xref: /linux/drivers/iio/adc/at91_adc.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for the ADC present in the Atmel AT91 evaluation boards.
4  *
5  * Copyright 2011 Free Electrons
6  */
7 
8 #include <linux/bitmap.h>
9 #include <linux/bitops.h>
10 #include <linux/cleanup.h>
11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/input.h>
15 #include <linux/interrupt.h>
16 #include <linux/jiffies.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/wait.h>
24 
25 #include <linux/iio/iio.h>
26 #include <linux/iio/buffer.h>
27 #include <linux/iio/trigger.h>
28 #include <linux/iio/trigger_consumer.h>
29 #include <linux/iio/triggered_buffer.h>
30 #include <linux/pinctrl/consumer.h>
31 
32 /* Registers */
33 #define AT91_ADC_CR		0x00		/* Control Register */
34 #define		AT91_ADC_SWRST		(1 << 0)	/* Software Reset */
35 #define		AT91_ADC_START		(1 << 1)	/* Start Conversion */
36 
37 #define AT91_ADC_MR		0x04		/* Mode Register */
38 #define		AT91_ADC_TSAMOD		(3 << 0)	/* ADC mode */
39 #define		AT91_ADC_TSAMOD_ADC_ONLY_MODE		(0 << 0)	/* ADC Mode */
40 #define		AT91_ADC_TSAMOD_TS_ONLY_MODE		(1 << 0)	/* Touch Screen Only Mode */
41 #define		AT91_ADC_TRGEN		(1 << 0)	/* Trigger Enable */
42 #define		AT91_ADC_TRGSEL		(7 << 1)	/* Trigger Selection */
43 #define			AT91_ADC_TRGSEL_TC0		(0 << 1)
44 #define			AT91_ADC_TRGSEL_TC1		(1 << 1)
45 #define			AT91_ADC_TRGSEL_TC2		(2 << 1)
46 #define			AT91_ADC_TRGSEL_EXTERNAL	(6 << 1)
47 #define		AT91_ADC_LOWRES		(1 << 4)	/* Low Resolution */
48 #define		AT91_ADC_SLEEP		(1 << 5)	/* Sleep Mode */
49 #define		AT91_ADC_PENDET		(1 << 6)	/* Pen contact detection enable */
50 #define		AT91_ADC_PRESCAL_9260	(0x3f << 8)	/* Prescalar Rate Selection */
51 #define		AT91_ADC_PRESCAL_9G45	(0xff << 8)
52 #define			AT91_ADC_PRESCAL_(x)	((x) << 8)
53 #define		AT91_ADC_STARTUP_9260	(0x1f << 16)	/* Startup Up Time */
54 #define		AT91_ADC_STARTUP_9G45	(0x7f << 16)
55 #define		AT91_ADC_STARTUP_9X5	(0xf << 16)
56 #define			AT91_ADC_STARTUP_(x)	((x) << 16)
57 #define		AT91_ADC_SHTIM		(0xf  << 24)	/* Sample & Hold Time */
58 #define			AT91_ADC_SHTIM_(x)	((x) << 24)
59 #define		AT91_ADC_PENDBC		(0x0f << 28)	/* Pen Debounce time */
60 #define			AT91_ADC_PENDBC_(x)	((x) << 28)
61 
62 #define AT91_ADC_TSR		0x0C
63 #define		AT91_ADC_TSR_SHTIM	(0xf  << 24)	/* Sample & Hold Time */
64 #define			AT91_ADC_TSR_SHTIM_(x)	((x) << 24)
65 
66 #define AT91_ADC_CHER		0x10		/* Channel Enable Register */
67 #define AT91_ADC_CHDR		0x14		/* Channel Disable Register */
68 #define AT91_ADC_CHSR		0x18		/* Channel Status Register */
69 #define		AT91_ADC_CH(n)		(1 << (n))	/* Channel Number */
70 
71 #define AT91_ADC_SR		0x1C		/* Status Register */
72 #define		AT91_ADC_EOC(n)		(1 << (n))	/* End of Conversion on Channel N */
73 #define		AT91_ADC_OVRE(n)	(1 << ((n) + 8))/* Overrun Error on Channel N */
74 #define		AT91_ADC_DRDY		(1 << 16)	/* Data Ready */
75 #define		AT91_ADC_GOVRE		(1 << 17)	/* General Overrun Error */
76 #define		AT91_ADC_ENDRX		(1 << 18)	/* End of RX Buffer */
77 #define		AT91_ADC_RXFUFF		(1 << 19)	/* RX Buffer Full */
78 
79 #define AT91_ADC_SR_9X5		0x30		/* Status Register for 9x5 */
80 #define		AT91_ADC_SR_DRDY_9X5	(1 << 24)	/* Data Ready */
81 
82 #define AT91_ADC_LCDR		0x20		/* Last Converted Data Register */
83 #define		AT91_ADC_LDATA		(0x3ff)
84 
85 #define AT91_ADC_IER		0x24		/* Interrupt Enable Register */
86 #define AT91_ADC_IDR		0x28		/* Interrupt Disable Register */
87 #define AT91_ADC_IMR		0x2C		/* Interrupt Mask Register */
88 #define		AT91RL_ADC_IER_PEN	(1 << 20)
89 #define		AT91RL_ADC_IER_NOPEN	(1 << 21)
90 #define		AT91_ADC_IER_PEN	(1 << 29)
91 #define		AT91_ADC_IER_NOPEN	(1 << 30)
92 #define		AT91_ADC_IER_XRDY	(1 << 20)
93 #define		AT91_ADC_IER_YRDY	(1 << 21)
94 #define		AT91_ADC_IER_PRDY	(1 << 22)
95 #define		AT91_ADC_ISR_PENS	(1 << 31)
96 
97 #define AT91_ADC_CHR(n)		(0x30 + ((n) * 4))	/* Channel Data Register N */
98 #define		AT91_ADC_DATA		(0x3ff)
99 
100 #define AT91_ADC_CDR0_9X5	(0x50)			/* Channel Data Register 0 for 9X5 */
101 
102 #define AT91_ADC_ACR		0x94	/* Analog Control Register */
103 #define		AT91_ADC_ACR_PENDETSENS	(0x3 << 0)	/* pull-up resistor */
104 
105 #define AT91_ADC_TSMR		0xB0
106 #define		AT91_ADC_TSMR_TSMODE	(3 << 0)	/* Touch Screen Mode */
107 #define			AT91_ADC_TSMR_TSMODE_NONE		(0 << 0)
108 #define			AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS	(1 << 0)
109 #define			AT91_ADC_TSMR_TSMODE_4WIRE_PRESS	(2 << 0)
110 #define			AT91_ADC_TSMR_TSMODE_5WIRE		(3 << 0)
111 #define		AT91_ADC_TSMR_TSAV	(3 << 4)	/* Averages samples */
112 #define			AT91_ADC_TSMR_TSAV_(x)		((x) << 4)
113 #define		AT91_ADC_TSMR_SCTIM	(0x0f << 16)	/* Switch closure time */
114 #define			AT91_ADC_TSMR_SCTIM_(x)		((x) << 16)
115 #define		AT91_ADC_TSMR_PENDBC	(0x0f << 28)	/* Pen Debounce time */
116 #define			AT91_ADC_TSMR_PENDBC_(x)	((x) << 28)
117 #define		AT91_ADC_TSMR_NOTSDMA	(1 << 22)	/* No Touchscreen DMA */
118 #define		AT91_ADC_TSMR_PENDET_DIS	(0 << 24)	/* Pen contact detection disable */
119 #define		AT91_ADC_TSMR_PENDET_ENA	(1 << 24)	/* Pen contact detection enable */
120 
121 #define AT91_ADC_TSXPOSR	0xB4
122 #define AT91_ADC_TSYPOSR	0xB8
123 #define AT91_ADC_TSPRESSR	0xBC
124 
125 #define AT91_ADC_TRGR_9260	AT91_ADC_MR
126 #define AT91_ADC_TRGR_9G45	0x08
127 #define AT91_ADC_TRGR_9X5	0xC0
128 
129 /* Trigger Register bit field */
130 #define		AT91_ADC_TRGR_TRGPER	(0xffff << 16)
131 #define			AT91_ADC_TRGR_TRGPER_(x)	((x) << 16)
132 #define		AT91_ADC_TRGR_TRGMOD	(0x7 << 0)
133 #define			AT91_ADC_TRGR_NONE		(0 << 0)
134 #define			AT91_ADC_TRGR_MOD_PERIOD_TRIG	(5 << 0)
135 
136 #define AT91_ADC_CHAN(st, ch) \
137 	(st->registers->channel_base + (ch * 4))
138 #define at91_adc_readl(st, reg) \
139 	(readl_relaxed(st->reg_base + reg))
140 #define at91_adc_writel(st, reg, val) \
141 	(writel_relaxed(val, st->reg_base + reg))
142 
143 #define DRIVER_NAME		"at91_adc"
144 #define MAX_POS_BITS		12
145 
146 #define TOUCH_SAMPLE_PERIOD_US		2000	/* 2ms */
147 #define TOUCH_PEN_DETECT_DEBOUNCE_US	200
148 
149 #define MAX_RLPOS_BITS         10
150 #define TOUCH_SAMPLE_PERIOD_US_RL      10000   /* 10ms, the SoC can't keep up with 2ms */
151 #define TOUCH_SHTIM                    0xa
152 #define TOUCH_SCTIM_US		10		/* 10us for the Touchscreen Switches Closure Time */
153 
154 enum atmel_adc_ts_type {
155 	ATMEL_ADC_TOUCHSCREEN_NONE = 0,
156 	ATMEL_ADC_TOUCHSCREEN_4WIRE = 4,
157 	ATMEL_ADC_TOUCHSCREEN_5WIRE = 5,
158 };
159 
160 /**
161  * struct at91_adc_trigger - description of triggers
162  * @name:		name of the trigger advertised to the user
163  * @value:		value to set in the ADC's trigger setup register
164  *			to enable the trigger
165  * @is_external:	Does the trigger rely on an external pin?
166  */
167 struct at91_adc_trigger {
168 	const char	*name;
169 	u8		value;
170 	bool		is_external;
171 };
172 
173 /**
174  * struct at91_adc_reg_desc - Various informations relative to registers
175  * @channel_base:	Base offset for the channel data registers
176  * @drdy_mask:		Mask of the DRDY field in the relevant registers
177  *			(Interruptions registers mostly)
178  * @status_register:	Offset of the Interrupt Status Register
179  * @trigger_register:	Offset of the Trigger setup register
180  * @mr_prescal_mask:	Mask of the PRESCAL field in the adc MR register
181  * @mr_startup_mask:	Mask of the STARTUP field in the adc MR register
182  */
183 struct at91_adc_reg_desc {
184 	u8	channel_base;
185 	u32	drdy_mask;
186 	u8	status_register;
187 	u8	trigger_register;
188 	u32	mr_prescal_mask;
189 	u32	mr_startup_mask;
190 };
191 
192 struct at91_adc_caps {
193 	bool	has_ts;		/* Support touch screen */
194 	bool	has_tsmr;	/* only at91sam9x5, sama5d3 have TSMR reg */
195 	/*
196 	 * Numbers of sampling data will be averaged. Can be 0~3.
197 	 * Hardware can average (2 ^ ts_filter_average) sample data.
198 	 */
199 	u8	ts_filter_average;
200 	/* Pen Detection input pull-up resistor, can be 0~3 */
201 	u8	ts_pen_detect_sensitivity;
202 
203 	/* startup time calculate function */
204 	u32 (*calc_startup_ticks)(u32 startup_time, u32 adc_clk_khz);
205 
206 	u8	num_channels;
207 
208 	u8	low_res_bits;
209 	u8	high_res_bits;
210 	u32	trigger_number;
211 	const struct at91_adc_trigger *triggers;
212 	struct at91_adc_reg_desc registers;
213 };
214 
215 struct at91_adc_state {
216 	struct clk		*adc_clk;
217 	u16			*buffer;
218 	unsigned long		channels_mask;
219 	struct clk		*clk;
220 	bool			done;
221 	int			irq;
222 	u16			last_value;
223 	int			chnb;
224 	struct mutex		lock;
225 	u8			num_channels;
226 	void __iomem		*reg_base;
227 	const struct at91_adc_reg_desc *registers;
228 	u32			startup_time;
229 	u8			sample_hold_time;
230 	bool			sleep_mode;
231 	struct iio_trigger	**trig;
232 	bool			use_external;
233 	u32			vref_mv;
234 	u32			res;		/* resolution used for convertions */
235 	wait_queue_head_t	wq_data_avail;
236 	const struct at91_adc_caps	*caps;
237 
238 	/*
239 	 * Following ADC channels are shared by touchscreen:
240 	 *
241 	 * CH0 -- Touch screen XP/UL
242 	 * CH1 -- Touch screen XM/UR
243 	 * CH2 -- Touch screen YP/LL
244 	 * CH3 -- Touch screen YM/Sense
245 	 * CH4 -- Touch screen LR(5-wire only)
246 	 *
247 	 * The bitfields below represents the reserved channel in the
248 	 * touchscreen mode.
249 	 */
250 #define CHAN_MASK_TOUCHSCREEN_4WIRE	(0xf << 0)
251 #define CHAN_MASK_TOUCHSCREEN_5WIRE	(0x1f << 0)
252 	enum atmel_adc_ts_type	touchscreen_type;
253 	struct input_dev	*ts_input;
254 
255 	u16			ts_sample_period_val;
256 	u32			ts_pressure_threshold;
257 	u16			ts_pendbc;
258 
259 	bool			ts_bufferedmeasure;
260 	u32			ts_prev_absx;
261 	u32			ts_prev_absy;
262 };
263 
264 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
265 {
266 	struct iio_poll_func *pf = p;
267 	struct iio_dev *idev = pf->indio_dev;
268 	struct at91_adc_state *st = iio_priv(idev);
269 	struct iio_chan_spec const *chan;
270 	int i, j = 0;
271 
272 	iio_for_each_active_channel(idev, i) {
273 		chan = idev->channels + i;
274 		st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, chan->channel));
275 		j++;
276 	}
277 
278 	iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
279 
280 	iio_trigger_notify_done(idev->trig);
281 
282 	/* Needed to ACK the DRDY interruption */
283 	at91_adc_readl(st, AT91_ADC_LCDR);
284 
285 	enable_irq(st->irq);
286 
287 	return IRQ_HANDLED;
288 }
289 
290 /* Handler for classic adc channel eoc trigger */
291 static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
292 {
293 	struct at91_adc_state *st = iio_priv(idev);
294 
295 	if (iio_buffer_enabled(idev)) {
296 		disable_irq_nosync(irq);
297 		iio_trigger_poll(idev->trig);
298 	} else {
299 		st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
300 		/* Needed to ACK the DRDY interruption */
301 		at91_adc_readl(st, AT91_ADC_LCDR);
302 		st->done = true;
303 		wake_up_interruptible(&st->wq_data_avail);
304 	}
305 }
306 
307 static int at91_ts_sample(struct iio_dev *idev)
308 {
309 	struct at91_adc_state *st = iio_priv(idev);
310 	unsigned int xscale, yscale, reg, z1, z2;
311 	unsigned int x, y, pres, xpos, ypos;
312 	unsigned int rxp = 1;
313 	unsigned int factor = 1000;
314 
315 	unsigned int xyz_mask_bits = st->res;
316 	unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
317 
318 	/* calculate position */
319 	/* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
320 	reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
321 	xpos = reg & xyz_mask;
322 	x = (xpos << MAX_POS_BITS) - xpos;
323 	xscale = (reg >> 16) & xyz_mask;
324 	if (xscale == 0) {
325 		dev_err(&idev->dev, "Error: xscale == 0!\n");
326 		return -1;
327 	}
328 	x /= xscale;
329 
330 	/* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
331 	reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
332 	ypos = reg & xyz_mask;
333 	y = (ypos << MAX_POS_BITS) - ypos;
334 	yscale = (reg >> 16) & xyz_mask;
335 	if (yscale == 0) {
336 		dev_err(&idev->dev, "Error: yscale == 0!\n");
337 		return -1;
338 	}
339 	y /= yscale;
340 
341 	/* calculate the pressure */
342 	reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
343 	z1 = reg & xyz_mask;
344 	z2 = (reg >> 16) & xyz_mask;
345 
346 	if (z1 != 0)
347 		pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
348 			/ factor;
349 	else
350 		pres = st->ts_pressure_threshold;	/* no pen contacted */
351 
352 	dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
353 				xpos, xscale, ypos, yscale, z1, z2, pres);
354 
355 	if (pres < st->ts_pressure_threshold) {
356 		dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
357 					x, y, pres / factor);
358 		input_report_abs(st->ts_input, ABS_X, x);
359 		input_report_abs(st->ts_input, ABS_Y, y);
360 		input_report_abs(st->ts_input, ABS_PRESSURE, pres);
361 		input_report_key(st->ts_input, BTN_TOUCH, 1);
362 		input_sync(st->ts_input);
363 	} else {
364 		dev_dbg(&idev->dev, "pressure too low: not reporting\n");
365 	}
366 
367 	return 0;
368 }
369 
370 static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
371 {
372 	struct iio_dev *idev = private;
373 	struct at91_adc_state *st = iio_priv(idev);
374 	u32 status = at91_adc_readl(st, st->registers->status_register);
375 	unsigned int reg;
376 
377 	status &= at91_adc_readl(st, AT91_ADC_IMR);
378 	if (status & GENMASK(st->num_channels - 1, 0))
379 		handle_adc_eoc_trigger(irq, idev);
380 
381 	if (status & AT91RL_ADC_IER_PEN) {
382 		/* Disabling pen debounce is required to get a NOPEN irq */
383 		reg = at91_adc_readl(st, AT91_ADC_MR);
384 		reg &= ~AT91_ADC_PENDBC;
385 		at91_adc_writel(st, AT91_ADC_MR, reg);
386 
387 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
388 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
389 				| AT91_ADC_EOC(3));
390 		/* Set up period trigger for sampling */
391 		at91_adc_writel(st, st->registers->trigger_register,
392 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
393 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
394 	} else if (status & AT91RL_ADC_IER_NOPEN) {
395 		reg = at91_adc_readl(st, AT91_ADC_MR);
396 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
397 		at91_adc_writel(st, AT91_ADC_MR, reg);
398 		at91_adc_writel(st, st->registers->trigger_register,
399 			AT91_ADC_TRGR_NONE);
400 
401 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
402 				| AT91_ADC_EOC(3));
403 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
404 		st->ts_bufferedmeasure = false;
405 		input_report_key(st->ts_input, BTN_TOUCH, 0);
406 		input_sync(st->ts_input);
407 	} else if (status & AT91_ADC_EOC(3) && st->ts_input) {
408 		/* Conversion finished and we've a touchscreen */
409 		if (st->ts_bufferedmeasure) {
410 			/*
411 			 * Last measurement is always discarded, since it can
412 			 * be erroneous.
413 			 * Always report previous measurement
414 			 */
415 			input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
416 			input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
417 			input_report_key(st->ts_input, BTN_TOUCH, 1);
418 			input_sync(st->ts_input);
419 		} else
420 			st->ts_bufferedmeasure = true;
421 
422 		/* Now make new measurement */
423 		st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
424 				   << MAX_RLPOS_BITS;
425 		st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
426 
427 		st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
428 				   << MAX_RLPOS_BITS;
429 		st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
430 	}
431 
432 	return IRQ_HANDLED;
433 }
434 
435 static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
436 {
437 	struct iio_dev *idev = private;
438 	struct at91_adc_state *st = iio_priv(idev);
439 	u32 status = at91_adc_readl(st, st->registers->status_register);
440 	const uint32_t ts_data_irq_mask =
441 		AT91_ADC_IER_XRDY |
442 		AT91_ADC_IER_YRDY |
443 		AT91_ADC_IER_PRDY;
444 
445 	if (status & GENMASK(st->num_channels - 1, 0))
446 		handle_adc_eoc_trigger(irq, idev);
447 
448 	if (status & AT91_ADC_IER_PEN) {
449 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
450 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
451 			ts_data_irq_mask);
452 		/* Set up period trigger for sampling */
453 		at91_adc_writel(st, st->registers->trigger_register,
454 			AT91_ADC_TRGR_MOD_PERIOD_TRIG |
455 			AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
456 	} else if (status & AT91_ADC_IER_NOPEN) {
457 		at91_adc_writel(st, st->registers->trigger_register, 0);
458 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
459 			ts_data_irq_mask);
460 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
461 
462 		input_report_key(st->ts_input, BTN_TOUCH, 0);
463 		input_sync(st->ts_input);
464 	} else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
465 		/* Now all touchscreen data is ready */
466 
467 		if (status & AT91_ADC_ISR_PENS) {
468 			/* validate data by pen contact */
469 			at91_ts_sample(idev);
470 		} else {
471 			/* triggered by event that is no pen contact, just read
472 			 * them to clean the interrupt and discard all.
473 			 */
474 			at91_adc_readl(st, AT91_ADC_TSXPOSR);
475 			at91_adc_readl(st, AT91_ADC_TSYPOSR);
476 			at91_adc_readl(st, AT91_ADC_TSPRESSR);
477 		}
478 	}
479 
480 	return IRQ_HANDLED;
481 }
482 
483 static int at91_adc_channel_init(struct iio_dev *idev)
484 {
485 	struct at91_adc_state *st = iio_priv(idev);
486 	struct iio_chan_spec *chan_array, *timestamp;
487 	int bit, idx = 0;
488 	unsigned long rsvd_mask = 0;
489 
490 	/* If touchscreen is enable, then reserve the adc channels */
491 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
492 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
493 	else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
494 		rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
495 
496 	/* set up the channel mask to reserve touchscreen channels */
497 	st->channels_mask &= ~rsvd_mask;
498 
499 	idev->num_channels = bitmap_weight(&st->channels_mask,
500 					   st->num_channels) + 1;
501 
502 	chan_array = devm_kzalloc(&idev->dev,
503 				  ((idev->num_channels + 1) *
504 					sizeof(struct iio_chan_spec)),
505 				  GFP_KERNEL);
506 
507 	if (!chan_array)
508 		return -ENOMEM;
509 
510 	for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
511 		struct iio_chan_spec *chan = chan_array + idx;
512 
513 		chan->type = IIO_VOLTAGE;
514 		chan->indexed = 1;
515 		chan->channel = bit;
516 		chan->scan_index = idx;
517 		chan->scan_type.sign = 'u';
518 		chan->scan_type.realbits = st->res;
519 		chan->scan_type.storagebits = 16;
520 		chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
521 		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
522 		idx++;
523 	}
524 	timestamp = chan_array + idx;
525 
526 	timestamp->type = IIO_TIMESTAMP;
527 	timestamp->channel = -1;
528 	timestamp->scan_index = idx;
529 	timestamp->scan_type.sign = 's';
530 	timestamp->scan_type.realbits = 64;
531 	timestamp->scan_type.storagebits = 64;
532 
533 	idev->channels = chan_array;
534 	return idev->num_channels;
535 }
536 
537 static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
538 					     const struct at91_adc_trigger *triggers,
539 					     const char *trigger_name)
540 {
541 	struct at91_adc_state *st = iio_priv(idev);
542 	int i;
543 
544 	for (i = 0; i < st->caps->trigger_number; i++) {
545 		char *name __free(kfree) = kasprintf(GFP_KERNEL, "%s-dev%d-%s",
546 						     idev->name,
547 						     iio_device_id(idev),
548 						     triggers[i].name);
549 		if (!name)
550 			return -ENOMEM;
551 
552 		if (strcmp(trigger_name, name) == 0) {
553 			if (triggers[i].value == 0)
554 				return -EINVAL;
555 			return triggers[i].value;
556 		}
557 	}
558 
559 	return -EINVAL;
560 }
561 
562 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
563 {
564 	struct iio_dev *idev = iio_trigger_get_drvdata(trig);
565 	struct at91_adc_state *st = iio_priv(idev);
566 	const struct at91_adc_reg_desc *reg = st->registers;
567 	u32 status = at91_adc_readl(st, reg->trigger_register);
568 	int value;
569 	u8 bit;
570 
571 	value = at91_adc_get_trigger_value_by_name(idev,
572 						   st->caps->triggers,
573 						   idev->trig->name);
574 	if (value < 0)
575 		return value;
576 
577 	if (state) {
578 		st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
579 		if (st->buffer == NULL)
580 			return -ENOMEM;
581 
582 		at91_adc_writel(st, reg->trigger_register,
583 				status | value);
584 
585 		for_each_set_bit(bit, idev->active_scan_mask,
586 				 st->num_channels) {
587 			struct iio_chan_spec const *chan = idev->channels + bit;
588 			at91_adc_writel(st, AT91_ADC_CHER,
589 					AT91_ADC_CH(chan->channel));
590 		}
591 
592 		at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
593 
594 	} else {
595 		at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
596 
597 		at91_adc_writel(st, reg->trigger_register,
598 				status & ~value);
599 
600 		for_each_set_bit(bit, idev->active_scan_mask,
601 				 st->num_channels) {
602 			struct iio_chan_spec const *chan = idev->channels + bit;
603 			at91_adc_writel(st, AT91_ADC_CHDR,
604 					AT91_ADC_CH(chan->channel));
605 		}
606 		kfree(st->buffer);
607 	}
608 
609 	return 0;
610 }
611 
612 static const struct iio_trigger_ops at91_adc_trigger_ops = {
613 	.set_trigger_state = &at91_adc_configure_trigger,
614 };
615 
616 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
617 						     const struct at91_adc_trigger *trigger)
618 {
619 	struct iio_trigger *trig;
620 	int ret;
621 
622 	trig = iio_trigger_alloc(idev->dev.parent, "%s-dev%d-%s", idev->name,
623 				 iio_device_id(idev), trigger->name);
624 	if (trig == NULL)
625 		return NULL;
626 
627 	iio_trigger_set_drvdata(trig, idev);
628 	trig->ops = &at91_adc_trigger_ops;
629 
630 	ret = iio_trigger_register(trig);
631 	if (ret) {
632 		iio_trigger_free(trig);
633 		return NULL;
634 	}
635 
636 	return trig;
637 }
638 
639 static int at91_adc_trigger_init(struct iio_dev *idev)
640 {
641 	struct at91_adc_state *st = iio_priv(idev);
642 	int i, ret;
643 
644 	st->trig = devm_kcalloc(&idev->dev,
645 				st->caps->trigger_number, sizeof(*st->trig),
646 				GFP_KERNEL);
647 
648 	if (st->trig == NULL) {
649 		ret = -ENOMEM;
650 		goto error_ret;
651 	}
652 
653 	for (i = 0; i < st->caps->trigger_number; i++) {
654 		if (st->caps->triggers[i].is_external && !(st->use_external))
655 			continue;
656 
657 		st->trig[i] = at91_adc_allocate_trigger(idev,
658 							st->caps->triggers + i);
659 		if (st->trig[i] == NULL) {
660 			dev_err(&idev->dev,
661 				"Could not allocate trigger %d\n", i);
662 			ret = -ENOMEM;
663 			goto error_trigger;
664 		}
665 	}
666 
667 	return 0;
668 
669 error_trigger:
670 	for (i--; i >= 0; i--) {
671 		iio_trigger_unregister(st->trig[i]);
672 		iio_trigger_free(st->trig[i]);
673 	}
674 error_ret:
675 	return ret;
676 }
677 
678 static void at91_adc_trigger_remove(struct iio_dev *idev)
679 {
680 	struct at91_adc_state *st = iio_priv(idev);
681 	int i;
682 
683 	for (i = 0; i < st->caps->trigger_number; i++) {
684 		iio_trigger_unregister(st->trig[i]);
685 		iio_trigger_free(st->trig[i]);
686 	}
687 }
688 
689 static int at91_adc_buffer_init(struct iio_dev *idev)
690 {
691 	return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
692 		&at91_adc_trigger_handler, NULL);
693 }
694 
695 static void at91_adc_buffer_remove(struct iio_dev *idev)
696 {
697 	iio_triggered_buffer_cleanup(idev);
698 }
699 
700 static int at91_adc_read_raw(struct iio_dev *idev,
701 			     struct iio_chan_spec const *chan,
702 			     int *val, int *val2, long mask)
703 {
704 	struct at91_adc_state *st = iio_priv(idev);
705 	int ret;
706 
707 	switch (mask) {
708 	case IIO_CHAN_INFO_RAW:
709 		mutex_lock(&st->lock);
710 
711 		st->chnb = chan->channel;
712 		at91_adc_writel(st, AT91_ADC_CHER,
713 				AT91_ADC_CH(chan->channel));
714 		at91_adc_writel(st, AT91_ADC_IER, BIT(chan->channel));
715 		at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
716 
717 		ret = wait_event_interruptible_timeout(st->wq_data_avail,
718 						       st->done,
719 						       msecs_to_jiffies(1000));
720 
721 		/* Disable interrupts, regardless if adc conversion was
722 		 * successful or not
723 		 */
724 		at91_adc_writel(st, AT91_ADC_CHDR,
725 				AT91_ADC_CH(chan->channel));
726 		at91_adc_writel(st, AT91_ADC_IDR, BIT(chan->channel));
727 
728 		if (ret > 0) {
729 			/* a valid conversion took place */
730 			*val = st->last_value;
731 			st->last_value = 0;
732 			st->done = false;
733 			ret = IIO_VAL_INT;
734 		} else if (ret == 0) {
735 			/* conversion timeout */
736 			dev_err(&idev->dev, "ADC Channel %d timeout.\n",
737 				chan->channel);
738 			ret = -ETIMEDOUT;
739 		}
740 
741 		mutex_unlock(&st->lock);
742 		return ret;
743 
744 	case IIO_CHAN_INFO_SCALE:
745 		*val = st->vref_mv;
746 		*val2 = chan->scan_type.realbits;
747 		return IIO_VAL_FRACTIONAL_LOG2;
748 	default:
749 		break;
750 	}
751 	return -EINVAL;
752 }
753 
754 
755 static u32 calc_startup_ticks_9260(u32 startup_time, u32 adc_clk_khz)
756 {
757 	/*
758 	 * Number of ticks needed to cover the startup time of the ADC
759 	 * as defined in the electrical characteristics of the board,
760 	 * divided by 8. The formula thus is :
761 	 *   Startup Time = (ticks + 1) * 8 / ADC Clock
762 	 */
763 	return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
764 }
765 
766 static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz)
767 {
768 	/*
769 	 * For sama5d3x and at91sam9x5, the formula changes to:
770 	 * Startup Time = <lookup_table_value> / ADC Clock
771 	 */
772 	static const int startup_lookup[] = {
773 		0,   8,   16,  24,
774 		64,  80,  96,  112,
775 		512, 576, 640, 704,
776 		768, 832, 896, 960
777 		};
778 	int i, size = ARRAY_SIZE(startup_lookup);
779 	unsigned int ticks;
780 
781 	ticks = startup_time * adc_clk_khz / 1000;
782 	for (i = 0; i < size; i++)
783 		if (ticks < startup_lookup[i])
784 			break;
785 
786 	ticks = i;
787 	if (ticks == size)
788 		/* Reach the end of lookup table */
789 		ticks = size - 1;
790 
791 	return ticks;
792 }
793 
794 static int at91_adc_probe_dt_ts(struct device_node *node,
795 	struct at91_adc_state *st, struct device *dev)
796 {
797 	int ret;
798 	u32 prop;
799 
800 	ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
801 	if (ret) {
802 		dev_info(dev, "ADC Touch screen is disabled.\n");
803 		return 0;
804 	}
805 
806 	switch (prop) {
807 	case 4:
808 	case 5:
809 		st->touchscreen_type = prop;
810 		break;
811 	default:
812 		dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
813 		return -EINVAL;
814 	}
815 
816 	if (!st->caps->has_tsmr)
817 		return 0;
818 	prop = 0;
819 	of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
820 	st->ts_pressure_threshold = prop;
821 	if (st->ts_pressure_threshold) {
822 		return 0;
823 	} else {
824 		dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
825 		return -EINVAL;
826 	}
827 }
828 
829 static const struct iio_info at91_adc_info = {
830 	.read_raw = &at91_adc_read_raw,
831 };
832 
833 /* Touchscreen related functions */
834 static int atmel_ts_open(struct input_dev *dev)
835 {
836 	struct at91_adc_state *st = input_get_drvdata(dev);
837 
838 	if (st->caps->has_tsmr)
839 		at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
840 	else
841 		at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
842 	return 0;
843 }
844 
845 static void atmel_ts_close(struct input_dev *dev)
846 {
847 	struct at91_adc_state *st = input_get_drvdata(dev);
848 
849 	if (st->caps->has_tsmr)
850 		at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
851 	else
852 		at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
853 }
854 
855 static int at91_ts_hw_init(struct iio_dev *idev, u32 adc_clk_khz)
856 {
857 	struct at91_adc_state *st = iio_priv(idev);
858 	u32 reg = 0;
859 	u32 tssctim = 0;
860 	int i = 0;
861 
862 	/* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
863 	 * pen detect noise.
864 	 * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
865 	 */
866 	st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
867 				 1000, 1);
868 
869 	while (st->ts_pendbc >> ++i)
870 		;	/* Empty! Find the shift offset */
871 	if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
872 		st->ts_pendbc = i;
873 	else
874 		st->ts_pendbc = i - 1;
875 
876 	if (!st->caps->has_tsmr) {
877 		reg = at91_adc_readl(st, AT91_ADC_MR);
878 		reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
879 
880 		reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
881 		at91_adc_writel(st, AT91_ADC_MR, reg);
882 
883 		reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
884 		at91_adc_writel(st, AT91_ADC_TSR, reg);
885 
886 		st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
887 						    adc_clk_khz / 1000) - 1, 1);
888 
889 		return 0;
890 	}
891 
892 	/* Touchscreen Switches Closure time needed for allowing the value to
893 	 * stabilize.
894 	 * Switch Closure Time = (TSSCTIM * 4) ADCClock periods
895 	 */
896 	tssctim = DIV_ROUND_UP(TOUCH_SCTIM_US * adc_clk_khz / 1000, 4);
897 	dev_dbg(&idev->dev, "adc_clk at: %d KHz, tssctim at: %d\n",
898 		adc_clk_khz, tssctim);
899 
900 	if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
901 		reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
902 	else
903 		reg = AT91_ADC_TSMR_TSMODE_5WIRE;
904 
905 	reg |= AT91_ADC_TSMR_SCTIM_(tssctim) & AT91_ADC_TSMR_SCTIM;
906 	reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
907 	       & AT91_ADC_TSMR_TSAV;
908 	reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
909 	reg |= AT91_ADC_TSMR_NOTSDMA;
910 	reg |= AT91_ADC_TSMR_PENDET_ENA;
911 	reg |= 0x03 << 8;	/* TSFREQ, needs to be bigger than TSAV */
912 
913 	at91_adc_writel(st, AT91_ADC_TSMR, reg);
914 
915 	/* Change adc internal resistor value for better pen detection,
916 	 * default value is 100 kOhm.
917 	 * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
918 	 * option only available on ES2 and higher
919 	 */
920 	at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
921 			& AT91_ADC_ACR_PENDETSENS);
922 
923 	/* Sample Period Time = (TRGPER + 1) / ADCClock */
924 	st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
925 			adc_clk_khz / 1000) - 1, 1);
926 
927 	return 0;
928 }
929 
930 static int at91_ts_register(struct iio_dev *idev,
931 		struct platform_device *pdev)
932 {
933 	struct at91_adc_state *st = iio_priv(idev);
934 	struct input_dev *input;
935 	int ret;
936 
937 	input = input_allocate_device();
938 	if (!input) {
939 		dev_err(&idev->dev, "Failed to allocate TS device!\n");
940 		return -ENOMEM;
941 	}
942 
943 	input->name = DRIVER_NAME;
944 	input->id.bustype = BUS_HOST;
945 	input->dev.parent = &pdev->dev;
946 	input->open = atmel_ts_open;
947 	input->close = atmel_ts_close;
948 
949 	__set_bit(EV_ABS, input->evbit);
950 	__set_bit(EV_KEY, input->evbit);
951 	__set_bit(BTN_TOUCH, input->keybit);
952 	if (st->caps->has_tsmr) {
953 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
954 				     0, 0);
955 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
956 				     0, 0);
957 		input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
958 	} else {
959 		if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
960 			dev_err(&pdev->dev,
961 				"This touchscreen controller only support 4 wires\n");
962 			ret = -EINVAL;
963 			goto err;
964 		}
965 
966 		input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
967 				     0, 0);
968 		input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
969 				     0, 0);
970 	}
971 
972 	st->ts_input = input;
973 	input_set_drvdata(input, st);
974 
975 	ret = input_register_device(input);
976 	if (ret)
977 		goto err;
978 
979 	return ret;
980 
981 err:
982 	input_free_device(st->ts_input);
983 	return ret;
984 }
985 
986 static void at91_ts_unregister(struct at91_adc_state *st)
987 {
988 	input_unregister_device(st->ts_input);
989 }
990 
991 static int at91_adc_probe(struct platform_device *pdev)
992 {
993 	unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
994 	struct device_node *node = pdev->dev.of_node;
995 	int ret;
996 	struct iio_dev *idev;
997 	struct at91_adc_state *st;
998 	u32 reg, prop;
999 	char *s;
1000 
1001 	idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
1002 	if (!idev)
1003 		return -ENOMEM;
1004 
1005 	st = iio_priv(idev);
1006 
1007 	st->caps = of_device_get_match_data(&pdev->dev);
1008 
1009 	st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
1010 
1011 	if (of_property_read_u32(node, "atmel,adc-channels-used", &prop))
1012 		return dev_err_probe(&idev->dev, -EINVAL,
1013 				     "Missing adc-channels-used property in the DT.\n");
1014 	st->channels_mask = prop;
1015 
1016 	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
1017 
1018 	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop))
1019 		return dev_err_probe(&idev->dev, -EINVAL,
1020 				     "Missing adc-startup-time property in the DT.\n");
1021 	st->startup_time = prop;
1022 
1023 	prop = 0;
1024 	of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
1025 	st->sample_hold_time = prop;
1026 
1027 	if (of_property_read_u32(node, "atmel,adc-vref", &prop))
1028 		return dev_err_probe(&idev->dev, -EINVAL,
1029 				     "Missing adc-vref property in the DT.\n");
1030 	st->vref_mv = prop;
1031 
1032 	st->res = st->caps->high_res_bits;
1033 	if (st->caps->low_res_bits &&
1034 	    !of_property_read_string(node, "atmel,adc-use-res", (const char **)&s)
1035 	    && !strcmp(s, "lowres"))
1036 		st->res = st->caps->low_res_bits;
1037 
1038 	dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
1039 
1040 	st->registers = &st->caps->registers;
1041 	st->num_channels = st->caps->num_channels;
1042 
1043 	/* Check if touchscreen is supported. */
1044 	if (st->caps->has_ts) {
1045 		ret = at91_adc_probe_dt_ts(node, st, &idev->dev);
1046 		if (ret)
1047 			return ret;
1048 	}
1049 
1050 	platform_set_drvdata(pdev, idev);
1051 
1052 	idev->name = dev_name(&pdev->dev);
1053 	idev->modes = INDIO_DIRECT_MODE;
1054 	idev->info = &at91_adc_info;
1055 
1056 	st->irq = platform_get_irq(pdev, 0);
1057 	if (st->irq < 0)
1058 		return -ENODEV;
1059 
1060 	st->reg_base = devm_platform_ioremap_resource(pdev, 0);
1061 	if (IS_ERR(st->reg_base))
1062 		return PTR_ERR(st->reg_base);
1063 
1064 	/*
1065 	 * Disable all IRQs before setting up the handler
1066 	 */
1067 	at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
1068 	at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
1069 
1070 	if (st->caps->has_tsmr)
1071 		ret = devm_request_irq(&pdev->dev, st->irq,
1072 				       at91_adc_9x5_interrupt, 0,
1073 				       pdev->dev.driver->name, idev);
1074 	else
1075 		ret = devm_request_irq(&pdev->dev, st->irq,
1076 				       at91_adc_rl_interrupt, 0,
1077 				       pdev->dev.driver->name, idev);
1078 	if (ret)
1079 		return dev_err_probe(&pdev->dev, ret,
1080 				     "Failed to allocate IRQ.\n");
1081 
1082 	st->clk = devm_clk_get_enabled(&pdev->dev, "adc_clk");
1083 	if (IS_ERR(st->clk))
1084 		return dev_err_probe(&pdev->dev, PTR_ERR(st->clk),
1085 				     "Could not prepare or enable the clock.\n");
1086 
1087 	st->adc_clk = devm_clk_get_enabled(&pdev->dev, "adc_op_clk");
1088 	if (IS_ERR(st->adc_clk))
1089 		return dev_err_probe(&pdev->dev, PTR_ERR(st->adc_clk),
1090 				     "Could not prepare or enable the ADC clock.\n");
1091 
1092 	/*
1093 	 * Prescaler rate computation using the formula from the Atmel's
1094 	 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
1095 	 * specified by the electrical characteristics of the board.
1096 	 */
1097 	mstrclk = clk_get_rate(st->clk);
1098 	adc_clk = clk_get_rate(st->adc_clk);
1099 	adc_clk_khz = adc_clk / 1000;
1100 
1101 	dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
1102 		mstrclk, adc_clk);
1103 
1104 	prsc = (mstrclk / (2 * adc_clk)) - 1;
1105 
1106 	if (!st->startup_time)
1107 		return dev_err_probe(&pdev->dev, -EINVAL,
1108 				     "No startup time available.\n");
1109 	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
1110 
1111 	/*
1112 	 * a minimal Sample and Hold Time is necessary for the ADC to guarantee
1113 	 * the best converted final value between two channels selection
1114 	 * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
1115 	 */
1116 	if (st->sample_hold_time > 0)
1117 		shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000)
1118 				 - 1, 1);
1119 	else
1120 		shtim = 0;
1121 
1122 	reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
1123 	reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
1124 	if (st->res == st->caps->low_res_bits)
1125 		reg |= AT91_ADC_LOWRES;
1126 	if (st->sleep_mode)
1127 		reg |= AT91_ADC_SLEEP;
1128 	reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
1129 	at91_adc_writel(st, AT91_ADC_MR, reg);
1130 
1131 	/* Setup the ADC channels available on the board */
1132 	ret = at91_adc_channel_init(idev);
1133 	if (ret < 0)
1134 		return dev_err_probe(&pdev->dev, ret,
1135 				     "Couldn't initialize the channels.\n");
1136 
1137 	init_waitqueue_head(&st->wq_data_avail);
1138 	mutex_init(&st->lock);
1139 
1140 	/*
1141 	 * Since touch screen will set trigger register as period trigger. So
1142 	 * when touch screen is enabled, then we have to disable hardware
1143 	 * trigger for classic adc.
1144 	 */
1145 	if (!st->touchscreen_type) {
1146 		ret = at91_adc_buffer_init(idev);
1147 		if (ret < 0)
1148 			return dev_err_probe(&pdev->dev, ret,
1149 					     "Couldn't initialize the buffer.\n");
1150 
1151 		ret = at91_adc_trigger_init(idev);
1152 		if (ret < 0) {
1153 			dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
1154 			at91_adc_buffer_remove(idev);
1155 			return ret;
1156 		}
1157 	} else {
1158 		ret = at91_ts_register(idev, pdev);
1159 		if (ret)
1160 			return ret;
1161 
1162 		at91_ts_hw_init(idev, adc_clk_khz);
1163 	}
1164 
1165 	ret = iio_device_register(idev);
1166 	if (ret < 0) {
1167 		dev_err(&pdev->dev, "Couldn't register the device.\n");
1168 		goto error_iio_device_register;
1169 	}
1170 
1171 	return 0;
1172 
1173 error_iio_device_register:
1174 	if (!st->touchscreen_type) {
1175 		at91_adc_trigger_remove(idev);
1176 		at91_adc_buffer_remove(idev);
1177 	} else {
1178 		at91_ts_unregister(st);
1179 	}
1180 	return ret;
1181 }
1182 
1183 static void at91_adc_remove(struct platform_device *pdev)
1184 {
1185 	struct iio_dev *idev = platform_get_drvdata(pdev);
1186 	struct at91_adc_state *st = iio_priv(idev);
1187 
1188 	iio_device_unregister(idev);
1189 	if (!st->touchscreen_type) {
1190 		at91_adc_trigger_remove(idev);
1191 		at91_adc_buffer_remove(idev);
1192 	} else {
1193 		at91_ts_unregister(st);
1194 	}
1195 }
1196 
1197 static int at91_adc_suspend(struct device *dev)
1198 {
1199 	struct iio_dev *idev = dev_get_drvdata(dev);
1200 	struct at91_adc_state *st = iio_priv(idev);
1201 
1202 	pinctrl_pm_select_sleep_state(dev);
1203 	clk_disable_unprepare(st->clk);
1204 
1205 	return 0;
1206 }
1207 
1208 static int at91_adc_resume(struct device *dev)
1209 {
1210 	struct iio_dev *idev = dev_get_drvdata(dev);
1211 	struct at91_adc_state *st = iio_priv(idev);
1212 
1213 	clk_prepare_enable(st->clk);
1214 	pinctrl_pm_select_default_state(dev);
1215 
1216 	return 0;
1217 }
1218 
1219 static DEFINE_SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend,
1220 				at91_adc_resume);
1221 
1222 static const struct at91_adc_trigger at91sam9260_triggers[] = {
1223 	{ .name = "timer-counter-0", .value = 0x1 },
1224 	{ .name = "timer-counter-1", .value = 0x3 },
1225 	{ .name = "timer-counter-2", .value = 0x5 },
1226 	{ .name = "external", .value = 0xd, .is_external = true },
1227 };
1228 
1229 static struct at91_adc_caps at91sam9260_caps = {
1230 	.calc_startup_ticks = calc_startup_ticks_9260,
1231 	.num_channels = 4,
1232 	.low_res_bits = 8,
1233 	.high_res_bits = 10,
1234 	.registers = {
1235 		.channel_base = AT91_ADC_CHR(0),
1236 		.drdy_mask = AT91_ADC_DRDY,
1237 		.status_register = AT91_ADC_SR,
1238 		.trigger_register = AT91_ADC_TRGR_9260,
1239 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1240 		.mr_startup_mask = AT91_ADC_STARTUP_9260,
1241 	},
1242 	.triggers = at91sam9260_triggers,
1243 	.trigger_number = ARRAY_SIZE(at91sam9260_triggers),
1244 };
1245 
1246 static const struct at91_adc_trigger at91sam9x5_triggers[] = {
1247 	{ .name = "external-rising", .value = 0x1, .is_external = true },
1248 	{ .name = "external-falling", .value = 0x2, .is_external = true },
1249 	{ .name = "external-any", .value = 0x3, .is_external = true },
1250 	{ .name = "continuous", .value = 0x6 },
1251 };
1252 
1253 static struct at91_adc_caps at91sam9rl_caps = {
1254 	.has_ts = true,
1255 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1256 	.num_channels = 6,
1257 	.low_res_bits = 8,
1258 	.high_res_bits = 10,
1259 	.registers = {
1260 		.channel_base = AT91_ADC_CHR(0),
1261 		.drdy_mask = AT91_ADC_DRDY,
1262 		.status_register = AT91_ADC_SR,
1263 		.trigger_register = AT91_ADC_TRGR_9G45,
1264 		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1265 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1266 	},
1267 	.triggers = at91sam9x5_triggers,
1268 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1269 };
1270 
1271 static struct at91_adc_caps at91sam9g45_caps = {
1272 	.has_ts = true,
1273 	.calc_startup_ticks = calc_startup_ticks_9260,	/* same as 9260 */
1274 	.num_channels = 8,
1275 	.low_res_bits = 8,
1276 	.high_res_bits = 10,
1277 	.registers = {
1278 		.channel_base = AT91_ADC_CHR(0),
1279 		.drdy_mask = AT91_ADC_DRDY,
1280 		.status_register = AT91_ADC_SR,
1281 		.trigger_register = AT91_ADC_TRGR_9G45,
1282 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1283 		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
1284 	},
1285 	.triggers = at91sam9x5_triggers,
1286 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1287 };
1288 
1289 static struct at91_adc_caps at91sam9x5_caps = {
1290 	.has_ts = true,
1291 	.has_tsmr = true,
1292 	.ts_filter_average = 3,
1293 	.ts_pen_detect_sensitivity = 2,
1294 	.calc_startup_ticks = calc_startup_ticks_9x5,
1295 	.num_channels = 12,
1296 	.low_res_bits = 8,
1297 	.high_res_bits = 10,
1298 	.registers = {
1299 		.channel_base = AT91_ADC_CDR0_9X5,
1300 		.drdy_mask = AT91_ADC_SR_DRDY_9X5,
1301 		.status_register = AT91_ADC_SR_9X5,
1302 		.trigger_register = AT91_ADC_TRGR_9X5,
1303 		/* prescal mask is same as 9G45 */
1304 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1305 		.mr_startup_mask = AT91_ADC_STARTUP_9X5,
1306 	},
1307 	.triggers = at91sam9x5_triggers,
1308 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1309 };
1310 
1311 static struct at91_adc_caps sama5d3_caps = {
1312 	.has_ts = true,
1313 	.has_tsmr = true,
1314 	.ts_filter_average = 3,
1315 	.ts_pen_detect_sensitivity = 2,
1316 	.calc_startup_ticks = calc_startup_ticks_9x5,
1317 	.num_channels = 12,
1318 	.low_res_bits = 0,
1319 	.high_res_bits = 12,
1320 	.registers = {
1321 		.channel_base = AT91_ADC_CDR0_9X5,
1322 		.drdy_mask = AT91_ADC_SR_DRDY_9X5,
1323 		.status_register = AT91_ADC_SR_9X5,
1324 		.trigger_register = AT91_ADC_TRGR_9X5,
1325 		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1326 		.mr_startup_mask = AT91_ADC_STARTUP_9X5,
1327 	},
1328 	.triggers = at91sam9x5_triggers,
1329 	.trigger_number = ARRAY_SIZE(at91sam9x5_triggers),
1330 };
1331 
1332 static const struct of_device_id at91_adc_dt_ids[] = {
1333 	{ .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
1334 	{ .compatible = "atmel,at91sam9rl-adc", .data = &at91sam9rl_caps },
1335 	{ .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
1336 	{ .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
1337 	{ .compatible = "atmel,sama5d3-adc", .data = &sama5d3_caps },
1338 	{ }
1339 };
1340 MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
1341 
1342 static struct platform_driver at91_adc_driver = {
1343 	.probe = at91_adc_probe,
1344 	.remove_new = at91_adc_remove,
1345 	.driver = {
1346 		   .name = DRIVER_NAME,
1347 		   .of_match_table = at91_adc_dt_ids,
1348 		   .pm = pm_sleep_ptr(&at91_adc_pm_ops),
1349 	},
1350 };
1351 
1352 module_platform_driver(at91_adc_driver);
1353 
1354 MODULE_LICENSE("GPL");
1355 MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
1356 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1357