xref: /linux/drivers/iio/adc/at91_adc.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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/clk.h>
11 #include <linux/err.h>
12 #include <linux/io.h>
13 #include <linux/input.h>
14 #include <linux/interrupt.h>
15 #include <linux/jiffies.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/wait.h>
23 
24 #include <linux/iio/iio.h>
25 #include <linux/iio/buffer.h>
26 #include <linux/iio/trigger.h>
27 #include <linux/iio/trigger_consumer.h>
28 #include <linux/iio/triggered_buffer.h>
29 #include <linux/pinctrl/consumer.h>
30 
31 /* Registers */
32 #define AT91_ADC_CR		0x00		/* Control Register */
33 #define		AT91_ADC_SWRST		(1 << 0)	/* Software Reset */
34 #define		AT91_ADC_START		(1 << 1)	/* Start Conversion */
35 
36 #define AT91_ADC_MR		0x04		/* Mode Register */
37 #define		AT91_ADC_TSAMOD		(3 << 0)	/* ADC mode */
38 #define		AT91_ADC_TSAMOD_ADC_ONLY_MODE		(0 << 0)	/* ADC Mode */
39 #define		AT91_ADC_TSAMOD_TS_ONLY_MODE		(1 << 0)	/* Touch Screen Only Mode */
40 #define		AT91_ADC_TRGEN		(1 << 0)	/* Trigger Enable */
41 #define		AT91_ADC_TRGSEL		(7 << 1)	/* Trigger Selection */
42 #define			AT91_ADC_TRGSEL_TC0		(0 << 1)
43 #define			AT91_ADC_TRGSEL_TC1		(1 << 1)
44 #define			AT91_ADC_TRGSEL_TC2		(2 << 1)
45 #define			AT91_ADC_TRGSEL_EXTERNAL	(6 << 1)
46 #define		AT91_ADC_LOWRES		(1 << 4)	/* Low Resolution */
47 #define		AT91_ADC_SLEEP		(1 << 5)	/* Sleep Mode */
48 #define		AT91_ADC_PENDET		(1 << 6)	/* Pen contact detection enable */
49 #define		AT91_ADC_PRESCAL_9260	(0x3f << 8)	/* Prescalar Rate Selection */
50 #define		AT91_ADC_PRESCAL_9G45	(0xff << 8)
51 #define			AT91_ADC_PRESCAL_(x)	((x) << 8)
52 #define		AT91_ADC_STARTUP_9260	(0x1f << 16)	/* Startup Up Time */
53 #define		AT91_ADC_STARTUP_9G45	(0x7f << 16)
54 #define		AT91_ADC_STARTUP_9X5	(0xf << 16)
55 #define			AT91_ADC_STARTUP_(x)	((x) << 16)
56 #define		AT91_ADC_SHTIM		(0xf  << 24)	/* Sample & Hold Time */
57 #define			AT91_ADC_SHTIM_(x)	((x) << 24)
58 #define		AT91_ADC_PENDBC		(0x0f << 28)	/* Pen Debounce time */
59 #define			AT91_ADC_PENDBC_(x)	((x) << 28)
60 
61 #define AT91_ADC_TSR		0x0C
62 #define		AT91_ADC_TSR_SHTIM	(0xf  << 24)	/* Sample & Hold Time */
63 #define			AT91_ADC_TSR_SHTIM_(x)	((x) << 24)
64 
65 #define AT91_ADC_CHER		0x10		/* Channel Enable Register */
66 #define AT91_ADC_CHDR		0x14		/* Channel Disable Register */
67 #define AT91_ADC_CHSR		0x18		/* Channel Status Register */
68 #define		AT91_ADC_CH(n)		(1 << (n))	/* Channel Number */
69 
70 #define AT91_ADC_SR		0x1C		/* Status Register */
71 #define		AT91_ADC_EOC(n)		(1 << (n))	/* End of Conversion on Channel N */
72 #define		AT91_ADC_OVRE(n)	(1 << ((n) + 8))/* Overrun Error on Channel N */
73 #define		AT91_ADC_DRDY		(1 << 16)	/* Data Ready */
74 #define		AT91_ADC_GOVRE		(1 << 17)	/* General Overrun Error */
75 #define		AT91_ADC_ENDRX		(1 << 18)	/* End of RX Buffer */
76 #define		AT91_ADC_RXFUFF		(1 << 19)	/* RX Buffer Full */
77 
78 #define AT91_ADC_SR_9X5		0x30		/* Status Register for 9x5 */
79 #define		AT91_ADC_SR_DRDY_9X5	(1 << 24)	/* Data Ready */
80 
81 #define AT91_ADC_LCDR		0x20		/* Last Converted Data Register */
82 #define		AT91_ADC_LDATA		(0x3ff)
83 
84 #define AT91_ADC_IER		0x24		/* Interrupt Enable Register */
85 #define AT91_ADC_IDR		0x28		/* Interrupt Disable Register */
86 #define AT91_ADC_IMR		0x2C		/* Interrupt Mask Register */
87 #define		AT91RL_ADC_IER_PEN	(1 << 20)
88 #define		AT91RL_ADC_IER_NOPEN	(1 << 21)
89 #define		AT91_ADC_IER_PEN	(1 << 29)
90 #define		AT91_ADC_IER_NOPEN	(1 << 30)
91 #define		AT91_ADC_IER_XRDY	(1 << 20)
92 #define		AT91_ADC_IER_YRDY	(1 << 21)
93 #define		AT91_ADC_IER_PRDY	(1 << 22)
94 #define		AT91_ADC_ISR_PENS	(1 << 31)
95 
96 #define AT91_ADC_CHR(n)		(0x30 + ((n) * 4))	/* Channel Data Register N */
97 #define		AT91_ADC_DATA		(0x3ff)
98 
99 #define AT91_ADC_CDR0_9X5	(0x50)			/* Channel Data Register 0 for 9X5 */
100 
101 #define AT91_ADC_ACR		0x94	/* Analog Control Register */
102 #define		AT91_ADC_ACR_PENDETSENS	(0x3 << 0)	/* pull-up resistor */
103 
104 #define AT91_ADC_TSMR		0xB0
105 #define		AT91_ADC_TSMR_TSMODE	(3 << 0)	/* Touch Screen Mode */
106 #define			AT91_ADC_TSMR_TSMODE_NONE		(0 << 0)
107 #define			AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS	(1 << 0)
108 #define			AT91_ADC_TSMR_TSMODE_4WIRE_PRESS	(2 << 0)
109 #define			AT91_ADC_TSMR_TSMODE_5WIRE		(3 << 0)
110 #define		AT91_ADC_TSMR_TSAV	(3 << 4)	/* Averages samples */
111 #define			AT91_ADC_TSMR_TSAV_(x)		((x) << 4)
112 #define		AT91_ADC_TSMR_SCTIM	(0x0f << 16)	/* Switch closure time */
113 #define			AT91_ADC_TSMR_SCTIM_(x)		((x) << 16)
114 #define		AT91_ADC_TSMR_PENDBC	(0x0f << 28)	/* Pen Debounce time */
115 #define			AT91_ADC_TSMR_PENDBC_(x)	((x) << 28)
116 #define		AT91_ADC_TSMR_NOTSDMA	(1 << 22)	/* No Touchscreen DMA */
117 #define		AT91_ADC_TSMR_PENDET_DIS	(0 << 24)	/* Pen contact detection disable */
118 #define		AT91_ADC_TSMR_PENDET_ENA	(1 << 24)	/* Pen contact detection enable */
119 
120 #define AT91_ADC_TSXPOSR	0xB4
121 #define AT91_ADC_TSYPOSR	0xB8
122 #define AT91_ADC_TSPRESSR	0xBC
123 
124 #define AT91_ADC_TRGR_9260	AT91_ADC_MR
125 #define AT91_ADC_TRGR_9G45	0x08
126 #define AT91_ADC_TRGR_9X5	0xC0
127 
128 /* Trigger Register bit field */
129 #define		AT91_ADC_TRGR_TRGPER	(0xffff << 16)
130 #define			AT91_ADC_TRGR_TRGPER_(x)	((x) << 16)
131 #define		AT91_ADC_TRGR_TRGMOD	(0x7 << 0)
132 #define			AT91_ADC_TRGR_NONE		(0 << 0)
133 #define			AT91_ADC_TRGR_MOD_PERIOD_TRIG	(5 << 0)
134 
135 #define AT91_ADC_CHAN(st, ch) \
136 	(st->registers->channel_base + (ch * 4))
137 #define at91_adc_readl(st, reg) \
138 	(readl_relaxed(st->reg_base + reg))
139 #define at91_adc_writel(st, reg, val) \
140 	(writel_relaxed(val, st->reg_base + reg))
141 
142 #define DRIVER_NAME		"at91_adc"
143 #define MAX_POS_BITS		12
144 
145 #define TOUCH_SAMPLE_PERIOD_US		2000	/* 2ms */
146 #define TOUCH_PEN_DETECT_DEBOUNCE_US	200
147 
148 #define MAX_RLPOS_BITS         10
149 #define TOUCH_SAMPLE_PERIOD_US_RL      10000   /* 10ms, the SoC can't keep up with 2ms */
150 #define TOUCH_SHTIM                    0xa
151 #define TOUCH_SCTIM_US		10		/* 10us for the Touchscreen Switches Closure Time */
152 
153 enum atmel_adc_ts_type {
154 	ATMEL_ADC_TOUCHSCREEN_NONE = 0,
155 	ATMEL_ADC_TOUCHSCREEN_4WIRE = 4,
156 	ATMEL_ADC_TOUCHSCREEN_5WIRE = 5,
157 };
158 
159 /**
160  * struct at91_adc_trigger - description of triggers
161  * @name:		name of the trigger advertised to the user
162  * @value:		value to set in the ADC's trigger setup register
163  *			to enable the trigger
164  * @is_external:	Does the trigger rely on an external pin?
165  */
166 struct at91_adc_trigger {
167 	const char	*name;
168 	u8		value;
169 	bool		is_external;
170 };
171 
172 /**
173  * struct at91_adc_reg_desc - Various informations relative to registers
174  * @channel_base:	Base offset for the channel data registers
175  * @drdy_mask:		Mask of the DRDY field in the relevant registers
176  *			(Interruptions registers mostly)
177  * @status_register:	Offset of the Interrupt Status Register
178  * @trigger_register:	Offset of the Trigger setup register
179  * @mr_prescal_mask:	Mask of the PRESCAL field in the adc MR register
180  * @mr_startup_mask:	Mask of the STARTUP field in the adc MR register
181  */
182 struct at91_adc_reg_desc {
183 	u8	channel_base;
184 	u32	drdy_mask;
185 	u8	status_register;
186 	u8	trigger_register;
187 	u32	mr_prescal_mask;
188 	u32	mr_startup_mask;
189 };
190 
191 struct at91_adc_caps {
192 	bool	has_ts;		/* Support touch screen */
193 	bool	has_tsmr;	/* only at91sam9x5, sama5d3 have TSMR reg */
194 	/*
195 	 * Numbers of sampling data will be averaged. Can be 0~3.
196 	 * Hardware can average (2 ^ ts_filter_average) sample data.
197 	 */
198 	u8	ts_filter_average;
199 	/* Pen Detection input pull-up resistor, can be 0~3 */
200 	u8	ts_pen_detect_sensitivity;
201 
202 	/* startup time calculate function */
203 	u32 (*calc_startup_ticks)(u32 startup_time, u32 adc_clk_khz);
204 
205 	u8	num_channels;
206 
207 	u8	low_res_bits;
208 	u8	high_res_bits;
209 	u32	trigger_number;
210 	const struct at91_adc_trigger *triggers;
211 	struct at91_adc_reg_desc registers;
212 };
213 
214 struct at91_adc_state {
215 	struct clk		*adc_clk;
216 	u16			*buffer;
217 	unsigned long		channels_mask;
218 	struct clk		*clk;
219 	bool			done;
220 	int			irq;
221 	u16			last_value;
222 	int			chnb;
223 	struct mutex		lock;
224 	u8			num_channels;
225 	void __iomem		*reg_base;
226 	const struct at91_adc_reg_desc *registers;
227 	u32			startup_time;
228 	u8			sample_hold_time;
229 	bool			sleep_mode;
230 	struct iio_trigger	**trig;
231 	bool			use_external;
232 	u32			vref_mv;
233 	u32			res;		/* resolution used for convertions */
234 	wait_queue_head_t	wq_data_avail;
235 	const struct at91_adc_caps	*caps;
236 
237 	/*
238 	 * Following ADC channels are shared by touchscreen:
239 	 *
240 	 * CH0 -- Touch screen XP/UL
241 	 * CH1 -- Touch screen XM/UR
242 	 * CH2 -- Touch screen YP/LL
243 	 * CH3 -- Touch screen YM/Sense
244 	 * CH4 -- Touch screen LR(5-wire only)
245 	 *
246 	 * The bitfields below represents the reserved channel in the
247 	 * touchscreen mode.
248 	 */
249 #define CHAN_MASK_TOUCHSCREEN_4WIRE	(0xf << 0)
250 #define CHAN_MASK_TOUCHSCREEN_5WIRE	(0x1f << 0)
251 	enum atmel_adc_ts_type	touchscreen_type;
252 	struct input_dev	*ts_input;
253 
254 	u16			ts_sample_period_val;
255 	u32			ts_pressure_threshold;
256 	u16			ts_pendbc;
257 
258 	bool			ts_bufferedmeasure;
259 	u32			ts_prev_absx;
260 	u32			ts_prev_absy;
261 };
262 
263 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
264 {
265 	struct iio_poll_func *pf = p;
266 	struct iio_dev *idev = pf->indio_dev;
267 	struct at91_adc_state *st = iio_priv(idev);
268 	struct iio_chan_spec const *chan;
269 	int i, j = 0;
270 
271 	for (i = 0; i < idev->masklength; i++) {
272 		if (!test_bit(i, idev->active_scan_mask))
273 			continue;
274 		chan = idev->channels + i;
275 		st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, chan->channel));
276 		j++;
277 	}
278 
279 	iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
280 
281 	iio_trigger_notify_done(idev->trig);
282 
283 	/* Needed to ACK the DRDY interruption */
284 	at91_adc_readl(st, AT91_ADC_LCDR);
285 
286 	enable_irq(st->irq);
287 
288 	return IRQ_HANDLED;
289 }
290 
291 /* Handler for classic adc channel eoc trigger */
292 static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
293 {
294 	struct at91_adc_state *st = iio_priv(idev);
295 
296 	if (iio_buffer_enabled(idev)) {
297 		disable_irq_nosync(irq);
298 		iio_trigger_poll(idev->trig);
299 	} else {
300 		st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
301 		/* Needed to ACK the DRDY interruption */
302 		at91_adc_readl(st, AT91_ADC_LCDR);
303 		st->done = true;
304 		wake_up_interruptible(&st->wq_data_avail);
305 	}
306 }
307 
308 static int at91_ts_sample(struct iio_dev *idev)
309 {
310 	struct at91_adc_state *st = iio_priv(idev);
311 	unsigned int xscale, yscale, reg, z1, z2;
312 	unsigned int x, y, pres, xpos, ypos;
313 	unsigned int rxp = 1;
314 	unsigned int factor = 1000;
315 
316 	unsigned int xyz_mask_bits = st->res;
317 	unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
318 
319 	/* calculate position */
320 	/* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
321 	reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
322 	xpos = reg & xyz_mask;
323 	x = (xpos << MAX_POS_BITS) - xpos;
324 	xscale = (reg >> 16) & xyz_mask;
325 	if (xscale == 0) {
326 		dev_err(&idev->dev, "Error: xscale == 0!\n");
327 		return -1;
328 	}
329 	x /= xscale;
330 
331 	/* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
332 	reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
333 	ypos = reg & xyz_mask;
334 	y = (ypos << MAX_POS_BITS) - ypos;
335 	yscale = (reg >> 16) & xyz_mask;
336 	if (yscale == 0) {
337 		dev_err(&idev->dev, "Error: yscale == 0!\n");
338 		return -1;
339 	}
340 	y /= yscale;
341 
342 	/* calculate the pressure */
343 	reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
344 	z1 = reg & xyz_mask;
345 	z2 = (reg >> 16) & xyz_mask;
346 
347 	if (z1 != 0)
348 		pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
349 			/ factor;
350 	else
351 		pres = st->ts_pressure_threshold;	/* no pen contacted */
352 
353 	dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
354 				xpos, xscale, ypos, yscale, z1, z2, pres);
355 
356 	if (pres < st->ts_pressure_threshold) {
357 		dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
358 					x, y, pres / factor);
359 		input_report_abs(st->ts_input, ABS_X, x);
360 		input_report_abs(st->ts_input, ABS_Y, y);
361 		input_report_abs(st->ts_input, ABS_PRESSURE, pres);
362 		input_report_key(st->ts_input, BTN_TOUCH, 1);
363 		input_sync(st->ts_input);
364 	} else {
365 		dev_dbg(&idev->dev, "pressure too low: not reporting\n");
366 	}
367 
368 	return 0;
369 }
370 
371 static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
372 {
373 	struct iio_dev *idev = private;
374 	struct at91_adc_state *st = iio_priv(idev);
375 	u32 status = at91_adc_readl(st, st->registers->status_register);
376 	unsigned int reg;
377 
378 	status &= at91_adc_readl(st, AT91_ADC_IMR);
379 	if (status & GENMASK(st->num_channels - 1, 0))
380 		handle_adc_eoc_trigger(irq, idev);
381 
382 	if (status & AT91RL_ADC_IER_PEN) {
383 		/* Disabling pen debounce is required to get a NOPEN irq */
384 		reg = at91_adc_readl(st, AT91_ADC_MR);
385 		reg &= ~AT91_ADC_PENDBC;
386 		at91_adc_writel(st, AT91_ADC_MR, reg);
387 
388 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
389 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
390 				| AT91_ADC_EOC(3));
391 		/* Set up period trigger for sampling */
392 		at91_adc_writel(st, st->registers->trigger_register,
393 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
394 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
395 	} else if (status & AT91RL_ADC_IER_NOPEN) {
396 		reg = at91_adc_readl(st, AT91_ADC_MR);
397 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
398 		at91_adc_writel(st, AT91_ADC_MR, reg);
399 		at91_adc_writel(st, st->registers->trigger_register,
400 			AT91_ADC_TRGR_NONE);
401 
402 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
403 				| AT91_ADC_EOC(3));
404 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
405 		st->ts_bufferedmeasure = false;
406 		input_report_key(st->ts_input, BTN_TOUCH, 0);
407 		input_sync(st->ts_input);
408 	} else if (status & AT91_ADC_EOC(3) && st->ts_input) {
409 		/* Conversion finished and we've a touchscreen */
410 		if (st->ts_bufferedmeasure) {
411 			/*
412 			 * Last measurement is always discarded, since it can
413 			 * be erroneous.
414 			 * Always report previous measurement
415 			 */
416 			input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
417 			input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
418 			input_report_key(st->ts_input, BTN_TOUCH, 1);
419 			input_sync(st->ts_input);
420 		} else
421 			st->ts_bufferedmeasure = true;
422 
423 		/* Now make new measurement */
424 		st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
425 				   << MAX_RLPOS_BITS;
426 		st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
427 
428 		st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
429 				   << MAX_RLPOS_BITS;
430 		st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
431 	}
432 
433 	return IRQ_HANDLED;
434 }
435 
436 static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
437 {
438 	struct iio_dev *idev = private;
439 	struct at91_adc_state *st = iio_priv(idev);
440 	u32 status = at91_adc_readl(st, st->registers->status_register);
441 	const uint32_t ts_data_irq_mask =
442 		AT91_ADC_IER_XRDY |
443 		AT91_ADC_IER_YRDY |
444 		AT91_ADC_IER_PRDY;
445 
446 	if (status & GENMASK(st->num_channels - 1, 0))
447 		handle_adc_eoc_trigger(irq, idev);
448 
449 	if (status & AT91_ADC_IER_PEN) {
450 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
451 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
452 			ts_data_irq_mask);
453 		/* Set up period trigger for sampling */
454 		at91_adc_writel(st, st->registers->trigger_register,
455 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
456 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
457 	} else if (status & AT91_ADC_IER_NOPEN) {
458 		at91_adc_writel(st, st->registers->trigger_register, 0);
459 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
460 			ts_data_irq_mask);
461 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
462 
463 		input_report_key(st->ts_input, BTN_TOUCH, 0);
464 		input_sync(st->ts_input);
465 	} else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
466 		/* Now all touchscreen data is ready */
467 
468 		if (status & AT91_ADC_ISR_PENS) {
469 			/* validate data by pen contact */
470 			at91_ts_sample(idev);
471 		} else {
472 			/* triggered by event that is no pen contact, just read
473 			 * them to clean the interrupt and discard all.
474 			 */
475 			at91_adc_readl(st, AT91_ADC_TSXPOSR);
476 			at91_adc_readl(st, AT91_ADC_TSYPOSR);
477 			at91_adc_readl(st, AT91_ADC_TSPRESSR);
478 		}
479 	}
480 
481 	return IRQ_HANDLED;
482 }
483 
484 static int at91_adc_channel_init(struct iio_dev *idev)
485 {
486 	struct at91_adc_state *st = iio_priv(idev);
487 	struct iio_chan_spec *chan_array, *timestamp;
488 	int bit, idx = 0;
489 	unsigned long rsvd_mask = 0;
490 
491 	/* If touchscreen is enable, then reserve the adc channels */
492 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
493 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
494 	else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
495 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
496 
497 	/* set up the channel mask to reserve touchscreen channels */
498 	st->channels_mask &= ~rsvd_mask;
499 
500 	idev->num_channels = bitmap_weight(&st->channels_mask,
501 					   st->num_channels) + 1;
502 
503 	chan_array = devm_kzalloc(&idev->dev,
504 				  ((idev->num_channels + 1) *
505 					sizeof(struct iio_chan_spec)),
506 				  GFP_KERNEL);
507 
508 	if (!chan_array)
509 		return -ENOMEM;
510 
511 	for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
512 		struct iio_chan_spec *chan = chan_array + idx;
513 
514 		chan->type = IIO_VOLTAGE;
515 		chan->indexed = 1;
516 		chan->channel = bit;
517 		chan->scan_index = idx;
518 		chan->scan_type.sign = 'u';
519 		chan->scan_type.realbits = st->res;
520 		chan->scan_type.storagebits = 16;
521 		chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
522 		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
523 		idx++;
524 	}
525 	timestamp = chan_array + idx;
526 
527 	timestamp->type = IIO_TIMESTAMP;
528 	timestamp->channel = -1;
529 	timestamp->scan_index = idx;
530 	timestamp->scan_type.sign = 's';
531 	timestamp->scan_type.realbits = 64;
532 	timestamp->scan_type.storagebits = 64;
533 
534 	idev->channels = chan_array;
535 	return idev->num_channels;
536 }
537 
538 static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
539 					     const struct at91_adc_trigger *triggers,
540 					     const char *trigger_name)
541 {
542 	struct at91_adc_state *st = iio_priv(idev);
543 	int i;
544 
545 	for (i = 0; i < st->caps->trigger_number; i++) {
546 		char *name = kasprintf(GFP_KERNEL,
547 				"%s-dev%d-%s",
548 				idev->name,
549 				iio_device_id(idev),
550 				triggers[i].name);
551 		if (!name)
552 			return -ENOMEM;
553 
554 		if (strcmp(trigger_name, name) == 0) {
555 			kfree(name);
556 			if (triggers[i].value == 0)
557 				return -EINVAL;
558 			return triggers[i].value;
559 		}
560 
561 		kfree(name);
562 	}
563 
564 	return -EINVAL;
565 }
566 
567 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
568 {
569 	struct iio_dev *idev = iio_trigger_get_drvdata(trig);
570 	struct at91_adc_state *st = iio_priv(idev);
571 	const struct at91_adc_reg_desc *reg = st->registers;
572 	u32 status = at91_adc_readl(st, reg->trigger_register);
573 	int value;
574 	u8 bit;
575 
576 	value = at91_adc_get_trigger_value_by_name(idev,
577 						   st->caps->triggers,
578 						   idev->trig->name);
579 	if (value < 0)
580 		return value;
581 
582 	if (state) {
583 		st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
584 		if (st->buffer == NULL)
585 			return -ENOMEM;
586 
587 		at91_adc_writel(st, reg->trigger_register,
588 				status | value);
589 
590 		for_each_set_bit(bit, idev->active_scan_mask,
591 				 st->num_channels) {
592 			struct iio_chan_spec const *chan = idev->channels + bit;
593 			at91_adc_writel(st, AT91_ADC_CHER,
594 					AT91_ADC_CH(chan->channel));
595 		}
596 
597 		at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
598 
599 	} else {
600 		at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
601 
602 		at91_adc_writel(st, reg->trigger_register,
603 				status & ~value);
604 
605 		for_each_set_bit(bit, idev->active_scan_mask,
606 				 st->num_channels) {
607 			struct iio_chan_spec const *chan = idev->channels + bit;
608 			at91_adc_writel(st, AT91_ADC_CHDR,
609 					AT91_ADC_CH(chan->channel));
610 		}
611 		kfree(st->buffer);
612 	}
613 
614 	return 0;
615 }
616 
617 static const struct iio_trigger_ops at91_adc_trigger_ops = {
618 	.set_trigger_state = &at91_adc_configure_trigger,
619 };
620 
621 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
622 						     const struct at91_adc_trigger *trigger)
623 {
624 	struct iio_trigger *trig;
625 	int ret;
626 
627 	trig = iio_trigger_alloc(idev->dev.parent, "%s-dev%d-%s", idev->name,
628 				 iio_device_id(idev), trigger->name);
629 	if (trig == NULL)
630 		return NULL;
631 
632 	iio_trigger_set_drvdata(trig, idev);
633 	trig->ops = &at91_adc_trigger_ops;
634 
635 	ret = iio_trigger_register(trig);
636 	if (ret) {
637 		iio_trigger_free(trig);
638 		return NULL;
639 	}
640 
641 	return trig;
642 }
643 
644 static int at91_adc_trigger_init(struct iio_dev *idev)
645 {
646 	struct at91_adc_state *st = iio_priv(idev);
647 	int i, ret;
648 
649 	st->trig = devm_kcalloc(&idev->dev,
650 				st->caps->trigger_number, sizeof(*st->trig),
651 				GFP_KERNEL);
652 
653 	if (st->trig == NULL) {
654 		ret = -ENOMEM;
655 		goto error_ret;
656 	}
657 
658 	for (i = 0; i < st->caps->trigger_number; i++) {
659 		if (st->caps->triggers[i].is_external && !(st->use_external))
660 			continue;
661 
662 		st->trig[i] = at91_adc_allocate_trigger(idev,
663 							st->caps->triggers + i);
664 		if (st->trig[i] == NULL) {
665 			dev_err(&idev->dev,
666 				"Could not allocate trigger %d\n", i);
667 			ret = -ENOMEM;
668 			goto error_trigger;
669 		}
670 	}
671 
672 	return 0;
673 
674 error_trigger:
675 	for (i--; i >= 0; i--) {
676 		iio_trigger_unregister(st->trig[i]);
677 		iio_trigger_free(st->trig[i]);
678 	}
679 error_ret:
680 	return ret;
681 }
682 
683 static void at91_adc_trigger_remove(struct iio_dev *idev)
684 {
685 	struct at91_adc_state *st = iio_priv(idev);
686 	int i;
687 
688 	for (i = 0; i < st->caps->trigger_number; i++) {
689 		iio_trigger_unregister(st->trig[i]);
690 		iio_trigger_free(st->trig[i]);
691 	}
692 }
693 
694 static int at91_adc_buffer_init(struct iio_dev *idev)
695 {
696 	return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
697 		&at91_adc_trigger_handler, NULL);
698 }
699 
700 static void at91_adc_buffer_remove(struct iio_dev *idev)
701 {
702 	iio_triggered_buffer_cleanup(idev);
703 }
704 
705 static int at91_adc_read_raw(struct iio_dev *idev,
706 			     struct iio_chan_spec const *chan,
707 			     int *val, int *val2, long mask)
708 {
709 	struct at91_adc_state *st = iio_priv(idev);
710 	int ret;
711 
712 	switch (mask) {
713 	case IIO_CHAN_INFO_RAW:
714 		mutex_lock(&st->lock);
715 
716 		st->chnb = chan->channel;
717 		at91_adc_writel(st, AT91_ADC_CHER,
718 				AT91_ADC_CH(chan->channel));
719 		at91_adc_writel(st, AT91_ADC_IER, BIT(chan->channel));
720 		at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
721 
722 		ret = wait_event_interruptible_timeout(st->wq_data_avail,
723 						       st->done,
724 						       msecs_to_jiffies(1000));
725 
726 		/* Disable interrupts, regardless if adc conversion was
727 		 * successful or not
728 		 */
729 		at91_adc_writel(st, AT91_ADC_CHDR,
730 				AT91_ADC_CH(chan->channel));
731 		at91_adc_writel(st, AT91_ADC_IDR, BIT(chan->channel));
732 
733 		if (ret > 0) {
734 			/* a valid conversion took place */
735 			*val = st->last_value;
736 			st->last_value = 0;
737 			st->done = false;
738 			ret = IIO_VAL_INT;
739 		} else if (ret == 0) {
740 			/* conversion timeout */
741 			dev_err(&idev->dev, "ADC Channel %d timeout.\n",
742 				chan->channel);
743 			ret = -ETIMEDOUT;
744 		}
745 
746 		mutex_unlock(&st->lock);
747 		return ret;
748 
749 	case IIO_CHAN_INFO_SCALE:
750 		*val = st->vref_mv;
751 		*val2 = chan->scan_type.realbits;
752 		return IIO_VAL_FRACTIONAL_LOG2;
753 	default:
754 		break;
755 	}
756 	return -EINVAL;
757 }
758 
759 
760 static u32 calc_startup_ticks_9260(u32 startup_time, u32 adc_clk_khz)
761 {
762 	/*
763 	 * Number of ticks needed to cover the startup time of the ADC
764 	 * as defined in the electrical characteristics of the board,
765 	 * divided by 8. The formula thus is :
766 	 *   Startup Time = (ticks + 1) * 8 / ADC Clock
767 	 */
768 	return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
769 }
770 
771 static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz)
772 {
773 	/*
774 	 * For sama5d3x and at91sam9x5, the formula changes to:
775 	 * Startup Time = <lookup_table_value> / ADC Clock
776 	 */
777 	static const int startup_lookup[] = {
778 		0,   8,   16,  24,
779 		64,  80,  96,  112,
780 		512, 576, 640, 704,
781 		768, 832, 896, 960
782 		};
783 	int i, size = ARRAY_SIZE(startup_lookup);
784 	unsigned int ticks;
785 
786 	ticks = startup_time * adc_clk_khz / 1000;
787 	for (i = 0; i < size; i++)
788 		if (ticks < startup_lookup[i])
789 			break;
790 
791 	ticks = i;
792 	if (ticks == size)
793 		/* Reach the end of lookup table */
794 		ticks = size - 1;
795 
796 	return ticks;
797 }
798 
799 static int at91_adc_probe_dt_ts(struct device_node *node,
800 	struct at91_adc_state *st, struct device *dev)
801 {
802 	int ret;
803 	u32 prop;
804 
805 	ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
806 	if (ret) {
807 		dev_info(dev, "ADC Touch screen is disabled.\n");
808 		return 0;
809 	}
810 
811 	switch (prop) {
812 	case 4:
813 	case 5:
814 		st->touchscreen_type = prop;
815 		break;
816 	default:
817 		dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
818 		return -EINVAL;
819 	}
820 
821 	if (!st->caps->has_tsmr)
822 		return 0;
823 	prop = 0;
824 	of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
825 	st->ts_pressure_threshold = prop;
826 	if (st->ts_pressure_threshold) {
827 		return 0;
828 	} else {
829 		dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
830 		return -EINVAL;
831 	}
832 }
833 
834 static const struct iio_info at91_adc_info = {
835 	.read_raw = &at91_adc_read_raw,
836 };
837 
838 /* Touchscreen related functions */
839 static int atmel_ts_open(struct input_dev *dev)
840 {
841 	struct at91_adc_state *st = input_get_drvdata(dev);
842 
843 	if (st->caps->has_tsmr)
844 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
845 	else
846 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
847 	return 0;
848 }
849 
850 static void atmel_ts_close(struct input_dev *dev)
851 {
852 	struct at91_adc_state *st = input_get_drvdata(dev);
853 
854 	if (st->caps->has_tsmr)
855 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
856 	else
857 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
858 }
859 
860 static int at91_ts_hw_init(struct iio_dev *idev, u32 adc_clk_khz)
861 {
862 	struct at91_adc_state *st = iio_priv(idev);
863 	u32 reg = 0;
864 	u32 tssctim = 0;
865 	int i = 0;
866 
867 	/* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
868 	 * pen detect noise.
869 	 * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
870 	 */
871 	st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
872 				 1000, 1);
873 
874 	while (st->ts_pendbc >> ++i)
875 		;	/* Empty! Find the shift offset */
876 	if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
877 		st->ts_pendbc = i;
878 	else
879 		st->ts_pendbc = i - 1;
880 
881 	if (!st->caps->has_tsmr) {
882 		reg = at91_adc_readl(st, AT91_ADC_MR);
883 		reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
884 
885 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
886 		at91_adc_writel(st, AT91_ADC_MR, reg);
887 
888 		reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
889 		at91_adc_writel(st, AT91_ADC_TSR, reg);
890 
891 		st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
892 						    adc_clk_khz / 1000) - 1, 1);
893 
894 		return 0;
895 	}
896 
897 	/* Touchscreen Switches Closure time needed for allowing the value to
898 	 * stabilize.
899 	 * Switch Closure Time = (TSSCTIM * 4) ADCClock periods
900 	 */
901 	tssctim = DIV_ROUND_UP(TOUCH_SCTIM_US * adc_clk_khz / 1000, 4);
902 	dev_dbg(&idev->dev, "adc_clk at: %d KHz, tssctim at: %d\n",
903 		adc_clk_khz, tssctim);
904 
905 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
906 		reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
907 	else
908 		reg = AT91_ADC_TSMR_TSMODE_5WIRE;
909 
910 	reg |= AT91_ADC_TSMR_SCTIM_(tssctim) & AT91_ADC_TSMR_SCTIM;
911 	reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
912 	       & AT91_ADC_TSMR_TSAV;
913 	reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
914 	reg |= AT91_ADC_TSMR_NOTSDMA;
915 	reg |= AT91_ADC_TSMR_PENDET_ENA;
916 	reg |= 0x03 << 8;	/* TSFREQ, needs to be bigger than TSAV */
917 
918 	at91_adc_writel(st, AT91_ADC_TSMR, reg);
919 
920 	/* Change adc internal resistor value for better pen detection,
921 	 * default value is 100 kOhm.
922 	 * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
923 	 * option only available on ES2 and higher
924 	 */
925 	at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
926 			& AT91_ADC_ACR_PENDETSENS);
927 
928 	/* Sample Period Time = (TRGPER + 1) / ADCClock */
929 	st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
930 			adc_clk_khz / 1000) - 1, 1);
931 
932 	return 0;
933 }
934 
935 static int at91_ts_register(struct iio_dev *idev,
936 		struct platform_device *pdev)
937 {
938 	struct at91_adc_state *st = iio_priv(idev);
939 	struct input_dev *input;
940 	int ret;
941 
942 	input = input_allocate_device();
943 	if (!input) {
944 		dev_err(&idev->dev, "Failed to allocate TS device!\n");
945 		return -ENOMEM;
946 	}
947 
948 	input->name = DRIVER_NAME;
949 	input->id.bustype = BUS_HOST;
950 	input->dev.parent = &pdev->dev;
951 	input->open = atmel_ts_open;
952 	input->close = atmel_ts_close;
953 
954 	__set_bit(EV_ABS, input->evbit);
955 	__set_bit(EV_KEY, input->evbit);
956 	__set_bit(BTN_TOUCH, input->keybit);
957 	if (st->caps->has_tsmr) {
958 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
959 				     0, 0);
960 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
961 				     0, 0);
962 		input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
963 	} else {
964 		if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
965 			dev_err(&pdev->dev,
966 				"This touchscreen controller only support 4 wires\n");
967 			ret = -EINVAL;
968 			goto err;
969 		}
970 
971 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
972 				     0, 0);
973 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
974 				     0, 0);
975 	}
976 
977 	st->ts_input = input;
978 	input_set_drvdata(input, st);
979 
980 	ret = input_register_device(input);
981 	if (ret)
982 		goto err;
983 
984 	return ret;
985 
986 err:
987 	input_free_device(st->ts_input);
988 	return ret;
989 }
990 
991 static void at91_ts_unregister(struct at91_adc_state *st)
992 {
993 	input_unregister_device(st->ts_input);
994 }
995 
996 static int at91_adc_probe(struct platform_device *pdev)
997 {
998 	unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
999 	struct device_node *node = pdev->dev.of_node;
1000 	int ret;
1001 	struct iio_dev *idev;
1002 	struct at91_adc_state *st;
1003 	u32 reg, prop;
1004 	char *s;
1005 
1006 	idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
1007 	if (!idev)
1008 		return -ENOMEM;
1009 
1010 	st = iio_priv(idev);
1011 
1012 	st->caps = of_device_get_match_data(&pdev->dev);
1013 
1014 	st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
1015 
1016 	if (of_property_read_u32(node, "atmel,adc-channels-used", &prop))
1017 		return dev_err_probe(&idev->dev, -EINVAL,
1018 				     "Missing adc-channels-used property in the DT.\n");
1019 	st->channels_mask = prop;
1020 
1021 	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
1022 
1023 	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop))
1024 		return dev_err_probe(&idev->dev, -EINVAL,
1025 				     "Missing adc-startup-time property in the DT.\n");
1026 	st->startup_time = prop;
1027 
1028 	prop = 0;
1029 	of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
1030 	st->sample_hold_time = prop;
1031 
1032 	if (of_property_read_u32(node, "atmel,adc-vref", &prop))
1033 		return dev_err_probe(&idev->dev, -EINVAL,
1034 				     "Missing adc-vref property in the DT.\n");
1035 	st->vref_mv = prop;
1036 
1037 	st->res = st->caps->high_res_bits;
1038 	if (st->caps->low_res_bits &&
1039 	    !of_property_read_string(node, "atmel,adc-use-res", (const char **)&s)
1040 	    && !strcmp(s, "lowres"))
1041 		st->res = st->caps->low_res_bits;
1042 
1043 	dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
1044 
1045 	st->registers = &st->caps->registers;
1046 	st->num_channels = st->caps->num_channels;
1047 
1048 	/* Check if touchscreen is supported. */
1049 	if (st->caps->has_ts) {
1050 		ret = at91_adc_probe_dt_ts(node, st, &idev->dev);
1051 		if (ret)
1052 			return ret;
1053 	}
1054 
1055 	platform_set_drvdata(pdev, idev);
1056 
1057 	idev->name = dev_name(&pdev->dev);
1058 	idev->modes = INDIO_DIRECT_MODE;
1059 	idev->info = &at91_adc_info;
1060 
1061 	st->irq = platform_get_irq(pdev, 0);
1062 	if (st->irq < 0)
1063 		return -ENODEV;
1064 
1065 	st->reg_base = devm_platform_ioremap_resource(pdev, 0);
1066 	if (IS_ERR(st->reg_base))
1067 		return PTR_ERR(st->reg_base);
1068 
1069 	/*
1070 	 * Disable all IRQs before setting up the handler
1071 	 */
1072 	at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
1073 	at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
1074 
1075 	if (st->caps->has_tsmr)
1076 		ret = devm_request_irq(&pdev->dev, st->irq,
1077 				       at91_adc_9x5_interrupt, 0,
1078 				       pdev->dev.driver->name, idev);
1079 	else
1080 		ret = devm_request_irq(&pdev->dev, st->irq,
1081 				       at91_adc_rl_interrupt, 0,
1082 				       pdev->dev.driver->name, idev);
1083 	if (ret)
1084 		return dev_err_probe(&pdev->dev, ret,
1085 				     "Failed to allocate IRQ.\n");
1086 
1087 	st->clk = devm_clk_get_enabled(&pdev->dev, "adc_clk");
1088 	if (IS_ERR(st->clk))
1089 		return dev_err_probe(&pdev->dev, PTR_ERR(st->clk),
1090 				     "Could not prepare or enable the clock.\n");
1091 
1092 	st->adc_clk = devm_clk_get_enabled(&pdev->dev, "adc_op_clk");
1093 	if (IS_ERR(st->adc_clk))
1094 		return dev_err_probe(&pdev->dev, PTR_ERR(st->adc_clk),
1095 				     "Could not prepare or enable the ADC clock.\n");
1096 
1097 	/*
1098 	 * Prescaler rate computation using the formula from the Atmel's
1099 	 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
1100 	 * specified by the electrical characteristics of the board.
1101 	 */
1102 	mstrclk = clk_get_rate(st->clk);
1103 	adc_clk = clk_get_rate(st->adc_clk);
1104 	adc_clk_khz = adc_clk / 1000;
1105 
1106 	dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
1107 		mstrclk, adc_clk);
1108 
1109 	prsc = (mstrclk / (2 * adc_clk)) - 1;
1110 
1111 	if (!st->startup_time)
1112 		return dev_err_probe(&pdev->dev, -EINVAL,
1113 				     "No startup time available.\n");
1114 	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
1115 
1116 	/*
1117 	 * a minimal Sample and Hold Time is necessary for the ADC to guarantee
1118 	 * the best converted final value between two channels selection
1119 	 * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
1120 	 */
1121 	if (st->sample_hold_time > 0)
1122 		shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000)
1123 				 - 1, 1);
1124 	else
1125 		shtim = 0;
1126 
1127 	reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
1128 	reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
1129 	if (st->res == st->caps->low_res_bits)
1130 		reg |= AT91_ADC_LOWRES;
1131 	if (st->sleep_mode)
1132 		reg |= AT91_ADC_SLEEP;
1133 	reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
1134 	at91_adc_writel(st, AT91_ADC_MR, reg);
1135 
1136 	/* Setup the ADC channels available on the board */
1137 	ret = at91_adc_channel_init(idev);
1138 	if (ret < 0)
1139 		return dev_err_probe(&pdev->dev, ret,
1140 				     "Couldn't initialize the channels.\n");
1141 
1142 	init_waitqueue_head(&st->wq_data_avail);
1143 	mutex_init(&st->lock);
1144 
1145 	/*
1146 	 * Since touch screen will set trigger register as period trigger. So
1147 	 * when touch screen is enabled, then we have to disable hardware
1148 	 * trigger for classic adc.
1149 	 */
1150 	if (!st->touchscreen_type) {
1151 		ret = at91_adc_buffer_init(idev);
1152 		if (ret < 0)
1153 			return dev_err_probe(&pdev->dev, ret,
1154 					     "Couldn't initialize the buffer.\n");
1155 
1156 		ret = at91_adc_trigger_init(idev);
1157 		if (ret < 0) {
1158 			dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
1159 			at91_adc_buffer_remove(idev);
1160 			return ret;
1161 		}
1162 	} else {
1163 		ret = at91_ts_register(idev, pdev);
1164 		if (ret)
1165 			return ret;
1166 
1167 		at91_ts_hw_init(idev, adc_clk_khz);
1168 	}
1169 
1170 	ret = iio_device_register(idev);
1171 	if (ret < 0) {
1172 		dev_err(&pdev->dev, "Couldn't register the device.\n");
1173 		goto error_iio_device_register;
1174 	}
1175 
1176 	return 0;
1177 
1178 error_iio_device_register:
1179 	if (!st->touchscreen_type) {
1180 		at91_adc_trigger_remove(idev);
1181 		at91_adc_buffer_remove(idev);
1182 	} else {
1183 		at91_ts_unregister(st);
1184 	}
1185 	return ret;
1186 }
1187 
1188 static void at91_adc_remove(struct platform_device *pdev)
1189 {
1190 	struct iio_dev *idev = platform_get_drvdata(pdev);
1191 	struct at91_adc_state *st = iio_priv(idev);
1192 
1193 	iio_device_unregister(idev);
1194 	if (!st->touchscreen_type) {
1195 		at91_adc_trigger_remove(idev);
1196 		at91_adc_buffer_remove(idev);
1197 	} else {
1198 		at91_ts_unregister(st);
1199 	}
1200 }
1201 
1202 static int at91_adc_suspend(struct device *dev)
1203 {
1204 	struct iio_dev *idev = dev_get_drvdata(dev);
1205 	struct at91_adc_state *st = iio_priv(idev);
1206 
1207 	pinctrl_pm_select_sleep_state(dev);
1208 	clk_disable_unprepare(st->clk);
1209 
1210 	return 0;
1211 }
1212 
1213 static int at91_adc_resume(struct device *dev)
1214 {
1215 	struct iio_dev *idev = dev_get_drvdata(dev);
1216 	struct at91_adc_state *st = iio_priv(idev);
1217 
1218 	clk_prepare_enable(st->clk);
1219 	pinctrl_pm_select_default_state(dev);
1220 
1221 	return 0;
1222 }
1223 
1224 static DEFINE_SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend,
1225 				at91_adc_resume);
1226 
1227 static const struct at91_adc_trigger at91sam9260_triggers[] = {
1228 	{ .name = "timer-counter-0", .value = 0x1 },
1229 	{ .name = "timer-counter-1", .value = 0x3 },
1230 	{ .name = "timer-counter-2", .value = 0x5 },
1231 	{ .name = "external", .value = 0xd, .is_external = true },
1232 };
1233 
1234 static struct at91_adc_caps at91sam9260_caps = {
1235 	.calc_startup_ticks = calc_startup_ticks_9260,
1236 	.num_channels = 4,
1237 	.low_res_bits = 8,
1238 	.high_res_bits = 10,
1239 	.registers = {
1240 		.channel_base = AT91_ADC_CHR(0),
1241 		.drdy_mask = AT91_ADC_DRDY,
1242 		.status_register = AT91_ADC_SR,
1243 		.trigger_register = AT91_ADC_TRGR_9260,
1244 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1245 		.mr_startup_mask = AT91_ADC_STARTUP_9260,
1246 	},
1247 	.triggers = at91sam9260_triggers,
1248 	.trigger_number = ARRAY_SIZE(at91sam9260_triggers),
1249 };
1250 
1251 static const struct at91_adc_trigger at91sam9x5_triggers[] = {
1252 	{ .name = "external-rising", .value = 0x1, .is_external = true },
1253 	{ .name = "external-falling", .value = 0x2, .is_external = true },
1254 	{ .name = "external-any", .value = 0x3, .is_external = true },
1255 	{ .name = "continuous", .value = 0x6 },
1256 };
1257 
1258 static struct at91_adc_caps at91sam9rl_caps = {
1259 	.has_ts = true,
1260 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1261 	.num_channels = 6,
1262 	.low_res_bits = 8,
1263 	.high_res_bits = 10,
1264 	.registers = {
1265 		.channel_base = AT91_ADC_CHR(0),
1266 		.drdy_mask = AT91_ADC_DRDY,
1267 		.status_register = AT91_ADC_SR,
1268 		.trigger_register = AT91_ADC_TRGR_9G45,
1269 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1270 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1271 	},
1272 	.triggers = at91sam9x5_triggers,
1273 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1274 };
1275 
1276 static struct at91_adc_caps at91sam9g45_caps = {
1277 	.has_ts = true,
1278 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1279 	.num_channels = 8,
1280 	.low_res_bits = 8,
1281 	.high_res_bits = 10,
1282 	.registers = {
1283 		.channel_base = AT91_ADC_CHR(0),
1284 		.drdy_mask = AT91_ADC_DRDY,
1285 		.status_register = AT91_ADC_SR,
1286 		.trigger_register = AT91_ADC_TRGR_9G45,
1287 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1288 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1289 	},
1290 	.triggers = at91sam9x5_triggers,
1291 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1292 };
1293 
1294 static struct at91_adc_caps at91sam9x5_caps = {
1295 	.has_ts = true,
1296 	.has_tsmr = true,
1297 	.ts_filter_average = 3,
1298 	.ts_pen_detect_sensitivity = 2,
1299 	.calc_startup_ticks = calc_startup_ticks_9x5,
1300 	.num_channels = 12,
1301 	.low_res_bits = 8,
1302 	.high_res_bits = 10,
1303 	.registers = {
1304 		.channel_base = AT91_ADC_CDR0_9X5,
1305 		.drdy_mask = AT91_ADC_SR_DRDY_9X5,
1306 		.status_register = AT91_ADC_SR_9X5,
1307 		.trigger_register = AT91_ADC_TRGR_9X5,
1308 		/* prescal mask is same as 9G45 */
1309 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1310 		.mr_startup_mask = AT91_ADC_STARTUP_9X5,
1311 	},
1312 	.triggers = at91sam9x5_triggers,
1313 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1314 };
1315 
1316 static struct at91_adc_caps sama5d3_caps = {
1317 	.has_ts = true,
1318 	.has_tsmr = true,
1319 	.ts_filter_average = 3,
1320 	.ts_pen_detect_sensitivity = 2,
1321 	.calc_startup_ticks = calc_startup_ticks_9x5,
1322 	.num_channels = 12,
1323 	.low_res_bits = 0,
1324 	.high_res_bits = 12,
1325 	.registers = {
1326 		.channel_base = AT91_ADC_CDR0_9X5,
1327 		.drdy_mask = AT91_ADC_SR_DRDY_9X5,
1328 		.status_register = AT91_ADC_SR_9X5,
1329 		.trigger_register = AT91_ADC_TRGR_9X5,
1330 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1331 		.mr_startup_mask = AT91_ADC_STARTUP_9X5,
1332 	},
1333 	.triggers = at91sam9x5_triggers,
1334 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1335 };
1336 
1337 static const struct of_device_id at91_adc_dt_ids[] = {
1338 	{ .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
1339 	{ .compatible = "atmel,at91sam9rl-adc", .data = &at91sam9rl_caps },
1340 	{ .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
1341 	{ .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
1342 	{ .compatible = "atmel,sama5d3-adc", .data = &sama5d3_caps },
1343 	{},
1344 };
1345 MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
1346 
1347 static struct platform_driver at91_adc_driver = {
1348 	.probe = at91_adc_probe,
1349 	.remove_new = at91_adc_remove,
1350 	.driver = {
1351 		   .name = DRIVER_NAME,
1352 		   .of_match_table = at91_adc_dt_ids,
1353 		   .pm = pm_sleep_ptr(&at91_adc_pm_ops),
1354 	},
1355 };
1356 
1357 module_platform_driver(at91_adc_driver);
1358 
1359 MODULE_LICENSE("GPL");
1360 MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
1361 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1362