xref: /openbmc/linux/drivers/iio/adc/at91_adc.c (revision 6c33a6f4)
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/of_device.h>
20 #include <linux/platform_device.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/wait.h>
24 
25 #include <linux/platform_data/at91_adc.h>
26 
27 #include <linux/iio/iio.h>
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/trigger.h>
30 #include <linux/iio/trigger_consumer.h>
31 #include <linux/iio/triggered_buffer.h>
32 #include <linux/pinctrl/consumer.h>
33 
34 /* Registers */
35 #define AT91_ADC_CR		0x00		/* Control Register */
36 #define		AT91_ADC_SWRST		(1 << 0)	/* Software Reset */
37 #define		AT91_ADC_START		(1 << 1)	/* Start Conversion */
38 
39 #define AT91_ADC_MR		0x04		/* Mode Register */
40 #define		AT91_ADC_TSAMOD		(3 << 0)	/* ADC mode */
41 #define		AT91_ADC_TSAMOD_ADC_ONLY_MODE		(0 << 0)	/* ADC Mode */
42 #define		AT91_ADC_TSAMOD_TS_ONLY_MODE		(1 << 0)	/* Touch Screen Only Mode */
43 #define		AT91_ADC_TRGEN		(1 << 0)	/* Trigger Enable */
44 #define		AT91_ADC_TRGSEL		(7 << 1)	/* Trigger Selection */
45 #define			AT91_ADC_TRGSEL_TC0		(0 << 1)
46 #define			AT91_ADC_TRGSEL_TC1		(1 << 1)
47 #define			AT91_ADC_TRGSEL_TC2		(2 << 1)
48 #define			AT91_ADC_TRGSEL_EXTERNAL	(6 << 1)
49 #define		AT91_ADC_LOWRES		(1 << 4)	/* Low Resolution */
50 #define		AT91_ADC_SLEEP		(1 << 5)	/* Sleep Mode */
51 #define		AT91_ADC_PENDET		(1 << 6)	/* Pen contact detection enable */
52 #define		AT91_ADC_PRESCAL_9260	(0x3f << 8)	/* Prescalar Rate Selection */
53 #define		AT91_ADC_PRESCAL_9G45	(0xff << 8)
54 #define			AT91_ADC_PRESCAL_(x)	((x) << 8)
55 #define		AT91_ADC_STARTUP_9260	(0x1f << 16)	/* Startup Up Time */
56 #define		AT91_ADC_STARTUP_9G45	(0x7f << 16)
57 #define		AT91_ADC_STARTUP_9X5	(0xf << 16)
58 #define			AT91_ADC_STARTUP_(x)	((x) << 16)
59 #define		AT91_ADC_SHTIM		(0xf  << 24)	/* Sample & Hold Time */
60 #define			AT91_ADC_SHTIM_(x)	((x) << 24)
61 #define		AT91_ADC_PENDBC		(0x0f << 28)	/* Pen Debounce time */
62 #define			AT91_ADC_PENDBC_(x)	((x) << 28)
63 
64 #define AT91_ADC_TSR		0x0C
65 #define		AT91_ADC_TSR_SHTIM	(0xf  << 24)	/* Sample & Hold Time */
66 #define			AT91_ADC_TSR_SHTIM_(x)	((x) << 24)
67 
68 #define AT91_ADC_CHER		0x10		/* Channel Enable Register */
69 #define AT91_ADC_CHDR		0x14		/* Channel Disable Register */
70 #define AT91_ADC_CHSR		0x18		/* Channel Status Register */
71 #define		AT91_ADC_CH(n)		(1 << (n))	/* Channel Number */
72 
73 #define AT91_ADC_SR		0x1C		/* Status Register */
74 #define		AT91_ADC_EOC(n)		(1 << (n))	/* End of Conversion on Channel N */
75 #define		AT91_ADC_OVRE(n)	(1 << ((n) + 8))/* Overrun Error on Channel N */
76 #define		AT91_ADC_DRDY		(1 << 16)	/* Data Ready */
77 #define		AT91_ADC_GOVRE		(1 << 17)	/* General Overrun Error */
78 #define		AT91_ADC_ENDRX		(1 << 18)	/* End of RX Buffer */
79 #define		AT91_ADC_RXFUFF		(1 << 19)	/* RX Buffer Full */
80 
81 #define AT91_ADC_SR_9X5		0x30		/* Status Register for 9x5 */
82 #define		AT91_ADC_SR_DRDY_9X5	(1 << 24)	/* Data Ready */
83 
84 #define AT91_ADC_LCDR		0x20		/* Last Converted Data Register */
85 #define		AT91_ADC_LDATA		(0x3ff)
86 
87 #define AT91_ADC_IER		0x24		/* Interrupt Enable Register */
88 #define AT91_ADC_IDR		0x28		/* Interrupt Disable Register */
89 #define AT91_ADC_IMR		0x2C		/* Interrupt Mask Register */
90 #define		AT91RL_ADC_IER_PEN	(1 << 20)
91 #define		AT91RL_ADC_IER_NOPEN	(1 << 21)
92 #define		AT91_ADC_IER_PEN	(1 << 29)
93 #define		AT91_ADC_IER_NOPEN	(1 << 30)
94 #define		AT91_ADC_IER_XRDY	(1 << 20)
95 #define		AT91_ADC_IER_YRDY	(1 << 21)
96 #define		AT91_ADC_IER_PRDY	(1 << 22)
97 #define		AT91_ADC_ISR_PENS	(1 << 31)
98 
99 #define AT91_ADC_CHR(n)		(0x30 + ((n) * 4))	/* Channel Data Register N */
100 #define		AT91_ADC_DATA		(0x3ff)
101 
102 #define AT91_ADC_CDR0_9X5	(0x50)			/* Channel Data Register 0 for 9X5 */
103 
104 #define AT91_ADC_ACR		0x94	/* Analog Control Register */
105 #define		AT91_ADC_ACR_PENDETSENS	(0x3 << 0)	/* pull-up resistor */
106 
107 #define AT91_ADC_TSMR		0xB0
108 #define		AT91_ADC_TSMR_TSMODE	(3 << 0)	/* Touch Screen Mode */
109 #define			AT91_ADC_TSMR_TSMODE_NONE		(0 << 0)
110 #define			AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS	(1 << 0)
111 #define			AT91_ADC_TSMR_TSMODE_4WIRE_PRESS	(2 << 0)
112 #define			AT91_ADC_TSMR_TSMODE_5WIRE		(3 << 0)
113 #define		AT91_ADC_TSMR_TSAV	(3 << 4)	/* Averages samples */
114 #define			AT91_ADC_TSMR_TSAV_(x)		((x) << 4)
115 #define		AT91_ADC_TSMR_SCTIM	(0x0f << 16)	/* Switch closure time */
116 #define			AT91_ADC_TSMR_SCTIM_(x)		((x) << 16)
117 #define		AT91_ADC_TSMR_PENDBC	(0x0f << 28)	/* Pen Debounce time */
118 #define			AT91_ADC_TSMR_PENDBC_(x)	((x) << 28)
119 #define		AT91_ADC_TSMR_NOTSDMA	(1 << 22)	/* No Touchscreen DMA */
120 #define		AT91_ADC_TSMR_PENDET_DIS	(0 << 24)	/* Pen contact detection disable */
121 #define		AT91_ADC_TSMR_PENDET_ENA	(1 << 24)	/* Pen contact detection enable */
122 
123 #define AT91_ADC_TSXPOSR	0xB4
124 #define AT91_ADC_TSYPOSR	0xB8
125 #define AT91_ADC_TSPRESSR	0xBC
126 
127 #define AT91_ADC_TRGR_9260	AT91_ADC_MR
128 #define AT91_ADC_TRGR_9G45	0x08
129 #define AT91_ADC_TRGR_9X5	0xC0
130 
131 /* Trigger Register bit field */
132 #define		AT91_ADC_TRGR_TRGPER	(0xffff << 16)
133 #define			AT91_ADC_TRGR_TRGPER_(x)	((x) << 16)
134 #define		AT91_ADC_TRGR_TRGMOD	(0x7 << 0)
135 #define			AT91_ADC_TRGR_NONE		(0 << 0)
136 #define			AT91_ADC_TRGR_MOD_PERIOD_TRIG	(5 << 0)
137 
138 #define AT91_ADC_CHAN(st, ch) \
139 	(st->registers->channel_base + (ch * 4))
140 #define at91_adc_readl(st, reg) \
141 	(readl_relaxed(st->reg_base + reg))
142 #define at91_adc_writel(st, reg, val) \
143 	(writel_relaxed(val, st->reg_base + reg))
144 
145 #define DRIVER_NAME		"at91_adc"
146 #define MAX_POS_BITS		12
147 
148 #define TOUCH_SAMPLE_PERIOD_US		2000	/* 2ms */
149 #define TOUCH_PEN_DETECT_DEBOUNCE_US	200
150 
151 #define MAX_RLPOS_BITS         10
152 #define TOUCH_SAMPLE_PERIOD_US_RL      10000   /* 10ms, the SoC can't keep up with 2ms */
153 #define TOUCH_SHTIM                    0xa
154 #define TOUCH_SCTIM_US		10		/* 10us for the Touchscreen Switches Closure Time */
155 
156 /**
157  * struct at91_adc_reg_desc - Various informations relative to registers
158  * @channel_base:	Base offset for the channel data registers
159  * @drdy_mask:		Mask of the DRDY field in the relevant registers
160 			(Interruptions registers mostly)
161  * @status_register:	Offset of the Interrupt Status Register
162  * @trigger_register:	Offset of the Trigger setup register
163  * @mr_prescal_mask:	Mask of the PRESCAL field in the adc MR register
164  * @mr_startup_mask:	Mask of the STARTUP field in the adc MR register
165  */
166 struct at91_adc_reg_desc {
167 	u8	channel_base;
168 	u32	drdy_mask;
169 	u8	status_register;
170 	u8	trigger_register;
171 	u32	mr_prescal_mask;
172 	u32	mr_startup_mask;
173 };
174 
175 struct at91_adc_caps {
176 	bool	has_ts;		/* Support touch screen */
177 	bool	has_tsmr;	/* only at91sam9x5, sama5d3 have TSMR reg */
178 	/*
179 	 * Numbers of sampling data will be averaged. Can be 0~3.
180 	 * Hardware can average (2 ^ ts_filter_average) sample data.
181 	 */
182 	u8	ts_filter_average;
183 	/* Pen Detection input pull-up resistor, can be 0~3 */
184 	u8	ts_pen_detect_sensitivity;
185 
186 	/* startup time calculate function */
187 	u32 (*calc_startup_ticks)(u32 startup_time, u32 adc_clk_khz);
188 
189 	u8	num_channels;
190 	struct at91_adc_reg_desc registers;
191 };
192 
193 struct at91_adc_state {
194 	struct clk		*adc_clk;
195 	u16			*buffer;
196 	unsigned long		channels_mask;
197 	struct clk		*clk;
198 	bool			done;
199 	int			irq;
200 	u16			last_value;
201 	int			chnb;
202 	struct mutex		lock;
203 	u8			num_channels;
204 	void __iomem		*reg_base;
205 	struct at91_adc_reg_desc *registers;
206 	u32			startup_time;
207 	u8			sample_hold_time;
208 	bool			sleep_mode;
209 	struct iio_trigger	**trig;
210 	struct at91_adc_trigger	*trigger_list;
211 	u32			trigger_number;
212 	bool			use_external;
213 	u32			vref_mv;
214 	u32			res;		/* resolution used for convertions */
215 	bool			low_res;	/* the resolution corresponds to the lowest one */
216 	wait_queue_head_t	wq_data_avail;
217 	struct at91_adc_caps	*caps;
218 
219 	/*
220 	 * Following ADC channels are shared by touchscreen:
221 	 *
222 	 * CH0 -- Touch screen XP/UL
223 	 * CH1 -- Touch screen XM/UR
224 	 * CH2 -- Touch screen YP/LL
225 	 * CH3 -- Touch screen YM/Sense
226 	 * CH4 -- Touch screen LR(5-wire only)
227 	 *
228 	 * The bitfields below represents the reserved channel in the
229 	 * touchscreen mode.
230 	 */
231 #define CHAN_MASK_TOUCHSCREEN_4WIRE	(0xf << 0)
232 #define CHAN_MASK_TOUCHSCREEN_5WIRE	(0x1f << 0)
233 	enum atmel_adc_ts_type	touchscreen_type;
234 	struct input_dev	*ts_input;
235 
236 	u16			ts_sample_period_val;
237 	u32			ts_pressure_threshold;
238 	u16			ts_pendbc;
239 
240 	bool			ts_bufferedmeasure;
241 	u32			ts_prev_absx;
242 	u32			ts_prev_absy;
243 };
244 
245 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
246 {
247 	struct iio_poll_func *pf = p;
248 	struct iio_dev *idev = pf->indio_dev;
249 	struct at91_adc_state *st = iio_priv(idev);
250 	struct iio_chan_spec const *chan;
251 	int i, j = 0;
252 
253 	for (i = 0; i < idev->masklength; i++) {
254 		if (!test_bit(i, idev->active_scan_mask))
255 			continue;
256 		chan = idev->channels + i;
257 		st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, chan->channel));
258 		j++;
259 	}
260 
261 	iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
262 
263 	iio_trigger_notify_done(idev->trig);
264 
265 	/* Needed to ACK the DRDY interruption */
266 	at91_adc_readl(st, AT91_ADC_LCDR);
267 
268 	enable_irq(st->irq);
269 
270 	return IRQ_HANDLED;
271 }
272 
273 /* Handler for classic adc channel eoc trigger */
274 static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
275 {
276 	struct at91_adc_state *st = iio_priv(idev);
277 
278 	if (iio_buffer_enabled(idev)) {
279 		disable_irq_nosync(irq);
280 		iio_trigger_poll(idev->trig);
281 	} else {
282 		st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
283 		/* Needed to ACK the DRDY interruption */
284 		at91_adc_readl(st, AT91_ADC_LCDR);
285 		st->done = true;
286 		wake_up_interruptible(&st->wq_data_avail);
287 	}
288 }
289 
290 static int at91_ts_sample(struct at91_adc_state *st)
291 {
292 	unsigned int xscale, yscale, reg, z1, z2;
293 	unsigned int x, y, pres, xpos, ypos;
294 	unsigned int rxp = 1;
295 	unsigned int factor = 1000;
296 	struct iio_dev *idev = iio_priv_to_dev(st);
297 
298 	unsigned int xyz_mask_bits = st->res;
299 	unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
300 
301 	/* calculate position */
302 	/* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
303 	reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
304 	xpos = reg & xyz_mask;
305 	x = (xpos << MAX_POS_BITS) - xpos;
306 	xscale = (reg >> 16) & xyz_mask;
307 	if (xscale == 0) {
308 		dev_err(&idev->dev, "Error: xscale == 0!\n");
309 		return -1;
310 	}
311 	x /= xscale;
312 
313 	/* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
314 	reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
315 	ypos = reg & xyz_mask;
316 	y = (ypos << MAX_POS_BITS) - ypos;
317 	yscale = (reg >> 16) & xyz_mask;
318 	if (yscale == 0) {
319 		dev_err(&idev->dev, "Error: yscale == 0!\n");
320 		return -1;
321 	}
322 	y /= yscale;
323 
324 	/* calculate the pressure */
325 	reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
326 	z1 = reg & xyz_mask;
327 	z2 = (reg >> 16) & xyz_mask;
328 
329 	if (z1 != 0)
330 		pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
331 			/ factor;
332 	else
333 		pres = st->ts_pressure_threshold;	/* no pen contacted */
334 
335 	dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
336 				xpos, xscale, ypos, yscale, z1, z2, pres);
337 
338 	if (pres < st->ts_pressure_threshold) {
339 		dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
340 					x, y, pres / factor);
341 		input_report_abs(st->ts_input, ABS_X, x);
342 		input_report_abs(st->ts_input, ABS_Y, y);
343 		input_report_abs(st->ts_input, ABS_PRESSURE, pres);
344 		input_report_key(st->ts_input, BTN_TOUCH, 1);
345 		input_sync(st->ts_input);
346 	} else {
347 		dev_dbg(&idev->dev, "pressure too low: not reporting\n");
348 	}
349 
350 	return 0;
351 }
352 
353 static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
354 {
355 	struct iio_dev *idev = private;
356 	struct at91_adc_state *st = iio_priv(idev);
357 	u32 status = at91_adc_readl(st, st->registers->status_register);
358 	unsigned int reg;
359 
360 	status &= at91_adc_readl(st, AT91_ADC_IMR);
361 	if (status & GENMASK(st->num_channels - 1, 0))
362 		handle_adc_eoc_trigger(irq, idev);
363 
364 	if (status & AT91RL_ADC_IER_PEN) {
365 		/* Disabling pen debounce is required to get a NOPEN irq */
366 		reg = at91_adc_readl(st, AT91_ADC_MR);
367 		reg &= ~AT91_ADC_PENDBC;
368 		at91_adc_writel(st, AT91_ADC_MR, reg);
369 
370 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
371 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
372 				| AT91_ADC_EOC(3));
373 		/* Set up period trigger for sampling */
374 		at91_adc_writel(st, st->registers->trigger_register,
375 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
376 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
377 	} else if (status & AT91RL_ADC_IER_NOPEN) {
378 		reg = at91_adc_readl(st, AT91_ADC_MR);
379 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
380 		at91_adc_writel(st, AT91_ADC_MR, reg);
381 		at91_adc_writel(st, st->registers->trigger_register,
382 			AT91_ADC_TRGR_NONE);
383 
384 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
385 				| AT91_ADC_EOC(3));
386 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
387 		st->ts_bufferedmeasure = false;
388 		input_report_key(st->ts_input, BTN_TOUCH, 0);
389 		input_sync(st->ts_input);
390 	} else if (status & AT91_ADC_EOC(3) && st->ts_input) {
391 		/* Conversion finished and we've a touchscreen */
392 		if (st->ts_bufferedmeasure) {
393 			/*
394 			 * Last measurement is always discarded, since it can
395 			 * be erroneous.
396 			 * Always report previous measurement
397 			 */
398 			input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
399 			input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
400 			input_report_key(st->ts_input, BTN_TOUCH, 1);
401 			input_sync(st->ts_input);
402 		} else
403 			st->ts_bufferedmeasure = true;
404 
405 		/* Now make new measurement */
406 		st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
407 				   << MAX_RLPOS_BITS;
408 		st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
409 
410 		st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
411 				   << MAX_RLPOS_BITS;
412 		st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
413 	}
414 
415 	return IRQ_HANDLED;
416 }
417 
418 static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
419 {
420 	struct iio_dev *idev = private;
421 	struct at91_adc_state *st = iio_priv(idev);
422 	u32 status = at91_adc_readl(st, st->registers->status_register);
423 	const uint32_t ts_data_irq_mask =
424 		AT91_ADC_IER_XRDY |
425 		AT91_ADC_IER_YRDY |
426 		AT91_ADC_IER_PRDY;
427 
428 	if (status & GENMASK(st->num_channels - 1, 0))
429 		handle_adc_eoc_trigger(irq, idev);
430 
431 	if (status & AT91_ADC_IER_PEN) {
432 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
433 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
434 			ts_data_irq_mask);
435 		/* Set up period trigger for sampling */
436 		at91_adc_writel(st, st->registers->trigger_register,
437 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
438 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
439 	} else if (status & AT91_ADC_IER_NOPEN) {
440 		at91_adc_writel(st, st->registers->trigger_register, 0);
441 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
442 			ts_data_irq_mask);
443 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
444 
445 		input_report_key(st->ts_input, BTN_TOUCH, 0);
446 		input_sync(st->ts_input);
447 	} else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
448 		/* Now all touchscreen data is ready */
449 
450 		if (status & AT91_ADC_ISR_PENS) {
451 			/* validate data by pen contact */
452 			at91_ts_sample(st);
453 		} else {
454 			/* triggered by event that is no pen contact, just read
455 			 * them to clean the interrupt and discard all.
456 			 */
457 			at91_adc_readl(st, AT91_ADC_TSXPOSR);
458 			at91_adc_readl(st, AT91_ADC_TSYPOSR);
459 			at91_adc_readl(st, AT91_ADC_TSPRESSR);
460 		}
461 	}
462 
463 	return IRQ_HANDLED;
464 }
465 
466 static int at91_adc_channel_init(struct iio_dev *idev)
467 {
468 	struct at91_adc_state *st = iio_priv(idev);
469 	struct iio_chan_spec *chan_array, *timestamp;
470 	int bit, idx = 0;
471 	unsigned long rsvd_mask = 0;
472 
473 	/* If touchscreen is enable, then reserve the adc channels */
474 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
475 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
476 	else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
477 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
478 
479 	/* set up the channel mask to reserve touchscreen channels */
480 	st->channels_mask &= ~rsvd_mask;
481 
482 	idev->num_channels = bitmap_weight(&st->channels_mask,
483 					   st->num_channels) + 1;
484 
485 	chan_array = devm_kzalloc(&idev->dev,
486 				  ((idev->num_channels + 1) *
487 					sizeof(struct iio_chan_spec)),
488 				  GFP_KERNEL);
489 
490 	if (!chan_array)
491 		return -ENOMEM;
492 
493 	for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
494 		struct iio_chan_spec *chan = chan_array + idx;
495 
496 		chan->type = IIO_VOLTAGE;
497 		chan->indexed = 1;
498 		chan->channel = bit;
499 		chan->scan_index = idx;
500 		chan->scan_type.sign = 'u';
501 		chan->scan_type.realbits = st->res;
502 		chan->scan_type.storagebits = 16;
503 		chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
504 		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
505 		idx++;
506 	}
507 	timestamp = chan_array + idx;
508 
509 	timestamp->type = IIO_TIMESTAMP;
510 	timestamp->channel = -1;
511 	timestamp->scan_index = idx;
512 	timestamp->scan_type.sign = 's';
513 	timestamp->scan_type.realbits = 64;
514 	timestamp->scan_type.storagebits = 64;
515 
516 	idev->channels = chan_array;
517 	return idev->num_channels;
518 }
519 
520 static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
521 					     struct at91_adc_trigger *triggers,
522 					     const char *trigger_name)
523 {
524 	struct at91_adc_state *st = iio_priv(idev);
525 	int i;
526 
527 	for (i = 0; i < st->trigger_number; i++) {
528 		char *name = kasprintf(GFP_KERNEL,
529 				"%s-dev%d-%s",
530 				idev->name,
531 				idev->id,
532 				triggers[i].name);
533 		if (!name)
534 			return -ENOMEM;
535 
536 		if (strcmp(trigger_name, name) == 0) {
537 			kfree(name);
538 			if (triggers[i].value == 0)
539 				return -EINVAL;
540 			return triggers[i].value;
541 		}
542 
543 		kfree(name);
544 	}
545 
546 	return -EINVAL;
547 }
548 
549 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
550 {
551 	struct iio_dev *idev = iio_trigger_get_drvdata(trig);
552 	struct at91_adc_state *st = iio_priv(idev);
553 	struct at91_adc_reg_desc *reg = st->registers;
554 	u32 status = at91_adc_readl(st, reg->trigger_register);
555 	int value;
556 	u8 bit;
557 
558 	value = at91_adc_get_trigger_value_by_name(idev,
559 						   st->trigger_list,
560 						   idev->trig->name);
561 	if (value < 0)
562 		return value;
563 
564 	if (state) {
565 		st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
566 		if (st->buffer == NULL)
567 			return -ENOMEM;
568 
569 		at91_adc_writel(st, reg->trigger_register,
570 				status | value);
571 
572 		for_each_set_bit(bit, idev->active_scan_mask,
573 				 st->num_channels) {
574 			struct iio_chan_spec const *chan = idev->channels + bit;
575 			at91_adc_writel(st, AT91_ADC_CHER,
576 					AT91_ADC_CH(chan->channel));
577 		}
578 
579 		at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
580 
581 	} else {
582 		at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
583 
584 		at91_adc_writel(st, reg->trigger_register,
585 				status & ~value);
586 
587 		for_each_set_bit(bit, idev->active_scan_mask,
588 				 st->num_channels) {
589 			struct iio_chan_spec const *chan = idev->channels + bit;
590 			at91_adc_writel(st, AT91_ADC_CHDR,
591 					AT91_ADC_CH(chan->channel));
592 		}
593 		kfree(st->buffer);
594 	}
595 
596 	return 0;
597 }
598 
599 static const struct iio_trigger_ops at91_adc_trigger_ops = {
600 	.set_trigger_state = &at91_adc_configure_trigger,
601 };
602 
603 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
604 						     struct at91_adc_trigger *trigger)
605 {
606 	struct iio_trigger *trig;
607 	int ret;
608 
609 	trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
610 				 idev->id, trigger->name);
611 	if (trig == NULL)
612 		return NULL;
613 
614 	trig->dev.parent = idev->dev.parent;
615 	iio_trigger_set_drvdata(trig, idev);
616 	trig->ops = &at91_adc_trigger_ops;
617 
618 	ret = iio_trigger_register(trig);
619 	if (ret)
620 		return NULL;
621 
622 	return trig;
623 }
624 
625 static int at91_adc_trigger_init(struct iio_dev *idev)
626 {
627 	struct at91_adc_state *st = iio_priv(idev);
628 	int i, ret;
629 
630 	st->trig = devm_kcalloc(&idev->dev,
631 				st->trigger_number, sizeof(*st->trig),
632 				GFP_KERNEL);
633 
634 	if (st->trig == NULL) {
635 		ret = -ENOMEM;
636 		goto error_ret;
637 	}
638 
639 	for (i = 0; i < st->trigger_number; i++) {
640 		if (st->trigger_list[i].is_external && !(st->use_external))
641 			continue;
642 
643 		st->trig[i] = at91_adc_allocate_trigger(idev,
644 							st->trigger_list + i);
645 		if (st->trig[i] == NULL) {
646 			dev_err(&idev->dev,
647 				"Could not allocate trigger %d\n", i);
648 			ret = -ENOMEM;
649 			goto error_trigger;
650 		}
651 	}
652 
653 	return 0;
654 
655 error_trigger:
656 	for (i--; i >= 0; i--) {
657 		iio_trigger_unregister(st->trig[i]);
658 		iio_trigger_free(st->trig[i]);
659 	}
660 error_ret:
661 	return ret;
662 }
663 
664 static void at91_adc_trigger_remove(struct iio_dev *idev)
665 {
666 	struct at91_adc_state *st = iio_priv(idev);
667 	int i;
668 
669 	for (i = 0; i < st->trigger_number; i++) {
670 		iio_trigger_unregister(st->trig[i]);
671 		iio_trigger_free(st->trig[i]);
672 	}
673 }
674 
675 static int at91_adc_buffer_init(struct iio_dev *idev)
676 {
677 	return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
678 		&at91_adc_trigger_handler, NULL);
679 }
680 
681 static void at91_adc_buffer_remove(struct iio_dev *idev)
682 {
683 	iio_triggered_buffer_cleanup(idev);
684 }
685 
686 static int at91_adc_read_raw(struct iio_dev *idev,
687 			     struct iio_chan_spec const *chan,
688 			     int *val, int *val2, long mask)
689 {
690 	struct at91_adc_state *st = iio_priv(idev);
691 	int ret;
692 
693 	switch (mask) {
694 	case IIO_CHAN_INFO_RAW:
695 		mutex_lock(&st->lock);
696 
697 		st->chnb = chan->channel;
698 		at91_adc_writel(st, AT91_ADC_CHER,
699 				AT91_ADC_CH(chan->channel));
700 		at91_adc_writel(st, AT91_ADC_IER, BIT(chan->channel));
701 		at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
702 
703 		ret = wait_event_interruptible_timeout(st->wq_data_avail,
704 						       st->done,
705 						       msecs_to_jiffies(1000));
706 
707 		/* Disable interrupts, regardless if adc conversion was
708 		 * successful or not
709 		 */
710 		at91_adc_writel(st, AT91_ADC_CHDR,
711 				AT91_ADC_CH(chan->channel));
712 		at91_adc_writel(st, AT91_ADC_IDR, BIT(chan->channel));
713 
714 		if (ret > 0) {
715 			/* a valid conversion took place */
716 			*val = st->last_value;
717 			st->last_value = 0;
718 			st->done = false;
719 			ret = IIO_VAL_INT;
720 		} else if (ret == 0) {
721 			/* conversion timeout */
722 			dev_err(&idev->dev, "ADC Channel %d timeout.\n",
723 				chan->channel);
724 			ret = -ETIMEDOUT;
725 		}
726 
727 		mutex_unlock(&st->lock);
728 		return ret;
729 
730 	case IIO_CHAN_INFO_SCALE:
731 		*val = st->vref_mv;
732 		*val2 = chan->scan_type.realbits;
733 		return IIO_VAL_FRACTIONAL_LOG2;
734 	default:
735 		break;
736 	}
737 	return -EINVAL;
738 }
739 
740 static int at91_adc_of_get_resolution(struct at91_adc_state *st,
741 				      struct platform_device *pdev)
742 {
743 	struct iio_dev *idev = iio_priv_to_dev(st);
744 	struct device_node *np = pdev->dev.of_node;
745 	int count, i, ret = 0;
746 	char *res_name, *s;
747 	u32 *resolutions;
748 
749 	count = of_property_count_strings(np, "atmel,adc-res-names");
750 	if (count < 2) {
751 		dev_err(&idev->dev, "You must specified at least two resolution names for "
752 				    "adc-res-names property in the DT\n");
753 		return count;
754 	}
755 
756 	resolutions = kmalloc_array(count, sizeof(*resolutions), GFP_KERNEL);
757 	if (!resolutions)
758 		return -ENOMEM;
759 
760 	if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) {
761 		dev_err(&idev->dev, "Missing adc-res property in the DT.\n");
762 		ret = -ENODEV;
763 		goto ret;
764 	}
765 
766 	if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name))
767 		res_name = "highres";
768 
769 	for (i = 0; i < count; i++) {
770 		if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s))
771 			continue;
772 
773 		if (strcmp(res_name, s))
774 			continue;
775 
776 		st->res = resolutions[i];
777 		if (!strcmp(res_name, "lowres"))
778 			st->low_res = true;
779 		else
780 			st->low_res = false;
781 
782 		dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
783 		goto ret;
784 	}
785 
786 	dev_err(&idev->dev, "There is no resolution for %s\n", res_name);
787 
788 ret:
789 	kfree(resolutions);
790 	return ret;
791 }
792 
793 static u32 calc_startup_ticks_9260(u32 startup_time, u32 adc_clk_khz)
794 {
795 	/*
796 	 * Number of ticks needed to cover the startup time of the ADC
797 	 * as defined in the electrical characteristics of the board,
798 	 * divided by 8. The formula thus is :
799 	 *   Startup Time = (ticks + 1) * 8 / ADC Clock
800 	 */
801 	return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
802 }
803 
804 static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz)
805 {
806 	/*
807 	 * For sama5d3x and at91sam9x5, the formula changes to:
808 	 * Startup Time = <lookup_table_value> / ADC Clock
809 	 */
810 	static const int startup_lookup[] = {
811 		0,   8,   16,  24,
812 		64,  80,  96,  112,
813 		512, 576, 640, 704,
814 		768, 832, 896, 960
815 		};
816 	int i, size = ARRAY_SIZE(startup_lookup);
817 	unsigned int ticks;
818 
819 	ticks = startup_time * adc_clk_khz / 1000;
820 	for (i = 0; i < size; i++)
821 		if (ticks < startup_lookup[i])
822 			break;
823 
824 	ticks = i;
825 	if (ticks == size)
826 		/* Reach the end of lookup table */
827 		ticks = size - 1;
828 
829 	return ticks;
830 }
831 
832 static const struct of_device_id at91_adc_dt_ids[];
833 
834 static int at91_adc_probe_dt_ts(struct device_node *node,
835 	struct at91_adc_state *st, struct device *dev)
836 {
837 	int ret;
838 	u32 prop;
839 
840 	ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
841 	if (ret) {
842 		dev_info(dev, "ADC Touch screen is disabled.\n");
843 		return 0;
844 	}
845 
846 	switch (prop) {
847 	case 4:
848 	case 5:
849 		st->touchscreen_type = prop;
850 		break;
851 	default:
852 		dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
853 		return -EINVAL;
854 	}
855 
856 	if (!st->caps->has_tsmr)
857 		return 0;
858 	prop = 0;
859 	of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
860 	st->ts_pressure_threshold = prop;
861 	if (st->ts_pressure_threshold) {
862 		return 0;
863 	} else {
864 		dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
865 		return -EINVAL;
866 	}
867 }
868 
869 static int at91_adc_probe_dt(struct at91_adc_state *st,
870 			     struct platform_device *pdev)
871 {
872 	struct iio_dev *idev = iio_priv_to_dev(st);
873 	struct device_node *node = pdev->dev.of_node;
874 	struct device_node *trig_node;
875 	int i = 0, ret;
876 	u32 prop;
877 
878 	if (!node)
879 		return -EINVAL;
880 
881 	st->caps = (struct at91_adc_caps *)
882 		of_match_device(at91_adc_dt_ids, &pdev->dev)->data;
883 
884 	st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
885 
886 	if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
887 		dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
888 		ret = -EINVAL;
889 		goto error_ret;
890 	}
891 	st->channels_mask = prop;
892 
893 	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
894 
895 	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
896 		dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
897 		ret = -EINVAL;
898 		goto error_ret;
899 	}
900 	st->startup_time = prop;
901 
902 	prop = 0;
903 	of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
904 	st->sample_hold_time = prop;
905 
906 	if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
907 		dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
908 		ret = -EINVAL;
909 		goto error_ret;
910 	}
911 	st->vref_mv = prop;
912 
913 	ret = at91_adc_of_get_resolution(st, pdev);
914 	if (ret)
915 		goto error_ret;
916 
917 	st->registers = &st->caps->registers;
918 	st->num_channels = st->caps->num_channels;
919 	st->trigger_number = of_get_child_count(node);
920 	st->trigger_list = devm_kcalloc(&idev->dev,
921 					st->trigger_number,
922 					sizeof(struct at91_adc_trigger),
923 					GFP_KERNEL);
924 	if (!st->trigger_list) {
925 		dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
926 		ret = -ENOMEM;
927 		goto error_ret;
928 	}
929 
930 	for_each_child_of_node(node, trig_node) {
931 		struct at91_adc_trigger *trig = st->trigger_list + i;
932 		const char *name;
933 
934 		if (of_property_read_string(trig_node, "trigger-name", &name)) {
935 			dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
936 			ret = -EINVAL;
937 			goto error_ret;
938 		}
939 		trig->name = name;
940 
941 		if (of_property_read_u32(trig_node, "trigger-value", &prop)) {
942 			dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
943 			ret = -EINVAL;
944 			goto error_ret;
945 		}
946 		trig->value = prop;
947 		trig->is_external = of_property_read_bool(trig_node, "trigger-external");
948 		i++;
949 	}
950 
951 	/* Check if touchscreen is supported. */
952 	if (st->caps->has_ts)
953 		return at91_adc_probe_dt_ts(node, st, &idev->dev);
954 	else
955 		dev_info(&idev->dev, "not support touchscreen in the adc compatible string.\n");
956 
957 	return 0;
958 
959 error_ret:
960 	return ret;
961 }
962 
963 static int at91_adc_probe_pdata(struct at91_adc_state *st,
964 				struct platform_device *pdev)
965 {
966 	struct at91_adc_data *pdata = pdev->dev.platform_data;
967 
968 	if (!pdata)
969 		return -EINVAL;
970 
971 	st->caps = (struct at91_adc_caps *)
972 			platform_get_device_id(pdev)->driver_data;
973 
974 	st->use_external = pdata->use_external_triggers;
975 	st->vref_mv = pdata->vref;
976 	st->channels_mask = pdata->channels_used;
977 	st->num_channels = st->caps->num_channels;
978 	st->startup_time = pdata->startup_time;
979 	st->trigger_number = pdata->trigger_number;
980 	st->trigger_list = pdata->trigger_list;
981 	st->registers = &st->caps->registers;
982 	st->touchscreen_type = pdata->touchscreen_type;
983 
984 	return 0;
985 }
986 
987 static const struct iio_info at91_adc_info = {
988 	.read_raw = &at91_adc_read_raw,
989 };
990 
991 /* Touchscreen related functions */
992 static int atmel_ts_open(struct input_dev *dev)
993 {
994 	struct at91_adc_state *st = input_get_drvdata(dev);
995 
996 	if (st->caps->has_tsmr)
997 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
998 	else
999 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
1000 	return 0;
1001 }
1002 
1003 static void atmel_ts_close(struct input_dev *dev)
1004 {
1005 	struct at91_adc_state *st = input_get_drvdata(dev);
1006 
1007 	if (st->caps->has_tsmr)
1008 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
1009 	else
1010 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
1011 }
1012 
1013 static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
1014 {
1015 	struct iio_dev *idev = iio_priv_to_dev(st);
1016 	u32 reg = 0;
1017 	u32 tssctim = 0;
1018 	int i = 0;
1019 
1020 	/* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
1021 	 * pen detect noise.
1022 	 * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
1023 	 */
1024 	st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
1025 				 1000, 1);
1026 
1027 	while (st->ts_pendbc >> ++i)
1028 		;	/* Empty! Find the shift offset */
1029 	if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
1030 		st->ts_pendbc = i;
1031 	else
1032 		st->ts_pendbc = i - 1;
1033 
1034 	if (!st->caps->has_tsmr) {
1035 		reg = at91_adc_readl(st, AT91_ADC_MR);
1036 		reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
1037 
1038 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
1039 		at91_adc_writel(st, AT91_ADC_MR, reg);
1040 
1041 		reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
1042 		at91_adc_writel(st, AT91_ADC_TSR, reg);
1043 
1044 		st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
1045 						    adc_clk_khz / 1000) - 1, 1);
1046 
1047 		return 0;
1048 	}
1049 
1050 	/* Touchscreen Switches Closure time needed for allowing the value to
1051 	 * stabilize.
1052 	 * Switch Closure Time = (TSSCTIM * 4) ADCClock periods
1053 	 */
1054 	tssctim = DIV_ROUND_UP(TOUCH_SCTIM_US * adc_clk_khz / 1000, 4);
1055 	dev_dbg(&idev->dev, "adc_clk at: %d KHz, tssctim at: %d\n",
1056 		adc_clk_khz, tssctim);
1057 
1058 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
1059 		reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
1060 	else
1061 		reg = AT91_ADC_TSMR_TSMODE_5WIRE;
1062 
1063 	reg |= AT91_ADC_TSMR_SCTIM_(tssctim) & AT91_ADC_TSMR_SCTIM;
1064 	reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
1065 	       & AT91_ADC_TSMR_TSAV;
1066 	reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
1067 	reg |= AT91_ADC_TSMR_NOTSDMA;
1068 	reg |= AT91_ADC_TSMR_PENDET_ENA;
1069 	reg |= 0x03 << 8;	/* TSFREQ, needs to be bigger than TSAV */
1070 
1071 	at91_adc_writel(st, AT91_ADC_TSMR, reg);
1072 
1073 	/* Change adc internal resistor value for better pen detection,
1074 	 * default value is 100 kOhm.
1075 	 * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
1076 	 * option only available on ES2 and higher
1077 	 */
1078 	at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
1079 			& AT91_ADC_ACR_PENDETSENS);
1080 
1081 	/* Sample Period Time = (TRGPER + 1) / ADCClock */
1082 	st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
1083 			adc_clk_khz / 1000) - 1, 1);
1084 
1085 	return 0;
1086 }
1087 
1088 static int at91_ts_register(struct at91_adc_state *st,
1089 		struct platform_device *pdev)
1090 {
1091 	struct input_dev *input;
1092 	struct iio_dev *idev = iio_priv_to_dev(st);
1093 	int ret;
1094 
1095 	input = input_allocate_device();
1096 	if (!input) {
1097 		dev_err(&idev->dev, "Failed to allocate TS device!\n");
1098 		return -ENOMEM;
1099 	}
1100 
1101 	input->name = DRIVER_NAME;
1102 	input->id.bustype = BUS_HOST;
1103 	input->dev.parent = &pdev->dev;
1104 	input->open = atmel_ts_open;
1105 	input->close = atmel_ts_close;
1106 
1107 	__set_bit(EV_ABS, input->evbit);
1108 	__set_bit(EV_KEY, input->evbit);
1109 	__set_bit(BTN_TOUCH, input->keybit);
1110 	if (st->caps->has_tsmr) {
1111 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
1112 				     0, 0);
1113 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
1114 				     0, 0);
1115 		input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
1116 	} else {
1117 		if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
1118 			dev_err(&pdev->dev,
1119 				"This touchscreen controller only support 4 wires\n");
1120 			ret = -EINVAL;
1121 			goto err;
1122 		}
1123 
1124 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
1125 				     0, 0);
1126 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
1127 				     0, 0);
1128 	}
1129 
1130 	st->ts_input = input;
1131 	input_set_drvdata(input, st);
1132 
1133 	ret = input_register_device(input);
1134 	if (ret)
1135 		goto err;
1136 
1137 	return ret;
1138 
1139 err:
1140 	input_free_device(st->ts_input);
1141 	return ret;
1142 }
1143 
1144 static void at91_ts_unregister(struct at91_adc_state *st)
1145 {
1146 	input_unregister_device(st->ts_input);
1147 }
1148 
1149 static int at91_adc_probe(struct platform_device *pdev)
1150 {
1151 	unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
1152 	int ret;
1153 	struct iio_dev *idev;
1154 	struct at91_adc_state *st;
1155 	struct resource *res;
1156 	u32 reg;
1157 
1158 	idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
1159 	if (!idev)
1160 		return -ENOMEM;
1161 
1162 	st = iio_priv(idev);
1163 
1164 	if (pdev->dev.of_node)
1165 		ret = at91_adc_probe_dt(st, pdev);
1166 	else
1167 		ret = at91_adc_probe_pdata(st, pdev);
1168 
1169 	if (ret) {
1170 		dev_err(&pdev->dev, "No platform data available.\n");
1171 		return -EINVAL;
1172 	}
1173 
1174 	platform_set_drvdata(pdev, idev);
1175 
1176 	idev->dev.parent = &pdev->dev;
1177 	idev->name = dev_name(&pdev->dev);
1178 	idev->modes = INDIO_DIRECT_MODE;
1179 	idev->info = &at91_adc_info;
1180 
1181 	st->irq = platform_get_irq(pdev, 0);
1182 	if (st->irq < 0)
1183 		return -ENODEV;
1184 
1185 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1186 
1187 	st->reg_base = devm_ioremap_resource(&pdev->dev, res);
1188 	if (IS_ERR(st->reg_base))
1189 		return PTR_ERR(st->reg_base);
1190 
1191 
1192 	/*
1193 	 * Disable all IRQs before setting up the handler
1194 	 */
1195 	at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
1196 	at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
1197 
1198 	if (st->caps->has_tsmr)
1199 		ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0,
1200 				  pdev->dev.driver->name, idev);
1201 	else
1202 		ret = request_irq(st->irq, at91_adc_rl_interrupt, 0,
1203 				  pdev->dev.driver->name, idev);
1204 	if (ret) {
1205 		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
1206 		return ret;
1207 	}
1208 
1209 	st->clk = devm_clk_get(&pdev->dev, "adc_clk");
1210 	if (IS_ERR(st->clk)) {
1211 		dev_err(&pdev->dev, "Failed to get the clock.\n");
1212 		ret = PTR_ERR(st->clk);
1213 		goto error_free_irq;
1214 	}
1215 
1216 	ret = clk_prepare_enable(st->clk);
1217 	if (ret) {
1218 		dev_err(&pdev->dev,
1219 			"Could not prepare or enable the clock.\n");
1220 		goto error_free_irq;
1221 	}
1222 
1223 	st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
1224 	if (IS_ERR(st->adc_clk)) {
1225 		dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
1226 		ret = PTR_ERR(st->adc_clk);
1227 		goto error_disable_clk;
1228 	}
1229 
1230 	ret = clk_prepare_enable(st->adc_clk);
1231 	if (ret) {
1232 		dev_err(&pdev->dev,
1233 			"Could not prepare or enable the ADC clock.\n");
1234 		goto error_disable_clk;
1235 	}
1236 
1237 	/*
1238 	 * Prescaler rate computation using the formula from the Atmel's
1239 	 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
1240 	 * specified by the electrical characteristics of the board.
1241 	 */
1242 	mstrclk = clk_get_rate(st->clk);
1243 	adc_clk = clk_get_rate(st->adc_clk);
1244 	adc_clk_khz = adc_clk / 1000;
1245 
1246 	dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
1247 		mstrclk, adc_clk);
1248 
1249 	prsc = (mstrclk / (2 * adc_clk)) - 1;
1250 
1251 	if (!st->startup_time) {
1252 		dev_err(&pdev->dev, "No startup time available.\n");
1253 		ret = -EINVAL;
1254 		goto error_disable_adc_clk;
1255 	}
1256 	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
1257 
1258 	/*
1259 	 * a minimal Sample and Hold Time is necessary for the ADC to guarantee
1260 	 * the best converted final value between two channels selection
1261 	 * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
1262 	 */
1263 	if (st->sample_hold_time > 0)
1264 		shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000)
1265 				 - 1, 1);
1266 	else
1267 		shtim = 0;
1268 
1269 	reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
1270 	reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
1271 	if (st->low_res)
1272 		reg |= AT91_ADC_LOWRES;
1273 	if (st->sleep_mode)
1274 		reg |= AT91_ADC_SLEEP;
1275 	reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
1276 	at91_adc_writel(st, AT91_ADC_MR, reg);
1277 
1278 	/* Setup the ADC channels available on the board */
1279 	ret = at91_adc_channel_init(idev);
1280 	if (ret < 0) {
1281 		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
1282 		goto error_disable_adc_clk;
1283 	}
1284 
1285 	init_waitqueue_head(&st->wq_data_avail);
1286 	mutex_init(&st->lock);
1287 
1288 	/*
1289 	 * Since touch screen will set trigger register as period trigger. So
1290 	 * when touch screen is enabled, then we have to disable hardware
1291 	 * trigger for classic adc.
1292 	 */
1293 	if (!st->touchscreen_type) {
1294 		ret = at91_adc_buffer_init(idev);
1295 		if (ret < 0) {
1296 			dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
1297 			goto error_disable_adc_clk;
1298 		}
1299 
1300 		ret = at91_adc_trigger_init(idev);
1301 		if (ret < 0) {
1302 			dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
1303 			at91_adc_buffer_remove(idev);
1304 			goto error_disable_adc_clk;
1305 		}
1306 	} else {
1307 		ret = at91_ts_register(st, pdev);
1308 		if (ret)
1309 			goto error_disable_adc_clk;
1310 
1311 		at91_ts_hw_init(st, adc_clk_khz);
1312 	}
1313 
1314 	ret = iio_device_register(idev);
1315 	if (ret < 0) {
1316 		dev_err(&pdev->dev, "Couldn't register the device.\n");
1317 		goto error_iio_device_register;
1318 	}
1319 
1320 	return 0;
1321 
1322 error_iio_device_register:
1323 	if (!st->touchscreen_type) {
1324 		at91_adc_trigger_remove(idev);
1325 		at91_adc_buffer_remove(idev);
1326 	} else {
1327 		at91_ts_unregister(st);
1328 	}
1329 error_disable_adc_clk:
1330 	clk_disable_unprepare(st->adc_clk);
1331 error_disable_clk:
1332 	clk_disable_unprepare(st->clk);
1333 error_free_irq:
1334 	free_irq(st->irq, idev);
1335 	return ret;
1336 }
1337 
1338 static int at91_adc_remove(struct platform_device *pdev)
1339 {
1340 	struct iio_dev *idev = platform_get_drvdata(pdev);
1341 	struct at91_adc_state *st = iio_priv(idev);
1342 
1343 	iio_device_unregister(idev);
1344 	if (!st->touchscreen_type) {
1345 		at91_adc_trigger_remove(idev);
1346 		at91_adc_buffer_remove(idev);
1347 	} else {
1348 		at91_ts_unregister(st);
1349 	}
1350 	clk_disable_unprepare(st->adc_clk);
1351 	clk_disable_unprepare(st->clk);
1352 	free_irq(st->irq, idev);
1353 
1354 	return 0;
1355 }
1356 
1357 #ifdef CONFIG_PM_SLEEP
1358 static int at91_adc_suspend(struct device *dev)
1359 {
1360 	struct iio_dev *idev = dev_get_drvdata(dev);
1361 	struct at91_adc_state *st = iio_priv(idev);
1362 
1363 	pinctrl_pm_select_sleep_state(dev);
1364 	clk_disable_unprepare(st->clk);
1365 
1366 	return 0;
1367 }
1368 
1369 static int at91_adc_resume(struct device *dev)
1370 {
1371 	struct iio_dev *idev = dev_get_drvdata(dev);
1372 	struct at91_adc_state *st = iio_priv(idev);
1373 
1374 	clk_prepare_enable(st->clk);
1375 	pinctrl_pm_select_default_state(dev);
1376 
1377 	return 0;
1378 }
1379 #endif
1380 
1381 static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume);
1382 
1383 static struct at91_adc_caps at91sam9260_caps = {
1384 	.calc_startup_ticks = calc_startup_ticks_9260,
1385 	.num_channels = 4,
1386 	.registers = {
1387 		.channel_base = AT91_ADC_CHR(0),
1388 		.drdy_mask = AT91_ADC_DRDY,
1389 		.status_register = AT91_ADC_SR,
1390 		.trigger_register = AT91_ADC_TRGR_9260,
1391 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1392 		.mr_startup_mask = AT91_ADC_STARTUP_9260,
1393 	},
1394 };
1395 
1396 static struct at91_adc_caps at91sam9rl_caps = {
1397 	.has_ts = true,
1398 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1399 	.num_channels = 6,
1400 	.registers = {
1401 		.channel_base = AT91_ADC_CHR(0),
1402 		.drdy_mask = AT91_ADC_DRDY,
1403 		.status_register = AT91_ADC_SR,
1404 		.trigger_register = AT91_ADC_TRGR_9G45,
1405 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1406 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1407 	},
1408 };
1409 
1410 static struct at91_adc_caps at91sam9g45_caps = {
1411 	.has_ts = true,
1412 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1413 	.num_channels = 8,
1414 	.registers = {
1415 		.channel_base = AT91_ADC_CHR(0),
1416 		.drdy_mask = AT91_ADC_DRDY,
1417 		.status_register = AT91_ADC_SR,
1418 		.trigger_register = AT91_ADC_TRGR_9G45,
1419 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1420 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1421 	},
1422 };
1423 
1424 static struct at91_adc_caps at91sam9x5_caps = {
1425 	.has_ts = true,
1426 	.has_tsmr = true,
1427 	.ts_filter_average = 3,
1428 	.ts_pen_detect_sensitivity = 2,
1429 	.calc_startup_ticks = calc_startup_ticks_9x5,
1430 	.num_channels = 12,
1431 	.registers = {
1432 		.channel_base = AT91_ADC_CDR0_9X5,
1433 		.drdy_mask = AT91_ADC_SR_DRDY_9X5,
1434 		.status_register = AT91_ADC_SR_9X5,
1435 		.trigger_register = AT91_ADC_TRGR_9X5,
1436 		/* prescal mask is same as 9G45 */
1437 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1438 		.mr_startup_mask = AT91_ADC_STARTUP_9X5,
1439 	},
1440 };
1441 
1442 static const struct of_device_id at91_adc_dt_ids[] = {
1443 	{ .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
1444 	{ .compatible = "atmel,at91sam9rl-adc", .data = &at91sam9rl_caps },
1445 	{ .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
1446 	{ .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
1447 	{},
1448 };
1449 MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
1450 
1451 static const struct platform_device_id at91_adc_ids[] = {
1452 	{
1453 		.name = "at91sam9260-adc",
1454 		.driver_data = (unsigned long)&at91sam9260_caps,
1455 	}, {
1456 		.name = "at91sam9rl-adc",
1457 		.driver_data = (unsigned long)&at91sam9rl_caps,
1458 	}, {
1459 		.name = "at91sam9g45-adc",
1460 		.driver_data = (unsigned long)&at91sam9g45_caps,
1461 	}, {
1462 		.name = "at91sam9x5-adc",
1463 		.driver_data = (unsigned long)&at91sam9x5_caps,
1464 	}, {
1465 		/* terminator */
1466 	}
1467 };
1468 MODULE_DEVICE_TABLE(platform, at91_adc_ids);
1469 
1470 static struct platform_driver at91_adc_driver = {
1471 	.probe = at91_adc_probe,
1472 	.remove = at91_adc_remove,
1473 	.id_table = at91_adc_ids,
1474 	.driver = {
1475 		   .name = DRIVER_NAME,
1476 		   .of_match_table = of_match_ptr(at91_adc_dt_ids),
1477 		   .pm = &at91_adc_pm_ops,
1478 	},
1479 };
1480 
1481 module_platform_driver(at91_adc_driver);
1482 
1483 MODULE_LICENSE("GPL");
1484 MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
1485 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1486