
737
738 if (chan->differential)
739 cor |= (BIT(chan->channel) |
740 BIT(chan->channel2)) <<
741 AT91_SAMA5D2_COR_DIFF_OFFSET;
742 else
743 cor &= ~(BIT(chan->channel) <<
744 AT91_SAMA5D2_COR_DIFF_OFFSET);
745
746 at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
747 }
748
749 if (state) {
750 at91_adc_writel(st, AT91_SAMA5D2_CHER,
751 BIT(chan->channel));
752 /* enable irq only if not using DMA */
753 if (!st->dma_st.dma_chan) {
754 at91_adc_writel(st, AT91_SAMA5D2_IER,
755 BIT(chan->channel));
756 }
757 } else {
758 /* disable irq only if not using DMA */
759 if (!st->dma_st.dma_chan) {
760 at91_adc_writel(st, AT91_SAMA5D2_IDR,
761 BIT(chan->channel));
762 }
763 at91_adc_writel(st, AT91_SAMA5D2_CHDR,
764 BIT(chan->channel));
765 }
766 }
767
768 return 0;
769 }
770
771 static int at91_adc_reenable_trigger(struct iio_trigger *trig)
772 {
773 struct iio_dev *indio = iio_trigger_get_drvdata(trig);
774 struct at91_adc_state *st = iio_priv(indio);
775
776 /* if we are using DMA, we must not reenable irq after each trigger */
777 if (st->dma_st.dma_chan)
778 return 0;
779
780 enable_irq(st->irq);
781
782 /* Needed to ACK the DRDY interruption */
783 at91_adc_readl(st, AT91_SAMA5D2_LCDR);
784 return 0;
785 }
786
787 static const struct iio_trigger_ops at91_adc_trigger_ops = {
788 .set_trigger_state = &at91_adc_configure_trigger,
789 .try_reenable = &at91_adc_reenable_trigger,
790 .validate_device = iio_trigger_validate_own_device,
791 };
792
793 static int at91_adc_dma_size_done(struct at91_adc_state *st)
794 {
795 struct dma_tx_state state;
796 enum dma_status status;
797 int i, size;
798
799 status = dmaengine_tx_status(st->dma_st.dma_chan,
800 st->dma_st.dma_chan->cookie,
801 &state);
802 if (status != DMA_IN_PROGRESS)
803 return 0;
804
805 /* Transferred length is size in bytes from end of buffer */
806 i = st->dma_st.rx_buf_sz - state.residue;
807
808 /* Return available bytes */
809 if (i >= st->dma_st.buf_idx)
810 size = i - st->dma_st.buf_idx;
811 else
812 size = st->dma_st.rx_buf_sz + i - st->dma_st.buf_idx;
813 return size;
814 }
815
816 static void at91_dma_buffer_done(void *data)
817 {
818 struct iio_dev *indio_dev = data;
819
820 iio_trigger_poll_chained(indio_dev->trig);
821 }
822
823 static int at91_adc_dma_start(struct iio_dev *indio_dev)
824 {
825 struct at91_adc_state *st = iio_priv(indio_dev);
826 struct dma_async_tx_descriptor *desc;
827 dma_cookie_t cookie;
828 int ret;
829 u8 bit;
830
831 if (!st->dma_st.dma_chan)
832 return 0;
833
834 /* we start a new DMA, so set buffer index to start */
835 st->dma_st.buf_idx = 0;
836
837 /*
838 * compute buffer size w.r.t. watermark and enabled channels.
839 * scan_bytes is aligned so we need an exact size for DMA
840 */
841 st->dma_st.rx_buf_sz = 0;
842
843 for_each_set_bit(bit, indio_dev->active_scan_mask,
844 indio_dev->num_channels) {
845 struct iio_chan_spec const *chan =
846 at91_adc_chan_get(indio_dev, bit);
847
848 if (!chan)
849 continue;
850
851 st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8;
852 }
853 st->dma_st.rx_buf_sz *= st->dma_st.watermark;
854
855 /* Prepare a DMA cyclic transaction */
856 desc = dmaengine_prep_dma_cyclic(st->dma_st.dma_chan,
857 st->dma_st.rx_dma_buf,
858 st->dma_st.rx_buf_sz,
859 st->dma_st.rx_buf_sz / 2,
860 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
861
862 if (!desc) {
863 dev_err(&indio_dev->dev, "cannot prepare DMA cyclic\n");
864 return -EBUSY;
865 }
866
867 desc->callback = at91_dma_buffer_done;
868 desc->callback_param = indio_dev;
869
870 cookie = dmaengine_submit(desc);
871 ret = dma_submit_error(cookie);
872 if (ret) {
873 dev_err(&indio_dev->dev, "cannot submit DMA cyclic\n");
874 dmaengine_terminate_async(st->dma_st.dma_chan);
875 return ret;
876 }
877
878 /* enable general overrun error signaling */
879 at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_GOVRE);
880 /* Issue pending DMA requests */
881 dma_async_issue_pending(st->dma_st.dma_chan);
882
883 /* consider current time as DMA start time for timestamps */
884 st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
885
886 dev_dbg(&indio_dev->dev, "DMA cyclic started\n");
887
888 return 0;
889 }
890
891 static int at91_adc_buffer_postenable(struct iio_dev *indio_dev)
892 {
893 int ret;
894 struct at91_adc_state *st = iio_priv(indio_dev);
895
896 /* check if we are enabling triggered buffer or the touchscreen */
897 if (bitmap_subset(indio_dev->active_scan_mask,
898 &st->touch_st.channels_bitmask,
899 AT91_SAMA5D2_MAX_CHAN_IDX + 1)) {
900 /* touchscreen enabling */
901 return at91_adc_configure_touch(st, true);
902 }
903 /* if we are not in triggered mode, we cannot enable the buffer. */
904 if (!(indio_dev->currentmode & INDIO_ALL_TRIGGERED_MODES))
905 return -EINVAL;
906
907 /* we continue with the triggered buffer */
908 ret = at91_adc_dma_start(indio_dev);
909 if (ret) {
910 dev_err(&indio_dev->dev, "buffer postenable failed\n");
911 return ret;
912 }
913
914 return iio_triggered_buffer_postenable(indio_dev);
915 }
916
917 static int at91_adc_buffer_predisable(struct iio_dev *indio_dev)
918 {
919 struct at91_adc_state *st = iio_priv(indio_dev);
920 int ret;
921 u8 bit;
922
923 /* check if we are disabling triggered buffer or the touchscreen */
924 if (bitmap_subset(indio_dev->active_scan_mask,
925 &st->touch_st.channels_bitmask,
926 AT91_SAMA5D2_MAX_CHAN_IDX + 1)) {
927 /* touchscreen disable */
928 return at91_adc_configure_touch(st, false);
929 }
930 /* if we are not in triggered mode, nothing to do here */
931 if (!(indio_dev->currentmode & INDIO_ALL_TRIGGERED_MODES))
932 return -EINVAL;
933
934 /* continue with the triggered buffer */
935 ret = iio_triggered_buffer_predisable(indio_dev);
936 if (ret < 0)
937 dev_err(&indio_dev->dev, "buffer predisable failed\n");
938
939 if (!st->dma_st.dma_chan)
940 return ret;
941
942 /* if we are using DMA we must clear registers and end DMA */
943 dmaengine_terminate_sync(st->dma_st.dma_chan);
944
945 /*
946 * For each enabled channel we must read the last converted value
947 * to clear EOC status and not get a possible interrupt later.
948 * This value is being read by DMA from LCDR anyway
949 */
950 for_each_set_bit(bit, indio_dev->active_scan_mask,
951 indio_dev->num_channels) {
952 struct iio_chan_spec const *chan =
953 at91_adc_chan_get(indio_dev, bit);
954
955 if (!chan)
956 continue;
957 /* these channel types are virtual, no need to do anything */
958 if (chan->type == IIO_POSITIONRELATIVE ||
959 chan->type == IIO_PRESSURE)
960 continue;
961 if (st->dma_st.dma_chan)
962 at91_adc_readl(st, chan->address);
963 }
964
965 /* read overflow register to clear possible overflow status */
966 at91_adc_readl(st, AT91_SAMA5D2_OVER);
967 return ret;
968 }
969
970 static const struct iio_buffer_setup_ops at91_buffer_setup_ops = {
971 .postenable = &at91_adc_buffer_postenable,
972 .predisable = &at91_adc_buffer_predisable,
973 };
974
975 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio,
976 char *trigger_name)
977 {
978 struct iio_trigger *trig;
979 int ret;
980
981 trig = devm_iio_trigger_alloc(&indio->dev, "%s-dev%d-%s", indio->name,
982 indio->id, trigger_name);
983 if (!trig)
984 return NULL;
985
986 trig->dev.parent = indio->dev.parent;
987 iio_trigger_set_drvdata(trig, indio);
988 trig->ops = &at91_adc_trigger_ops;
989
990 ret = devm_iio_trigger_register(&indio->dev, trig);
991 if (ret)
992 return ERR_PTR(ret);
993
994 return trig;
995 }
996
997 static int at91_adc_trigger_init(struct iio_dev *indio)
998 {
999 struct at91_adc_state *st = iio_priv(indio);
1000
1001 st->trig = at91_adc_allocate_trigger(indio, st->selected_trig->name);
1002 if (IS_ERR(st->trig)) {
1003 dev_err(&indio->dev,
1004 "could not allocate trigger\n");
1005 return PTR_ERR(st->trig);
1006 }
1007
1008 return 0;
1009 }
1010
1011 static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
1012 struct iio_poll_func *pf)
1013 {
1014 struct at91_adc_state *st = iio_priv(indio_dev);
1015 int i = 0;
1016 int val;
1017 u8 bit;
1018
1019 for_each_set_bit(bit, indio_dev->active_scan_mask,
1020 indio_dev->num_channels) {
1021 struct iio_chan_spec const *chan =
1022 at91_adc_chan_get(indio_dev, bit);
1023
1024 if (!chan)
1025 continue;
1026 /*
1027 * Our external trigger only supports the voltage channels.
1028 * In case someone requested a different type of channel
1029 * just put zeroes to buffer.
1030 * This should not happen because we check the scan mode
1031 * and scan mask when we enable the buffer, and we don't allow
1032 * the buffer to start with a mixed mask (voltage and something
1033 * else).
1034 * Thus, emit a warning.
1035 */
1036 if (chan->type == IIO_VOLTAGE) {
1037 val = at91_adc_readl(st, chan->address);
1038 at91_adc_adjust_val_osr(st, &val);
1039 st->buffer[i] = val;
1040 } else {
1041 st->buffer[i] = 0;
1042 WARN(true, "This trigger cannot handle this type of channel");
1043 }
1044 i++;
1045 }
1046 iio_push_to_buffers_with_timestamp(indio_dev, st->buffer,
1047 pf->timestamp);
1048 }
1049
1050 static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev)
1051 {
1052 struct at91_adc_state *st = iio_priv(indio_dev);
1053 int transferred_len = at91_adc_dma_size_done(st);
1054 s64 ns = iio_get_time_ns(indio_dev);
1055 s64 interval;
1056 int sample_index = 0, sample_count, sample_size;
1057
1058 u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
1059 /* if we reached this point, we cannot sample faster */
1060 if (status & AT91_SAMA5D2_IER_GOVRE)
1061 pr_info_ratelimited("%s: conversion overrun detected\n",
1062 indio_dev->name);
1063
1064 sample_size = div_s64(st->dma_st.rx_buf_sz, st->dma_st.watermark);
1065
1066 sample_count = div_s64(transferred_len, sample_size);
1067
1068 /*
1069 * interval between samples is total time since last transfer handling
1070 * divided by the number of samples (total size divided by sample size)
1071 */
1072 interval = div_s64((ns - st->dma_st.dma_ts), sample_count);
1073
1074 while (transferred_len >= sample_size) {
1075 /*
1076 * for all the values in the current sample,
1077 * adjust the values inside the buffer for oversampling
1078 */
1079 at91_adc_adjust_val_osr_array(st,
1080 &st->dma_st.rx_buf[st->dma_st.buf_idx],
1081 sample_size);
1082
1083 iio_push_to_buffers_with_timestamp(indio_dev,
1084 (st->dma_st.rx_buf + st->dma_st.buf_idx),
1085 (st->dma_st.dma_ts + interval * sample_index));
1086 /* adjust remaining length */
1087 transferred_len -= sample_size;
1088 /* adjust buffer index */
1089 st->dma_st.buf_idx += sample_size;
1090 /* in case of reaching end of buffer, reset index */
1091 if (st->dma_st.buf_idx >= st->dma_st.rx_buf_sz)
1092 st->dma_st.buf_idx = 0;
1093 sample_index++;
1094 }
1095 /* adjust saved time for next transfer handling */
1096 st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
1097 }
1098
1099 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
1100 {
1101 struct iio_poll_func *pf = p;
1102 struct iio_dev *indio_dev = pf->indio_dev;
1103 struct at91_adc_state *st = iio_priv(indio_dev);
1104
1105 if (st->dma_st.dma_chan)
1106 at91_adc_trigger_handler_dma(indio_dev);
1107 else
1108 at91_adc_trigger_handler_nodma(indio_dev, pf);
1109
1110 iio_trigger_notify_done(indio_dev->trig);
1111
1112 return IRQ_HANDLED;
1113 }
1114
1115 static int at91_adc_buffer_init(struct iio_dev *indio)
1116 {
1117 struct at91_adc_state *st = iio_priv(indio);
1118
1119 if (st->selected_trig->hw_trig) {
1120 return devm_iio_triggered_buffer_setup(&indio->dev, indio,
1121 &iio_pollfunc_store_time,
1122 &at91_adc_trigger_handler, &at91_buffer_setup_ops);
1123 }
1124 /*
1125 * we need to prepare the buffer ops in case we will get
1126 * another buffer attached (like a callback buffer for the touchscreen)
1127 */
1128 indio->setup_ops = &at91_buffer_setup_ops;
1129
1130 return 0;
1131 }
1132
1133 static unsigned at91_adc_startup_time(unsigned startup_time_min,
1134 unsigned adc_clk_khz)
1135 {
1136 static const unsigned int startup_lookup[] = {
1137 0, 8, 16, 24,
1138 64, 80, 96, 112,
1139 512, 576, 640, 704,
1140 768, 832, 896, 960
1141 };
1142 unsigned ticks_min, i;
1143
1144 /*
1145 * Since the adc frequency is checked before, there is no reason
1146 * to not meet the startup time constraint.
1147 */
1148
1149 ticks_min = startup_time_min * adc_clk_khz / 1000;
1150 for (i = 0; i < ARRAY_SIZE(startup_lookup); i++)
1151 if (startup_lookup[i] > ticks_min)
1152 break;
1153
1154 return i;
1155 }
1156
1157 static void at91_adc_setup_samp_freq(struct at91_adc_state *st, unsigned freq)
1158 {
1159 struct iio_dev *indio_dev = iio_priv_to_dev(st);
1160 unsigned f_per, prescal, startup, mr;
1161
1162 f_per = clk_get_rate(st->per_clk);
1163 prescal = (f_per / (2 * freq)) - 1;
1164
1165 startup = at91_adc_startup_time(st->soc_info.startup_time,
1166 freq / 1000);
1167
1168 mr = at91_adc_readl(st, AT91_SAMA5D2_MR);
1169 mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK);
1170 mr |= AT91_SAMA5D2_MR_STARTUP(startup);
1171 mr |= AT91_SAMA5D2_MR_PRESCAL(prescal);
1172 at91_adc_writel(st, AT91_SAMA5D2_MR, mr);
1173
1174 dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n",
1175 freq, startup, prescal);
1176 st->current_sample_rate = freq;
1177 }
1178
1179 static inline unsigned at91_adc_get_sample_freq(struct at91_adc_state *st)
1180 {
1181 return st->current_sample_rate;
1182 }
1183
1184 static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
1185 {
1186 struct at91_adc_state *st = iio_priv(indio_dev);
1187 u8 bit;
1188 u16 val;
1189 int i = 0;
1190
1191 for_each_set_bit(bit, indio_dev->active_scan_mask,
1192 AT91_SAMA5D2_MAX_CHAN_IDX + 1) {
1193 struct iio_chan_spec const *chan =
1194 at91_adc_chan_get(indio_dev, bit);
1195
1196 if (chan->type == IIO_POSITIONRELATIVE)
1197 at91_adc_read_position(st, chan->channel, &val);
1198 else if (chan->type == IIO_PRESSURE)
1199 at91_adc_read_pressure(st, chan->channel, &val);
1200 else
1201 continue;
1202 st->buffer[i] = val;
1203 i++;
1204 }
1205 /*
1206 * Schedule work to push to buffers.
1207 * This is intended to push to the callback buffer that another driver
1208 * registered. We are still in a handler from our IRQ. If we push
1209 * directly, it means the other driver has it's callback called
1210 * from our IRQ context. Which is something we better avoid.
1211 * Let's schedule it after our IRQ is completed.
1212 */
1213 schedule_work(&st->touch_st.workq);
1214 }
1215
1216 static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st)
1217 {
1218 at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_PEN);
1219 at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_NOPEN |
1220 AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1221 AT91_SAMA5D2_IER_PRDY);
1222 at91_adc_writel(st, AT91_SAMA5D2_TRGR,
1223 AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
1224 AT91_SAMA5D2_TRGR_TRGPER(st->touch_st.sample_period_val));
1225 st->touch_st.touching = true;
1226 }
1227
1228 static void at91_adc_no_pen_detect_interrupt(struct at91_adc_state *st)
1229 {
1230 struct iio_dev *indio_dev = iio_priv_to_dev(st);
1231
1232 at91_adc_writel(st, AT91_SAMA5D2_TRGR,
1233 AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
1234 at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_NOPEN |
1235 AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1236 AT91_SAMA5D2_IER_PRDY);
1237 st->touch_st.touching = false;
1238
1239 at91_adc_touch_data_handler(indio_dev);
1240
1241 at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN);
1242 }
1243
1244 static void at91_adc_workq_handler(struct work_struct *workq)
1245 {
1246 struct at91_adc_touch *touch_st = container_of(workq,
1247 struct at91_adc_touch, workq);
1248 struct at91_adc_state *st = container_of(touch_st,
1249 struct at91_adc_state, touch_st);
1250 struct iio_dev *indio_dev = iio_priv_to_dev(st);
1251
1252 iio_push_to_buffers(indio_dev, st->buffer);
1253 }
1254
1255 static irqreturn_t at91_adc_interrupt(int irq, void *private)
1256 {
1257 struct iio_dev *indio = private;
1258 struct at91_adc_state *st = iio_priv(indio);
1259 u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
1260 u32 imr = at91_adc_readl(st, AT91_SAMA5D2_IMR);
1261 u32 rdy_mask = AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1262 AT91_SAMA5D2_IER_PRDY;
1263
1264 if (!(status & imr))
1265 return IRQ_NONE;
1266 if (status & AT91_SAMA5D2_IER_PEN) {
1267 /* pen detected IRQ */
1268 at91_adc_pen_detect_interrupt(st);
1269 } else if ((status & AT91_SAMA5D2_IER_NOPEN)) {
1270 /* nopen detected IRQ */
1271 at91_adc_no_pen_detect_interrupt(st);
1272 } else if ((status & AT91_SAMA5D2_ISR_PENS) &&
1273 ((status & rdy_mask) == rdy_mask)) {
1274 /* periodic trigger IRQ - during pen sense */
1275 at91_adc_touch_data_handler(indio);
1276 } else if (status & AT91_SAMA5D2_ISR_PENS) {
1277 /*
1278 * touching, but the measurements are not ready yet.
1279 * read and ignore.
1280 */
1281 status = at91_adc_readl(st, AT91_SAMA5D2_XPOSR);
1282 status = at91_adc_readl(st, AT91_SAMA5D2_YPOSR);
1283 status = at91_adc_readl(st, AT91_SAMA5D2_PRESSR);
1284 } else if (iio_buffer_enabled(indio) && !st->dma_st.dma_chan) {
1285 /* triggered buffer without DMA */
1286 disable_irq_nosync(irq);
1287 iio_trigger_poll(indio->trig);
1288 } else if (iio_buffer_enabled(indio) && st->dma_st.dma_chan) {
1289 /* triggered buffer with DMA - should not happen */
1290 disable_irq_nosync(irq);
1291 WARN(true, "Unexpected irq occurred\n");
1292 } else if (!iio_buffer_enabled(indio)) {
1293 /* software requested conversion */
1294 st->conversion_value = at91_adc_readl(st, st->chan->address);
1295 st->conversion_done = true;
1296 wake_up_interruptible(&st->wq_data_available);
1297 }
1298 return IRQ_HANDLED;
1299 }
1300
1301 static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
1302 struct iio_chan_spec const *chan, int *val)
1303 {
1304 struct at91_adc_state *st = iio_priv(indio_dev);
1305 u32 cor = 0;
1306 u16 tmp_val;
1307 int ret;
1308
1309 /*
1310 * Keep in mind that we cannot use software trigger or touchscreen
1311 * if external trigger is enabled
1312 */
1313 if (chan->type == IIO_POSITIONRELATIVE) {
1314 ret = iio_device_claim_direct_mode(indio_dev);
1315 if (ret)
1316 return ret;
1317 mutex_lock(&st->lock);
1318
1319 ret = at91_adc_read_position(st, chan->channel,
1320 &tmp_val);
1321 *val = tmp_val;
1322 mutex_unlock(&st->lock);
1323 iio_device_release_direct_mode(indio_dev);
1324
1325 return at91_adc_adjust_val_osr(st, val);
1326 }
1327 if (chan->type == IIO_PRESSURE) {
1328 ret = iio_device_claim_direct_mode(indio_dev);
1329 if (ret)
1330 return ret;
1331 mutex_lock(&st->lock);
1332
1333 ret = at91_adc_read_pressure(st, chan->channel,
1334 &tmp_val);
1335 *val = tmp_val;
1336 mutex_unlock(&st->lock);
1337 iio_device_release_direct_mode(indio_dev);
1338
1339 return at91_adc_adjust_val_osr(st, val);
1340 }
1341
1342 /* in this case we have a voltage channel */
1343
1344 ret = iio_device_claim_direct_mode(indio_dev);
1345 if (ret)
1346 return ret;
1347 mutex_lock(&st->lock);
1348
1349 st->chan = chan;
1350
1351 if (chan->differential)
1352 cor = (BIT(chan->channel) | BIT(chan->channel2)) <<
1353 AT91_SAMA5D2_COR_DIFF_OFFSET;
1354
1355 at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
1356 at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
1357 at91_adc_writel(st, AT91_SAMA5D2_IER, BIT(chan->channel));
1358 at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START);
1359
1360 ret = wait_event_interruptible_timeout(st->wq_data_available,
1361 st->conversion_done,
1362 msecs_to_jiffies(1000));
1363 if (ret == 0)
1364 ret = -ETIMEDOUT;
1365
1366 if (ret > 0) {
1367 *val = st->conversion_value;
1368 ret = at91_adc_adjust_val_osr(st, val);
1369 if (chan->scan_type.sign == 's')
1370 *val = sign_extend32(*val, 11);
1371 st->conversion_done = false;
1372 }
1373
1374 at91_adc_writel(st, AT91_SAMA5D2_IDR, BIT(chan->channel));
1375 at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
1376
1377 /* Needed to ACK the DRDY interruption */
1378 at91_adc_readl(st, AT91_SAMA5D2_LCDR);
1379
1380 mutex_unlock(&st->lock);
1381
1382 iio_device_release_direct_mode(indio_dev);
1383 return ret;
1384 }
1385
1386 static int at91_adc_read_raw(struct iio_dev *indio_dev,
1387 struct iio_chan_spec const *chan,
1388 int *val, int *val2, long mask)
1389 {
1390 struct at91_adc_state *st = iio_priv(indio_dev);
1391
1392 switch (mask) {
1393 case IIO_CHAN_INFO_RAW:
1394 return at91_adc_read_info_raw(indio_dev, chan, val);
1395 case IIO_CHAN_INFO_SCALE:
1396 *val = st->vref_uv / 1000;
1397 if (chan->differential)
1398 *val *= 2;
1399 *val2 = chan->scan_type.realbits;
1400 return IIO_VAL_FRACTIONAL_LOG2;
1401
1402 case IIO_CHAN_INFO_SAMP_FREQ:
1403 *val = at91_adc_get_sample_freq(st);
1404 return IIO_VAL_INT;
1405
1406 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1407 *val = st->oversampling_ratio;
1408 return IIO_VAL_INT;
1409
1410 default:
1411 return -EINVAL;
1412 }
1413 }
1414
1415 static int at91_adc_write_raw(struct iio_dev *indio_dev,
1416 struct iio_chan_spec const *chan,
1417 int val, int val2, long mask)
1418 {
1419 struct at91_adc_state *st = iio_priv(indio_dev);
1420
1421 switch (mask) {
1422 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1423 if ((val != AT91_OSR_1SAMPLES) && (val != AT91_OSR_4SAMPLES) &&
1424 (val != AT91_OSR_16SAMPLES))
1425 return -EINVAL;
1426 /* if no change, optimize out */
1427 if (val == st->oversampling_ratio)
1428 return 0;
1429 st->oversampling_ratio = val;
1430 /* update ratio */
1431 at91_adc_config_emr(st);
1432 return 0;
1433 case IIO_CHAN_INFO_SAMP_FREQ:
1434 if (val < st->soc_info.min_sample_rate ||
1435 val > st->soc_info.max_sample_rate)
1436 return -EINVAL;
1437
1438 at91_adc_setup_samp_freq(st, val);
1439 return 0;
1440 default:
1441 return -EINVAL;
1442 };
1443 }
1444
1445 static void at91_adc_dma_init(struct platform_device *pdev)
1446 {
1447 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1448 struct at91_adc_state *st = iio_priv(indio_dev);
1449 struct dma_slave_config config = {0};
1450 /*
1451 * We make the buffer double the size of the fifo,
1452 * such that DMA uses one half of the buffer (full fifo size)
1453 * and the software uses the other half to read/write.
1454 */
1455 unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
1456 AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
1457 PAGE_SIZE);
1458
1459 if (st->dma_st.dma_chan)
1460 return;
1461
1462 st->dma_st.dma_chan = dma_request_chan(&pdev->dev, "rx");
1463 if (IS_ERR(st->dma_st.dma_chan)) {
1464 dev_info(&pdev->dev, "can't get DMA channel\n");
1465 st->dma_st.dma_chan = NULL;
1466 goto dma_exit;
1467 }
1468
1469 st->dma_st.rx_buf = dma_alloc_coherent(st->dma_st.dma_chan->device->dev,
1470 pages * PAGE_SIZE,
1471 &st->dma_st.rx_dma_buf,
1472 GFP_KERNEL);
1473 if (!st->dma_st.rx_buf) {
1474 dev_info(&pdev->dev, "can't allocate coherent DMA area\n");
1475 goto dma_chan_disable;
1476 }
1477
1478 /* Configure DMA channel to read data register */
1479 config.direction = DMA_DEV_TO_MEM;
1480 config.src_addr = (phys_addr_t)(st->dma_st.phys_addr
1481 + AT91_SAMA5D2_LCDR);
1482 config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1483 config.src_maxburst = 1;
1484 config.dst_maxburst = 1;
1485
1486 if (dmaengine_slave_config(st->dma_st.dma_chan, &config)) {
1487 dev_info(&pdev->dev, "can't configure DMA slave\n");
1488 goto dma_free_area;
1489 }
1490
1491 dev_info(&pdev->dev, "using %s for rx DMA transfers\n",
1492 dma_chan_name(st->dma_st.dma_chan));
1493
1494 return;
1495
1496 dma_free_area:
1497 dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
1498 st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
1499 dma_chan_disable:
1500 dma_release_channel(st->dma_st.dma_chan);
1501 st->dma_st.dma_chan = NULL;
1502 dma_exit:
1503 dev_info(&pdev->dev, "continuing without DMA support\n");
1504 }
1505
1506 static void at91_adc_dma_disable(struct platform_device *pdev)
1507 {
1508 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1509 struct at91_adc_state *st = iio_priv(indio_dev);
1510 unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
1511 AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
1512 PAGE_SIZE);
1513
1514 /* if we are not using DMA, just return */
1515 if (!st->dma_st.dma_chan)
1516 return;
1517
1518 /* wait for all transactions to be terminated first*/
1519 dmaengine_terminate_sync(st->dma_st.dma_chan);
1520
1521 dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
1522 st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
1523 dma_release_channel(st->dma_st.dma_chan);
1524 st->dma_st.dma_chan = NULL;
1525
1526 dev_info(&pdev->dev, "continuing without DMA support\n");
1527 }
1528
1529 static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
1530 {
1531 struct at91_adc_state *st = iio_priv(indio_dev);
1532
1533 if (val > AT91_HWFIFO_MAX_SIZE)
1534 return -EINVAL;
1535
1536 if (!st->selected_trig->hw_trig) {
1537 dev_dbg(&indio_dev->dev, "we need hw trigger for DMA\n");
1538 return 0;
1539 }
1540
1541 dev_dbg(&indio_dev->dev, "new watermark is %u\n", val);
1542 st->dma_st.watermark = val;
1543
1544 /*
1545 * The logic here is: if we have watermark 1, it means we do
1546 * each conversion with it's own IRQ, thus we don't need DMA.
1547 * If the watermark is higher, we do DMA to do all the transfers in bulk
1548 */
1549
1550 if (val == 1)
1551 at91_adc_dma_disable(to_platform_device(&indio_dev->dev));
1552 else if (val > 1)
1553 at91_adc_dma_init(to_platform_device(&indio_dev->dev));
1554
1555 return 0;
1556 }
1557
1558 static int at91_adc_update_scan_mode(struct iio_dev *indio_dev,
1559 const unsigned long *scan_mask)
1560 {
1561 struct at91_adc_state *st = iio_priv(indio_dev);
1562
1563 if (bitmap_subset(scan_mask, &st->touch_st.channels_bitmask,
1564 AT91_SAMA5D2_MAX_CHAN_IDX + 1))
1565 return 0;
1566 /*
1567 * if the new bitmap is a combination of touchscreen and regular
1568 * channels, then we are not fine
1569 */
1570 if (bitmap_intersects(&st->touch_st.channels_bitmask, scan_mask,
1571 AT91_SAMA5D2_MAX_CHAN_IDX + 1))
1572 return -EINVAL;
1573 return 0;
1574 }
1575
1576 static void at91_adc_hw_init(struct at91_adc_state *st)
1577 {
1578 at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
1579 at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff);
1580 /*
1581 * Transfer field must be set to 2 according to the datasheet and
1582 * allows different analog settings for each channel.
1583 */
1584 at91_adc_writel(st, AT91_SAMA5D2_MR,
1585 AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH);
1586
1587 at91_adc_setup_samp_freq(st, st->soc_info.min_sample_rate);
1588
1589 /* configure extended mode register */
1590 at91_adc_config_emr(st);
1591 }
1592
1593 static ssize_t at91_adc_get_fifo_state(struct device *dev,
1594 struct device_attribute *attr, char *buf)
1595 {
1596 struct iio_dev *indio_dev = dev_get_drvdata(dev);
1597 struct at91_adc_state *st = iio_priv(indio_dev);
1598
1599 return scnprintf(buf, PAGE_SIZE, "%d\n", !!st->dma_st.dma_chan);
1600 }
1601
1602 static ssize_t at91_adc_get_watermark(struct device *dev,
1603 struct device_attribute *attr, char *buf)
1604 {
1605 struct iio_dev *indio_dev = dev_get_drvdata(dev);
1606 struct at91_adc_state *st = iio_priv(indio_dev);
1607
1608 return scnprintf(buf, PAGE_SIZE, "%d\n", st->dma_st.watermark);
1609 }
1610
1611 static IIO_DEVICE_ATTR(hwfifo_enabled, 0444,
1612 at91_adc_get_fifo_state, NULL, 0);
1613 static IIO_DEVICE_ATTR(hwfifo_watermark, 0444,
1614 at91_adc_get_watermark, NULL, 0);
1615
1616 static IIO_CONST_ATTR(hwfifo_watermark_min, "2");
1617 static IIO_CONST_ATTR(hwfifo_watermark_max, AT91_HWFIFO_MAX_SIZE_STR);
1618
1619 static IIO_CONST_ATTR(oversampling_ratio_available,
1620 __stringify(AT91_OSR_1SAMPLES) " "
1621 __stringify(AT91_OSR_4SAMPLES) " "
1622 __stringify(AT91_OSR_16SAMPLES));
1623
1624 static struct attribute *at91_adc_attributes[] = {
1625 &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
1626 NULL,
1627 };
1628
1629 static const struct attribute_group at91_adc_attribute_group = {
1630 .attrs = at91_adc_attributes,
1631 };
1632
1633 static const struct attribute *at91_adc_fifo_attributes[] = {
1634 &iio_const_attr_hwfifo_watermark_min.dev_attr.attr,
1635 &iio_const_attr_hwfifo_watermark_max.dev_attr.attr,
1636 &iio_dev_attr_hwfifo_watermark.dev_attr.attr,
1637 &iio_dev_attr_hwfifo_enabled.dev_attr.attr,
1638 NULL,
1639 };
1640
1641 static const struct iio_info at91_adc_info = {
1642 .attrs = &at91_adc_attribute_group,
1643 .read_raw = &at91_adc_read_raw,
1644 .write_raw = &at91_adc_write_raw,
1645 .update_scan_mode = &at91_adc_update_scan_mode,
1646 .of_xlate = &at91_adc_of_xlate,
1647 .hwfifo_set_watermark = &at91_adc_set_watermark,
1648 };
1649
1650 static int at91_adc_probe(struct platform_device *pdev)
1651 {
1652 struct iio_dev *indio_dev;
1653 struct at91_adc_state *st;
1654 struct resource *res;
1655 int ret, i;
1656 u32 edge_type = IRQ_TYPE_NONE;
1657
1658 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
1659 if (!indio_dev)
1660 return -ENOMEM;
1661
1662 indio_dev->dev.parent = &pdev->dev;
1663 indio_dev->name = dev_name(&pdev->dev);
1664 indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
1665 indio_dev->info = &at91_adc_info;
1666 indio_dev->channels = at91_adc_channels;
1667 indio_dev->num_channels = ARRAY_SIZE(at91_adc_channels);
1668
1669 st = iio_priv(indio_dev);
1670
1671 bitmap_set(&st->touch_st.channels_bitmask,
1672 AT91_SAMA5D2_TOUCH_X_CHAN_IDX, 1);
1673 bitmap_set(&st->touch_st.channels_bitmask,
1674 AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, 1);
1675 bitmap_set(&st->touch_st.channels_bitmask,
1676 AT91_SAMA5D2_TOUCH_P_CHAN_IDX, 1);
1677
1678 st->oversampling_ratio = AT91_OSR_1SAMPLES;
1679
1680 ret = of_property_read_u32(pdev->dev.of_node,
1681 "atmel,min-sample-rate-hz",
1682 &st->soc_info.min_sample_rate);
1683 if (ret) {
1684 dev_err(&pdev->dev,
1685 "invalid or missing value for atmel,min-sample-rate-hz\n");
1686 return ret;
1687 }
1688
1689 ret = of_property_read_u32(pdev->dev.of_node,
1690 "atmel,max-sample-rate-hz",
1691 &st->soc_info.max_sample_rate);
1692 if (ret) {
1693 dev_err(&pdev->dev,
1694 "invalid or missing value for atmel,max-sample-rate-hz\n");
1695 return ret;
1696 }
1697
1698 ret = of_property_read_u32(pdev->dev.of_node, "atmel,startup-time-ms",
1699 &st->soc_info.startup_time);
1700 if (ret) {
1701 dev_err(&pdev->dev,
1702 "invalid or missing value for atmel,startup-time-ms\n");
1703 return ret;
1704 }
1705
1706 ret = of_property_read_u32(pdev->dev.of_node,
1707 "atmel,trigger-edge-type", &edge_type);
1708 if (ret) {
1709 dev_dbg(&pdev->dev,
1710 "atmel,trigger-edge-type not specified, only software trigger available\n");
1711 }
1712
1713 st->selected_trig = NULL;
1714
1715 /* find the right trigger, or no trigger at all */
1716 for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT + 1; i++)
1717 if (at91_adc_trigger_list[i].edge_type == edge_type) {
1718 st->selected_trig = &at91_adc_trigger_list[i];
1719 break;
1720 }
1721
1722 if (!st->selected_trig) {
1723 dev_err(&pdev->dev, "invalid external trigger edge value\n");
1724 return -EINVAL;
1725 }
1726
1727 init_waitqueue_head(&st->wq_data_available);
1728 mutex_init(&st->lock);
1729 INIT_WORK(&st->touch_st.workq, at91_adc_workq_handler);
1730
1731 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1732 if (!res)
1733 return -EINVAL;
1734
1735 /* if we plan to use DMA, we need the physical address of the regs */
1736 st->dma_st.phys_addr = res->start;
1737
1738 st->base = devm_ioremap_resource(&pdev->dev, res);
1739 if (IS_ERR(st->base))
1740 return PTR_ERR(st->base);
1741
1742 st->irq = platform_get_irq(pdev, 0);
1743 if (st->irq <= 0) {
1744 if (!st->irq)
1745 st->irq = -ENXIO;
1746
1747 return st->irq;
1748 }
1749
1750 st->per_clk = devm_clk_get(&pdev->dev, "adc_clk");
1751 if (IS_ERR(st->per_clk))
1752 return PTR_ERR(st->per_clk);
1753
1754 st->reg = devm_regulator_get(&pdev->dev, "vddana");
1755 if (IS_ERR(st->reg))
1756 return PTR_ERR(st->reg);
1757
1758 st->vref = devm_regulator_get(&pdev->dev, "vref");
1759 if (IS_ERR(st->vref))
1760 return PTR_ERR(st->vref);
1761
1762 ret = devm_request_irq(&pdev->dev, st->irq, at91_adc_interrupt, 0,
1763 pdev->dev.driver->name, indio_dev);
1764 if (ret)
1765 return ret;
1766
1767 ret = regulator_enable(st->reg);
1768 if (ret)
1769 return ret;
1770
1771 ret = regulator_enable(st->vref);
1772 if (ret)
1773 goto reg_disable;
1774
1775 st->vref_uv = regulator_get_voltage(st->vref);
1776 if (st->vref_uv <= 0) {
1777 ret = -EINVAL;
1778 goto vref_disable;
1779 }
1780
1781 at91_adc_hw_init(st);
1782
1783 ret = clk_prepare_enable(st->per_clk);
1784 if (ret)
1785 goto vref_disable;
1786
1787 platform_set_drvdata(pdev, indio_dev);
1788
1789 ret = at91_adc_buffer_init(indio_dev);
1790 if (ret < 0) {
1791 dev_err(&pdev->dev, "couldn't initialize the buffer.\n");
1792 goto per_clk_disable_unprepare;
1793 }
1794
1795 if (st->selected_trig->hw_trig) {
1796 ret = at91_adc_trigger_init(indio_dev);
1797 if (ret < 0) {
1798 dev_err(&pdev->dev, "couldn't setup the triggers.\n");
1799 goto per_clk_disable_unprepare;
1800 }
1801 /*
1802 * Initially the iio buffer has a length of 2 and
1803 * a watermark of 1
1804 */
1805 st->dma_st.watermark = 1;
1806
1807 iio_buffer_set_attrs(indio_dev->buffer,
1808 at91_adc_fifo_attributes);
1809 }
1810
1811 if (dma_coerce_mask_and_coherent(&indio_dev->dev, DMA_BIT_MASK(32)))
1812 dev_info(&pdev->dev, "cannot set DMA mask to 32-bit\n");
1813
1814 ret = iio_device_register(indio_dev);
1815 if (ret < 0)
1816 goto dma_disable;
1817
1818 if (st->selected_trig->hw_trig)
1819 dev_info(&pdev->dev, "setting up trigger as %s\n",
1820 st->selected_trig->name);
1821
1822 dev_info(&pdev->dev, "version: %x\n",
1823 readl_relaxed(st->base + AT91_SAMA5D2_VERSION));
1824
1825 return 0;
1826
1827 dma_disable:
1828 at91_adc_dma_disable(pdev);
1829 per_clk_disable_unprepare:
1830 clk_disable_unprepare(st->per_clk);
1831 vref_disable:
1832 regulator_disable(st->vref);
1833 reg_disable:
1834 regulator_disable(st->reg);
1835 return ret;
1836 }
1837
1838 static int at91_adc_remove(struct platform_device *pdev)
1839 {
1840 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1841 struct at91_adc_state *st = iio_priv(indio_dev);
1842
1843 iio_device_unregister(indio_dev);
1844
1845 at91_adc_dma_disable(pdev);
1846
1847 clk_disable_unprepare(st->per_clk);
1848
1849 regulator_disable(st->vref);
1850 regulator_disable(st->reg);
1851
1852 return 0;
1853 }
1854
1855 static __maybe_unused int at91_adc_suspend(struct device *dev)
1856 {
1857 struct iio_dev *indio_dev = dev_get_drvdata(dev);
1858 struct at91_adc_state *st = iio_priv(indio_dev);
1859
1860 /*
1861 * Do a sofware reset of the ADC before we go to suspend.
1862 * this will ensure that all pins are free from being muxed by the ADC
1863 * and can be used by for other devices.
1864 * Otherwise, ADC will hog them and we can't go to suspend mode.
1865 */
1866 at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
1867
1868 clk_disable_unprepare(st->per_clk);
1869 regulator_disable(st->vref);
1870 regulator_disable(st->reg);
1871
1872 return pinctrl_pm_select_sleep_state(dev);
1873 }
1874
1875 static __maybe_unused int at91_adc_resume(struct device *dev)
1876 {
1877 struct iio_dev *indio_dev = dev_get_drvdata(dev);
1878 struct at91_adc_state *st = iio_priv(indio_dev);
1879 int ret;
1880
1881 ret = pinctrl_pm_select_default_state(dev);
1882 if (ret)
1883 goto resume_failed;
1884
1885 ret = regulator_enable(st->reg);
1886 if (ret)
1887 goto resume_failed;
1888
1889 ret = regulator_enable(st->vref);
1890 if (ret)
1891 goto reg_disable_resume;
1892
1893 ret = clk_prepare_enable(st->per_clk);
1894 if (ret)
1895 goto vref_disable_resume;
1896
1897 at91_adc_hw_init(st);
1898
1899 /* reconfiguring trigger hardware state */
1900 if (!iio_buffer_enabled(indio_dev))
1901 return 0;
1902
1903 /* check if we are enabling triggered buffer or the touchscreen */
1904 if (bitmap_subset(indio_dev->active_scan_mask,
1905 &st->touch_st.channels_bitmask,
1906 AT91_SAMA5D2_MAX_CHAN_IDX + 1)) {
1907 /* touchscreen enabling */
1908 return at91_adc_configure_touch(st, true);
1909 } else {
1910 return at91_adc_configure_trigger(st->trig, true);
1911 }
1912
1913 /* not needed but more explicit */
1914 return 0;
1915
1916 vref_disable_resume:
1917 regulator_disable(st->vref);
1918 reg_disable_resume:
1919 regulator_disable(st->reg);
1920 resume_failed:
1921 dev_err(&indio_dev->dev, "failed to resume\n");
1922 return ret;
1923 }
1924
1925 static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume);
1926
1927 static const struct of_device_id at91_adc_dt_match[] = {
1928 {
1929 .compatible = "atmel,sama5d2-adc",
1930 }, {
1931 /* sentinel */
1932 }
1933 };
1934 MODULE_DEVICE_TABLE(of, at91_adc_dt_match);
1935
1936 static struct platform_driver at91_adc_driver = {
1937 .probe = at91_adc_probe,
1938 .remove = at91_adc_remove,
1939 .driver = {
1940 .name = "at91-sama5d2_adc",
1941 .of_match_table = at91_adc_dt_match,
1942 .pm = &at91_adc_pm_ops,
1943 },
1944 };
1945 module_platform_driver(at91_adc_driver)
1946
1947 MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>");
1948 MODULE_DESCRIPTION("Atmel AT91 SAMA5D2 ADC");
1949 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support