xref: /linux/drivers/iio/adc/at91_adc.c (revision f97661c4c713fa2bdf2649c76b181772e27cf325)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for the ADC present in the Atmel AT91 evaluation boards.
4  *
5  * Copyright 2011 Free Electrons
6  */
7 
8 #include <linux/bitmap.h>
9 #include <linux/bitops.h>
10 #include <linux/cleanup.h>
11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/input.h>
15 #include <linux/interrupt.h>
16 #include <linux/jiffies.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/wait.h>
24 
25 #include <linux/iio/iio.h>
26 #include <linux/iio/buffer.h>
27 #include <linux/iio/trigger.h>
28 #include <linux/iio/trigger_consumer.h>
29 #include <linux/iio/triggered_buffer.h>
30 #include <linux/pinctrl/consumer.h>
31 
32 /* Registers */
33 #define AT91_ADC_CR		0x00		/* Control Register */
34 #define		AT91_ADC_SWRST		(1 << 0)	/* Software Reset */
35 #define		AT91_ADC_START		(1 << 1)	/* Start Conversion */
36 
37 #define AT91_ADC_MR		0x04		/* Mode Register */
38 #define		AT91_ADC_TSAMOD		(3 << 0)	/* ADC mode */
39 #define		AT91_ADC_TSAMOD_ADC_ONLY_MODE		(0 << 0)	/* ADC Mode */
40 #define		AT91_ADC_TSAMOD_TS_ONLY_MODE		(1 << 0)	/* Touch Screen Only Mode */
41 #define		AT91_ADC_TRGEN		(1 << 0)	/* Trigger Enable */
42 #define		AT91_ADC_TRGSEL		(7 << 1)	/* Trigger Selection */
43 #define			AT91_ADC_TRGSEL_TC0		(0 << 1)
44 #define			AT91_ADC_TRGSEL_TC1		(1 << 1)
45 #define			AT91_ADC_TRGSEL_TC2		(2 << 1)
46 #define			AT91_ADC_TRGSEL_EXTERNAL	(6 << 1)
47 #define		AT91_ADC_LOWRES		(1 << 4)	/* Low Resolution */
48 #define		AT91_ADC_SLEEP		(1 << 5)	/* Sleep Mode */
49 #define		AT91_ADC_PENDET		(1 << 6)	/* Pen contact detection enable */
50 #define		AT91_ADC_PRESCAL_9260	(0x3f << 8)	/* Prescalar Rate Selection */
51 #define		AT91_ADC_PRESCAL_9G45	(0xff << 8)
52 #define			AT91_ADC_PRESCAL_(x)	((x) << 8)
53 #define		AT91_ADC_STARTUP_9260	(0x1f << 16)	/* Startup Up Time */
54 #define		AT91_ADC_STARTUP_9G45	(0x7f << 16)
55 #define		AT91_ADC_STARTUP_9X5	(0xf << 16)
56 #define			AT91_ADC_STARTUP_(x)	((x) << 16)
57 #define		AT91_ADC_SHTIM		(0xf  << 24)	/* Sample & Hold Time */
58 #define			AT91_ADC_SHTIM_(x)	((x) << 24)
59 #define		AT91_ADC_PENDBC		(0x0f << 28)	/* Pen Debounce time */
60 #define			AT91_ADC_PENDBC_(x)	((x) << 28)
61 
62 #define AT91_ADC_TSR		0x0C
63 #define		AT91_ADC_TSR_SHTIM	(0xf  << 24)	/* Sample & Hold Time */
64 #define			AT91_ADC_TSR_SHTIM_(x)	((x) << 24)
65 
66 #define AT91_ADC_CHER		0x10		/* Channel Enable Register */
67 #define AT91_ADC_CHDR		0x14		/* Channel Disable Register */
68 #define AT91_ADC_CHSR		0x18		/* Channel Status Register */
69 #define		AT91_ADC_CH(n)		(1 << (n))	/* Channel Number */
70 
71 #define AT91_ADC_SR		0x1C		/* Status Register */
72 #define		AT91_ADC_EOC(n)		(1 << (n))	/* End of Conversion on Channel N */
73 #define		AT91_ADC_OVRE(n)	(1 << ((n) + 8))/* Overrun Error on Channel N */
74 #define		AT91_ADC_DRDY		(1 << 16)	/* Data Ready */
75 #define		AT91_ADC_GOVRE		(1 << 17)	/* General Overrun Error */
76 #define		AT91_ADC_ENDRX		(1 << 18)	/* End of RX Buffer */
77 #define		AT91_ADC_RXFUFF		(1 << 19)	/* RX Buffer Full */
78 
79 #define AT91_ADC_SR_9X5		0x30		/* Status Register for 9x5 */
80 #define		AT91_ADC_SR_DRDY_9X5	(1 << 24)	/* Data Ready */
81 
82 #define AT91_ADC_LCDR		0x20		/* Last Converted Data Register */
83 #define		AT91_ADC_LDATA		(0x3ff)
84 
85 #define AT91_ADC_IER		0x24		/* Interrupt Enable Register */
86 #define AT91_ADC_IDR		0x28		/* Interrupt Disable Register */
87 #define AT91_ADC_IMR		0x2C		/* Interrupt Mask Register */
88 #define		AT91RL_ADC_IER_PEN	(1 << 20)
89 #define		AT91RL_ADC_IER_NOPEN	(1 << 21)
90 #define		AT91_ADC_IER_PEN	(1 << 29)
91 #define		AT91_ADC_IER_NOPEN	(1 << 30)
92 #define		AT91_ADC_IER_XRDY	(1 << 20)
93 #define		AT91_ADC_IER_YRDY	(1 << 21)
94 #define		AT91_ADC_IER_PRDY	(1 << 22)
95 #define		AT91_ADC_ISR_PENS	(1 << 31)
96 
97 #define AT91_ADC_CHR(n)		(0x30 + ((n) * 4))	/* Channel Data Register N */
98 #define		AT91_ADC_DATA		(0x3ff)
99 
100 #define AT91_ADC_CDR0_9X5	(0x50)			/* Channel Data Register 0 for 9X5 */
101 
102 #define AT91_ADC_ACR		0x94	/* Analog Control Register */
103 #define		AT91_ADC_ACR_PENDETSENS	(0x3 << 0)	/* pull-up resistor */
104 
105 #define AT91_ADC_TSMR		0xB0
106 #define		AT91_ADC_TSMR_TSMODE	(3 << 0)	/* Touch Screen Mode */
107 #define			AT91_ADC_TSMR_TSMODE_NONE		(0 << 0)
108 #define			AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS	(1 << 0)
109 #define			AT91_ADC_TSMR_TSMODE_4WIRE_PRESS	(2 << 0)
110 #define			AT91_ADC_TSMR_TSMODE_5WIRE		(3 << 0)
111 #define		AT91_ADC_TSMR_TSAV	(3 << 4)	/* Averages samples */
112 #define			AT91_ADC_TSMR_TSAV_(x)		((x) << 4)
113 #define		AT91_ADC_TSMR_SCTIM	(0x0f << 16)	/* Switch closure time */
114 #define			AT91_ADC_TSMR_SCTIM_(x)		((x) << 16)
115 #define		AT91_ADC_TSMR_PENDBC	(0x0f << 28)	/* Pen Debounce time */
116 #define			AT91_ADC_TSMR_PENDBC_(x)	((x) << 28)
117 #define		AT91_ADC_TSMR_NOTSDMA	(1 << 22)	/* No Touchscreen DMA */
118 #define		AT91_ADC_TSMR_PENDET_DIS	(0 << 24)	/* Pen contact detection disable */
119 #define		AT91_ADC_TSMR_PENDET_ENA	(1 << 24)	/* Pen contact detection enable */
120 
121 #define AT91_ADC_TSXPOSR	0xB4
122 #define AT91_ADC_TSYPOSR	0xB8
123 #define AT91_ADC_TSPRESSR	0xBC
124 
125 #define AT91_ADC_TRGR_9260	AT91_ADC_MR
126 #define AT91_ADC_TRGR_9G45	0x08
127 #define AT91_ADC_TRGR_9X5	0xC0
128 
129 /* Trigger Register bit field */
130 #define		AT91_ADC_TRGR_TRGPER	(0xffff << 16)
131 #define			AT91_ADC_TRGR_TRGPER_(x)	((x) << 16)
132 #define		AT91_ADC_TRGR_TRGMOD	(0x7 << 0)
133 #define			AT91_ADC_TRGR_NONE		(0 << 0)
134 #define			AT91_ADC_TRGR_MOD_PERIOD_TRIG	(5 << 0)
135 
136 #define AT91_ADC_CHAN(st, ch) \
137 	(st->registers->channel_base + (ch * 4))
138 #define at91_adc_readl(st, reg) \
139 	(readl_relaxed(st->reg_base + reg))
140 #define at91_adc_writel(st, reg, val) \
141 	(writel_relaxed(val, st->reg_base + reg))
142 
143 #define DRIVER_NAME		"at91_adc"
144 #define MAX_POS_BITS		12
145 
146 #define TOUCH_SAMPLE_PERIOD_US		2000	/* 2ms */
147 #define TOUCH_PEN_DETECT_DEBOUNCE_US	200
148 
149 #define MAX_RLPOS_BITS         10
150 #define TOUCH_SAMPLE_PERIOD_US_RL      10000   /* 10ms, the SoC can't keep up with 2ms */
151 #define TOUCH_SHTIM                    0xa
152 #define TOUCH_SCTIM_US		10		/* 10us for the Touchscreen Switches Closure Time */
153 
154 enum atmel_adc_ts_type {
155 	ATMEL_ADC_TOUCHSCREEN_NONE = 0,
156 	ATMEL_ADC_TOUCHSCREEN_4WIRE = 4,
157 	ATMEL_ADC_TOUCHSCREEN_5WIRE = 5,
158 };
159 
160 /**
161  * struct at91_adc_trigger - description of triggers
162  * @name:		name of the trigger advertised to the user
163  * @value:		value to set in the ADC's trigger setup register
164  *			to enable the trigger
165  * @is_external:	Does the trigger rely on an external pin?
166  */
167 struct at91_adc_trigger {
168 	const char	*name;
169 	u8		value;
170 	bool		is_external;
171 };
172 
173 /**
174  * struct at91_adc_reg_desc - Various information relative to registers
175  * @channel_base:	Base offset for the channel data registers
176  * @drdy_mask:		Mask of the DRDY field in the relevant registers
177  *			(Interruptions registers mostly)
178  * @status_register:	Offset of the Interrupt Status Register
179  * @trigger_register:	Offset of the Trigger setup register
180  * @mr_prescal_mask:	Mask of the PRESCAL field in the adc MR register
181  * @mr_startup_mask:	Mask of the STARTUP field in the adc MR register
182  */
183 struct at91_adc_reg_desc {
184 	u8	channel_base;
185 	u32	drdy_mask;
186 	u8	status_register;
187 	u8	trigger_register;
188 	u32	mr_prescal_mask;
189 	u32	mr_startup_mask;
190 };
191 
192 struct at91_adc_caps {
193 	bool	has_ts;		/* Support touch screen */
194 	bool	has_tsmr;	/* only at91sam9x5, sama5d3 have TSMR reg */
195 	/*
196 	 * Numbers of sampling data will be averaged. Can be 0~3.
197 	 * Hardware can average (2 ^ ts_filter_average) sample data.
198 	 */
199 	u8	ts_filter_average;
200 	/* Pen Detection input pull-up resistor, can be 0~3 */
201 	u8	ts_pen_detect_sensitivity;
202 
203 	/* startup time calculate function */
204 	u32 (*calc_startup_ticks)(u32 startup_time, u32 adc_clk_khz);
205 
206 	u8	num_channels;
207 
208 	u8	low_res_bits;
209 	u8	high_res_bits;
210 	u32	trigger_number;
211 	const struct at91_adc_trigger *triggers;
212 	struct at91_adc_reg_desc registers;
213 };
214 
215 struct at91_adc_state {
216 	struct clk		*adc_clk;
217 	u16			*buffer;
218 	unsigned long		channels_mask;
219 	struct clk		*clk;
220 	bool			done;
221 	int			irq;
222 	u16			last_value;
223 	int			chnb;
224 	struct mutex		lock;
225 	u8			num_channels;
226 	void __iomem		*reg_base;
227 	const struct at91_adc_reg_desc *registers;
228 	u32			startup_time;
229 	u8			sample_hold_time;
230 	bool			sleep_mode;
231 	struct iio_trigger	**trig;
232 	bool			use_external;
233 	u32			vref_mv;
234 	u32			res;		/* resolution used for conversions */
235 	wait_queue_head_t	wq_data_avail;
236 	const struct at91_adc_caps	*caps;
237 
238 	/*
239 	 * Following ADC channels are shared by touchscreen:
240 	 *
241 	 * CH0 -- Touch screen XP/UL
242 	 * CH1 -- Touch screen XM/UR
243 	 * CH2 -- Touch screen YP/LL
244 	 * CH3 -- Touch screen YM/Sense
245 	 * CH4 -- Touch screen LR(5-wire only)
246 	 *
247 	 * The bitfields below represents the reserved channel in the
248 	 * touchscreen mode.
249 	 */
250 #define CHAN_MASK_TOUCHSCREEN_4WIRE	(0xf << 0)
251 #define CHAN_MASK_TOUCHSCREEN_5WIRE	(0x1f << 0)
252 	enum atmel_adc_ts_type	touchscreen_type;
253 	struct input_dev	*ts_input;
254 
255 	u16			ts_sample_period_val;
256 	u32			ts_pressure_threshold;
257 	u16			ts_pendbc;
258 
259 	bool			ts_bufferedmeasure;
260 	u32			ts_prev_absx;
261 	u32			ts_prev_absy;
262 };
263 
264 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
265 {
266 	struct iio_poll_func *pf = p;
267 	struct iio_dev *idev = pf->indio_dev;
268 	struct at91_adc_state *st = iio_priv(idev);
269 	struct iio_chan_spec const *chan;
270 	int i, j = 0;
271 
272 	iio_for_each_active_channel(idev, i) {
273 		chan = idev->channels + i;
274 		st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, chan->channel));
275 		j++;
276 	}
277 
278 	iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
279 
280 	iio_trigger_notify_done(idev->trig);
281 
282 	/* Needed to ACK the DRDY interruption */
283 	at91_adc_readl(st, AT91_ADC_LCDR);
284 
285 	enable_irq(st->irq);
286 
287 	return IRQ_HANDLED;
288 }
289 
290 /* Handler for classic adc channel eoc trigger */
291 static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
292 {
293 	struct at91_adc_state *st = iio_priv(idev);
294 
295 	if (iio_buffer_enabled(idev)) {
296 		disable_irq_nosync(irq);
297 		iio_trigger_poll(idev->trig);
298 	} else {
299 		st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
300 		/* Needed to ACK the DRDY interruption */
301 		at91_adc_readl(st, AT91_ADC_LCDR);
302 		st->done = true;
303 		wake_up_interruptible(&st->wq_data_avail);
304 	}
305 }
306 
307 static void at91_ts_sample(struct iio_dev *idev)
308 {
309 	struct at91_adc_state *st = iio_priv(idev);
310 	unsigned int xscale, yscale, reg, z1, z2;
311 	unsigned int x, y, pres, xpos, ypos;
312 	unsigned int rxp = 1;
313 	unsigned int factor = 1000;
314 
315 	unsigned int xyz_mask_bits = st->res;
316 	unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
317 
318 	/* calculate position */
319 	/* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
320 	reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
321 	xpos = reg & xyz_mask;
322 	x = (xpos << MAX_POS_BITS) - xpos;
323 	xscale = (reg >> 16) & xyz_mask;
324 	if (xscale == 0) {
325 		dev_err(&idev->dev, "Error: xscale == 0!\n");
326 		return;
327 	}
328 	x /= xscale;
329 
330 	/* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
331 	reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
332 	ypos = reg & xyz_mask;
333 	y = (ypos << MAX_POS_BITS) - ypos;
334 	yscale = (reg >> 16) & xyz_mask;
335 	if (yscale == 0) {
336 		dev_err(&idev->dev, "Error: yscale == 0!\n");
337 		return;
338 	}
339 	y /= yscale;
340 
341 	/* calculate the pressure */
342 	reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
343 	z1 = reg & xyz_mask;
344 	z2 = (reg >> 16) & xyz_mask;
345 
346 	if (z1 != 0)
347 		pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
348 			/ factor;
349 	else
350 		pres = st->ts_pressure_threshold;	/* no pen contacted */
351 
352 	dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
353 				xpos, xscale, ypos, yscale, z1, z2, pres);
354 
355 	if (pres < st->ts_pressure_threshold) {
356 		dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
357 					x, y, pres / factor);
358 		input_report_abs(st->ts_input, ABS_X, x);
359 		input_report_abs(st->ts_input, ABS_Y, y);
360 		input_report_abs(st->ts_input, ABS_PRESSURE, pres);
361 		input_report_key(st->ts_input, BTN_TOUCH, 1);
362 		input_sync(st->ts_input);
363 	} else {
364 		dev_dbg(&idev->dev, "pressure too low: not reporting\n");
365 	}
366 }
367 
368 static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
369 {
370 	struct iio_dev *idev = private;
371 	struct at91_adc_state *st = iio_priv(idev);
372 	u32 status = at91_adc_readl(st, st->registers->status_register);
373 	unsigned int reg;
374 
375 	status &= at91_adc_readl(st, AT91_ADC_IMR);
376 	if (status & GENMASK(st->num_channels - 1, 0))
377 		handle_adc_eoc_trigger(irq, idev);
378 
379 	if (status & AT91RL_ADC_IER_PEN) {
380 		/* Disabling pen debounce is required to get a NOPEN irq */
381 		reg = at91_adc_readl(st, AT91_ADC_MR);
382 		reg &= ~AT91_ADC_PENDBC;
383 		at91_adc_writel(st, AT91_ADC_MR, reg);
384 
385 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
386 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
387 				| AT91_ADC_EOC(3));
388 		/* Set up period trigger for sampling */
389 		at91_adc_writel(st, st->registers->trigger_register,
390 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
391 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
392 	} else if (status & AT91RL_ADC_IER_NOPEN) {
393 		reg = at91_adc_readl(st, AT91_ADC_MR);
394 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
395 		at91_adc_writel(st, AT91_ADC_MR, reg);
396 		at91_adc_writel(st, st->registers->trigger_register,
397 			AT91_ADC_TRGR_NONE);
398 
399 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
400 				| AT91_ADC_EOC(3));
401 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
402 		st->ts_bufferedmeasure = false;
403 		input_report_key(st->ts_input, BTN_TOUCH, 0);
404 		input_sync(st->ts_input);
405 	} else if (status & AT91_ADC_EOC(3) && st->ts_input) {
406 		/* Conversion finished and we've a touchscreen */
407 		if (st->ts_bufferedmeasure) {
408 			/*
409 			 * Last measurement is always discarded, since it can
410 			 * be erroneous.
411 			 * Always report previous measurement
412 			 */
413 			input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
414 			input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
415 			input_report_key(st->ts_input, BTN_TOUCH, 1);
416 			input_sync(st->ts_input);
417 		} else
418 			st->ts_bufferedmeasure = true;
419 
420 		/* Now make new measurement */
421 		st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
422 				   << MAX_RLPOS_BITS;
423 		st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
424 
425 		st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
426 				   << MAX_RLPOS_BITS;
427 		st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
428 	}
429 
430 	return IRQ_HANDLED;
431 }
432 
433 static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
434 {
435 	struct iio_dev *idev = private;
436 	struct at91_adc_state *st = iio_priv(idev);
437 	u32 status = at91_adc_readl(st, st->registers->status_register);
438 	const uint32_t ts_data_irq_mask =
439 		AT91_ADC_IER_XRDY |
440 		AT91_ADC_IER_YRDY |
441 		AT91_ADC_IER_PRDY;
442 
443 	if (status & GENMASK(st->num_channels - 1, 0))
444 		handle_adc_eoc_trigger(irq, idev);
445 
446 	if (status & AT91_ADC_IER_PEN) {
447 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
448 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
449 			ts_data_irq_mask);
450 		/* Set up period trigger for sampling */
451 		at91_adc_writel(st, st->registers->trigger_register,
452 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
453 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
454 	} else if (status & AT91_ADC_IER_NOPEN) {
455 		at91_adc_writel(st, st->registers->trigger_register, 0);
456 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
457 			ts_data_irq_mask);
458 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
459 
460 		input_report_key(st->ts_input, BTN_TOUCH, 0);
461 		input_sync(st->ts_input);
462 	} else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
463 		/* Now all touchscreen data is ready */
464 
465 		if (status & AT91_ADC_ISR_PENS) {
466 			/* validate data by pen contact */
467 			at91_ts_sample(idev);
468 		} else {
469 			/* triggered by event that is no pen contact, just read
470 			 * them to clean the interrupt and discard all.
471 			 */
472 			at91_adc_readl(st, AT91_ADC_TSXPOSR);
473 			at91_adc_readl(st, AT91_ADC_TSYPOSR);
474 			at91_adc_readl(st, AT91_ADC_TSPRESSR);
475 		}
476 	}
477 
478 	return IRQ_HANDLED;
479 }
480 
481 static int at91_adc_channel_init(struct iio_dev *idev)
482 {
483 	struct at91_adc_state *st = iio_priv(idev);
484 	struct iio_chan_spec *chan_array;
485 	int bit, idx = 0;
486 	unsigned long rsvd_mask = 0;
487 
488 	/* If touchscreen is enable, then reserve the adc channels */
489 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
490 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
491 	else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
492 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
493 
494 	/* set up the channel mask to reserve touchscreen channels */
495 	st->channels_mask &= ~rsvd_mask;
496 
497 	idev->num_channels = bitmap_weight(&st->channels_mask,
498 					   st->num_channels) + 1;
499 
500 	chan_array = devm_kzalloc(&idev->dev,
501 				  ((idev->num_channels + 1) *
502 					sizeof(struct iio_chan_spec)),
503 				  GFP_KERNEL);
504 
505 	if (!chan_array)
506 		return -ENOMEM;
507 
508 	for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
509 		struct iio_chan_spec *chan = chan_array + idx;
510 
511 		chan->type = IIO_VOLTAGE;
512 		chan->indexed = 1;
513 		chan->channel = bit;
514 		chan->scan_index = idx;
515 		chan->scan_type.sign = 'u';
516 		chan->scan_type.realbits = st->res;
517 		chan->scan_type.storagebits = 16;
518 		chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
519 		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
520 		idx++;
521 	}
522 
523 	chan_array[idx] = IIO_CHAN_SOFT_TIMESTAMP(idx);
524 
525 	idev->channels = chan_array;
526 	return idev->num_channels;
527 }
528 
529 static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
530 					     const struct at91_adc_trigger *triggers,
531 					     const char *trigger_name)
532 {
533 	struct at91_adc_state *st = iio_priv(idev);
534 	int i;
535 
536 	for (i = 0; i < st->caps->trigger_number; i++) {
537 		char *name __free(kfree) = kasprintf(GFP_KERNEL, "%s-dev%d-%s",
538 						     idev->name,
539 						     iio_device_id(idev),
540 						     triggers[i].name);
541 		if (!name)
542 			return -ENOMEM;
543 
544 		if (strcmp(trigger_name, name) == 0) {
545 			if (triggers[i].value == 0)
546 				return -EINVAL;
547 			return triggers[i].value;
548 		}
549 	}
550 
551 	return -EINVAL;
552 }
553 
554 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
555 {
556 	struct iio_dev *idev = iio_trigger_get_drvdata(trig);
557 	struct at91_adc_state *st = iio_priv(idev);
558 	const struct at91_adc_reg_desc *reg = st->registers;
559 	u32 status = at91_adc_readl(st, reg->trigger_register);
560 	int value;
561 	u8 bit;
562 
563 	value = at91_adc_get_trigger_value_by_name(idev,
564 						   st->caps->triggers,
565 						   idev->trig->name);
566 	if (value < 0)
567 		return value;
568 
569 	if (state) {
570 		st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
571 		if (st->buffer == NULL)
572 			return -ENOMEM;
573 
574 		at91_adc_writel(st, reg->trigger_register,
575 				status | value);
576 
577 		for_each_set_bit(bit, idev->active_scan_mask,
578 				 st->num_channels) {
579 			struct iio_chan_spec const *chan = idev->channels + bit;
580 			at91_adc_writel(st, AT91_ADC_CHER,
581 					AT91_ADC_CH(chan->channel));
582 		}
583 
584 		at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
585 
586 	} else {
587 		at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
588 
589 		at91_adc_writel(st, reg->trigger_register,
590 				status & ~value);
591 
592 		for_each_set_bit(bit, idev->active_scan_mask,
593 				 st->num_channels) {
594 			struct iio_chan_spec const *chan = idev->channels + bit;
595 			at91_adc_writel(st, AT91_ADC_CHDR,
596 					AT91_ADC_CH(chan->channel));
597 		}
598 		kfree(st->buffer);
599 	}
600 
601 	return 0;
602 }
603 
604 static const struct iio_trigger_ops at91_adc_trigger_ops = {
605 	.set_trigger_state = &at91_adc_configure_trigger,
606 };
607 
608 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
609 						     const struct at91_adc_trigger *trigger)
610 {
611 	struct iio_trigger *trig;
612 	int ret;
613 
614 	trig = iio_trigger_alloc(idev->dev.parent, "%s-dev%d-%s", idev->name,
615 				 iio_device_id(idev), trigger->name);
616 	if (trig == NULL)
617 		return NULL;
618 
619 	iio_trigger_set_drvdata(trig, idev);
620 	trig->ops = &at91_adc_trigger_ops;
621 
622 	ret = iio_trigger_register(trig);
623 	if (ret) {
624 		iio_trigger_free(trig);
625 		return NULL;
626 	}
627 
628 	return trig;
629 }
630 
631 static int at91_adc_trigger_init(struct iio_dev *idev)
632 {
633 	struct at91_adc_state *st = iio_priv(idev);
634 	int i, ret;
635 
636 	st->trig = devm_kcalloc(&idev->dev,
637 				st->caps->trigger_number, sizeof(*st->trig),
638 				GFP_KERNEL);
639 
640 	if (st->trig == NULL) {
641 		ret = -ENOMEM;
642 		goto error_ret;
643 	}
644 
645 	for (i = 0; i < st->caps->trigger_number; i++) {
646 		if (st->caps->triggers[i].is_external && !(st->use_external))
647 			continue;
648 
649 		st->trig[i] = at91_adc_allocate_trigger(idev,
650 							st->caps->triggers + i);
651 		if (st->trig[i] == NULL) {
652 			dev_err(&idev->dev,
653 				"Could not allocate trigger %d\n", i);
654 			ret = -ENOMEM;
655 			goto error_trigger;
656 		}
657 	}
658 
659 	return 0;
660 
661 error_trigger:
662 	for (i--; i >= 0; i--) {
663 		iio_trigger_unregister(st->trig[i]);
664 		iio_trigger_free(st->trig[i]);
665 	}
666 error_ret:
667 	return ret;
668 }
669 
670 static void at91_adc_trigger_remove(struct iio_dev *idev)
671 {
672 	struct at91_adc_state *st = iio_priv(idev);
673 	int i;
674 
675 	for (i = 0; i < st->caps->trigger_number; i++) {
676 		iio_trigger_unregister(st->trig[i]);
677 		iio_trigger_free(st->trig[i]);
678 	}
679 }
680 
681 static int at91_adc_buffer_init(struct iio_dev *idev)
682 {
683 	return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
684 		&at91_adc_trigger_handler, NULL);
685 }
686 
687 static void at91_adc_buffer_remove(struct iio_dev *idev)
688 {
689 	iio_triggered_buffer_cleanup(idev);
690 }
691 
692 static int at91_adc_read_raw(struct iio_dev *idev,
693 			     struct iio_chan_spec const *chan,
694 			     int *val, int *val2, long mask)
695 {
696 	struct at91_adc_state *st = iio_priv(idev);
697 	int ret;
698 
699 	switch (mask) {
700 	case IIO_CHAN_INFO_RAW:
701 		mutex_lock(&st->lock);
702 
703 		st->chnb = chan->channel;
704 		at91_adc_writel(st, AT91_ADC_CHER,
705 				AT91_ADC_CH(chan->channel));
706 		at91_adc_writel(st, AT91_ADC_IER, BIT(chan->channel));
707 		at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
708 
709 		ret = wait_event_interruptible_timeout(st->wq_data_avail,
710 						       st->done,
711 						       msecs_to_jiffies(1000));
712 
713 		/* Disable interrupts, regardless if adc conversion was
714 		 * successful or not
715 		 */
716 		at91_adc_writel(st, AT91_ADC_CHDR,
717 				AT91_ADC_CH(chan->channel));
718 		at91_adc_writel(st, AT91_ADC_IDR, BIT(chan->channel));
719 
720 		if (ret > 0) {
721 			/* a valid conversion took place */
722 			*val = st->last_value;
723 			st->last_value = 0;
724 			st->done = false;
725 			ret = IIO_VAL_INT;
726 		} else if (ret == 0) {
727 			/* conversion timeout */
728 			dev_err(&idev->dev, "ADC Channel %d timeout.\n",
729 				chan->channel);
730 			ret = -ETIMEDOUT;
731 		}
732 
733 		mutex_unlock(&st->lock);
734 		return ret;
735 
736 	case IIO_CHAN_INFO_SCALE:
737 		*val = st->vref_mv;
738 		*val2 = chan->scan_type.realbits;
739 		return IIO_VAL_FRACTIONAL_LOG2;
740 	default:
741 		break;
742 	}
743 	return -EINVAL;
744 }
745 
746 
747 static u32 calc_startup_ticks_9260(u32 startup_time, u32 adc_clk_khz)
748 {
749 	/*
750 	 * Number of ticks needed to cover the startup time of the ADC
751 	 * as defined in the electrical characteristics of the board,
752 	 * divided by 8. The formula thus is :
753 	 *   Startup Time = (ticks + 1) * 8 / ADC Clock
754 	 */
755 	return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
756 }
757 
758 static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz)
759 {
760 	/*
761 	 * For sama5d3x and at91sam9x5, the formula changes to:
762 	 * Startup Time = <lookup_table_value> / ADC Clock
763 	 */
764 	static const int startup_lookup[] = {
765 		0,   8,   16,  24,
766 		64,  80,  96,  112,
767 		512, 576, 640, 704,
768 		768, 832, 896, 960
769 		};
770 	int i, size = ARRAY_SIZE(startup_lookup);
771 	unsigned int ticks;
772 
773 	ticks = startup_time * adc_clk_khz / 1000;
774 	for (i = 0; i < size; i++)
775 		if (ticks < startup_lookup[i])
776 			break;
777 
778 	ticks = i;
779 	if (ticks == size)
780 		/* Reach the end of lookup table */
781 		ticks = size - 1;
782 
783 	return ticks;
784 }
785 
786 static int at91_adc_probe_dt_ts(struct device_node *node,
787 	struct at91_adc_state *st, struct device *dev)
788 {
789 	int ret;
790 	u32 prop;
791 
792 	ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
793 	if (ret) {
794 		dev_info(dev, "ADC Touch screen is disabled.\n");
795 		return 0;
796 	}
797 
798 	switch (prop) {
799 	case 4:
800 	case 5:
801 		st->touchscreen_type = prop;
802 		break;
803 	default:
804 		dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
805 		return -EINVAL;
806 	}
807 
808 	if (!st->caps->has_tsmr)
809 		return 0;
810 	prop = 0;
811 	of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
812 	st->ts_pressure_threshold = prop;
813 	if (st->ts_pressure_threshold) {
814 		return 0;
815 	} else {
816 		dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
817 		return -EINVAL;
818 	}
819 }
820 
821 static const struct iio_info at91_adc_info = {
822 	.read_raw = &at91_adc_read_raw,
823 };
824 
825 /* Touchscreen related functions */
826 static int atmel_ts_open(struct input_dev *dev)
827 {
828 	struct at91_adc_state *st = input_get_drvdata(dev);
829 
830 	if (st->caps->has_tsmr)
831 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
832 	else
833 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
834 	return 0;
835 }
836 
837 static void atmel_ts_close(struct input_dev *dev)
838 {
839 	struct at91_adc_state *st = input_get_drvdata(dev);
840 
841 	if (st->caps->has_tsmr)
842 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
843 	else
844 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
845 }
846 
847 static int at91_ts_hw_init(struct iio_dev *idev, u32 adc_clk_khz)
848 {
849 	struct at91_adc_state *st = iio_priv(idev);
850 	u32 reg = 0;
851 	u32 tssctim = 0;
852 	int i = 0;
853 
854 	/* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
855 	 * pen detect noise.
856 	 * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
857 	 */
858 	st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
859 				 1000, 1);
860 
861 	while (st->ts_pendbc >> ++i)
862 		;	/* Empty! Find the shift offset */
863 	if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
864 		st->ts_pendbc = i;
865 	else
866 		st->ts_pendbc = i - 1;
867 
868 	if (!st->caps->has_tsmr) {
869 		reg = at91_adc_readl(st, AT91_ADC_MR);
870 		reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
871 
872 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
873 		at91_adc_writel(st, AT91_ADC_MR, reg);
874 
875 		reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
876 		at91_adc_writel(st, AT91_ADC_TSR, reg);
877 
878 		st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
879 						    adc_clk_khz / 1000) - 1, 1);
880 
881 		return 0;
882 	}
883 
884 	/* Touchscreen Switches Closure time needed for allowing the value to
885 	 * stabilize.
886 	 * Switch Closure Time = (TSSCTIM * 4) ADCClock periods
887 	 */
888 	tssctim = DIV_ROUND_UP(TOUCH_SCTIM_US * adc_clk_khz / 1000, 4);
889 	dev_dbg(&idev->dev, "adc_clk at: %d KHz, tssctim at: %d\n",
890 		adc_clk_khz, tssctim);
891 
892 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
893 		reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
894 	else
895 		reg = AT91_ADC_TSMR_TSMODE_5WIRE;
896 
897 	reg |= AT91_ADC_TSMR_SCTIM_(tssctim) & AT91_ADC_TSMR_SCTIM;
898 	reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
899 	       & AT91_ADC_TSMR_TSAV;
900 	reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
901 	reg |= AT91_ADC_TSMR_NOTSDMA;
902 	reg |= AT91_ADC_TSMR_PENDET_ENA;
903 	reg |= 0x03 << 8;	/* TSFREQ, needs to be bigger than TSAV */
904 
905 	at91_adc_writel(st, AT91_ADC_TSMR, reg);
906 
907 	/* Change adc internal resistor value for better pen detection,
908 	 * default value is 100 kOhm.
909 	 * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
910 	 * option only available on ES2 and higher
911 	 */
912 	at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
913 			& AT91_ADC_ACR_PENDETSENS);
914 
915 	/* Sample Period Time = (TRGPER + 1) / ADCClock */
916 	st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
917 			adc_clk_khz / 1000) - 1, 1);
918 
919 	return 0;
920 }
921 
922 static int at91_ts_register(struct iio_dev *idev,
923 		struct platform_device *pdev)
924 {
925 	struct at91_adc_state *st = iio_priv(idev);
926 	struct input_dev *input;
927 	int ret;
928 
929 	input = input_allocate_device();
930 	if (!input) {
931 		dev_err(&idev->dev, "Failed to allocate TS device!\n");
932 		return -ENOMEM;
933 	}
934 
935 	input->name = DRIVER_NAME;
936 	input->id.bustype = BUS_HOST;
937 	input->dev.parent = &pdev->dev;
938 	input->open = atmel_ts_open;
939 	input->close = atmel_ts_close;
940 
941 	__set_bit(EV_ABS, input->evbit);
942 	__set_bit(EV_KEY, input->evbit);
943 	__set_bit(BTN_TOUCH, input->keybit);
944 	if (st->caps->has_tsmr) {
945 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
946 				     0, 0);
947 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
948 				     0, 0);
949 		input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
950 	} else {
951 		if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
952 			dev_err(&pdev->dev,
953 				"This touchscreen controller only support 4 wires\n");
954 			ret = -EINVAL;
955 			goto err;
956 		}
957 
958 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
959 				     0, 0);
960 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
961 				     0, 0);
962 	}
963 
964 	st->ts_input = input;
965 	input_set_drvdata(input, st);
966 
967 	ret = input_register_device(input);
968 	if (ret)
969 		goto err;
970 
971 	return ret;
972 
973 err:
974 	input_free_device(input);
975 	return ret;
976 }
977 
978 static void at91_ts_unregister(struct at91_adc_state *st)
979 {
980 	input_unregister_device(st->ts_input);
981 }
982 
983 static int at91_adc_probe(struct platform_device *pdev)
984 {
985 	unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
986 	struct device_node *node = pdev->dev.of_node;
987 	int ret;
988 	struct iio_dev *idev;
989 	struct at91_adc_state *st;
990 	u32 reg, prop;
991 	char *s;
992 
993 	idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
994 	if (!idev)
995 		return -ENOMEM;
996 
997 	st = iio_priv(idev);
998 
999 	st->caps = of_device_get_match_data(&pdev->dev);
1000 
1001 	st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
1002 
1003 	if (of_property_read_u32(node, "atmel,adc-channels-used", &prop))
1004 		return dev_err_probe(&idev->dev, -EINVAL,
1005 				     "Missing adc-channels-used property in the DT.\n");
1006 	st->channels_mask = prop;
1007 
1008 	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
1009 
1010 	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop))
1011 		return dev_err_probe(&idev->dev, -EINVAL,
1012 				     "Missing adc-startup-time property in the DT.\n");
1013 	st->startup_time = prop;
1014 
1015 	prop = 0;
1016 	of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
1017 	st->sample_hold_time = prop;
1018 
1019 	if (of_property_read_u32(node, "atmel,adc-vref", &prop))
1020 		return dev_err_probe(&idev->dev, -EINVAL,
1021 				     "Missing adc-vref property in the DT.\n");
1022 	st->vref_mv = prop;
1023 
1024 	st->res = st->caps->high_res_bits;
1025 	if (st->caps->low_res_bits &&
1026 	    !of_property_read_string(node, "atmel,adc-use-res", (const char **)&s)
1027 	    && !strcmp(s, "lowres"))
1028 		st->res = st->caps->low_res_bits;
1029 
1030 	dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
1031 
1032 	st->registers = &st->caps->registers;
1033 	st->num_channels = st->caps->num_channels;
1034 
1035 	/* Check if touchscreen is supported. */
1036 	if (st->caps->has_ts) {
1037 		ret = at91_adc_probe_dt_ts(node, st, &idev->dev);
1038 		if (ret)
1039 			return ret;
1040 	}
1041 
1042 	platform_set_drvdata(pdev, idev);
1043 
1044 	idev->name = dev_name(&pdev->dev);
1045 	idev->modes = INDIO_DIRECT_MODE;
1046 	idev->info = &at91_adc_info;
1047 
1048 	st->irq = platform_get_irq(pdev, 0);
1049 	if (st->irq < 0)
1050 		return -ENODEV;
1051 
1052 	st->reg_base = devm_platform_ioremap_resource(pdev, 0);
1053 	if (IS_ERR(st->reg_base))
1054 		return PTR_ERR(st->reg_base);
1055 
1056 	/*
1057 	 * Disable all IRQs before setting up the handler
1058 	 */
1059 	at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
1060 	at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
1061 
1062 	if (st->caps->has_tsmr)
1063 		ret = devm_request_irq(&pdev->dev, st->irq,
1064 				       at91_adc_9x5_interrupt, 0,
1065 				       pdev->dev.driver->name, idev);
1066 	else
1067 		ret = devm_request_irq(&pdev->dev, st->irq,
1068 				       at91_adc_rl_interrupt, 0,
1069 				       pdev->dev.driver->name, idev);
1070 	if (ret)
1071 		return dev_err_probe(&pdev->dev, ret,
1072 				     "Failed to allocate IRQ.\n");
1073 
1074 	st->clk = devm_clk_get_enabled(&pdev->dev, "adc_clk");
1075 	if (IS_ERR(st->clk))
1076 		return dev_err_probe(&pdev->dev, PTR_ERR(st->clk),
1077 				     "Could not prepare or enable the clock.\n");
1078 
1079 	st->adc_clk = devm_clk_get_enabled(&pdev->dev, "adc_op_clk");
1080 	if (IS_ERR(st->adc_clk))
1081 		return dev_err_probe(&pdev->dev, PTR_ERR(st->adc_clk),
1082 				     "Could not prepare or enable the ADC clock.\n");
1083 
1084 	/*
1085 	 * Prescaler rate computation using the formula from the Atmel's
1086 	 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
1087 	 * specified by the electrical characteristics of the board.
1088 	 */
1089 	mstrclk = clk_get_rate(st->clk);
1090 	adc_clk = clk_get_rate(st->adc_clk);
1091 	adc_clk_khz = adc_clk / 1000;
1092 
1093 	dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
1094 		mstrclk, adc_clk);
1095 
1096 	prsc = (mstrclk / (2 * adc_clk)) - 1;
1097 
1098 	if (!st->startup_time)
1099 		return dev_err_probe(&pdev->dev, -EINVAL,
1100 				     "No startup time available.\n");
1101 	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
1102 
1103 	/*
1104 	 * a minimal Sample and Hold Time is necessary for the ADC to guarantee
1105 	 * the best converted final value between two channels selection
1106 	 * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
1107 	 */
1108 	if (st->sample_hold_time > 0)
1109 		shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000)
1110 				 - 1, 1);
1111 	else
1112 		shtim = 0;
1113 
1114 	reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
1115 	reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
1116 	if (st->res == st->caps->low_res_bits)
1117 		reg |= AT91_ADC_LOWRES;
1118 	if (st->sleep_mode)
1119 		reg |= AT91_ADC_SLEEP;
1120 	reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
1121 	at91_adc_writel(st, AT91_ADC_MR, reg);
1122 
1123 	/* Setup the ADC channels available on the board */
1124 	ret = at91_adc_channel_init(idev);
1125 	if (ret < 0)
1126 		return dev_err_probe(&pdev->dev, ret,
1127 				     "Couldn't initialize the channels.\n");
1128 
1129 	init_waitqueue_head(&st->wq_data_avail);
1130 	mutex_init(&st->lock);
1131 
1132 	/*
1133 	 * Since touch screen will set trigger register as period trigger. So
1134 	 * when touch screen is enabled, then we have to disable hardware
1135 	 * trigger for classic adc.
1136 	 */
1137 	if (!st->touchscreen_type) {
1138 		ret = at91_adc_buffer_init(idev);
1139 		if (ret < 0)
1140 			return dev_err_probe(&pdev->dev, ret,
1141 					     "Couldn't initialize the buffer.\n");
1142 
1143 		ret = at91_adc_trigger_init(idev);
1144 		if (ret < 0) {
1145 			dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
1146 			at91_adc_buffer_remove(idev);
1147 			return ret;
1148 		}
1149 	} else {
1150 		ret = at91_ts_register(idev, pdev);
1151 		if (ret)
1152 			return ret;
1153 
1154 		at91_ts_hw_init(idev, adc_clk_khz);
1155 	}
1156 
1157 	ret = iio_device_register(idev);
1158 	if (ret < 0) {
1159 		dev_err(&pdev->dev, "Couldn't register the device.\n");
1160 		goto error_iio_device_register;
1161 	}
1162 
1163 	return 0;
1164 
1165 error_iio_device_register:
1166 	if (!st->touchscreen_type) {
1167 		at91_adc_trigger_remove(idev);
1168 		at91_adc_buffer_remove(idev);
1169 	} else {
1170 		at91_ts_unregister(st);
1171 	}
1172 	return ret;
1173 }
1174 
1175 static void at91_adc_remove(struct platform_device *pdev)
1176 {
1177 	struct iio_dev *idev = platform_get_drvdata(pdev);
1178 	struct at91_adc_state *st = iio_priv(idev);
1179 
1180 	iio_device_unregister(idev);
1181 	if (!st->touchscreen_type) {
1182 		at91_adc_trigger_remove(idev);
1183 		at91_adc_buffer_remove(idev);
1184 	} else {
1185 		at91_ts_unregister(st);
1186 	}
1187 }
1188 
1189 static int at91_adc_suspend(struct device *dev)
1190 {
1191 	struct iio_dev *idev = dev_get_drvdata(dev);
1192 	struct at91_adc_state *st = iio_priv(idev);
1193 
1194 	pinctrl_pm_select_sleep_state(dev);
1195 	clk_disable_unprepare(st->clk);
1196 
1197 	return 0;
1198 }
1199 
1200 static int at91_adc_resume(struct device *dev)
1201 {
1202 	struct iio_dev *idev = dev_get_drvdata(dev);
1203 	struct at91_adc_state *st = iio_priv(idev);
1204 
1205 	clk_prepare_enable(st->clk);
1206 	pinctrl_pm_select_default_state(dev);
1207 
1208 	return 0;
1209 }
1210 
1211 static DEFINE_SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend,
1212 				at91_adc_resume);
1213 
1214 static const struct at91_adc_trigger at91sam9260_triggers[] = {
1215 	{ .name = "timer-counter-0", .value = 0x1 },
1216 	{ .name = "timer-counter-1", .value = 0x3 },
1217 	{ .name = "timer-counter-2", .value = 0x5 },
1218 	{ .name = "external", .value = 0xd, .is_external = true },
1219 };
1220 
1221 static const struct at91_adc_caps at91sam9260_caps = {
1222 	.calc_startup_ticks = calc_startup_ticks_9260,
1223 	.num_channels = 4,
1224 	.low_res_bits = 8,
1225 	.high_res_bits = 10,
1226 	.registers = {
1227 		.channel_base = AT91_ADC_CHR(0),
1228 		.drdy_mask = AT91_ADC_DRDY,
1229 		.status_register = AT91_ADC_SR,
1230 		.trigger_register = AT91_ADC_TRGR_9260,
1231 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1232 		.mr_startup_mask = AT91_ADC_STARTUP_9260,
1233 	},
1234 	.triggers = at91sam9260_triggers,
1235 	.trigger_number = ARRAY_SIZE(at91sam9260_triggers),
1236 };
1237 
1238 static const struct at91_adc_trigger at91sam9x5_triggers[] = {
1239 	{ .name = "external-rising", .value = 0x1, .is_external = true },
1240 	{ .name = "external-falling", .value = 0x2, .is_external = true },
1241 	{ .name = "external-any", .value = 0x3, .is_external = true },
1242 	{ .name = "continuous", .value = 0x6 },
1243 };
1244 
1245 static const struct at91_adc_caps at91sam9rl_caps = {
1246 	.has_ts = true,
1247 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1248 	.num_channels = 6,
1249 	.low_res_bits = 8,
1250 	.high_res_bits = 10,
1251 	.registers = {
1252 		.channel_base = AT91_ADC_CHR(0),
1253 		.drdy_mask = AT91_ADC_DRDY,
1254 		.status_register = AT91_ADC_SR,
1255 		.trigger_register = AT91_ADC_TRGR_9G45,
1256 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1257 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1258 	},
1259 	.triggers = at91sam9x5_triggers,
1260 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1261 };
1262 
1263 static const struct at91_adc_caps at91sam9g45_caps = {
1264 	.has_ts = true,
1265 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1266 	.num_channels = 8,
1267 	.low_res_bits = 8,
1268 	.high_res_bits = 10,
1269 	.registers = {
1270 		.channel_base = AT91_ADC_CHR(0),
1271 		.drdy_mask = AT91_ADC_DRDY,
1272 		.status_register = AT91_ADC_SR,
1273 		.trigger_register = AT91_ADC_TRGR_9G45,
1274 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1275 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1276 	},
1277 	.triggers = at91sam9x5_triggers,
1278 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1279 };
1280 
1281 static const struct at91_adc_caps at91sam9x5_caps = {
1282 	.has_ts = true,
1283 	.has_tsmr = true,
1284 	.ts_filter_average = 3,
1285 	.ts_pen_detect_sensitivity = 2,
1286 	.calc_startup_ticks = calc_startup_ticks_9x5,
1287 	.num_channels = 12,
1288 	.low_res_bits = 8,
1289 	.high_res_bits = 10,
1290 	.registers = {
1291 		.channel_base = AT91_ADC_CDR0_9X5,
1292 		.drdy_mask = AT91_ADC_SR_DRDY_9X5,
1293 		.status_register = AT91_ADC_SR_9X5,
1294 		.trigger_register = AT91_ADC_TRGR_9X5,
1295 		/* prescal mask is same as 9G45 */
1296 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1297 		.mr_startup_mask = AT91_ADC_STARTUP_9X5,
1298 	},
1299 	.triggers = at91sam9x5_triggers,
1300 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1301 };
1302 
1303 static const struct at91_adc_caps sama5d3_caps = {
1304 	.has_ts = true,
1305 	.has_tsmr = true,
1306 	.ts_filter_average = 3,
1307 	.ts_pen_detect_sensitivity = 2,
1308 	.calc_startup_ticks = calc_startup_ticks_9x5,
1309 	.num_channels = 12,
1310 	.low_res_bits = 0,
1311 	.high_res_bits = 12,
1312 	.registers = {
1313 		.channel_base = AT91_ADC_CDR0_9X5,
1314 		.drdy_mask = AT91_ADC_SR_DRDY_9X5,
1315 		.status_register = AT91_ADC_SR_9X5,
1316 		.trigger_register = AT91_ADC_TRGR_9X5,
1317 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1318 		.mr_startup_mask = AT91_ADC_STARTUP_9X5,
1319 	},
1320 	.triggers = at91sam9x5_triggers,
1321 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1322 };
1323 
1324 static const struct of_device_id at91_adc_dt_ids[] = {
1325 	{ .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
1326 	{ .compatible = "atmel,at91sam9rl-adc", .data = &at91sam9rl_caps },
1327 	{ .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
1328 	{ .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
1329 	{ .compatible = "atmel,sama5d3-adc", .data = &sama5d3_caps },
1330 	{ }
1331 };
1332 MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
1333 
1334 static struct platform_driver at91_adc_driver = {
1335 	.probe = at91_adc_probe,
1336 	.remove = at91_adc_remove,
1337 	.driver = {
1338 		   .name = DRIVER_NAME,
1339 		   .of_match_table = at91_adc_dt_ids,
1340 		   .pm = pm_sleep_ptr(&at91_adc_pm_ops),
1341 	},
1342 };
1343 
1344 module_platform_driver(at91_adc_driver);
1345 
1346 MODULE_LICENSE("GPL");
1347 MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
1348 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1349