1 /*
2  * TI ADC MFD driver
3  *
4  * Copyright (C) 2012 Texas Instruments Incorporated - https://www.ti.com/
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation version 2.
9  *
10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
11  * kind, whether express or implied; without even the implied warranty
12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
21 #include <linux/platform_device.h>
22 #include <linux/io.h>
23 #include <linux/iio/iio.h>
24 #include <linux/of.h>
25 #include <linux/of_device.h>
26 #include <linux/iio/machine.h>
27 #include <linux/iio/driver.h>
28 
29 #include <linux/mfd/ti_am335x_tscadc.h>
30 #include <linux/iio/buffer.h>
31 #include <linux/iio/kfifo_buf.h>
32 
33 #include <linux/dmaengine.h>
34 #include <linux/dma-mapping.h>
35 
36 #define DMA_BUFFER_SIZE		SZ_2K
37 
38 struct tiadc_dma {
39 	struct dma_slave_config	conf;
40 	struct dma_chan		*chan;
41 	dma_addr_t		addr;
42 	dma_cookie_t		cookie;
43 	u8			*buf;
44 	int			current_period;
45 	int			period_size;
46 	u8			fifo_thresh;
47 };
48 
49 struct tiadc_device {
50 	struct ti_tscadc_dev *mfd_tscadc;
51 	struct tiadc_dma dma;
52 	struct mutex fifo1_lock; /* to protect fifo access */
53 	int channels;
54 	int total_ch_enabled;
55 	u8 channel_line[8];
56 	u8 channel_step[8];
57 	int buffer_en_ch_steps;
58 	u16 data[8];
59 	u32 open_delay[8], sample_delay[8], step_avg[8];
60 };
61 
tiadc_readl(struct tiadc_device * adc,unsigned int reg)62 static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
63 {
64 	return readl(adc->mfd_tscadc->tscadc_base + reg);
65 }
66 
tiadc_writel(struct tiadc_device * adc,unsigned int reg,unsigned int val)67 static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
68 					unsigned int val)
69 {
70 	writel(val, adc->mfd_tscadc->tscadc_base + reg);
71 }
72 
get_adc_step_mask(struct tiadc_device * adc_dev)73 static u32 get_adc_step_mask(struct tiadc_device *adc_dev)
74 {
75 	u32 step_en;
76 
77 	step_en = ((1 << adc_dev->channels) - 1);
78 	step_en <<= TOTAL_STEPS - adc_dev->channels + 1;
79 	return step_en;
80 }
81 
get_adc_chan_step_mask(struct tiadc_device * adc_dev,struct iio_chan_spec const * chan)82 static u32 get_adc_chan_step_mask(struct tiadc_device *adc_dev,
83 		struct iio_chan_spec const *chan)
84 {
85 	int i;
86 
87 	for (i = 0; i < ARRAY_SIZE(adc_dev->channel_step); i++) {
88 		if (chan->channel == adc_dev->channel_line[i]) {
89 			u32 step;
90 
91 			step = adc_dev->channel_step[i];
92 			/* +1 for the charger */
93 			return 1 << (step + 1);
94 		}
95 	}
96 	WARN_ON(1);
97 	return 0;
98 }
99 
get_adc_step_bit(struct tiadc_device * adc_dev,int chan)100 static u32 get_adc_step_bit(struct tiadc_device *adc_dev, int chan)
101 {
102 	return 1 << adc_dev->channel_step[chan];
103 }
104 
tiadc_step_config(struct iio_dev * indio_dev)105 static void tiadc_step_config(struct iio_dev *indio_dev)
106 {
107 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
108 	struct device *dev = adc_dev->mfd_tscadc->dev;
109 	unsigned int stepconfig;
110 	int i, steps = 0;
111 
112 	/*
113 	 * There are 16 configurable steps and 8 analog input
114 	 * lines available which are shared between Touchscreen and ADC.
115 	 *
116 	 * Steps forwards i.e. from 0 towards 16 are used by ADC
117 	 * depending on number of input lines needed.
118 	 * Channel would represent which analog input
119 	 * needs to be given to ADC to digitalize data.
120 	 */
121 
122 
123 	for (i = 0; i < adc_dev->channels; i++) {
124 		int chan;
125 
126 		chan = adc_dev->channel_line[i];
127 
128 		if (adc_dev->step_avg[i] > STEPCONFIG_AVG_16) {
129 			dev_warn(dev, "chan %d step_avg truncating to %d\n",
130 				 chan, STEPCONFIG_AVG_16);
131 			adc_dev->step_avg[i] = STEPCONFIG_AVG_16;
132 		}
133 
134 		if (adc_dev->step_avg[i])
135 			stepconfig =
136 			STEPCONFIG_AVG(ffs(adc_dev->step_avg[i]) - 1) |
137 			STEPCONFIG_FIFO1;
138 		else
139 			stepconfig = STEPCONFIG_FIFO1;
140 
141 		if (iio_buffer_enabled(indio_dev))
142 			stepconfig |= STEPCONFIG_MODE_SWCNT;
143 
144 		tiadc_writel(adc_dev, REG_STEPCONFIG(steps),
145 				stepconfig | STEPCONFIG_INP(chan) |
146 				STEPCONFIG_INM_ADCREFM |
147 				STEPCONFIG_RFP_VREFP |
148 				STEPCONFIG_RFM_VREFN);
149 
150 		if (adc_dev->open_delay[i] > STEPDELAY_OPEN_MASK) {
151 			dev_warn(dev, "chan %d open delay truncating to 0x3FFFF\n",
152 				 chan);
153 			adc_dev->open_delay[i] = STEPDELAY_OPEN_MASK;
154 		}
155 
156 		if (adc_dev->sample_delay[i] > 0xFF) {
157 			dev_warn(dev, "chan %d sample delay truncating to 0xFF\n",
158 				 chan);
159 			adc_dev->sample_delay[i] = 0xFF;
160 		}
161 
162 		tiadc_writel(adc_dev, REG_STEPDELAY(steps),
163 				STEPDELAY_OPEN(adc_dev->open_delay[i]) |
164 				STEPDELAY_SAMPLE(adc_dev->sample_delay[i]));
165 
166 		adc_dev->channel_step[i] = steps;
167 		steps++;
168 	}
169 }
170 
tiadc_irq_h(int irq,void * private)171 static irqreturn_t tiadc_irq_h(int irq, void *private)
172 {
173 	struct iio_dev *indio_dev = private;
174 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
175 	unsigned int status, config, adc_fsm;
176 	unsigned short count = 0;
177 
178 	status = tiadc_readl(adc_dev, REG_IRQSTATUS);
179 
180 	/*
181 	 * ADC and touchscreen share the IRQ line.
182 	 * FIFO0 interrupts are used by TSC. Handle FIFO1 IRQs here only
183 	 */
184 	if (status & IRQENB_FIFO1OVRRUN) {
185 		/* FIFO Overrun. Clear flag. Disable/Enable ADC to recover */
186 		config = tiadc_readl(adc_dev, REG_CTRL);
187 		config &= ~(CNTRLREG_TSCSSENB);
188 		tiadc_writel(adc_dev, REG_CTRL, config);
189 		tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1OVRRUN
190 				| IRQENB_FIFO1UNDRFLW | IRQENB_FIFO1THRES);
191 
192 		/* wait for idle state.
193 		 * ADC needs to finish the current conversion
194 		 * before disabling the module
195 		 */
196 		do {
197 			adc_fsm = tiadc_readl(adc_dev, REG_ADCFSM);
198 		} while (adc_fsm != 0x10 && count++ < 100);
199 
200 		tiadc_writel(adc_dev, REG_CTRL, (config | CNTRLREG_TSCSSENB));
201 		return IRQ_HANDLED;
202 	} else if (status & IRQENB_FIFO1THRES) {
203 		/* Disable irq and wake worker thread */
204 		tiadc_writel(adc_dev, REG_IRQCLR, IRQENB_FIFO1THRES);
205 		return IRQ_WAKE_THREAD;
206 	}
207 
208 	return IRQ_NONE;
209 }
210 
tiadc_worker_h(int irq,void * private)211 static irqreturn_t tiadc_worker_h(int irq, void *private)
212 {
213 	struct iio_dev *indio_dev = private;
214 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
215 	int i, k, fifo1count, read;
216 	u16 *data = adc_dev->data;
217 
218 	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
219 	for (k = 0; k < fifo1count; k = k + i) {
220 		for (i = 0; i < (indio_dev->scan_bytes)/2; i++) {
221 			read = tiadc_readl(adc_dev, REG_FIFO1);
222 			data[i] = read & FIFOREAD_DATA_MASK;
223 		}
224 		iio_push_to_buffers(indio_dev, (u8 *) data);
225 	}
226 
227 	tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES);
228 	tiadc_writel(adc_dev, REG_IRQENABLE, IRQENB_FIFO1THRES);
229 
230 	return IRQ_HANDLED;
231 }
232 
tiadc_dma_rx_complete(void * param)233 static void tiadc_dma_rx_complete(void *param)
234 {
235 	struct iio_dev *indio_dev = param;
236 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
237 	struct tiadc_dma *dma = &adc_dev->dma;
238 	u8 *data;
239 	int i;
240 
241 	data = dma->buf + dma->current_period * dma->period_size;
242 	dma->current_period = 1 - dma->current_period; /* swap the buffer ID */
243 
244 	for (i = 0; i < dma->period_size; i += indio_dev->scan_bytes) {
245 		iio_push_to_buffers(indio_dev, data);
246 		data += indio_dev->scan_bytes;
247 	}
248 }
249 
tiadc_start_dma(struct iio_dev * indio_dev)250 static int tiadc_start_dma(struct iio_dev *indio_dev)
251 {
252 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
253 	struct tiadc_dma *dma = &adc_dev->dma;
254 	struct dma_async_tx_descriptor *desc;
255 
256 	dma->current_period = 0; /* We start to fill period 0 */
257 	/*
258 	 * Make the fifo thresh as the multiple of total number of
259 	 * channels enabled, so make sure that cyclic DMA period
260 	 * length is also a multiple of total number of channels
261 	 * enabled. This ensures that no invalid data is reported
262 	 * to the stack via iio_push_to_buffers().
263 	 */
264 	dma->fifo_thresh = rounddown(FIFO1_THRESHOLD + 1,
265 				     adc_dev->total_ch_enabled) - 1;
266 	/* Make sure that period length is multiple of fifo thresh level */
267 	dma->period_size = rounddown(DMA_BUFFER_SIZE / 2,
268 				    (dma->fifo_thresh + 1) * sizeof(u16));
269 
270 	dma->conf.src_maxburst = dma->fifo_thresh + 1;
271 	dmaengine_slave_config(dma->chan, &dma->conf);
272 
273 	desc = dmaengine_prep_dma_cyclic(dma->chan, dma->addr,
274 					 dma->period_size * 2,
275 					 dma->period_size, DMA_DEV_TO_MEM,
276 					 DMA_PREP_INTERRUPT);
277 	if (!desc)
278 		return -EBUSY;
279 
280 	desc->callback = tiadc_dma_rx_complete;
281 	desc->callback_param = indio_dev;
282 
283 	dma->cookie = dmaengine_submit(desc);
284 
285 	dma_async_issue_pending(dma->chan);
286 
287 	tiadc_writel(adc_dev, REG_FIFO1THR, dma->fifo_thresh);
288 	tiadc_writel(adc_dev, REG_DMA1REQ, dma->fifo_thresh);
289 	tiadc_writel(adc_dev, REG_DMAENABLE_SET, DMA_FIFO1);
290 
291 	return 0;
292 }
293 
tiadc_buffer_preenable(struct iio_dev * indio_dev)294 static int tiadc_buffer_preenable(struct iio_dev *indio_dev)
295 {
296 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
297 	int i, fifo1count;
298 
299 	tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES |
300 				IRQENB_FIFO1OVRRUN |
301 				IRQENB_FIFO1UNDRFLW));
302 
303 	/* Flush FIFO. Needed in corner cases in simultaneous tsc/adc use */
304 	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
305 	for (i = 0; i < fifo1count; i++)
306 		tiadc_readl(adc_dev, REG_FIFO1);
307 
308 	return 0;
309 }
310 
tiadc_buffer_postenable(struct iio_dev * indio_dev)311 static int tiadc_buffer_postenable(struct iio_dev *indio_dev)
312 {
313 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
314 	struct tiadc_dma *dma = &adc_dev->dma;
315 	unsigned int irq_enable;
316 	unsigned int enb = 0;
317 	u8 bit;
318 
319 	tiadc_step_config(indio_dev);
320 	for_each_set_bit(bit, indio_dev->active_scan_mask, adc_dev->channels) {
321 		enb |= (get_adc_step_bit(adc_dev, bit) << 1);
322 		adc_dev->total_ch_enabled++;
323 	}
324 	adc_dev->buffer_en_ch_steps = enb;
325 
326 	if (dma->chan)
327 		tiadc_start_dma(indio_dev);
328 
329 	am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, enb);
330 
331 	tiadc_writel(adc_dev,  REG_IRQSTATUS, IRQENB_FIFO1THRES
332 				| IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW);
333 
334 	irq_enable = IRQENB_FIFO1OVRRUN;
335 	if (!dma->chan)
336 		irq_enable |= IRQENB_FIFO1THRES;
337 	tiadc_writel(adc_dev,  REG_IRQENABLE, irq_enable);
338 
339 	return 0;
340 }
341 
tiadc_buffer_predisable(struct iio_dev * indio_dev)342 static int tiadc_buffer_predisable(struct iio_dev *indio_dev)
343 {
344 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
345 	struct tiadc_dma *dma = &adc_dev->dma;
346 	int fifo1count, i;
347 
348 	tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES |
349 				IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW));
350 	am335x_tsc_se_clr(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps);
351 	adc_dev->buffer_en_ch_steps = 0;
352 	adc_dev->total_ch_enabled = 0;
353 	if (dma->chan) {
354 		tiadc_writel(adc_dev, REG_DMAENABLE_CLEAR, 0x2);
355 		dmaengine_terminate_async(dma->chan);
356 	}
357 
358 	/* Flush FIFO of leftover data in the time it takes to disable adc */
359 	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
360 	for (i = 0; i < fifo1count; i++)
361 		tiadc_readl(adc_dev, REG_FIFO1);
362 
363 	return 0;
364 }
365 
tiadc_buffer_postdisable(struct iio_dev * indio_dev)366 static int tiadc_buffer_postdisable(struct iio_dev *indio_dev)
367 {
368 	tiadc_step_config(indio_dev);
369 
370 	return 0;
371 }
372 
373 static const struct iio_buffer_setup_ops tiadc_buffer_setup_ops = {
374 	.preenable = &tiadc_buffer_preenable,
375 	.postenable = &tiadc_buffer_postenable,
376 	.predisable = &tiadc_buffer_predisable,
377 	.postdisable = &tiadc_buffer_postdisable,
378 };
379 
tiadc_iio_buffered_hardware_setup(struct device * dev,struct iio_dev * indio_dev,irqreturn_t (* pollfunc_bh)(int irq,void * p),irqreturn_t (* pollfunc_th)(int irq,void * p),int irq,unsigned long flags,const struct iio_buffer_setup_ops * setup_ops)380 static int tiadc_iio_buffered_hardware_setup(struct device *dev,
381 	struct iio_dev *indio_dev,
382 	irqreturn_t (*pollfunc_bh)(int irq, void *p),
383 	irqreturn_t (*pollfunc_th)(int irq, void *p),
384 	int irq,
385 	unsigned long flags,
386 	const struct iio_buffer_setup_ops *setup_ops)
387 {
388 	int ret;
389 
390 	ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
391 					  INDIO_BUFFER_SOFTWARE,
392 					  setup_ops);
393 	if (ret)
394 		return ret;
395 
396 	return devm_request_threaded_irq(dev, irq, pollfunc_th, pollfunc_bh,
397 				flags, indio_dev->name, indio_dev);
398 }
399 
400 static const char * const chan_name_ain[] = {
401 	"AIN0",
402 	"AIN1",
403 	"AIN2",
404 	"AIN3",
405 	"AIN4",
406 	"AIN5",
407 	"AIN6",
408 	"AIN7",
409 };
410 
tiadc_channel_init(struct device * dev,struct iio_dev * indio_dev,int channels)411 static int tiadc_channel_init(struct device *dev, struct iio_dev *indio_dev,
412 			      int channels)
413 {
414 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
415 	struct iio_chan_spec *chan_array;
416 	struct iio_chan_spec *chan;
417 	int i;
418 
419 	indio_dev->num_channels = channels;
420 	chan_array = devm_kcalloc(dev, channels, sizeof(*chan_array),
421 				  GFP_KERNEL);
422 	if (chan_array == NULL)
423 		return -ENOMEM;
424 
425 	chan = chan_array;
426 	for (i = 0; i < channels; i++, chan++) {
427 
428 		chan->type = IIO_VOLTAGE;
429 		chan->indexed = 1;
430 		chan->channel = adc_dev->channel_line[i];
431 		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
432 		chan->datasheet_name = chan_name_ain[chan->channel];
433 		chan->scan_index = i;
434 		chan->scan_type.sign = 'u';
435 		chan->scan_type.realbits = 12;
436 		chan->scan_type.storagebits = 16;
437 	}
438 
439 	indio_dev->channels = chan_array;
440 
441 	return 0;
442 }
443 
tiadc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)444 static int tiadc_read_raw(struct iio_dev *indio_dev,
445 		struct iio_chan_spec const *chan,
446 		int *val, int *val2, long mask)
447 {
448 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
449 	int ret = IIO_VAL_INT;
450 	int i, map_val;
451 	unsigned int fifo1count, read, stepid;
452 	bool found = false;
453 	u32 step_en;
454 	unsigned long timeout;
455 
456 	if (iio_buffer_enabled(indio_dev))
457 		return -EBUSY;
458 
459 	step_en = get_adc_chan_step_mask(adc_dev, chan);
460 	if (!step_en)
461 		return -EINVAL;
462 
463 	mutex_lock(&adc_dev->fifo1_lock);
464 	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
465 	while (fifo1count--)
466 		tiadc_readl(adc_dev, REG_FIFO1);
467 
468 	am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en);
469 
470 	timeout = jiffies + msecs_to_jiffies
471 				(IDLE_TIMEOUT * adc_dev->channels);
472 	/* Wait for Fifo threshold interrupt */
473 	while (1) {
474 		fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
475 		if (fifo1count)
476 			break;
477 
478 		if (time_after(jiffies, timeout)) {
479 			am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
480 			ret = -EAGAIN;
481 			goto err_unlock;
482 		}
483 	}
484 	map_val = adc_dev->channel_step[chan->scan_index];
485 
486 	/*
487 	 * We check the complete FIFO. We programmed just one entry but in case
488 	 * something went wrong we left empty handed (-EAGAIN previously) and
489 	 * then the value apeared somehow in the FIFO we would have two entries.
490 	 * Therefore we read every item and keep only the latest version of the
491 	 * requested channel.
492 	 */
493 	for (i = 0; i < fifo1count; i++) {
494 		read = tiadc_readl(adc_dev, REG_FIFO1);
495 		stepid = read & FIFOREAD_CHNLID_MASK;
496 		stepid = stepid >> 0x10;
497 
498 		if (stepid == map_val) {
499 			read = read & FIFOREAD_DATA_MASK;
500 			found = true;
501 			*val = (u16) read;
502 		}
503 	}
504 	am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
505 
506 	if (!found)
507 		ret =  -EBUSY;
508 
509 err_unlock:
510 	mutex_unlock(&adc_dev->fifo1_lock);
511 	return ret;
512 }
513 
514 static const struct iio_info tiadc_info = {
515 	.read_raw = &tiadc_read_raw,
516 };
517 
tiadc_request_dma(struct platform_device * pdev,struct tiadc_device * adc_dev)518 static int tiadc_request_dma(struct platform_device *pdev,
519 			     struct tiadc_device *adc_dev)
520 {
521 	struct tiadc_dma	*dma = &adc_dev->dma;
522 	dma_cap_mask_t		mask;
523 
524 	/* Default slave configuration parameters */
525 	dma->conf.direction = DMA_DEV_TO_MEM;
526 	dma->conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
527 	dma->conf.src_addr = adc_dev->mfd_tscadc->tscadc_phys_base + REG_FIFO1;
528 
529 	dma_cap_zero(mask);
530 	dma_cap_set(DMA_CYCLIC, mask);
531 
532 	/* Get a channel for RX */
533 	dma->chan = dma_request_chan(adc_dev->mfd_tscadc->dev, "fifo1");
534 	if (IS_ERR(dma->chan)) {
535 		int ret = PTR_ERR(dma->chan);
536 
537 		dma->chan = NULL;
538 		return ret;
539 	}
540 
541 	/* RX buffer */
542 	dma->buf = dma_alloc_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE,
543 				      &dma->addr, GFP_KERNEL);
544 	if (!dma->buf)
545 		goto err;
546 
547 	return 0;
548 err:
549 	dma_release_channel(dma->chan);
550 	return -ENOMEM;
551 }
552 
tiadc_parse_dt(struct platform_device * pdev,struct tiadc_device * adc_dev)553 static int tiadc_parse_dt(struct platform_device *pdev,
554 			  struct tiadc_device *adc_dev)
555 {
556 	struct device_node *node = pdev->dev.of_node;
557 	struct property *prop;
558 	const __be32 *cur;
559 	int channels = 0;
560 	u32 val;
561 
562 	of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
563 		adc_dev->channel_line[channels] = val;
564 
565 		/* Set Default values for optional DT parameters */
566 		adc_dev->open_delay[channels] = STEPCONFIG_OPENDLY;
567 		adc_dev->sample_delay[channels] = STEPCONFIG_SAMPLEDLY;
568 		adc_dev->step_avg[channels] = 16;
569 
570 		channels++;
571 	}
572 
573 	of_property_read_u32_array(node, "ti,chan-step-avg",
574 				   adc_dev->step_avg, channels);
575 	of_property_read_u32_array(node, "ti,chan-step-opendelay",
576 				   adc_dev->open_delay, channels);
577 	of_property_read_u32_array(node, "ti,chan-step-sampledelay",
578 				   adc_dev->sample_delay, channels);
579 
580 	adc_dev->channels = channels;
581 	return 0;
582 }
583 
tiadc_probe(struct platform_device * pdev)584 static int tiadc_probe(struct platform_device *pdev)
585 {
586 	struct iio_dev		*indio_dev;
587 	struct tiadc_device	*adc_dev;
588 	struct device_node	*node = pdev->dev.of_node;
589 	int			err;
590 
591 	if (!node) {
592 		dev_err(&pdev->dev, "Could not find valid DT data.\n");
593 		return -EINVAL;
594 	}
595 
596 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
597 	if (indio_dev == NULL) {
598 		dev_err(&pdev->dev, "failed to allocate iio device\n");
599 		return -ENOMEM;
600 	}
601 	adc_dev = iio_priv(indio_dev);
602 
603 	adc_dev->mfd_tscadc = ti_tscadc_dev_get(pdev);
604 	tiadc_parse_dt(pdev, adc_dev);
605 
606 	indio_dev->name = dev_name(&pdev->dev);
607 	indio_dev->modes = INDIO_DIRECT_MODE;
608 	indio_dev->info = &tiadc_info;
609 
610 	tiadc_step_config(indio_dev);
611 	tiadc_writel(adc_dev, REG_FIFO1THR, FIFO1_THRESHOLD);
612 	mutex_init(&adc_dev->fifo1_lock);
613 
614 	err = tiadc_channel_init(&pdev->dev, indio_dev, adc_dev->channels);
615 	if (err < 0)
616 		return err;
617 
618 	err = tiadc_iio_buffered_hardware_setup(&pdev->dev, indio_dev,
619 		&tiadc_worker_h,
620 		&tiadc_irq_h,
621 		adc_dev->mfd_tscadc->irq,
622 		IRQF_SHARED,
623 		&tiadc_buffer_setup_ops);
624 
625 	if (err)
626 		goto err_free_channels;
627 
628 	err = iio_device_register(indio_dev);
629 	if (err)
630 		goto err_buffer_unregister;
631 
632 	platform_set_drvdata(pdev, indio_dev);
633 
634 	err = tiadc_request_dma(pdev, adc_dev);
635 	if (err && err == -EPROBE_DEFER)
636 		goto err_dma;
637 
638 	return 0;
639 
640 err_dma:
641 	iio_device_unregister(indio_dev);
642 err_buffer_unregister:
643 err_free_channels:
644 	return err;
645 }
646 
tiadc_remove(struct platform_device * pdev)647 static int tiadc_remove(struct platform_device *pdev)
648 {
649 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
650 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
651 	struct tiadc_dma *dma = &adc_dev->dma;
652 	u32 step_en;
653 
654 	if (dma->chan) {
655 		dma_free_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE,
656 				  dma->buf, dma->addr);
657 		dma_release_channel(dma->chan);
658 	}
659 	iio_device_unregister(indio_dev);
660 
661 	step_en = get_adc_step_mask(adc_dev);
662 	am335x_tsc_se_clr(adc_dev->mfd_tscadc, step_en);
663 
664 	return 0;
665 }
666 
tiadc_suspend(struct device * dev)667 static int __maybe_unused tiadc_suspend(struct device *dev)
668 {
669 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
670 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
671 	unsigned int idle;
672 
673 	idle = tiadc_readl(adc_dev, REG_CTRL);
674 	idle &= ~(CNTRLREG_TSCSSENB);
675 	tiadc_writel(adc_dev, REG_CTRL, (idle |
676 			CNTRLREG_POWERDOWN));
677 
678 	return 0;
679 }
680 
tiadc_resume(struct device * dev)681 static int __maybe_unused tiadc_resume(struct device *dev)
682 {
683 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
684 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
685 	unsigned int restore;
686 
687 	/* Make sure ADC is powered up */
688 	restore = tiadc_readl(adc_dev, REG_CTRL);
689 	restore &= ~(CNTRLREG_POWERDOWN);
690 	tiadc_writel(adc_dev, REG_CTRL, restore);
691 
692 	tiadc_step_config(indio_dev);
693 	am335x_tsc_se_set_cache(adc_dev->mfd_tscadc,
694 			adc_dev->buffer_en_ch_steps);
695 	return 0;
696 }
697 
698 static SIMPLE_DEV_PM_OPS(tiadc_pm_ops, tiadc_suspend, tiadc_resume);
699 
700 static const struct of_device_id ti_adc_dt_ids[] = {
701 	{ .compatible = "ti,am3359-adc", },
702 	{ }
703 };
704 MODULE_DEVICE_TABLE(of, ti_adc_dt_ids);
705 
706 static struct platform_driver tiadc_driver = {
707 	.driver = {
708 		.name   = "TI-am335x-adc",
709 		.pm	= &tiadc_pm_ops,
710 		.of_match_table = ti_adc_dt_ids,
711 	},
712 	.probe	= tiadc_probe,
713 	.remove	= tiadc_remove,
714 };
715 module_platform_driver(tiadc_driver);
716 
717 MODULE_DESCRIPTION("TI ADC controller driver");
718 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
719 MODULE_LICENSE("GPL");
720