xref: /openbmc/linux/drivers/iio/adc/at91_adc.c (revision 4aea96f4)
1 /*
2  * Driver for the ADC present in the Atmel AT91 evaluation boards.
3  *
4  * Copyright 2011 Free Electrons
5  *
6  * Licensed under the GPLv2 or later.
7  */
8 
9 #include <linux/bitmap.h>
10 #include <linux/bitops.h>
11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
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/of_device.h>
21 #include <linux/platform_device.h>
22 #include <linux/sched.h>
23 #include <linux/slab.h>
24 #include <linux/wait.h>
25 
26 #include <linux/platform_data/at91_adc.h>
27 
28 #include <linux/iio/iio.h>
29 #include <linux/iio/buffer.h>
30 #include <linux/iio/trigger.h>
31 #include <linux/iio/trigger_consumer.h>
32 #include <linux/iio/triggered_buffer.h>
33 #include <linux/pinctrl/consumer.h>
34 
35 /* Registers */
36 #define AT91_ADC_CR		0x00		/* Control Register */
37 #define		AT91_ADC_SWRST		(1 << 0)	/* Software Reset */
38 #define		AT91_ADC_START		(1 << 1)	/* Start Conversion */
39 
40 #define AT91_ADC_MR		0x04		/* Mode Register */
41 #define		AT91_ADC_TSAMOD		(3 << 0)	/* ADC mode */
42 #define		AT91_ADC_TSAMOD_ADC_ONLY_MODE		(0 << 0)	/* ADC Mode */
43 #define		AT91_ADC_TSAMOD_TS_ONLY_MODE		(1 << 0)	/* Touch Screen Only Mode */
44 #define		AT91_ADC_TRGEN		(1 << 0)	/* Trigger Enable */
45 #define		AT91_ADC_TRGSEL		(7 << 1)	/* Trigger Selection */
46 #define			AT91_ADC_TRGSEL_TC0		(0 << 1)
47 #define			AT91_ADC_TRGSEL_TC1		(1 << 1)
48 #define			AT91_ADC_TRGSEL_TC2		(2 << 1)
49 #define			AT91_ADC_TRGSEL_EXTERNAL	(6 << 1)
50 #define		AT91_ADC_LOWRES		(1 << 4)	/* Low Resolution */
51 #define		AT91_ADC_SLEEP		(1 << 5)	/* Sleep Mode */
52 #define		AT91_ADC_PENDET		(1 << 6)	/* Pen contact detection enable */
53 #define		AT91_ADC_PRESCAL_9260	(0x3f << 8)	/* Prescalar Rate Selection */
54 #define		AT91_ADC_PRESCAL_9G45	(0xff << 8)
55 #define			AT91_ADC_PRESCAL_(x)	((x) << 8)
56 #define		AT91_ADC_STARTUP_9260	(0x1f << 16)	/* Startup Up Time */
57 #define		AT91_ADC_STARTUP_9G45	(0x7f << 16)
58 #define		AT91_ADC_STARTUP_9X5	(0xf << 16)
59 #define			AT91_ADC_STARTUP_(x)	((x) << 16)
60 #define		AT91_ADC_SHTIM		(0xf  << 24)	/* Sample & Hold Time */
61 #define			AT91_ADC_SHTIM_(x)	((x) << 24)
62 #define		AT91_ADC_PENDBC		(0x0f << 28)	/* Pen Debounce time */
63 #define			AT91_ADC_PENDBC_(x)	((x) << 28)
64 
65 #define AT91_ADC_TSR		0x0C
66 #define		AT91_ADC_TSR_SHTIM	(0xf  << 24)	/* Sample & Hold Time */
67 #define			AT91_ADC_TSR_SHTIM_(x)	((x) << 24)
68 
69 #define AT91_ADC_CHER		0x10		/* Channel Enable Register */
70 #define AT91_ADC_CHDR		0x14		/* Channel Disable Register */
71 #define AT91_ADC_CHSR		0x18		/* Channel Status Register */
72 #define		AT91_ADC_CH(n)		(1 << (n))	/* Channel Number */
73 
74 #define AT91_ADC_SR		0x1C		/* Status Register */
75 #define		AT91_ADC_EOC(n)		(1 << (n))	/* End of Conversion on Channel N */
76 #define		AT91_ADC_OVRE(n)	(1 << ((n) + 8))/* Overrun Error on Channel N */
77 #define		AT91_ADC_DRDY		(1 << 16)	/* Data Ready */
78 #define		AT91_ADC_GOVRE		(1 << 17)	/* General Overrun Error */
79 #define		AT91_ADC_ENDRX		(1 << 18)	/* End of RX Buffer */
80 #define		AT91_ADC_RXFUFF		(1 << 19)	/* RX Buffer Full */
81 
82 #define AT91_ADC_SR_9X5		0x30		/* Status Register for 9x5 */
83 #define		AT91_ADC_SR_DRDY_9X5	(1 << 24)	/* Data Ready */
84 
85 #define AT91_ADC_LCDR		0x20		/* Last Converted Data Register */
86 #define		AT91_ADC_LDATA		(0x3ff)
87 
88 #define AT91_ADC_IER		0x24		/* Interrupt Enable Register */
89 #define AT91_ADC_IDR		0x28		/* Interrupt Disable Register */
90 #define AT91_ADC_IMR		0x2C		/* Interrupt Mask Register */
91 #define		AT91RL_ADC_IER_PEN	(1 << 20)
92 #define		AT91RL_ADC_IER_NOPEN	(1 << 21)
93 #define		AT91_ADC_IER_PEN	(1 << 29)
94 #define		AT91_ADC_IER_NOPEN	(1 << 30)
95 #define		AT91_ADC_IER_XRDY	(1 << 20)
96 #define		AT91_ADC_IER_YRDY	(1 << 21)
97 #define		AT91_ADC_IER_PRDY	(1 << 22)
98 #define		AT91_ADC_ISR_PENS	(1 << 31)
99 
100 #define AT91_ADC_CHR(n)		(0x30 + ((n) * 4))	/* Channel Data Register N */
101 #define		AT91_ADC_DATA		(0x3ff)
102 
103 #define AT91_ADC_CDR0_9X5	(0x50)			/* Channel Data Register 0 for 9X5 */
104 
105 #define AT91_ADC_ACR		0x94	/* Analog Control Register */
106 #define		AT91_ADC_ACR_PENDETSENS	(0x3 << 0)	/* pull-up resistor */
107 
108 #define AT91_ADC_TSMR		0xB0
109 #define		AT91_ADC_TSMR_TSMODE	(3 << 0)	/* Touch Screen Mode */
110 #define			AT91_ADC_TSMR_TSMODE_NONE		(0 << 0)
111 #define			AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS	(1 << 0)
112 #define			AT91_ADC_TSMR_TSMODE_4WIRE_PRESS	(2 << 0)
113 #define			AT91_ADC_TSMR_TSMODE_5WIRE		(3 << 0)
114 #define		AT91_ADC_TSMR_TSAV	(3 << 4)	/* Averages samples */
115 #define			AT91_ADC_TSMR_TSAV_(x)		((x) << 4)
116 #define		AT91_ADC_TSMR_SCTIM	(0x0f << 16)	/* Switch closure time */
117 #define			AT91_ADC_TSMR_SCTIM_(x)		((x) << 16)
118 #define		AT91_ADC_TSMR_PENDBC	(0x0f << 28)	/* Pen Debounce time */
119 #define			AT91_ADC_TSMR_PENDBC_(x)	((x) << 28)
120 #define		AT91_ADC_TSMR_NOTSDMA	(1 << 22)	/* No Touchscreen DMA */
121 #define		AT91_ADC_TSMR_PENDET_DIS	(0 << 24)	/* Pen contact detection disable */
122 #define		AT91_ADC_TSMR_PENDET_ENA	(1 << 24)	/* Pen contact detection enable */
123 
124 #define AT91_ADC_TSXPOSR	0xB4
125 #define AT91_ADC_TSYPOSR	0xB8
126 #define AT91_ADC_TSPRESSR	0xBC
127 
128 #define AT91_ADC_TRGR_9260	AT91_ADC_MR
129 #define AT91_ADC_TRGR_9G45	0x08
130 #define AT91_ADC_TRGR_9X5	0xC0
131 
132 /* Trigger Register bit field */
133 #define		AT91_ADC_TRGR_TRGPER	(0xffff << 16)
134 #define			AT91_ADC_TRGR_TRGPER_(x)	((x) << 16)
135 #define		AT91_ADC_TRGR_TRGMOD	(0x7 << 0)
136 #define			AT91_ADC_TRGR_NONE		(0 << 0)
137 #define			AT91_ADC_TRGR_MOD_PERIOD_TRIG	(5 << 0)
138 
139 #define AT91_ADC_CHAN(st, ch) \
140 	(st->registers->channel_base + (ch * 4))
141 #define at91_adc_readl(st, reg) \
142 	(readl_relaxed(st->reg_base + reg))
143 #define at91_adc_writel(st, reg, val) \
144 	(writel_relaxed(val, st->reg_base + reg))
145 
146 #define DRIVER_NAME		"at91_adc"
147 #define MAX_POS_BITS		12
148 
149 #define TOUCH_SAMPLE_PERIOD_US		2000	/* 2ms */
150 #define TOUCH_PEN_DETECT_DEBOUNCE_US	200
151 
152 #define MAX_RLPOS_BITS         10
153 #define TOUCH_SAMPLE_PERIOD_US_RL      10000   /* 10ms, the SoC can't keep up with 2ms */
154 #define TOUCH_SHTIM                    0xa
155 #define TOUCH_SCTIM_US		10		/* 10us for the Touchscreen Switches Closure Time */
156 
157 /**
158  * struct at91_adc_reg_desc - Various informations relative to registers
159  * @channel_base:	Base offset for the channel data registers
160  * @drdy_mask:		Mask of the DRDY field in the relevant registers
161 			(Interruptions registers mostly)
162  * @status_register:	Offset of the Interrupt Status Register
163  * @trigger_register:	Offset of the Trigger setup register
164  * @mr_prescal_mask:	Mask of the PRESCAL field in the adc MR register
165  * @mr_startup_mask:	Mask of the STARTUP field in the adc MR register
166  */
167 struct at91_adc_reg_desc {
168 	u8	channel_base;
169 	u32	drdy_mask;
170 	u8	status_register;
171 	u8	trigger_register;
172 	u32	mr_prescal_mask;
173 	u32	mr_startup_mask;
174 };
175 
176 struct at91_adc_caps {
177 	bool	has_ts;		/* Support touch screen */
178 	bool	has_tsmr;	/* only at91sam9x5, sama5d3 have TSMR reg */
179 	/*
180 	 * Numbers of sampling data will be averaged. Can be 0~3.
181 	 * Hardware can average (2 ^ ts_filter_average) sample data.
182 	 */
183 	u8	ts_filter_average;
184 	/* Pen Detection input pull-up resistor, can be 0~3 */
185 	u8	ts_pen_detect_sensitivity;
186 
187 	/* startup time calculate function */
188 	u32 (*calc_startup_ticks)(u32 startup_time, u32 adc_clk_khz);
189 
190 	u8	num_channels;
191 	struct at91_adc_reg_desc registers;
192 };
193 
194 struct at91_adc_state {
195 	struct clk		*adc_clk;
196 	u16			*buffer;
197 	unsigned long		channels_mask;
198 	struct clk		*clk;
199 	bool			done;
200 	int			irq;
201 	u16			last_value;
202 	int			chnb;
203 	struct mutex		lock;
204 	u8			num_channels;
205 	void __iomem		*reg_base;
206 	struct at91_adc_reg_desc *registers;
207 	u32			startup_time;
208 	u8			sample_hold_time;
209 	bool			sleep_mode;
210 	struct iio_trigger	**trig;
211 	struct at91_adc_trigger	*trigger_list;
212 	u32			trigger_number;
213 	bool			use_external;
214 	u32			vref_mv;
215 	u32			res;		/* resolution used for convertions */
216 	bool			low_res;	/* the resolution corresponds to the lowest one */
217 	wait_queue_head_t	wq_data_avail;
218 	struct at91_adc_caps	*caps;
219 
220 	/*
221 	 * Following ADC channels are shared by touchscreen:
222 	 *
223 	 * CH0 -- Touch screen XP/UL
224 	 * CH1 -- Touch screen XM/UR
225 	 * CH2 -- Touch screen YP/LL
226 	 * CH3 -- Touch screen YM/Sense
227 	 * CH4 -- Touch screen LR(5-wire only)
228 	 *
229 	 * The bitfields below represents the reserved channel in the
230 	 * touchscreen mode.
231 	 */
232 #define CHAN_MASK_TOUCHSCREEN_4WIRE	(0xf << 0)
233 #define CHAN_MASK_TOUCHSCREEN_5WIRE	(0x1f << 0)
234 	enum atmel_adc_ts_type	touchscreen_type;
235 	struct input_dev	*ts_input;
236 
237 	u16			ts_sample_period_val;
238 	u32			ts_pressure_threshold;
239 	u16			ts_pendbc;
240 
241 	bool			ts_bufferedmeasure;
242 	u32			ts_prev_absx;
243 	u32			ts_prev_absy;
244 };
245 
246 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
247 {
248 	struct iio_poll_func *pf = p;
249 	struct iio_dev *idev = pf->indio_dev;
250 	struct at91_adc_state *st = iio_priv(idev);
251 	struct iio_chan_spec const *chan;
252 	int i, j = 0;
253 
254 	for (i = 0; i < idev->masklength; i++) {
255 		if (!test_bit(i, idev->active_scan_mask))
256 			continue;
257 		chan = idev->channels + i;
258 		st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, chan->channel));
259 		j++;
260 	}
261 
262 	iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
263 
264 	iio_trigger_notify_done(idev->trig);
265 
266 	/* Needed to ACK the DRDY interruption */
267 	at91_adc_readl(st, AT91_ADC_LCDR);
268 
269 	enable_irq(st->irq);
270 
271 	return IRQ_HANDLED;
272 }
273 
274 /* Handler for classic adc channel eoc trigger */
275 static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
276 {
277 	struct at91_adc_state *st = iio_priv(idev);
278 
279 	if (iio_buffer_enabled(idev)) {
280 		disable_irq_nosync(irq);
281 		iio_trigger_poll(idev->trig);
282 	} else {
283 		st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
284 		/* Needed to ACK the DRDY interruption */
285 		at91_adc_readl(st, AT91_ADC_LCDR);
286 		st->done = true;
287 		wake_up_interruptible(&st->wq_data_avail);
288 	}
289 }
290 
291 static int at91_ts_sample(struct at91_adc_state *st)
292 {
293 	unsigned int xscale, yscale, reg, z1, z2;
294 	unsigned int x, y, pres, xpos, ypos;
295 	unsigned int rxp = 1;
296 	unsigned int factor = 1000;
297 	struct iio_dev *idev = iio_priv_to_dev(st);
298 
299 	unsigned int xyz_mask_bits = st->res;
300 	unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
301 
302 	/* calculate position */
303 	/* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
304 	reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
305 	xpos = reg & xyz_mask;
306 	x = (xpos << MAX_POS_BITS) - xpos;
307 	xscale = (reg >> 16) & xyz_mask;
308 	if (xscale == 0) {
309 		dev_err(&idev->dev, "Error: xscale == 0!\n");
310 		return -1;
311 	}
312 	x /= xscale;
313 
314 	/* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
315 	reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
316 	ypos = reg & xyz_mask;
317 	y = (ypos << MAX_POS_BITS) - ypos;
318 	yscale = (reg >> 16) & xyz_mask;
319 	if (yscale == 0) {
320 		dev_err(&idev->dev, "Error: yscale == 0!\n");
321 		return -1;
322 	}
323 	y /= yscale;
324 
325 	/* calculate the pressure */
326 	reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
327 	z1 = reg & xyz_mask;
328 	z2 = (reg >> 16) & xyz_mask;
329 
330 	if (z1 != 0)
331 		pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
332 			/ factor;
333 	else
334 		pres = st->ts_pressure_threshold;	/* no pen contacted */
335 
336 	dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
337 				xpos, xscale, ypos, yscale, z1, z2, pres);
338 
339 	if (pres < st->ts_pressure_threshold) {
340 		dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
341 					x, y, pres / factor);
342 		input_report_abs(st->ts_input, ABS_X, x);
343 		input_report_abs(st->ts_input, ABS_Y, y);
344 		input_report_abs(st->ts_input, ABS_PRESSURE, pres);
345 		input_report_key(st->ts_input, BTN_TOUCH, 1);
346 		input_sync(st->ts_input);
347 	} else {
348 		dev_dbg(&idev->dev, "pressure too low: not reporting\n");
349 	}
350 
351 	return 0;
352 }
353 
354 static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
355 {
356 	struct iio_dev *idev = private;
357 	struct at91_adc_state *st = iio_priv(idev);
358 	u32 status = at91_adc_readl(st, st->registers->status_register);
359 	unsigned int reg;
360 
361 	status &= at91_adc_readl(st, AT91_ADC_IMR);
362 	if (status & GENMASK(st->num_channels - 1, 0))
363 		handle_adc_eoc_trigger(irq, idev);
364 
365 	if (status & AT91RL_ADC_IER_PEN) {
366 		/* Disabling pen debounce is required to get a NOPEN irq */
367 		reg = at91_adc_readl(st, AT91_ADC_MR);
368 		reg &= ~AT91_ADC_PENDBC;
369 		at91_adc_writel(st, AT91_ADC_MR, reg);
370 
371 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
372 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
373 				| AT91_ADC_EOC(3));
374 		/* Set up period trigger for sampling */
375 		at91_adc_writel(st, st->registers->trigger_register,
376 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
377 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
378 	} else if (status & AT91RL_ADC_IER_NOPEN) {
379 		reg = at91_adc_readl(st, AT91_ADC_MR);
380 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
381 		at91_adc_writel(st, AT91_ADC_MR, reg);
382 		at91_adc_writel(st, st->registers->trigger_register,
383 			AT91_ADC_TRGR_NONE);
384 
385 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
386 				| AT91_ADC_EOC(3));
387 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
388 		st->ts_bufferedmeasure = false;
389 		input_report_key(st->ts_input, BTN_TOUCH, 0);
390 		input_sync(st->ts_input);
391 	} else if (status & AT91_ADC_EOC(3) && st->ts_input) {
392 		/* Conversion finished and we've a touchscreen */
393 		if (st->ts_bufferedmeasure) {
394 			/*
395 			 * Last measurement is always discarded, since it can
396 			 * be erroneous.
397 			 * Always report previous measurement
398 			 */
399 			input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
400 			input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
401 			input_report_key(st->ts_input, BTN_TOUCH, 1);
402 			input_sync(st->ts_input);
403 		} else
404 			st->ts_bufferedmeasure = true;
405 
406 		/* Now make new measurement */
407 		st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
408 				   << MAX_RLPOS_BITS;
409 		st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
410 
411 		st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
412 				   << MAX_RLPOS_BITS;
413 		st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
414 	}
415 
416 	return IRQ_HANDLED;
417 }
418 
419 static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
420 {
421 	struct iio_dev *idev = private;
422 	struct at91_adc_state *st = iio_priv(idev);
423 	u32 status = at91_adc_readl(st, st->registers->status_register);
424 	const uint32_t ts_data_irq_mask =
425 		AT91_ADC_IER_XRDY |
426 		AT91_ADC_IER_YRDY |
427 		AT91_ADC_IER_PRDY;
428 
429 	if (status & GENMASK(st->num_channels - 1, 0))
430 		handle_adc_eoc_trigger(irq, idev);
431 
432 	if (status & AT91_ADC_IER_PEN) {
433 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
434 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
435 			ts_data_irq_mask);
436 		/* Set up period trigger for sampling */
437 		at91_adc_writel(st, st->registers->trigger_register,
438 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
439 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
440 	} else if (status & AT91_ADC_IER_NOPEN) {
441 		at91_adc_writel(st, st->registers->trigger_register, 0);
442 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
443 			ts_data_irq_mask);
444 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
445 
446 		input_report_key(st->ts_input, BTN_TOUCH, 0);
447 		input_sync(st->ts_input);
448 	} else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
449 		/* Now all touchscreen data is ready */
450 
451 		if (status & AT91_ADC_ISR_PENS) {
452 			/* validate data by pen contact */
453 			at91_ts_sample(st);
454 		} else {
455 			/* triggered by event that is no pen contact, just read
456 			 * them to clean the interrupt and discard all.
457 			 */
458 			at91_adc_readl(st, AT91_ADC_TSXPOSR);
459 			at91_adc_readl(st, AT91_ADC_TSYPOSR);
460 			at91_adc_readl(st, AT91_ADC_TSPRESSR);
461 		}
462 	}
463 
464 	return IRQ_HANDLED;
465 }
466 
467 static int at91_adc_channel_init(struct iio_dev *idev)
468 {
469 	struct at91_adc_state *st = iio_priv(idev);
470 	struct iio_chan_spec *chan_array, *timestamp;
471 	int bit, idx = 0;
472 	unsigned long rsvd_mask = 0;
473 
474 	/* If touchscreen is enable, then reserve the adc channels */
475 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
476 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
477 	else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
478 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
479 
480 	/* set up the channel mask to reserve touchscreen channels */
481 	st->channels_mask &= ~rsvd_mask;
482 
483 	idev->num_channels = bitmap_weight(&st->channels_mask,
484 					   st->num_channels) + 1;
485 
486 	chan_array = devm_kzalloc(&idev->dev,
487 				  ((idev->num_channels + 1) *
488 					sizeof(struct iio_chan_spec)),
489 				  GFP_KERNEL);
490 
491 	if (!chan_array)
492 		return -ENOMEM;
493 
494 	for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
495 		struct iio_chan_spec *chan = chan_array + idx;
496 
497 		chan->type = IIO_VOLTAGE;
498 		chan->indexed = 1;
499 		chan->channel = bit;
500 		chan->scan_index = idx;
501 		chan->scan_type.sign = 'u';
502 		chan->scan_type.realbits = st->res;
503 		chan->scan_type.storagebits = 16;
504 		chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
505 		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
506 		idx++;
507 	}
508 	timestamp = chan_array + idx;
509 
510 	timestamp->type = IIO_TIMESTAMP;
511 	timestamp->channel = -1;
512 	timestamp->scan_index = idx;
513 	timestamp->scan_type.sign = 's';
514 	timestamp->scan_type.realbits = 64;
515 	timestamp->scan_type.storagebits = 64;
516 
517 	idev->channels = chan_array;
518 	return idev->num_channels;
519 }
520 
521 static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
522 					     struct at91_adc_trigger *triggers,
523 					     const char *trigger_name)
524 {
525 	struct at91_adc_state *st = iio_priv(idev);
526 	int i;
527 
528 	for (i = 0; i < st->trigger_number; i++) {
529 		char *name = kasprintf(GFP_KERNEL,
530 				"%s-dev%d-%s",
531 				idev->name,
532 				idev->id,
533 				triggers[i].name);
534 		if (!name)
535 			return -ENOMEM;
536 
537 		if (strcmp(trigger_name, name) == 0) {
538 			kfree(name);
539 			if (triggers[i].value == 0)
540 				return -EINVAL;
541 			return triggers[i].value;
542 		}
543 
544 		kfree(name);
545 	}
546 
547 	return -EINVAL;
548 }
549 
550 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
551 {
552 	struct iio_dev *idev = iio_trigger_get_drvdata(trig);
553 	struct at91_adc_state *st = iio_priv(idev);
554 	struct at91_adc_reg_desc *reg = st->registers;
555 	u32 status = at91_adc_readl(st, reg->trigger_register);
556 	int value;
557 	u8 bit;
558 
559 	value = at91_adc_get_trigger_value_by_name(idev,
560 						   st->trigger_list,
561 						   idev->trig->name);
562 	if (value < 0)
563 		return value;
564 
565 	if (state) {
566 		st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
567 		if (st->buffer == NULL)
568 			return -ENOMEM;
569 
570 		at91_adc_writel(st, reg->trigger_register,
571 				status | value);
572 
573 		for_each_set_bit(bit, idev->active_scan_mask,
574 				 st->num_channels) {
575 			struct iio_chan_spec const *chan = idev->channels + bit;
576 			at91_adc_writel(st, AT91_ADC_CHER,
577 					AT91_ADC_CH(chan->channel));
578 		}
579 
580 		at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
581 
582 	} else {
583 		at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
584 
585 		at91_adc_writel(st, reg->trigger_register,
586 				status & ~value);
587 
588 		for_each_set_bit(bit, idev->active_scan_mask,
589 				 st->num_channels) {
590 			struct iio_chan_spec const *chan = idev->channels + bit;
591 			at91_adc_writel(st, AT91_ADC_CHDR,
592 					AT91_ADC_CH(chan->channel));
593 		}
594 		kfree(st->buffer);
595 	}
596 
597 	return 0;
598 }
599 
600 static const struct iio_trigger_ops at91_adc_trigger_ops = {
601 	.set_trigger_state = &at91_adc_configure_trigger,
602 };
603 
604 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
605 						     struct at91_adc_trigger *trigger)
606 {
607 	struct iio_trigger *trig;
608 	int ret;
609 
610 	trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
611 				 idev->id, trigger->name);
612 	if (trig == NULL)
613 		return NULL;
614 
615 	trig->dev.parent = idev->dev.parent;
616 	iio_trigger_set_drvdata(trig, idev);
617 	trig->ops = &at91_adc_trigger_ops;
618 
619 	ret = iio_trigger_register(trig);
620 	if (ret)
621 		return NULL;
622 
623 	return trig;
624 }
625 
626 static int at91_adc_trigger_init(struct iio_dev *idev)
627 {
628 	struct at91_adc_state *st = iio_priv(idev);
629 	int i, ret;
630 
631 	st->trig = devm_kcalloc(&idev->dev,
632 				st->trigger_number, sizeof(*st->trig),
633 				GFP_KERNEL);
634 
635 	if (st->trig == NULL) {
636 		ret = -ENOMEM;
637 		goto error_ret;
638 	}
639 
640 	for (i = 0; i < st->trigger_number; i++) {
641 		if (st->trigger_list[i].is_external && !(st->use_external))
642 			continue;
643 
644 		st->trig[i] = at91_adc_allocate_trigger(idev,
645 							st->trigger_list + i);
646 		if (st->trig[i] == NULL) {
647 			dev_err(&idev->dev,
648 				"Could not allocate trigger %d\n", i);
649 			ret = -ENOMEM;
650 			goto error_trigger;
651 		}
652 	}
653 
654 	return 0;
655 
656 error_trigger:
657 	for (i--; i >= 0; i--) {
658 		iio_trigger_unregister(st->trig[i]);
659 		iio_trigger_free(st->trig[i]);
660 	}
661 error_ret:
662 	return ret;
663 }
664 
665 static void at91_adc_trigger_remove(struct iio_dev *idev)
666 {
667 	struct at91_adc_state *st = iio_priv(idev);
668 	int i;
669 
670 	for (i = 0; i < st->trigger_number; i++) {
671 		iio_trigger_unregister(st->trig[i]);
672 		iio_trigger_free(st->trig[i]);
673 	}
674 }
675 
676 static int at91_adc_buffer_init(struct iio_dev *idev)
677 {
678 	return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
679 		&at91_adc_trigger_handler, NULL);
680 }
681 
682 static void at91_adc_buffer_remove(struct iio_dev *idev)
683 {
684 	iio_triggered_buffer_cleanup(idev);
685 }
686 
687 static int at91_adc_read_raw(struct iio_dev *idev,
688 			     struct iio_chan_spec const *chan,
689 			     int *val, int *val2, long mask)
690 {
691 	struct at91_adc_state *st = iio_priv(idev);
692 	int ret;
693 
694 	switch (mask) {
695 	case IIO_CHAN_INFO_RAW:
696 		mutex_lock(&st->lock);
697 
698 		st->chnb = chan->channel;
699 		at91_adc_writel(st, AT91_ADC_CHER,
700 				AT91_ADC_CH(chan->channel));
701 		at91_adc_writel(st, AT91_ADC_IER, BIT(chan->channel));
702 		at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
703 
704 		ret = wait_event_interruptible_timeout(st->wq_data_avail,
705 						       st->done,
706 						       msecs_to_jiffies(1000));
707 		if (ret == 0)
708 			ret = -ETIMEDOUT;
709 		if (ret < 0) {
710 			mutex_unlock(&st->lock);
711 			return ret;
712 		}
713 
714 		*val = st->last_value;
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 		st->last_value = 0;
721 		st->done = false;
722 		mutex_unlock(&st->lock);
723 		return IIO_VAL_INT;
724 
725 	case IIO_CHAN_INFO_SCALE:
726 		*val = st->vref_mv;
727 		*val2 = chan->scan_type.realbits;
728 		return IIO_VAL_FRACTIONAL_LOG2;
729 	default:
730 		break;
731 	}
732 	return -EINVAL;
733 }
734 
735 static int at91_adc_of_get_resolution(struct at91_adc_state *st,
736 				      struct platform_device *pdev)
737 {
738 	struct iio_dev *idev = iio_priv_to_dev(st);
739 	struct device_node *np = pdev->dev.of_node;
740 	int count, i, ret = 0;
741 	char *res_name, *s;
742 	u32 *resolutions;
743 
744 	count = of_property_count_strings(np, "atmel,adc-res-names");
745 	if (count < 2) {
746 		dev_err(&idev->dev, "You must specified at least two resolution names for "
747 				    "adc-res-names property in the DT\n");
748 		return count;
749 	}
750 
751 	resolutions = kmalloc_array(count, sizeof(*resolutions), GFP_KERNEL);
752 	if (!resolutions)
753 		return -ENOMEM;
754 
755 	if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) {
756 		dev_err(&idev->dev, "Missing adc-res property in the DT.\n");
757 		ret = -ENODEV;
758 		goto ret;
759 	}
760 
761 	if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name))
762 		res_name = "highres";
763 
764 	for (i = 0; i < count; i++) {
765 		if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s))
766 			continue;
767 
768 		if (strcmp(res_name, s))
769 			continue;
770 
771 		st->res = resolutions[i];
772 		if (!strcmp(res_name, "lowres"))
773 			st->low_res = true;
774 		else
775 			st->low_res = false;
776 
777 		dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
778 		goto ret;
779 	}
780 
781 	dev_err(&idev->dev, "There is no resolution for %s\n", res_name);
782 
783 ret:
784 	kfree(resolutions);
785 	return ret;
786 }
787 
788 static u32 calc_startup_ticks_9260(u32 startup_time, u32 adc_clk_khz)
789 {
790 	/*
791 	 * Number of ticks needed to cover the startup time of the ADC
792 	 * as defined in the electrical characteristics of the board,
793 	 * divided by 8. The formula thus is :
794 	 *   Startup Time = (ticks + 1) * 8 / ADC Clock
795 	 */
796 	return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
797 }
798 
799 static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz)
800 {
801 	/*
802 	 * For sama5d3x and at91sam9x5, the formula changes to:
803 	 * Startup Time = <lookup_table_value> / ADC Clock
804 	 */
805 	static const int startup_lookup[] = {
806 		0,   8,   16,  24,
807 		64,  80,  96,  112,
808 		512, 576, 640, 704,
809 		768, 832, 896, 960
810 		};
811 	int i, size = ARRAY_SIZE(startup_lookup);
812 	unsigned int ticks;
813 
814 	ticks = startup_time * adc_clk_khz / 1000;
815 	for (i = 0; i < size; i++)
816 		if (ticks < startup_lookup[i])
817 			break;
818 
819 	ticks = i;
820 	if (ticks == size)
821 		/* Reach the end of lookup table */
822 		ticks = size - 1;
823 
824 	return ticks;
825 }
826 
827 static const struct of_device_id at91_adc_dt_ids[];
828 
829 static int at91_adc_probe_dt_ts(struct device_node *node,
830 	struct at91_adc_state *st, struct device *dev)
831 {
832 	int ret;
833 	u32 prop;
834 
835 	ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
836 	if (ret) {
837 		dev_info(dev, "ADC Touch screen is disabled.\n");
838 		return 0;
839 	}
840 
841 	switch (prop) {
842 	case 4:
843 	case 5:
844 		st->touchscreen_type = prop;
845 		break;
846 	default:
847 		dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
848 		return -EINVAL;
849 	}
850 
851 	if (!st->caps->has_tsmr)
852 		return 0;
853 	prop = 0;
854 	of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
855 	st->ts_pressure_threshold = prop;
856 	if (st->ts_pressure_threshold) {
857 		return 0;
858 	} else {
859 		dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
860 		return -EINVAL;
861 	}
862 }
863 
864 static int at91_adc_probe_dt(struct at91_adc_state *st,
865 			     struct platform_device *pdev)
866 {
867 	struct iio_dev *idev = iio_priv_to_dev(st);
868 	struct device_node *node = pdev->dev.of_node;
869 	struct device_node *trig_node;
870 	int i = 0, ret;
871 	u32 prop;
872 
873 	if (!node)
874 		return -EINVAL;
875 
876 	st->caps = (struct at91_adc_caps *)
877 		of_match_device(at91_adc_dt_ids, &pdev->dev)->data;
878 
879 	st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
880 
881 	if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
882 		dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
883 		ret = -EINVAL;
884 		goto error_ret;
885 	}
886 	st->channels_mask = prop;
887 
888 	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
889 
890 	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
891 		dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
892 		ret = -EINVAL;
893 		goto error_ret;
894 	}
895 	st->startup_time = prop;
896 
897 	prop = 0;
898 	of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
899 	st->sample_hold_time = prop;
900 
901 	if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
902 		dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
903 		ret = -EINVAL;
904 		goto error_ret;
905 	}
906 	st->vref_mv = prop;
907 
908 	ret = at91_adc_of_get_resolution(st, pdev);
909 	if (ret)
910 		goto error_ret;
911 
912 	st->registers = &st->caps->registers;
913 	st->num_channels = st->caps->num_channels;
914 	st->trigger_number = of_get_child_count(node);
915 	st->trigger_list = devm_kcalloc(&idev->dev,
916 					st->trigger_number,
917 					sizeof(struct at91_adc_trigger),
918 					GFP_KERNEL);
919 	if (!st->trigger_list) {
920 		dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
921 		ret = -ENOMEM;
922 		goto error_ret;
923 	}
924 
925 	for_each_child_of_node(node, trig_node) {
926 		struct at91_adc_trigger *trig = st->trigger_list + i;
927 		const char *name;
928 
929 		if (of_property_read_string(trig_node, "trigger-name", &name)) {
930 			dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
931 			ret = -EINVAL;
932 			goto error_ret;
933 		}
934 		trig->name = name;
935 
936 		if (of_property_read_u32(trig_node, "trigger-value", &prop)) {
937 			dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
938 			ret = -EINVAL;
939 			goto error_ret;
940 		}
941 		trig->value = prop;
942 		trig->is_external = of_property_read_bool(trig_node, "trigger-external");
943 		i++;
944 	}
945 
946 	/* Check if touchscreen is supported. */
947 	if (st->caps->has_ts)
948 		return at91_adc_probe_dt_ts(node, st, &idev->dev);
949 	else
950 		dev_info(&idev->dev, "not support touchscreen in the adc compatible string.\n");
951 
952 	return 0;
953 
954 error_ret:
955 	return ret;
956 }
957 
958 static int at91_adc_probe_pdata(struct at91_adc_state *st,
959 				struct platform_device *pdev)
960 {
961 	struct at91_adc_data *pdata = pdev->dev.platform_data;
962 
963 	if (!pdata)
964 		return -EINVAL;
965 
966 	st->caps = (struct at91_adc_caps *)
967 			platform_get_device_id(pdev)->driver_data;
968 
969 	st->use_external = pdata->use_external_triggers;
970 	st->vref_mv = pdata->vref;
971 	st->channels_mask = pdata->channels_used;
972 	st->num_channels = st->caps->num_channels;
973 	st->startup_time = pdata->startup_time;
974 	st->trigger_number = pdata->trigger_number;
975 	st->trigger_list = pdata->trigger_list;
976 	st->registers = &st->caps->registers;
977 	st->touchscreen_type = pdata->touchscreen_type;
978 
979 	return 0;
980 }
981 
982 static const struct iio_info at91_adc_info = {
983 	.read_raw = &at91_adc_read_raw,
984 };
985 
986 /* Touchscreen related functions */
987 static int atmel_ts_open(struct input_dev *dev)
988 {
989 	struct at91_adc_state *st = input_get_drvdata(dev);
990 
991 	if (st->caps->has_tsmr)
992 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
993 	else
994 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
995 	return 0;
996 }
997 
998 static void atmel_ts_close(struct input_dev *dev)
999 {
1000 	struct at91_adc_state *st = input_get_drvdata(dev);
1001 
1002 	if (st->caps->has_tsmr)
1003 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
1004 	else
1005 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
1006 }
1007 
1008 static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
1009 {
1010 	struct iio_dev *idev = iio_priv_to_dev(st);
1011 	u32 reg = 0;
1012 	u32 tssctim = 0;
1013 	int i = 0;
1014 
1015 	/* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
1016 	 * pen detect noise.
1017 	 * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
1018 	 */
1019 	st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
1020 				 1000, 1);
1021 
1022 	while (st->ts_pendbc >> ++i)
1023 		;	/* Empty! Find the shift offset */
1024 	if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
1025 		st->ts_pendbc = i;
1026 	else
1027 		st->ts_pendbc = i - 1;
1028 
1029 	if (!st->caps->has_tsmr) {
1030 		reg = at91_adc_readl(st, AT91_ADC_MR);
1031 		reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
1032 
1033 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
1034 		at91_adc_writel(st, AT91_ADC_MR, reg);
1035 
1036 		reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
1037 		at91_adc_writel(st, AT91_ADC_TSR, reg);
1038 
1039 		st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
1040 						    adc_clk_khz / 1000) - 1, 1);
1041 
1042 		return 0;
1043 	}
1044 
1045 	/* Touchscreen Switches Closure time needed for allowing the value to
1046 	 * stabilize.
1047 	 * Switch Closure Time = (TSSCTIM * 4) ADCClock periods
1048 	 */
1049 	tssctim = DIV_ROUND_UP(TOUCH_SCTIM_US * adc_clk_khz / 1000, 4);
1050 	dev_dbg(&idev->dev, "adc_clk at: %d KHz, tssctim at: %d\n",
1051 		adc_clk_khz, tssctim);
1052 
1053 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
1054 		reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
1055 	else
1056 		reg = AT91_ADC_TSMR_TSMODE_5WIRE;
1057 
1058 	reg |= AT91_ADC_TSMR_SCTIM_(tssctim) & AT91_ADC_TSMR_SCTIM;
1059 	reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
1060 	       & AT91_ADC_TSMR_TSAV;
1061 	reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
1062 	reg |= AT91_ADC_TSMR_NOTSDMA;
1063 	reg |= AT91_ADC_TSMR_PENDET_ENA;
1064 	reg |= 0x03 << 8;	/* TSFREQ, needs to be bigger than TSAV */
1065 
1066 	at91_adc_writel(st, AT91_ADC_TSMR, reg);
1067 
1068 	/* Change adc internal resistor value for better pen detection,
1069 	 * default value is 100 kOhm.
1070 	 * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
1071 	 * option only available on ES2 and higher
1072 	 */
1073 	at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
1074 			& AT91_ADC_ACR_PENDETSENS);
1075 
1076 	/* Sample Period Time = (TRGPER + 1) / ADCClock */
1077 	st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
1078 			adc_clk_khz / 1000) - 1, 1);
1079 
1080 	return 0;
1081 }
1082 
1083 static int at91_ts_register(struct at91_adc_state *st,
1084 		struct platform_device *pdev)
1085 {
1086 	struct input_dev *input;
1087 	struct iio_dev *idev = iio_priv_to_dev(st);
1088 	int ret;
1089 
1090 	input = input_allocate_device();
1091 	if (!input) {
1092 		dev_err(&idev->dev, "Failed to allocate TS device!\n");
1093 		return -ENOMEM;
1094 	}
1095 
1096 	input->name = DRIVER_NAME;
1097 	input->id.bustype = BUS_HOST;
1098 	input->dev.parent = &pdev->dev;
1099 	input->open = atmel_ts_open;
1100 	input->close = atmel_ts_close;
1101 
1102 	__set_bit(EV_ABS, input->evbit);
1103 	__set_bit(EV_KEY, input->evbit);
1104 	__set_bit(BTN_TOUCH, input->keybit);
1105 	if (st->caps->has_tsmr) {
1106 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
1107 				     0, 0);
1108 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
1109 				     0, 0);
1110 		input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
1111 	} else {
1112 		if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
1113 			dev_err(&pdev->dev,
1114 				"This touchscreen controller only support 4 wires\n");
1115 			ret = -EINVAL;
1116 			goto err;
1117 		}
1118 
1119 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
1120 				     0, 0);
1121 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
1122 				     0, 0);
1123 	}
1124 
1125 	st->ts_input = input;
1126 	input_set_drvdata(input, st);
1127 
1128 	ret = input_register_device(input);
1129 	if (ret)
1130 		goto err;
1131 
1132 	return ret;
1133 
1134 err:
1135 	input_free_device(st->ts_input);
1136 	return ret;
1137 }
1138 
1139 static void at91_ts_unregister(struct at91_adc_state *st)
1140 {
1141 	input_unregister_device(st->ts_input);
1142 }
1143 
1144 static int at91_adc_probe(struct platform_device *pdev)
1145 {
1146 	unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
1147 	int ret;
1148 	struct iio_dev *idev;
1149 	struct at91_adc_state *st;
1150 	struct resource *res;
1151 	u32 reg;
1152 
1153 	idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
1154 	if (!idev)
1155 		return -ENOMEM;
1156 
1157 	st = iio_priv(idev);
1158 
1159 	if (pdev->dev.of_node)
1160 		ret = at91_adc_probe_dt(st, pdev);
1161 	else
1162 		ret = at91_adc_probe_pdata(st, pdev);
1163 
1164 	if (ret) {
1165 		dev_err(&pdev->dev, "No platform data available.\n");
1166 		return -EINVAL;
1167 	}
1168 
1169 	platform_set_drvdata(pdev, idev);
1170 
1171 	idev->dev.parent = &pdev->dev;
1172 	idev->name = dev_name(&pdev->dev);
1173 	idev->modes = INDIO_DIRECT_MODE;
1174 	idev->info = &at91_adc_info;
1175 
1176 	st->irq = platform_get_irq(pdev, 0);
1177 	if (st->irq < 0) {
1178 		dev_err(&pdev->dev, "No IRQ ID is designated\n");
1179 		return -ENODEV;
1180 	}
1181 
1182 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1183 
1184 	st->reg_base = devm_ioremap_resource(&pdev->dev, res);
1185 	if (IS_ERR(st->reg_base))
1186 		return PTR_ERR(st->reg_base);
1187 
1188 
1189 	/*
1190 	 * Disable all IRQs before setting up the handler
1191 	 */
1192 	at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
1193 	at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
1194 
1195 	if (st->caps->has_tsmr)
1196 		ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0,
1197 				  pdev->dev.driver->name, idev);
1198 	else
1199 		ret = request_irq(st->irq, at91_adc_rl_interrupt, 0,
1200 				  pdev->dev.driver->name, idev);
1201 	if (ret) {
1202 		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
1203 		return ret;
1204 	}
1205 
1206 	st->clk = devm_clk_get(&pdev->dev, "adc_clk");
1207 	if (IS_ERR(st->clk)) {
1208 		dev_err(&pdev->dev, "Failed to get the clock.\n");
1209 		ret = PTR_ERR(st->clk);
1210 		goto error_free_irq;
1211 	}
1212 
1213 	ret = clk_prepare_enable(st->clk);
1214 	if (ret) {
1215 		dev_err(&pdev->dev,
1216 			"Could not prepare or enable the clock.\n");
1217 		goto error_free_irq;
1218 	}
1219 
1220 	st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
1221 	if (IS_ERR(st->adc_clk)) {
1222 		dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
1223 		ret = PTR_ERR(st->adc_clk);
1224 		goto error_disable_clk;
1225 	}
1226 
1227 	ret = clk_prepare_enable(st->adc_clk);
1228 	if (ret) {
1229 		dev_err(&pdev->dev,
1230 			"Could not prepare or enable the ADC clock.\n");
1231 		goto error_disable_clk;
1232 	}
1233 
1234 	/*
1235 	 * Prescaler rate computation using the formula from the Atmel's
1236 	 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
1237 	 * specified by the electrical characteristics of the board.
1238 	 */
1239 	mstrclk = clk_get_rate(st->clk);
1240 	adc_clk = clk_get_rate(st->adc_clk);
1241 	adc_clk_khz = adc_clk / 1000;
1242 
1243 	dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
1244 		mstrclk, adc_clk);
1245 
1246 	prsc = (mstrclk / (2 * adc_clk)) - 1;
1247 
1248 	if (!st->startup_time) {
1249 		dev_err(&pdev->dev, "No startup time available.\n");
1250 		ret = -EINVAL;
1251 		goto error_disable_adc_clk;
1252 	}
1253 	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
1254 
1255 	/*
1256 	 * a minimal Sample and Hold Time is necessary for the ADC to guarantee
1257 	 * the best converted final value between two channels selection
1258 	 * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
1259 	 */
1260 	if (st->sample_hold_time > 0)
1261 		shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000)
1262 				 - 1, 1);
1263 	else
1264 		shtim = 0;
1265 
1266 	reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
1267 	reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
1268 	if (st->low_res)
1269 		reg |= AT91_ADC_LOWRES;
1270 	if (st->sleep_mode)
1271 		reg |= AT91_ADC_SLEEP;
1272 	reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
1273 	at91_adc_writel(st, AT91_ADC_MR, reg);
1274 
1275 	/* Setup the ADC channels available on the board */
1276 	ret = at91_adc_channel_init(idev);
1277 	if (ret < 0) {
1278 		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
1279 		goto error_disable_adc_clk;
1280 	}
1281 
1282 	init_waitqueue_head(&st->wq_data_avail);
1283 	mutex_init(&st->lock);
1284 
1285 	/*
1286 	 * Since touch screen will set trigger register as period trigger. So
1287 	 * when touch screen is enabled, then we have to disable hardware
1288 	 * trigger for classic adc.
1289 	 */
1290 	if (!st->touchscreen_type) {
1291 		ret = at91_adc_buffer_init(idev);
1292 		if (ret < 0) {
1293 			dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
1294 			goto error_disable_adc_clk;
1295 		}
1296 
1297 		ret = at91_adc_trigger_init(idev);
1298 		if (ret < 0) {
1299 			dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
1300 			at91_adc_buffer_remove(idev);
1301 			goto error_disable_adc_clk;
1302 		}
1303 	} else {
1304 		ret = at91_ts_register(st, pdev);
1305 		if (ret)
1306 			goto error_disable_adc_clk;
1307 
1308 		at91_ts_hw_init(st, adc_clk_khz);
1309 	}
1310 
1311 	ret = iio_device_register(idev);
1312 	if (ret < 0) {
1313 		dev_err(&pdev->dev, "Couldn't register the device.\n");
1314 		goto error_iio_device_register;
1315 	}
1316 
1317 	return 0;
1318 
1319 error_iio_device_register:
1320 	if (!st->touchscreen_type) {
1321 		at91_adc_trigger_remove(idev);
1322 		at91_adc_buffer_remove(idev);
1323 	} else {
1324 		at91_ts_unregister(st);
1325 	}
1326 error_disable_adc_clk:
1327 	clk_disable_unprepare(st->adc_clk);
1328 error_disable_clk:
1329 	clk_disable_unprepare(st->clk);
1330 error_free_irq:
1331 	free_irq(st->irq, idev);
1332 	return ret;
1333 }
1334 
1335 static int at91_adc_remove(struct platform_device *pdev)
1336 {
1337 	struct iio_dev *idev = platform_get_drvdata(pdev);
1338 	struct at91_adc_state *st = iio_priv(idev);
1339 
1340 	iio_device_unregister(idev);
1341 	if (!st->touchscreen_type) {
1342 		at91_adc_trigger_remove(idev);
1343 		at91_adc_buffer_remove(idev);
1344 	} else {
1345 		at91_ts_unregister(st);
1346 	}
1347 	clk_disable_unprepare(st->adc_clk);
1348 	clk_disable_unprepare(st->clk);
1349 	free_irq(st->irq, idev);
1350 
1351 	return 0;
1352 }
1353 
1354 #ifdef CONFIG_PM_SLEEP
1355 static int at91_adc_suspend(struct device *dev)
1356 {
1357 	struct iio_dev *idev = platform_get_drvdata(to_platform_device(dev));
1358 	struct at91_adc_state *st = iio_priv(idev);
1359 
1360 	pinctrl_pm_select_sleep_state(dev);
1361 	clk_disable_unprepare(st->clk);
1362 
1363 	return 0;
1364 }
1365 
1366 static int at91_adc_resume(struct device *dev)
1367 {
1368 	struct iio_dev *idev = platform_get_drvdata(to_platform_device(dev));
1369 	struct at91_adc_state *st = iio_priv(idev);
1370 
1371 	clk_prepare_enable(st->clk);
1372 	pinctrl_pm_select_default_state(dev);
1373 
1374 	return 0;
1375 }
1376 #endif
1377 
1378 static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume);
1379 
1380 static struct at91_adc_caps at91sam9260_caps = {
1381 	.calc_startup_ticks = calc_startup_ticks_9260,
1382 	.num_channels = 4,
1383 	.registers = {
1384 		.channel_base = AT91_ADC_CHR(0),
1385 		.drdy_mask = AT91_ADC_DRDY,
1386 		.status_register = AT91_ADC_SR,
1387 		.trigger_register = AT91_ADC_TRGR_9260,
1388 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1389 		.mr_startup_mask = AT91_ADC_STARTUP_9260,
1390 	},
1391 };
1392 
1393 static struct at91_adc_caps at91sam9rl_caps = {
1394 	.has_ts = true,
1395 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1396 	.num_channels = 6,
1397 	.registers = {
1398 		.channel_base = AT91_ADC_CHR(0),
1399 		.drdy_mask = AT91_ADC_DRDY,
1400 		.status_register = AT91_ADC_SR,
1401 		.trigger_register = AT91_ADC_TRGR_9G45,
1402 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1403 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1404 	},
1405 };
1406 
1407 static struct at91_adc_caps at91sam9g45_caps = {
1408 	.has_ts = true,
1409 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1410 	.num_channels = 8,
1411 	.registers = {
1412 		.channel_base = AT91_ADC_CHR(0),
1413 		.drdy_mask = AT91_ADC_DRDY,
1414 		.status_register = AT91_ADC_SR,
1415 		.trigger_register = AT91_ADC_TRGR_9G45,
1416 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1417 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1418 	},
1419 };
1420 
1421 static struct at91_adc_caps at91sam9x5_caps = {
1422 	.has_ts = true,
1423 	.has_tsmr = true,
1424 	.ts_filter_average = 3,
1425 	.ts_pen_detect_sensitivity = 2,
1426 	.calc_startup_ticks = calc_startup_ticks_9x5,
1427 	.num_channels = 12,
1428 	.registers = {
1429 		.channel_base = AT91_ADC_CDR0_9X5,
1430 		.drdy_mask = AT91_ADC_SR_DRDY_9X5,
1431 		.status_register = AT91_ADC_SR_9X5,
1432 		.trigger_register = AT91_ADC_TRGR_9X5,
1433 		/* prescal mask is same as 9G45 */
1434 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1435 		.mr_startup_mask = AT91_ADC_STARTUP_9X5,
1436 	},
1437 };
1438 
1439 static const struct of_device_id at91_adc_dt_ids[] = {
1440 	{ .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
1441 	{ .compatible = "atmel,at91sam9rl-adc", .data = &at91sam9rl_caps },
1442 	{ .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
1443 	{ .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
1444 	{},
1445 };
1446 MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
1447 
1448 static const struct platform_device_id at91_adc_ids[] = {
1449 	{
1450 		.name = "at91sam9260-adc",
1451 		.driver_data = (unsigned long)&at91sam9260_caps,
1452 	}, {
1453 		.name = "at91sam9rl-adc",
1454 		.driver_data = (unsigned long)&at91sam9rl_caps,
1455 	}, {
1456 		.name = "at91sam9g45-adc",
1457 		.driver_data = (unsigned long)&at91sam9g45_caps,
1458 	}, {
1459 		.name = "at91sam9x5-adc",
1460 		.driver_data = (unsigned long)&at91sam9x5_caps,
1461 	}, {
1462 		/* terminator */
1463 	}
1464 };
1465 MODULE_DEVICE_TABLE(platform, at91_adc_ids);
1466 
1467 static struct platform_driver at91_adc_driver = {
1468 	.probe = at91_adc_probe,
1469 	.remove = at91_adc_remove,
1470 	.id_table = at91_adc_ids,
1471 	.driver = {
1472 		   .name = DRIVER_NAME,
1473 		   .of_match_table = of_match_ptr(at91_adc_dt_ids),
1474 		   .pm = &at91_adc_pm_ops,
1475 	},
1476 };
1477 
1478 module_platform_driver(at91_adc_driver);
1479 
1480 MODULE_LICENSE("GPL");
1481 MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
1482 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1483