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  *		 2021 Microchip Technology, Inc. and its subsidiaries
8  *		 2021 Eugen Hristev <eugen.hristev@microchip.com>
9  */
10 
11 #include <linux/bitops.h>
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/dmaengine.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/module.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/platform_device.h>
21 #include <linux/property.h>
22 #include <linux/sched.h>
23 #include <linux/units.h>
24 #include <linux/wait.h>
25 #include <linux/iio/iio.h>
26 #include <linux/iio/sysfs.h>
27 #include <linux/iio/buffer.h>
28 #include <linux/iio/trigger.h>
29 #include <linux/iio/trigger_consumer.h>
30 #include <linux/iio/triggered_buffer.h>
31 #include <linux/nvmem-consumer.h>
32 #include <linux/pinctrl/consumer.h>
33 #include <linux/pm_runtime.h>
34 #include <linux/regulator/consumer.h>
35 
36 #include <dt-bindings/iio/adc/at91-sama5d2_adc.h>
37 
38 struct at91_adc_reg_layout {
39 /* Control Register */
40 	u16				CR;
41 /* Software Reset */
42 #define	AT91_SAMA5D2_CR_SWRST		BIT(0)
43 /* Start Conversion */
44 #define	AT91_SAMA5D2_CR_START		BIT(1)
45 /* Touchscreen Calibration */
46 #define	AT91_SAMA5D2_CR_TSCALIB		BIT(2)
47 /* Comparison Restart */
48 #define	AT91_SAMA5D2_CR_CMPRST		BIT(4)
49 
50 /* Mode Register */
51 	u16				MR;
52 /* Trigger Selection */
53 #define	AT91_SAMA5D2_MR_TRGSEL(v)	((v) << 1)
54 /* ADTRG */
55 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG0	0
56 /* TIOA0 */
57 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG1	1
58 /* TIOA1 */
59 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG2	2
60 /* TIOA2 */
61 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG3	3
62 /* PWM event line 0 */
63 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG4	4
64 /* PWM event line 1 */
65 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG5	5
66 /* TIOA3 */
67 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG6	6
68 /* RTCOUT0 */
69 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG7	7
70 /* Sleep Mode */
71 #define	AT91_SAMA5D2_MR_SLEEP		BIT(5)
72 /* Fast Wake Up */
73 #define	AT91_SAMA5D2_MR_FWUP		BIT(6)
74 /* Prescaler Rate Selection */
75 #define	AT91_SAMA5D2_MR_PRESCAL(v)	((v) << AT91_SAMA5D2_MR_PRESCAL_OFFSET)
76 #define	AT91_SAMA5D2_MR_PRESCAL_OFFSET	8
77 #define	AT91_SAMA5D2_MR_PRESCAL_MAX	0xff
78 #define AT91_SAMA5D2_MR_PRESCAL_MASK	GENMASK(15, 8)
79 /* Startup Time */
80 #define	AT91_SAMA5D2_MR_STARTUP(v)	((v) << 16)
81 #define AT91_SAMA5D2_MR_STARTUP_MASK	GENMASK(19, 16)
82 /* Minimum startup time for temperature sensor */
83 #define AT91_SAMA5D2_MR_STARTUP_TS_MIN	(50)
84 /* Analog Change */
85 #define	AT91_SAMA5D2_MR_ANACH		BIT(23)
86 /* Tracking Time */
87 #define	AT91_SAMA5D2_MR_TRACKTIM(v)	((v) << 24)
88 #define	AT91_SAMA5D2_MR_TRACKTIM_TS	6
89 #define	AT91_SAMA5D2_MR_TRACKTIM_MAX	0xf
90 /* Transfer Time */
91 #define	AT91_SAMA5D2_MR_TRANSFER(v)	((v) << 28)
92 #define	AT91_SAMA5D2_MR_TRANSFER_MAX	0x3
93 /* Use Sequence Enable */
94 #define	AT91_SAMA5D2_MR_USEQ		BIT(31)
95 
96 /* Channel Sequence Register 1 */
97 	u16				SEQR1;
98 /* Channel Sequence Register 2 */
99 	u16				SEQR2;
100 /* Channel Enable Register */
101 	u16				CHER;
102 /* Channel Disable Register */
103 	u16				CHDR;
104 /* Channel Status Register */
105 	u16				CHSR;
106 /* Last Converted Data Register */
107 	u16				LCDR;
108 /* Interrupt Enable Register */
109 	u16				IER;
110 /* Interrupt Enable Register - TS X measurement ready */
111 #define AT91_SAMA5D2_IER_XRDY   BIT(20)
112 /* Interrupt Enable Register - TS Y measurement ready */
113 #define AT91_SAMA5D2_IER_YRDY   BIT(21)
114 /* Interrupt Enable Register - TS pressure measurement ready */
115 #define AT91_SAMA5D2_IER_PRDY   BIT(22)
116 /* Interrupt Enable Register - Data ready */
117 #define AT91_SAMA5D2_IER_DRDY   BIT(24)
118 /* Interrupt Enable Register - general overrun error */
119 #define AT91_SAMA5D2_IER_GOVRE BIT(25)
120 /* Interrupt Enable Register - Pen detect */
121 #define AT91_SAMA5D2_IER_PEN    BIT(29)
122 /* Interrupt Enable Register - No pen detect */
123 #define AT91_SAMA5D2_IER_NOPEN  BIT(30)
124 
125 /* Interrupt Disable Register */
126 	u16				IDR;
127 /* Interrupt Mask Register */
128 	u16				IMR;
129 /* Interrupt Status Register */
130 	u16				ISR;
131 /* End of Conversion Interrupt Enable Register */
132 	u16				EOC_IER;
133 /* End of Conversion Interrupt Disable Register */
134 	u16				EOC_IDR;
135 /* End of Conversion Interrupt Mask Register */
136 	u16				EOC_IMR;
137 /* End of Conversion Interrupt Status Register */
138 	u16				EOC_ISR;
139 /* Interrupt Status Register - Pen touching sense status */
140 #define AT91_SAMA5D2_ISR_PENS   BIT(31)
141 /* Last Channel Trigger Mode Register */
142 	u16				LCTMR;
143 /* Last Channel Compare Window Register */
144 	u16				LCCWR;
145 /* Overrun Status Register */
146 	u16				OVER;
147 /* Extended Mode Register */
148 	u16				EMR;
149 /* Extended Mode Register - Oversampling rate */
150 #define AT91_SAMA5D2_EMR_OSR(V, M)		(((V) << 16) & (M))
151 #define AT91_SAMA5D2_EMR_OSR_1SAMPLES		0
152 #define AT91_SAMA5D2_EMR_OSR_4SAMPLES		1
153 #define AT91_SAMA5D2_EMR_OSR_16SAMPLES		2
154 #define AT91_SAMA5D2_EMR_OSR_64SAMPLES		3
155 #define AT91_SAMA5D2_EMR_OSR_256SAMPLES		4
156 
157 /* Extended Mode Register - TRACKX */
158 #define AT91_SAMA5D2_TRACKX_MASK		GENMASK(23, 22)
159 #define AT91_SAMA5D2_TRACKX(x)			(((x) << 22) & \
160 						 AT91_SAMA5D2_TRACKX_MASK)
161 /* TRACKX for temperature sensor. */
162 #define AT91_SAMA5D2_TRACKX_TS			(1)
163 
164 /* Extended Mode Register - Averaging on single trigger event */
165 #define AT91_SAMA5D2_EMR_ASTE(V)		((V) << 20)
166 
167 /* Compare Window Register */
168 	u16				CWR;
169 /* Channel Gain Register */
170 	u16				CGR;
171 /* Channel Offset Register */
172 	u16				COR;
173 /* Channel Offset Register differential offset - constant, not a register */
174 	u16				COR_diff_offset;
175 /* Analog Control Register */
176 	u16				ACR;
177 /* Analog Control Register - Pen detect sensitivity mask */
178 #define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
179 /* Analog Control Register - Source last channel */
180 #define AT91_SAMA5D2_ACR_SRCLCH		BIT(16)
181 
182 /* Touchscreen Mode Register */
183 	u16				TSMR;
184 /* Touchscreen Mode Register - No touch mode */
185 #define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
186 /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
187 #define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_NO_PRESS 1
188 /* Touchscreen Mode Register - 4 wire screen, pressure measurement */
189 #define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS    2
190 /* Touchscreen Mode Register - 5 wire screen */
191 #define AT91_SAMA5D2_TSMR_TSMODE_5WIRE          3
192 /* Touchscreen Mode Register - Average samples mask */
193 #define AT91_SAMA5D2_TSMR_TSAV_MASK             GENMASK(5, 4)
194 /* Touchscreen Mode Register - Average samples */
195 #define AT91_SAMA5D2_TSMR_TSAV(x)               ((x) << 4)
196 /* Touchscreen Mode Register - Touch/trigger frequency ratio mask */
197 #define AT91_SAMA5D2_TSMR_TSFREQ_MASK           GENMASK(11, 8)
198 /* Touchscreen Mode Register - Touch/trigger frequency ratio */
199 #define AT91_SAMA5D2_TSMR_TSFREQ(x)             ((x) << 8)
200 /* Touchscreen Mode Register - Pen Debounce Time mask */
201 #define AT91_SAMA5D2_TSMR_PENDBC_MASK           GENMASK(31, 28)
202 /* Touchscreen Mode Register - Pen Debounce Time */
203 #define AT91_SAMA5D2_TSMR_PENDBC(x)            ((x) << 28)
204 /* Touchscreen Mode Register - No DMA for touch measurements */
205 #define AT91_SAMA5D2_TSMR_NOTSDMA               BIT(22)
206 /* Touchscreen Mode Register - Disable pen detection */
207 #define AT91_SAMA5D2_TSMR_PENDET_DIS            (0 << 24)
208 /* Touchscreen Mode Register - Enable pen detection */
209 #define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
210 
211 /* Touchscreen X Position Register */
212 	u16				XPOSR;
213 /* Touchscreen Y Position Register */
214 	u16				YPOSR;
215 /* Touchscreen Pressure Register */
216 	u16				PRESSR;
217 /* Trigger Register */
218 	u16				TRGR;
219 /* Mask for TRGMOD field of TRGR register */
220 #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
221 /* No trigger, only software trigger can start conversions */
222 #define AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER 0
223 /* Trigger Mode external trigger rising edge */
224 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE 1
225 /* Trigger Mode external trigger falling edge */
226 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL 2
227 /* Trigger Mode external trigger any edge */
228 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY 3
229 /* Trigger Mode internal periodic */
230 #define AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC 5
231 /* Trigger Mode - trigger period mask */
232 #define AT91_SAMA5D2_TRGR_TRGPER_MASK           GENMASK(31, 16)
233 /* Trigger Mode - trigger period */
234 #define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
235 
236 /* Correction Select Register */
237 	u16				COSR;
238 /* Correction Value Register */
239 	u16				CVR;
240 /* Channel Error Correction Register */
241 	u16				CECR;
242 /* Write Protection Mode Register */
243 	u16				WPMR;
244 /* Write Protection Status Register */
245 	u16				WPSR;
246 /* Version Register */
247 	u16				VERSION;
248 /* Temperature Sensor Mode Register */
249 	u16				TEMPMR;
250 /* Temperature Sensor Mode - Temperature sensor on */
251 #define AT91_SAMA5D2_TEMPMR_TEMPON	BIT(0)
252 };
253 
254 static const struct at91_adc_reg_layout sama5d2_layout = {
255 	.CR =			0x00,
256 	.MR =			0x04,
257 	.SEQR1 =		0x08,
258 	.SEQR2 =		0x0c,
259 	.CHER =			0x10,
260 	.CHDR =			0x14,
261 	.CHSR =			0x18,
262 	.LCDR =			0x20,
263 	.IER =			0x24,
264 	.IDR =			0x28,
265 	.IMR =			0x2c,
266 	.ISR =			0x30,
267 	.LCTMR =		0x34,
268 	.LCCWR =		0x38,
269 	.OVER =			0x3c,
270 	.EMR =			0x40,
271 	.CWR =			0x44,
272 	.CGR =			0x48,
273 	.COR =			0x4c,
274 	.COR_diff_offset =	16,
275 	.ACR =			0x94,
276 	.TSMR =			0xb0,
277 	.XPOSR =		0xb4,
278 	.YPOSR =		0xb8,
279 	.PRESSR =		0xbc,
280 	.TRGR =			0xc0,
281 	.COSR =			0xd0,
282 	.CVR =			0xd4,
283 	.CECR =			0xd8,
284 	.WPMR =			0xe4,
285 	.WPSR =			0xe8,
286 	.VERSION =		0xfc,
287 };
288 
289 static const struct at91_adc_reg_layout sama7g5_layout = {
290 	.CR =			0x00,
291 	.MR =			0x04,
292 	.SEQR1 =		0x08,
293 	.SEQR2 =		0x0c,
294 	.CHER =			0x10,
295 	.CHDR =			0x14,
296 	.CHSR =			0x18,
297 	.LCDR =			0x20,
298 	.IER =			0x24,
299 	.IDR =			0x28,
300 	.IMR =			0x2c,
301 	.ISR =			0x30,
302 	.EOC_IER =		0x34,
303 	.EOC_IDR =		0x38,
304 	.EOC_IMR =		0x3c,
305 	.EOC_ISR =		0x40,
306 	.TEMPMR =		0x44,
307 	.OVER =			0x4c,
308 	.EMR =			0x50,
309 	.CWR =			0x54,
310 	.COR =			0x5c,
311 	.COR_diff_offset =	0,
312 	.ACR =			0xe0,
313 	.TRGR =			0x100,
314 	.COSR =			0x104,
315 	.CVR =			0x108,
316 	.CECR =			0x10c,
317 	.WPMR =			0x118,
318 	.WPSR =			0x11c,
319 	.VERSION =		0x130,
320 };
321 
322 #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
323 #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
324 
325 #define AT91_SAMA5D2_XYZ_MASK		GENMASK(11, 0)
326 
327 #define AT91_SAMA5D2_MAX_POS_BITS			12
328 
329 #define AT91_HWFIFO_MAX_SIZE_STR	"128"
330 #define AT91_HWFIFO_MAX_SIZE		128
331 
332 #define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)			\
333 	{								\
334 		.type = IIO_VOLTAGE,					\
335 		.channel = num,						\
336 		.address = addr,					\
337 		.scan_index = index,					\
338 		.scan_type = {						\
339 			.sign = 'u',					\
340 			.realbits = 14,					\
341 			.storagebits = 16,				\
342 		},							\
343 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
344 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
345 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
346 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
347 		.info_mask_shared_by_all_available =			\
348 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
349 		.datasheet_name = "CH"#num,				\
350 		.indexed = 1,						\
351 	}
352 
353 #define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)			\
354 	{								\
355 		.type = IIO_VOLTAGE,					\
356 		.differential = 1,					\
357 		.channel = num,						\
358 		.channel2 = num2,					\
359 		.address = addr,					\
360 		.scan_index = index,					\
361 		.scan_type = {						\
362 			.sign = 's',					\
363 			.realbits = 14,					\
364 			.storagebits = 16,				\
365 		},							\
366 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
367 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
368 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
369 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
370 		.info_mask_shared_by_all_available =			\
371 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
372 		.datasheet_name = "CH"#num"-CH"#num2,			\
373 		.indexed = 1,						\
374 	}
375 
376 #define AT91_SAMA5D2_CHAN_TOUCH(num, name, mod)				\
377 	{								\
378 		.type = IIO_POSITIONRELATIVE,				\
379 		.modified = 1,						\
380 		.channel = num,						\
381 		.channel2 = mod,					\
382 		.scan_index = num,					\
383 		.scan_type = {						\
384 			.sign = 'u',					\
385 			.realbits = 12,					\
386 			.storagebits = 16,				\
387 		},							\
388 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
389 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
390 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
391 		.info_mask_shared_by_all_available =			\
392 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
393 		.datasheet_name = name,					\
394 	}
395 #define AT91_SAMA5D2_CHAN_PRESSURE(num, name)				\
396 	{								\
397 		.type = IIO_PRESSURE,					\
398 		.channel = num,						\
399 		.scan_index = num,					\
400 		.scan_type = {						\
401 			.sign = 'u',					\
402 			.realbits = 12,					\
403 			.storagebits = 16,				\
404 		},							\
405 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
406 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
407 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
408 		.info_mask_shared_by_all_available =			\
409 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
410 		.datasheet_name = name,					\
411 	}
412 
413 #define AT91_SAMA5D2_CHAN_TEMP(num, name, addr)				\
414 	{								\
415 		.type = IIO_TEMP,					\
416 		.channel = num,						\
417 		.address =  addr,					\
418 		.scan_index = num,					\
419 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),	\
420 		.info_mask_shared_by_all =				\
421 				BIT(IIO_CHAN_INFO_PROCESSED) |		\
422 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
423 		.info_mask_shared_by_all_available =			\
424 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
425 		.datasheet_name = name,					\
426 	}
427 
428 #define at91_adc_readl(st, reg)						\
429 	readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
430 #define at91_adc_read_chan(st, reg)					\
431 	readl_relaxed((st)->base + reg)
432 #define at91_adc_writel(st, reg, val)					\
433 	writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg)
434 
435 /**
436  * struct at91_adc_platform - at91-sama5d2 platform information struct
437  * @layout:		pointer to the reg layout struct
438  * @adc_channels:	pointer to an array of channels for registering in
439  *			the iio subsystem
440  * @nr_channels:	number of physical channels available
441  * @touch_chan_x:	index of the touchscreen X channel
442  * @touch_chan_y:	index of the touchscreen Y channel
443  * @touch_chan_p:	index of the touchscreen P channel
444  * @max_channels:	number of total channels
445  * @max_index:		highest channel index (highest index may be higher
446  *			than the total channel number)
447  * @hw_trig_cnt:	number of possible hardware triggers
448  * @osr_mask:		oversampling ratio bitmask on EMR register
449  * @oversampling_avail:	available oversampling values
450  * @oversampling_avail_no: number of available oversampling values
451  * @chan_realbits:	realbits for registered channels
452  * @temp_chan:		temperature channel index
453  * @temp_sensor:	temperature sensor supported
454  */
455 struct at91_adc_platform {
456 	const struct at91_adc_reg_layout	*layout;
457 	const struct iio_chan_spec		(*adc_channels)[];
458 	unsigned int				nr_channels;
459 	unsigned int				touch_chan_x;
460 	unsigned int				touch_chan_y;
461 	unsigned int				touch_chan_p;
462 	unsigned int				max_channels;
463 	unsigned int				max_index;
464 	unsigned int				hw_trig_cnt;
465 	unsigned int				osr_mask;
466 	unsigned int				oversampling_avail[5];
467 	unsigned int				oversampling_avail_no;
468 	unsigned int				chan_realbits;
469 	unsigned int				temp_chan;
470 	bool					temp_sensor;
471 };
472 
473 /**
474  * struct at91_adc_temp_sensor_clb - at91-sama5d2 temperature sensor
475  * calibration data structure
476  * @p1: P1 calibration temperature
477  * @p4: P4 calibration voltage
478  * @p6: P6 calibration voltage
479  */
480 struct at91_adc_temp_sensor_clb {
481 	u32 p1;
482 	u32 p4;
483 	u32 p6;
484 };
485 
486 /**
487  * enum at91_adc_ts_clb_idx - calibration indexes in NVMEM buffer
488  * @AT91_ADC_TS_CLB_IDX_P1: index for P1
489  * @AT91_ADC_TS_CLB_IDX_P4: index for P4
490  * @AT91_ADC_TS_CLB_IDX_P6: index for P6
491  * @AT91_ADC_TS_CLB_IDX_MAX: max index for temperature calibration packet in OTP
492  */
493 enum at91_adc_ts_clb_idx {
494 	AT91_ADC_TS_CLB_IDX_P1 = 2,
495 	AT91_ADC_TS_CLB_IDX_P4 = 5,
496 	AT91_ADC_TS_CLB_IDX_P6 = 7,
497 	AT91_ADC_TS_CLB_IDX_MAX = 19,
498 };
499 
500 /* Temperature sensor calibration - Vtemp voltage sensitivity to temperature. */
501 #define AT91_ADC_TS_VTEMP_DT		(2080U)
502 
503 /**
504  * struct at91_adc_soc_info - at91-sama5d2 soc information struct
505  * @startup_time:	device startup time
506  * @min_sample_rate:	minimum sample rate in Hz
507  * @max_sample_rate:	maximum sample rate in Hz
508  * @platform:		pointer to the platform structure
509  * @temp_sensor_clb:	temperature sensor calibration data structure
510  */
511 struct at91_adc_soc_info {
512 	unsigned			startup_time;
513 	unsigned			min_sample_rate;
514 	unsigned			max_sample_rate;
515 	const struct at91_adc_platform	*platform;
516 	struct at91_adc_temp_sensor_clb	temp_sensor_clb;
517 };
518 
519 struct at91_adc_trigger {
520 	char				*name;
521 	unsigned int			trgmod_value;
522 	unsigned int			edge_type;
523 	bool				hw_trig;
524 };
525 
526 /**
527  * struct at91_adc_dma - at91-sama5d2 dma information struct
528  * @dma_chan:		the dma channel acquired
529  * @rx_buf:		dma coherent allocated area
530  * @rx_dma_buf:		dma handler for the buffer
531  * @phys_addr:		physical address of the ADC base register
532  * @buf_idx:		index inside the dma buffer where reading was last done
533  * @rx_buf_sz:		size of buffer used by DMA operation
534  * @watermark:		number of conversions to copy before DMA triggers irq
535  * @dma_ts:		hold the start timestamp of dma operation
536  */
537 struct at91_adc_dma {
538 	struct dma_chan			*dma_chan;
539 	u8				*rx_buf;
540 	dma_addr_t			rx_dma_buf;
541 	phys_addr_t			phys_addr;
542 	int				buf_idx;
543 	int				rx_buf_sz;
544 	int				watermark;
545 	s64				dma_ts;
546 };
547 
548 /**
549  * struct at91_adc_touch - at91-sama5d2 touchscreen information struct
550  * @sample_period_val:		the value for periodic trigger interval
551  * @touching:			is the pen touching the screen or not
552  * @x_pos:			temporary placeholder for pressure computation
553  * @channels_bitmask:		bitmask with the touchscreen channels enabled
554  * @workq:			workqueue for buffer data pushing
555  */
556 struct at91_adc_touch {
557 	u16				sample_period_val;
558 	bool				touching;
559 	u16				x_pos;
560 	unsigned long			channels_bitmask;
561 	struct work_struct		workq;
562 };
563 
564 /**
565  * struct at91_adc_temp - at91-sama5d2 temperature information structure
566  * @sample_period_val:	sample period value
567  * @saved_sample_rate:	saved sample rate
568  * @saved_oversampling:	saved oversampling
569  */
570 struct at91_adc_temp {
571 	u16				sample_period_val;
572 	u16				saved_sample_rate;
573 	u16				saved_oversampling;
574 };
575 
576 /*
577  * Buffer size requirements:
578  * No channels * bytes_per_channel(2) + timestamp bytes (8)
579  * Divided by 2 because we need half words.
580  * We assume 32 channels for now, has to be increased if needed.
581  * Nobody minds a buffer being too big.
582  */
583 #define AT91_BUFFER_MAX_HWORDS ((32 * 2 + 8) / 2)
584 
585 struct at91_adc_state {
586 	void __iomem			*base;
587 	int				irq;
588 	struct clk			*per_clk;
589 	struct regulator		*reg;
590 	struct regulator		*vref;
591 	int				vref_uv;
592 	unsigned int			current_sample_rate;
593 	struct iio_trigger		*trig;
594 	const struct at91_adc_trigger	*selected_trig;
595 	const struct iio_chan_spec	*chan;
596 	bool				conversion_done;
597 	u32				conversion_value;
598 	unsigned int			oversampling_ratio;
599 	struct at91_adc_soc_info	soc_info;
600 	wait_queue_head_t		wq_data_available;
601 	struct at91_adc_dma		dma_st;
602 	struct at91_adc_touch		touch_st;
603 	struct at91_adc_temp		temp_st;
604 	struct iio_dev			*indio_dev;
605 	struct device			*dev;
606 	/* Ensure naturally aligned timestamp */
607 	u16				buffer[AT91_BUFFER_MAX_HWORDS] __aligned(8);
608 	/*
609 	 * lock to prevent concurrent 'single conversion' requests through
610 	 * sysfs.
611 	 */
612 	struct mutex			lock;
613 };
614 
615 static const struct at91_adc_trigger at91_adc_trigger_list[] = {
616 	{
617 		.name = "external_rising",
618 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE,
619 		.edge_type = IRQ_TYPE_EDGE_RISING,
620 		.hw_trig = true,
621 	},
622 	{
623 		.name = "external_falling",
624 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL,
625 		.edge_type = IRQ_TYPE_EDGE_FALLING,
626 		.hw_trig = true,
627 	},
628 	{
629 		.name = "external_any",
630 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY,
631 		.edge_type = IRQ_TYPE_EDGE_BOTH,
632 		.hw_trig = true,
633 	},
634 	{
635 		.name = "software",
636 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER,
637 		.edge_type = IRQ_TYPE_NONE,
638 		.hw_trig = false,
639 	},
640 };
641 
642 static const struct iio_chan_spec at91_sama5d2_adc_channels[] = {
643 	AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50),
644 	AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54),
645 	AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58),
646 	AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c),
647 	AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60),
648 	AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64),
649 	AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68),
650 	AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c),
651 	AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70),
652 	AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74),
653 	AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78),
654 	AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
655 	/* original ABI has the differential channels with a gap in between */
656 	AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
657 	AT91_SAMA5D2_CHAN_DIFF(14, 2, 3, 0x58),
658 	AT91_SAMA5D2_CHAN_DIFF(16, 4, 5, 0x60),
659 	AT91_SAMA5D2_CHAN_DIFF(18, 6, 7, 0x68),
660 	AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x70),
661 	AT91_SAMA5D2_CHAN_DIFF(22, 10, 11, 0x78),
662 	IIO_CHAN_SOFT_TIMESTAMP(23),
663 	AT91_SAMA5D2_CHAN_TOUCH(24, "x", IIO_MOD_X),
664 	AT91_SAMA5D2_CHAN_TOUCH(25, "y", IIO_MOD_Y),
665 	AT91_SAMA5D2_CHAN_PRESSURE(26, "pressure"),
666 };
667 
668 static const struct iio_chan_spec at91_sama7g5_adc_channels[] = {
669 	AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x60),
670 	AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x64),
671 	AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x68),
672 	AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x6c),
673 	AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x70),
674 	AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x74),
675 	AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x78),
676 	AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x7c),
677 	AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x80),
678 	AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x84),
679 	AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x88),
680 	AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x8c),
681 	AT91_SAMA5D2_CHAN_SINGLE(12, 12, 0x90),
682 	AT91_SAMA5D2_CHAN_SINGLE(13, 13, 0x94),
683 	AT91_SAMA5D2_CHAN_SINGLE(14, 14, 0x98),
684 	AT91_SAMA5D2_CHAN_SINGLE(15, 15, 0x9c),
685 	AT91_SAMA5D2_CHAN_DIFF(16, 0, 1, 0x60),
686 	AT91_SAMA5D2_CHAN_DIFF(17, 2, 3, 0x68),
687 	AT91_SAMA5D2_CHAN_DIFF(18, 4, 5, 0x70),
688 	AT91_SAMA5D2_CHAN_DIFF(19, 6, 7, 0x78),
689 	AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x80),
690 	AT91_SAMA5D2_CHAN_DIFF(21, 10, 11, 0x88),
691 	AT91_SAMA5D2_CHAN_DIFF(22, 12, 13, 0x90),
692 	AT91_SAMA5D2_CHAN_DIFF(23, 14, 15, 0x98),
693 	IIO_CHAN_SOFT_TIMESTAMP(24),
694 	AT91_SAMA5D2_CHAN_TEMP(AT91_SAMA7G5_ADC_TEMP_CHANNEL, "temp", 0xdc),
695 };
696 
697 static const struct at91_adc_platform sama5d2_platform = {
698 	.layout = &sama5d2_layout,
699 	.adc_channels = &at91_sama5d2_adc_channels,
700 #define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
701 #define AT91_SAMA5D2_DIFF_CHAN_CNT 6
702 	.nr_channels = AT91_SAMA5D2_SINGLE_CHAN_CNT +
703 		       AT91_SAMA5D2_DIFF_CHAN_CNT,
704 #define AT91_SAMA5D2_TOUCH_X_CHAN_IDX	(AT91_SAMA5D2_SINGLE_CHAN_CNT + \
705 					AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
706 	.touch_chan_x = AT91_SAMA5D2_TOUCH_X_CHAN_IDX,
707 #define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX	(AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
708 	.touch_chan_y = AT91_SAMA5D2_TOUCH_Y_CHAN_IDX,
709 #define AT91_SAMA5D2_TOUCH_P_CHAN_IDX	(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
710 	.touch_chan_p = AT91_SAMA5D2_TOUCH_P_CHAN_IDX,
711 #define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
712 	.max_channels = ARRAY_SIZE(at91_sama5d2_adc_channels),
713 	.max_index = AT91_SAMA5D2_MAX_CHAN_IDX,
714 #define AT91_SAMA5D2_HW_TRIG_CNT	3
715 	.hw_trig_cnt = AT91_SAMA5D2_HW_TRIG_CNT,
716 	.osr_mask = GENMASK(17, 16),
717 	.oversampling_avail = { 1, 4, 16, },
718 	.oversampling_avail_no = 3,
719 	.chan_realbits = 14,
720 };
721 
722 static const struct at91_adc_platform sama7g5_platform = {
723 	.layout = &sama7g5_layout,
724 	.adc_channels = &at91_sama7g5_adc_channels,
725 #define AT91_SAMA7G5_SINGLE_CHAN_CNT	16
726 #define AT91_SAMA7G5_DIFF_CHAN_CNT	8
727 #define AT91_SAMA7G5_TEMP_CHAN_CNT	1
728 	.nr_channels = AT91_SAMA7G5_SINGLE_CHAN_CNT +
729 		       AT91_SAMA7G5_DIFF_CHAN_CNT +
730 		       AT91_SAMA7G5_TEMP_CHAN_CNT,
731 #define AT91_SAMA7G5_MAX_CHAN_IDX	(AT91_SAMA7G5_SINGLE_CHAN_CNT + \
732 					AT91_SAMA7G5_DIFF_CHAN_CNT + \
733 					AT91_SAMA7G5_TEMP_CHAN_CNT)
734 	.max_channels = ARRAY_SIZE(at91_sama7g5_adc_channels),
735 	.max_index = AT91_SAMA7G5_MAX_CHAN_IDX,
736 #define AT91_SAMA7G5_HW_TRIG_CNT	3
737 	.hw_trig_cnt = AT91_SAMA7G5_HW_TRIG_CNT,
738 	.osr_mask = GENMASK(18, 16),
739 	.oversampling_avail = { 1, 4, 16, 64, 256, },
740 	.oversampling_avail_no = 5,
741 	.chan_realbits = 16,
742 	.temp_sensor = true,
743 	.temp_chan = AT91_SAMA7G5_ADC_TEMP_CHANNEL,
744 };
745 
746 static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
747 {
748 	int i;
749 
750 	for (i = 0; i < indio_dev->num_channels; i++) {
751 		if (indio_dev->channels[i].scan_index == chan)
752 			return i;
753 	}
754 	return -EINVAL;
755 }
756 
757 static inline struct iio_chan_spec const *
758 at91_adc_chan_get(struct iio_dev *indio_dev, int chan)
759 {
760 	int index = at91_adc_chan_xlate(indio_dev, chan);
761 
762 	if (index < 0)
763 		return NULL;
764 	return indio_dev->channels + index;
765 }
766 
767 static inline int at91_adc_fwnode_xlate(struct iio_dev *indio_dev,
768 					const struct fwnode_reference_args *iiospec)
769 {
770 	return at91_adc_chan_xlate(indio_dev, iiospec->args[0]);
771 }
772 
773 static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev)
774 {
775 	u32 mask = 0;
776 	u8 bit;
777 	struct at91_adc_state *st = iio_priv(indio_dev);
778 
779 	for_each_set_bit(bit, indio_dev->active_scan_mask,
780 			 indio_dev->num_channels) {
781 		struct iio_chan_spec const *chan =
782 			 at91_adc_chan_get(indio_dev, bit);
783 		mask |= BIT(chan->channel);
784 	}
785 
786 	return mask & GENMASK(st->soc_info.platform->nr_channels, 0);
787 }
788 
789 static void at91_adc_cor(struct at91_adc_state *st,
790 			 struct iio_chan_spec const *chan)
791 {
792 	u32 cor, cur_cor;
793 
794 	cor = BIT(chan->channel) | BIT(chan->channel2);
795 
796 	cur_cor = at91_adc_readl(st, COR);
797 	cor <<= st->soc_info.platform->layout->COR_diff_offset;
798 	if (chan->differential)
799 		at91_adc_writel(st, COR, cur_cor | cor);
800 	else
801 		at91_adc_writel(st, COR, cur_cor & ~cor);
802 }
803 
804 static void at91_adc_irq_status(struct at91_adc_state *st, u32 *status,
805 				u32 *eoc)
806 {
807 	*status = at91_adc_readl(st, ISR);
808 	if (st->soc_info.platform->layout->EOC_ISR)
809 		*eoc = at91_adc_readl(st, EOC_ISR);
810 	else
811 		*eoc = *status;
812 }
813 
814 static void at91_adc_irq_mask(struct at91_adc_state *st, u32 *status, u32 *eoc)
815 {
816 	*status = at91_adc_readl(st, IMR);
817 	if (st->soc_info.platform->layout->EOC_IMR)
818 		*eoc = at91_adc_readl(st, EOC_IMR);
819 	else
820 		*eoc = *status;
821 }
822 
823 static void at91_adc_eoc_dis(struct at91_adc_state *st, unsigned int channel)
824 {
825 	/*
826 	 * On some products having the EOC bits in a separate register,
827 	 * errata recommends not writing this register (EOC_IDR).
828 	 * On products having the EOC bits in the IDR register, it's fine to write it.
829 	 */
830 	if (!st->soc_info.platform->layout->EOC_IDR)
831 		at91_adc_writel(st, IDR, BIT(channel));
832 }
833 
834 static void at91_adc_eoc_ena(struct at91_adc_state *st, unsigned int channel)
835 {
836 	if (!st->soc_info.platform->layout->EOC_IDR)
837 		at91_adc_writel(st, IER, BIT(channel));
838 	else
839 		at91_adc_writel(st, EOC_IER, BIT(channel));
840 }
841 
842 static int at91_adc_config_emr(struct at91_adc_state *st,
843 			       u32 oversampling_ratio, u32 trackx)
844 {
845 	/* configure the extended mode register */
846 	unsigned int emr, osr;
847 	unsigned int osr_mask = st->soc_info.platform->osr_mask;
848 	int i, ret;
849 
850 	/* Check against supported oversampling values. */
851 	for (i = 0; i < st->soc_info.platform->oversampling_avail_no; i++) {
852 		if (oversampling_ratio == st->soc_info.platform->oversampling_avail[i])
853 			break;
854 	}
855 	if (i == st->soc_info.platform->oversampling_avail_no)
856 		return -EINVAL;
857 
858 	/* select oversampling ratio from configuration */
859 	switch (oversampling_ratio) {
860 	case 1:
861 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES,
862 					   osr_mask);
863 		break;
864 	case 4:
865 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES,
866 					   osr_mask);
867 		break;
868 	case 16:
869 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES,
870 					   osr_mask);
871 		break;
872 	case 64:
873 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_64SAMPLES,
874 					   osr_mask);
875 		break;
876 	case 256:
877 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_256SAMPLES,
878 					   osr_mask);
879 		break;
880 	}
881 
882 	ret = pm_runtime_resume_and_get(st->dev);
883 	if (ret < 0)
884 		return ret;
885 
886 	emr = at91_adc_readl(st, EMR);
887 	/* select oversampling per single trigger event */
888 	emr |= AT91_SAMA5D2_EMR_ASTE(1);
889 	/* delete leftover content if it's the case */
890 	emr &= ~(osr_mask | AT91_SAMA5D2_TRACKX_MASK);
891 	/* Update osr and trackx. */
892 	emr |= osr | AT91_SAMA5D2_TRACKX(trackx);
893 	at91_adc_writel(st, EMR, emr);
894 
895 	pm_runtime_mark_last_busy(st->dev);
896 	pm_runtime_put_autosuspend(st->dev);
897 
898 	st->oversampling_ratio = oversampling_ratio;
899 
900 	return 0;
901 }
902 
903 static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val)
904 {
905 	int nbits, diff;
906 
907 	if (st->oversampling_ratio == 1)
908 		nbits = 12;
909 	else if (st->oversampling_ratio == 4)
910 		nbits = 13;
911 	else if (st->oversampling_ratio == 16)
912 		nbits = 14;
913 	else if (st->oversampling_ratio == 64)
914 		nbits = 15;
915 	else if (st->oversampling_ratio == 256)
916 		nbits = 16;
917 	else
918 		/* Should not happen. */
919 		return -EINVAL;
920 
921 	/*
922 	 * We have nbits of real data and channel is registered as
923 	 * st->soc_info.platform->chan_realbits, so shift left diff bits.
924 	 */
925 	diff = st->soc_info.platform->chan_realbits - nbits;
926 	*val <<= diff;
927 
928 	return IIO_VAL_INT;
929 }
930 
931 static void at91_adc_adjust_val_osr_array(struct at91_adc_state *st, void *buf,
932 					  int len)
933 {
934 	int i = 0, val;
935 	u16 *buf_u16 = (u16 *) buf;
936 
937 	/*
938 	 * We are converting each two bytes (each sample).
939 	 * First convert the byte based array to u16, and convert each sample
940 	 * separately.
941 	 * Each value is two bytes in an array of chars, so to not shift
942 	 * more than we need, save the value separately.
943 	 * len is in bytes, so divide by two to get number of samples.
944 	 */
945 	while (i < len / 2) {
946 		val = buf_u16[i];
947 		at91_adc_adjust_val_osr(st, &val);
948 		buf_u16[i] = val;
949 		i++;
950 	}
951 }
952 
953 static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
954 {
955 	u32 clk_khz = st->current_sample_rate / 1000;
956 	int i = 0, ret;
957 	u16 pendbc;
958 	u32 tsmr, acr;
959 
960 	if (state) {
961 		ret = pm_runtime_resume_and_get(st->dev);
962 		if (ret < 0)
963 			return ret;
964 	} else {
965 		/* disabling touch IRQs and setting mode to no touch enabled */
966 		at91_adc_writel(st, IDR,
967 				AT91_SAMA5D2_IER_PEN | AT91_SAMA5D2_IER_NOPEN);
968 		at91_adc_writel(st, TSMR, 0);
969 
970 		pm_runtime_mark_last_busy(st->dev);
971 		pm_runtime_put_autosuspend(st->dev);
972 		return 0;
973 	}
974 	/*
975 	 * debounce time is in microseconds, we need it in milliseconds to
976 	 * multiply with kilohertz, so, divide by 1000, but after the multiply.
977 	 * round up to make sure pendbc is at least 1
978 	 */
979 	pendbc = round_up(AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US *
980 			  clk_khz / 1000, 1);
981 
982 	/* get the required exponent */
983 	while (pendbc >> i++)
984 		;
985 
986 	pendbc = i;
987 
988 	tsmr = AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS;
989 
990 	tsmr |= AT91_SAMA5D2_TSMR_TSAV(2) & AT91_SAMA5D2_TSMR_TSAV_MASK;
991 	tsmr |= AT91_SAMA5D2_TSMR_PENDBC(pendbc) &
992 		AT91_SAMA5D2_TSMR_PENDBC_MASK;
993 	tsmr |= AT91_SAMA5D2_TSMR_NOTSDMA;
994 	tsmr |= AT91_SAMA5D2_TSMR_PENDET_ENA;
995 	tsmr |= AT91_SAMA5D2_TSMR_TSFREQ(2) & AT91_SAMA5D2_TSMR_TSFREQ_MASK;
996 
997 	at91_adc_writel(st, TSMR, tsmr);
998 
999 	acr =  at91_adc_readl(st, ACR);
1000 	acr &= ~AT91_SAMA5D2_ACR_PENDETSENS_MASK;
1001 	acr |= 0x02 & AT91_SAMA5D2_ACR_PENDETSENS_MASK;
1002 	at91_adc_writel(st, ACR, acr);
1003 
1004 	/* Sample Period Time = (TRGPER + 1) / ADCClock */
1005 	st->touch_st.sample_period_val =
1006 				 round_up((AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US *
1007 				 clk_khz / 1000) - 1, 1);
1008 	/* enable pen detect IRQ */
1009 	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
1010 
1011 	return 0;
1012 }
1013 
1014 static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
1015 {
1016 	u32 val = 0;
1017 	u32 scale, result, pos;
1018 
1019 	/*
1020 	 * to obtain the actual position we must divide by scale
1021 	 * and multiply with max, where
1022 	 * max = 2^AT91_SAMA5D2_MAX_POS_BITS - 1
1023 	 */
1024 	/* first half of register is the x or y, second half is the scale */
1025 	if (reg == st->soc_info.platform->layout->XPOSR)
1026 		val = at91_adc_readl(st, XPOSR);
1027 	else if (reg == st->soc_info.platform->layout->YPOSR)
1028 		val = at91_adc_readl(st, YPOSR);
1029 
1030 	if (!val)
1031 		dev_dbg(&st->indio_dev->dev, "pos is 0\n");
1032 
1033 	pos = val & AT91_SAMA5D2_XYZ_MASK;
1034 	result = (pos << AT91_SAMA5D2_MAX_POS_BITS) - pos;
1035 	scale = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
1036 	if (scale == 0) {
1037 		dev_err(&st->indio_dev->dev, "scale is 0\n");
1038 		return 0;
1039 	}
1040 	result /= scale;
1041 
1042 	return result;
1043 }
1044 
1045 static u16 at91_adc_touch_x_pos(struct at91_adc_state *st)
1046 {
1047 	st->touch_st.x_pos = at91_adc_touch_pos(st, st->soc_info.platform->layout->XPOSR);
1048 	return st->touch_st.x_pos;
1049 }
1050 
1051 static u16 at91_adc_touch_y_pos(struct at91_adc_state *st)
1052 {
1053 	return at91_adc_touch_pos(st, st->soc_info.platform->layout->YPOSR);
1054 }
1055 
1056 static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
1057 {
1058 	u32 val;
1059 	u32 z1, z2;
1060 	u32 pres;
1061 	u32 rxp = 1;
1062 	u32 factor = 1000;
1063 
1064 	/* calculate the pressure */
1065 	val = at91_adc_readl(st, PRESSR);
1066 	z1 = val & AT91_SAMA5D2_XYZ_MASK;
1067 	z2 = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
1068 
1069 	if (z1 != 0)
1070 		pres = rxp * (st->touch_st.x_pos * factor / 1024) *
1071 			(z2 * factor / z1 - factor) /
1072 			factor;
1073 	else
1074 		pres = 0xFFFF;       /* no pen contact */
1075 
1076 	/*
1077 	 * The pressure from device grows down, minimum is 0xFFFF, maximum 0x0.
1078 	 * We compute it this way, but let's return it in the expected way,
1079 	 * growing from 0 to 0xFFFF.
1080 	 */
1081 	return 0xFFFF - pres;
1082 }
1083 
1084 static int at91_adc_read_position(struct at91_adc_state *st, int chan, u16 *val)
1085 {
1086 	*val = 0;
1087 	if (!st->touch_st.touching)
1088 		return -ENODATA;
1089 	if (chan == st->soc_info.platform->touch_chan_x)
1090 		*val = at91_adc_touch_x_pos(st);
1091 	else if (chan == st->soc_info.platform->touch_chan_y)
1092 		*val = at91_adc_touch_y_pos(st);
1093 	else
1094 		return -ENODATA;
1095 
1096 	return IIO_VAL_INT;
1097 }
1098 
1099 static int at91_adc_read_pressure(struct at91_adc_state *st, int chan, u16 *val)
1100 {
1101 	*val = 0;
1102 	if (!st->touch_st.touching)
1103 		return -ENODATA;
1104 	if (chan == st->soc_info.platform->touch_chan_p)
1105 		*val = at91_adc_touch_pressure(st);
1106 	else
1107 		return -ENODATA;
1108 
1109 	return IIO_VAL_INT;
1110 }
1111 
1112 static void at91_adc_configure_trigger_registers(struct at91_adc_state *st,
1113 						 bool state)
1114 {
1115 	u32 status = at91_adc_readl(st, TRGR);
1116 
1117 	/* clear TRGMOD */
1118 	status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK;
1119 
1120 	if (state)
1121 		status |= st->selected_trig->trgmod_value;
1122 
1123 	/* set/unset hw trigger */
1124 	at91_adc_writel(st, TRGR, status);
1125 }
1126 
1127 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
1128 {
1129 	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
1130 	struct at91_adc_state *st = iio_priv(indio);
1131 	int ret;
1132 
1133 	if (state) {
1134 		ret = pm_runtime_resume_and_get(st->dev);
1135 		if (ret < 0)
1136 			return ret;
1137 	}
1138 
1139 	at91_adc_configure_trigger_registers(st, state);
1140 
1141 	if (!state) {
1142 		pm_runtime_mark_last_busy(st->dev);
1143 		pm_runtime_put_autosuspend(st->dev);
1144 	}
1145 
1146 	return 0;
1147 }
1148 
1149 static void at91_adc_reenable_trigger(struct iio_trigger *trig)
1150 {
1151 	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
1152 	struct at91_adc_state *st = iio_priv(indio);
1153 
1154 	/* if we are using DMA, we must not reenable irq after each trigger */
1155 	if (st->dma_st.dma_chan)
1156 		return;
1157 
1158 	enable_irq(st->irq);
1159 
1160 	/* Needed to ACK the DRDY interruption */
1161 	at91_adc_readl(st, LCDR);
1162 }
1163 
1164 static const struct iio_trigger_ops at91_adc_trigger_ops = {
1165 	.set_trigger_state = &at91_adc_configure_trigger,
1166 	.reenable = &at91_adc_reenable_trigger,
1167 	.validate_device = iio_trigger_validate_own_device,
1168 };
1169 
1170 static int at91_adc_dma_size_done(struct at91_adc_state *st)
1171 {
1172 	struct dma_tx_state state;
1173 	enum dma_status status;
1174 	int i, size;
1175 
1176 	status = dmaengine_tx_status(st->dma_st.dma_chan,
1177 				     st->dma_st.dma_chan->cookie,
1178 				     &state);
1179 	if (status != DMA_IN_PROGRESS)
1180 		return 0;
1181 
1182 	/* Transferred length is size in bytes from end of buffer */
1183 	i = st->dma_st.rx_buf_sz - state.residue;
1184 
1185 	/* Return available bytes */
1186 	if (i >= st->dma_st.buf_idx)
1187 		size = i - st->dma_st.buf_idx;
1188 	else
1189 		size = st->dma_st.rx_buf_sz + i - st->dma_st.buf_idx;
1190 	return size;
1191 }
1192 
1193 static void at91_dma_buffer_done(void *data)
1194 {
1195 	struct iio_dev *indio_dev = data;
1196 
1197 	iio_trigger_poll_chained(indio_dev->trig);
1198 }
1199 
1200 static int at91_adc_dma_start(struct iio_dev *indio_dev)
1201 {
1202 	struct at91_adc_state *st = iio_priv(indio_dev);
1203 	struct dma_async_tx_descriptor *desc;
1204 	dma_cookie_t cookie;
1205 	int ret;
1206 	u8 bit;
1207 
1208 	if (!st->dma_st.dma_chan)
1209 		return 0;
1210 
1211 	/* we start a new DMA, so set buffer index to start */
1212 	st->dma_st.buf_idx = 0;
1213 
1214 	/*
1215 	 * compute buffer size w.r.t. watermark and enabled channels.
1216 	 * scan_bytes is aligned so we need an exact size for DMA
1217 	 */
1218 	st->dma_st.rx_buf_sz = 0;
1219 
1220 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1221 			 indio_dev->num_channels) {
1222 		struct iio_chan_spec const *chan =
1223 					 at91_adc_chan_get(indio_dev, bit);
1224 
1225 		if (!chan)
1226 			continue;
1227 
1228 		st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8;
1229 	}
1230 	st->dma_st.rx_buf_sz *= st->dma_st.watermark;
1231 
1232 	/* Prepare a DMA cyclic transaction */
1233 	desc = dmaengine_prep_dma_cyclic(st->dma_st.dma_chan,
1234 					 st->dma_st.rx_dma_buf,
1235 					 st->dma_st.rx_buf_sz,
1236 					 st->dma_st.rx_buf_sz / 2,
1237 					 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1238 
1239 	if (!desc) {
1240 		dev_err(&indio_dev->dev, "cannot prepare DMA cyclic\n");
1241 		return -EBUSY;
1242 	}
1243 
1244 	desc->callback = at91_dma_buffer_done;
1245 	desc->callback_param = indio_dev;
1246 
1247 	cookie = dmaengine_submit(desc);
1248 	ret = dma_submit_error(cookie);
1249 	if (ret) {
1250 		dev_err(&indio_dev->dev, "cannot submit DMA cyclic\n");
1251 		dmaengine_terminate_async(st->dma_st.dma_chan);
1252 		return ret;
1253 	}
1254 
1255 	/* enable general overrun error signaling */
1256 	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_GOVRE);
1257 	/* Issue pending DMA requests */
1258 	dma_async_issue_pending(st->dma_st.dma_chan);
1259 
1260 	/* consider current time as DMA start time for timestamps */
1261 	st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
1262 
1263 	dev_dbg(&indio_dev->dev, "DMA cyclic started\n");
1264 
1265 	return 0;
1266 }
1267 
1268 static bool at91_adc_buffer_check_use_irq(struct iio_dev *indio,
1269 					  struct at91_adc_state *st)
1270 {
1271 	/* if using DMA, we do not use our own IRQ (we use DMA-controller) */
1272 	if (st->dma_st.dma_chan)
1273 		return false;
1274 	/* if the trigger is not ours, then it has its own IRQ */
1275 	if (iio_trigger_validate_own_device(indio->trig, indio))
1276 		return false;
1277 	return true;
1278 }
1279 
1280 static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev)
1281 {
1282 	struct at91_adc_state *st = iio_priv(indio_dev);
1283 
1284 	return !!bitmap_subset(indio_dev->active_scan_mask,
1285 			       &st->touch_st.channels_bitmask,
1286 			       st->soc_info.platform->max_index + 1);
1287 }
1288 
1289 static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
1290 {
1291 	int ret;
1292 	u8 bit;
1293 	struct at91_adc_state *st = iio_priv(indio_dev);
1294 
1295 	/* check if we are enabling triggered buffer or the touchscreen */
1296 	if (at91_adc_current_chan_is_touch(indio_dev))
1297 		return at91_adc_configure_touch(st, true);
1298 
1299 	/* if we are not in triggered mode, we cannot enable the buffer. */
1300 	if (!(iio_device_get_current_mode(indio_dev) & INDIO_ALL_TRIGGERED_MODES))
1301 		return -EINVAL;
1302 
1303 	ret = pm_runtime_resume_and_get(st->dev);
1304 	if (ret < 0)
1305 		return ret;
1306 
1307 	/* we continue with the triggered buffer */
1308 	ret = at91_adc_dma_start(indio_dev);
1309 	if (ret) {
1310 		dev_err(&indio_dev->dev, "buffer prepare failed\n");
1311 		goto pm_runtime_put;
1312 	}
1313 
1314 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1315 			 indio_dev->num_channels) {
1316 		struct iio_chan_spec const *chan =
1317 					at91_adc_chan_get(indio_dev, bit);
1318 		if (!chan)
1319 			continue;
1320 		/* these channel types cannot be handled by this trigger */
1321 		if (chan->type == IIO_POSITIONRELATIVE ||
1322 		    chan->type == IIO_PRESSURE ||
1323 		    chan->type == IIO_TEMP)
1324 			continue;
1325 
1326 		at91_adc_cor(st, chan);
1327 
1328 		at91_adc_writel(st, CHER, BIT(chan->channel));
1329 	}
1330 
1331 	if (at91_adc_buffer_check_use_irq(indio_dev, st))
1332 		at91_adc_writel(st, IER, AT91_SAMA5D2_IER_DRDY);
1333 
1334 pm_runtime_put:
1335 	pm_runtime_mark_last_busy(st->dev);
1336 	pm_runtime_put_autosuspend(st->dev);
1337 	return ret;
1338 }
1339 
1340 static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev)
1341 {
1342 	struct at91_adc_state *st = iio_priv(indio_dev);
1343 	int ret;
1344 	u8 bit;
1345 
1346 	/* check if we are disabling triggered buffer or the touchscreen */
1347 	if (at91_adc_current_chan_is_touch(indio_dev))
1348 		return at91_adc_configure_touch(st, false);
1349 
1350 	/* if we are not in triggered mode, nothing to do here */
1351 	if (!(iio_device_get_current_mode(indio_dev) & INDIO_ALL_TRIGGERED_MODES))
1352 		return -EINVAL;
1353 
1354 	ret = pm_runtime_resume_and_get(st->dev);
1355 	if (ret < 0)
1356 		return ret;
1357 
1358 	/*
1359 	 * For each enable channel we must disable it in hardware.
1360 	 * In the case of DMA, we must read the last converted value
1361 	 * to clear EOC status and not get a possible interrupt later.
1362 	 * This value is being read by DMA from LCDR anyway, so it's not lost.
1363 	 */
1364 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1365 			 indio_dev->num_channels) {
1366 		struct iio_chan_spec const *chan =
1367 					at91_adc_chan_get(indio_dev, bit);
1368 
1369 		if (!chan)
1370 			continue;
1371 		/* these channel types are virtual, no need to do anything */
1372 		if (chan->type == IIO_POSITIONRELATIVE ||
1373 		    chan->type == IIO_PRESSURE ||
1374 		    chan->type == IIO_TEMP)
1375 			continue;
1376 
1377 		at91_adc_writel(st, CHDR, BIT(chan->channel));
1378 
1379 		if (st->dma_st.dma_chan)
1380 			at91_adc_read_chan(st, chan->address);
1381 	}
1382 
1383 	if (at91_adc_buffer_check_use_irq(indio_dev, st))
1384 		at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_DRDY);
1385 
1386 	/* read overflow register to clear possible overflow status */
1387 	at91_adc_readl(st, OVER);
1388 
1389 	/* if we are using DMA we must clear registers and end DMA */
1390 	if (st->dma_st.dma_chan)
1391 		dmaengine_terminate_sync(st->dma_st.dma_chan);
1392 
1393 	pm_runtime_mark_last_busy(st->dev);
1394 	pm_runtime_put_autosuspend(st->dev);
1395 
1396 	return 0;
1397 }
1398 
1399 static const struct iio_buffer_setup_ops at91_buffer_setup_ops = {
1400 	.postdisable = &at91_adc_buffer_postdisable,
1401 };
1402 
1403 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio,
1404 						     char *trigger_name)
1405 {
1406 	struct iio_trigger *trig;
1407 	int ret;
1408 
1409 	trig = devm_iio_trigger_alloc(&indio->dev, "%s-dev%d-%s", indio->name,
1410 				iio_device_id(indio), trigger_name);
1411 	if (!trig)
1412 		return NULL;
1413 
1414 	trig->dev.parent = indio->dev.parent;
1415 	iio_trigger_set_drvdata(trig, indio);
1416 	trig->ops = &at91_adc_trigger_ops;
1417 
1418 	ret = devm_iio_trigger_register(&indio->dev, trig);
1419 	if (ret)
1420 		return ERR_PTR(ret);
1421 
1422 	return trig;
1423 }
1424 
1425 static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
1426 					   struct iio_poll_func *pf)
1427 {
1428 	struct at91_adc_state *st = iio_priv(indio_dev);
1429 	int i = 0;
1430 	int val;
1431 	u8 bit;
1432 	u32 mask = at91_adc_active_scan_mask_to_reg(indio_dev);
1433 	unsigned int timeout = 50;
1434 	u32 status, imr, eoc = 0, eoc_imr;
1435 
1436 	/*
1437 	 * Check if the conversion is ready. If not, wait a little bit, and
1438 	 * in case of timeout exit with an error.
1439 	 */
1440 	while (((eoc & mask) != mask) && timeout) {
1441 		at91_adc_irq_status(st, &status, &eoc);
1442 		at91_adc_irq_mask(st, &imr, &eoc_imr);
1443 		usleep_range(50, 100);
1444 		timeout--;
1445 	}
1446 
1447 	/* Cannot read data, not ready. Continue without reporting data */
1448 	if (!timeout)
1449 		return;
1450 
1451 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1452 			 indio_dev->num_channels) {
1453 		struct iio_chan_spec const *chan =
1454 					at91_adc_chan_get(indio_dev, bit);
1455 
1456 		if (!chan)
1457 			continue;
1458 		/*
1459 		 * Our external trigger only supports the voltage channels.
1460 		 * In case someone requested a different type of channel
1461 		 * just put zeroes to buffer.
1462 		 * This should not happen because we check the scan mode
1463 		 * and scan mask when we enable the buffer, and we don't allow
1464 		 * the buffer to start with a mixed mask (voltage and something
1465 		 * else).
1466 		 * Thus, emit a warning.
1467 		 */
1468 		if (chan->type == IIO_VOLTAGE) {
1469 			val = at91_adc_read_chan(st, chan->address);
1470 			at91_adc_adjust_val_osr(st, &val);
1471 			st->buffer[i] = val;
1472 		} else {
1473 			st->buffer[i] = 0;
1474 			WARN(true, "This trigger cannot handle this type of channel");
1475 		}
1476 		i++;
1477 	}
1478 	iio_push_to_buffers_with_timestamp(indio_dev, st->buffer,
1479 					   pf->timestamp);
1480 }
1481 
1482 static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev)
1483 {
1484 	struct at91_adc_state *st = iio_priv(indio_dev);
1485 	int transferred_len = at91_adc_dma_size_done(st);
1486 	s64 ns = iio_get_time_ns(indio_dev);
1487 	s64 interval;
1488 	int sample_index = 0, sample_count, sample_size;
1489 
1490 	u32 status = at91_adc_readl(st, ISR);
1491 	/* if we reached this point, we cannot sample faster */
1492 	if (status & AT91_SAMA5D2_IER_GOVRE)
1493 		pr_info_ratelimited("%s: conversion overrun detected\n",
1494 				    indio_dev->name);
1495 
1496 	sample_size = div_s64(st->dma_st.rx_buf_sz, st->dma_st.watermark);
1497 
1498 	sample_count = div_s64(transferred_len, sample_size);
1499 
1500 	/*
1501 	 * interval between samples is total time since last transfer handling
1502 	 * divided by the number of samples (total size divided by sample size)
1503 	 */
1504 	interval = div_s64((ns - st->dma_st.dma_ts), sample_count);
1505 
1506 	while (transferred_len >= sample_size) {
1507 		/*
1508 		 * for all the values in the current sample,
1509 		 * adjust the values inside the buffer for oversampling
1510 		 */
1511 		at91_adc_adjust_val_osr_array(st,
1512 					&st->dma_st.rx_buf[st->dma_st.buf_idx],
1513 					sample_size);
1514 
1515 		iio_push_to_buffers_with_timestamp(indio_dev,
1516 				(st->dma_st.rx_buf + st->dma_st.buf_idx),
1517 				(st->dma_st.dma_ts + interval * sample_index));
1518 		/* adjust remaining length */
1519 		transferred_len -= sample_size;
1520 		/* adjust buffer index */
1521 		st->dma_st.buf_idx += sample_size;
1522 		/* in case of reaching end of buffer, reset index */
1523 		if (st->dma_st.buf_idx >= st->dma_st.rx_buf_sz)
1524 			st->dma_st.buf_idx = 0;
1525 		sample_index++;
1526 	}
1527 	/* adjust saved time for next transfer handling */
1528 	st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
1529 }
1530 
1531 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
1532 {
1533 	struct iio_poll_func *pf = p;
1534 	struct iio_dev *indio_dev = pf->indio_dev;
1535 	struct at91_adc_state *st = iio_priv(indio_dev);
1536 
1537 	/*
1538 	 * If it's not our trigger, start a conversion now, as we are
1539 	 * actually polling the trigger now.
1540 	 */
1541 	if (iio_trigger_validate_own_device(indio_dev->trig, indio_dev))
1542 		at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
1543 
1544 	if (st->dma_st.dma_chan)
1545 		at91_adc_trigger_handler_dma(indio_dev);
1546 	else
1547 		at91_adc_trigger_handler_nodma(indio_dev, pf);
1548 
1549 	iio_trigger_notify_done(indio_dev->trig);
1550 
1551 	return IRQ_HANDLED;
1552 }
1553 
1554 static unsigned at91_adc_startup_time(unsigned startup_time_min,
1555 				      unsigned adc_clk_khz)
1556 {
1557 	static const unsigned int startup_lookup[] = {
1558 		  0,   8,  16,  24,
1559 		 64,  80,  96, 112,
1560 		512, 576, 640, 704,
1561 		768, 832, 896, 960
1562 		};
1563 	unsigned ticks_min, i;
1564 
1565 	/*
1566 	 * Since the adc frequency is checked before, there is no reason
1567 	 * to not meet the startup time constraint.
1568 	 */
1569 
1570 	ticks_min = startup_time_min * adc_clk_khz / 1000;
1571 	for (i = 0; i < ARRAY_SIZE(startup_lookup); i++)
1572 		if (startup_lookup[i] > ticks_min)
1573 			break;
1574 
1575 	return i;
1576 }
1577 
1578 static void at91_adc_setup_samp_freq(struct iio_dev *indio_dev, unsigned freq,
1579 				     unsigned int startup_time,
1580 				     unsigned int tracktim)
1581 {
1582 	struct at91_adc_state *st = iio_priv(indio_dev);
1583 	unsigned f_per, prescal, startup, mr;
1584 	int ret;
1585 
1586 	f_per = clk_get_rate(st->per_clk);
1587 	prescal = (f_per / (2 * freq)) - 1;
1588 
1589 	startup = at91_adc_startup_time(startup_time, freq / 1000);
1590 
1591 	ret = pm_runtime_resume_and_get(st->dev);
1592 	if (ret < 0)
1593 		return;
1594 
1595 	mr = at91_adc_readl(st, MR);
1596 	mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK);
1597 	mr |= AT91_SAMA5D2_MR_STARTUP(startup);
1598 	mr |= AT91_SAMA5D2_MR_PRESCAL(prescal);
1599 	mr |= AT91_SAMA5D2_MR_TRACKTIM(tracktim);
1600 	at91_adc_writel(st, MR, mr);
1601 
1602 	pm_runtime_mark_last_busy(st->dev);
1603 	pm_runtime_put_autosuspend(st->dev);
1604 
1605 	dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u, tracktim=%u\n",
1606 		freq, startup, prescal, tracktim);
1607 	st->current_sample_rate = freq;
1608 }
1609 
1610 static inline unsigned at91_adc_get_sample_freq(struct at91_adc_state *st)
1611 {
1612 	return st->current_sample_rate;
1613 }
1614 
1615 static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
1616 {
1617 	struct at91_adc_state *st = iio_priv(indio_dev);
1618 	u8 bit;
1619 	u16 val;
1620 	int i = 0;
1621 
1622 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1623 			 st->soc_info.platform->max_index + 1) {
1624 		struct iio_chan_spec const *chan =
1625 					 at91_adc_chan_get(indio_dev, bit);
1626 
1627 		if (chan->type == IIO_POSITIONRELATIVE)
1628 			at91_adc_read_position(st, chan->channel, &val);
1629 		else if (chan->type == IIO_PRESSURE)
1630 			at91_adc_read_pressure(st, chan->channel, &val);
1631 		else
1632 			continue;
1633 		st->buffer[i] = val;
1634 		i++;
1635 	}
1636 	/*
1637 	 * Schedule work to push to buffers.
1638 	 * This is intended to push to the callback buffer that another driver
1639 	 * registered. We are still in a handler from our IRQ. If we push
1640 	 * directly, it means the other driver has it's callback called
1641 	 * from our IRQ context. Which is something we better avoid.
1642 	 * Let's schedule it after our IRQ is completed.
1643 	 */
1644 	schedule_work(&st->touch_st.workq);
1645 }
1646 
1647 static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st)
1648 {
1649 	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_PEN);
1650 	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_NOPEN |
1651 			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1652 			AT91_SAMA5D2_IER_PRDY);
1653 	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
1654 			AT91_SAMA5D2_TRGR_TRGPER(st->touch_st.sample_period_val));
1655 	st->touch_st.touching = true;
1656 }
1657 
1658 static void at91_adc_no_pen_detect_interrupt(struct iio_dev *indio_dev)
1659 {
1660 	struct at91_adc_state *st = iio_priv(indio_dev);
1661 
1662 	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
1663 	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_NOPEN |
1664 			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1665 			AT91_SAMA5D2_IER_PRDY);
1666 	st->touch_st.touching = false;
1667 
1668 	at91_adc_touch_data_handler(indio_dev);
1669 
1670 	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
1671 }
1672 
1673 static void at91_adc_workq_handler(struct work_struct *workq)
1674 {
1675 	struct at91_adc_touch *touch_st = container_of(workq,
1676 					struct at91_adc_touch, workq);
1677 	struct at91_adc_state *st = container_of(touch_st,
1678 					struct at91_adc_state, touch_st);
1679 	struct iio_dev *indio_dev = st->indio_dev;
1680 
1681 	iio_push_to_buffers(indio_dev, st->buffer);
1682 }
1683 
1684 static irqreturn_t at91_adc_interrupt(int irq, void *private)
1685 {
1686 	struct iio_dev *indio = private;
1687 	struct at91_adc_state *st = iio_priv(indio);
1688 	u32 status, eoc, imr, eoc_imr;
1689 	u32 rdy_mask = AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1690 			AT91_SAMA5D2_IER_PRDY;
1691 
1692 	at91_adc_irq_status(st, &status, &eoc);
1693 	at91_adc_irq_mask(st, &imr, &eoc_imr);
1694 
1695 	if (!(status & imr) && !(eoc & eoc_imr))
1696 		return IRQ_NONE;
1697 	if (status & AT91_SAMA5D2_IER_PEN) {
1698 		/* pen detected IRQ */
1699 		at91_adc_pen_detect_interrupt(st);
1700 	} else if ((status & AT91_SAMA5D2_IER_NOPEN)) {
1701 		/* nopen detected IRQ */
1702 		at91_adc_no_pen_detect_interrupt(indio);
1703 	} else if ((status & AT91_SAMA5D2_ISR_PENS) &&
1704 		   ((status & rdy_mask) == rdy_mask)) {
1705 		/* periodic trigger IRQ - during pen sense */
1706 		at91_adc_touch_data_handler(indio);
1707 	} else if (status & AT91_SAMA5D2_ISR_PENS) {
1708 		/*
1709 		 * touching, but the measurements are not ready yet.
1710 		 * read and ignore.
1711 		 */
1712 		status = at91_adc_readl(st, XPOSR);
1713 		status = at91_adc_readl(st, YPOSR);
1714 		status = at91_adc_readl(st, PRESSR);
1715 	} else if (iio_buffer_enabled(indio) &&
1716 		   (status & AT91_SAMA5D2_IER_DRDY)) {
1717 		/* triggered buffer without DMA */
1718 		disable_irq_nosync(irq);
1719 		iio_trigger_poll(indio->trig);
1720 	} else if (iio_buffer_enabled(indio) && st->dma_st.dma_chan) {
1721 		/* triggered buffer with DMA - should not happen */
1722 		disable_irq_nosync(irq);
1723 		WARN(true, "Unexpected irq occurred\n");
1724 	} else if (!iio_buffer_enabled(indio)) {
1725 		/* software requested conversion */
1726 		st->conversion_value = at91_adc_read_chan(st, st->chan->address);
1727 		st->conversion_done = true;
1728 		wake_up_interruptible(&st->wq_data_available);
1729 	}
1730 	return IRQ_HANDLED;
1731 }
1732 
1733 /* This needs to be called with direct mode claimed and st->lock locked. */
1734 static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
1735 				  struct iio_chan_spec const *chan, int *val)
1736 {
1737 	struct at91_adc_state *st = iio_priv(indio_dev);
1738 	u16 tmp_val;
1739 	int ret;
1740 
1741 	ret = pm_runtime_resume_and_get(st->dev);
1742 	if (ret < 0)
1743 		return ret;
1744 
1745 	/*
1746 	 * Keep in mind that we cannot use software trigger or touchscreen
1747 	 * if external trigger is enabled
1748 	 */
1749 	if (chan->type == IIO_POSITIONRELATIVE) {
1750 		ret = at91_adc_read_position(st, chan->channel,
1751 					     &tmp_val);
1752 		*val = tmp_val;
1753 		if (ret > 0)
1754 			ret = at91_adc_adjust_val_osr(st, val);
1755 
1756 		goto pm_runtime_put;
1757 	}
1758 	if (chan->type == IIO_PRESSURE) {
1759 		ret = at91_adc_read_pressure(st, chan->channel,
1760 					     &tmp_val);
1761 		*val = tmp_val;
1762 		if (ret > 0)
1763 			ret = at91_adc_adjust_val_osr(st, val);
1764 
1765 		goto pm_runtime_put;
1766 	}
1767 
1768 	/* in this case we have a voltage or temperature channel */
1769 
1770 	st->chan = chan;
1771 
1772 	at91_adc_cor(st, chan);
1773 	at91_adc_writel(st, CHER, BIT(chan->channel));
1774 	/*
1775 	 * TEMPMR.TEMPON needs to update after CHER otherwise if none
1776 	 * of the channels are enabled and TEMPMR.TEMPON = 1 will
1777 	 * trigger DRDY interruption while preparing for temperature read.
1778 	 */
1779 	if (chan->type == IIO_TEMP)
1780 		at91_adc_writel(st, TEMPMR, AT91_SAMA5D2_TEMPMR_TEMPON);
1781 	at91_adc_eoc_ena(st, chan->channel);
1782 	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
1783 
1784 	ret = wait_event_interruptible_timeout(st->wq_data_available,
1785 					       st->conversion_done,
1786 					       msecs_to_jiffies(1000));
1787 	if (ret == 0)
1788 		ret = -ETIMEDOUT;
1789 
1790 	if (ret > 0) {
1791 		*val = st->conversion_value;
1792 		ret = at91_adc_adjust_val_osr(st, val);
1793 		if (chan->scan_type.sign == 's')
1794 			*val = sign_extend32(*val,
1795 					     chan->scan_type.realbits - 1);
1796 		st->conversion_done = false;
1797 	}
1798 
1799 	at91_adc_eoc_dis(st, st->chan->channel);
1800 	if (chan->type == IIO_TEMP)
1801 		at91_adc_writel(st, TEMPMR, 0U);
1802 	at91_adc_writel(st, CHDR, BIT(chan->channel));
1803 
1804 	/* Needed to ACK the DRDY interruption */
1805 	at91_adc_readl(st, LCDR);
1806 
1807 pm_runtime_put:
1808 	pm_runtime_mark_last_busy(st->dev);
1809 	pm_runtime_put_autosuspend(st->dev);
1810 	return ret;
1811 }
1812 
1813 static int at91_adc_read_info_locked(struct iio_dev *indio_dev,
1814 				     struct iio_chan_spec const *chan, int *val)
1815 {
1816 	struct at91_adc_state *st = iio_priv(indio_dev);
1817 	int ret;
1818 
1819 	ret = iio_device_claim_direct_mode(indio_dev);
1820 	if (ret)
1821 		return ret;
1822 
1823 	mutex_lock(&st->lock);
1824 	ret = at91_adc_read_info_raw(indio_dev, chan, val);
1825 	mutex_unlock(&st->lock);
1826 
1827 	iio_device_release_direct_mode(indio_dev);
1828 
1829 	return ret;
1830 }
1831 
1832 static void at91_adc_temp_sensor_configure(struct at91_adc_state *st,
1833 					   bool start)
1834 {
1835 	u32 sample_rate, oversampling_ratio;
1836 	u32 startup_time, tracktim, trackx;
1837 
1838 	if (start) {
1839 		/*
1840 		 * Configure the sensor for best accuracy: 10MHz frequency,
1841 		 * oversampling rate of 256, tracktim=0xf and trackx=1.
1842 		 */
1843 		sample_rate = 10 * MEGA;
1844 		oversampling_ratio = 256;
1845 		startup_time = AT91_SAMA5D2_MR_STARTUP_TS_MIN;
1846 		tracktim = AT91_SAMA5D2_MR_TRACKTIM_TS;
1847 		trackx = AT91_SAMA5D2_TRACKX_TS;
1848 
1849 		st->temp_st.saved_sample_rate = st->current_sample_rate;
1850 		st->temp_st.saved_oversampling = st->oversampling_ratio;
1851 	} else {
1852 		/* Go back to previous settings. */
1853 		sample_rate = st->temp_st.saved_sample_rate;
1854 		oversampling_ratio = st->temp_st.saved_oversampling;
1855 		startup_time = st->soc_info.startup_time;
1856 		tracktim = 0;
1857 		trackx = 0;
1858 	}
1859 
1860 	at91_adc_setup_samp_freq(st->indio_dev, sample_rate, startup_time,
1861 				 tracktim);
1862 	at91_adc_config_emr(st, oversampling_ratio, trackx);
1863 }
1864 
1865 static int at91_adc_read_temp(struct iio_dev *indio_dev,
1866 			      struct iio_chan_spec const *chan, int *val)
1867 {
1868 	struct at91_adc_state *st = iio_priv(indio_dev);
1869 	struct at91_adc_temp_sensor_clb *clb = &st->soc_info.temp_sensor_clb;
1870 	u64 div1, div2;
1871 	u32 tmp;
1872 	int ret, vbg, vtemp;
1873 
1874 	ret = iio_device_claim_direct_mode(indio_dev);
1875 	if (ret)
1876 		return ret;
1877 	mutex_lock(&st->lock);
1878 
1879 	ret = pm_runtime_resume_and_get(st->dev);
1880 	if (ret < 0)
1881 		goto unlock;
1882 
1883 	at91_adc_temp_sensor_configure(st, true);
1884 
1885 	/* Read VBG. */
1886 	tmp = at91_adc_readl(st, ACR);
1887 	tmp |= AT91_SAMA5D2_ACR_SRCLCH;
1888 	at91_adc_writel(st, ACR, tmp);
1889 	ret = at91_adc_read_info_raw(indio_dev, chan, &vbg);
1890 	if (ret < 0)
1891 		goto restore_config;
1892 
1893 	/* Read VTEMP. */
1894 	tmp &= ~AT91_SAMA5D2_ACR_SRCLCH;
1895 	at91_adc_writel(st, ACR, tmp);
1896 	ret = at91_adc_read_info_raw(indio_dev, chan, &vtemp);
1897 
1898 restore_config:
1899 	/* Revert previous settings. */
1900 	at91_adc_temp_sensor_configure(st, false);
1901 	pm_runtime_mark_last_busy(st->dev);
1902 	pm_runtime_put_autosuspend(st->dev);
1903 unlock:
1904 	mutex_unlock(&st->lock);
1905 	iio_device_release_direct_mode(indio_dev);
1906 	if (ret < 0)
1907 		return ret;
1908 
1909 	/*
1910 	 * Temp[milli] = p1[milli] + (vtemp * clb->p6 - clb->p4 * vbg)/
1911 	 *			     (vbg * AT91_ADC_TS_VTEMP_DT)
1912 	 */
1913 	div1 = DIV_ROUND_CLOSEST_ULL(((u64)vtemp * clb->p6), vbg);
1914 	div1 = DIV_ROUND_CLOSEST_ULL((div1 * 1000), AT91_ADC_TS_VTEMP_DT);
1915 	div2 = DIV_ROUND_CLOSEST_ULL((u64)clb->p4, AT91_ADC_TS_VTEMP_DT);
1916 	div2 *= 1000;
1917 	*val = clb->p1 + (int)div1 - (int)div2;
1918 
1919 	return ret;
1920 }
1921 
1922 static int at91_adc_read_raw(struct iio_dev *indio_dev,
1923 			     struct iio_chan_spec const *chan,
1924 			     int *val, int *val2, long mask)
1925 {
1926 	struct at91_adc_state *st = iio_priv(indio_dev);
1927 
1928 	switch (mask) {
1929 	case IIO_CHAN_INFO_RAW:
1930 		return at91_adc_read_info_locked(indio_dev, chan, val);
1931 
1932 	case IIO_CHAN_INFO_SCALE:
1933 		*val = st->vref_uv / 1000;
1934 		if (chan->differential)
1935 			*val *= 2;
1936 		*val2 = chan->scan_type.realbits;
1937 		return IIO_VAL_FRACTIONAL_LOG2;
1938 
1939 	case IIO_CHAN_INFO_PROCESSED:
1940 		if (chan->type != IIO_TEMP)
1941 			return -EINVAL;
1942 		return at91_adc_read_temp(indio_dev, chan, val);
1943 
1944 	case IIO_CHAN_INFO_SAMP_FREQ:
1945 		*val = at91_adc_get_sample_freq(st);
1946 		return IIO_VAL_INT;
1947 
1948 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1949 		*val = st->oversampling_ratio;
1950 		return IIO_VAL_INT;
1951 
1952 	default:
1953 		return -EINVAL;
1954 	}
1955 }
1956 
1957 static int at91_adc_write_raw(struct iio_dev *indio_dev,
1958 			      struct iio_chan_spec const *chan,
1959 			      int val, int val2, long mask)
1960 {
1961 	struct at91_adc_state *st = iio_priv(indio_dev);
1962 	int ret;
1963 
1964 	switch (mask) {
1965 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1966 		/* if no change, optimize out */
1967 		if (val == st->oversampling_ratio)
1968 			return 0;
1969 
1970 		ret = iio_device_claim_direct_mode(indio_dev);
1971 		if (ret)
1972 			return ret;
1973 		mutex_lock(&st->lock);
1974 		/* update ratio */
1975 		ret = at91_adc_config_emr(st, val, 0);
1976 		mutex_unlock(&st->lock);
1977 		iio_device_release_direct_mode(indio_dev);
1978 		return ret;
1979 	case IIO_CHAN_INFO_SAMP_FREQ:
1980 		if (val < st->soc_info.min_sample_rate ||
1981 		    val > st->soc_info.max_sample_rate)
1982 			return -EINVAL;
1983 
1984 		ret = iio_device_claim_direct_mode(indio_dev);
1985 		if (ret)
1986 			return ret;
1987 		mutex_lock(&st->lock);
1988 		at91_adc_setup_samp_freq(indio_dev, val,
1989 					 st->soc_info.startup_time, 0);
1990 		mutex_unlock(&st->lock);
1991 		iio_device_release_direct_mode(indio_dev);
1992 		return 0;
1993 	default:
1994 		return -EINVAL;
1995 	}
1996 }
1997 
1998 static int at91_adc_read_avail(struct iio_dev *indio_dev,
1999 			       struct iio_chan_spec const *chan,
2000 			       const int **vals, int *type, int *length,
2001 			       long mask)
2002 {
2003 	struct at91_adc_state *st = iio_priv(indio_dev);
2004 
2005 	switch (mask) {
2006 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
2007 		*vals = (int *)st->soc_info.platform->oversampling_avail;
2008 		*type = IIO_VAL_INT;
2009 		*length = st->soc_info.platform->oversampling_avail_no;
2010 		return IIO_AVAIL_LIST;
2011 	default:
2012 		return -EINVAL;
2013 	}
2014 }
2015 
2016 static void at91_adc_dma_init(struct at91_adc_state *st)
2017 {
2018 	struct device *dev = &st->indio_dev->dev;
2019 	struct dma_slave_config config = {0};
2020 	/* we have 2 bytes for each channel */
2021 	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
2022 	/*
2023 	 * We make the buffer double the size of the fifo,
2024 	 * such that DMA uses one half of the buffer (full fifo size)
2025 	 * and the software uses the other half to read/write.
2026 	 */
2027 	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
2028 					  sample_size * 2, PAGE_SIZE);
2029 
2030 	if (st->dma_st.dma_chan)
2031 		return;
2032 
2033 	st->dma_st.dma_chan = dma_request_chan(dev, "rx");
2034 	if (IS_ERR(st->dma_st.dma_chan))  {
2035 		dev_info(dev, "can't get DMA channel\n");
2036 		st->dma_st.dma_chan = NULL;
2037 		goto dma_exit;
2038 	}
2039 
2040 	st->dma_st.rx_buf = dma_alloc_coherent(st->dma_st.dma_chan->device->dev,
2041 					       pages * PAGE_SIZE,
2042 					       &st->dma_st.rx_dma_buf,
2043 					       GFP_KERNEL);
2044 	if (!st->dma_st.rx_buf) {
2045 		dev_info(dev, "can't allocate coherent DMA area\n");
2046 		goto dma_chan_disable;
2047 	}
2048 
2049 	/* Configure DMA channel to read data register */
2050 	config.direction = DMA_DEV_TO_MEM;
2051 	config.src_addr = (phys_addr_t)(st->dma_st.phys_addr
2052 			  + st->soc_info.platform->layout->LCDR);
2053 	config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
2054 	config.src_maxburst = 1;
2055 	config.dst_maxburst = 1;
2056 
2057 	if (dmaengine_slave_config(st->dma_st.dma_chan, &config)) {
2058 		dev_info(dev, "can't configure DMA slave\n");
2059 		goto dma_free_area;
2060 	}
2061 
2062 	dev_info(dev, "using %s for rx DMA transfers\n",
2063 		 dma_chan_name(st->dma_st.dma_chan));
2064 
2065 	return;
2066 
2067 dma_free_area:
2068 	dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
2069 			  st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
2070 dma_chan_disable:
2071 	dma_release_channel(st->dma_st.dma_chan);
2072 	st->dma_st.dma_chan = NULL;
2073 dma_exit:
2074 	dev_info(dev, "continuing without DMA support\n");
2075 }
2076 
2077 static void at91_adc_dma_disable(struct at91_adc_state *st)
2078 {
2079 	struct device *dev = &st->indio_dev->dev;
2080 	/* we have 2 bytes for each channel */
2081 	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
2082 	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
2083 					  sample_size * 2, PAGE_SIZE);
2084 
2085 	/* if we are not using DMA, just return */
2086 	if (!st->dma_st.dma_chan)
2087 		return;
2088 
2089 	/* wait for all transactions to be terminated first*/
2090 	dmaengine_terminate_sync(st->dma_st.dma_chan);
2091 
2092 	dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
2093 			  st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
2094 	dma_release_channel(st->dma_st.dma_chan);
2095 	st->dma_st.dma_chan = NULL;
2096 
2097 	dev_info(dev, "continuing without DMA support\n");
2098 }
2099 
2100 static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
2101 {
2102 	struct at91_adc_state *st = iio_priv(indio_dev);
2103 	int ret;
2104 
2105 	if (val > AT91_HWFIFO_MAX_SIZE)
2106 		val = AT91_HWFIFO_MAX_SIZE;
2107 
2108 	if (!st->selected_trig->hw_trig) {
2109 		dev_dbg(&indio_dev->dev, "we need hw trigger for DMA\n");
2110 		return 0;
2111 	}
2112 
2113 	dev_dbg(&indio_dev->dev, "new watermark is %u\n", val);
2114 	st->dma_st.watermark = val;
2115 
2116 	/*
2117 	 * The logic here is: if we have watermark 1, it means we do
2118 	 * each conversion with it's own IRQ, thus we don't need DMA.
2119 	 * If the watermark is higher, we do DMA to do all the transfers in bulk
2120 	 */
2121 
2122 	if (val == 1)
2123 		at91_adc_dma_disable(st);
2124 	else if (val > 1)
2125 		at91_adc_dma_init(st);
2126 
2127 	/*
2128 	 * We can start the DMA only after setting the watermark and
2129 	 * having the DMA initialization completed
2130 	 */
2131 	ret = at91_adc_buffer_prepare(indio_dev);
2132 	if (ret)
2133 		at91_adc_dma_disable(st);
2134 
2135 	return ret;
2136 }
2137 
2138 static int at91_adc_update_scan_mode(struct iio_dev *indio_dev,
2139 				     const unsigned long *scan_mask)
2140 {
2141 	struct at91_adc_state *st = iio_priv(indio_dev);
2142 
2143 	if (bitmap_subset(scan_mask, &st->touch_st.channels_bitmask,
2144 			  st->soc_info.platform->max_index + 1))
2145 		return 0;
2146 	/*
2147 	 * if the new bitmap is a combination of touchscreen and regular
2148 	 * channels, then we are not fine
2149 	 */
2150 	if (bitmap_intersects(&st->touch_st.channels_bitmask, scan_mask,
2151 			      st->soc_info.platform->max_index + 1))
2152 		return -EINVAL;
2153 	return 0;
2154 }
2155 
2156 static void at91_adc_hw_init(struct iio_dev *indio_dev)
2157 {
2158 	struct at91_adc_state *st = iio_priv(indio_dev);
2159 
2160 	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
2161 	if (st->soc_info.platform->layout->EOC_IDR)
2162 		at91_adc_writel(st, EOC_IDR, 0xffffffff);
2163 	at91_adc_writel(st, IDR, 0xffffffff);
2164 	/*
2165 	 * Transfer field must be set to 2 according to the datasheet and
2166 	 * allows different analog settings for each channel.
2167 	 */
2168 	at91_adc_writel(st, MR,
2169 			AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH);
2170 
2171 	at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate,
2172 				 st->soc_info.startup_time, 0);
2173 
2174 	/* configure extended mode register */
2175 	at91_adc_config_emr(st, st->oversampling_ratio, 0);
2176 }
2177 
2178 static ssize_t at91_adc_get_fifo_state(struct device *dev,
2179 				       struct device_attribute *attr, char *buf)
2180 {
2181 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
2182 	struct at91_adc_state *st = iio_priv(indio_dev);
2183 
2184 	return scnprintf(buf, PAGE_SIZE, "%d\n", !!st->dma_st.dma_chan);
2185 }
2186 
2187 static ssize_t at91_adc_get_watermark(struct device *dev,
2188 				      struct device_attribute *attr, char *buf)
2189 {
2190 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
2191 	struct at91_adc_state *st = iio_priv(indio_dev);
2192 
2193 	return scnprintf(buf, PAGE_SIZE, "%d\n", st->dma_st.watermark);
2194 }
2195 
2196 static IIO_DEVICE_ATTR(hwfifo_enabled, 0444,
2197 		       at91_adc_get_fifo_state, NULL, 0);
2198 static IIO_DEVICE_ATTR(hwfifo_watermark, 0444,
2199 		       at91_adc_get_watermark, NULL, 0);
2200 
2201 static IIO_CONST_ATTR(hwfifo_watermark_min, "2");
2202 static IIO_CONST_ATTR(hwfifo_watermark_max, AT91_HWFIFO_MAX_SIZE_STR);
2203 
2204 static const struct attribute *at91_adc_fifo_attributes[] = {
2205 	&iio_const_attr_hwfifo_watermark_min.dev_attr.attr,
2206 	&iio_const_attr_hwfifo_watermark_max.dev_attr.attr,
2207 	&iio_dev_attr_hwfifo_watermark.dev_attr.attr,
2208 	&iio_dev_attr_hwfifo_enabled.dev_attr.attr,
2209 	NULL,
2210 };
2211 
2212 static const struct iio_info at91_adc_info = {
2213 	.read_avail = &at91_adc_read_avail,
2214 	.read_raw = &at91_adc_read_raw,
2215 	.write_raw = &at91_adc_write_raw,
2216 	.update_scan_mode = &at91_adc_update_scan_mode,
2217 	.fwnode_xlate = &at91_adc_fwnode_xlate,
2218 	.hwfifo_set_watermark = &at91_adc_set_watermark,
2219 };
2220 
2221 static int at91_adc_buffer_and_trigger_init(struct device *dev,
2222 					    struct iio_dev *indio)
2223 {
2224 	struct at91_adc_state *st = iio_priv(indio);
2225 	const struct attribute **fifo_attrs;
2226 	int ret;
2227 
2228 	if (st->selected_trig->hw_trig)
2229 		fifo_attrs = at91_adc_fifo_attributes;
2230 	else
2231 		fifo_attrs = NULL;
2232 
2233 	ret = devm_iio_triggered_buffer_setup_ext(&indio->dev, indio,
2234 		&iio_pollfunc_store_time, &at91_adc_trigger_handler,
2235 		IIO_BUFFER_DIRECTION_IN, &at91_buffer_setup_ops, fifo_attrs);
2236 	if (ret < 0) {
2237 		dev_err(dev, "couldn't initialize the buffer.\n");
2238 		return ret;
2239 	}
2240 
2241 	if (!st->selected_trig->hw_trig)
2242 		return 0;
2243 
2244 	st->trig = at91_adc_allocate_trigger(indio, st->selected_trig->name);
2245 	if (IS_ERR(st->trig)) {
2246 		dev_err(dev, "could not allocate trigger\n");
2247 		return PTR_ERR(st->trig);
2248 	}
2249 
2250 	/*
2251 	 * Initially the iio buffer has a length of 2 and
2252 	 * a watermark of 1
2253 	 */
2254 	st->dma_st.watermark = 1;
2255 
2256 	return 0;
2257 }
2258 
2259 static int at91_adc_temp_sensor_init(struct at91_adc_state *st,
2260 				     struct device *dev)
2261 {
2262 	struct at91_adc_temp_sensor_clb *clb = &st->soc_info.temp_sensor_clb;
2263 	struct nvmem_cell *temp_calib;
2264 	u32 *buf;
2265 	size_t len;
2266 	int ret = 0;
2267 
2268 	if (!st->soc_info.platform->temp_sensor)
2269 		return 0;
2270 
2271 	/* Get the calibration data from NVMEM. */
2272 	temp_calib = devm_nvmem_cell_get(dev, "temperature_calib");
2273 	if (IS_ERR(temp_calib)) {
2274 		ret = PTR_ERR(temp_calib);
2275 		if (ret != -ENOENT)
2276 			dev_err(dev, "Failed to get temperature_calib cell!\n");
2277 		return ret;
2278 	}
2279 
2280 	buf = nvmem_cell_read(temp_calib, &len);
2281 	if (IS_ERR(buf)) {
2282 		dev_err(dev, "Failed to read calibration data!\n");
2283 		return PTR_ERR(buf);
2284 	}
2285 	if (len < AT91_ADC_TS_CLB_IDX_MAX * 4) {
2286 		dev_err(dev, "Invalid calibration data!\n");
2287 		ret = -EINVAL;
2288 		goto free_buf;
2289 	}
2290 
2291 	/* Store calibration data for later use. */
2292 	clb->p1 = buf[AT91_ADC_TS_CLB_IDX_P1];
2293 	clb->p4 = buf[AT91_ADC_TS_CLB_IDX_P4];
2294 	clb->p6 = buf[AT91_ADC_TS_CLB_IDX_P6];
2295 
2296 	/*
2297 	 * We prepare here the conversion to milli and also add constant
2298 	 * factor (5 degrees Celsius) to p1 here to avoid doing it on
2299 	 * hotpath.
2300 	 */
2301 	clb->p1 = clb->p1 * 1000 + 5000;
2302 
2303 free_buf:
2304 	kfree(buf);
2305 	return ret;
2306 }
2307 
2308 static int at91_adc_probe(struct platform_device *pdev)
2309 {
2310 	struct device *dev = &pdev->dev;
2311 	struct iio_dev *indio_dev;
2312 	struct at91_adc_state *st;
2313 	struct resource	*res;
2314 	int ret, i, num_channels;
2315 	u32 edge_type = IRQ_TYPE_NONE;
2316 
2317 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
2318 	if (!indio_dev)
2319 		return -ENOMEM;
2320 
2321 	st = iio_priv(indio_dev);
2322 	st->indio_dev = indio_dev;
2323 
2324 	st->soc_info.platform = device_get_match_data(dev);
2325 
2326 	ret = at91_adc_temp_sensor_init(st, &pdev->dev);
2327 	/* Don't register temperature channel if initialization failed. */
2328 	if (ret)
2329 		num_channels = st->soc_info.platform->max_channels - 1;
2330 	else
2331 		num_channels = st->soc_info.platform->max_channels;
2332 
2333 	indio_dev->name = dev_name(&pdev->dev);
2334 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
2335 	indio_dev->info = &at91_adc_info;
2336 	indio_dev->channels = *st->soc_info.platform->adc_channels;
2337 	indio_dev->num_channels = num_channels;
2338 
2339 	bitmap_set(&st->touch_st.channels_bitmask,
2340 		   st->soc_info.platform->touch_chan_x, 1);
2341 	bitmap_set(&st->touch_st.channels_bitmask,
2342 		   st->soc_info.platform->touch_chan_y, 1);
2343 	bitmap_set(&st->touch_st.channels_bitmask,
2344 		   st->soc_info.platform->touch_chan_p, 1);
2345 
2346 	st->oversampling_ratio = 1;
2347 
2348 	ret = device_property_read_u32(dev, "atmel,min-sample-rate-hz",
2349 				       &st->soc_info.min_sample_rate);
2350 	if (ret) {
2351 		dev_err(&pdev->dev,
2352 			"invalid or missing value for atmel,min-sample-rate-hz\n");
2353 		return ret;
2354 	}
2355 
2356 	ret = device_property_read_u32(dev, "atmel,max-sample-rate-hz",
2357 				       &st->soc_info.max_sample_rate);
2358 	if (ret) {
2359 		dev_err(&pdev->dev,
2360 			"invalid or missing value for atmel,max-sample-rate-hz\n");
2361 		return ret;
2362 	}
2363 
2364 	ret = device_property_read_u32(dev, "atmel,startup-time-ms",
2365 				       &st->soc_info.startup_time);
2366 	if (ret) {
2367 		dev_err(&pdev->dev,
2368 			"invalid or missing value for atmel,startup-time-ms\n");
2369 		return ret;
2370 	}
2371 
2372 	ret = device_property_read_u32(dev, "atmel,trigger-edge-type",
2373 				       &edge_type);
2374 	if (ret) {
2375 		dev_dbg(&pdev->dev,
2376 			"atmel,trigger-edge-type not specified, only software trigger available\n");
2377 	}
2378 
2379 	st->selected_trig = NULL;
2380 
2381 	/* find the right trigger, or no trigger at all */
2382 	for (i = 0; i < st->soc_info.platform->hw_trig_cnt + 1; i++)
2383 		if (at91_adc_trigger_list[i].edge_type == edge_type) {
2384 			st->selected_trig = &at91_adc_trigger_list[i];
2385 			break;
2386 		}
2387 
2388 	if (!st->selected_trig) {
2389 		dev_err(&pdev->dev, "invalid external trigger edge value\n");
2390 		return -EINVAL;
2391 	}
2392 
2393 	init_waitqueue_head(&st->wq_data_available);
2394 	mutex_init(&st->lock);
2395 	INIT_WORK(&st->touch_st.workq, at91_adc_workq_handler);
2396 
2397 	st->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
2398 	if (IS_ERR(st->base))
2399 		return PTR_ERR(st->base);
2400 
2401 	/* if we plan to use DMA, we need the physical address of the regs */
2402 	st->dma_st.phys_addr = res->start;
2403 
2404 	st->irq = platform_get_irq(pdev, 0);
2405 	if (st->irq <= 0) {
2406 		if (!st->irq)
2407 			st->irq = -ENXIO;
2408 
2409 		return st->irq;
2410 	}
2411 
2412 	st->per_clk = devm_clk_get(&pdev->dev, "adc_clk");
2413 	if (IS_ERR(st->per_clk))
2414 		return PTR_ERR(st->per_clk);
2415 
2416 	st->reg = devm_regulator_get(&pdev->dev, "vddana");
2417 	if (IS_ERR(st->reg))
2418 		return PTR_ERR(st->reg);
2419 
2420 	st->vref = devm_regulator_get(&pdev->dev, "vref");
2421 	if (IS_ERR(st->vref))
2422 		return PTR_ERR(st->vref);
2423 
2424 	ret = devm_request_irq(&pdev->dev, st->irq, at91_adc_interrupt, 0,
2425 			       pdev->dev.driver->name, indio_dev);
2426 	if (ret)
2427 		return ret;
2428 
2429 	ret = regulator_enable(st->reg);
2430 	if (ret)
2431 		return ret;
2432 
2433 	ret = regulator_enable(st->vref);
2434 	if (ret)
2435 		goto reg_disable;
2436 
2437 	st->vref_uv = regulator_get_voltage(st->vref);
2438 	if (st->vref_uv <= 0) {
2439 		ret = -EINVAL;
2440 		goto vref_disable;
2441 	}
2442 
2443 	ret = clk_prepare_enable(st->per_clk);
2444 	if (ret)
2445 		goto vref_disable;
2446 
2447 	platform_set_drvdata(pdev, indio_dev);
2448 	st->dev = &pdev->dev;
2449 	pm_runtime_set_autosuspend_delay(st->dev, 500);
2450 	pm_runtime_use_autosuspend(st->dev);
2451 	pm_runtime_set_active(st->dev);
2452 	pm_runtime_enable(st->dev);
2453 	pm_runtime_get_noresume(st->dev);
2454 
2455 	at91_adc_hw_init(indio_dev);
2456 
2457 	ret = at91_adc_buffer_and_trigger_init(&pdev->dev, indio_dev);
2458 	if (ret < 0)
2459 		goto err_pm_disable;
2460 
2461 	if (dma_coerce_mask_and_coherent(&indio_dev->dev, DMA_BIT_MASK(32)))
2462 		dev_info(&pdev->dev, "cannot set DMA mask to 32-bit\n");
2463 
2464 	ret = iio_device_register(indio_dev);
2465 	if (ret < 0)
2466 		goto dma_disable;
2467 
2468 	if (st->selected_trig->hw_trig)
2469 		dev_info(&pdev->dev, "setting up trigger as %s\n",
2470 			 st->selected_trig->name);
2471 
2472 	dev_info(&pdev->dev, "version: %x\n",
2473 		 readl_relaxed(st->base + st->soc_info.platform->layout->VERSION));
2474 
2475 	pm_runtime_mark_last_busy(st->dev);
2476 	pm_runtime_put_autosuspend(st->dev);
2477 
2478 	return 0;
2479 
2480 dma_disable:
2481 	at91_adc_dma_disable(st);
2482 err_pm_disable:
2483 	pm_runtime_put_noidle(st->dev);
2484 	pm_runtime_disable(st->dev);
2485 	pm_runtime_set_suspended(st->dev);
2486 	pm_runtime_dont_use_autosuspend(st->dev);
2487 	clk_disable_unprepare(st->per_clk);
2488 vref_disable:
2489 	regulator_disable(st->vref);
2490 reg_disable:
2491 	regulator_disable(st->reg);
2492 	return ret;
2493 }
2494 
2495 static int at91_adc_remove(struct platform_device *pdev)
2496 {
2497 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
2498 	struct at91_adc_state *st = iio_priv(indio_dev);
2499 
2500 	iio_device_unregister(indio_dev);
2501 
2502 	at91_adc_dma_disable(st);
2503 
2504 	pm_runtime_disable(st->dev);
2505 	pm_runtime_set_suspended(st->dev);
2506 	clk_disable_unprepare(st->per_clk);
2507 
2508 	regulator_disable(st->vref);
2509 	regulator_disable(st->reg);
2510 
2511 	return 0;
2512 }
2513 
2514 static int at91_adc_suspend(struct device *dev)
2515 {
2516 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2517 	struct at91_adc_state *st = iio_priv(indio_dev);
2518 	int ret;
2519 
2520 	ret = pm_runtime_resume_and_get(st->dev);
2521 	if (ret < 0)
2522 		return ret;
2523 
2524 	if (iio_buffer_enabled(indio_dev))
2525 		at91_adc_buffer_postdisable(indio_dev);
2526 
2527 	/*
2528 	 * Do a sofware reset of the ADC before we go to suspend.
2529 	 * this will ensure that all pins are free from being muxed by the ADC
2530 	 * and can be used by for other devices.
2531 	 * Otherwise, ADC will hog them and we can't go to suspend mode.
2532 	 */
2533 	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
2534 
2535 	pm_runtime_mark_last_busy(st->dev);
2536 	pm_runtime_put_noidle(st->dev);
2537 	clk_disable_unprepare(st->per_clk);
2538 	regulator_disable(st->vref);
2539 	regulator_disable(st->reg);
2540 
2541 	return pinctrl_pm_select_sleep_state(dev);
2542 }
2543 
2544 static int at91_adc_resume(struct device *dev)
2545 {
2546 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2547 	struct at91_adc_state *st = iio_priv(indio_dev);
2548 	int ret;
2549 
2550 	ret = pinctrl_pm_select_default_state(dev);
2551 	if (ret)
2552 		goto resume_failed;
2553 
2554 	ret = regulator_enable(st->reg);
2555 	if (ret)
2556 		goto resume_failed;
2557 
2558 	ret = regulator_enable(st->vref);
2559 	if (ret)
2560 		goto reg_disable_resume;
2561 
2562 	ret = clk_prepare_enable(st->per_clk);
2563 	if (ret)
2564 		goto vref_disable_resume;
2565 
2566 	pm_runtime_get_noresume(st->dev);
2567 
2568 	at91_adc_hw_init(indio_dev);
2569 
2570 	/* reconfiguring trigger hardware state */
2571 	if (iio_buffer_enabled(indio_dev)) {
2572 		ret = at91_adc_buffer_prepare(indio_dev);
2573 		if (ret)
2574 			goto pm_runtime_put;
2575 
2576 		at91_adc_configure_trigger_registers(st, true);
2577 	}
2578 
2579 	pm_runtime_mark_last_busy(st->dev);
2580 	pm_runtime_put_autosuspend(st->dev);
2581 
2582 	return 0;
2583 
2584 pm_runtime_put:
2585 	pm_runtime_mark_last_busy(st->dev);
2586 	pm_runtime_put_noidle(st->dev);
2587 	clk_disable_unprepare(st->per_clk);
2588 vref_disable_resume:
2589 	regulator_disable(st->vref);
2590 reg_disable_resume:
2591 	regulator_disable(st->reg);
2592 resume_failed:
2593 	dev_err(&indio_dev->dev, "failed to resume\n");
2594 	return ret;
2595 }
2596 
2597 static int at91_adc_runtime_suspend(struct device *dev)
2598 {
2599 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2600 	struct at91_adc_state *st = iio_priv(indio_dev);
2601 
2602 	clk_disable(st->per_clk);
2603 
2604 	return 0;
2605 }
2606 
2607 static int at91_adc_runtime_resume(struct device *dev)
2608 {
2609 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2610 	struct at91_adc_state *st = iio_priv(indio_dev);
2611 
2612 	return clk_enable(st->per_clk);
2613 }
2614 
2615 static const struct dev_pm_ops at91_adc_pm_ops = {
2616 	SYSTEM_SLEEP_PM_OPS(at91_adc_suspend, at91_adc_resume)
2617 	RUNTIME_PM_OPS(at91_adc_runtime_suspend, at91_adc_runtime_resume,
2618 		       NULL)
2619 };
2620 
2621 static const struct of_device_id at91_adc_dt_match[] = {
2622 	{
2623 		.compatible = "atmel,sama5d2-adc",
2624 		.data = (const void *)&sama5d2_platform,
2625 	}, {
2626 		.compatible = "microchip,sama7g5-adc",
2627 		.data = (const void *)&sama7g5_platform,
2628 	}, {
2629 		/* sentinel */
2630 	}
2631 };
2632 MODULE_DEVICE_TABLE(of, at91_adc_dt_match);
2633 
2634 static struct platform_driver at91_adc_driver = {
2635 	.probe = at91_adc_probe,
2636 	.remove = at91_adc_remove,
2637 	.driver = {
2638 		.name = "at91-sama5d2_adc",
2639 		.of_match_table = at91_adc_dt_match,
2640 		.pm = pm_ptr(&at91_adc_pm_ops),
2641 	},
2642 };
2643 module_platform_driver(at91_adc_driver)
2644 
2645 MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@microchip.com>");
2646 MODULE_AUTHOR("Eugen Hristev <eugen.hristev@microchip.com");
2647 MODULE_DESCRIPTION("Atmel AT91 SAMA5D2 ADC");
2648 MODULE_LICENSE("GPL v2");
2649